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https://dsp.stackexchange.com/questions/83207/what-does-the-two-following-formulas-mean | # What does the two following formulas mean?
I am a bit confused between the following two formulas:
$$f\le \frac{f_s}{2} \tag{1}$$
and:
$$f = \frac{f_s}{N} \tag{2}$$
Now I am given an ACF Plot of a sine/cosine wave and I am asked to find the frequency of the signal if the signal is sampled at 1,000 samples/second. I am asked to use the information given in the ACF plot and the sampling rate of 1,000 samples/second.
In the book "Probability and Stochastic Processes" I find the formula (1) i.e., Nyquist Theorem and at another site, here, I find the formula (2) in use.
I have the above two formulas but I am confused in which formula to use. I tried asking this question before but could not explain it clearly. I hope I have explained it properly this time.
As you say,
$$f\le \frac{f_s}{2} \tag{1}$$
is the Nyquist criterion or frequency. It means that, to avoid aliasing (frequency domain folding), a signal must have frequencies below $$\frac{f_s}{2}$$. This probably won't help you determine the frequency of the ACF.
This equation $$f = \frac{f_s}{N} \tag{2}$$ is saying something different. The value $$\frac{1}{f_s}$$ is the time between samples, or the sampling period. When a signal has $$N$$ samples in one period, that means the period of the signal is $$\frac{N}{f_s}$$.
That means that the frequency of the signal is given by formula (2).
With reference to your (now added) ACF: this is not just a sinusoid. It's a damped sinusoid (it is a sinusoid with, probably, a linear decay).
That means it doesn't make sense to look at the peaks because the peak position will change because of the decay.
The peak that won't change is at Lag $$0$$. Start there.
Then look at the zeros. The zero positions won't change because of the decay envelope. I see three zeros: 10, 30, and 50.
All of these give a period of $$10/0.25 = 30/0.75 = 50/1.25 = 40\ \text{samples}.$$
• So I count the number of samples from the graph and along with the value $1,000$ put the values in second formula in order to find the frequency of the signal. right? May 26 at 13:15
• @MuhammadAhmad Yes, pretty much! Often the period won't be an integer number of samples long. Then you need to do something much more complicated to get the frequency.
– Peter K.
May 26 at 13:19
• check my edit and kindly clarify it May 26 at 13:58 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 10, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8053204417228699, "perplexity": 342.49314979810373}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-27/segments/1656103877410.46/warc/CC-MAIN-20220630183616-20220630213616-00352.warc.gz"} |
http://math.stackexchange.com/questions/10916/can-somebody-explain-the-plate-trick-to-me?answertab=votes | # Can somebody explain the plate trick to me?
I learned of the plate trick via Wikipedia, which states that this is a demonstration of the fact that SU(2) double-covers SO(3). It also offers a link to an animation of the "belt trick" which is apparently equivalent to the plate trick. Since I've thought most about the belt version, I'll phrase my question in terms of the belt trick.
I am not clear on how the plate/belt trick relates to the double covering. Specifically, I am looking for a sort of translation of each step of the belt trick into the Lie group setting. For example, am I correct in interpreting the initial twisting of the belt as corresponding to the action of a point in SU(2)? Which point? Do I have the group right?
-
I thought somebody talked about the plate trick in an answer or a comment on this question, but I don't see it now. Anyway, the answers there are worth looking over. – yasmar Nov 19 '10 at 3:44
@yasmar: Perhaps it was this question you were thinking of. – Rahul Nov 19 '10 at 17:09
@Rahul Thanks. That is the one. – yasmar Nov 19 '10 at 18:13
There is a decent video at youtube.com/watch?v=Rzt_byhgujg – Jeff Mar 18 at 18:36
The diagram in the lower right shows the paths in the space $\operatorname{SO}(3)$ which is the $3$-ball with its antipodal points on its boundary identified. That is why the doubled path appears to be broken; it is passing through antipodal points. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8743342161178589, "perplexity": 314.7934119298375}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-41/segments/1410657129409.8/warc/CC-MAIN-20140914011209-00344-ip-10-196-40-205.us-west-1.compute.internal.warc.gz"} |
https://quant.stackexchange.com/questions/47482/valuation-of-total-return-swaps-trs | # Valuation of Total return swaps (TRS)
I have seen a TRS being valued which has an index as underlying on the asset side. It also has a coupon rate associated with it. Asset leg is calculated by taking
percentage change of asset value from last reset date to valuation date * adjusted notional
The interest accrued is calculated by multiplying
coupon rate * adjusted notional * ((val date-reset date)/360).
The financing leg is calculated by
index on last reset date/100 * LIBOR/100 * ((val date-reset date)/360)
Valuation of TRS is done by subtracting the financing leg from the asset leg if we are long.
Will a coupon rate be always involved in the asset leg? And more importantly why is forward cash flows and discounting not done? Does this methodology of valuation pertain to only this type of TRS?
• A more mathematical description would help tremendously readers to understand what you refer to with the terms "involved", "not done", and which kind of TRS. Mark-to-market valuation of a TRS is done using discounting of forward flows. – jherek Sep 4 '19 at 8:30
• edited the question and added more details – Rejath Johny Sep 4 '19 at 10:08
I think this is the old accrual methodology, historically used for the banking book. I believe it is not market standard anymore and regulators require an MTM (mark-to-market) valuation.
Here is an article that explains the difference between the two. And someone wrote a more mathematical paper, which should help you better understand the accrual valuation (although I don't find the notation great in that paper).
• can you be more specific about the procedure I have described? I need to know more about it – Rejath Johny Sep 4 '19 at 11:59
• That still works for an open TRS (breakable at any time by both parties), breakability is what determines whether to price MTM or accruals – Lliane Sep 5 '19 at 1:05
Will a coupon rate be always involved in the asset leg?
Absolutely. That's what makes it a TRS. The coupon is the price for the return of the asset. Without that coupon the TRS buyer would not receive any return and just be paying interest for no reason.
And more importantly why is forward cash flows and discounting not done? It usually is now! But many TRS trades are breakable by the client, so sometimes this functionality is suspended.
• "Without that coupon the TRS buyer would not receive any return". I am not sure I understood, without the coupon the buyer would still receive/pay the price changes ("price return") on the index, am I rite? – Alex C Sep 4 '19 at 16:31
• Sorry, to be more explicit. The TRS buyer pays interest (usually one of [1m libor, 3m libor, OIS] ) + a spread of some sort . He receives the return of the asset. Without this interest component it's not really a TRS. The definition of a TRS is basically "I pay you interest - you pay me performance". If you vary from that definition it's not really called a TRS. At least not anything that I've traded/seen. – JoshK Sep 4 '19 at 17:57
• My question is, it can be seen that we calculate the percentage return of the index on the asset leg. Then in top of that why is there a coupon again on asset leg. Returns is taken care of when we take the difference in index at valuation and reset dates right? – Rejath Johny Sep 5 '19 at 2:38
• I think you have some confusion in your terminology. It's not a financing leg and an interest leg. They are one and the same thing. You have an interest leg, which accrues the financing and the performance leg, which pays the performance. TRS = "Total Return Swap", so in the performance leg you get any coupon or dividend (subject to tax rules). If you didn't pass on coupon/div it would be a "price return swap", which really doesn't trade. – JoshK Sep 5 '19 at 13:46 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.40871623158454895, "perplexity": 2416.6602024948384}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-05/segments/1579250590107.3/warc/CC-MAIN-20200117180950-20200117204950-00524.warc.gz"} |
https://physics.com.hk/2015/07/ | # Exercise One
Write the function bind.
——————————
bind f' (gx,gs) = (fx, gs++fs) where (fx,fs) = f' gx
The meaning of bind here:
1. apply f' to the last result data gx, generating the new data fx; and
2. concat the last debug string, gs, to the string generating by f', fs.
— [email protected] 10:25 PM
# Problem 14.1a
A First Course in String Theory
14.1 Counting bosonic states
~~~
$n$ is the number of $a$‘s.
$k$ is the number of different $a$‘s.
For $a^{i_1} a^{i_2}$, $n=2$.
(Indices $i_1$ and $i_2$ are not powers. Instead, they are just upper indices for representing different $a$‘s.)
When all $a$‘s commute, $a^1 a^2$ and $a^2 a^1$, for example, represent the same state. So we have to avoid double-counting, except for the same $a$‘s states, such as $a^3 a^3$.
By direct counting, without using the formula, the number of products of the form $a^{i_1} a^{i_2}$ can be built is
$\frac{k(k-1)}{2} + k$
$= \frac{(k + 1)k}{2}$
Let $N(n, k) = {n + k - 1 \choose k - 1}$, the number of ways to put $n$ indistinguishable balls into $k$ boxes.
By using the formula, the number of products of the form $a^{i_1} a^{i_2}$ can be built is
$N(2,k)$
$= \frac{(2+k-1)!}{2!(k-1)!}$
$= \frac{(k+1)k}{2}$
— Me@2015-07-26 08:43:22 AM
# River
You are not a stone flowing on the river.
Instead, a small region of the river is labelled as “you”.
You are a wave of the water.
— [email protected]
# Share
Publish! 7.2
We like to share because we like our information, ideas, and insights to have a future.
— [email protected]
# 避免犯錯 1.2
.
You probably will make those mistakes anyway.
You cannot choose whether to make those mistakes or not.
All you can choose is whether to make those mistakes before or during the exams.
— [email protected]
.
— Me@2018-02-14 09:51:15 PM
.
.
Generalize the bunny invasion example in the list monad chapter for an arbitrary number of generations.
— Wikibooks
——————————
import Control.Monad
generation = replicate 3gen n = foldr (<=<) return (replicate n generation) ---
["bunny"] >>= gen n
m >>= g ≡ join (fmap g m)xs >>= f = concat (map f xs) -- for the List Monad
---
f >=> g= (\x -> f x) >>= g= concat (map g (\x -> f x))
---
xs >>= f >=> gxs >>= (f >=> g)xs >>= ((\x -> f x) >>= g)(xs >>= f) >>= g
xs >>= (return >=> g >=> h)((xs >>= return) >>= g) >>= h
---
xs >>= return= concat (map f xs)= concat (map return xs)= concat (map return ["bunny"])= concat ([return "bunny"])= concat ([["bunny"]])= ["bunny"]
---
-- foldr f acc [] = acc-- foldr f acc (x:xs) = f x (foldr f acc xs)
-- foldr (<=<) return (replicate n generation)
foldr (<=<) return [h,g]= (<=<) h (foldr (<=<) return [g])= (<=<) h ((<=<) g (foldr return []))= (<=<) h ((<=<) g return)= h <=< g <=< return
---
compose :: [b -> [b]] -> b -> [b]compose = foldr (<=<) return
foldr (<=<) return (replicate n generation)= compose (replicate n generation)
— Me@2015-07-08 11:29:40 PM
# Problem 14.1 | Problem 12.11
A First Course in String Theory
14.1 Counting bosonic states
12.11 Counting symmetric products
~~~
$a^{I_1} a^{I_2} ... a^{I_n}$
$i = 1, 2, ..., n$
$I_i = 1, 2, ..., k$
$n$ is the number of $a$‘s.
$k$ is the number of different $a$‘s.
For $k=6$ and $n=9$, one of the possible configurations is
$a^1 a^2 a^2 a^4 a^4 a^4 a^5 a^6 a^6$
The problem is equivalent to that of assigning $n$ balls to $k$ boxes.
Box 1 collects the $a$‘s with index 1.
Box 2 collects the $a$‘s with index 2.
— Me@2015-07-13 03:34:32 PM
# Things You Should Never Do
It’s important to remember that when you start from scratch there is absolutely no reason to believe that you are going to do a better job than you did the first time. First of all, you probably don’t even have the same programming team that worked on version one, so you don’t actually have “more experience”. You’re just going to make most of the old mistakes again, and introduce some new problems that weren’t in the original version.
— Things You Should Never Do, Part I
— Joel Spolsky
2015.07.12 Sunday ACHK
# Passion Test
The Top Idea in Your Mind, 6 | 事業愛情觀 6
.
Am I willing to spend INFINITE time on it?
— Me@2015-07-05 04:26:24 PM
.
Do you want it to be one of your lifelong projects?
— Me@2015-07-12 11:00:11 AM
.
.
# 注定外傳 1.2
（問：但是，有沒有一個可能是，其實，將來所有事情的所有方面，都是注定的。所謂的「將來」，其實和「過去」一樣，都完全是固定的。
（問：為什麼你要講「類似」？
（問：不是呀。在量子力學中，即使有兩組百分百一樣的物理系統，即使它們獲得完全相同的輸入，都可能有不同的輸出。）
— [email protected]
# Euler problem 30
Surprisingly there are only three numbers that can be written as the sum of fourth powers of their digits:
1634 = 1^4 + 6^4 + 3^4 + 4^48208 = 8^4 + 2^4 + 0^4 + 8^49474 = 9^4 + 4^4 + 7^4 + 4^4
As 1 = 1^4 is not a sum it is not included.
The sum of these numbers is 1634 + 8208 + 9474 = 19316.
Find the sum of all the numbers that can be written as the sum of fifth powers of their digits.
——————————
sum_5th_powers n = sum $map ((^5) . digitToInt) (show n) -- sum_5th_powers 999999 == 354294-- sum_5th_powers 9999999 == 413343 For a number having more than 6 digits, the fifth powers of its digits cannot be the number itself. So we should consider only numbers with less than 7 digits. -- sum_5th_powers ______ <= 354294 For the numbers not greater than 354294, the number whose sum_5th_powers can represent the largest number is … When 2 –> 1, in exchange for 4 –> 9, we earn — we get 354199; When 4 –> 3, in exchange for 1 –> 9, we earn — we get 353999; When 5 –> 4, in exchange for 3 –> 9, we earn — we get 349999; When 3 –> 2, in exchange for 4 –> 9, we earn — we get 299999. So the maximum number sum_5th_powers can represent is … -- sum_5th_powers 299999 == 295277 -- 295277-- 199999 -- sum_5th_powers 199999 == 295246 p30 = [n | n <- [10..m], n == sum_5th_powers n] where m = 295246 —————————— — Me@2015-07-06 08:42:07 PM 2015.07.07 Tuesday (c) All rights reserved by ACHK # Quick Calculation 14.8 A First Course in String Theory What sector(s) can be combined with a left-moving NS- to form a consistent closed string sector? ~~~ — This answer is my guess. — What is the meaning of “left-moving NS”? p.322 “Conventionally, the first input in $(\cdot, \cdot)$ is the left-moving sector and the second input is the right-moving sector.” What is the meaning of “+” in “NS+”? p.321 “… we truncate the NS sector to the set of states with $(-1)^F = +1$. The resulting states comprise the so-called NS+ sector.” “The NS+ sector contains the massless states and throw away the tachyonic states.” What is the meaning of “consistent” closed string sector? p.322 “… guarantees that the left and right sectors give identical contributions to the mass-squared:” $\alpha' M_L^2 = \alpha' M_R^2$ If NS+ is the left sector, the corresponding candidate right sectors are NS+, R+, R-. $M$ in NS-sector, Equation (14.37): $M_{NS}^2 = \frac{1}{\alpha'} \left( - \frac{1}{2} + N^\perp \right)$ $M$ in R-sector, Equation (14.53): $M_{Ramond}^2 = \frac{1}{\alpha'} \sum_{n \ge 1} \left( \alpha_{-n}^I \alpha_n^I + n d_{-n}^I d_n^1 \right) = \frac{1}{\alpha'} N^\perp$ Equation (14.78): $\frac{1}{2} \alpha' M^2 = \alpha' M_L^2 + \alpha' M_R^2$ NS+ equations of (14.38): $\alpha'M^2=0,~~N^\perp = \frac{1}{2}:~~~~b_{-1/2}^I |NS \rangle \otimes |p^+, \vec p_T \rangle$, $\alpha'M^2=1,~~N^\perp = \frac{3}{2}:~~~~\{ ... \} |NS \rangle \otimes |p^+, \vec p_T \rangle$, $...$ NS- equations of (14.38): $\alpha'M^2=-\frac{1}{2},~~N^\perp = 0:~~~~\{ ... \} |NS \rangle \otimes |p^+, \vec p_T \rangle$, $\alpha'M^2=\frac{1}{2},~~N^\perp = 1:~~~~\{ ... \} |NS \rangle \otimes |p^+, \vec p_T \rangle$, $...$ Mass levels of R+ and R- (Equations 14.54): $\alpha'M^2=0,~~N^\perp = 0:~~~~|R_a \rangle~~||~~|R_{\bar a} \rangle$ $\alpha'M^2=1,~~N^\perp = 1:~~~~...$ $...$ There are no mass levels in NS+, R+, or R- that can match those in NS-. So NS- can be paired only with NS-: (NS-, NS-) — This answer is my guess. — — Me@2015-07-05 11:09:32 PM 2015.07.05 Sunday (c) All rights reserved by ACHK # Single-world interpretation, 6.2.3 You are still in a superposition after the so-called “collapse”. The unchosen choice is still in the definition of “you”. — Me@2012-04-08 1:21:55 PM 2015.07.03 Friday (c) All rights reserved by ACHK # Intelligence and Wisdom A few days ago I finally figured out something I’ve wondered about for 25 years: the relationship between wisdom and intelligence. Anyone can see they’re not the same by the number of people who are smart, but not very wise. And yet intelligence and wisdom do seem related. How? What is wisdom? I’d say it’s knowing what to do in a lot of situations. I’m not trying to make a deep point here about the true nature of wisdom, just to figure out how we use the word. A wise person is someone who usually knows the right thing to do. If wisdom and intelligence are the average and peaks of the same curve, then they converge as the number of points on the curve decreases. If there’s just one point, they’re identical: the average and maximum are the same. But as the number of points increases, wisdom and intelligence diverge. And historically the number of points on the curve seems to have been increasing: our ability is tested in an ever wider range of situations. The wise are all much alike in their wisdom, but very smart people tend to be smart in distinctive ways. — Is It Worth Being Wise? — Paul Graham 2015.07.03 Friday ACHK # 技巧管理 這段改編自 2010 年 8 月 11 日的對話。 . 有時，你可能收集了，太多重要的讀書技巧，有吃不消的感覺。你可以這樣處理： 第一，你要意識到，讀書技巧夠用就可以。你並沒有必要，學懂或者執行，「所有」的讀書技巧。 第二，你試試每次，只針對一個問題，只執行一個讀書技巧，把它用到最盡為止。例如，我所講的「魔法筆記」技巧，並不只適用於數學科。你在其他科中，亦應大量使用。 到該個技巧自動運作時，你讀書上的下一個問題，自然會浮現出來。那時，你才考慮嘗試，下一個讀書技巧，針對該個新問題。 — [email protected] . . 2015.07.02 Thursday (c) All rights reserved by ACHK # Euler problem 27.2 Haskell —————————— problem_27 = -(2*a-1)*(a^2-a+41) where n = 1000 m = head$ filter (\x -> x^2 - x + 41 > n) [1..] a = m - 1
This is the “official” Haskell solution to Euler problem 27.
This solution is incomprehensible. The following hints are as far as I can get.
Prerequisite considerations:
b must be a prime number, since x^2 + a*x + b must be a prime number when n=0.
a = m - 1 is a choice of the prime number b (in x^2 + a*x + b) just(?) smaller than 1000.
a == 32
(\x -> x^2 – x + 41) 31 == 971
Why not the prime number 997?
— [email protected] 08:53 AM
It is because 997 is not a prime number generated by the formula x^2 - x + 41.
— Me@2015-06-30 11:07:53 AM
map (\x -> x^2 - x + 41) [0..40]
is for generating 41 primes with the greatest Euler’s lucky number 41.
— [email protected] 08:34 AM | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 55, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5094273090362549, "perplexity": 3697.903281022096}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-29/segments/1593655919952.68/warc/CC-MAIN-20200711001811-20200711031811-00091.warc.gz"} |
https://www.physicsforums.com/threads/taylor-polynomial.90602/ | # Taylor Polynomial
• #1
1,444
2
Find the thrid taylor polynomial P3(x) for the function $f(x) = \sqrt{x+1}$ about a=0. Approximate f(0.5) using P3(x) and find actual error
thus Maclaurin series
$$f(x) = f(0) + f'(0)x + \frac{f''(0)}{2} x^2 + \frac{f^{3}(0)}{6} x^3$$
$$f(x) = x + \frac{1}{2} x - \frac{1}{8} x^2 + \frac{3}{48} x^3$$
am i right so far?
To approximate f(0.5) i simply put x=0.5 in the above equation?
How do i fin the actual error, though?
Thank you
Related Introductory Physics Homework Help News on Phys.org
• #2
Tom Mattson
Staff Emeritus
Gold Member
5,500
7
stunner5000pt said:
am i right so far?
All but the first term is right. $f(0)\neq x$
To approximate f(0.5) i simply put x=0.5 in the above equation?
After you fix it, yes.
How do i fin the actual error, though?
Plug x=0.5 into f(x) on a calculator, and subtract your result from it. You won't exactly get the "actual" error because your calculator approximates, too. But it will be a very good estimate.
That depends on what is asked for. The remainder doesn't give you the actual error, but rather the maximum of the actual error. So unless you were asked to put bounds on the error, I would think that you would not have to use the remainder.
• #3
1,444
2
$$f(x) = 1 + \frac{1}{2} x - \frac{1}{8} x^2 + \frac{3}{48} x^3$$
i see the problem, its fixed now
im being cautious so im goingto put hte upper limits
$$R_{4} = \frac{15}{384} (c+1)^{\frac{-7}{2}} x^4$$
so the error must be lesser than or equal to this R4 value. THat c value lies between 0.5 and x?
Is this right?
• #4
1,444
2
is this how one would solve for the maximum possible error as stated in the above post? Please do advise
Thank you for your help and input
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1K | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8069473505020142, "perplexity": 3355.631864365982}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-05/segments/1579250616186.38/warc/CC-MAIN-20200124070934-20200124095934-00078.warc.gz"} |
https://psychometroscar.com/some-probability-and-number-theory/ | Some probability and number theory
(This post was featured in Crikey Math)
When I was doing my undergraduate studies, Number Theory was one of my most favourite courses. I thought I’d go into it but then my interests switched to Probability & Statistics and kind of moved away from the area a little bit. I still dabble in Number Theory from time to time though, which prompts the subject of this post.
My brother (who is a computer engineer) and I were talking about cryptography a few weeks ago and he casually mentioned that, just as a quick-and-easy check, if you have an unknown number that is not divisible by any of the first prime digits (that would be 2, 3, 5, and 7), then there’s a “pretty good chance” that said unknown number is prime. Just to formalize things a little bit, I would like to know what proportion of natural numbers are divisible by 2,3,5 or 7.
Let us start by setting $n\in\mathbb{N}$. We would like to know what is the probability that $n$ is divisible by 2,3,5 or 7. Since 2 divides half of the set of $\mathbb{N}$ we know right from the beginning that the probability is > 0.5.
The least common multiple of 2,3,5 and 7 is 2x3x5x7=210.
We know that 210 has the following list of factors. We build this list by systematically multiplying the numbers 2,3,5,7:
1-element factors: 1, 2, 3, 5, 7
2-element factors: 2×3=6, 2×5=10, 2×7=14, 3×5=15, 3×7=21, 5×7=35
3-element factors: 2x3x5=30, 2x3x7=42, 2x5x7=70, 3x5x7=105
4-element factor: 2x3x5x7=210
Let $S(n)=\{210(n-1)+1, 210(n-1)+2, ..., 210n\}, n=1,2,...$ It is trivial to show $S\subset \mathbb{N}$. And in $S(n)$ there are 210 integers. So by the inclusion-exclusion principle:
$210-(105+70+42+30-35-21-15-14-10-6+7+5+3+2+1)=$ $210-162=48$
Which implies there are 48 of such integers not divisible by 2, 3, 5 or 7.
Overall, it is possible to say then that $\frac{48}{210}=\frac{8}{35}\approx 0.22857$ approximates the proportion of natural numbers that are not a multiple of 2, 3, 5 or 7 as $n$ becomes larger and larger.
By the Prime Number Theorem, we know that $\frac{\pi(x)}{x}\sim \frac{1}{ln(x)}$ where $\frac{\pi(x)}{x}$ is the prime-counting function. So whereas the probability of finding a prime number becomes smaller as $x$ becomes larger, the probability of finding a natural number not divisible by 2, 3, 5 or 7 approaches 0.22857 as $n$ becomes larger and larger.
In general, around 78% of natural numbers are divisible by 2, 3, 5 or 7.
Quick simulation to verify my stuff:
n <- 1:1000000 ##large n, the larger n the closer the true probability n2 <- n%%2 ## %% gives me the division remainder n3 <- n%%3 n5 <- n%%5 n7 <- n%%7
dd <- data.frame(n, n2, n3, n5, n7)
roww <- apply(dd, 1, function(row) all(row !=0 ))
dd1<-dd[roww,]
dim(dd1)[1]/1000000 [1] 0.228571 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 14, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7616086006164551, "perplexity": 471.0345549960511}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-31/segments/1627046151531.67/warc/CC-MAIN-20210724223025-20210725013025-00455.warc.gz"} |
http://www.physicsforums.com/showthread.php?p=3529392 | # Expectation of x^2
P: 2 How to calculate E(x^2) given that x are i.i.d random variables distributed as a standard normal i.e. N(0,1) ? Thank you.
P: 4,572
Quote by James1990 How to calculate E(x^2) given that x are i.i.d random variables distributed as a standard normal i.e. N(0,1) ? Thank you.
Hey James1990 and welcome to the forums.
Do you know the relationship for Variance to second and first order moments?
[HINT: Var(X) = E[X^2] - {E[X]}^2].
What do you know about the mean and variance of your distribution?
Related Discussions Set Theory, Logic, Probability, Statistics 3 Calculus & Beyond Homework 2 Quantum Physics 6 Quantum Physics 1 Quantum Physics 4 | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9403373003005981, "perplexity": 1299.8028145953103}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-23/segments/1405997886087.7/warc/CC-MAIN-20140722025806-00107-ip-10-33-131-23.ec2.internal.warc.gz"} |
https://www.physicsforums.com/threads/fluids-problem.151237/ | # Fluids problem
1. Jan 13, 2007
### kitty9035
1. The problem statement, all variables and given/known data
Water is flowing at 1 m/s in a circular pipe. If the diameter of the pipe decreases to four-ninth its former value, what is the velocity fo the water downstream?
2. Relevant equations
AV=AV
3. The attempt at a solution[/b
(Area1)(Velocity1)=(Area2)(Velocity2)
then...
(A1)(1 m/s)=(4/9)A1(V2) ?
or
A1=(4/9)(V2)
Is that right what would u do next??
2. Jan 13, 2007
### durt
Rewrite the area in terms of its diameter, and then try again.
3. Jan 13, 2007
### AngeloG
Indeed, remember the area for a circle? *circular* being the key word =).
4. Jan 13, 2007
### snowJT
couldn't you just with what your given calculate the volumetric flow rate then, then apply Q = AV to get the velocity in the second pipe.. thats how I would do it
5. Jan 13, 2007
### AngeloG
A1V1 = A2V2, since the density is uniform/incompressible.
You could do as you say, but then you'd have the equation:
A1 * (delta L1) / delta t = A2 * (delta L2) / delta t
A1V1 = A2V2 is a better one to use; well more "simple" one.
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https://ndl.iitkgp.ac.in/document/QzhRVTRiODdmVXZlN0NxdXhLVHVVTUhrWlJOM1Yxa0lOaVZjaFZUOG5Qbz0 | ### Effect of growth rate on crystallization of HfO{sub 2} thin films deposited by RF magnetron sputteringEffect of growth rate on crystallization of HfO{sub 2} thin films deposited by RF magnetron sputtering
Access Restriction
Open
Author Dhanunjaya, M. ♦ Manikanthababu, N. ♦ Pathak, A. P. ♦ Rao, S. V. S. Nageswara Source United States Department of Energy Office of Scientific and Technical Information Content type Text Language English
Learning Resource Type Article Publisher Date 2016-05-23 | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.836539089679718, "perplexity": 17227.868798940173}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-45/segments/1603107876307.21/warc/CC-MAIN-20201021093214-20201021123214-00469.warc.gz"} |
https://rd.springer.com/article/10.1007%2Fs11356-018-4041-4 | Monitoring of odors emitted from stabilized dewatered sludge subjected to aging using proton transfer reaction–mass spectrometry
• Hubert Byliński
• Jacek Gębicki
• Jacek Namieśnik
Open Access
Research Article
Abstract
One of the potential emission sources of odorous compounds from wastewater treatment plants is sludge processing. The odorous compounds released from dewatered sludge can result in odor nuisance. This study concerns the use of flux hood chamber combined with proton transfer reaction—time of flight—mass spectrometry (PTR-MS) technique for periodical monitoring of odorous compounds emitted from aged, stabilized dewatered sludge samples from 2 different wastewater treatment plants located in Pomeranian Voivodeship, Poland. Based on determined concentration of the chemical compounds and olfactory threshold values, theoretical odor concentrations (known also as “odor activity value” or “odor index”) were calculated for 17 selected odorous compounds. As a result, sulfur compounds such as diethyl sulphide, dimethyl sulphide, methanethiol, and ethanethiol were estimated as the most significant chemical compounds responsible for malodorous effect (average results, e.g., methanethiol, 178 ou/m3; diethyl sulphide, 184 ou/m3). Based on Pearson correlation coefficient, we revealed a correlation between odorous substances emitted from aged, stabilized dewatered sludge cakes. It was revealed that stabilized dewatered sludge still possessed significant amount of odorous compounds and applied measurement technique could be used for monitoring of odor concentration level of selected malodorous compounds.
Keywords
Flux hood chamber Odors Proton transfer reaction–mass spectrometry Sludge Wastewater treatment plants
Introduction
Wastewater treatment plants (WWTPs) are one of the significant exemplifications of human activity, which have dominant impact on air quality, especially in the areas close to emission sources (Burlingame et al. 2004; Carrera-Chapela et al. 2014). They are a complex network of technological systems, consisting of many treatment stages, with different process conditions (Xu et al. 2014). Volatile organic compounds emitted from WWTPs, including odorous compounds, can have negative effect on people, animal, and plant ecosystem (Carrera-Chapela et al. 2016a; Gębicki 2016; Byliński et al. 2017b). One of the main sources of odorous compounds emission in WWTPs is sludge processing (Chen et al. 2011; Roy et al. 2011). The presence of VOCs in sludge has been attributed to the degradation of organic material (Adams and Witherspoon 2003). Over 36% of distribution of odor emission from WWTPs is from sludge dewatering, drying, and thickening processes (Gębicki et al. 2016). Among many odorous chemical compounds emitted from sludge cakes, volatile sulfur compounds (VSCs) are commonly considered to be the main substances causing odor nuisance from WWTPs (Carrera-Chapela et al. 2016b; Fisher et al. 2018b). This fact is related to relatively low values of olfactory threshold concentration of these compounds as compared to other volatile compounds (e.g., methanethiol, 0.07 ppb; ethanethiol, 0.0087 ppb as compared to toluene, 457 ppb; benzaldehyde, 42 ppb; or acetonitrile, 13,000 ppb) (Nagata 2003). Emission of VSCs increases with the decrease in sludge oxygenation and increase in temperature during sludge treatment (Mrowiec et al. 2005). Sensory properties of odor mixtures can depend on their chemical composition. Even small modification in composition of the mixture can significantly change their sensory properties (Capelli et al. 2013a).
The products leaving anaerobic digesters, including digestate, which is a stock for dewatered sludge, are a source of odorants emission; it is necessary to process them in a way enabling their further utilization, for example in agriculture (Rosenfeld et al. 2001; Sharma et al. 2017). One of the most frequent operations is stabilization of sludge cakes—the stabilization process reduces organic matter, which leads to putrescibility, the overall microbe level increases, however the amount of pathogenic microbes decreases (Novak et al. 2003). This solution gains increasing popularity due to a possibility of biogas recovery, which is a source of renewable energy (Cieślik and Konieczka 2016). The process of sludge stabilization results in a decrease in the number of environmentally harmful substances, including those causing odor nuisance. Different approaches to the technical solutions in wastewater treatment plants, concerning conditions of the stabilization process, can influence on varying amount of odorous substances present in the sludge after the stabilization process (Qi et al. 2008; Kim et al. 2017). In order to decide about further utilization of stabilized sludge, it is necessary to determine a level of potential emission of the chemical compounds present in the sludge (Byliński et al. 2018). This evaluation can be carried out using mathematical models (Leyris et al. 2005; Lucernoni et al. 2016a) or via field measurements. In the latter case, direct measurements are a frequent solution, which employs devices enclosing investigated surface, which is a source of emission (Lucernoni et al. 2016b). Such approach is often used in the investigations concerning evaluation of wastewater treatments plants or landfills operation as far as analysis of emission level from particular elements of the installation is concerned. One of the advantages of direct measurements is a possibility of qualitative evaluation of emission from particular fragments of the emitting surface (so-called local emission). The direct measurements can provide emission rates from surfaces, rather than ambient emissions, which can be diffuse and difficult to monitor due to the influences of climate (Chen et al. 2017).
The devices used for direct determination of emission level of volatile odorous compounds can differ significantly because of applied construction design, shape, and dimensions of measurement chamber or conditions inside the chamber (Guillot et al. 2014). One of such solutions is flux hood chamber, the application of which to measurement of emission of volatile air pollutants was recommended by the United States Environmental Protection Agency (US EPA) (Klenbusch 1986). Operation of this chamber consists in generation of constant-composition mixture of volatile substances released from the samples under investigation. This is achieved by flushing with a stream of inert gas, for instance high purity nitrogen. Once uniform mixture is obtained, it is possible to sample the analytes using sorption tubes, bags, or other devices for gas samples collection (Hudson et al. 2009). The flux hood chamber is a device commonly used to measure emission of the odorous compounds generated in municipal wastewater treatment plants at particular stages of their operation (Hudson et al. 2008; Parker et al. 2013).
In order to identify and quantify odorous compounds present in gaseous samples, gas chromatography coupled with mass spectrometry (GC-MS) is commonly used (Nicolas et al. 2006; Bruno et al. 2007; Kosek et al. 2018). Typically in gas chromatography methods, a pre-concentration process is achieved by adsorbing volatile compounds from gaseous samples onto a suitable adsorbents. This pre-concentration step and desorption of analytes into the chromatographic column are time-consuming, which significantly elongates procedure (Byliński et al. 2017a; Woźniak et al. 2018). Although gas chromatography is the reference method for the analysis of VOCs in air samples, there is also growing need to develop new methods allowing direct, rapid, not time-consuming, non-invasive, and very sensitive monitoring of volatile compounds present in gaseous samples.
Among various available and investigated methods, there is proton transfer reaction–mass spectrometry technique (PTR-MS). This technique was development in the mid-1990s by Werner Lindinger group and it is based on the chemical ionization (Cappellin et al. 2012; Cui et al. 2016). The PTR-MS technique allows measurement of volatile analytes released directly from the investigated samples, without a need for complex operations of analytes enrichment. It is possible thanks to the fact that the volatile fraction is sucked directly into the ionization chamber. There occurs proton transfer reaction, only for the compounds, which exhibit higher affinity to proton than water. That is why presence of the main air components does not interfere with the results. Unquestionable advantage of the PTR-MS technique is a possibility of analytes measurement at very low concentration level (depending on spectrometer configuration, it is possible to achieve the detection level of ppb or even ppt v/v) (Jordan et al. 2009). PTR-MS technique is widely used in many applications: atmospheric chemistry, plant studies, food science, and medicinal applications (Hewitt et al. 2003; Biasioli et al. 2004; Tani et al. 2007; Blake et al. 2009). To the best of authors’ knowledge, up till now, the PTR-MS technique has not been used for sludge cakes.
The objective for this study was investigation of the capability of proton transfer reaction–mass spectrometry technique for periodical monitoring of concentration of volatile organic compounds emitted from aging anaerobically stabilizated sludge samples. Identification of the volatile organic compounds involved earlier application of the GC-MS technique as well as literature survey (Fisher et al. 2018a, c). This research can show changes in concentration of identified compounds, which can potentially contribute to odor nuisance from stabilized sludge cakes produced in WWTPs. This information can be useful to estimate a potential application of stabilized sludge in agricultural industry or other branches of human activity. Moreover, the PTR-MS technique allows evaluation odor activity values (OAV), describing which odorous compounds have the biggest contribution to strength of perceived odor of the entire gas mixture. Such situation enables optimization of the deodorization methods in order to reduce concentration of these compounds, which have the most significant impact on unpleasant odor generation.
Experimental
Site description and sampling location
Two wastewater treatment plants located in the northern part of Poland were selected for this investigation. Similar as other WWTPs, these facilities consist of three main technological sections: mechanical, biological, and sludge treatment sections. Figure 1 presents general configuration of WWTPs operation. Both processes of sludge stabilization occur in similar technological conditions; however, in the case of WWTP no.2, an additional stage was employed. It involved densification of sludge prior to forwarding them to anaerobic-mesophilic fermentation. Table 1 contains most important information about these treatment plants.
Table 1
Details of wastewater treatment plants employed in the investigation
Location
WWTP no.1
WWTP no.2
Mechanical section
● 4 mechanical screens (two hook-belt screens with 6-mm clearance and two scraper screens with 10-mm clearance)
● 2 sand traps (30 m × 10.4 m × 4.5 m thickness)
● 3 primary settling tanks (diameter ca. 50 m)
● 3 hook screens (6-mm clearance)
● 1 sand trap
● 4 primary settling tanks (diameter ca. 36 m)
Biological section
6 bioreactors (summary 158,100 m3) and secondary settling tanks
A block of biological reactors (summary 104.000 m3) and 8 secondary settling tanks (diameter 42 m)
Sludge treatment
Anaerobic fermentation, temperature 37 °C, retention time 21–28 days
Anaerobic fermentation (36–38 °C, two closed fermentation chambers 5700 m3 each), retention time 15–20 days, external pump mixing
Thermal treatment of sludge
Dewatering of sludge using sedimentation centrifuges; incineration of sludge occurs in a furnace with sand fluidized bed (temp. 850 °C); exhaust gases are subjected to purification processes
Drying of sludge–rotary drum dryer using superheated steam as a drying agent; incineration of dried sludge occurs in a furnace with fluidized bed (temp. 850–900 °C); exhaust gases are subjected to purification processes
Amount of supplied sewage (per day)
92,200 m3
55,000 m3
Amount of waste produce during mechanical treatment (per day)
3 tons
1.5 tons
Amount of solid sludge generated (per day)
140 tons
31 tons
Amount of biogas generated during fermentation (per day)
16,500 m3
9500 m3
Stabilized dewatered sludge series were collected 6 times over a 3-month period. It means 1 series of 3 samples from each plant was collected every month on the same day. On this day, the samples were collected every 20 min. The total of 18 samples from both treatment plants were investigated. Sludge samples were collected in 20 L buckets, sealed with a lid and delivered at ambient temperature for emission analysis in the laboratory of the Gdansk University of Technology. Storage of the sludge cakes was carried out at ambient conditions (laboratory air temperature 20–25 °C).
Instrumentation
Determination of emission of volatile organic compounds from sludge cake samples was possible using Flux Hood Chamber combined with Proton Transfer Reaction Time Of Flight Mass Spectrometer (PTR-TOF-MS). This combination allows direct measurement of volatiles without any sample preparation. Figure 2 presents schematic diagram of flux hood chamber combined with PTR-TOF-MS.
Flux hood chamber
The equipment consists in Plexiglas chamber (dimension 16 in.) with carrier gas inlet and outlet line. On the top of the chamber, there are small holes allowing pressure release.
During the investigation, the sludge samples were placed in buckets, in which they were transported from the treatment plants to a laboratory and stored between successive measurements. After opening the bucket, the sludge sample was enclosed in the flux hood chamber, in the way eliminating air movement between the chamber’s and the bucket’s walls (external wall of the flux hood chamber adhered to internal wall of the bucket). The chamber was mounted in this way during each measurement series. The samples were collected 3 times from every wastewater treatment plant; each time, 3 independent sludge specimens were taken for analysis. The amount of sludge collected was identical in each attempt. Before every measurement series, the sludge sample was stirred in order to ensure uniformity of the emitting surface. Prior to each measurement series, the sludge samples were purged for 30 min with a high purity nitrogen (flow rate 5 L/min, controlled using gas flow meter with no internal rubber parts).
PTR-TOF-MS measurements
Volatile organic compounds were detected in real time using proton transfer reaction—time of flight—mass spectrometry instrument (PTR-TOF-MS 1000 Ultra, Ionicon Analytik GmbH, Innsbruck, Austria). This system allows online measurement of volatile chemical compounds in the range of ppb v/v level. During each analysis, PTR-TOF-MS transfer line (1.2-m long, inner diameter of 1 mm (PEEK tubing, BGB Analytik AG, Switzerland)) was heated to 70 °C. The drift tube was kept under controlled conditions of pressure 2.6 mbar, temperature 70 °C, mass range of m/z = 30 to m/z = 240 Da and voltage 600 V, resulting in a field density ratio (E/N) of 122 Td (E being the electric field strength and N the gas number density; 1 Td = 10−17 Vcm2). In order to record the mass spectra, IonTOF v. 2.4.40 software was used. Data processing was performed with PTR-TOF-MS Viewer v. 3.2.3.0. Tentative identification was performed based on the measured mass, isotopic ratios, and fragmentation spectra. Identified compounds were compared with the literature concerning composition of sludge samples (Fisher et al. 2017a). VOC concentration was calculated from peak areas, according to the formula described in the literature (Lindinger et al. 1998). The reaction rate coefficients used for quantification of analytes were based on the literature (Lindinger et al. 2001; Ammann et al. 2004; Zhao and Zhang 2004; Rinne et al. 2007; Taipale et al. 2008; Cappellin et al. 2012). When no data was available, the rate of kR = 2 × 10−9 cm3/s was used. Limit of quantification was set at 10× standard deviations of the background noise recorded for a blank sample (Konieczka and Namieśnik 2007).
Theoretical odor concentration
High concentration of particular substance present in gaseous samples does not always produce strong odor. One of the parameters, which can inform us about odor characteristic is olfactory threshold value (OTi). Based on OTi values for all quantified substances present in odorous gas mixture and their chemical concentration values, it is possible to estimate odor activity value (OAV) of single odorous compounds (Eq. 1) and sum of theoretical odor concentrations of monitored compounds (Eq. 2):
$$\mathrm{OAV}=\frac{C_{\mathrm{i}}}{{\mathrm{OT}}_{\mathrm{i}}}$$
(1)
$${C}_{\mathrm{od},\mathrm{OT}}=\sum \limits_{i=1}^n\frac{C_{\mathrm{i}}}{{\mathrm{OT}}_{\mathrm{i}}}$$
(2)
where Ci is the analytical concentration of odorous compound i [ppbv], OTi is the olfactory threshold concentration of compound i [ppbv], n is the number of compounds in the odorous mixture, OAV is defined as the odor activity value of single odorous compounds [ou/m3] and Cod,OT is defined as sum of theoretical odor concentrations of monitored compounds [ou/m3]. Based on the ratios between measured concentrations and olfactory threshold concentrations, a simple estimation of relative contribution of odor of sludge samples, in the absence of sensory measuring techniques, can be used. It must be emphasized that the theoretical odor concentration of mixture can differ from the value of odor concentration determined with dynamic olfactometry, for instance, due to presence of odor interaction effects (Byliński et al. 2017b).
Specific odor emission rates
Application of the flux hood chamber for measurement of emission of volatile odorous compounds, generated due to aging of sludge cakes, allows determination of a parameter known as specific odor emission rate (SOER). According to a definition, value of this parameter is a function of flow rate of the gas introduced to the measurement chamber, surface area of sludge being a source of emission and odor concentration determined for the investigated compounds (Capelli et al. 2013b). In the case of performed investigations, odor concentrations were not determined using dynamic olfactometry technique, commonly applied in this type of research. The values of odor concentration, adapted to calculation of SOER parameter, were determined instrumentally (see “Theoretical odor concentration” section), which is an alternative to the olfactometric approach and contributes to shortening of the time necessary for result acquisition. The values of SOER parameter, determined using theoretical odor concentrations of mixture, were calculated using the following equation (Eq. 3):
$$\mathrm{SOER}=\frac{C_{\mathrm{od},\mathrm{OT}}\times {Q}_{\mathrm{N}}}{A}$$
(3)
where SOER, specific odor emission rate [ou/m2s]; Cod,OT, sum of theoretical odor concentrations of monitored compounds [ou/m3]; QN, flow rate of nitrogen into chamber [m3/s]; and A, surface area enclosed by the chamber [m2].
Statistical analysis
Statistical analysis was carried out using SPSS Statistics software (Version 21.0, SPSS Inc., Chicago, Illinois, USA). Analysis of correlation was conducted in order to determine dependences between concentration of particular compounds emitted from stabilized sludge cakes. Determined correlations were meant to pertain to all monitored compounds as well as to particular groups of chemical compounds. Special attention was paid to the correlations occurring in case of both samples of sludge cakes. The values of Pearson correlation coefficient were determined for significance levels 95% and 99%.
Results and discussion
Concentration of VOCs emitted from sludge
The chemical concentrations of 17 volatile compounds emitted from aged, stabilized sludge samples from two different wastewater treatment plants are shown in Table 2.
Table 2
Average concentrations of tentatively identified compounds emitted from stabilized sludge cakes (SD standard deviations)
Tentatively identified compounds, protonated molecular formula, and protonated mass (amu)
Concentration (ppbv) ± SD
WWTP no.1
WWTP no. 2
1st day
7th day
10th day
14th day
21st day
1st day
7th day
10th day
14th day
21st day
Diethyl sulphide (DES) (C4H10S)H+ (91.0576)
1.84 ± 0.09
1.43 ± 0.22
1.02 ± 0.31
1.01 ± 0.04
0.75 ± 0.04
6.08 ± 0.15
2.83 ± 0.88
2.24 ± 0.18
2.02 ± 0.27
1.95 ± 0.17
Dimethyl sulphide (DMS) (C2H6S)H+ (63.0263)
18.67 ± 0.82
10.10 ± 0.90
11.07 ± 1.13
12.60 ± 1.13
2.43 ± 0.07
10.57 ± 9.43
12.20 ± 1.23
6.35 ± 3.81
5.23 ± 5.08
3.53 ± 1.08
Ethanethiol (ETH) (C2H6S)H+ (63.0263)
0.44 ± 0.07
0.20 ± 0.01
0.21 ± 0.02
0.29 ± 0.02
0.24 ± 0.07
0.82 ± 0.10
0.31 ± 0.03
0.25 ± 0.04
0.21 ± 0.03
0.20 ± 0.06
Methanethiol (MTH) (CH4S)H+ (49.0107)
10.12 ± 0.31
4.15 ± 0.18
3.4 ± 0.21
3.05 ± 0.06
2.95 ± 0.15
12.43 ± 0.53
4.88 ± 0.74
4.55 ± 0.82
3.58 ± 0.65
2.91 ± 0.22
Acetonitrile (ACN) (C2H3N)H+ (42.0338)
12.59 ± 0.76
12.09 ± 0.84
11.66 ± 0.83
10.82 ± 0.34
5.60 ± 0.19
5.46 ± 0.21
7.92 ± 0.10
6.65 ± 0.20
11.96 ± 1.06
13.17 ± 1.50
Pyridine (PIR) (C5H5N)H+ (80.0495)
1.35 ± 0.04
1.33 ± 0.40
2.81 ± 1.38
0.47 ± 0.11
1.39 ± 0.02
2.91 ± 0.21
0.53 ± 0.10
0.31 ± 0.04
0.42 ± 0.08
0.75 ± 0.28
Benzene (BEN) (C6H6)H+ (79.0542)
3.69 ± 0.34
3.57 ± 0.19
2.97 ± 0.35
1.69 ± 0.06
0.93 ± 0.12
10.48 ± 5.36
4.67 ± 0.70
2.13 ± 0.16
2.28 ± 0.16
3.13 ± 0.45
Toluene (TOL) (C7H8)H+ (93.0699)
4.46 ± 0.32
2.99 ± 0.22
2.62 ± 0.55
1.57 ± 0.07
0.92 ± 0.08
26.35 ± 0.50
11.86 ± 0.94
13.35 ± 2.23
20.77 ± 1.80
24.96 ± 3.78
Xylene* (XYL) (C8H10)H+ (107.0855)
7.37 ± 0.48
15.18 ± 0.47
14.56 ± 2.04
7.98 ± 0.20
1.72 ± 0.15
5.29 ± 0.11
4.29 ± 0.51
4.69 ± 0.37
5.51 ± 0.50
5.61 ± 0.67
Cymene* (CYM) (C10H14)H+ (135.1168)
3.29 ± 0.14
2.37 ± 0.20
2.06 ± 0.35
1.82 ± 0.13
0.94 ± 0.03
6.14 ± 0.12
7.65 ± 0.83
4.84 ± 0.26
10.78 ± 1.30
10.38 ± 1.84
1,2,3-trimethylbenzene (TMB) (C9H12)H+ (121.1012)
4.50 ± 0.18
3.38 ± 0.24
3.03 ± 0.47
2.02 ± 0.12
1.08 ± 0.07
5.08 ± 0.08
5.25 ± 0.60
3.95 ± 0.22
7.00 ± 0.71
7.06 ± 1.02
1-propanol (PRO) (C3H8O)H+ (61.0648)
34.94 ± 2.96
17.55 ± 0.90
11.05 ± 1.52
6.67 ± 0.39
5.25 ± 1.04
27.09 ± 1.24
23.52 ± 3.49
12.97 ± 1.07
12.56 ± 1.99
21.64 ± 4.75
Ethanol (ETN) (C2H6O)H+ (47.0491)
10.64 ± 0.18
13.86 ± 0.39
11.83 ± 1.46
10.48 ± 6.57
12.12 ± 1.33
22.19 ± 1.66
21.49 ± 1.78
18.68 ± 0.83
16.53 ± 1.24
22.29 ± 2.24
Acetaldehyde (ACA) (C2H4O)H+ (46.0413)
7.87 ± 0.67
7.20 ± 0.90
7.76 ± 0.57
9.58 ± 1.09
6.23 ± 0.57
27.21 ± 0.94
18.75 ± 2.24
15.83 ± 0.52
19.98 ± 1.04
23.08 ± 1.72
Benzaldehyde (BZA) (C7H6O)H+ (107.0491)
6.54 ± 0.38
13.81 ± 0.59
13.33 ± 1.10
7.09 ± 0.50
1.52 ± 0.19
4.80 ± 0.19
3.78 ± 0.50
4.08 ± 0.38
4.84 ± 0.60
5.27 ± 0.71
Acetone (ACT) (C3H6O)H+ (59.0491)
23.51 ± 1.50
9.93 ± 1.83
8.41 ± 1.05
6.12 ± 0.77
5.52 ± 0.74
37.91 ± 2.15
33.82 ± 2.64
27.72 ± 3.46
23.30 ± 1.38
33.89 ± 1.39
α-pinene (PIN) (C10H16)H+ (137.1325)
13.92 ± 0.67
7.65 ± 0.76
5.39 ± 0.83
3.01 ± 0.11
2.29 ± 0.13
14.05 ± 0.25
20.88 ± 1.47
13.93 ± 0.80
33.27 ± 2.91
33.13 ± 2.05
*Mixture of isomers of these compounds
Chemical compounds present in this table were selected as the main odorous compounds emitted from sludge cakes based on the available literature (Rosenfeld et al. 2001; Fisher et al. 2017a, b) and quantitative analysis of sludge samples using thermal desorption-gas chromatography coupled with mass spectrometry technique.
Composition of volatile fraction from flux hoods headspace of the sludge cakes was changing significantly during execution of the investigation. The highest concentrations, determined during the measurements conducted on the day of sludge collection from the treatment plant, were observed for:
• the sludge sample from the treatment plant no. 1 for dimethyl sulphide, 1-propanol, and acetone; they were at the level of 18–35 ppbv,
• the sludge sample from the treatment plant no. 2 for dimethyl sulphide, acetone, benzene, toluene, 1-propanol, and acetaldehyde; they were at the level of 26–40 ppbv.
In case of the sludge sample from the treatment plant no. 2, the concentrations were significantly higher for most of the monitored compounds. For example, 14 out of 17 compounds exhibited higher concentration on the first day of measurements. It was observed that concentration of some compounds decreased during the entire 21-day measurement cycle. The examples are 1-propanol and cymene for the sludge from the treatment plant no. 1 or ethanethiol and diethyl sulphide for the sludge from the treatment plant no. 2. In the other cases, it was noticed that on the seventh day since the sample collection concentration of a given compound was substantially lower than on the first day of measurements, however, the differences in concentration between the seventh and twenty-first day were not so significant (for instance acetone, methanethiol for sludge from the treatment plant no. 1 or benzene and methanethiol for the sludge from the treatment plant no. 2). In the case of some compounds, the concentrations underwent small fluctuations throughout the period of investigation (for example acetaldehyde and ethanethiol for the sludge from the treatment plant no. 1 or benzaldehyde for the sludge from the treatment plant no. 2).
Composition of volatile fraction of stabilized sludge cakes subjected to aging can differ depending on the origin of particular sludge sample. Both treatment plants also differ in selected technological parameters (see Table 1), for instance, time of sludge retention at the anaerobic stabilization stage (Lewkowska et al. 2016). Site planning around the plant can play an important role in composition of sludge. In heavy industrialized regions with the facilities lacking wastewater treatment plants, composition of wastewater can be especially rich in the compounds characteristic for an operation profile of particular facility (Fisher et al. 2017b). In the case of dominant contribution of households or residential areas, a profile of wastewater supplied to a treatment plant will be completely different (Alvarez et al. 1999). It should be emphasized that the PTR-MS technique allowed identification and measurement of ethanethiol and methanethiol, the compounds which are easily converted to sulphides upon measurements with other methods (Gruchlik et al. 2013)
Theoretical odor concentration
Tentatively identified compounds present in Table 2 can have different impact on odor nuisance associated with treatment of sludge cakes. These compounds have different odor properties, which also depend on composition of odorous mixture and some external factors (air temperature and humidity, intensity of solar radiation). In order to define which of these compounds have most significant impact on unpleasant smell, odor activity value for each compound (OAV) and sum of theoretical odor concentrations of monitored compounds (Cod,OT) were calculated. In Table 3, an example of calculation of OAV and Cod,OT was shown. In Fig. 3, a summary of Cod, OT was compared taking into account type of WWTP and measurement day.
Table 3
Example of calculation of OAV (sludge sample from WWTP no 2. at 1st day of storage).* olfactory threshold was calculated as average of olfactory threshold for 3 isomers of this compound
Name of compound
Odor description
OTi [ppbv] (Nagata 2003)
OAV [ou/m3]
Minimum
Maximum
Average
Diethyl sulphide
Sulfurous, onion, leek,
0.033
179.7
188.8
184.2
Methanethiol
Cheese, cooked cabbage, fishy, garlic, gasoline, meaty, rotten egg, sulfurous
0.07
170.1
185.1
177.6
Ethanethiol
Garlic-like, skunk-like, strong
0.0087
82.5
105.0
93.8
Acetaldehyde
Ethereal, fresh, fruity, pungent
1.5
17.5
18.8
18.1
Dimethyl sulphide
Cabbage, fruity, gaseous, gasoline, moldy, sulfurous, vegetable soup
3
13.5
14.2
13.9
Acetone
Characteristic, sweetish, fragrant
42,000
< 1
Acetonitrile
Aromatic, characteristic, sweet, ethereal
13,000
< 1
Cymene
Balsamic, citrus, fruity, fuel gasoline, herbaceous, lemon, solvent, spicy, sweet
7165*
< 1
Benzene
Paint thinner
2700
< 1
Ethanol
Alcoholic, pungent, sweet
520
< 1
Toluene
Caramelized, ethereal, fruity, paint, pungent, rubber, solvent,
457
< 1
Xylene
cold meat fat, plastic
380*
< 1
α-pinene
Camphor, citrus, fruity, green, lime, pine, sweet, terpenic, turpentine, woody
180
< 1
1,2,3-trimethylbenzene
Characteristic, distinctive, aromatic
120
< 1
1-propanol
Alcoholic, fruity, musty, plastic, pungent
94
< 1
Pyridine
Cold meat fat, fishy, rancid
63
< 1
Benzaldehyde
Almond, burnt sugar, fruity, woody
42
< 1
C od,OT
463.9
512.6
488.3
Based on the results presented in Table 3 and Fig. 3, it can be observed that strength of perceived odor differed for both samples, although this difference diminished with time as far as given measurement day is concerned. The highest values of sum of theoretical odor concentrations of monitored compounds were determined on the day of the samples collection from the plants. Storage and aging of the sludge resulted in a decrease in odor concentrations. It can also be noticed that the rate of sum of theoretical odor concentrations of monitored compounds decrease diminished after 10 days and stabilized as far as the samples collected from wastewater treatment plant are concerned. However, obtained values were still at the level of 100 ou/m3, which means significant exceeding of the admissible levels accepted in many countries with strict policy regarding emission of odorous compounds (Bokowa 2010; Van Harreveld et al. 2013; Guillot and Milan 2016).
Comparison of the sum of theoretical odor concentrations of monitored compounds reveals that in case of every measurement day, Cod,OT values of the sludge collected from the treatment plant no. 2 were higher than the one determined for the sludge from the treatment plant no. 1. Such situation can suggest two dominant technological issues. Firstly, the wastewater treatment plant no. 1 processes bigger amount of wastewater, which leads to dilution of the entire contaminants load, thus to dilution of the odorous compounds. Secondly, duration of anaerobic fermentation in a technological process of the treatment plant no. 1 is longer, which allows transfer of bigger amount of volatile organosulphur compounds and volatile organic compounds to biogas. The data presented in Table 3, concerning the values of olfactory threshold of particular odorants and OAV determined for them, suggest that organosulphur compounds (methanethiol, ethanethiol, methyl sulphide, diethyl sulphide) had the biggest influence on summary odor concentration. These compounds are characterized by relatively low values of olfactory threshold, which implies that they can have a dominant impact on strength of perceived odor, even if they are present at low concentration level. Figure 4 illustrates changes of OAV for four aforementioned compounds during the entire period of the investigation. Analysis of these data reveals that methanethiol (in case of the treatment plants no. 1 and no. 2) and diethyl sulphide (in case of the treatment plants no. 2) exhibited the biggest influence on the level of perceived odor.
Emission from sludge cakes
The information concerning concentration changes of particular compounds due to aging of stabilized sludge cakes and corresponding OAV odor concentrations constitutes valuable data reflecting possible changes of odor character of sludge cakes. Defining of potential influence of odorants released to the environment should also take into account the factors connected with the rate of release and propagation of the odorants.
In order to determine emission level of volatile odorous compounds, two equipment solutions are most commonly employed–flux chamber, utilized in the investigations described in this paper, and wind tunnel system. Fundamental difference between these two devices is connected with geometrical parameters and internal circulation of the gas flushing an odorant-emitting surface. Application of these solutions allows evaluation of odorants emission level defined as SOER. Table 4 gathers the values of SOER parameter obtained for the samples of sludge cakes during the investigation of odorous compounds emission as well as some literature examples determined for different potential sources of odorous compounds emission, taking into account type of the chamber used for odorants emission measurement.
Table 4
Specific odor emission rates for sludge samples and other literature examples
SOER [ou/m2s] Days of storage: 1st 7th 10th 14th 21st Stabilized biosolids samples WWTP no. 1 0.157 ÷ 0.180 0.078 ÷ 0.094 0.062 ÷ 0.082 0.072 ÷ 0.079 0.056 ÷ 0.069 WWTP no. 2 0.297 ÷ 0.328 0.102 ÷ 0.165 0.099 ÷ 0.125 0.073 ÷ 0.122 0.058 ÷ 0.121 Literature examples Sources of emission Type of chamber SOER [ouE/m2s] ref. Municipal solid waste landfills Wind tunnel 2.1 ÷ 8.9 (Sironi et al. 2005) “LabOlf” sampling device (homemade) 0.011 (Lucernoni et al. 2016b) Agricultural odor sources Flux hood chamber 0.194 ÷ 1.973 (Hudson et al. 2009) Wind tunnel 13.47 ÷ 229.0 Livestock facilities Wind tunnel Polypropylene cover 1.3 ÷ 2.1 (Hudson et al. 2006, 2008) 12.2 ÷ 57.0 Wind tunnel Straw cover 0.5 ÷ 4.6 3.3 ÷ 39.7
Based on the emission of odorous compounds illustrated in Table 4, it can be stated that higher values were obtained for the sludge originating from the treatment plant no. 2, which is a consequence of higher values of OAV identified in the samples collected from this plant. Analogously, it was observed the value of SOER parameter also decreased upon aging of the samples.
Evaluation of emission of the odorous compounds released from different industrial and municipal sources can be an indicator of environmental impact of particular facility (Wu et al. 2017). Different values of odorous compounds emission can be obtained depending on type of odorants emission sources, methodology of investigation, and design solutions applied (geometrical dimensions, type of utilized material, circulation of gas stream inside the chamber)—selected examples are presented in Table 4. The information presented shows that magnitude of the SOER parameter is strongly diversified, both within single emission source as well as type of measurement chamber. In majority of cases, literature values are higher than these calculated for sludge cake samples. This difference can stem from a couple of factors. In the case of literature data, odorant emission level was calculated based on the odor concentrations evaluated using dynamic olfactometry technique, being a reference method in olfactometric investigations. In our studies, OAV were determined only on the basis of concentrations of particular compounds and their olfactory thresholds, which could have influenced on lower values of odor concentrations and thus on lower values of odorants emission. Instrumental investigations do not take into consideration the effect of odor interactions (for example odor synergism), but only sum of odor concentrations of particular compounds (Gębicki 2016). Moreover, the investigation engulfed only 17 odorous compounds, whereas holistic examination using dynamic olfactometry does not impose any limitation as far as the number of compounds in odorous mixture is concerned. Furthermore, in many cases, odorants emission level is determined with respect to “in situ” process, not to the material obtained as a product of selected unit process (Byliński et al. 2017a). Prior to the measurements, the sludge samples were transported to a laboratory, which could also have an influence on lower concentration of odorants determined during the analyses.
Statistical analysis
In order to describe mutual dependences between concentrations of particular compounds present in volatile fraction of stabilized sludge cakes, the numerical values of Pearson correlation coefficient were determined and included in Table 5, together with the concentration values obtained for both treatment plants. These data indicate strong, positive correlations between some compounds belonging to the same class of chemical compounds, especially organosulphur compounds:
• Methanethiol revealed strong, positive correlation with ethanetiol and diethyl sulphide (in case of the sludge from the treatment plant no. 1 r2I = 0.993, r2I = 0.896, respectively, in case of the sludge from the treatment plant no. 2 r2II = 0.996, r2II = 0.994) and dimethyl sulphide with diethyl sulphide (r2I = 0.827, r2II = 1000).
• Strong, positive correlation was noticed between dimethyl sulphide and ethanethiol and methanethiol (in case of the sludge from the treatment plant no. 2 r2II = 0.998 and r2II = 0.994, respectively, however r2I = 0.723, r2I = 0.765).
Table 5
Pearson correlation coefficients between different odorous compounds emitted from sludge cakes (n = 5, 1st line concerns WWTP no. 1 and 2nd line, WWTP no. 2)
ACN
ACA
MTH
ACT
PRO
ETH
BEN
TOL
BZA
PIN
TMB
ETN
XYL
CYM
DMS
PIR
DES
ACN
1
.534
.490
.558
.627
.292
.881*
.802
.746
.669
.868
.049
.756
.872
.863
.120
.747
− .030
− .734
− .310
− .294
− .688
− .600
.281
.600
.981**
.904*
− .205
.590
.931*
− .689
− .504
− .691
ACA
1
.039
.040
.009
.294
.079
.100
.195
.011
.168
.832
.208
.298
.610
− .397
.137
.684
.927*
.745
.737
.809
.884*
.654
.038
.330
.575
.584
.170
.731
.874
.734
MTH
1
.995**
.968**
.883 *
.631
.871
− .084
.950*
.808
− .349
− .075
.850
.765
− .051
.896 *
.862
.631
.996 **
.982**
.407
.025
− .658
− .403
.409
.014
− .528
.994 **
.949*
.994 *
ACT
1
.985**
.840
.704
.916*
.016
.974**
.862
− .385
.024
.890*
.790
.020
.921*
.617
.886*
.935*
.814
.527
− .247
.042
.428
.502
− .126
.872
.967**
.874
PRO
1
.753
.796
.955*
.141
.997**
.913*
− .417
.150
.926*
.784
.026
.968**
.686
.698
.385
.101
− .244
− .009
.905*
− .046
− .109
.699
.725
.705
ETH
1
.269
.597
− .402
.711
.527
.027
− .390
.642
.723
− .329
.672
.993**
.455
.073
− .610
− .344
.464
.050
− .474
.998 **
.969**
.999 **
BEN
1
.928*
.710
.837
.959**
− .405
.716
.903*
.721
.312
.858
.559
.193
− .524
− .245
.481
.165
− .387
.988**
.991**
.990**
TOL
1
.415
.974**
.992**
− .407
.423
.977**
.838
.199
.955*
.920*
.308
.537
.296
.889 *
.377
.432
.654
.436
BZA
1
.213
.518
− .118
1.000 **
.421
.317
.457
.284
.591
.727
.107
.979**
.604
.046
.308
.051
PIN
1
.939 *
− .437
.221
.942 *
.792
.082
.971**
.954 *
− .238
.597
.982 **
− .603
− .436
− .609
TMB
1
− .351
.526
.981**
.854
.213
.938*
− .079
.720
.983**
− .336
− .148
− .343
ETN
1
− .108
− .202
.123
− .670
− .277
− .083
− .173
.462
.529
.478
XYL
1
.432
.331
.445
.295
.607
.024
.267
.025
CYM
1
.924*
.048
.962**
− .460
− .302
− .469
DMS
1
− .082
.827
.961**
1.000 **
PIR
1
− .086
.964**
DES
1
Italicized entries show the strongest correlation between chemical compounds
ACN acetonitrile, ACA acetaldehyde, MTH methanethiol, ACT acetone, PRO 1-propanol, ETH ethanethiol, BEN benzene, TOL toluene, BZA benzaldehyde, PIN α-pinene, TMB 1,2,3-trimethylbenzene, ETN ethanol, XYL xylene, CYM cymene, DMS dimethyl sulphide, PIR pyridine, DES sulphide diethyl
*P < 0.05 (2-tailed)
**P < 0.01 (2-tailed)
Obtained information about high values of correlation coefficients indicates similar character of concentration changes of particular substances from the organosulphur compounds group due to sludge aging. Similar dependence was also observed in case of the investigations concerning emission of odorous compounds from 9 different regions of a landfill (Fang et al. 2012). A strong correlation within investigated groups of compounds, also including organosulphur ones, was observed based on analysis of linearity of identified compounds behavior. Additionally, a correlation between the investigated groups of compounds was evident, which could be a result of transformations of particular groups of compounds into the other ones.
In the case of aromatic hydrocarbons, a positive correlation was observed for both sludge samples, but only between a mixture of xylenes and benzaldehyde (r2I = 1000 and r2II = 0.979). For the remaining groups of compounds, only single, strong correlations were noticed between concentrations of the compounds belonging to the same chemical group. That is why, it is difficult to state, based on the investigations presented in this paper, that changes of concentration of the compounds, except of organosulphur ones, are correlated in a linear way. Obviously, one has to remember about small number of the investigated compounds, however they play an important role from the point of view of odor nuisance associated with processing of sludge cakes.
Conclusions
The paper presents the attempt to apply the flux hood chamber coupled with proton transfer reaction–mass spectrometry technique for periodical monitoring of concentration changes of selected odorous compounds released during aging of stabilized and dewatered sludge cakes originating from two wastewater treatment plants. Combination of these solutions allowed determination of concentration changes of 17 odorous compounds released from the sludge cakes. Based on literature values of olfactory thresholds of the investigated compounds, it was revealed that organosulphur compounds (independently on the progress of sludge aging) had the biggest contribution to an increase in odor intensity connected with sludge cakes processing, in spite of the fact that their concentrations are lower than the ones of the other substances emitted from the sludge cakes. It was shown that even after 21 days of sludge aging, the sum of theoretical odor concentrations of monitored compounds still possessed significant load of odorous contaminants; the level of evaluated concentration was ca. 100 ou/m3. Moreover, it was found, comparing obtained results with literature data, that the results acquired with various types of chambers for measurement of volatile odorous compounds emission can differ between each other. These differences can result from flow rate of gas supplied to the chamber or construction design of the chamber, for example, implementation of internal mixing. It was also shown that in the case of organosulphur compounds, one could see correlations between concentrations of particular compounds belonging to this group.
Presented methodology of measurement of volatile odorous compounds employing the flux hood chamber coupled with PTR-TOF-MS technique allows monitoring of concentration of these compounds in real time. It enables collection of big amount of data without a need of time-consuming and expensive operations connected with preparation for analysis. So far, the PTR-MS technique has not been employed to monitoring of dewatered sludge. As compared to the GC-MS technique with thermal desorption, it is characterized by significantly shorter time of a single analysis and no need for sample preparation prior to analysis, which is in accordance with the green chemistry principles. Moreover, it excludes application of various types of sorbents for analytes sampling, which obviously influences on the final results of quantitative measurements (elimination of additional measurement errors). It seems that among other instrumental techniques, the PTR-MS can be one of the most effective approaches to real-time monitoring of concentration changes of particular odorous compounds. Nevertheless, it must be emphasized that dynamic olfactometry technique is the reference method, which provides holistic measurement of the entire mixture, not of its particular components, and takes into account odor interactions, for example, synergism.
The relatively high OAV of organosulfur compounds emitted from the sludge cakes cause an issue with the further utilization of the stabilized sludge. One could assume that after the unit processes depicted in Fig. 1, the content of these compounds ought to be characterized by significantly lower values of OAV. However, since their thermal utilization leads to the further emission of pollutants into the atmosphere in the form of sulfur dioxide, the improvement of the methane fermentation process through the disintegration of concentrated sludge seems to be a valid approach. The optimization of the parameters of these unit operations will result in a lower concentration of organosulfur compounds in the stabilized sludge, thus reducing the emission of odors.
Notes
Acknowledgements
The investigations were financially supported by the Grant No. UMO-2015/19/B/ST4/02722 from the National Science Centre and by a Marie Curie International Outgoing Fellowship (PIOF-GA-2013-622523 OdourCOB) within the seventh European Community Framework Programme.
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http://www.archive.org/stream/reportofcongress23unit/reportofcongress23unit_djvu.txt | # Full text of "Report of the congressional committees investigating the Iran- Contra Affair : with supplemental, minority, and additional views"
## See other formats
Y l.l/2:SeriaI 13764
United States Congressional...
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100th Congress — 1st Session • January 6-December 22, 1987
Senate Report
No. 216
IRAN-CONTRA INVESTIGATION
APPENDIX B, VOLUME 23
DEPOSITIONS
United States Congressional Serial Set
Serial Number 13764
United States Government Printing OfTice
Washington : 1989
Union Calendar No. 277
100th Congress, 1st Session
S. Rept. No. 100-216 H. Rept. No. 100-433
Report of the Congressional Committees Investigating the
Iran-Contm Affair
Appendix B: Volume 23
Depositions
Daniel K. Inouye, Chairman,
Senate Select Committee
Lee H. Hamilton, Chairman,
House Select Committee
U.S. Senate Select Committee U.S. House of Representatives
On Secret Military Assistance to Iran Select Committee to Investigate
And the Nicaraguan Opposition Covert Arms Transactions with Iran
November 13, 1987. -Committed to the Committee of the Whole House
on the State of the Union and ordered to be printed.
November 17, 1987. -Ordered to be printed.
Washington : 1988
Bnittd States Senate
SELECT COMMITTEE ON SECRET MILITARY
ASSISTANCE TO IRAN AND THE NICARAGUAN OPPOSITION
WASHINGTON, DC 20510-6480
March 1, 1988
Honorable John C. Stennis
President pro tempore
United States Senate
Washington, D.C.
Dear Mr. President:
We have the pleasure to transmit herewith, pursuant to
Senate Resolution 23, Appendix B to the final Report of the
Senate Select Committee on Secret Military Assistance to Iran
and the Nicaraguan Opposition. We will submit such other volumes
of Appendices to the Report as are authorized and as they become
available.
Sincerely,
iLA\\AJu. U Utut^
vice Chairman
III
U.S. HOUSE OF REPRESENTATIVES
SELECT COMMITTEE TO INVESTIGATE
COVERT ARMS TRANSACTIONS WITH IRAN
UNITED STATES CAPITOL
WASHINGTON. DC 20515
(202) 225-7902
198£
The Honorable Jim Wright
Speaker of the House
U. S. Capitol
Washington, D. C. 20515
Dear Mr. Speaker:
Pursuant to the provisions of House Resolutions 12 and
330 and House Concurrent Resolution 195, 100th Congress, 1st
Session, I transmit herewith Appendix B to the R eport of the
Congressional Committees Investigating the Iran-Contra Affair ,
House Report No. 100-433, 100th Congress, 1st Session.
Appendix B consists of the depositions taken by the
Select Committees during the investigation. The contents of
Appendix B have been declassified fop-Yslease to the public.
United States Senate
Select Committee on Secret Military Assistance
To Iran and the Nicaraguan Opposition
Daniel K. Inouye, Hawaii, Chairman
Warren Rudman, New Hampshire, Vice Chairman
George J. Mitchell, Maine
Sam Nunn, Georgia
Paul S. Sarbanes, Maryland
Howell T. Heflin, Alabama
David L. Boren, Oklahoma
James A. McClure, Idaho
Orrin G. Hatch, Utah
William S. Cohen, Maine
Paul S. Trible, Jr., Virginia
Arthur L. Liman
Chief Counsel
Executive Assistant Deputy Chief Counsel
To the Chief Counsel
Mary Jane Checchi
Executive Director
Lance I. Morgan
Press Officer
VI
United States House of Representatives
Select Committee to Investigate Covert Arms
Transactions with Iran
Lee H. Hamilton, Indiana, Chairman
Dante B. Fascell, Florida, Vice Chairman
Thomas S. Foley, Washington
Peter W. Rodino, Jr., New Jersey
Jack Brooks, Texas
Louis Stokes, Ohio
Les Aspin, Wisconsin
Edward P. Boland, Massachusetts
Ed Jenkins, Georgia
Dick Cheney, Wyoming, Ranking Republican
Wm. S. Broomfield, Michigan
Henry J. Hyde, Illinois
Jim Courter, New Jersey
Bill McCollum, Florida
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John W. Nields, Jr.
Chief Counsel
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Deputy Chief Counsel
Kevin C. Miller
Staff Director
Thomas R. Smeeton
Minority Staff Director
George W. Van Cleve
Chief Minority Counsel
Richard J. Leon
Deputy Chief Minority Counsel
VII
United States Senate
Select Committee on Secret Military Assistance to
Iran and the Nicaraguan Opposition
Arthur L. Liman
Chief Counsel
Executive Assistant Deputy Chief Counsel
to the Chief Counsel
Mary Jane Checchi
Executive Director
Lance I. Morgan
Press Officer
Associate Counsels
C. H. Albright, Jr.
Daniel Finn
C. H. Holmes
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Embrey, Sr.
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Samuel Hirsch
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John C. Martin
Melinda Suddes*
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Marshall
Georgiana
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Kim Lasater
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Manwarring
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Smallwood*
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Kathryn A. Momot
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VIII
Committee Members' Designated Liaison
Senator Inouye
Senator Rudman
Senator Mitchell
Senator Nunn
Senator Sarbanes
Senator Heflin
Peter Simons
William V. Cowan
Thomas C. Polgar
Richard H.
Arenberg
Eleanore Hill
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Senator Boren
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Senator Cohen
Senator Trible
Sven Holmes
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Dee V. Benson
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Richard CuUen
Part Time*
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Staff Assistants
Interns
Peter V. Letsou
Joan M. Ansheles
Edward P.
Flaherty, Jr.
Barbara H. Hummel!
David G. Wiencek
Nona Balaban
Edward E.
Eldridge, III
Elizabeth J. Glennie
Stephen A. Higginson
Laura T. Kunian
Julia F. Kogan
Catherine L. Udell
Document Analyst
Historian
Volunteers
Lyndal L. Shaneyfelt
Edward L. Keenan
Lewis Liman
Catherine Roe
Susan Walsh
*The staff member was not with the Select Committee
the life of the Committee, provided services.
/hen the Report was filed but had, during
IX
United States House of Representatives
Select Committee to Investigate
Covert Arms Transactions with Iran
Majority Staff
John W. Nields. Jr.
Chief Counsel
W. Neil Eggleston
Deputy Chief Counsel
Kevin C. Miller
Staff Director
Special Deputy-
Chief Counsel
Staff Counsels
Press Liaison
Chief Clerk
Assistant Clerk
Research Director
Research Assistants
Charles Tiefer
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V. Thomas
Fryman, Jr.
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Naughton
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Birmann
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Genachowski
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Systems
Systems
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Analysts
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Zimmer
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Rosenthal
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Kristine Willie
Mary K. Yount
Minority Staff
Associate Minority
Counsel
Assistant Minority
Counsel
Minority' Research
Director
Thomas R. Smeeton
Minority Staff Director
George W. Van Cleve
Chief Minority Counsel
Richard J. Leon
Deputy Chief Minority Counsel
Robert W.
Genzman
Kenneth R. Buck
Bruce E. Fein
Minority Staff
Editor/Writer
Minority Executive
Assistant
Minority Staff
Assistant
Michael J. Malbin
Molly W. Tully
Margaret A.
Dillenburg
Committee Staff
Investigators
Director of Security
Robert A.
Bermingham
James J. Black
Thomas N.
Ciehanski
William A. Davis,
III
Clark B. Hall
Allan E. Hobron
Roger L. Kreuzer
Donald Remstein
Jack W. Taylor
Timothy E. Traylor
Bobby E. Pope
Security Officers
Editor
Deputy Editor
Associate Editor
Production Editor
Hearing Editors
Printing Clerk
Rafael Luna, Jr.
Theresa M. Martin
Milagros Martinez
Clayton C. Miller
Angel R. Torres
Joseph Foote
Lisa L. Berger
Nina Graybill
Mary J. Scroggins
David L. White
Stephen G. Regan
G. R. Beckett
Associate Staff
Representative
Hamilton
Representative
Fascell
Representative
Foley
Representative
Rodino
Representative
Brooks
Representative
Stokes
Representative
Aspin
Michael H.
Van Dusen
Christopher Kojm
R. Spencer Oliver
Bert D. Hammond
Victor Zangla
Heather S. Foley
Werner W. Brandt
M. Elaine Mielke
James J.
Schweitzer
William M. Jones
Michael J. O'Neil
Richard M. Giza
Richard E. Clark
Warren L. Nelson
Representative
Boland
Representative
Jenkins
Representative
Broomfield
Representative
Hyde
Representative
Courter
Representative
McCollum
Representative
DeWine
General Counsel to
the Clerk
Michael W. Sheehy
Robert H. Brink
Steven K. Berry
Diane S. Doman
Dennis E. Teti
Tina L. Westby
Nicholas P. Wise
Steven R. Ross
XI
Contents
Volume 23
Preface XXI
Richard, Mark M 1
Richardson, John. Jr 211
Robelo, Alfonso 46 1
Robinette, Glenn A 564
Rodriguez, Felix I 755
Roseman, David 811
Rosenblatt, William 883
Royer, Larry 995
Rudd, Glenn A 1 183
Rudd, Glenn A. (See Henry Gaffney)
Depositions
Volume 1
Airline Proprietary Project Officer.
Alvarez, Francisco J.
Allen, Charles.
Arcos, Cresencio.
Volume 2
Volume 3
Armitage, Richard.
Artiano, Martin L.
Associate DDO (CIA).
Baker, James A., III.
Barbules, Lt. Gen. Peter.
Bamett, Ana.
Bartlett, Linda June.
Bastian, James H.
Brown, Arthur E., Jr.
Byrne, Phyllis M.
Castillo, Tomas ("W").
Cave, George W.
C/CATF.
Volume 4
Channell, Carl R.
Chapman, John R. (With Billy Ray Reyer).
Chatham, Benjamin P.
CIA Air Branch Chief.
CIA Air Branch Deputy Chief.
CIA Air Branch Subordinate.
CIA Chief.
CIA Communicator.
CIA Identity "A".
XV
Volume 5
CIA Officer.
Clagett. C. Thomas, Jr.
Clark, Alfred (With Gregory Zink).
Clarke, George.
Clarridge, Dewey R.
Cline, Ray S.
C/NE.
Cohen, Harold G.
Volume 6
Collier, George E.
Cole, Gary.
Volume 7
Cooper, Charles J.
Coors, Joseph.
Corbin, Joan.
Corr, Edwin G.
Coward, John C.
Coy, Craig R
Crawford, Iain T.R.
Crawford, Susan.
Currier, Kevin W
DCM, Country 15.
DEA Agent 1.
DEA Agent 2.
DEA Agent 3.
deGraffenreid, Kenneth,
de la Torre, Hugo.
Deputy Chief "DC".
Duemling, Robert W
DIA Major.
Dietel, J. Edwin.
Dowling, Father Thomas.
Dutton, Robert C.
Earl, Robert.
Volume 8
Volume 9
XVI
Volume 10
Farber, Jacob.
Feldman. Jeffrey.
Fischer, David C.
Floor, Emanuel A.
Former CIA Officer.
Fraser, Donald.
Fraser, Edie.
Fuller, Craig L.
Volume 11
Furmark, Roy.
Gaffney, Henry.
Gaffney, Henry (With Glenn A. Rudd).
Galvin, Gen. John R.
Gantt, Florence.
Garwood, Ellen Clayton.
Gast, Lt. Gen. Philip C.
Gates, Robert M.
Glanz, Anne.
Volume 12
George, Clair.
Godard, Ronald D.
Godson, Roy S.
Golden, William.
Gomez, Francis D.
Gorman, Paul F.
Graham, Daniel O.
Gregg, Donald P.
Gregorie, Richard D
Hakim, Albert.
Hall, Wilma.
Hasenfus, Eugene.
Hirtle, Jonathan J.
Hooper, Bruce.
Volume 13
Volume 14
XVII
Hunt, Nelson Bunker.
IkJe, Fred C.
Jensen, D. Lowell.
Juchniewicz, Edward
Kagan, Robert W.
Keel, Alton G.
Kellner, Leon B.
Kelly, John H.
Kiszynski, George.
Koch, Noel C.
Kuykendall, Dan H.
Langton, William G.
Lawn, John C.
Leachman, Chris J., Jr.
Ledeen, Michael A.
Lei want, David O.
Lilac, Robert H.
Lincoln, Col. James B.
Littledale, Krishna S.
McDonald, John William.
McFarlane, Robert C.
McKay, Lt. Col. John C.
McLaughlin, Jane E.
McMahon, John N.
McMahon, Stephen.
McNeil, Frank.
Makowka, Bernard.
Marostica, Don.
Marsh, John.
Mason, Robert H.
Meese, Edwin IIL
Melton, Richard H.
Merchant, Brian T.
Meo, Philip H.
Miller, Arthur J.
Miller, Henry S.
Miller, Johnathan.
Volume 15
Volume 16
Volume 17
Volume 18
XVIII
Miller, Richard R.
Motley, Langhome A.
Mulligan, David R
Nagy. Alex G.
Napier, Shirley A.
Newington, Barbara.
North, Oliver L.
O'Boyle, William B.
Osborne, Duncan.
Owen, Robert W.
Pena, Richard.
Pickering, Thomas.
Poindexter, John M.
Posey, Thomas V.
Powell, Gen. Colin L.
Price, Charles H., II.
Proprietary Manager.
Proprietary Pilot.
Ramsey, John W.
Ransom, David M.
Volume 19
Volume 20
Volume 21
Volume 22
Raymond, Walter, Jr.
Regan, Donald T.
Reich, Otto J.
Revell, Oliver B.
Reyer, Billy Ray (See John Chapman).
Reynolds, William B.
Volume 23
Richard, Mark M.
Richardson, John, Jr.
Robelo, Alfonso.
Robinette, Glenn A.
Rodriguez, Felix I.
Roseman, David.
XIX
Rosenblatt, William.
Royer, Larry.
Rudd, Glenn A.
Rudd, Glenn A. (See Henry Gaffney).
Rugg, John J.
Russo, Vincent M.
Sanchez, Nestor.
Scharf, Lawrence.
Schweitzer, Robert L.
Sciaroni, Bretton G.
Secord, Richard V.
Shackley, Theodore G.
Sigur, Gaston J.
Simpson, Major C.
Sinclair, Thomas C.
Singlaub, John K.
Slease, Clyde H., IIL
Smith, Clifton.
Sofaer, Abraham D.
Steele, Col. James J.
Taft, William H., IV.
Tashiro, Jack T.
Teicher, Howard.
Thompson, Paul.
Tillman, Jacqueline.
Volume 24
Volume 25
Volume 26
Volume 27
Thurman, Gen. Maxwell.
Trott, Stephen S.
Tull, James L.
Vessey, John.
Walker, William G.
Watson, Samuel J., IIL
Weinberger, Caspar.
Weld, William.
Wickham, John.
Zink, Gregory (See Alfred Clark).
XX
Preface
The House Select Committee to Investigate Covert Arms Transactions with Iran
and the Senate Select Committee on Secret Military Assistance to Iran and the
Nicaraguan Opposition, under authority contained in the resolutions establishing
them (H. Res. 12 and S. Res. 23, respectively), deposed approximately 290
individuals over the course of their 10-month joint investigation.
The use of depositions enabled the Select Committees to take sworn responses
to specific interrogatories, and thereby to obtain information under oath for the
written record and develop lines of inquiry for the public hearings.
Select Committees Members and staff counsel, including House minority
counsel, determined who would be deposed, then sought subpoenas from the
Chairmen of the Select Committees, when appropriate, to compel the individuals
to appear in nonpublic sessions for questioning under oath. Many deponents
received separate subpoenas ordering them to produce certain written documents.
Members and staff traveled throughout the United States and abroad to meet
with deponents. All depositions were stenographically reported or tape-recorded
and later transcribed and duly authenticated. Deponents had the right to review
their statements after transcription and to suggest factual and technical correc-
tions to the Select Committees.
At the depositions, deponents could assert their fifth amendment privilege
to avoid self-incrimination by refusing to answer specific questions. They were
also entitled to legal representation. Most Federal Government deponents were
represented by lawyers from their agency; the majority of private individuals
retained their own counsel.
The Select Committees, after obtaining the requisite court orders, granted
limited or "use" immunity to about 20 deponents. Such immunity means that,
while a deposed individual could no longer invoke the fifth amendment to avoid
answering a question, his or her compelled responses -or leads or collateral
evidence based on those responses -could not be used in any subsequent criminal
prosecution of that individual, except a prosecution for perjury, giving a false
statement, or otherwise failing to comply with the court order.
An executive branch Declassification Committee, located in the White House,
assisted the Committee by reviewing each page of deposition transcript and some
exhibits and identifying classified matter relating to national security. Some
depositions were not reviewed or could not be declassified for security reasons.
In addition, members of the House Select Committee staff corrected obvious
typographical errors by hand and deleted personal and proprietary information
not considered germane to the investigation.
In these Depositions volumes, some of the deposition transcripts are follow-
ed by exhibits. The exhibits -documentary evidence- were developed by Select
Committees' staff in the course of the Select Committees' investigation or were
provided by the deponent in response to a subpoena. In some cases, where the
number of exhibits was very large, the House Select Committee staff chose for
inclusion in the Depositions volumes selected documents. All of the original
XXI
exhibits are stored with the rest of the Select Committees' documents with the
National Archives and Records Administration and are available for public in-
spection subject to the respective rules of the House and Senate.
The 27 volumes of the Depositions appendix, totalling more than 30,000 pages,
consist of photocopies of declassified, hand-corrected typewritten transcripts
and declassified exhibits. Deponents appear in alphabetical order.
XXII
Publications of the Senate and House
Select Committees
Report of the Congressional Committees Investigating the Iran-Contra Affair,
I volume, 1987.
Appendix A: Source Documents, 2 volumes, 1988.
Appendix B: Depositions, 27 volumes, 1988.
Appendix C: Chronology of Events, 1 volume, 1988.
Appendix D: Testimonial Chronology, 3 volumes, 1988.
All publications of the Select Committees are available from the U.S.
Government Printing Office.
XXIII
mimim
SELECT COMMITTEE TO INVESTIGATE COVERT
ARMS TRANSACTIONS WITH IRAN
U.S. HOUSE OF REPRESENTATIVES
AND
SELECT COMMITTEE ON SECRET MILITARY ASSISTANCE
TO IRAN AND THE NICARAGUAN OPPOSITION
UNITED STATES SENATE
Wednesday, August 19, 1987,
Washington, D.C.
Deposition of MARJ^ M. RICHARD, taken on behalf of the
Select Committees above cited, pursuant to notice, commencing
at 10:15 a.m. in Room 901 of the Hart Senate Office Building,
before William D. McAllister, a notary public in and for the
District of Columbia, when were present:
For the Senate Select Committee:
W. THOMAS McGOUGH, JR.
Associate Counsel
DAVE FAULKNER
For the House Select Committee:
PAMELA NAUGHTON
Assistant Counsel
Partially Declassified/Released on /'^^'^IC
ROBERT W. GENZMAN , under provisions of E.O. 12356
by N. Menan, National Security Council
82-732 0-88-2
UNCLASSIFIED
CONTENTS
Examination by counsel for
Page
House Select Conunittee (Ms. Naughton) 12, 21, 61, 74, 85,
89, 94, 113, 117, 119, 122, 144, 153, 156, 162, 170, 179, 191
Senate Select Conunittee (Mr. McGough) 3, 15, 23, 62, 75,
86, 90, 102, 115, 118, 120, 133, 147, 155, 159, 166, 173, 189
Richard Exhibits
Marked
48
53
67
81
102
104
132
140
UNCLASSIFIFO
UNCLASSIFIED
PROCEEDINGS
Whereupon,
MARK M. RICHARD was called as a witness and, after
having been first duly sworn, was examined and testified as
follows:
MR. McGOUGH: Let's go on the record. Let the
reflect that the witness has been sworn.
Mr. Richard, I'm Tom McGough from the Senate Select
Committee. Pam Naughton will be here in a moment. Dave
Faulkner is an investigator with the Senate Select Committee.
If there are any questions that I ask you that you don't
understand or would like me to clarity, please just stop me
and I'll be glad to do that.
EXAMINATION BY COUNSEL FOR THE SENATE SELECT
COMMITTEE
BY MR. McGOUGH:
Q I'd like to start, if I could, by getting a little
bit of background. But first let me ask you if you'd state
your full name and current title.
A Mark M. Richard. I am deputy assistant attorney
general in the Criminal Division, Department of Justice.
number?
A Department of Justice, 10th and Constitution 1
Avenues, N.w., wj^l^j^fjfnft flrt M^fTfVhone number, 633-2333.
imnr&wffiFfr'
SIlLASSinED
507 C Soot. N E
Vuhmroo. O C 20002
sibilities?
A I oversee three components within the Criminal
Division. Those three are the Internal Security Section, the
Office of International Affairs, and the Office of Special
Investigations, which is a component which focuses on
identifying and initiating legal action against ♦»» Nazis
living in the United States.
Q Against —
A Nazis.
Q Are you the only deputy, or are there other
deputies, Mr. Richard?
A There are a total of four deputies to the assistant
attorney general. Two of the deputies are career deputies,
and two are non-career deputies.
Q Who are the deputies at the present time?
A John C. Keeney is the senior deputy — he is a career
daputy; myself; Victoria Toensing — T-0-E-N-S-I-N-G; and Joe
Whitley. The latter tvro are non-career deputies.
when did you graduate from law school?
In 1967.
And from what law school?
Brooklyn Law School in Brooklyn, New York.
I understaf(|Kptl|ywf'0'iD(fv^^) ^^® Department of
Justice in 1967.
"mmm
UNCLASSIFIED
A That's correct — under the honor graduate program.
I have been with the department ever since.
Q In what position did you join the department?
A As a trial attorney.
Q In the Criminal Division?
A That's correct. I was assigned to the Fraud
Section as a trial attorney and essentially remained with the
section until 1976, when I was appointed chief of the Fraud
Section. And then in 1979 I assumed my current position.
Q Could you describe generally the duties of a trial
attorney in the Criminal Fraud Division?
A Well, at the time I had specific cases assigned to
me in various locations around the country, working alone or
with assistant U.S. attorneys out of particular U.S. Attorneys
Offices to develop investigations and prosecutions of various
white collar offenses falling within the jurisdiction of the
Fraud Section and to take these cases to completion through
grand jury and trial.
Q And then you became chief of that section in 1976,
is that correct?
A That's correct. In approximately 1972, following
several details of varying duration to U.S. Attorneys Offices
in Washington and in Louisiana, I was made chief of a newly
created major violators unit within the Fraud Section which
focused on interna
"tiWrttmnirifiY^^"-
#
'tK
. O C 20002
ONCUSSIFIED
In 1975 I was detailed to the then-deputy attorney
general-^ o ffige — deputy attorney general, excuse me — Harold
m
Tyler, where I served for approximately six months as trra "^
staff d i r a gter '-feo a newly created white collar crime committee
And then in 1976 I was appointed to the position of
chief of the Fraud Section.
Q What was the next professional step?
A In 1979, the then-assistant attorney general in
charge of the Criminal Division, Phil Hyman, elevated me to
ray current position, although I did not at that time neces-
sarily have the same components under my supervision.
Q How long have your components remained as they are
now? How long have they been like that?
A Assigned to me or as —
Q No. How long have you been handling those three
components?
A I've handled our Office of Special Investigations
since its creation in 1979. With respect to the Internal
Security Section, I believe I assumed responsibility for its
oversight following the departure of Robert Keek, who I
believe^in 1980 [sicl. I have/^ovorainht responsibilities
WWtf
since that time
As for the Office of International Affairs, I think
if my memory serves me correct, in 1979 when it was created byi
UNCUSSIRED
Mr. Hyman, I assumed responsibility for its oversight and
remained responsible for their operations until, I believe,
approximately 1982 when Mr. Jensen, who was then the assistant
attorney general, assigned responsibility for that office to
then-Deputy Assistant Attorney General Roger Olsen.
At that period, I also was responsible for the
oversight of our General Litigation Section, primarily
because at that time we were functioning only, I think, with
three deputies rather than the current four. During this
our Narcotics Section, our Office of Administration, and I
Q Let's take the three over which — were just dis-
cussed — Special Investigations, Internal Security, and
International Affairs. Could you tell me what the jurisdic-
A As I said, they are responsible for identifying and
initiating legal action against former Nazis who are residing
in this country illegally.
Q Is that their only responsibility?
A Essentially, although they have from time to time
been tasked by the attorney general or the deputy attorney
general with related activities, such as focusing on the
question of U.S. government involvement in hiding Nazis after
World War II, such^^^ t^lP-Klaug Jar^ie matter, we've, also
jftfHi'^JfJtilYrirn
UNCLASSIRED
been tasked to try to locate and establish whether Joseph
Mengele is alive. And those types of assignments have come
from time to time to the OSI operation.
Q Let's turn to Internal Security. What's its area?
A Internal Security is responsible for overseeing the
administration of various internal security statutes,
including those relating to espionage, export control laws,
unauthorized disclosures of classified information, and the
operation of the Classified Information Procedures Act — the
so-called CIPA. Those are the primary responsibilities of
our Internal Security Section.
Q And in International Affairs?
A International Affairs is a support organization
that is primarily responsible for securing evidence abroad
for use by both federal and state prosecutors, arranging for
the extradition of fugitives to this country and handling the
extradition requests of treaty partners around the world,
negotiating treaties for extradition, mutual legal assistance
as well as prisoner transfers. Essentially, those are the
primary responsibilities of our Office of International
Affairs.
Q As a general matter ,|
Neutrality Act matters
A Well, specifically the Internal Security Section.
Q And how about Antidef iciency Act matters? And the
::::'tmOTEr
ONCUSSIFIED
subset of that may be Boland Amendment sorts of pronunci-
ations .
A I'm not sure those particular statutes have been
assigned, if you will. Certainly the Boland Act would not be
nominally assigned because of the lack of criminal penalties.
The Antideficiency Act, if I'm not mistaken, has some
regulatory penalties, but to my understanding its administra-
tion has largely involved, if you will, questions about its
import— largely involved only the Civil Division to deal
with. But there is a chart, if you will, of specific
assignments. I would refer you to that chart.
Q That would be the U.S. Attorneys manual?
What I'd like to do is run down some names and ask
also the scope of your contact, if any. Some of the people
you may not have any contact with. The first would be Oliver
contact, did you have with him?
A I recall two occasions where I've had contact with
him directly. One related to an effort to clear some
proposed anti-terrorist legislation that we at the department
had been very interested in. And a lot of this was post-Ed
Wilson inquiry. We had, as a result of our experiences in
the Wilson matter, come up with a variety of legislative
proposals which we were
rr^Tmi*(«ffl^H
dopted by the
10
UNCUSSIFIED
administration and submitted to Congress for action.
I would place that contact in early '84, and it
involved an attempt to resolve a dispute which had emerged
between us and the CIA with respect to one particular
proposal. I think it was four or five specific legislative
proposals that we had prepared, and one of them was causing
particular concern to the CIA.
MS. NAUGHTON! Can we get more specific on that?
Was that the provision to make it a crime to plot to kill
someone outside the United States?
MR. RICHARD: That's correct. This arose from our
experience, like I said, in the Wilson case, we had a series
of individuals in the United States who were planning to
assassinate — in that case I think it was Libyan dissidents
who were located in Europe or other places outside the United
States.
And we had particular difficulty asserting jurisdic-
tion under existing statutes for such activities. In that
piirticular case, we arguably had some jurisdiction only
because gratuitously some of the overt acts took place in the
District of Columbia, and we were able to use D.C. provisions
for dealing with solicitation? But I assume we regarded that
as merely gratuitous that it occurred there, and but for that
fact we would not have had federal jurisdiction over the
transaction
m^ hmm
11
UNCLASSIHED
BY MR. McGOUGH:
Q What was Colonel North's role in the process?
A Well, as I recall, a meeting was called. Stanley
Sporkin was there and others, but I cannot identify them.
It's hazy. We were at the Old Executive Office Building. I
was seated in a fairly small office, and all I recall of this
was that there was something else going on because people
were constantly running in and out of the room. And there
was very little substantive resolution. After about a half
hour, the meeting seemed to terminate with, "Well, can't you
try to work it out with the CIA?"
There was major pressure, if you will, to have some
resolution because it appearec that there was--I don't know
whether it was a leak or an authorized statement that came
out of, I think, the White House announcing the fact that
anti-terrorism bill that was about to go up to the Hill.
Maybe I'm speculating somewhat. Maybe it was in
connection withT^tate of the union addressee. I don't
recall. But it was in the January context.
Q Do you recall any specific input that Colonel might
A No, other than "Can't you work it out?" He really
to be involved in something else at the moment.
I cannot, in terms of timing, tell you whether the
12
UNCUSSIFIED
1 proposed resolution that we had agreed on was accomplished
2 before the meeting or after the meeting. But we had — I
3 thought — worked out an arrangement whereby we provided the
4 CIA with a letter regarding the scope and applicability of
5 this proposed statute. And the thrust of our letter was that
/K6 we had envisioned that this particular proposal 44»*t would be
Ijf' 1 placed in Title XVIII in that portion.. >
8 MR. McGOUGH: Let the record reflect that Robert
9 Genzman, assistant minority of the House Committee, is in the
10 room.
11 MR. RICHARD: If I may continue.
12 MR. McGOUGH: Sure.
13 MR. RICHARD: We had indicated that we intended
14 this particular portion to go in the foreign relations
15 chapter of Title XVIII, which we at Justice had interpreted
16 as not applying to authorized government conduct. The CIA
17 was concerned that, as written, the statute would arguably
18 apply to authorized CIA activities.
19 MR. McGOUGH: You said there was a second meeting
20 with—
21 MS. NAUGHTON: Can I?
22 MR. McGOUGH: Sure.
23 EXAMINATION BY COUNSEL FOR THE HOUSE SELECT
24 COMMITTEE
"Is BY MS. NAUGHTON:
UNCIASSIHED
13
uNcusno
Q You said before that Casey had insisted on some
sort of express--
A That's correct.
Q — disclaimer on this. Was Casey personally, do you
recall?
A I certainly didn't deal with him personally on
this issue. My recollection is that Casey wanted assurances
that this proposal would not reach authorized conduct of the
agency. My information would have come from Stan Sporkin.
After we had devised this letter — and I think even
sent it over Lowell Jensen's signature--and had occasion to
discuss it with Mr. Sporkin and received clear indication
from him that this was acceptable, I subsequently learned
concerns whether the letter was adequate to protect duly
authorized government conduct.
The agency had then taken the position that the
latter was not acceptable and that they would only go along
with an express provision in the statute exempting authorized
intelligence activities. The resolution, as I recall, was
that Lowell Jensen, who at this time was the associate
attorney general, felt that that was not acceptable. And
ultimately that particular provision was dropped from the
package. ■•. 2 j ^J J ., j
r provision was
mm
That's my recollection of the whole transaction.
14
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
'fie
19
20
21
22
23
24
15
UNCLASSIREO
Q You mean the whole provision which would have made
it illegal to conspire to kill someone — to conspire in the
United States to kill someone was dropped from the anti-
terrorist —
A That particular proposed legislation, yes. It was
excluded from the package transmitted to Congress. That's my
recollection.
Q when Sporkin or anyone from the CIA or DOD, for
that matter, voiced their opposition to those provisions, did
they give any specific examples?
A No. Their concern was that it wouldn't provide
sufficient assurances to protect their personnel and that
citing the letter would not provide the comprehensive
assurances that they were seeking that personnel — duly
authorized personnel — engaging in activities otherwise
covered by the statute would not fall within the statute.
The statute, as I recall, reached not only assassi-
nations and assaults and other types of physical violence
directed against individuals abroad. So it wasn't just a
question of prohibition on murder. It was a prohibition on
any assault, if I recall correctly!
Q And was the section concerned Just solely with CIA
personnel and DOD personnel or their assets as well?
A I don't recall it coming down to that kind of
specificity in the discussion. It was just more generalized-
it was a proniDition oi
UNCLASSIHED
15
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
HC.
25
UNcussm
him concerned about the personnel .
Q Did your letter, do you recall, refer just to
personnel--in other words, U.S. government employees — or did
it cover assets as well?
A I think it talked about duly authorized conduct.
I'm not sure that it focused on any particular classes of
individuals .
This letter is available — I mean, the materials are
available. I'm not sure if they were included, but if you
need it, I'd be glad to send it over to you.
MS. NAUGHTON: Okay. Thank you.
BY MR. McGOUGH:
second conversation with Colonel North.
A Yes. That's correct.
This related to what I referred to as the^^^^B
^^H matter.
Q Let's set that aside for a moment, because I'm
going to come that. He'll talk about that in a little more
North's involvement with that.
Was that a single meeting that you were in?
A That's correct.
Q
Le meeting tnat you were
UNCLASSIHED
r
Any other contact with Colonel North that you--
I d©o,i* recallTthose two contacts. I must confess-
16
nmssm
I mean, I have attended so many meetings. I don't recall him
being in any other meeting, but it is possible.
A Well, the first meeting--it 's hard to date other
than saying some time in '81.
And the context is a group that was established by
the White House to meet weekly to review outstanding informa-
— pcrte«*-i*i possible threats against the security of the
president. It started apparently in response to information
to send in hit squads to assassinate the president.
And the White House, under Ed Hickey, who was — I
understood to be some special assistant to the president,
began to chair weekly meetings attended by a variety of
addition to the FBI sending a representative that the
Department of Justice also send a representative. In that
fashion, I was tasked by — I think it was Lowell Jensen, who
was then the ass_i_stant attorneY_qene£al , to represent the
department .
At these meetings, more often than not I went with
Jeff Harris, who was then a deputy associate attorney general
17
UNCLASSIHED
reporting to the associate attorney general, Rudy Giuliani.
I apologize for being so long-winded, but it was in
the context of those meetings that I first met Admiral
Poindexter. He attended a good number of the meetings. If
not personally, a representative of the NSC was always
present at the meetings .
So I met him in that context.
Q We're going to bring up in a few minutes a little
bit about the Wilson matter and whether that was discussed in
the context of those meetings .
Outside the context of those meetings did you have
A I had, I recall, one meeting with him relating to
one aspect of the Wilson matter.
Q This was a one-on-one meeting?
A No, the senior assistant U.S. attorney responsible
for this particular aspect, Larry Barcella, was with me.
Q Can you put any kind of time frame on that?
^_ A ■?«*. Could we stop the record and discuss?
UNCIASSIRED
MR. McGOUGH; Sure.
[Recess
MR'. McGOUGH: While we were off the record we were
discussing the contours of the questions and answers that are
going to follow in order to avoid any disclosure of classified
information, and with the witness' permission I will try just
18
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to lead hiro through a short number of questions.
BY MR- McGOUGH:
Q We were referring, when we broke, to a meeting with
Admiral Poindexter at which Mr. Barcella also attended.
Would it be fair to say that you were at that meeting to
request Admiral Poindexter 's assistance in an aspect of the
Wilson investigation that involved the State Department?
A That's correct.
Q I think at that point that's all we really needed
for the record at this point.
All right, then. Outside the Hie key subgroup and
the meeting with Admiral Poindexter that we just discussed,
did you have any other contact with Admiral Poindexter?
A I don't recall any other meetings with him.
Q Any phone calls or correspondence with him?
A I don't recall, except that — I don't recall any,
except that after Wilson was apprehended there was concern
on his ownTWithout authorization from the Department of
Justice composed a letter purporting to be from the NSC to
Wilson. And I had been contact, by a representative of the
NSC making inquiry with respect to this alleged letter. I
don't recall who initially attempted to reach me, but I think
I ultimately discussed the issue with an individual by the
name of Tanter — Ray Tanter.
iiMniA<;RiFiFn
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ONCLASSIHED
Q Phonetic— T-A-N-T-E-R7
A Yes. Something like that. But conceivably--and
for that matter, either Colonel North or Admiral Poindexter
may have been trying to initially reach me.
Q Did you ever discuss — to your recollection — or
communicate with Admiral Poindexter on any Justice Department
investigation other than the Wilson matter?
A No, not that I recall.
Q Now, I'm going to also go down a number of names
which will be familiar to you, I'm sure. But my question is
whether it be meetings, telephone calls, correspondence of
any kind, or anyone who represented — strike that — I was going
to say anyone who represented they spoke on their behalf — some
of these people who were represented by attorneys — someone
other than an attorney who was appearing who came to you on
their behalf or as an agent for them.
Richard Secord — have you ever had any personal
contact with him?
A I have never personally met the man. He obviously
was a target of what I call the Wilson investigation.
Q But you never had any personal contact with him?
Albert Hakim.
A The same category as General Secord
Thomas l^lines.
as General Secord.
IINClASSinFD
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UNCLASSIFIED
A Same.
Q Rafael Quintero.
A I've never met the man. He of course figured in
the Wilson inquiry.
A He was a target of the Wilson inquiry.
Q Again, have you ever met him personally?
A No. No, I haven't met him.
Q Michael Ledeen.
A I have never met Michael Ledeen.
Q Have you ever communicated with him or exchanged
correspondence with him, spoken to him on the phone--to the
respect to his attorney.
Q Well, maybe — what I wanted to do was — I know you've
met — you've spoken probably to attorneys who represented some
of these people.
A Yes.
Q Have you spoken to an attorney who represented Mr.
Ledeen?
A I don't recall. Let me, if I may, just explain why
I'm hesitant
a congressional inquiry regarding Mr. Ledeen which, if I
21
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4
recall correctly, was prompted by articles which appeared in
Italian newspapers concerning his involvement with some--what
was then viewed as scandals in Italy.
And some questions were raised in the article
regarding Mr. Ledeen which prompted *he congressional
inquiries of the department concerning his security clearance.
It was something along those lines. I don't recall with great
precision, but I think I had occasion to prepare a proposed
response to that congressional inquiry based on some FBI
reports that were made available to me.
During the course of that, I have no recollection
of talking to an attorney, but on the other hand, if you tell
me who the attorney is that represented Mr. Ledeen, that may
Q I don't know the answer.
A That's okay. I have no specific recollection of
talking to the attorney, but I did handle an aspect of the
congressional inquiry at that time.
MS. NAUGHTON: Excuse me. Could I ask a question?
MR. McGOUGH: Of course
BY MS. NAUGHTON:
Q I've seen that correspondence, and what I wanted to
know was did the attorney general actually participate in any
of that? Did you discuss this issue with him?
course.
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A I don't recall discussing it directly with the
attorney general. I recall the matter being at Ken Cribbs '
level. He was then, I think, counsel to the attorney
general.
And it was — I was asked to attend a meeting in his
office, and I believe present in addition to myself w»s Ken
Cribbs and Judy Hanunerschmidt , who was part of the attorney
general's staff. I just don't recall her specific title.
They had apparently — this congressional inquiry —
and didn't know how to respond to it. And they showed it to
me, and I -h^ suggested that it be sent to the Criminal
Division for normal processing, which is what I think
ultimately happened.
But I don't recall ever having occasion to discuss
it directly with the attorney general or anyone else, for
that matter.
Q Was Ellen Gersen present for that meeting?
A It's possible.
Q Did anyone at that meeting ever refer to any
A I don't recall. It was more of a how-do-we-handle
meeting — how do we respond to the congressional inquiry? It
was from one of the intelligence committeesj
Q What I'm curious about is in the normal course how
this is handled. The Office of Legislative Affairs would
m
23
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normally, l imagine, route that to you as a matter of course.
A That's correct.
Q How is it that it got to Cribbs ' attention?
A I have no idea.
MS. NAUGHTON: Thank you.
BY MR. McGOUGH:
every-day contact with Theodore Shakley.
A Again, the answer would be no, although he was part
of the Wilson inquiry.
Q How about the Max Gomez or Felix Rodriguez names?
The same person, two possible names.
A I've heard the name. If I'm not mistaken, I first
heard it in the context of the Wilson inquiry, but maybe I'm
wrong .
Q But you've never had any contact with him?
A No.
Q Donald Gregg — have you ever worked with Mr. Gregg
or had any contact with him?
A I have no recollection. My only hesitancy is it is
not unusual to attend meetings, especially at the State
Oepartment-fa cast of thousands, where you at times send
around a sign-in sheet. But whether he is at a meeting that
I'm at--it's conceivable!
Q Let me turn — let's turn, if we could, in a little
out wiiei.neL^ ne is ac a i
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UNCLASSIFIED
more detail to the Wilson matter. And let's start, although
I don't think we'll tarry long at it, at the beginning and
when you first became aware that the investigation--that
there was an investigation being conducted and Mr. Wilson was
involved.
A Well, I would place it probably in '81, when the
papers were carrying daily revelations of massive CIA-related
illegalities, all revolving around Wilson and his associates.
And it was a tremendous media blitz on the Wilson-^illegal
activities thay were engaged in by the intelligence community.
At that time, as I recall, different aspects
seemingly were of interest to probably six to ten different
U.S. Attorneys Offices around the country. And we were
terribly disjointed, no one knowing what was going on.
And it was apparent to me that the matter was being
poorly handled, in my judgment. I expressed that observation
to both Lowell Jensen and Rudy Giuliani, who were then the
^ssociatetf — someone's got to ride herd on this because the
ailsgations were — if they were true — obviously very serious
but also suggesting that there was tremendous overlap in
investigations, one district targeting the other one's
witnesses, and the other one targeting the other's subject.
It was something that cried out for some coordinatior. . There
whole panoply of different investigative agencies all over
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the place seemingly not coordinating.
At or about the same time, I think the FBI came to
the departments ae-'-do something to bring this matter under
control in terms of setting up a comprehensive investigative
and prosecutorial effort here. Accusations, of course, were
flying all over the place with respect to government com-
plicity, CIA cover-ups, and what have you.
Ultimately a meeting of all interested agencies and
U.S. Attorneys Offices was convened. It was held in the
auditorium of the FBI. I kid you not, just in terms of the
number of interested parties.
I mean, it was really — it was just a bizarre
phenomenon. Because everything that was ever wrong with this
country was being attributed to Wilson. And everything wws a<
Wilson connection. And we just didn't know if there was any
substance or not to it. Obviously, I'm being facetious.
So there was a need to try to bring it all together
and coordinate the inquiries.
What emerged was my assignment to be responsible
for trying to pull it together and make some sense to the
investigation and prosecution. And that's how the Wilson
task force, if you will, came to be created.
Q Did you select a district or districts that would
act as the center of gravity or the lead in the investigation?
Or how did you--how did you bring it all together, I guess is
26
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_ 1 my question.
2 A Well, at that time the focus of the allegations, as
3 you know, were in the District of Columbia. And we had Larry
5 charges against Wilson and others. There were several
6 ongoing inquiries that were based in D.C., but even those
7 inquiries--upon analysis, it was clear that the venue for the,
'^8 kinds of dofonooc that they were looking at was elsewhere.
9 So we brought in other districts as the information
10 began emerging. We brought in many districts — Houston, in
12 of this in Philadelphia where we quickly established that
13 that was not a Wilson matter, if you will. And we began
14 tapping into other resources from those U.S. Attorneys
15 Offices.
16 There came a point in time when the FBI at my request
17 had, in effect, categorized all the Wilson allegations and
18 had come up with some 50 or 60 different transactions, if you
19 will, which in my judgment had to be examined during the
20 course of this effort. And they ranged from classical
21 bribery to espionage_^_ illegal exportation of guns, explosives
22 and the like.
23 I had — I did, in fact, convene" regular meetings of
24 both the key prosecutors and the key investigative agencies
25 where we would — well, let me back up. First I assigned out
27
UNCLASSinED
primary responsibility for all of these transactions to
different offices and prosecutors, based on what appeared to
be logical venue at that time as then known.
And then we would meet regularly — this is primarily
at the investigative stage--to ensure that each agency and
each U.S. Attorneys Office involved would know what other
agencies were doing and planning to do with respect to
developing their particular r e Bp e naiblc areas.
We also tapped into some Criminal Division attorneys
that were utilized to augment the U.S. Attorney complements.
I trust that's responsive.
Q There came a time in early 1982, I believe, when the
EATSCO aspect of the investigation was assigned to the
Eastern District of Virginia, is that correct? Can you tell
me what went into that decision and how it came about?
A Well, I think it was clear that for that particular
case, the venue was there. I mean, you had a defrauding of--
if anything — the Pentagon. And that was a logical place for
It was seemingly the kind of case that required, in
my judgment, someone with a white collar crime background.
It was more a paper case. And we were very fortunate to have,
in my judgment, someone I consider to be an extremely good,
accomplished prosecutor in the w^^t^, ficilV^iiinig_aj;£A^ Ted
Greenberg, who was in Virginia.
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And looking around for alternative venue, on
reflection, I'm not sure it had some of the--that were in
Rhode Island and elsewhere around the country. I'm not sure
that there was any other T V > ha t I would consider to b« logical
venue other than in Virginia.
Q Did Mr. Barcella in the District of Columbia
express dismay or any problem with that assignment?
A Well, Larry Barcella wanted to be the head of the
entire task force. He wanted to be responsible for all
cases. What Larry didn't appreciate was that he was not
well-liked in terms of his ability to get along with other
agencies and other prosecutors. To me, that was a--as being
able to coordinate this kind of multi-district effort.
Q Did--in particular regard to the venue on the
EATSCO investigation, did you discuss that with the people
who were then your superiors in the Department of Justice?
A I don't recall specific discussions, but I was in
close communication with the U.S. Attorneys Office in the
Diatrict of Columbia. In fact, they were very concerned and
almost insisted on being present at every meeting that Larry
had with us because they wanted to be sure that they were
apprised of what was going on.
Q This was who?
A I think at that JtJ|ne.^welJ.,^i^ was-^oe DiGenova l/
was the first assistant
'^
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Q This was the U.S. Attorneys Office in Washington?
A John Hume, I think, was head of the Criminal
Division. He was very interested in making sure that he knew
what Larry was doing.
Q And Larry was in his office.
A Larry was in his office, yes.
Q Did you ever — leading up to that decision, did you
receive any input on that — on the allocation of that case to
the Eastern District of Virginia from anyone outside the
Department of Justice? Did anyone— did you solicit anyone's
opinion or receive anyone's recommendation as to whether that
case should be assigned to someone else out of the department'
A I don't recall. Those decisions, quite candidly,
as to where to assign the cases was, as I recall, largely
made by me based on my assessment of what we had inTthe
strength of a particular office, the venue, what else was on
their plate in terms of assignments, and what have you.
Q But no one from the NSC or from the White House or
the Department of Defense or State approached you or communi-
cated with you regarding that decision.
A I'm not even sure that they were aware of it.
Q Or the CIA — I should throw in that.
A Well, I mean I'm sure they became obviously aware
of it very quickly as to how we were
mean, it was no secret what we were doing
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But let me say the--position of Larry. Larry had
tremendous knowledge, certainly at the outset of this
particular case — knowledge that was of value. He had the
historical knowledge that was important. And I tried to
integrate him to the extent I thought appropriate in other
cases, including the EATSCO case and including the case in
Houston and even in the case in New York.
So tfe-^3 not a suggestion that Larry was cut out of
the process. He was aware and had, as far as I'm concerned,
ample opportunities to have input in critical decisions--in
fact •**»«., if you look at the record, participated in many
Eastern District grand jury sessions. But in terms of a
tactical judgment where to put this case, the record is there
Q Were you aware that at or about that same time —
that is, when the decision was made that venue lay in the
Eastern District of Virginia — that Mr. Barcella had been
approached by Michael Ledeen? Had you ever heard anything in
that regard?
A When you say approached, I'm not sure what you mean
regarding the investigation.
A I don't recall that. Somebody at some point —
someone told me that Larry Barcella had purchased his house
from Ledeen, but I don't know when I heard this or from whom.
I don't recall--Michael Ledeen — I may have known that, but--
31
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It doesn't ring a belli
Let me back up to what Q i tg£nc l«d — it's important.
The original referral or contact with the individual that
subsequently assisted in inducing Wilson to leave Libya was
through the NSC Newspaperman Hersch brought this individual
to Allen, who was then the National Security advisor. And
With the representation -of this individual could somehow help
in obtaining the apprehension of Wilson, that individual was
subsequently referred over to the department.
But I don't think Ledeen was involved in that. I
just don't recall Ledeen being involved in the Wilson matter.
Q Let's return, if we could, to the Hickey subgroup
meetings, at which you said Admiral Poindexter was in
attendance — at some of them, at any rate.
A That's correct.
Q The Wilson case came up in the context of those
meetings on one or more occasions, did they not?
A That's correct. I would generally raise it only
wlMn the group was discussing events or upcoming events that
might trigger a reaction from a foreign power. And it was in
this context that I would mention a particular event which
might happen or we anticipated would happen in the near
future which, as I said, might spark a response from
foreign power
Q In the context of those briefings or in the
I said, mi
32
UNCLASSIFIED
information that you passed on to the rest of the group, did
Major General Secord's name ever arise?
A I don't recall his name coming up in the context of
those meetings. The only thing I could suggest is that there
was a secretary present in most if not all of the meetings
that took what I always assumed were minutes. I have never
seen them. And I would refer you to those minutes.
Q Whose secretary would that have been?
A I always assumed it was someone from Mr. Mickey's
staff. I don't have a name to offer.
Q Do you know if the minutes were ever transcribed?
A I don't.
Q Did you ever see any typed or written minutes of
the meetings after the meetings that occurred?
A I don't recall seeing them. It certainly was not
routine to distribute minutes or anything like that.
naae mentioned in the course of the discussion of the Wilson
case — at any point?
A I don't recall. The subject of Egypt on occasion
did come up. But I cannot recall ever specifically mentioning
General Secord, nor could I focus in on any event that was
going to occur that would have suggested a
raised it in the context of this meeting J ■' 1 ^ f J
FIED
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But let
not somathinq t>\
say, if I may, that it was at this time
investigation and the involvement of General Secord. We
had — I forget whether we instituted or recommended it — at any
rate. General Secord had been suspended as a result of this
investigation. I think there were numerous articles about
the investigation, its impact on Egypt, and what have you.
So the fact that we were investigating the general
was no secret at that time. We had briefed various congres-
sional committees about the matter. It was just something
that was Taa r e 'iy public — going on.
Q Is it fair to say that as the investigation and
particularly the capture of Mr. Wilson played out that there
developed some tension between the FBI and some of the other
agencies or entities involved in the investigation?
A Well, one of the forces at work, if you will, that
led to the creation of this effort and coordination was the
ongoing tension between investigative agencies. And there
was a certain degree of tension between the FBI and Larry
Barcella.
Q What was _the_source ^f_that tension, as best you
could understand?
A Well, here you have — depending on how you wish to
look at a given transaction--you have agencies with a variety
of overlapping jurisdictions. A given transaction could give
the source of that tensJ
UNCLASSIFIED
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rise to FBI jurisdiction as well ATF, as well as Customs, and
what have you.
And I think you did have questions about the--you
know, what one agency was doing on one aspect and the other
agency feeling they should be the lead agency and what have
you. I mean, it's classical jurisdictional squabbles.
So part of the justification, if you will, i think,
for needing this coordinated effort was to reduce, if not
eliminate, this inter- jurisdictional problem.
Q Let's take about a five-minute recess here. I want
to clear up some things and stand up. Everybody stretch
their legs.
[Recess]
MR. McGOUGH: Let's go back on the record.
BY MR. McGOUGH:
Q Speaking of the Wilson matter for a few more
minutes — in the course of the investigation, did you ever
laarn or hear about any interest in the investigation on the
A Well, he was a target of the investigation.
Q Were you aware of any attempt by Mr. Von Marbad or
anyone associated with him to i^y^ffjgf th^:^v^^JL^^on
through governmental channels?
A I don't know whether it was through Mr. Von
„- . . .-^ — u-_i. .._ T u.™ . ^»,.„no,.,.{„„ that I think
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it was his attorney attempted at the outset to bring to the
NSC's attention what the attorney characterized as the
potential dire consequences on our relations with Egypt that
would flow from this inquiry.
If I recall correctly, Bob K4iM«, who was I think
then the general counsel of the NSC, was the one who was
handling it. The State Department was going to meet or was
pushing a meeting between the NSC and I think it was counsel
for Von Marbad. I believe so. And I think, if my memory
serves me correctly, we went through the ceiling and said no
meeting — don't meet with them. And if I recall correctly, we
were successful in cutting it off.
I must admit that my memory is vague, but I would
refer you to Jeff Smith, who's on Senator Nunn's staff, who
at that time was working with us — working with me very
closely — on the EATSCO matter. He was at the legal advisor's
office of the State Department. And I think this issue--he
and I worked together to turn off this effort, if you will.
Q In the course of your contact with the Wilson
investigation, did it ever--was there ever brought to your
attention any attempt to influence the investigation that you
felt was improper, be it on behalf of Mr. Von Marbad or
anyone else?
A Quite'cand'idly, 1 Rave no recollection of anything
that I would describe as undue influence or attempted
DNCUSSIFIED
1 influence. I obviously kept my superiors apprised of
2 developments. They were interested in different aspects of
3 the case. But they never, to my recollection, suggested
4 courses of action or vetoed courses of action that we wanted
5 to take.
7 Q Let's turn, if we could, to the hostage situation
8 and various plans — possibilities for rescuing them. Then
9 again, if we get into an area that you feel is still clas-
10 sified, let me know and we'll try to finesse it as best we
11 can.
12 But prior to the — do you have a recollection that
13 you wanted to add to the record?
14 A What would — I'm hesitating — going back to your last
15 question. One aspect of the Wilson inquiry which we looked
16 into was the relationship or possible relationship of Wilson
17 and associates with a senator. And there was concern
18 expressed because — or at least conveyed to me that I had
19 opened an investigation and commenced an investigation
20 without clearing it with my superiors that involved launching
21 investigation of the senator.
22 Q Was that investigation ultimately launched?
23 A Yes.
24 Q You say concern was expn
25 expressed concern to you about
1
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A It was more of a surprise that I had done it
without apparently clearing it or advising my superiors of
that effect. I'd be speculating that it was probably Lowell
Jensen, but I don't recall. It was what I regarded as a mila
reprimand for not following procedures, at least as they
perceived them.
an input from anyone else that sparked his own approach to
you?
A There was some surprise being expressed that it was
done without knowledge of higher officials within the
department. It was a reprimand for failure to notify rather
than focusing on substance. At least, I interpreted it that
way.
Q We have to ask for the record who the senator was .
I assume — with the caveat this is a committee document which
will be classified as committee sensitive and would not be
released absent a majority vote of the committees. At least
that aspect — any aspect of it would have to —
A Well, it involved Senator Thurmond.
Q An alleged contact with Mr. Wilson.
A Not — I don't — if I recall correctly, I don't
believe directly with Kr. Wilson. It was his associate who
indirectly was trying to purportedly influence the senator ir
some fashion to accomplish some bidding on Wilson's behalf.
ONCUSSIRED
Q All right. Let's turn to hostage rescues, if we
could.
Prior to the revelations of the arms deal in
November of '86, I understand that you were involved in
several possible efforts to rescue or ransom or secure the
release of the hostages. Could you itemize the ones in which
you were involved. And we may ask you about some of the
others in a minute.
A Not in any particular order.
I But at any rate, the
Southern District was interested in acquiring some assistance
from Switzerland, and in that fashion I became involved in
working with the Southern District to accomplish their
prosecutive objectives.
So there came a point in time when Andre Serena,
who was then the assistant legal advisor at the State
Department, thought that it might be fruitful to explore the
possibility of — maybe we should go off the record.
MR. McGOUGH: For the classified stuff?
MR. RICHARD: Yes.
MR. McGOUGH: Let's go off.
[Recess ]
UNClASSinED
uNcussm
MR. McGOUGH: Going back on the record after we
context of hostage release or rescue plans.
BY MR. McGOUGH:
Q Mr. Richard, let's refer to one you raised before
we broke,
)07 C Siren N E
I correct so far?
A That's correct.
Q And while the Justice Department gave its input on
the matter, the plan itself never really materialized.
A To my knowledge, it never did.
Q Let's turn to another incident of which — which we
discussed off the record. It involved, did it not, a
fugitive who was under indictment in the United States who--
again, through an intermediary — offered to set up a meeting
with Iranian official to discuss possible release of the
hostages. Is that correct?
A That's correct.
Q And the fugitive or his intermediary offered to do
UNCLASSIFIED
40
UNCLASSIFIED
)07 C Sum. N E
1 that in exchange for some consideration on the outstanding
2 criminal charges.
3 A Some unspecified consideration — yes.
4 Q Did the conversations — or did the discussions of
5 that proposal include, to the best of your recollection, any
6 mention or reference to what the Iranian official might want
7 in exchange for assisting in the release of the hostages?
8 A No. I don't recall if there was any specifics
9 discussed, and the notion was to sit down and listen to the
10 Iranian proposal, as I recall.
11 Q And again, that never — that meeting never came to
12 fruition.
13 A To my knowledge, it never did.
14 Q Then there was an episode involving a relative of
15 the fugitive we've just been discussing, of which — a proposal
16 of which you're general aware, is that correct, but that is
17 primarily the responsibility of Vicki Toensing in the
18 dapartment.
19 A That's correct.
20 MS. NAUGHTON: Could you— did we get on the record
21 approximately when this individual was indicted?
22 MR. McGOUGH: The fugitive we were_di^cu£^s_ing?
23 MS. NAUGHTON: Yeah.
24 MR. McGOUGH: Let's put it on the record.
"25 MR. RICHARD: I believe it was late '70's.
igitive we were aiscussim
UNCLASSIFIED
41
_ 1
2
3
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umvm
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i
MS. NAUGHTON: Do you know what the charges where?
MR. RICHARD: Illegal exportation of munitions and
other military equipment and violation of, I believe, the
munition control laws.
MS. NAUGHTON: Thank you.
BY MR. McGOUGH;
Q Now, there was an episode involving a representative
of the United States Customs Service that you indicated there
connection with that?
A Yes. On one trip to London I had occasion to visit
with the Customs attache assigned to the embassy. It is n\y
practice to try to stop by when I am in a foreign capital and
visit with law enforcement people, time permitting.
On this occasion, the Customs attache brought to my
attention the fact that two sources of theirs had indicated
an ability to effectuate the release of the hostages. The
representation was that at that time, which I would place
probably in late '85 or early '86, these individuals had
information that there was, to begin with, one additional
American hostage that we were unaware of and that for
payments of certain monies that they could accomplish the
release of the hostages. The Customs Service, as represented
by the attache, was unc
information.
mf"
42
UNCUSSIRED
as I recall, with the State Department and other members of
the Department of Justice and through exploration quickly
concluded that we were in all Hrkeiy [ale] dealing with a
scam. We referred it to the FBI for consideration of
possible criminal prosecution of these individuals for
attempting to defraud the United States.
That's my recollection of that incident.
Q All right. Let's refer briefly to two other
episodes or proposals. One — let's call it the New York
proposal and the other t.he Detroit proposal.
The New York proposal is an ongoing matter. Is that
correct?
A That's correct.
Q And the Detroit proposal is a recently closed
matter. Is that correct? The agency that had been brought
in in regard to the hostages has determined not to pursue it
further. Is that fair to say?
A It is my understanding that the matter is closed as
far as that agency is concerned. That's correct.
Q All right. Now, to your knowledge, in either the
New York matter or the Detroit matter was the NSC involved in
ONCUSSIFIED
A Not to my knowledge.
Q Are you aware of any proposal for an operation
43
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' C Scum. N E
irnmim
relating to the hostages that involved agents of the Drug
Enforcement Administration in an operational role?
A I was not aware of that. My only knowledge is
limited to what I read in the public media.
Let me, if I may, just go back and possibly amplify
or clarify a response I previously made with respect to
possible involvement in the NSC and these initiatives.
We have — at least with respect to the matters we
have been discussing — worked closely with the State Department
to coordinate these efforts. While I don't recall ever — let
me go back and stop at this moment and correct an answer I
And that was with respect to these three issues
that were the subject of a memorandum that you were aware of.
There was a meeting at Ambassador Oakley's office concerning
all three of them. And if I'm not mistaken, at that meeting
there was a representative of--I have to assume--the NSC.
Q But you can't recall who that was?
A No.
Q Or what if any input that person had?
A I don't recall that individual mentioning anything.
Q Do you recall--can you put a time frame on that
approximately?
A I would certainly peg it to the date of the
memorandum, in that--give a take a week either side of the
iu recaii.--can you put a i
UNCLASSIFIED
44
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25
UNCLASSIFIED
date of the memo.
Q And that's the memorandum that discusses or s^cs
forth an update on^^^^^^^^^^|ynitiative, the fugiti,^
initiative, and the Custvms initiative. Is that correc-7
A That's correct
you interrupted yourself --the point of qualifying your 5nswer
that to your knowledge t.'.e NSC was not involved in any ,£
these.
A Yes. My answer being a negative at that poiri; y,as
really designed to be liaiited to my contacts with them But
throughout this process I always assumed, I believe, t.^^
Ambassador Oakley or others at the State Department we;^ ^n
close contact with what I understood to be a White Hout^
group that was focusing on hostage-related issues.
Q In the context of hostage-related issues, die you
ever have any contact with Oliver North?
A I don't recall such contact, but during one vf the
incidents— whether it be the hijacking of the Achille •_,uro
or the TWA hijacking — I was on duty that evening and I ^ag
with the general counsel of the CIA a good portion of v^g day
and night.
Q Do you knoy ,ii ,it woul^ be Judge Sporkin?
A Yes
.""IMlFIEl
And there were many people in and out over a the
45
y)^ C Stren. N E.
UNCLASSIFIED
CIA at the time. I don't recall Colonel North being there,
but it's quite possible.
Q Were you aware that he was--as they say over at the
NSC — responsible for the hostage account, that he was
involved in hostage issues at all?
A I think I was aware that he was working on this
account in some capacity. It was my understanding that the
FBI had some ongoing liaison with him in some intrigue —
setting. They have a lot of acronyms that I really never
fully learned.
I do recall that we in the Criminal Division were
attempting during this time to participate in that process
because we thought it was relevant to us to directly be
present at these various meetings.
Q While we're on the subject of Colonel North's
account — or accounts — when, if ever, did you become aware
that he was also responsible for the Central American issues
at the NSC?
A I couldn't pinpoint that I was ever aware that he
was responsible for any Central American account. I knew
from media reports that he was heavily involved — or pur-
portedly heavily involved — in Central American activities.
But I couldn't pinpoint_ a ny^ specific time_tJT^at I acquired
this information.
Q Let's turn, if we could, to Central American
nt any specific time that
UNCUSSIHED
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UNCLASSIHED
issues, in particular investigations of Neutrality Act
violations or gun-running or efforts — let me put it this
way--efforts to assist the democratic resistance in Nicaragua
in particular.
Did there — was there ever a time when there was an
effort made to consolidate or coordinate investigations that
related to supplying the democratic resistance in Nicaragua?
A Well, when you say to coordinate those kind of
cases — there came a point in time in late — I think it was
mid- to late- '86 when there was Increasing congressional
concerns and pressures, if you will, for information regarding
pending inquiries.
I had, for one, been urging the Criminal Division
to pull it all together, if you will, because the cases of
interest in this area and the area I would define as one
relating to Nicaragua and the activities of the contras and
the activities relating to the Sandinistas — there was a
fragmentation within the division of responsibility, if you
will, over these cases.
Q Would they have generally come under your auspices
at all?
A Well, yes and no. I mean, part of the focus of
many of the inquiries was alleged narcotics violations, for
example. And those kinds of cases — if that was the principle
thrust of the case — would not, even though a subsidiary
47
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'JNCLASSIHED
aspect might be a neutrality- type violation.
Likewise if it's a--you know--we had cases that
would seemingly span—fecom the area of arms violations
domestically, which can go to our General Lit Section. You
had assertions of fraud of some of the humanitarian programs
that would go to our Fraud Section. And if it was straight
neutrality, it would come under my bailiwick. So there was a
seeming to me, anyway, j»i fragmentation of responsibility for
an area that was of tremendous public interest.
Q But that--as far as the consolidation, that would
have been mid- to late-1986 when that began to gain momentum.
A Well, what happened — Bill Weld began calling
sessions, if you will, of interested parties, if you will,
trying to get — as I appreciated it — an overview of what was
in the hopper, if you will, regarding Central American
activities .
Q Was the Hasenfus crash the catalyst for that sort
of thing?
A No, I don't believe there was any particular case.
The catalyst — if you're looking for a catalyst, I think it
was the increasing congressional pressure for information. We
had a list of — coming from I think the Foreign Relations
Committee on the Senate side of 25, 30 individuals and
information about these individuals that the committee -rs <'t'^<7
25lraemanding to know their status. There** a lot of cross-
48
UNCLASSIHED
^,
cutting requests coming in from Congress.
And again there was the sense that — at least I had
the sense that nobody really knew what was in the works.
MR. McGOUGH: Let me show you — let's have an
exhibit market here as Richard Deposition Exhibit 1.
[The document referred to was marked for identifica-
tion as Richard Deposition Exhibit No. 1.)
BY MR. McGOUGH:
Q This is a memorandum dated April 13, 1984 from
Stephen Trott to you and Vicki Toensing with our control
number J-4782 on it. It refers to the Boland Amendment and
requests a memorandum on that amendment.
Do you recall this memorandum?
A J««h. If I recall correctly, this was triggered by
one of many congressional requests for appointment of special
prosecutors. I'm not sure what the specific triggering?©*
titmX was.
Q Could it have been the mining of the harbors in — if
you look at the third paragraph, it says, "Richard Willard
and Ralph Tarr insist that 1341 means that if zero funds
were authorized for 'mining activity' etc. ..."
A I believe you are correct.
Q There's a — the second paragraph says, "What is the
effect of its expiration_on_ our groblem7J|_ _Do^you know what
that refers to?
49
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A I can only speculate again, but I would assume--and
it's pure speculation — that it's the question of the applic-
ability of a ny o f the special prosecutiice bi44 . But I'm just
speculating.
memorandum but this time frame that surrounded the memoran-
dum — the first time that you and your group became involved
with the Boland Amendment and its applicability to efforts in
support the Nicaraguan resistance?
A When you say the frame of time, probably so. I
would venture to say that this is in the ball park of when it
became an issue.
Q Did you and your division continue to monitor the
possible criminal implications of the Boland Amendment as it
went through its various phases?
A Quite candidly, when you say did the division
monitor the Boland Amendment — no, it didn't. As far as I was
concerned, it was a regulatory provision without criminal
penalties. So when you say monitor — the compliance aspect,
if you will — compliance with the thrust of the Boland
Amendment — quite candidly would not be something that as far
as I'm concerned would fall routinely inthe^ jurisdiction of
the Criminal Division.
Q Although in r984 that theory was being advanced,
was it not, by Mr. Willard and Mr. Tarr via the Antidef ictency
d fall routinely in the j
UNCLASSIFIED
50
ONCIASSIFIED
Act?
A Oh, yes. By all means. When you have a specific
issue that arises, obviously we would take a look at it. But
what I thought you were suggesting was that we in the
Criminal Division monitor the compliance with a variety of
congressional requirements.
Q No, I wasn't referring so much to monitoring the
compliance as I was to monitoring the evolution of the Boland
Amendment in its various manifestations to determine--to do
this sort of exercise periodically. By this exercise, I mean
that referred to in Exhibit 1.
A No, that I would probably say if it would be the
responsibility of anyone, Mary Lawton's office--the Intel-
ligence Policy Office — to monitor the evolution, if you will,
of the statute and its potential import.
This, if I recall correctly, triggered the first —
or triggered an analysis of the Antidef iciency Act and
followed on the heels of a meeting which I did attend. But I
believe it occurred between various assistant AG's in the
department .
Q Was there any decision — was there a decision made
at this time or at a later time as to which of the various
departments — various sections of the Department of Justice
would have primary jurisdiQtj.QA. o^et. Qoi4Jld.AQd Antidef iciency
Act violations?
imisiflfii
51
UNCLASSIHED
1 A I don't think it was assigned in that fashion--you
2 know, responsibility. The issue kept coming up in the
3 context of the applicability or non-applicability of the
4 special prosecutor's bill or the independent counsel's bill
5 being triggered by congressional referral, citing, among
6 other things — I don't think they ever cited the Antidef iciency
7 Act — but citing from the Boland Amendment.
Q Let's go, if we could, to an investigation in the
9 Southern District of Florida that's received a lot of
10 attention. It's been called a number of things. The
11 initial — one of the initial informants or sources of inves-
12 tigation was a fellow by the name of Garcia. It's also
13 been — I think down there it's referred to as the Costa
14 matter. You're nodding your head, so I think you know which
15 investigation I'm referring to.
16 A Yes. I'm familiar with the one you're referring to.
17 Q Can you recall what your first contact was or
awareness of it was of that investigation?
19 A Well, depending on how you define investigation,
20 the investigation that focused in Miami is an outgrowth of an
21 earlier investigation or a different investigation or a
22 segment of a larger investigation — however you want to
23 characterize it — involving the^ QlA^fy^^i,y^founder- leader by
the name of Posey. t||||j|
There was a Neutrality Act violation investigation
52
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)07 C SoiT,. N E 25
Wuhiiifrao. D C 2000J
ONCUSSIREO
52
begun I think in about '84 or '85.
Q In what district, do you recall?
A I don't think--as you will find in many Neutrality
Act cases, the bureau will open an investigation and not
necessarily bring it iiranediately to the U.S. attorney's
attention. So I think the bureau had it focused in Alabama,
where Posey was headquartered. But I'm not sure that the USA
had been apprised of it. But the bureau, in Neutrality Act
violations, works closely with our Internal Security Section.
So I can't say that the USA at this point was necessarily an
integral part of the inquiry.
But in any event, that was ongoing. I think it was
triggered or it occurred about the same time a helicopter
involving Posey's operation--it was the downing of some
plane — excuse me — or craft and the killing of a couple of men
who were traced back to being members of the CMA, if I recall
correctly.
Q Here you aware of that investigation contempor-
anoous?
A Was I aware that there was such an investigation?
Yes. I was aware that it was ongoing.
Now, how does that tie into the investigation we
are here talking about — this part of it? In March of '86 I
received a memo--not a memo--what I call a buck tag.
MR. McGOUGH: What we're showing — we've got — I'm
3ucn an investigation i"
WCLASSinED
53
UNcussra
showing the unclassified version of it, which does not
include--or I'm having marked as a deposition the unclassified
version of it, which will not include the attachment to it.
It consists — the unclassified version consists of four pages
which had been used as a — were introduced as an exhibit
during Mr. Meese's testimony.
[The document referred to was marked for identifi-
cation as Richard Deposition Exhibit No. 2.]
BY MR. McGOUGH:
Q And we have available for you the classified
portion, which is essentially all of the memorandum from Mr.
Revel to the deputy attorney general, if you would care to
i
review that. But again, because of the constraints what
we'll do is mark this as a deposition exhibit and refer to it
unless you feel it's necessary — if you want to review the FBI
memorandum .
Looking at Deposition Exhibit 2, is this the —
particularly page two — is that the buck slip to which you
wece referring a moment ago?
A That's correct.
Q Can you tell me, to the best of your recollection,
when you received that buck slip? Was that the first
the U.S. Attorneys Office in Miami?
A I believe so. The first contact that I recall with
ONCIASSIFIED
54
DNCUJJIflEO
the Southern District of Florida was triggered by this,
although I cannot say categorically that the FBI had not been
in touch with them on earlier occasions with respect to the
CMA aspect.
Q The memo to you is dated March 24 and reads, I
believe, "Please get on top of this. DLJ" — which would be a
reference to Lowell Jensen — is that correct?
A That's correct.
Q --"is giving a heads up to the NSC. He would like
us to watch over it." Am I right so far?
A That's right.
Q "Call Kellner, find out what is up, and advise him
that decision should be run by you." Is that correct?
A That's correct.
Q All right. Now, let's — first of all, let me back
up a moment .
Do you recall seeing a letter from Garcia's wife,
either to the judge involved in the case or to the Department
of- Justice essentially raising allegations about the cir-
cumstances of his prosecution?
A I don't recall seeing it, but I recall hearing
about it. I hate to assume for Mr_-_ Kellner ,^bi^t_I_cgf^ay
categorically I haven't seen it.
Q Is it possible that you had a discussion of that
letter with Mr. Kellner prior to March 24 of 1986, when yoi.
55
ONCUSSIFIED
saw the buck slip?
A Is it possible? Yes, but I assume he won't recall
it.
Q Would you have initiated that conversation — for
that conversation regarding a letter?
A On what basis would I initiate it?
Q I have no--
A When you say initiated, you're assuming I had the
letter. I don't recall doing that.
Q Do you recall initiating any conversation with Mr.
Kellner prior to receiving the buck slip as part of Exhibit 2
regarding this investigation?
A My answer is no, but you have to appreciate I can
be talking to Leon Kellner with great frequency over a
variety of issues and a variety of times. So I can't
categorically respond. I have no recollection of talking to
Q It says that Mr. Jensen is giving a heads up to the
NSC' What did you understand that to mean?
A That he was alerting them — I mean, it makes sense
when you read the content of the classified attachment why
there would be, in my judgment, a need to alert the NSC. In
fact, I think a failure to alert the NSC, in my judgment,
would be foolhardy by the department , aivei^ the_ cpn^ent^ oj^
the classified document. I mean, I — I
56
UNCLASSIFIED
Q Without going into the details of the investigation
in the classified document, can you be a little more specific
merited a heads up to the NSC?
A Well, you're talking about a plot to assassinate a
facilities and other embassy quarters of friendly and
unfriendly nations. I mean, this is stuff of potential
significance to not only the security of individuals and the
United States but in terms of tremendous foreign relations
Department, INS, Secret Service, and the whole — the other
interested agencies, it's natural that somebody in this
context better tell the NSC. Because I think it is something
that is particularly appropriate for the NSC to know about,
assuming you give any credence to the allegations.
Q In cases like this with the same sorts of implica-
tions, was it — were other briefings given to the NSC? Can
you recall any other case where a briefing was given> to the
NSC?
A Two weeks ago I briefed the NSC on a case involving
an ally. We were about to take enforcement actions that would
have tremendous ramifications on our foreign affairs. And
there was a full-blown mee
do you want to go back?
:::'::r»ll;Miii
57
1 Q But I mean, there were other occasions.
2 A What you're talking about is a law enforcement —
3 it's activity which by its very nature has potential sig-
4 nificant impact on the — obvious impact — on the security of
5 this country and how our foreign relations appears. To say
6 that somebody should not alert the NSC, I think, is foolish.
7 Who should be the one alerting them — that is an
9 Q Well, that's really the next question I wanted you
10 to address, and that is why would the deputy attorney general
11 be the one who would go over to the NSC to alert them? I
12 mean, if it's a matter of just briefing them on a matter
13 that's of interest to them, would that not be normally done
14 at your level or by the FBI or someone like that?
15 A No. By my level? No. I don't routinely brief the
16 NSC. I believe that I would request — I mean, it is atypical
17 for me to be in touch with the NSC except in the most unusual
18 circumstances.
19 The FBI — I can't speak for them in terms of routine
20 briefings and relationships with the NSC. Moreover, I can't
21 address what Is routine contact between the attorney general
22 or the associate.
23 But if I may, let me just say that sitting where I
24 sit, you have to appreciate, I think, that we are moving into
25 an area of international law enforcement. Law enforcement is
TuhmcuM. C 20002
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UNCUSSIHED
1 more and more impacting — directly and indirectly--on other
2 vital interests of this country in the international arena.
3 It's a function of a variety of factors, including the fact
4 that crime has become international. Whether it's narcotics
5 activities, terrorism, export controls, we are moving into
6 the international arena.
7 Moreover, just acquiring information abroad requires
more and more contact with foreign countries and what have
9 you. And our statutes that Congress is passing ■C'iuin dealing
10 with these issues are giving us more and more extra ter-
11 ritorial jurisdiction, so that we're constantly running into
12 this issue of dealing — or impacting on foreign affairs.
13 So quite candidly, this issue of coordinating law
14 enforcement with other vital equities of the government is
15 one that we'd better start facing up to.
16 I'm sorry if it sounds like I'm pontificating, but
17 I don't know — to just set it in context, I remember going back
18 wli«n I was testifying in the Billy Carter matter and one of
19 th« senators asked me how — why I felt it was important that
20 the attorney general notify the NSC of information we had
21 learned, and I asked the senator was he suggesting at that
22 time that the Department of Justice should not advise the
23 White House that the Libyan government had designed a plot to
24 infiltrate the White House? We should not advise the White
25 House of that fact? And I said in my judgment, that's
UNCUSSIFIED
1 irresponsible.
2 And I continue to adhere to that. You must set up
3 some realistic system of making sure that there is some
4 coordination.
5 Q Well, let me--was there — did you feel it was
6 unusual for Mr. Jensen to be the one to make that contact?
7 A I don't know, when you say unusual — I have long
8 felt that it's important for the attorney general to be — play
9 a role in NSC activities. I felt it's important to have what
10 I would regard as the Justice Department oversight into that
11 process.
12 Who should accomplish that? At what level within
13 the department? I don't know. I do not advocate that it
14 come down to my level. I think at my operational level — or
15 more operational level — you should try to minimize White
16 House contacts.
17 Q Are you aware of any other instances where the
18 d^^ty attorney general briefed the NSC on a pending inves-
19 tigation? By the deputy attorney general, it doesn't
20 necessarily mean Mr. Jensen. I mean anyone serving at that
21 point as deputy attorney general.
22 A I am not aware of any, but I would have to assume
23 that the White House contacts at the NSC level on spy cases,
24 whether it be the Pollard case, the Walker case--I would have
25 to assume that there is dialogue because of the nature of the
60
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UNCLASSIFIED
Now, I can't attest to them, but I know, for
example, the NSC will be tasking intelligence agencies to
find out what is the damage being accomplished by certain
espionage cases that we are working. And in that regard,
there is a flow of information, if you will, for what I
regard as well-founded, legitimate purposes.
Who's accomplishing it? 1 can't say.
Q The buck slip refers to — the second sentence says,
"He would like you to watch over it." What did you understand!
your assignment was at that point?
A Again, in reference to the nature of the allega-
tions, to stay on top of it, to be familiar with the ongoing
issues as they emerged, and to ensure that the case doesn't
languish, that there is —
Q Does not languish.
A That it doesn't languish. That it moves ahead to
r«solution.
Now, I've regarded this, based upon the context,
notwithstanding the way the bureau may have c a ptur ed it, that
the first of the threats, if you will, stemmed from the
^^^^^^^^^^^^^^^^Hrelationship where we
information that that was a possibility^ coupled with the
targets identified. To me, th
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Q Interest by?
A I assumed upstairs. You know, the gravamen of the
NSC interest, the gravamen of the deputy's interest, the
gravamen of the FBI interest. This is an ongoing case, and
all of a sudden the FBI is coming to the deputy. Hey look.
Look what's going on. And you read the memo. Why is the FBI
coming there but for these points?
EXAMINATION BY COUNSEL FOR THE HOUSE SELECT
COMMITTEE
BY MS- NAUGHTON:
Q Was it your understanding that this case came to
the attention of Mr. Jensen through the FBI or through the
NSC?
A No, no. I assumed it was the FBI to Jensen.
Q Do you have any basis for that assumption?
A I'm assuming that this was all being triggered by
the FBI to Jensen, by this memo that is attached. It's an
assumption based on the flow of paper, but maybe there's
another way.
Q You first received the memo as an attachment to the
buck slips, correct?
A That's right.
Q So you actually received them from Mr. Trott, is
that right?
A That's right.
UNCLASSIFIED
62
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ICIASSIREO
Q So when you received it, you did not know whether
or not Mr. Jensen had even seen it.
A Oh, I assumed so because the buck tag referred to
up.
I assumed that because the FBI buck tag--the FBI
memo was addressed to Jensen, if I'm not mistaken, that this
was triggered as a result of the FBI memo to Jensen, whether
there was a meeting or whether it was Just Jensen reading
this memo and saying, "Here's what has to be done,' I can't
tell you.
Q Okay. So you don't know if it was a function of
Jensen knowing about the case and asking the FBI to do a memo
or it's a function of the FBI bringing the case to his
attention.
A I have no idea.
EXAMINATION BY COUNSEL FOR THE SENATE SELECT
COMMITTEE
BY MR. McGOUGH:
Q The last line — the last two lines essentially ask
you to advise Kellner that decisions should be run by you.
what decisions did you understand that to mean?
A Decisions to prosecute or not prosecute.
Q The ultimate decision was then to indict or not to
indict. What about interim steps? That is, whether to issue
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grand jury subpoenas, whether to call certain witnesses,
whether to interview certain people. Did you consider those
the types of decisions?
A I really didn't--it's not something that I would
normally do, nor did I do it here — for me to run the investi-
gation. That's~I interpreted as keeping apprised of what
was going on, apprised of what they were doing, the way they
were going. And beyond that--the manual requires, at least
in a neutrality area, close coordination, but that's — I'm not
sure that I would have ever thought of— if you would take
this literally — I would have to run the investigation myself.
And certainly that's not what happened. That's not what I
considered I was being asked to do.
Q Would you assume that decisions meant the decision
to indict or not to indict?
A Well, certainly that. Certainly any major--you
know, if you're going to immunize the critical subject I
would want to know about it or something like that. If
you're going to take an enormous step, I'd want to know about
it.
that kind of supervision?
A Well, again, in the context— ^'s nSffhis case-
it's the context of the information in the memo.
Q Let me back up for a minute. I understand why-
64
UNCLASSIFIED
you've indicated why you were watching over and being advised
But there's an addition later here, and that is
you're being asked now to say--to approve or disapprove
decisions made in Miami, specifically a decision whether or
important that main Justice clear the decision to indict or
not indict?
Trott. I mean, you know, what was in his mind? I mean, I
can't tell you what was in his mind. I can tell you how I
interpreted it, and it's just--I'm not sure whether it was
triggered by--I'm not sure of the timing.
And I know we had a problem with Kellner wanting to
go with an open indictment at a point in time when we didn't
want him to go. We wanted to keep a particular indictment
sealed because —
A No, but it — well, it related to our dealings with
UNCUSSIFIED
Now, whether that influenced Steve's decision--
Steve Trott's decision--! don't know. I'm not even sure
whether this is a Steve Trott decision or a Jensen decision.
But you're asking me to speculate whether I was
concerned that Kellner might go off on his own and do
Vuhuifion. C
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UNCLASSIFIED
something that would impact adversely ^^^^^^^^Hand
elsewhere--! don't know.
Q Did you consider it unusual that you were being
instructed to clear decisions like indict or not indict?
A Yeah. It was unusual. It was unusual. Again, I
just hark back to the unusual--what I regarded as the
sensitivity of--the allegations regarding threats to indi-
viduals at enemy installations.
Q Did you consider the Neutrality Act gun-running
allegations to be as sensitive as the —
A No.
Q Did you consider those to be at all sensitive?
A Not particularly.
Q If you look at the first page of the exhibit as a
buck slip--what appears to be a buck slip from you to some--
excuse me — tell me what it is. That's probably —
A It's a handwritten v a c baJL of where I am with
respect to a particular matter. It's Just my own reminder.
There are so many things that cross ray desk at any given
time. It just keeps me apprised of what I've done on a
particular matter.
Q It indicates that on March 26 you spoke to Kellner
and that the AUSA not back yet from New Orleans .
A Not back from New Orleans. Right.
Q And you understood at that point that Mr. Feldjnan
82-732 0-88-4
UNCIASSIHED
_ 1 had gone to New Orleans to do an interview. Is that correct
2 A That's correct.
4 with Mr. Kellner on March 26?
5 A Well, when I finally reached him, which I guess was
6 the 26th, he gave me a whole different perspective of the
7 case — one that was different and reflected in the FBI memo.
8 He indicated, as I recall, that the entire story was out and
9 the wire services had it, and basically what you had was
10 something being manipulated by a couple of reporters who were
11 dealing with — in this case — Garcia in an attempt to mitigate
12 an upcoming sentence that would be imposed on Garcia for his
13 involvement in some gun charges of his own.
14 He expressed skepticism and indicated that there
15 were assertions of all sorts of government misuse — well, CIA
16 involvement in this transaction, government illegalities, and
17 what have you.
18 Q Let me interrupt. Did you take any notes during
19 that conversation?
20 A I'm not sure. I have scratch notes of conversa-
21 tions. I'm not sure that they're necessarily dated with that
22 date.
?3 MR. McGOUGH: Why don't we^put those _with — your
24
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25
notes in as Exhibit 3.
Am I on the right track? Is that in fact your
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UNCUSSIFIED
handwriting? It's a good start, because the way they come
over from —
MR. RICHARD: Can I take the Fifth on that?
MR. McGOUGH: You're going to have to.
MR. RICHARD: That's my scribble.
MR. McGOUGH: Now, it's two pages. Our control
number is J-5641 and J-5642, which we'll mark collectively as
Exhibit 3.
[The document referred to was marked for identifi-
cation as Richard Deposition Exhibit No. 3.]
MR. RICHARD: This is not the earliest — there
should be an earlier page. This is--that'3 got to be the end
of one of the later conversations.
MR. McGOUGH: Can you look at the second page? I'm
not sure — I'm not positive that the two are linked in time.
MR. RICHARD: There's a third page which is —
MR. McGOUGH: So a third page is missing. All
right, let's back up for a second here.
I think we're going to be on this topic for a
little while more. This might be a good time to break for a
half an hour or so for lunch before we turn to the notes.
Because once we get into these, we're going to be at it a
while, I think. Before XLlunaiag j.rw rhi.^m^h£ be a good
I will attempt to find — I will just go to this
68
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UNCUSSIHED
1 portion of the file and attempt to find — it didn't turn up on
2 our — read off the record.
3 [Recess]
4 BY MR. McGOUGH:
5 Q Why don't we go on the record and indicate that
6 you've looked at Deposition Exhibit 3, which is two pages of
7 handwritten notes .
8 I believe you indicated that you thought there was
9 another page that's not here. I'd appreciate it if you'd
10 tell us what you believe what was on that first page and then
11 also go on to tell us what the two pages we do have are.
12 A As I recall, the first conversation I had with USA
13 Kellner, he related to me the fact that the AP had a story
14 based on Garcia 's statement largely to the effect that Garcia
15 had been set up to keep him from revealing the proposed
16 action that had been reflected in the FBI memo. And Kellner
17 described other portions of the story. He expressed skep-
18 tlcism about Garcia 's credibility and the validity of the
19 representations, if you will.
20 We proceeded to discuss what he was doing. I think
21 at that point he had the assistant travelling to New Orleans
-22 to interview Terrell. There was a conversation — I'm not sure
23 whether it was just devoted to the results of the New Orleans
24 visit or whether it was combined with the results of the
25 Costa Rican visit by the assistant and the FBI agent--but
jlb69
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: lam. N E 25
during that conversation he relayed to me the fact that
Terrell had essentially — that his information was hearsay,
that the individuals in Costa Rica were, again, walking away
from the story.
And Js- h e ar Leon's emphasis was that that was being
subject to some manipulation by Garcia to secure some lenient
treatment by the court and that it was being hyped up by a
couple of reporters who were out to make a lot of hay from
these allegations. In fact, I think he suggested that they
might — they may have even co nopir ed the allegations or put
the seeds in Garcia 's mind, if you will.
The information reflected on the material you have
essentially corresponds with'^Leon Kellner'f' relaying it to me.
Q But not in a single telephone conversation?
A No. The notes that I have consist, I believe, of
about three pages, and I am not sure — well, I am sure that
they represent at least two conversations. Whether these two
pages you have is one conversation — I suspect it is, because
the last conversation I had with him on the telephone, was his
preliminary conclusion, which was the fact that he had
thought he had at best a weak gun case.
And his — the gravamen or the thrust of the conver-
sation was his lamenting the fact that it would be a case
^.r
that he would not normally bring. And he was concerned
because he would anticipate ±t being vilified by the media
70
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£3
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1 for not bringing a case.
2 And we agreed that he would — when the investigation
3 was concluded — that he would send up a prosecutive recommen-
4 dation which we would review and either agree with or
5 disagree with but that he was very much concerned about how
6 the media would treat him if he failed to find a prosecutable
7 case.
Q Can you put a time frame on that latter conversa-
9 tion? When is it that you're having this conversation with
10 him about the prosecutable case?
11 A I can only — I really — logic would suggest that it's
12 some time between June and October.
14 received a memorandiam over Mr. Feldman's name laying out the
15 circumstance of the case?
16 A I can't say with any certainty. It may have been
17 prior to that, because there came a point that he had an
interim memo which he was going to send up — which he did.
19 And there was additional investigation that was required that
20 he intended to undertake.
21 And he was lamenting the fact that the case did not
look promising as a prosecutive vehicle, and the fact that he
anticipated a lot of criticism from the media — from Congress-
being directed at him for what appeared to be--what prosecu-
tive judgment he would be rendering. And he was very
71
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INCLASSIFIED
Q when, if you can recall, did you first become aware
that there were allegations being made by some of the
witnesses who had been interviewed of government involvement,
be it CIA or NSC involvement? I note on one of your notes
you have Hull CIA.
A I think this — I think he--if I'm not mistaken,
right from the start there were these allegations. I think
Kellner had indicated that this was part and parcel of what
the media was asserting.
Q When you say that this was part and parcel, does
that include the NSC-Oliver North allegations as well?
A I'm not sure whether they were specific in that
regard. There was certainly wrong-doing by government
officials. Whether it was NSC specifically — it was certainly
CIA involvement, because CIA, as I recall, right from the
start was certainly involved in this plot, if you will.
Q Do you recall any discussion or effort by main
Justice to postpone a sentencing for Mr. Garcia?
A By main Justice--
Q Let me just give you a little bit of background.
There was a pleading filed in March of 1986 by — over Mr.
Feldman's signature to seek a postponement of an impending
sentencing proceeding for Mr. Garcia. And one of the
72
UNCUSSIFIED
allegations in that is that the day before, a call had come
in from main Justice asking for a postponement to explore
further apparently the possibility that Mr. Garcia might
cooperate.
A It may very well have come from me. I don't recall
it. I do recall that the sentencing was postponed. What I
thought — I don't recall specifically asking for the postpone-
ment, but I certainly — we wanted to explore Garcia 's coopera-
tion. He was the source of this information. So--
Q Is it possible — go on, I'm sorry.
A — I mean, I don't recall specifically asking,
"Let's postpone the sentencing," but it would certainly--it
would be a tactical move that I can see myself suggesting.
Q Would you have suggested it prior to March 26th or
when you saw that buck slip?
A I would have to say no, only because I don't recall
Ksllner, so I would have to assume no.
But when was that, if I may ask? You said that
MS. NAUGHTON: Mid-March.
MR. McGOUGH: Mid-March. March 19th, March 15th--
something like that.
MR. RICHARD: I knew that there" was a postponement
of this. Then I have to assume that Kellner told me as part
n: nia-narcn. piarcn i»t
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1 of the briefing. He was briefing me. He was giving me the
2 update of what was going on. So he was bringing me into the
3 picture; I wasn't bringing him into the picture.
4 The fact that a postponement of sentencing occurred
5 so as to first explore a proffer of cooperation would be to
6 me a logical step to take. I don't--just the dates suggest
7 that I didn't do it. But it would be a logical step. If
8 someone said, "Should we?", I would say, "By all means."
9 BY MR. McGOUGH:
10 Q Was there anyone else in your section or under your
11 supervision involved in this matter?
12 A Well, the Internal Security Section was getting
13 reports all the time from the FBI and what have you. Whether
14 they were in touch directly with Kellner, I can't say. I'm
15 sure — I mean, if I recall correctly, the memo reflects
16 somewhat daily contact with the Internal Security Section by
17 the FBI on the matter. They were apprised of what was going
18 on.
19 Q Did you delegate responsibility for the case to
20 anyone in specific?
21 A When you say delegate — Internal Security was
22 responsible for following the case. It's the Neutrality Act.
23 They worked historical_lj^\^ry ^l^se^ wLth_the FBI. It's a
24 close relationship.
joTCVm.. Nt 25 Did I delegate specifically anything beyond that?
Wiriwroa. C !O0D2
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UNCLASSIHED
1 No.
2 EXAMINATION BY COUNSEL FOR THE HOUSE SELECT
3 COMMITTEE
4 BY MS. NAUGHTON:
5 Q Would it have been unusual for anyone in the
6 Internal Security Section to call the U.S. attorney as
7 opposed to calling the assistant working on the case?
8 A To call the U.S. attorney?
9 Q Yes. In other words, to call Mr. Kellner as'
10 opposed to Mr. Feldman.
11 A In answer to your question, no, I don't think it
12 would be unusual for, say, someone in the management staff to
13 call the U.S. attorney. I'm not aware that anybody did make
14 such a call. But in answer to your question, it wouldn't be
15 unusual for someone in a senior position to call directly the
16 U.S. attorney.
17 Q Well, as I recall, I think Mr. Marum — is that his
18 name?
19 A Tom Manim.
20 ' Q Tom Marum?
21 A He's the deputy.
22 Q He was sort of coordinating this.
23 A He does most of the neutralitx work at the Internal
24 Security Section
25 Q Did he tell you that he had spoken to either Leon
lost of the neutrality woi
UNCIASSIHID
75
UNCLASSIFIED
Kellner or Jeff Feldman?
A NO. I don't recall him ever mentioning any
contact.
Backing up to complete the record, there was a
meeting later in October in which Kellner was in Washington.
I-. not sure whether Marum was there, but the FBI was there,
internal Security, maybe Tom Marum was there-among other
things, to discuss the status of a case.
Again, I just don't have any recollection of this
before the buck tag date. But I-like I say, if there's a
question of a cooperating witness-should we postpone the
sentencing until we have interviewed the witness, obviously
I'd say do it.
EXAMINATION BY COUNSEL FOR THE SENATE SELECT
COMMITTEE
BY MR. MCGOUGH:
Q Let's look at the notes, if you could. I know
it'll be a bit time-consuming, but given your handwriting, it
would be helpful if you could just read the notes to us so
that we have a clean record of what they say.
You're referring to the second page, now, of the
exhibit. DO you think they're reversed in time?
A I do believe so. Well, not necessarily reversed in
■"r".;:;;.:;T.BOTE..„..
76
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page of what has been marked as Exhibit 3.
A "Court probation.
"Garcia 's wife.
"Allan Sam — lunatic — but used him to make" — well,
again, these are incomplete sentences, and I apologize for it
"12/85 — conviction on gun charge.
"public defender tells AUSA that in February '85
Miami Garcia, Carr, Thomas, Hall or Hull, Jones, Carter,
Carbo — meeting in Miami.
"Discussed blowing up three embassies, killing
Tambs, and gun-running.
Okay — "We corroborate" — I don't know — "with their
people in Miami.
"In 3/85 — Thompson, Carr — weapons to Costa Rica for
above operation. Carr and Thompson and two others arrested
in Costa Rica.
"1/7/86 — Garcia polygraphed.
"1/14 — inconclusive on assassination — deceptive on
Posay" — this again is Kellner relaying to me.
"January '86 — FBI asked that Carr and Thompson be
interviewed. Carr and Thompson deny participation. Admit,
however, guns. Heard of plot in jail.
"Garcia, Jose Cotin — 1/16/86 — FBI interviews.
Implicated in Zeal murder (provided murder weapon) . Refers
FBI to Terrell
lINnUSSIFlEO
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"FBI interviews Terrell. Terrell confirms Garcia 's
story but" — well--"Terrell says it's all hearsay. 'Heard it
around.' Terrell say story.
"Frank Castro representing Ochoa at meeting, who
says to group would pay $1 million to kill Tambs . Believes that Tarns and CIA had killed Corea. Corea killed at CIA request. "Terrell saying that CIA reps present at the meeting" — representatives of the CIA were present at the meeting. "Killing of Tambs, three embassies — U.S. /Honduras and Costa Rica and Russian embassy and Costa Rica — making it all look like Sandinistas. Castro says Ochoa doesn't care who gets credit. "Garcia — tentatively" — I assume scheduled-- "tenta- tively on Monday" — crossed off — "Tuesday. "Claiming that he be prosecuted because he wouldn't go along. Tony Avignon visits Carr and Thompson. "Worked for assistant public defender in Miami. Tony visits Carr and Thompson. Tony Avignon says he also worked for '60 Minutes'. "Public defender believes it's all a CIA plot — CBS has the story. "Co-pilot--Vasquez--3on of gun runner. ^ "Summary--has case on gun charges--possibly < CUT Neutrality X*t violation. \mm\ 78 jlb78 UNCUSSIFIED Co 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 O.. MC. 25 ••Hull— CIA." Like I said, scratch notes of my telephone conver sation. Q would this all have been one telephone conversation? A I would venture to say yes, which— although it's quite possible that it's not. And I say that because the second page, where it says, "Has case on gun charges," I specifically recall that conversation when he reached that tentative assessment. That was later on in the process. The earlier notes seem to suggest an earlier period in time. So it is possible that this top page is in time subsequent to the second page. Q There was mention of lie detector tests. Did you ever learn-or to your knowledge were the lie detector or the polygraph results ever submitted to Washington for re- interpretation or review-the Garcia polygraph material? A Re-interpretation? There was an initial report that I have seen indicating that he had passed the polygraph. That was contained in a memo that I saw from Clark, who is the head of the Criminal Investigative Division, to- MS. NAUGHTON: Excuse me— of the FBI. MR. RICHARD: -of the FBI, I'm sorry-to either Buck Revel or Judge Webster. I don't recall. There's a memo from Clark that pre-dates the memo that was attached to the memo which went to Jensen-or was 79 jlb79 UNCLASSIFIED 79 addressed to Jensen. That memo characterized the results of a polygraph different, if I recall correctly, than how it was characterized in the memo to Jensen. I believe that--that can be changed just looking at the memos. But I don't recall it being resubmitted subsequent to that point. Whether it had been done prior, I don't know. But when you say — my understanding of the process is that the field gafliiyJa p he r — the individual out in the field--makes a tentative assessment and then sends the results to Washington, where they are — I don't want to say re-interpreted, but the final interpretation is made out of Washington. That's my understanding. Now, I may be wrong. Q Do you understand--or do you have any understanding or knowledge as to how the results — the statement of the results changed between the Clark memo and the Revel memo? A No. Q Did you know whether it was a matter of Mr. Clark just having his facts wrong or someone else later looking at the results and saying, "No. He didn't pass. It's incon- clusive"? A I can't — I mean, I don't know. But I hope you appreciate — I don't credit much, in my experience, the results of polygraphs. So to me it's not a critical element whether someone says that the individual passed or didn't pass. So it wouldn't bug me whether it said he passed or he 80 «Ncussife didn't. I mean, it just wouldn't be of major consideration — the results of polygraphs. That's my own view of the results. Q Now, after your initial buck slip from Mr. Trott, did you have any further contact with Trott, Jensen, or the attorney general on this case that you can recall? A I don't recall specifically discussing it with either — I certainly didn't discuss it with the attorney general. I have no recollection of discussing it with- Jensen. I have no specific recollection of discussing it with Steve Trott, but I would have to say I had to have discussed it. I mean, just knowing my practice and what I would normally do. But I have, in answer to your question, no specific recollection of doing so. Q If you look at Exhibit 2, which is the actual buck slip — or page two of Exhibit 2, which is the buck slip — I think there's an indication on there — "See me" — circled in the transmittal slip. Does that refresh your recollection? A No, not really. I mean, I can't close my eyes and picture a discussion with Steve Trott, but I am sure that I would have. This is 3cm^|t|j^CL ^^AVBUl^ifiu^^n^ly ^^^^ kept him apprised of. UlllllLAuull I LU There are so many things that I would and still — keep an assistant attorney general aware of. I am sure I did that. 81 jlbfll vn CSowi. NE UNCLASSIFIED Q To the best of your knowledge, how many times did you discuss the case with Mr. Kellner? A Probably I believe three times on the telephone. Probably. And once in person, that one being in October when we had — he was participating in a broader session, if you will, as part of, I think, our efforts in October to try to get a better grasp of all of these cases. And after that session, which ended focusing on just one case — not this case but a different case — after that meeting broke, I think we began a discussion of the status of this case. MR. McGOUGH: Let's have this marked as Exhibit 4. This appears to be a list of individuals who attended a meeting — the type of sheet you would pass around for a sign- up. MR. RICHARD: Yes. [The document referred to was marked for identifi- cation as Richard Deposition Exhibit No. 4.) BY MR. McGOUGH: Q Scanning down the list of people there, you'll note about midway or two thirds of the way down is Leon Kellner 's name. Is this the meeting to which you were referring? A There were several meetings convened by Bill Weld — like I say--acro3s the board. This looks like a sign-in sheet for one of them. I say that because if you notice the 82 jlb82 f UNcujsife participants include our Fraud Section, our Narcotics Section. There are a variety of cases. It was after a session like this where we ended up essentially spending most of our time on the humanitarian aid case. Q When you say "we," you mean you and Mr. Kellner? A The group--the entire group. We constantly tended to get bogged down. And after that meeting broke — and it was at the end of the day — I recall grabbing the people — grabbing is the wrong term — but suggesting, "Hey, look. Let's wait a few minutes and discuss this case" — however you want to caption it--the Posey case, the Costa case. So of this group, the interested parties remained. I don't think you'll find — if my memory serves me correct-- you won't find another sheet for that because it was a tag-on to a meeting like this. Q Who were the interested parties that remained for that meeting? A Myself, Leon Kellner, people from the Internal Security Section were there. Now, if it's a tag-on to this, I have to assume Tom Marum and Joe Tafe, the FBI — and I would assume that was Gail Burton. In this case, you had — let me see--George Van Balen. Al Seddon would be the logical one, I think, at that time, because he is the principle unit chief-- jibnj M wussife or I think his title is over at the FBI on Neutrality Act issues. So I suspect this type of complement, if you will. Q You recall — I'm skipping a little in time — but do you recall receiving the memo under Mr. Feldman's name in June of 1986? A That's correct. Q And that memo at the end, I believe, concluded that it was premature to issue grand jury subpoenas. Up until that point, had you discussed with Mr. Kellner or anyone in the Southern District whether or not the matter was ready to be — that subpoenas should be issued in the case? A No. I recall no discussion. In fact, I think if you look at the attached FBI memo, I think their suggestion was that it was at that time already in the grand jury. I made the mistake of following that suggestion. Q By issuing the memo that was attached to the buck slip that came to you. A Or the earlier one — the one — I'm not sure when I got the earlier one, but it was a day or two earlier in date. It was the Clark to either Revel or Webster. There was a reference, I think, in just reviewing the material at some point, because this — I noticed that it represented that there was a grand jury either sitting or was about to sit. 84 UNCLASSIFIED Q When you got the Feldman memo, if I can call it that--the memo that came out in June--at the end it said it was premature to go to a grand jury and listed some reasons. Did you find that surprising in light of the March memo from the FBI saying that a grand jury was ready to go? A I didn't pick the connection up, and that connec- tion I only made recently, because the issue of going to the grand jury or of not going to the grand jury, as far as I was concerned, was never an issue until allegations surfaced that somehow there was an attempt either to influence timing or what have you. So it was never, to me, a critical question whether to go into a grand jury or not. It was a tactical judgment that I would routinely defer to a USA. If he wants — he thinks he needs to go into a grand jury — fine. If he thinks it's premature — fine. Q But you don't recall discussing it with him up to that point. . A He may have said — at that point, no. In October when we met he was still saying, "Hey, it's just too early." Nobody at the October meeting j«fas saying no, no, no. Get it to a grand jury Again, it was a tactical judgment. EXAMINATION BY COUNSEL FOR THE HOUSE SELECT COMMITTEE )ber meeting was saying n UNCLASSIHED 85 ^21 22 23 24 MLLin MVOKTMa CO.. HC W7 C %mn N E 25 ONWSSIflED 85 BY MS. NAUGHTON: Q Could I clarify that? In October, when he was saying it's still too early to go to grand jury — when someone says go to grand jury, they can either mean indictment or subpoenas . A No, no. He was saying— at least I interpreted it-- he was certainly not saying, "I'm going to return an indict- ment," or "It's too early to return an indictment." I didn't interpret that at all. What I interpreted it as was bringing substantive witnesses before a grand jury for an interrogation. I'm not even talking about using grand jury process. I'm talking about bringing witness — fact witnesses in for questioning. Q What about grand jury subpoenas? Would you ever discuss with Mr. Kellner the timing or wisdom of issuing subpoenas for things like bank records and so forth? A No. Again, he may have mentioned that he was going to do it this way or that way. I mean, again, if — I didn't care one way or the other whether he used subpoenas or didn't. It was not an event We moment in my thinking. If he thought it was right to use a grand jury subpoena, that's fine with me. If he thought it was preij^f^j^^QJ^ _tactically unwise, that was fine with me as well. EXAMINATION BY COUNSEL FOR THE SENATE SELECT 86 jlb86 vmmB nfK u f 1 COMMITTEE 2 BY MR. McGOUGH: 3 Q After getting the memorandum in June, do you recall 4 following up on the matter at all or having any other contact 5 with the case until the October meeting you described? 6 A Well, again, I can't put the timing. There was a 7 point in time when I spoke to Kellner, and he gave me this preliminary assessment. I can't put it before or after the 9 Feldman memo. 10 I have no specific recollection, but during this 11 period-- there are highs and lows with Mr. Kellner in my 12 dealings with him, meaning that he is very much involved in 13 narcotics enforcement in the Caribbean and South America. 14 This is a major priority for me, dealing with extradition 15 treaties, mutual legal assistance, the use of grand jury subpoenas to acquire records ot- biuaClen the — doctrine developed out of his district. Those are of critical 18 iaportance to me. 9 ^yv There was a point in time in this summer hstce where 20 I recall a trip to Colombia — or from Colombia — where he asked 21 me to stop by and talk to his staff about the situation 22 regarding Ochoa in particular. These are prosecutors who are 23 moving very aggressively against these international traf- 24 fickers at great personal risk. And they took issue with some of the approaches we were tirying to take with the Colombian 87 jlb(37 4. £? M7 C SoHi. N E UNCLASSIFIED government . Kellner asked me to meet with them and explain the rationale that we were employing and which I did en route either to Bogota or from Bogota. Could I have discussed it with him at that point? Conceivably yes. I would just stress this wasn't — at least in my mind — a big-deal case. It looked like a case where you had questionable witnesses, highly suspect motivations — something that obviously had to be investigated that was being inves- tigated. I didn't detect any unusual interest in my superiors on the case, and to me it was largely being handled in a routine, expeditious fashion. It just wasn't something that I would remember or feel that I was compelled to make detailed calendar notes. Q Did Mr. Kellner come to you or forward to you or give to you affidavits via Mr. Hull that made allegations about either Senator Kerry or members of his staff? A Yes. He called me up — I'm glad you reminded me of it. He did call me up, and he said that he just received this. Apparently this package had been sent to selected members of the Congress as well to the U.S. attorney. He said that it reflected all sorts of questionable activities by the senator — let me retract — not by the senator but by the senator's staff. And I think, if I'm not mistaken, reporters themselves — attempts to influence testimony and not ONClASSinED (t!Z 1 suborn perjury and the like. 2 I think there probably could be a package available 3 to you of what the allegations were. 4 I said, "Send it up, we'll take a look at it." He 5 did. . 6 I forwarded it to Steve Trott with a noteTto be 7 handled — I think I gave him a couple of options along with my 8 recommendation. To wit, either refer to the Public Integrity 9 Section of our division, which has responsibility for 10 questionable activities by government officials, or before 11 deciding that, go interview Hull or try to get an interview 12 with him and see whether he's going to be willing to be 13 interviewed. 14 Steve Trott, I believe, sent it to Jack Keeney for 15 Keeney 's comments, and I believe ultimately it was decided 16 let's ask the FBI to go and see whether Mr. Hull is willing 17 to submit to interview now edsout this. 18 And we sent it to the FBI, and I'm not sure whether 19 the FBI made the attempt and if so, the results of it. I've 20 never seen a report on it. 21 Q Did you ever get back to Mr. Kellner on that at all 22 A I have to assume — I don^t recall specif_icair 23 telling him what we were doing. 24 Q Do you recall whether he sent them to you or '"25 whether he delivered them in person? ONCIASSIFIEO A I think he sent them. Q Do you recall him coming to your office — or being in your office and discussing the affidavits with you? A He may have. I mean, it's not unusual for--Mr. Kellner was in Washington frequently — I mean, he's in touch with a variety of officials — to stop by and say hello, whether he did it — again, it's quite possible. EXAMINATION BY COUNSEL FOR THE HOUSE SELECT COMMITTEE BY MS. NAUGHTON: Q What was his demeanor when he was talking to you about this? In other words, was he very upset about the political ramifications or this, or was he — A The whole — Q The affidavits and the problems with Senator Kerry's staff. A Hell, he was — I would describe him as feeling that it vindicated his assessment that this was part of a situation b«ljig manipulated by political forces where everybody had their own agenda — in other words, was particulary pure from a prosecutorial point of view. Garcia had his agenda — trying to get out from under a situation, reporters trying to come up with interesting stories, and Kerry's staff attempting to discredit the actions oi-rJ-^ioji' ^ know who — the CIA, the 90 UNCLASSIFIED 1 So I think this was the further vindication of an 2 approach that Kellner was articulating beginning from day 3 one — that he had skepticism about this whole situation. 4 EXAMINATION BY COUNSEL FOR THE SENATE SELECT 5 COMMITTEE 6 BY MR. McGOUGH: 7 Q Do you recall ever having any contact with anyone 8 other than Mr. Kellner in his office about this investigation? 9 Did you ever speak to Mr. Feldman? 10 A No, I don't believe so. I can't identify to you 11 the prosecutors I met with during that trip. I don't recall 12 speaking to them about this case. But it is conceivable that 13 one of them was Mr. Feldman. I mean, there were prosecutors 14 focusing — 15 Q Well, all I'm really asking you is whether you 16 recall discussing this case with anyone in that office other 17 than Mr. Kellner, like Mr. Feldman, Mr. Scharf — do you know 18 Larry Scharf? 19 A I don't know them. I may have met him, but I — 20 Q Mr. Gregory? 21 A I know Dick Gregory, but I don't recall any 22 discussion with him. _ 23 Q Miss Barnett? 24 A I know of her. '^* ChTnlcshe used to work for the 25 Criminal Division. But I know who she is. The substance--! 91 leiASSIflEB don't think — I think she's an administrative assistant or something like that. I wouldn't discuss substance with her in any event. Q How about David Liewant, another assistant down there? A No. Q There was a point in time when, in response to press inquiries, main Justice issued a statement that there was in fact no investigation being conducted in this matter or that something — that it hadn't risen to the level of an investigation. This would have been, I believe, in about May. MS. NAUGHTON: I was thinking April. MR. McGOUGH: April or May of '86— out of the Public Information Office. Do you recall receiving any inquiries like that or — just for your point of reference — the people in the Southern District were quite upset when that statement was issued, because it seemed to fuel the specula- tion that they really weren't doing much. MR. RICHARD: No, no — in answer to your question, I have heard, as a result of your activities, this assertion. I certainly didn't pick it up at the time, and I'm not sure on what it was based. I can't answer. I must confess, though, as you've seen, this whole matter has had many names now. I don't knc just a breakdown in communication oi :":;i)mi»i 92 UNCIASSIHED BY MR- MCGOUGH: Q Are you--what, if anything, do you know about the attorney general's contact with the case? A Nothing. I have never spoken with him. I have no idea other than confused media accounts of purported conversa- tions between him and Leon Kellner. But I have no first-hand information. Q To your knowledge, did anyone in the Department of Justice, or for that matter anywhere in the federal govern- ment, indicate to Mr. Feldman — Mr. Kellner in substance that he should slow his investigation or handle it in any way other than the way in which he might normally handle an investigation of that kind? A I have never told him — I never told him to slow the investigation. When any issues like that come up in any case, that's a significant move. And it's something I think I would remember. I am sure, though, I have discussed the statutes with him — possible applicable statutes. And in that regard, I have no recollection what I said to Kellner regarding the statutes. But I know normally when I talk to a USA about the neutrality laws and their applicability, I always alert him that they are tricky statutes and statj^J:§3^ thsLt j:eauj.£e_ a_ certain amount of research into them Now, I can only speculate how I may have phrased UNCUSSIFIED it — what I may have said to Kellner. But I have no recollec- tion of even discussing it with him--neutrality laws and what have you . Q So that answer is no, you did not indicate to him that he should slow down the investigation. A Slow down the investigation? No. Q To your knowledge, did anyone else in the Department of Justice or anyone else in the federal government indicate to him that he should slow down the investigation? A Mot that I'm aware. Q Did he ever discuss any such requests with you? A Let me say — well, I was going to comment that I hadn't appreciated that there was any question about the aB onymity -jof thinking in the Southern District of Florida until this whole issue arose in late '86 — questions of Washington suggesting going slow and what have you in any regard. You know — the whole what-are-you-talking-about type of rosponse on my part . Q Did you ever discuss with Mr. Kellner the implica- tions of the case in regard to any pending votes in the United States Congress? Did you ever discuss votes about contra aid with Mr. Kellner? A There was — quite candidly, throughout this period, there was always controversy on one aspect or another of the contra matter. I you ever aiscuss votes i UNCLASSIFIED 94 UNCLASSIFIED And really, I think again, from my perspective, in dealing with something with — the administration issuing all sorts of statements saying, "Look. The CIA is not doing this. The NSC is not doing this. We were fighting by the Boland Amendment. We're doing this. We're acting in good faith in compliance with all laws." All this public dialogue going on. As far as I'm concerned, we do our investigations, we take the investigation where the facts take us, and we make the judgment, and then we take the heat when it's not a particularly popular judgment. I mean, that's the approach. MR. McGOUGH: That's going to conclude my questions on this aspect of it. Maybe Pam — I don't know if you have some follow-ups on some of the things I didn't cover. MS. NAUGHTON: Yes, I do. MR. McGOUGH: But go ahead. MS. NAUGHTON: I have a couple questions. EXAMINATION BY COUNSEL FOR THE HOUSE SELECT UNCLASSIFIED COMMITTEE BY MS. NAUGHTON: Q The memo that we've referred to as the Feldman memo that came to you in June of '86 — was that generated for you? In other words, did you request it or expect it, or did that sort of come out of the blue? 95 ONClASSinEO A No. It was in the course of a conversation that I had requested Leon to keep my apprised — Leon Kellner to keep me apprised of the status and developments. And it was during the conversation — one of those status discussions — that he said he had just received or he has a memo giving a status report, which he would show me. Which he did. ^ He also showed me a copy of a complaint filed by— a civil complaint filed by the reporters, I believe, that were central to this case. But the memo was not prepared at my request, in answer to your question. Q Were you ever apprised by the FBI or anybody else regarding any connection by Glenn Robinette or Secord in that lawsuit or in this investigation? A I don't recall having any discussions with the FBI regarding this particular case. I don't remember any connection with Secord. I raaaaber just glancing over the complaint, and I think it was kind of bizarre, but I don't recall whether there were specific allegations involvina Secord. T ^" yU L J^ fi fd^ Y lengthy, I guess you know yNl)[|\o5lr llll) Q As long we're on Secord, you described some of these meetings in an attempt to sort of gather up all the contra-related cases. On October 17, the House Judiciary 96 «ws/fe Conaittee-'-a majority of the majority members sent an inquiry for independent counsel. I realize that's not your shop, but were you aware of that request, and were you aware of any results that the Public Integrity Section came to regarding Secord's involve- ment with the contra re-supply operation? A The answer to the second part of your question was no — I couldn't tell you what they concluded. I have to assume I was aware that there was another request and therefore appointment of independent counsel. But in routine fashion, I wouldn't get involved in resolving those independent counsel issues. Q Well, I was just wondering if that was, for instance, a subject of the October meeting with Mr. Kellner. A No. In fact, I don't even think — I think there was — wait, wait, wait — one moment. I don't see anybody here even from our Public Integrity Section and certainly not Jack Kamey. And I have no recollection of any independent ctmnael issues coming up at these meetings. Q Do you — were you aware that the assistant U.S. attorney and the FBI were going to down to Costa Rica the first week in April? A knew that they were there at a particular point in time. Q Do you happen to know how many trips they took to I don't know whether I was aware in advance. I 97 lb97 IINW«0 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 nc. 25 Costa Rica? A I thought one, but they may have taken more. Q Did you ever speak to anybody at the State Depart- ment or any other agency regarding this case? A I don't recall having any conversations with any other agencies regarding this whole— I'm going through the agencies. None comes to mind. Q Were there ever any inquiries made, to your knowledge, of the CIA regarding Mr. Hull? A Inquiries by us? Or you or--I understand — No, no, no. From us to the CIA? Yeah. My understanding was that the CIA was denying any relationship. I think that was from day one, as reflected in FBI memos--that they were denying ^^^^^^^^^^^^^^ there | was no ongoing relationship. Q When you spoke to Mr. Kellner the times that you did speak to him, did he indicate to you that he was speaking to anybody else in the Department of Justice? A Kellner speaks to a lot of peoole at the department I don't mean face Q Well, I mean on this particular cas : speaks to a lot of peoole at the ■-'UNCLASSIFIED 98 IINCUSSIFIED 1 A No, he never indicated — 2 Q He never referred to conversations with Mr. Jensen 3 to you or Mr. Trott. 4 A Concerning this case, no. But Mr. Kellner--he has 5 many problems which he deals with at that level, and he is in 6 touch with the Associate's Office, the Deputy's Office fairly 7 regularly. 8 But I have no knowledge on this. 9 Q But you never heard from either Kellner or from any 10 of those other people that they had been in touch on this 11 case? 12 A NO. 13 Q Have you spoken to either the attorney general, 14 Judge Jensen, Mr. Trott, or Mr. Weld about this case — let's 15 say — since November of '867 16 A Spoken in substance? No. 17 Let me go into the particulars. Certainly not the 18 attorney general. Jensen I haven't spoken to since he left 19 the department. Trott — no. I have spoken to both Weld and 20 Trott procedurally. I urged them to send this case over to 21 the independent counsel. 22 Those kinds of discussions — nothing about issues of 23 "Did you talk to Kellner or did you say anything?" I have 24 tried to avoid discussing it "25 Now, I will add, if T may^-T'had a brief conversa- iid you say anything <" i icussm 99 _ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 m KvoffTMa CO.. mc. ;Sa«,.NE 25 iB(tMi. c looo: IINCias 99 I tion only recently with Kellner about the case only after believing that your inquiries were over, because I had — well, I had been in touch with him on other matters . I avoided raising this case. And it was really in the context of again the accusations that he has had to deal with about being influenced improperly and so forth. And he was a little miffed at all of this. But it's a long way around. I hope I have answered your question. Q Did he tell you anything new that he had not told you previously? A No. Well, he just — you know, this is crazy. He wasn't influence in any way and that he only just said, It's just crazy. " I mean, I really didn't go into details. I don't remember this conversation — well, what did you say, what did I say--it'3 not that kind of a conversation. It was just-- you know — here we are. Q It's my understanding — please correct me if I'm wrong — that Mr. Kellner did not want the case sent to the independent counsel, but as a point of fact the independent counsel reviewed it and decided not to t^ke it. Is that correct? A I have no knowledge about his position. I know we--I certainly urged it. !!Nni h^mm 100 jlblOO ^ CO CO iH^gJ^oimmc wuissro 1 Q That the independent counsel take the case? 2 A Yes. For — well — I was going to say for the same 3 reasons I urged independent counsel being appointed for the 4 whole thing. 5 I don't know Mr. Kellner's position on whether to 6 send it to the independent counsel or not. 7 Q I gather that until November 1986 you were not 8 aware of Oliver North's alleged involvement with this case or 9 Mr. Hull. 10 A when you say aware of it — I knew of allegations, i 11 mean, the allegations of North being involved were public-- 12 yes on that regard. 13 Q Do you remember North's name coming up in connection 14 with this case? 15 A Yes. It was one of those--there was a long list of 16 names that were involved, if you will. And it was attributed, 17 if I 'correctly, to newspaper reports of his involvement in 18 contra activities. 19 Q Did Kellner specifically mention North or anyone 20 else at the NSC regarding this case? 21 A I have no recollection of it, except I would refer 22 you to the notes. Because I was scribbling down names, if 23 you will. And if he did, I assume it's on that first page 24 unless it's on the exhibit that you now have. "S'S Q If you could give us then your arguments for 101 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 UNCLASSIRED wanting this case to be taken or assigned to the independent counsel in December of '86. A well, I had--by that time there were the allegations of Washington interference, abuse, improper dealings. I knew Mr. Kellner's view of the prospects of making the case, and I wasn't aware that the evidence had improved in any marked way since then. And in terms of the credibility of the department, I thought it was important, given the existence of the independent counsel, that the ultimate judgment--prosecutorial judgment — be made by a component that is above suspicion in the context of this whole matter. So anything that I perceived as being controversial and arguably falling within the independent counsel's jurisdiction, I had been urging go over there. Because--! mean, I viewed this at t a nt ion as being designed to ensure public confidence in the prosecutorial judgment being rendered on a criminal matter. And that's my analysis. Q Was my statement correct earlier that the indepen- dent counsel then refused to take the case on? A That's my_understanding^ That's correct. That's my understanding. Q Thank you. I don't have any other questions. MR. McGOUGH: Let's take a look at a couple of other exhibits and just get a fix on what they may be. The ' understanding. That's < UNCLASSIFIED 102 DNCWSSIFe first is Exhibit 5. Take a look at that, if you would, Mr. Richard. Tell me what that is. Is it your handwriting, first of all? MR. RICHARD: I'd plead guilty to that. [The document referred to was marked for identifi- cation as Richard Deposition Exhibit No. 5.] EXAMINATION BY COUNSEL FOR THE SENATE SELECT COMMITTEE BY MR. McGOUGH: Q Can you give me some indication of what it refers to? A Again, this is scratch notes prepared, I believe, following a conversation I had with the U.S. attorney in Oklahoma. Q Is that Bill Price? A Bill Price. The date of December 11 suggests that that's when I talked to him. I think he indicated that Bill Handricks of our Public Integrity Section, who was then, I believe, shepherding a lot of the Iran matters for the division, had been in touch with him previously. And this is the gist of the conversation I had with Mr. Price and his briefing of me regarding an individual who had been arrested and his possAb^^ MWoLv< CIA/contra-related activities. Q Now, about a third of the way down — the individual's m& 103 yiUSSIRED name was Weekly? Is that — am I reading that correctly? W-E-E-K-L-Y? A Yes. Q About a third of the way down it says — if I'm reading correctly — "Weekly posts on tape that he's tied into CIA and Hasenf us . Said he reports to people reporting to Buah." What does that mean? A I don't know what the post means, but apparently there was a tape recording. Let me, if I may, just take a second to read through the entire page. Q Sure . A Okay. This is a matter which had just arisen in the U.S. Attorneys Office. I was getting briefed. I think ultimately we referred it to the independent counsel, if I'm not mistaken. And I don't know what happened to it. It's an individual who has been arrested and is asserting — or there is a suggestion of a relationship to the CIA and Hasenfus and the exportation of explosives to the — countries . Q And he's alleging or indicating to someone that he's connected with the CIA and that he is reporting to people who report to Bush? A That's what he's asserting. Q What is the current status, if you know? A I cannot--as far as I recall, it was referred to UNCUSSIFIED 104 jlbl04 UNCLASSIHED the — Q Referred to the IC. A — to the IC, and I just don't know the status. MR. McGOUGH: Let's take a look at Deposition Exhibit 6. If the court reporter--are you collecting the exhibits? We'll give them all to you. [The document referred to was marked for identifi- cation as Richard Deposition Exhibit No. 6.) BY MR. McGOUGH: Q Now, I surmise that this is not your handwriting on Deposition Exhibit 6. Do you recognize whose handwriting it is? A No. Q Were you present at a briefing on or about 11/24/86 at which the Kellner situation was discussed? A Who was present? Q Were you present? This would have been Monday of the — the day before the president's press conference. A I don't recall any such meeting. Q Let me ask you what may be kind of a general conclusory question on this area, and that is to your knowledge or in your opinion, was there anything about Mr. Kellner's or Mr. Feldman's handling of the Garcia-Costa investigation that you felt or feel was inappropriate? A No. I've dealt with Leon Kellner now for five, 105 23 ^24 iMLun Nvomwo co.. mc. 107 C Smn. N E 25 Wultuunn. C 20002 UNCLASSIFIED six, seven, eight years. I have the highest regard for him, and I think he's a fine prosecutor. I have no reason at all to question his handling of this case. Q Let's turn to the Southern Air Transport matter or investigation. Shortly after the Hasenfus C-123 crash, did you learn of an investigation by the FBI into the ownership and operation of the plane that had gone down? A Do you want me to do a narrative or just — Q Yeah. I mean, is that a fair starting place, when Hasenfus — as the place for your first contact with that investigation? A Yes. Do you want me to just give you a narrative? Q Give me the narrative. A Okay. The plane goes down on approximately October 8th or so — or 7th, maybe — of '86. And then there are press reports of the department running an investigation into the natter. Bill Weld asked me--Bill Weld, the assistant attorney general — asked me what I knew about it and at that time I didn't know anything about the investigation. I called Tom Marum, who was familiar with the press reports of the investigation, but he was_ii2t familiar with it An*^^*^- And again, Tt' is' the practice that a Neutrality Act 106 UNCLASSIFIED violation is generally run by the Internal Security Section before even a preliminary is done, Just for concurrence of the Internal Security Section that it's warranted. But no such contacts had been made, according to Tom. I called Leon Kellner. I asked him what's going on. He was very — angry may be too strong, but annoyed-- because he was getting hit with all sorts of press inquiries, and he knew nothing about the pending investigation. Q Can you give me a time frame of your conversation with Mr. Kellner? A It would probably be the 8th or the 9th of October. And as I said, he didn't know who authorized it, but apparently there was FBI work at the Miami field office level . What next occurred at my request — I had to ask Tom to find out what's going on, and Tom Harum sent over to me an FBI teletype from the Miami office to headquarters — a copy of that. And attached to it, he put a buck tag, and the buck tag, if I recall correctly, indicated that Buck Revel at the FBI — I forget the phraseology — was reluctant to or had ordered that no further investigation be done because he — Revel — apparently believed that it was a CIA operation. Q Now, what — this is a buck tag from? Tom to me. Handwritten? yNWSSlREO' . O C 20002 107 jlbl07 '€ mm\m A Maybe typed. It's just a — it's a transmittal sheet, and it just — Q Reflecting a conversation with Buck Revel? A No, I don't believe it reflects the source of that information other than the bureau. Tom Marum, I doubt very much, would -b« talked with Buck Revel. So presumably it would be Al Seddon or somebody else at the FBI that Tom is getting this information from. That memo comes over. I brief Weld on this. Q Can you put a time frame on that? A Again, all this is, I think, the same day. Q October 8th or 9th? A lC»*h. Uf^ . Now, Tom had asked the bureau — the FBI — to question the CIA about — you know — is there a relationship to the operation, if you will, of the Hasenfus matter? What is the relationship, if anything? That's where the matter stood on that day, as I recall. The next day, which I guess would be the 10th, I get a call from Buck Revel asking me to come over to discuss the matter. I mentioned that to Weld, who had asked me to find out what's "j^JTyTn A^ ■J"iaiWWB«»'Britt°°'^ of what's occurring. I went over to Buck Revel. I met in his office with him. And I believe he — well, another agent — I believe wmm 108 01^3 UNCUSSIFIEO his last name is Miller — Dennis Miller or something like that, but he's, I think, assigned to their general counsel- tjtpe office. And Revel said — he explained, as I recall, that the field office had gone off without headquarters' authori- zation, which is contrary to — apparently to their procedure. And they had begun a preliminary inquiry. And that's how the matter got started. And he began asking where I thought this matter should go. I was skeptical about our jurisdiction. As I appreciated the facts and from media and the letterhead memo, we had a plane that had last been in the United States, I think, three or four weeks before. It had gone down in a foreign jurisdiction apparently loaded with arms, had an American national — an American national was on board. But that was it. And I questioned — well, what is the jurisdictional base? I maan, are we to assume that the arms that Hasenfus was throwing out of the plane necessarily came from the United States? And I saw this as a serious question, because I couldn't believe the plane would take off and then sit around for four weeks before discharging i^_^_5*£?° over wherever it was — Nicaragua So I approached the conversation of where do we go from here with a certain amount of skepticism whether we had :e aiscnarging its cargo c ONCLASSinED 109 J1M09 ^ ^ ^ 19 20 21 ^^ ^ 22 ^ 23 24 ■ujH iw<MTwa ea. MC. )07 C Sum. N E 25 «uhii>ron. D C 1000] UNCLASSIHED sufficient bases for even a preliminary inquiry. We began discussing what could be done, and he says — and the discussion led me to believe that we could resolve certain things. We could take a look at the airline, the manifest, the last time it was there, and something focusing on the airlinei. And we had ultimately — by the end of the conversa- tion, which lasted 20 or 30 minutes — we had — you know — let's do some preliminary work to see whether we have a jurisdic- tional basis for a full-blown inquiry. I vaguely recall Buck mentioning that he had been contacted by North, who was making an inquiry as to what was going on. I don't know whether it was North or the NSC, but I have in the back of my mind a comment that he had made during the course of the conversation that he was--he had received in an inquiry on that. Q This was in the Cost conversation on October 10? A That's correct. And that's where we were at that time. I came back, I briefed Bill Weld and Tom Mar\un, if I recall cor- rectly. I don't recall mentioning it to Leon Kellner, although logic would suggest that I would have also called Kellner, but I have no specific recollection of doing that. And that's where the matter stood until November. Q Let me back up for a moment here before we go to no jlbliO ^ 17 . DC :oaa3 yNWSSIFlEO November . Can you be any more specific about what Hr. Revel told you Oliver North had told him? A I'm not sure it was as specific as Oliver North or else something more general like the NSC — just that they were asking again the same type of question that Bill Weld was asking — what's going on? And that's the extent of my recollection. Q There was an inquiry from North — or the NSC, rather — the provision of information or request to do something or not to do something. A That's correct. I have this generalized recollec- tion that this was a prefatory statement that Buck Revel made Q All right. So we go to the next step. A The next — and here I may have my dates wrong. I don't have any dates to offer. But there came a point in time when I ^et a call fzQB defense counsel for Hasenfus — Spaulding firm in Atlanta. They were asking for some assistance from the Criminal Division with respect to legal research and precedent and opposition on a variety of legal issues. And I called the State Department — Mike Cosack, I think, in particular. He was with the Legal Advisor's Office. I basically said, "Are you working with them? What is our relationship to defense counsel?" Ill jlblll _ 1 2 3 4 5 6 7 8 9 10 11 13 14 15 ^ ONCIASSIFIED And he said, "Well, Hasenfus is a private citizen. He's not a government employee, and we should treat counsel as we would in any situation where an American national abroad gets into trouble and hires defense counsel to represent him in a foreign country," and basically that there is no governmental relationship to Hasenfus . And it was on that basis that we dealt with Hasenfus' attorneys. We gave them good public record information, but nothing beyond that in terms of assistance and what have you. Now, I'm having difficulty pinpointing when that defense counsel issue occurred, but the next/e^^on that I'm 3f 'Tbccurrii aware otfoccnrting on this matter is in November, when John Martin, the head of the Internal Security Section, sent a memo to Weld which, in the paper process, has to cross my desk, attaching to John's memo a copy of a note from Judge Webster to Floyd Clark, a memo reflecting a request from, I think, the attorney general, requesting a delay of the inquiry for ten days because of some pending potential impact on hostage negotiations or something like that. That was the first I was aware o^ that there was a delay or that there was any request for a delay. I was not familiar with this request. I showed it to Jack Keeney because it concerned me no end that we were in the midst of a request for a delay in a criminal investigation for reasons 112 _ 1 2 3 4 6 7 8 9 10 11 12 13 14 15 16 ^ # # ONCLSSSIFIED that were not particularly clear to me. There was just a lot of — this was a point in time where a lot of what is now the Iran matter was becoming public, and it's just very confused. And I was distressed to see this kind of memo. I brought it into Mr. Weld. He shared, I think, ^^,vt. concern and suggested I raise it with Steve Trott. John's memo — John Martin's memo — had indicated that we, because the initial request was only for a ten-day delay and that ten days had long expired, that he — John — unless he heard to the contrary would assume that it had elapsed and a request for delay was no longer operative. Q So by the time you saw it, the ten days had already expired. A Yes. I can't — let me see if I have a date. Well, yes-- Judge Webster's memo apparently was dated October 31, and this is something hitting my desk on the 12th of November. Q And up until that point you had not been aware that th«re was a request for a hold-up in the investigation? A That's correct. Coincidentally, John Martin and I were scheduled to meet with Steve Trott that same day on, 1 think, the Walker case — spy case. And Bill, aware of this, suggested that we raise it with Steve at that time — Steve Trott — at that time. Q Was Mr. Weld aware of the ten-day delay? A He did not indicate any foreknowledge of that 113 jlbil3 llUtll MrOfTTM ONCUSSIRED delay. He appeared as surprised as I was. At the meeting later that day with Steve Trott, I took the occasion to raise it. I showed him John Martin's memo and Judge Webster's memo. My recollection is he tried to reach the director to find out whether--! 'm sorry--to discuss the status and was not successful. And he said he would get back to us. Q Did Mr. Trott appear to have any prior knowledge of the ten-day delay? A Yes. EXAMINATION BY COUNSEL FOR THE HOUSE SELECT COMMITTEE BY MS. NAUGHTON: Q Did he explain to you what the purpose of the delay was? A I don't believe so. Other than that it was related to our attempts to secure the release of the hostages . Quite candidly, the memo — Webster's memo to Clark-- r«f lects hostages . But I must confess that in my own mind I had thought they were talking about a trade for Hasenfus, because at or about the sane time there were public reports of Judge Bell, who was representing Hasenfus in Nicaragua, talking about trades with the Nicaraguans. But I had this notion of this connection, if you will, to the Hasenfus case. At any rate, Steve Trott I do not recall going into 114 ■MUSI mpotrrwa co . mc. )07 C Sutn. N E 2 5 »u)un«oa D C :0002 Mmsim any of the bases for the request. Q I guess I'm not clear then, because you said earlier that you were a bit concerned because all of the public hoopla over the Iranian arms deal had of course come to light in the past week or so. Did you not then connect Webster's memo? A The whole question of — I'm not sure how I can answer. I recall in my own mind speculating that it was a Hasenfus trade. Whether the--how that came up in the context of what was going on publicly at that time, I don't recall. I remember I was speculating that it was a Hasenfus trade. I just — a request for delaying an investigation for whatever reason is a serious question. Now, it's done. There are legitimate enforcement reasons for doing it. But in this context at this time, it just looked like a bad — Q When did you first make the connection, then, between the Webster memo in reference to hostages and what was going on in Iran? A I'm not sure. I would have to say after I learned of the nature of it, I'm not sure that I connected it with the hostages in Iran. Q In other words, Trott did not tell you that. A I don't believe he did. EXAMINATION BY CflUMSeL J'OB XHfi. £E1IA1E_SELECT COMMITTEE mmm 115 1 2 3 4 5 6 7 8 9 10 H 12 13 14 15 16 17 18 19 20 21 W 22 23 24 ICO.. MC 25 WUXSIfiED ^ BY MR. McGOUGH: Q In your conversation with Mr. Trott, he indicated that he would check with Webster. A That's correct. He tried to place a call while we were there. Judge Webster was not available. Q The memo from — that Mr. Martin forwarded to you-- reflected that Attorney General Meese had initially requested the delay from Director Webster, did it not? A I don't recall — it's reflected in the memo. I'm not sure whether it reflects that Steve Trott had asked Judge Webster for the delay or the attorney general had asked for it. I just don't recall the particular — Q I guess my question is why would either Mr. — if it were Mr. Trott who requested the delay initially, why would he be checking with Judge Webster to see if it was okay to lift the delay? A No. But the delay had already been lifted. The t«n days had expired. The ten days had expired already by the time we were talking with Steve Trott, and what I assumed was that the call to Webster was designed to see how we resumed it-- -hew we resumed the inquiry. Q Was there that conversation? rney general in Oh, I believe Steve Trott had indicated that he had 116 )07 C Stren. N E Ttihinftoa. O C 2000: UNCLASSIFIED requested the delay at the behest of the attorney general. Q Was there any indication by Mr. Trott that he would check with the attorney general to see if it was all right to lift the delay? A No, that's not ray recollection. My recollection is only to check with Judge Webster to see whether the delay had been lifted. Q What happened next? A I think, by and large, everybody knows of the- events dealing with the Hasenfus matter that I'ra aware of. Q In your discussiort with Mr. Trott, did Oliver North's name come up in any way? A I don't recall that. Q How about the National Security Council as a whole? A I don't know whether it was at that meeting or in a subsequent conversation with Mr. Trott where I was led to believe that all of this came at the behest of the National Security Council. I don't believe that that was discussed on the occasion of the meeting with John Martin and Mr. Trott. Q Was there any discussion about why a delay was necessary in the first place? A No. No substantive discussion that I recall. MR. McGOUGH: That's all I have. EXAMINATION BY COUNSEL FOIL mE-UflUfiE SELECT COMMITTEE 117 jlbll? S ^ W7 C Sum. N E UNCLASSIFIED BY MS. NAUGHTON: Q Was that — was the Hasenfus case discussed at that October meeting — that big meeting that Weld called regarding the contra-- A There were two meetings that Weld had called. Both of them got bogged down, I think, on both occasions on the humanitarian case, if I'm not mistaken. Q You don't recall any substantive discussion. A No. Q Were you aware of a parallel Customs investigation of SAT? A No, I wasn't until public revelations that appar- ently there had been a parallel request made of Customs. Q So the FBI — Revel — did not indicate to you that he knew of a Customs investigation. A I don't recall. He may have indicated that Customs was doing their own investigation, or — I cannot say — he may have mentioned it. Q Did Trott mention it? A No. Q Do you know — as a matter of course, before a Customs agent in the field can initiate an investigation — my understanding is they focused on the plane as opposed to the cargo. Would they also have checked with main Justice? A They don't need our authority to investigate. The 118 1 2 3 4 5 6 7 8 9 I I 10 j 11 I 12 I i 13 i ! 14 i I 15 I -i I 17 18 19 20 21 22 23 )07 C SaT«. N E Wuhinffion. D C UNCLASSIHEO predicate, if you will, for the FBI, was a possible neutrality: violation. The predicate for a Customs investigation would be illegal exportation of equipment. i Again, it's one of those parallel overlapping 1 jurisdiction. | Q Did you during the course of this--now, this is, j let's say, from October 6 until November 20 or so — speak to j anybody at Customs, specifically Rafe Lopez or — A Did I speak to him? Q --or anybody about their investigation? A No. I did not. I know these individuals, obvi- ously. MS. NAUGHTON: That's all I have. EXAMINATION BY COUNSEL FOR THE SENATE SELECT COMMITTEE BY MR. McGOUGH: Q Let's turn to^^^^H||^^| When did you first become aware of the^^^^^^^Hprosecution? A Probably when he was in^^^B-probably went back to '85. Q You were aware — you were tracking the — you weren't tracking — but you were aware of the prosecution fron inception A No. My interest was in connection with the operation of the Office of International Affairs. I forget J — but you were aware of the prosecution fjJJ'-it^ " —"-UNCLASSIFIED 119 jlbll9 < 1 2 3 4 5 6 7 8 9 10 11 i 12! 13 14 15 16 17 UNCLASSIFIED 19 20 21 22 23 - I 24 j CO.. HC. I the sequence, but he had fled, and he was, I think, infl^l And we were making some efforts to extradite or persuade the o expel him. And it was in that connection, i believe, I first had contact with the case. Q Did there come a time when someone initiated or-- when there were discussions about giving ^^^^^^^| some consideration on his sentence? A Yes. Q Can you tell me about that? EXAMINATION BY COUNSEL FOR THE HOUSE SELECT COMMITTEE BY MS. NAUGHTON: Q First of all, can we ask what he was indicted for and convicted? A He was indicted for multiple counts of conspiring tofa« engaging efforts to assassinate flHHHHHj^^^^l So I think he was charged with murder for hire and related types of offenses. He ultimately plead to two counts of murder for hire. Q What was his maximum exposure? A To what he plead to? Yeah. Ten years . UNClASSinEO And this was prosecuted again, I gather, out of the 120 jlbl20 ^ ^ ^ ^07 C SuCTi, N E 1 2 3 4 5 6 7 8 9 10 H 12 13 14 t 15 16 17 18 19 20 21 22 23 24 MC. 25 UNCUSSIFIED A That's correct. He was charged with others who were also charged, I believe, with various narcotics offenses. I don't believe ras specifically charged with the narcotics offenses . EXAMINATION BY COUNSEL FOR THE SENATE SELECT COMMITTEE BY MR. McGOUGH: Q In response to my earlier question, you indicated that there were in fact discussions of giving! ^^^Hsome consideration. Can you tell me how those were j initiated? A Well, I can only speak for myself, and I say that because there were significant efforts made by persons with the Department of Defense as well as those assigned to the State Department who tried to secure preferential treatment | for this defendant. Those approaches were, in my understand- I ing, were made directly to the U.S. Attorneys Office way j ^ before we in Washington really became aware--at least to my ] knowledge--of what was going on. I think I first learned of this aspect of the matter when Jim Michel of the State Department, who is Elliott Abrams'--one of Elliott Abrams ' deputies, and I had a discussion. I may have my timing wrong. I may have first discussed it with Mike Cosack at the Legal Advisor's Offio 121 3 4 5 9 10 11 12 13 14 1 I 15 1 16 17 18 19 20 21 wsjife But at any rate, it was a dialogue that began between myself, Mike Cosack, and Jim Michel. And it was a very strange situation that we found ourselves in, because including individuals detailed from DOD to the State Department, were seeking to secure M-^9m:reatment for i[^^^^^^Hnot neces- sarily on behalf of their agency but as individuals. They were seeking to make known their views. In addition, we began receiving communications from the^^^^^^^^^^^^^^^^^^^^^^^^^^^^Hwas to the president. I think he wrote to the court seeking some consideration fori Mr. Michel, myself, and Mr. Cosack had sojiie discussions and along with^^^^^^^^^^B concluded that this was crazy, that there was no basis for this, and that we were going to oppose this kind of treatment for an individual that essentially we have viewed and had publicly stated we viewed as an international terrorist. So we were quite emphatic about our position and were resisting these efforts, if you will, to somehow get the gc^v^ treatment tol WtMRffi"" 22 That was our posture. We had a meeting with State by ^^^^^^^^^^^^^H which affordec^^^ 24 I opportunity to convince us that there were good and valid and 25 I legitimate reasons why we should as a government qo into 122 UNCUSSIflED court and seek some consideration for this man. Q Let me interject there. What were the reasons given for ^^^^referential treatment? A He was a friend of the U.S. He had helped the U.S. Q Were they more specific than that? A Veiry vague, very general. And we were never, to my satisfaction, able to get any specifics. EXAMINATION BY COUNSEL FOR THE HOUSE SELECT COMMITTEE BY MS. NAUGHTON: Q Did you get a sense of whether this was all retrospective or whether he was still working for us? A Oh, no. I had assumed it was just for historical relationships. Q Did anybody from the agency attend? A Again, this is where I come back to a cast of thousands. There were many people there. Q Well, at any rate, was the agency heard from in this whole — A I don't--I'm not aware that the agency waded in on this. This was purelj-^^ a^DOD j.nit^ajt_ive^ as far as I could tell. So we listened, and State was most emphatic on this one--no reason why to give into this — 123 jlbi23 ^ ^ 1 2 3 4 5 6 7 8 9 10 i 11 12 13 14 15 16 17 18 19 20 21 22 23 24 MC. 25 UNCUSSIFIED MR. McGOUGH: You say State was very emphatic? MR. RICHARD: It didn't want it to go over. MR. McGOUGH: Did not want to give preferential treatment? MR. RICHARD: Did not endorse it. The State and Justice were walking hand-in-hand on this issue. And it was a very peculiar situation, because in a way DOD was not institutionally supporting it. But these individuals were coining up and always prefacing their positions as speaking as an individual and going from there. And, in fact, the court was sympathetic and was receiving information from individuals such as-- BY MS. NAUGHTON: Q So these people^^^^^^^|were contacting the court directly. A Well, they were serving as character witnesses. When there came a point in time after the plea, they were writing in with pleas for leniency. I think I had a sense of hearing they testified in his behalf. So you have this series of pleas coming in from--l wouldn't say DOD representatives, but individuals affiliated with DOD, as well as the^^^^^^^^^^^^^^ And we were, as I said, opposed to it. And the instructions to^^^^were just proceed in a normal fashion, dispose of the case as you would 124 J1M24 .!*^ ' C Sum N E WUSJIBfD normally, evaluate it in normal terms. And ultimately a plea was entered, a sentence imposed — I think for five years concurrent, if I'm not mistaken — and the man ordered to surrender. Then there came a point in time--I would say probably around the 1st, 2nd, or 3rd of October--when I got a call from Steve Trott, I believe it was, asking me to attend a meeting with Buck Revel ^^^^^^^^^^^^Hthing over the Executive Office Building. I forget whether it was immedi- ately or first thing the next morning. But I go over with Buck Revel, and we go into-- I have to assume it was Oliver North's office. And present is Dewey Clarridge, Oliver North, Abrams --Elliott Abrams--and an individual who was introduced to me as a retired general. His name was given. I have forgotten it, but I believe j people have told me it was General Gorman. i And the purpose of the meeting, as announced by I Colonel North, was that egarding this latest plea, which seemed to be centered on the fact that^^^^^^^Hhad since surrendered to begin serving his sentence. It was unclear — I got the impression that^^^^^^ ^^^|thought he was going to go in from one entrance and out 125 UNCUSSinED the other entrance--you know, and out the rear. Q Did you get this impression from North? Did you have it before you went to the meeting? Let's put it that way. A Well, I got the impression that that was what was t r i g g e r i n g ^^^^^^U^^^^^^^^^^^^^^^^^^^H really holding him--that was the sense I had. Like any--he didn't anticipate it — like he really thought, you know-- Q What I'm asking is from whom did you get this impression? Was from reading ^^^^^^^^^^^^Hor was from North told you? A It's a valid question. Let me reflect on it. I think that was mentioned at this meeting. Like what did he expect? And maybe I said it, but it was like^H ^^^B^s I understood it from, I think, either Colonel North or from the generaJ And maybe I ventured to say, "Well, it sounds like he expected to walk right out." MR. McGOUGH: At any rate, was he sentenced and then ordered to surrender at a later date? MR. RICHARD: He had surrendered. MR. McGOUGH: Bi^ it wasn't a matter of being sentenced and bail, bond- MR. RICHARD: The court had recommended ^^^^H Th« government, as I understood, took no position at that point. 126 ONCUSSIFIED but the court had recommended to the Bureau of Prlsons^^^H BY MS. NAUGHTON: Q Was that at the defendant's request? A Oh, yes. But the court endorsed it. The designation by the Bureau of Prisons was that the initial receipt was^^^^^^^^^| which is, I think, one step up in security fromi The purpose of the meeting, I guess, as articulated by Colonel North, was to discuss! Then Colonel North, supported by the general, began also indicating that ^^^^^^^Hwas a friend of the govern- ment — the U.S. government --had helped immeasurably the military. Had helped U.S. forces, was always available. Again, very ambiguous, no specifics, l^it he was always ready to assist us. A I always assumed but I always thought it was 127 _ 1 2 3 4 5 6 7 8 9 10 ^n 12 13 14 15 16 17 18 19 20 21 22 23 24 ' C Sutn. N E 25 iifimim Q Well, yeah, but did they ever refer to him in particular — A Particular function, responsibility? I don't believe so. The general just indicated to us that he was helpful in accommodating our military. So this became the theme, and it was a theme that North was articulating, and the general was supporting tt. Dewey Clarridge concurred. And what was probably the most surprising was Elliott Abrams now concurred that we should do what we can for this man, which, I must confess, I saw as a change in ^^Xl State Department position. In all fairness to Mr. Abrams, he indicated that he had to leave for another meeting. He got up, but his parting remarks were, 'We should do what we can to accommodate this man." And then he left the meeting. I was asked what can be done for this man, and I basically said, "Look. His defense counsel can file motions to reduce. He's always free to apply for some immediate parole consideration." I'm not sure whether I articulated any other options at that time. Then the issue came up — "Well, can you transfer him Who asked that? UNCLASSIFIED I'm tempted to say North, because Colonel North was 128 jlbl28 £? ^ yilftSSIFlEO doing most of thQ talking. General Gorman was just support- ing. Buck Revel was very quiet, and I felt very much on the defensive in this setting. This was — I just found myself in this situation. I told them — I said, "Look. This appears to me to — anything we do for this man seems to undercut our position that we have taken repeatedly that this man is an inter- national terrorist. This is certainly not consistent with the position we have articulated throughout the course^ of this prosecution that this man is a serious international terrorist and should be treated accordingly." Buck Revel supported that proposition, and the meeting ended up with — "See what you can do about transferring him ^^^ I think I offered, as a possibility, because the mission was to come up with a possible response^^^^^ that conceivably what we could do was offer to brief ^^^^^^^^^^^^ he realize what he's asking for? And maybe he doesn't appreciate fully the mplications of the conduct engaged in by this man. 129 (INCUSSIFIED I told them at the meeting that I would take it back and discuss it with the Department of Justice, and that's where we left it. I think Colonel North remarked that he thought he had enough ] It lasted all of 25 minutes or so. I went back to the department. It's strange — I don't know — 1 don't recall briefing Weld on it. I have to assume he was in place at the time. He came in about this time. But I talked to Steve Trott, and he said he didn't have any trouble with sending I Q Had Trott indicated to you that he had had a sinilar meeting with Colonel North? A Not at that time. Subsequently, more recently he had informed me of the fact that there was an earlier meeting. I was not aware of that at the time. I'm not sure of the timing here. I did speak to ^^^^^Band told him about the meeting and asked him his views on sending him to^^^^^ and. he had no trouble with that. It's the mood — the sentencing on_ the^r^eque^t^o jo^o_ ^^^H, and he had no trouble wit mcing on the request to qo to "4!NIllASSlflEll] 82-732 0-88-6 130 uNcussra I talked to, I believe, John Martin. He had no major problems, as I recall. And I got back to Weld, and he told me to call Norm Carlson, head of the Bureau of Prisons — MR. McGOUGH: He told you to call Norm Carlson? MR. RICHARD: Yes. And why I say that — if I may drop a footnote — I had mentioned — when Steve Trott said that to me, I said, "The last time I called Norm Carlson and arranged for a transfer of a prisoner who had begun cooperating" — I transferred him from a medium-security facility to a minimum-security facility — "the guy absconded within a week." So I told Steve, "I'm not sure whether my credibility is very high with Norm Carlson. " So Steve Trott said, "Well, tell him if he has problems with it to have Norm Carlson call me." So that was the gist of the conversation. But I called Norm Carlson, and as I recall, he had no problem with it, and as far as I know, the man was transferred. We never, as far as I know, went down and^^^^^^ And that's about where we are, as far as I know. BY MS. NAUGHTON: UNCLASSIHED Did you ever get back to the NSC or State Depart- 131 Jlbl31 UNCIASSIRED '*' mant? A No. I didn't. Excuse me. There was one other aspect In this narrative I didn't include. I think right before the sentencing I received a call from Judge Sofaer over at State. He had been contacted by, the^^^^^^^^^^^^^^^^^^^^Hof the Department of Defense^^^^^^^^^H I don't recall the who wanted also to Interject consideration for^^H This, I believe, was prior to sentencing. For some reason, the individual couldn't reach anybody within the department of moment, and Judge Sofaer asked me if I would talk to him. I did. And I basically articulated what was our position with respect to providing any consideration ^^^^^^^^^H That was it. Q You never heard from hin again? A No. He was just making a very strong pitch for consideration. That was probably the most official DOD presentation that I had received during this whole process . MR. McGOUGH: Do you remember who it was that Sofaer was speaking for? MR. RICHARD: Sofaer-^he called me just to ask that I call this individual. MR. McGOUGH: But I mean who the individual was ofaer — he called me just ONCLASSIHED 132 jlbl32 ^ ^ M7 C Sam. N.E. ONOLASSIFIED that you were supposed to call? MR. RICHARD: He was head of the J for DOD. BY MS. NAUGHTON: Q Did he Indicate either where he had gotten his information or what his connection was with] A I never received from any source specifics other than a friend of the government — a friend of the United States or another government. Q Just for the record , ^^^^B-do you know what security facility it is? Can you just describe it for the record? A Well, it's a minimum- security facility. there are perimeter security arrangements. MR. McGOUGH: Let me show—mark this as Exhibit 7. [The document referred to was marked for identifi- cation as Richard Deposition Exhibit No. 7.) MR. McGOUGH: They appear to be a couple of 133 UNCUSSIFIED transmittal slips. The top one — both of them appear to be dated October 2. And is that your handwriting at the top of the first one? MR. RICHARD: That's correct. EXAMINATION BY COUNSEL FOR THE SENATE SELECT COMMITTEE BY MR. MCGOUGH: Q And for the record, would you read — it's dated 10/3/86, and %rauld you read that for the record? A "Steve Trott, according to Jim Michel, agreed to briefing. Verified SST"— that's Steve Trott — "send the items," which I assume refers to — that we were authorized to send the teletype. Do you want me to read the — Q No, no. It's not necessary to read the text. But the teletype that it refers to from Abraros was to go to whom? A If I'm not mistaken, it was a teletype responding There was a communication — I — whether it was from^^^^^^^^^^^Bor Elliott Abrams I don't recall. Q How did this fit in time-wise with your meeting with North and Abrams in that event? A The communication? Q This transmittal slip — October 2 — October 3. A I assume that the meeting occurred, the cable was prepared, sent it over to John Martin or he got it from — did 134 UNCLASSIHED 1 sand it over? They weren't aware of this — at the time when they were reviewing a cable of the developments — my proposal, for example, we^^^^^^^^^^^^^^^and the Steve Trott — agreed that that could be something we could do They weren't aware that it had been accomplished to send them to Abrams . Q So by this time there had already been a decision made to intervene with Norm Carlson? A Yes. I spoke to — this is on the 3rd — on the 3rd, my notes suggest that I called Norm Carlson. Now, I'm not sure when physically the man was moved fron Q But the letter and teletype from Mr. Abrams appeared to indicate that Justice had intervened on s behalf and recommended that he be sent to] So that the draft that was sent over on October 2 would have stated that Justice had in fact intervened. A I'm not sure whether it was put in terms of intervention as opposed to — we have agreed to transfer the man or the man is being transferred for convenience of the I'd have to — I'm not sure it was couched in terms of intervention. MR. McGOUGH: What time — do you have a restriction in the evening? ave to — I'm not sure it » UNCUSSIFIED jlbl35 _ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 I CO., MC ONCLASSm ' C Stren. NE. MR. RICHARD: No. MR. McGOUGH: I think I've got maybe another hour or so. MR. RICHARD: I just would like to finish today, but I'm prepared to go as long as you want tonight. MR. McGOUGH: Do you need a break? MS. NAUGHTON: I would like a break. MR. McGOUGH: Why don't we do it now? (Recess] MR. McGOUGH: Okay. Let's get back on the record and turn, if we could, to the Evans prosecution — the Souther District of New York. BY MR. McGOUGH: Q Prior to the revelations in November of '86 about the Iranian initiative, were the defendants in the Evans case alleging a government authorization or government policy defense to their prosecution? A I'm probably the wrong one to ask that question of. My understanding was that they had consistently maintained-- at least with respect to the Iranian transaction8--government authorization. But I would suggest you verify that directly with the Southern District of New York. Q What, if any, authority, supervision, or review did you exercise over the Evans prosecution^ A Well, I had worked with the Southern District" of' 136 jlbl36 CO _ 1 2 3 4 5 6 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 ONCUSSIFIED )fl7 C Scrro. N E New York in terms of their apprehension. The individuals had been lured, if you will, to Bermuda, and it was a question of how to accomplish their arrival in the United States when we have to go through an extradition proceeding which not only would be cumbersome but could pose some problems in terms of the existing treaty and what have you. Our efforts were designed to see if we could arrange for iaipCttirion to the United States . Q Were you involved in the pre-lndictment stage of thafcase at all? A I don't believe in a substantive way. I think I was aware that it was coming down — that there was this ] pending operation. But I certainly wasn't dealing in substance with the Southern District of New York on how to bring it down. Q Prior to the disclosures about the Iranian Ini- tiative, is it fair to say that the case did not — strike that. After the disclosures about the Iranian initiative, did the case draw more of your attention as it related to their defense of governmental authorization? A Well, the case had that particular interest to me because of what I'll call the tsraeli ronnection. And I have been working quite closely on a variety of cases impacting on j the government of Israel-^-or potentially impacting or i . D C JOOOJ 137 jlbl37 UNCLASSIFIED ••^^ 20 •^C 22 mxai m po mtiQ co.. hc. >07 C Stnn. N E 25 Wuhxiroa. C 20002 involving the government of Israel In that regard, this case was of interest because, if I recall correctly, several of the defendants purportedly had priot israeli military affiliation. MS. NAUGHTON: Could we step back again? Could you tell us what the indictment was and what the defendants were charging? I believe there 17 defendants. MR. RICHARD: That's correct. Not all of them have been apprehended. There are a series of — MR. McGOUGH: Has the indictment been unsealed as to all of them, or do you know if they remain sealed? MR. RICHARD: I believe that it is unsealed as to all of them. It's been a while since I looked at the indictment, but what we're dealing with essentially are five conspiracies to illegally export substantial arms without requisite licenses . The arms were going to a variety of — or intended to go to a variety of foreign countries, including Iran, but not limited to Iran. There were other countries, I believe, that also were intended a«d users fer some of the conspiracy. So that what you regard as the Evans conspiracy, I think, is only a portion of the total case. MS. NAUGHTON: Did any arms actually get shipped? MR. RICHARD: I do not believe that anything 138 vmssim arrived . Is that responsive to your question? MS. NAUGHTON! That's fine. It's mostly for the record, not my curiosity. MR. McGOUGH: We get so used to speaking about these things as terms — I think you're right. We need a little bit of background. BY MR. McGOUGH: Q You were talking about the Israeli aspect. A You asked about — my initial interest or focus of the case was in the context of that issue, because I have been, as I indicated, heavily involved in a variety of cases impacting on- Israel Q Can you put a time frame on that issue in the case? A I believe in April of '86, if I'm not mistaken, was the time when it was brought dovm, if you will — the arrests were made and what have you. It was several months, as I recall, trying to arrange for their entry into the United States. But the case was--coinplaints were filed, I believe, in about April of '86. Q Now, after the disclosure of the Iranian arms initiative, there were intensified efforts by defense counsel to raise the government authorization of defense, if we can call it that. And when did it first come to your attention that these had been connected somehow--these defenses had jlbl39 2 4 5 6 7 ^ ONCIASSIFIEO been connected with the Iranian arms sale? A Well, I think from the start of the public revela- tions, which I guess were beginning in Novembervof the governmental initiative, the defendants in the Evans case began citing this as further justification for what they were asserting all along--was essentially government authorization or belief that there was going to be government authorization. If I'm not mistaken, there was no suggestion that they had the government authorization, but they had reason to believe a they would havefat the time of the exportation. There came a point in time, as I understood it, where the court — Judge Sand in New York — was making inquiry into whether there was a connection between the authorized initiative and that which was before the court in New York. And there had been previous representations, if I'm not mistaken, made by the Southern District of New York to the court that inquiries to appropriate federal agencies had r«T<ealed that the activities embraced by the indictment were in fact not authorized. Q Let me stop you there for a second. Were you involved in those original inquiries to the various agencies? A No. Q Did you coordinate them? ] A No. I believe that the Southern District either ONCUSSIRED 140 jlbl40 10 11 12 13 14 15 16 17 18 20 21 22 23 24 DNMXIFe directly went to those agencies or worked through our internal security section to secure the information from the relevant agencies. Q And there came a time in or about November of '86 when the judge wanted something more in the way of a repre- sentation from DOJ. A Well, here it was a representation— thaA wanted information as to whether there was a connection between the mjidLUoad matter and the authorized government conduct, which by that time was becoming publicly known and acknowledged. As I recall, during this period I had been in touch with Rudy Giuliani", the U.S. attorney, and his senior staff; Denison Young; and, I think, S p a ni rdo Romano as well as on occasion talking directly to the assistant. They telefaxed, I think, to me a proposed representation that they were suggesting be made to the court. MR. McGOUGH: Let's mark this as an exhibit. This ia Deposition Exhibit 8. My copy is mis-paginated. Is yours? MR. RICHARD: ¥^i. No, I'm all right. [The document referred to was marked for identifi cation as Richard Deposition Exhibit No. 8.) BY MR. McGOUGH: Q Referring to Deposition Exhibit 8, is that the telefaxed proposal or an affi I'CLASSIFIED 141 jlbl41 _ 1 2 3 4 5 6 7 8 9 10 11 13 14 15 16 17 18 19 20 21 22 23 24 MO CO.. ne. E. 25 smssm With some handwritten interlineations on it. Yes. And that would be your handwriting. Part of it is. Part of it I believe is Bill Q A Q A No. Weld's. Q Now, this would have been transmitted on November 14, 1986. Is that right? A That's the date reflected on the exhibit. Q What steps did you take when you got this? A Well, as I recall, I had earlier alerted Bill Weld to the fact that this issue was facing the department and ■ that I believe Bill Weld had informed me that the attorney general was going to certify that there was no connection between the two cases . Q This was before November 14? A I believe, if I'm not mistaken, that it was before the receipt of the proposed Southern District language. Q Which is dated November 14? A Which is dated November 14. What I'm suggesting is in point of time it may have occurred on the 14th but prior to the receipt of the telefax. I told Bill Weld that I thought that that was a terrible error. Q What was the terrible error?| A To have the attorney general certify that there was UNCLASSIFIED 142 isamsim ' C Sum. N E •hinroo. D C 20002 no connection, because, quite candidly, as I evaluated the matter, I couldn't understand how anybody at that point in time would be in a position to certify that there was no connection. Setting aside the ambiguity of what a connection means — and I'm not sure to this day I know when you say there is no connection what you are asserting — it appeared to me that unless one had the most intimate knowledge of both sides of the equation — to wit, the Evans case and all of its nuances--as well as the Iran initiative along with all of its nuances, how could anyone draw a conclusion that there was no connection? And I expressed this concern, I think, very strongly to Bill Weld, because I thought we were going down a path where inevitably we would be — the defendants would assert that we were disingenuous with our certification if fetors - lightest arguable connection showed up down the road. And I was concerned about that. I expressed it first to Bill Weld. I believe he agreed with me. I think he raised it with Steve Trott. we then — if I recall the sequence — we got the telefax, we went over it, changed some aspects, and again sent it forward. And I was again strongly urging that it not be made. Q And when you say "sent it forward", you mean sent a draft or a revision of tpis. teJ-etyoeact^S^^fiflrward to the attorney general. 143 _ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 16 17 18 19 20 21 22 23 24 ONClASSIflEO A Well, I can only say that as far as I know, it went up to Steve Trott. I have no knowledge of whether the attorney general literally saw this proposed teletype — this telex. Q But at the time you sent this forward, Mr. Trott, as you understood it, was aware of your reservations and concerns? A I don't believe I expressed them directly to him, but I think Bill Weld had let him know my feelings. MS. NAUGHTON: If I can interrupt you for a second. I missed whose idea or insistence or whatever it was to have the AG actually certify this as opposed to some other official. MR. RICHARD: Well, that was the point. I think the Southern District had proposed it as their be s t desire. MS. NAUGHTON: Had they proposed this to you? MR. RICHARD: My recollection is that they had said that's what they wanted — was the attorney general to certify. And I believe that's the way I interpreted it — that they wanted the attorney general himself to certify it. And as it related to me, it was that there was a willingness to make such a certification. MR. McGOUGH: Was that related to you by Mr. Weld MR. RICHARD: Yes EXAMINATION BY COUNSEL FOR THE HOUSE SELECT UNCLASSIFIED 144 UNCUSSIFIED 1 2 3 4 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 .. MC 25 COMMITTEE BY MS. NAUGHTON: Q So Weld got back to the attorney general, and he said he was willing to make such a certification? A ¥ee*»>^ If I'm not mistaken, on this particular day when the issue was resolved, there was a question. There were two matters arising from active litigation in the field--the Evans and a matter on the West Coast, where--I think it was either San Diego or L.A. had a case — it was L.A. — before Judge Wilson. And Judge Wilson was inquiring as to the government's intent in light of the public revelations of the Iran initiative. The judge in that case had a convicted defendant who was moving to set aside a conviction or a sentence. He had been convicted for allegedly — not allegedly — but for exporting illegally to Iran certain proscribed materials. And the judge, in response to that motion, was asking the prosecuting U.S. attorney for certain information regarding the government's intended way to proceed in light of these revelations. So we — and the USA out there had three questions that he was seeking the answer to from the depart- ment. So both the Evans and this other~clse went upstairs That is to say, I believe it was handled at an executive 145 jlbl45 ^-*J «ms«fl MAUI KVOKTMO CO.. MC. m^ meeting which the top management of the department holds every morning. And I think it was taken up at that point in time. And I believe that this was done prior to the receipt of this actual proposal. There was--if I'm not mistaken--there was nothing written on the table, if you will, at the time that the initial decisions were made. After the morning meeting, which takes place fairly early in the morning, if my memory serves me correctly. Bill Weld came back with responses for L.A. and a response — or at least a way of proceeding--in the Evans matter. And it was in that context, if I'm not mistaken in my sequence of events, that it was conveyed to me that the attorney general was prepared to make the certification. And that's where the matter stood. And later that day, which was the 14th--a Friday--I had occasion to be with Steve Trott, and I believe it was in connection with another case — the Pollard case--there were aoae developments on that — where Steve Trott called the attorney general and asked me to accompany him to see the attorney general on that matter. We briefed the attorney general on that matter, and — maybe somewhat presumptuously of me — I said, "Mr. Attorney General, I want to raise the issue of the Evans case with you because I think it '-a a horrendous mistake that's 146 WUSSIflfO about to be made." And I quickly articulated the reasons why I did not think that the department should make this kind of certification at this point in time. Apparently — and this I guess you'd have to ask him — but my impression of his reaction was that he had by this time — he was not going to make that certification, because he quickly said — led me to believe that he was going to take it up the next day — Saturday — with the National Security Council. Now, I'm not sure whether he said National Security Council or Admiral Poindexter. And that's where the matter stood. Q Did he say — obviously — correct me if I'm wrong-- your pitch is someone's got to know the full details of that and — of the Evans case and the U.S. -sponsored Iran initiative in order to make such a certification. A If I may interrupt, the argument I presented to him was a simple argument, and that is that you just don't know all the proprietaries that may have been used or contemplated by either side of the equation. And until you at least know that, you're walking into a no-man's land in terms of connections between the two I hope you appreciate--at this point in time, I don't think I appreciated that the attorney general had any personal involvement in the Iran authorized initiative. So I assumed he had no knowledge on both sides of the equation. lO-man s iana xn terms oi UNCLASSIFIED 147 IMIFIEO Q Well, that's my question. Did he impart to you any — either any knowledge of it or did he tell you that someone was looking into the Iranian — the U.S. -sponsored Iranian initiative? A No, he just — he just basically said without commenting on substance that it was going to be taken up with the — either with Admiral Poindexter or the NSC the next day. EXAMINATION BY COUNSEL FOR THE SENATE SELECT COMMITTEE BY MR. McGOUGH: Q How did you understand that would move in the direction of solving the problem? A Well, for one, I felt somewhat relieved because the — it wouldn't be the Department of Justice making the certification. It was the National Security Council, who I assumed was intimately familiar with at least the Iran initiative. They would be in a far better position than the Department of Justice to come up with this broad certifi- cation. Q But only from the Iran initiative side of the equation, which still had much less to do with the Evans case. A I'm still troubled by that fact. Q So Attorney General Meese Wf_aoiig i^o_g£ th? NSC and Admiral Poindexter on the--case. A I'm not sure whether he said he would go, but that 148 iifimim 1 matter would be taken up on — 2 Q What was the next word you were going to say? 3 A Monday, I believe, which would have been, I guess, 4 the 17th. 5 I think I probably either was out of town or late 6 because by that time there was agreement on a certification 7 to be offered to the Southern District of New York in 8 response to Judge Sand's request. I think I learned of that 9 after the fact. 10 I have seen some notations that indicate that the 11 certification finally was devised was in fact communicated to 12 the Southern District by Bill Weld directly. 13 MS. NAUGHTON: Did you have any part in drafting 14 that? 15 MR. RICHARD: I had commented on the draft that 16 came in from the Southern District without changing the 17 critical point. What came in from the Southern District was 18 not focused on the attorney general, though, but rather the 19 Department of Justice, which also was of more comfort because 20 originally I thought the attorney general personally was 21 going to certify. 2 2 BY MR. McGOUGH: 2 3 Q So you run it back on Monday to find that there was 24 some resolution? MC. 2 5 A Yes. Mmm 149 _ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 24 >07 C Su»»i N E 25 Vtlhiufsxi. C I0C02 DNCWSWO Q Did you attempt to determine — or did you determine how that resolution had met your concerns the week before--in other words, whether someone had in fact discovered once and for all that there was no connection. A Well, I was confident somebody satisfied themselves that under some interpretation of the word connection that there was none. Q Did you know who had done that? A I thought it was Admiral Poindexter, who was in charge of making the final judgment to the Department of Justice. Whether he tasked anybody at the NSC, I cannot say. Q But the certification went out from Mr. Weld to the Southern District. A It was transmitted by Mr. Weld, but it was from the Department of Justice and made reference to the consultation with, I think, the NSC. Q Were you confident that whoever was acting on b«half of the Department Justice in that capacity had sufficient understanding of the Evans case? A Was I confident? Q To make that representation^ A I was concerned, only because I was concerned that someone would read connection extremely broadly. And I wasn't confident that, given the broadest interpretation of what Judge Sand was seeking, whether there was anybody in UNCIASSIRED 150 UNCLASSIFIED 1 Washington certainly familiar enough with the Evans case to 2 assert that there — with conf idence--that there was no 3 connection. 4 Q Well, I guess what I'm driving at is when you saw 5 on Monday that Weld had made this representation for cer- 6 tification — 7 A If I may just interrupt you. 8 Q Sure. 9 A Weld didn't make the certification, weld trans- 10 mitted it to the Southern District. 11 Q When you saw on Monday that it had been transmitted 12 to the department, were you still uncomfortable with the 13 transmittal or by that time — 14 A Well, I'm concerned because it appears to me that 15 it's an area of potential problems. This was a certification 16 that was generated in good faith, but I was concerned without 17 some clarification, simply because I just don't know what the 18 word connection means in this context. 19 You have overlapping equipment, for example. If I 20 recall correctly, some of the equipment in the Evans case 21 consisted of TOW missiles. Is that a connection? If they 22 used the same certification mechanism, is that a sufficient 23 connection? 24 MS. NAUGHTON: Were you_ aware of the^ Khashoggi 25 connection with the Evans case? UNCLASSIFIED 151 JlblSl g Mujii imt m ita eo.. mc. ONCUSSIflED MR. RICHARD: I was aware that— when you say connection—I was aware that Mr. Evans had a prior relation- ship with Adnan Khashoggi. we haven't determined whether that relationship extends to the operations involved in the Evans case. But there was history of a proprietal relation- ship. All of those were concerns of mine. BY MR. McGOUGH: Q Were you aware at that point that Mr. Khashoggi was somehow involved in the Iranian initiative? A I can't place it in time. I just — if nothing else, in the abstract, I saw this as a troublesome area that either should have been better articulated as to what the court was seeking by way of assurances or at least some more systematic inquiry should be accomplished before we made those represen- tations. Q As of Monday the 17th, did you express those concerns — those continued concerns to Mr. Weld or anyone else? A Well, I don't recall afterwards expressing the same degree of concern. I was greatly relieved that the department had at least gone out to the. NSC, who I understood had the information, at least on the authorized Iranian initiative and had sought their representations— affirmative representa- tions to the extent that they were in a position to make them--that no, they were aware of no connection. This 152 23 C24 >07CS<rtn. NE. 25 TMhiiiftoo. D C 20002 certainly alleviated a portion of my concerns. I'm not sure that I continued to articulate ongoing concerns on this point. Q Did you feel that you had been cut out of the situation? A No, not at all. Q On the 14th you screwed up your courage and raised this with the attorney general sua sponte, and then on the 17th you came back and found out that essentially that while the solution was a little bit better, it still didn't solve the problem. Did you feel — did you follow up any more with it? A No. No, I didn't. I had, I think, expressed concern over a period of time — I just can't put it in time-- in conversations with Denison Young about this problem. Q After Monday the 17th, when you learned — A Excuse me. If I may interject. My concern continues to be there only because now you have independent counsel generating information on the Iran initiative that is not being shared with the Southern District of New York, to my knowledge. So that now we're — at least as an abstract proposition — in the difficult position of standing by our representation but not privy to possibly new facts developed by the independent counsel that wf undercut^ theJL^^ regresenta^ tion. This concern I have also articulatec 153 jibl53 _ 1 2 3 4 5 6 7 8 9 10 11 12 13 '9fi\. 1 20 ^ MafivoKTwaco •It >07CSa«i, NE wussm No, but I — I just want to get at the facts. That's right. So basically it's in the nature of a pleading to MS. NAUGHTON: Can I ask just about the representa- tion? MR. RICHARD: Sure. EXAMINATION BY COUNSEL FOR THE HOUSE SELECT COMMITTEE BY MS. NAUGHTON: Q First of all, this is not an affidavit that someone signed. A Q A Q the court. A I don't know whether it was just a statement on the record or by — in a particular pleading. I mean, the department would not, .*« my judgment, tolerate erroneous representations to the court. Q Oh, no. That's not my point. My point is this: were this to be challenged--and what I'm asking is did this go through your mind as well — not just that that representation might be erroneous but that someday someone may actually have to testify at a hearing or a trial if either connection was found. And did you--did it concern you that this person might have to be the attorney general or Admiral Poindexter or someone of that stature? 154 . C 20002 WMsm A Well, yes it did certainly concern me. This was one of the reasons why I suggested that this — initially a certification, as I understood, coming directly from the attorney general was crazy because it exposed him as a potential witness. This was one of the reasons for initially- objecting. Q Did you articulate that concern to the attorney general? A No. Q Did you articulate it to Mr. Weld? A Yes. The question — you made a statement with respect to the concern. I was concerned about raising it with the attorney general. It was just in terms of the propriety of it — I mean, we were not there discussing the Evans case, and it was something that I had raised with my immediate superiors. It was in the context of deviating from the chain of conanand that I saw myself, if you will, subject to some criticism, because I had raised it with Bill Weld previously. I knew he had taken it up directly with Steve Trott, and in that regard, for me to jump over them and take it--you know, mention my concerns directly to the attorney general was just outside the normal chain of command. EXAMINATION BY COUNSEL JOJ iHf:.,fi{aU^XE SELECT COMMITTEE IMM 155 jlbl55 ^ ^ Mftun nratmta co.. mc. «)7CSOTn. NE 25 Vaahuidon. D C 20002 Mmsm BY MR. MCGOUGH: Q We're now coming up to the fact-finding weekend, as its become known, starting — on the 20th, 21st — in that area. Did you have any further contact specifically with the Evans issue prior to the weekend of the weekend of the 21st, 22nd, and 23rd? I mean, did it come up again at any meetings that you attended? Did you raise it again with anyone that you can recall? A No, not the certification issue. I spoke regularly with the Southern District of New York on the Evans case as well as other cases, and I would not be surprised if the Evans case came up. But in terms of going higher within the department, I don't recall any further meetings that we had. Q Were you aware that Mr. Weld raised the issue at the staff meeting on the 21at? A Which is? Q Friday — the issue of the — whether the Criminal Division should be involved. It came up, as I believe as Mr. Weld's deposition, which has been released, indicated in the context of the Criminal Division becoming involved in the Iranian initiative side of the inquiry so that one person or at least one division would have all the facts in both the Evans situation and the Iranian initiative — exactly the point you were raising before that someone had to understand both 156 ■uun nronnta co.. mc. SOJCStxm. NE 25 VututfVXl. C 20002 liNcussra sides of the equation. Were you aware that Mr. Weld raised that issue at the staff meeting on Friday morning the 21st? A No. Are you sure it's the 21st and not the 14th? Q The information read that it's the 21st. A No. In answer to your question, I'm not aware. If this is subsequent to the resolution of the Evans certifica- tion, then the answer to your question is no. I'm not sure-- I was not aware that this became a new issue a week later. Q Were you aware that the attorney general spoke to Mr. Weld on the 24th? That was a conversation where the attorney general said it's not accidental — or allegedly said it's not accidental that the Criminal Division has been kept out of this. There's a reason for it. Mr. Weld made the statement — made a statement about water spilling on the attorney general . A No, I was not aware of that conversation. EXAMINATION BY COUNSEL FOR THE HOUSE SELECT COMMITTEE BY MS. NAUGHTON: Have you read mmmw Q It's my recollection — please correct me if I'm wrong; actually I think I have it — that he stated that you were present in his office when he received the call from the 157 jlbl57 - 1 ^1 18 19 ^ ^ ^^ 17 C Sort. N E eo.,^^ ONCLASSinED attorney general . A I may have — on the 20? Q On the 24th. This would be Monday morning at approximately 9:55 — right before 10:00 o'clock. A I may have been in his office when he received the call. My recollection is the first time I passed with anything or^given any information regarding this issue is the 25th. MR. McGOUGH: Now, this is — when you talk about this issue — we're not talking about purely — we're not purely talking about the Iranian initiative. What we're talking about is the Evans — the interplay between the Evans case and the Iranian initiative. MR. RICHARD: I must confess. I have read the Weld interview on this point, and I wasn't sure what was being referred to, whether it was the Evans case or the Iran initiative . BY MS. NAUGHTON: Q If I can for the record — page 22 is where he begins a discussion of this. And the question was: "Q On the 24th, did the attorney general call you in regard to this subject? "A Yes . "Q Do you recall when that was? "A Well, it was during a meeting I was having with my 158 jlbl58 *-<_f 19 S ONCLASSIFIED deputies. And those are often at 10:00 or at 10:30 a.m., so I would say it was between 10:00 and 11:00 a.m." And then he goes on to describe the call which Mr. McGough just alluded to. Do you recall either listening to Weld's portion of that conversation or discussing the contents of that conver- sation after he hung up? A No, I don't. We have regular deputies' meetings. Generally they do follow on the heels of his meetings with the senior management. I don't recall the Evans issue still being on the front burner at that time. We had — I am not sure of the arguments articulated by Bill Weld to the attorney general with respect to the Evans certification. I don't know whether he referred to questions of proprietaries or both sides of the equation or what have you. I'm just not sure how we phrased it to the attorney general . MR. McGOUGH: Do you recall ever being present when Mr. Weld said over the phone to the attorney general something to the effect that "I don't think you should try to carry too much water on this thing. Some of it may spill on you"? MR. RICHARD: I don't recall the specific comment. It is the type of comment that Bill Weld would make. MR. McGOUGH: But you don't recall being present 159 UNCUSSIFIED when it was made. BY MS. NAUGHTON: Q Do you recall him ever alluding to or expressing a concern that the attorney general was acting like a gumshoe? A Well, the next day — and when you're talking — Q The 25th? A — the 25th — that there are a lot of discussions and comments that I'm privy to--but not on the 24th. Q I noticed you brought some of your calendars here. Could you please check the 24th? Would that indicate to you whether or not you had a meeting with Weld and at what time? A I don't have my calendars here. These are only just little calendars. Q I believe those were provided to the committee. I just don't have them with me. A I had — beginning on the — I think it was the 25th — I began trying, to the best of my discipline and ability, to ka«p a log of some sort. But that began on the 25th. I have nothing beginning on the 24th other than following public media disclosures regarding the Iran initiative. EXAMINATION BY COUNSEL FOR THE SENATE SELECT COMMITTEE BY MR. MCGOUGH: UNCLASSIFIED Let me — in that vein — let me take us back again a 160 _ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 a CO.. MC. 25 ONCUSSIflEO little bit. And I want to talk about public disclosures of the Iranian initiative. Like most people in Washington, I suppose that you were at least picking up on them now and again and were aware that this was a breaking sort of story. A Oh, yes. Very much so. Q Did there come a time prior to November 25th when you began to take a professional interest in the Iranian — allegations about the Iranian initiative? Did there come a time when you began to consider whether or not there were possible criminal violations involved in the activities that were being reported in the paper and if so, what if any role the Department of Justice would be playing in those. A Well, I was very much concerned about them — the initiative, in particular the impact on potential— well, on cases both concluded and pending. Q But setting aside existing cases — in other words, a*ttlng aside the impact of the initiative on existing caaea — did you begin to consider whether the activities that were being alleged to have occurred in the initiative itself may have transgressed criminal statutes? MR. RICHARD: Can we go off? [Recess] MR. McGOUGH: Let's go back on the_record. BY MR. McGOUGH: 's go back on the record. IINCUSSIFIED 161 ONCUSSIRED Q Mr. Richard, is it fair to say that during the period when you were reading about the Iranian initiative leading up to November 25th that in your 0'.^n mind you were speculating about the procedures under which these sales might have been made and the legal requirements that might have applied to them? A Yes. I was very interested in how these transfers were accomplished. Q But did you discuss those speculations--to the best of your recollection — with anyone else in the department? A No, I was just following media revelations as they occurred. And did you do any independent investigation to determine whether, in fact, there were violations of those procedures or requirements? A No. Q When was the first time that you initiated those sorts of discussions or involved yourself in those sorts of discussions or analyses? A As I recall, November 25th, I think, was following the attorney general's press conference and the revelations_ of diversion of monies to the contras I was with Bill Weld in his office discussing the revelations when we were asked to proceed--! think first to Steve Trott's office but ultimately ended up in Chuck jnce ana tne revelations UNCLASSIFIED 82-732 0-88-7 162 jlbl62 1 ^ _ HC. 507 C Soett. N i UNWSSIHED Cooper's office, where we were asked to review the situation and give a preliminary assessment of possible criminal statutes that might be implicated. Chuck Cooper was there along with--I think it was a staffer for Mr. Cooper-- John McGuinness, I think his name was. And we were given probably no more than a five-minute factual run-down by Mr. Cooper, and he handed out what purported to be a chronology — a classified chronology. EXAMINATION BY COUNSEL FOR THE HOUSE SELECT COMMITTEE BY MS. NAUGHTON: Q Do you recall how long it was? A It was several pages. Q Was it like a narrative chronology or just a date? A I believe it was just dates. There was a slug--a date, an event, a date, an event. I recall that Mr. Cooper gave it to us to look at but indicated that there was some question as to its accuracy. We really didn't have much time, as I recall, to go over the chronology, relying on the presentation of Chuck Cooper and our appreciation of the facts as discussed both in the media and in the attorney general's press conference. We opined what criminal statutes might be involved or that could be involved. And at that point the attorney general convened a meeting which I did not attend; i was not 163 jlbl63 _ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 miMsim 163 invited to. Q Excuse me. Could you give us a time estimate on that first meeting in Cooper's office? A It was late afternoon. I would venture to say 4:30, 5:00 o'clock at night. The meeting with the attorney general occurred probably around 6:00 o'clock. I remained outside the attorney general's office. I had — was talking to a U.S. attorney who — there were press reports indicating an arrest with an Iranian connection, and I was trying to find out some details about that which turned out to be not the case. My recollection is that the meeting with the attorney general lasted seemingly about a half hour or an hour and then broke up. MR. McGOUGH: Given the facts as you understood them at that point, what criminal violations did you speculate might have been committed? MR. RICHARD: Well, there was a whole »4rO««h of potential statutes, depending on how the transaction was in fact structured or what was done to accomplish it. And there was a lot of assumptions, if you will. How was the money transported? what Customs violations were triggered as a result of attempting to move currency without declarations? Did that occur? Were bribes paid to foreign officials? I mean, it just went on and on, all based on "what if". 164 jlbl64 ^^ 19 C2^ 20 ^ 22 24 JOT C SoTit. N E 2 5 Wuhmftoa. O C J0002 UNCLASSIFIED And of course nobody at that time had the answers to that. So you really just didn't know. BY MS. NAUGHTON: Q If you can recall, what did Mr. Cooper tell you during the meeting in the late afternoon of November 25th about the November '86 HAWK shipment — how it came about? A I'm not sure. I took some scratch notes. I don't know whether they reflect that kind of specificity. Q But what you have in your notes is "November '85-- IE HAWK missiles transferred but ultimately returned." A That would have to have come from Mr. Cooper. Q Do you know if — do you recall if he said anything else about that other than that they were shipped and they were returned? A I assume I put it down there only because I thought it might be of some significance to the analysis of what potential criminal statutes might have been triggered. It was a very superficial factual presentation, and I think, if I'm not mistaken, it was interrupted by one or two telephone calls from other high-ranking officials to Mr. Cooper giving him more details — I think State Department officials. MR. McGOUGH: Was it your general conclusion that the chances that criminal statutes were transgressed were remote, likely, 50/507 Could you — what was your feeling 165 ONCUSSIflED coming out of the meeting? That it was a remote possibility that there were crimes committed or that it was a likely possibility or did you have a feeling at that point? MR. RICHARD: My feeling was that it was something that had to be investigated from a criminal point of view-- that there was no way you could easily draw a conclusion that there was no criminality involved without a thorough analysis of what transpired. I was obviously familiar with the identifies of certain of the participants, which made me very skeptical about the integrity of the operation. BY MS. NAUGHTON: Q Who are you talking about? A General Secord, I think, was identified as playing a significant role. I think at that time also Mr. Hakim, Mr. C <lines. Q Did you know Hakim from before? A I knew of him, yes. Q What did you know of him? A That he was a shadowy character that played a financial role in some of the transactions that occurred back during the Wilson inquiry. I don't think we ever made anything, but again he was just a very elusive figure. It just made me--hai^taned m^concefn^^nowing the individuals involved. 166 DNCUSSIfe EXAMINATION BY COUNSEL FOR THE SENATE SELECT COMMITTEE BY MR. McGOUGH: Q Did the meeting with Mr. Cooper conclude with any sort of recommendation or resolution? A Well, I think that — yes, to the extent that there were arguable criminal implications of these transactions. I think Bill Weld and I were categorical in our conclusion on this point. Whether a given statute may be implicated or not was academic. But it was clear that there were potential criminal statutes that were involved, especially with diversion and a lot of questions about whose money was involved and property rights and was there a theft of government property, a misuse of government property — a whole range of issues that came to mind, depending on what the facts ultimately proved to be. Q Was there any consideration or discussion at that point of how the investigation might proceed as a practical matter? A The meeting with Mr. Cooper and Mr. McGuinness? Q Yes. A I don't believe so at all. It wasn't clear that there was going to be an Q Was there any discussion gi ! so at all. It wasn't clear that — "-11HCUSSIF1ED liscussion given to the — was the 167 )07 C Stitn. N E 25 Wuhmttoo. D C 20002 IINCUSSW possibility of destruction of documents discussed? A At that point? Q At that point . A I don't believe so. Q Was there any discussion of the necessity of securing documents or examining documents? A Again, not at that stage. I don't believe so. Q With the conclusion at the meeting with Mr. Cooper on the 25th — did that conclude your role in the matter on the 25th? Did you do anything else that day with regard to that investigation or diversion? A I believe I remained at the department and talked to Bill Weld after the conclusion of his meeting with the attorney general. It's hard for me to identify precisely at what time what was said. When I learned about the role of Mr. Reynolds and Mr. Cooper and the attorney general, I know from the first time I learned about it I expressed concern about it. And I expressed to it to Mr. Weld. Q When did you first learn about that? A I'm tempted to say the 25th — the time that I met with Mr. Cooper. Q By that role, you mean their role in the fact- finding inquiry over the weekend? that's correct. UNCLASSIFIED 168 Wuhmroo. D C 2000! ONCLASSIFIED Q And what concerned you about that? y^ A Well, I saw this as inevitably going toTcriminal inquiry. I just didn't see how it would go in any other direction, ultimately. And there were a variety of issues that gave me concern — one, the fact that these very high-level officials would in fact be witnesses — conceivably fact witnesses — of critical importance to any inquiry; the fact that from an appearance point of view it suggested that in all probability their conclusions would be questioned and their motives examined, their objectivity examined. I just felt that given the political situation--the factual context in which we found it that the department would be best served to get it into a more regularized pattern and, in my experience with these highly charged situations, to assign it to career, experienced prosecutors to commence an appropriate inquiry. And I appreciated many of the counter-arguments of theirs. I felt, on balance, that it would be a mistake. Q It was a mistake to? A To play this role at this level--to have these high-level officials play this role. Q That being the role over the fact-finding weekend. A That's correct. MS. NAUGHTON: Who was making the counter-arguments ^ 169 Ws ^ oirma co.. mc. ..NE 25 C 20002 UNCLASSIFIED MR. RICHARD: Myself, in my own mind. MR. McGOUGH: Like any good lawyer. MR. RICHARD: No, I can appreciate the fact that the attorney general wears at least two hats and that in the context ofTneeds that he has to accumulate the facts. But there, in retrospect, certainly it might have been better served assigning someone to gather these facts and report back to him rather than participate at his own level and the levels of Mr. Reynolds and Mr. Cooper. BY MR. McGOUGH: Q You said that one of your concerns was the appear- ance of a lack of objectivity by Mr. Reynolds, Mr. Cooper, and the attorney general. Did you have any reason to doubt their actual objectivity — that's Mr. Reynolds — any reason to doubt his objectivity? A None whatsoever. No. Q Any reason to doubt his competence to handle the investigation — to handle the fact-finding — the role that was cast for him in the fact-finding weekend? A The role as articulated by the attorney general? No. I had no doubt--question his competence and ability to do that. EXAMINATION BY COUNSEL FOR THE HOUSE SELECT COMMITTEE IINCLASSm 170 liNCUSSIflED BY MS- NAUGHTON: Q As long as we're on Reynolds, can I ask a question? His official title is assistant attorney general to the Civil Rights Division — or at least was at that time. A Except that--I just don't know that for sure, because I know he has assumed other duties as well. Q Okay. That's what I want to ask you about. In terms of the other duties, could you describe to us what you know of those? I'm speaking in terms of the November '86 reference rather than what he's currently working on. A Well, I don't know the timing. But he has assumed the duties of counsellor to the attorney general — that's my understanding — the role Ken Cribbs previously played. Now, when--I can't place it in a point of time in November . Q The attorney general testified that Reynolds was coordinating or somehow working on national security projects — alluded to them and did not elucidate. Do you know what those were? A No, I don't know, but it's quite conceivable that he had such assignments that I wouldn't know. I wouldn't nave a need to know. Q Was he perceived to be tl* °— '1°— VUJ<L number two man at Justice? rNffiM"" 171 _ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 HO CO.. WC. I 25 BNcussre A No, I certainly didn't perceive--I saw him as an individual who appreciated the confidence of the attorney general, who was very interested in a variety of areas and was called upon by the attorney general and others for his counsel and was well-regarded. Again, back to the response — you know, of my concerns. I think I had articulated a question--why can't Mary Lawton's office play a role at some point? MR. McGOUGH: You mean at some point after the 2 5th or some point leading up to the 25th? MR. RICHARD: Why aren't they being utilized? BY MS. NAUGHTON: Q Could you explain for the record what her office is and what her background is? A Well, she is the head of the Office of Intelligence Policy Review and handles all Department of Justice matters relating to implementation of the Foreign Intelligence Surveillance Act and is the principle component responsible for formulating and commenting on national security issues for the Department of Justice. Q And that would include covert findings — covert action findings? A I'm not sure precisely what her role is in that regard, but I do believe she has a role to play in that. Q And could you just give us an idea for the record I include covert iinoings- UNCLASSIFIED 172 IHmFIB how long, as far as you know, that you she has been with the Department of Justice? A Well, she was formerly with our Office of Legal Counsel. She is a well-regarded attorney, has been with the government — must be at least 20 years. She had been with us, I think, for about 15 years, went into the private sector for about three or four, and returned to the department--or returned to government, I think, in about 1980 and assumed her present duties when Richard Willard became head of the Civil Division in approximately 1984, I would venture to say — maybe earlier. Q When she was in the Office of Legal Counsel, do you know, was she — did she involve herself or write any opinions regarding national security matters or intelligence matters? A I believe so. I think at that time there was no Office of Intelligence Policy Review, and I think she was the principle — certainly one of the principle — senior attorneys working in the area for the Office of Legal Counsel at the time. She was also very active in FBI intelligence and undercover operations, commenting on the parameters of those activities. MS. NAUGHTON; Thank you. EXAMINATION BY COUNSEL FOR J^HE .S^liJ^JS^SELECT COMMITTEE COUNSEL FOR THE SENATE SI HASSA 173 WUSSIfJfD BY MR- McGOUGH: Q Let me expand on those questions I asked about Mr. Reynolds in regard to Mr. Cooper and Mr. Richardson. Did you have any reason to question Mr. Cooper's objectivity or his experience — competence to handle the task that had been assigned to him over the fact-finding weekend. A No, not to question his competence. I mean, it was apparent — to me, anyway — that he would be criticized, that it would be regarded as being irregular, as being inappropriate for him to assume what would be perceived by many as an operational role more suited for operational type personnel. And I was concerned that the public would see this as a substitute for a different type of investigation, which would draw the department into controversy. Q How about Mr. Richardson? Same questions. A Mr. Richardson — again, he is an extremely competent attorney. And again, there is no question of competence or if capability. It's a question of given their positions^being misconstrued as to their operational responsibilities to gather this kind of information. Q Do you think that each of the attorneys we've been discussing have the type of experience that you believe might have been desirable to do the type of document analysis-- interviews and analysis^ tha_t^<*as_r^yj.C5d.UJie£ the fact- finding weekend? iMim 174 jlbl74 _ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 ■cBn mpcKvua co.. i «)7 C Scrett. N E WuJunron. O C 20OO2 ONCLASSIFIED A Given their mission, I would say yes. t what concerned me was that their mission would be I mis-perceived. Q How did you see that mission? I mean, you say "given their mission". What do you mean by their mission? A To basically find out what was--had transpired. To determine what has to be done. The trouble is to conduct interviews in this setting and in this context. The concern I've always had is that it would be viewed as the launching of a criminal inquiry by people who normally do not engage in such activities, and thus it would be perceived as being irregular. The fact that the attorney general--tasked by the president or on his own initiative-- seeks to acquire relevant data to find out what has occurred in order to make executive decisions is not inappropriate, in my judgment. But I think this distinction over time would be lost on the public in general. Q Based on what you know about the fact-finding inquiry and the results that evolved over that weekend, was there a point prior to November 25th that you feel the Criminal Division should have been brought in? A Well, it's hard to say. For the purpose as articulated by the attorney general and others that was to be served at that time based on their appreciation of the facts. 175 jlbl75 _ 1 2 3 4 5 6 7 8 «?! 11 12 13 ^14 15 16 17 18 19 20 21 22 23 24 ONCUSSIflED there was no problem. I have no quarrel with what was done. I don't take exception to the notion that we have a confused set of facts. You try to find out what in fact occurred. The difficulty was the information that they generated suggested that what they were involved in may have criminal implications. But it was the very product of their efforts that revealed that. Now we have the question of the ramifications of their activities on a potential criminal inquiry, and all that "hlowfi from that plus--you know, what concerned me was drawing the department's credibility into question publicly. Q On November 26th, do you recall speaking with Mr. Weld from Milwaukee? A tU»tr. 1 had gone out of town for the Thanksgiving holiday, but I had urged before leaving that again the matter be sent to the Criminal Division and assigned to career people. And I periodically called in to Mr. Weld. Q Did you feel that your recommendation was being followed? A At that point it was being considered. There was no resolution, as far as I understood--you know, at that time what was to be done. How any inquiry would be structured and how the department intended to pre stood, was still being consi ."-ICtfflfi Did you ultimately at some point learn that a team 176 mmm of Justice Department attorneys that included Mr. Cooper was going to conduct the follow-up investigation after the 25th? A Well, on the day after Thanksgiving, which was the 27th, I think. Q The 28th. A You're right—the 28th. I think I was informed by Mr. Weld that a decision had been made to send it to the Criminal Division. I think when he told me that on the phone, I suggested that we immediately issue grand jury subpoenas to all the appropriate people at the White House to preserve the record and ensure that everyone was on notice that there was an ongoing criminal investigation and that there would clearly potential obstruction issues if there were destruction or tampering with pertinent records. Q What suggested to you at that point that that sort of precaution was necessary? A Professional experience? I don't know. Q There was no fact that came to your attention between when you were brought into the case on the 25th and your recommendation on the 28th that might have led you to believe that possible — that these steps ought to be taken to prevent destruction of records. A I don't recall any specific fact. It just seemed to me that any destruction or alteration of documents was a 177 107 C Sum, S E Vuhincton. D C mm\m natural concern that we should have. I can't tell you what suggested it to me. Q Do you know what steps were taken--or what was Mr. Weld's response, do you recall? A Well, he told me that the attorney general decided that grand jury should--subpoenas should not be issued, that we can accomplish the same objective I was seeking to accomplish through the sending of letters to relevant, agencies . Q Did you consider that an acceptable alternative? A Acceptable? Well, part of my concern was antici- pating a potential defense of individuals that they weren't aware that there was an ongoing criminal inquiry. And sending to an agency — protect your records--accomplishes a portion of what has to be accomplished to protect and preserve the records . The conveying of knowledge, though, is easily conveyed when someone is specifically hit with a grand jury subpoena for records . Q It was acceptable but didn't totally do everything you wanted — would have liked it to do. A Well, I mean--yes . ,>i4stjny own approach would have been to issue the subpoenas. Q Let me return to what I think — a questiorT that I left dangling a little while ago, and that was did you learn 178 fimssm that a team of Justice Department attorneys that included Mr. Cooper was going to be supervising the investigation on behalf of the department? A When you supervising the investigation--the I don't recall that it was that he was to supervise but rather be part of the criminal investigative team. Q Well, I'll accept that. A No, I mean it wasn't that all of a sudden we were reporting to Cooper — that was not my understanding--but that there was the desire that he participate as part of — a member of the team. Q Did you have any problems with that? A Yes, but they were subsumed by events, because it was clear that — quickly that the way we should be going is through the appointment of an independent counsel. So the notion of constructing a viable in-house investigative team quickly went by the boards in my mind anyway. Q what were your concerns about Mr. Cooper partici- pating with the team? A Well, it became clear that the FBI felt very uncomfortable with his role, ilil^^* ^A^A'^J^M^fihVi'^^ ^^'^Y uncomfortable with our rol There was seemingly suspicion across the board. Anyone other than — at best — career people — you know, who- could-they-trust type of atmosphere. And it was very roromra"" 179 «NCUS«0 difficult to learn what the bureau was finding, doing. And it was clear right from the first, in my mind, that the bureau was very reluctant to work in a constructive fashion with the team that was being proposed. I don't think they had any problem with the Criminal Division personnel, but the whole role of Mr. Cooper and what it implied to them gave them, I suspect, a lot of pause. Now, how high up that pause went, I don't know. MR. McGOUGH: That was as far as I was goin., to go with the background sort of thing. Pam, why don't you finish it up? MS. NAUGHTON: Yeah, I had just really a few questions on this. EXAMINATION BY COUNSEL FOR THE HOUSE SELECT COMMITTEE BY MS. NAUGHTON: Q I gather — on the weekend between the 21st and the 24th, were you in Washington that weekend? A The 24th of November? Q November of '86 — yes. A I believe so. Q Had the attorney general asked you to take part in the fact-finding inquiry that weekend, would you have done sol A Oh, sure. Q And had he asked you to instruct the people who .ry tnac weexena, wouia yi UNCLASSIHED 180 WUSSIflEO work under you to do so, would you have so instructed them to do so? A Certainly. Q If I can go back one minute to what we were talking about in the Evans case- Prior to November of '86 when the whole issue of this certification to the court came up, did the attorney general certify at any other court or was there other discussion on any--on the Evans case or any other case -that the attorney general should make such a certification? A No, I don't believe so. There was the West Coast case, where we had to make some departmental representations to the court, but nothing of that nature. I don't recall right off hand what those were, but they didn't pose, at least to my knowledge, any-- Q To your knowledge, he was not personally involved. A He was aware of it, or so I was led to believe by Bill Weld, who took this up in his early-morning staff meeting. Q My question is specifically in a much earlier time frame--let's say the summer of '86. Was there such an issue raised? A I don't recall any--in the summer of '86? I am not aware of any. Let nie--if I can go back just To^clarify something jcall any--in the summer UNCLASSIFIED 181 iiNcussro that I said earlier that may be confusing. It was in connection with the Evans case. At some point Mr. Weld may have been urging that the inquiry required — not required, but that should be conducted for the Evans certification — be done by the Criminal Division. That I don't know. If that's what he was urging on the attorney general, which may be possible, that may* explain some of the ambiguity that has arisen with respect to my knowledge of what he is telling the attorney general. That would make some--that is a possibility. But I don't recall that being articulated — that we should take over the investigation of both sides of the equation. It certainly wasn't something I was advocating. I don't know if that clarifies it or further confuses it. Q Just for the record, the staff — senior management group meeting that occurs at 8:30 every morning with the attorney general — you are not part of that, is that correct? A No. Q So you were not present when Mr. Weld made those comments . A That's correct. Q I want to skip ahead for a minute to December 1st of '86, and this is right Jj^^tjrg _the _^e^isipn_to_ seek an independent counsellor. I took a note of our last interview with you, and 182 amssm now I can't remember what it means. It's referring to something that Jameson said, who is of course with the counsel for CIA, regarding that the 1985 shipments didn't occur. And this conversation apparently took place in Deputy Attorney General Burns' conference room. A There was one meeting on the — if I could just refer to my notes for a moment — on December 1st. After a lot of discussion, we are urging — we meaning Jack Keeney, myself--we urging Bill Weld to recommend the appointment of special counsel . Now, I think we were favoring at this point a model that had been previously used by the department pre- independent counsel. What we were referring to as a e ur rsnt model is the appointment under existing authority of an independent counsel appointed outside of the independent counsel's statute. Because there was serious question in our mind at this stage, certainly, whether the Independent Counsel Act was being triggered by the facts then known. MR. McGOUGH: Because of the covered person? MR. RICHARD: The — person aspect, the confused facts — I mean, a variety of questions arose as to the applicability of the Independent Counsel statute to the • ••- UNCLASSIFIED And I don't propose to be an expert on the nuances of that act or the prior department positions being taken 183 UNCUSSIFIED with respect to the act, but I certainly felt that it was appropriate to go for an independent counsel model and that if there was any question as to the availability statutorily of the Independent Counsel Act, that we still had authority, independent of that act, to appoint a special counsel. And we were urging that on Bill Weld. There was a meeting on the first with the attorney general — Burns, Bill Weld, with Cooper, Cribbs, Richardson, I think Bill Hendricks of the Criminal Division, Allen Carver — at which we expressed our views to that effect to the attorney general. From that meeting — and the attorney general listened and asked some questions and took it under advise- ment. From that meeting, we then proceeded down to the deputy's office, where we met with some FBI agents, who were there to brief us on the status of the inquiry on the first. It was clear certainly there that the FBI had great reluctance to reveal -- MS. NAUGHTON: Had what? MR. RICHARD: --had great reluctance to reveal all of the information that they were gathering. At least that was the tenor of the meeting, if you will. Now, in answer to your question: if it's all from my notes of that meeting, I can only say that that's something that they probably didn't mention ly say that t Mm 184 _ 1 2l 3 4 5 6 7 « WNCUSJIflEO I don't have the notes before me, but I don't believe Mr. Jameson was at that meeting. BY MS. NAUGHTON: Q If it came from the FBI, then, during an interview with Jameson-- A I don't believe that Jameson-- Q Now, for the record again, your notes indicate that on that date when the issue of Mr. Reynolds' meeting with Tom Green came up, you and others were very much opposed to that. A Yes. Q Could you tell us why? A Well, at this point in time, as I recall, the matter was now with the Criminal Division, and we really saw no justification for someone of that rank and position to be present at what could be an extremely critical meeting with an attorney for a major figure involved in the matter. Q Were you actually present when Mr. Reynolds gave his reasoning for a meeting with — A I believe that occurred in a telephone conversation. Q Were you present for the other half of that conversation? resent for the otner nait UNCLASSIFIED A Yes. I know we discussed it with Bill Weld and strongly urged'Ho oppose Reynolds meeting at all. And we may have opposed even the meeting. I don't recall that. But we certainly, I think, were unanimous in our opposition to Mr. 185 50' C Su«t N E Wuhmiion. O C 20002 Mmsim Reynolds being present. Q Were you present when — did Mr. Weld call Reynolds? A I believe so. Q And were you present? A I think so, yes. Q And after Mr. Weld was through with the conversa- tion, did he explain to you what Mr. Reynolds' reason was? A My understanding is that our arguments that he was going to be putting himself into a position of being a potential witness--that 's already done, so that is not a particularly persuasive argument. I think the agreement reached was that our attorney would be present, which was a significant factor for us that meetings with defense counsel would not be held absent the presence of a Criminal Division attorney. Q I know what I had a question about . The subsequent application to freeze the accounts made through Switzerland — were you — did you take part in that' A Yes. Q Where did you get the account numbers that were used? A Which applications are you_ referring_to? I mean, to initially freeze the accounts? Q These would have been filed. They're part of the attorney general's exhibits — something like exhibit 60 or so. ■ou referring to? I mean, UNCLASSIFIED 186 _ 1 2 ■3 4 5 6 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 a CO.. INC. 25 UNCLASSIFIED A In answer to your question-- Q This would have been in mid-December or so. A Well, we started our efforts to freeze the account fairly quickly. I think it was early December. Judge Sofaer and I had a conversation, in which I think he suggested or questioned what are we doing. It was agreed we've got to move to ensure that there i« no transfers of monies. And we agreed upon an approach to accomplish that as quickly as possible. Now, at that time — at the initial stage where we approached the Swiss — I believe we were given an account number by Mr. Cooper. They had acquired an account number during their efforts, I'm tempted to say, that was given to the FBI either through Mr. Cooper or through the State Department . Q Well, no — this kind of point — did you personally get it from the FBI? Let me start from scratch. Did you author the document — the actual document-- the application? A Well, I worked on it with people from our Office of International Affairs. We stayed, I think, well into the night, if I recall correctly, on some of the applications. The FBI, myself, and the head of--one of our team leaders was most familiar with the Swiss procedures --eft**y y requirements . UNCLASSIHED 187 iimsim 187 Now, where did we get the number? Depending on which request you're addressing your question to, I would say the FBI except for the first request. And the first request — I think the State Department provided it. I apologize — only because it was of no great moment to me other than that we had the account. Q Forgive my ignorance, but what's the reason for the second request? A Well, there were initial steps, if you will, that were taken that were designed to accomplish the immediate objective, which was to freeze the assets. That was the immediate objective — to make sure that nobody was taking money out of relevant accounts. Judge Sofaer and I had discussed the best way to approach this. And we had agreed that we would do it on a multiple-track approach, going to the Swiss government on a diplomatic route, to the ambassador in Washington, and then following it up with a request in anticipation of a formal treaty request. We went this way thinking it was the quickest way to accomplish our objective, and in my judgment it proved to be that way, because we aat. it^ imnLecUaieJ.i__fiOien but not under the treaty. Now, this is an area that is difficult for me to go nto because under the treaty, the responses coming back from m 188 _ 1 2 3 4 5 6 7 8 9 10 11 12 14 15 16 17 18 19 20 21 22 23 24 a CO.. wc. 25 WUSSIf/EO the Swiss to us I'm not allowed to divulge to-- Q Let me ask some specific questions, and you tell me if you can answer them then. The request I particularly want to concentrate on right now describes the--I guess the basis for freezing the accounts as the possibility that it might be U.S. money. A That's correct. Q So is that your first request that you just described--in other words, the basis for freezing the accounts? A The first request was based on a possible 1343 violation of Title XVIII, which was--if I'm not mistaken. The next request included 1^41 and 641. Q So the first one doesn't necessarily contemplate U.S. monies, because it could be a fraud on anybody. A That's correct. Q But the second one did contemplate U.S. monies, b«CAuse it was 641. A The initial formulation of what to ask for, as I recall, was my judgment based on what the FBI was telling me they knew of from a factual point of view. We had to predicate the request on known facti Q Did you--other than the very first account number that was presented in the first request, did you either add account numbers or change account numbers in the subsequent )f view. We had to UNCLASSIFIED 189 jlbl89 _ 1 2 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 I CO.. MC. UNCLASSIFIED M7 C Sunt. N E 25 requests? A We added account numbers, but the FBI was at this point coming up with the data--they were giving Os a«r9to what they found as far as the accounts . We wanted to take the action against any and all accounts, so as soon as we learned of accounts, we would just constantly be sending in our requests . I was getting the data from the FBI . That was my source of information. Q Did you ever get any information from either the Swiss or any other source that any of the account numbers were incorrect? Is that revealing too much? A It is, under the treaty. I'm really-- Q That's fine. MR. McGOUGH: While she's looking, let me just ask you what I hope is going to be one quick question. EXAMINATION BY COUNSEL FOR THE SENATE SELECT COMMITTEE BY MR. McGOUGH: Q Did you have any contact with a prosecution or an investigation out of the Eastern District o^ Pennsylvania into the machinations of an alleged Saudi prfnce by the name--used a lot of different aliases, but the most common one was Al-Masoudi— Al-Masou(i^ ||N| I uWirlrn 190 ^/ liNcussm A I don't recall, but periodically we would get inquiries from the State Department about prosecutions of various reported princes. And they're asking for status. I don't recall this one. Q Do you recall having any contact with Oliver North or anyone at the NSC about such a person? A No. Q How about any — does the name Richard Miller or International Business Communications mean anything to you in that context? A International Business Communications? Q IBC. A No. MR. GENZMAN: Also the name Zadeh--Z-A-D-E-H, which I believe was the name- he was prosecuted under. MR. McGOUGH: Ho was prosecuted under Zadeh in the United States Eastern District. MR. RICHARD: And the charge? MR. McGOUGHl Attempt to defraud the William Penn Bank. MR. RICHARD: William Penn Bank. Go njid e iabl - y ', only because it iS not unusual for me to get these calls about would-be princes and connections with various royal families and what have you. But it just doesn't ring a bell. lll\lfi!il.winFn 191 ' C Sam. N E 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 "25 \!mmm What I normally do is just inquire on the status and pass that on to the State Department. MS. NAUGHTON: I do have one other question, I think. EXAMINATION BY COUNSEL FOR THE HOUSE SELECT COMMITTEE BY MS- NAUGHTON: Q I'm referring you to your notes of December 1, '86. And towards the bottom here it says — when it's talking about Secretary Weinberger — A At the bottom? Q Where it says--it refers that Secretary Weinberger said that the '85 shipments didn't occur. Do you know who was talking or what they're talking about in that note? A This is part — as I interpret my own notes — this is part of the December 1, '86 FBI briefing which occurred in the deputy's conference room. And this is the FBI conveying thl8 information. I see earlier, incidentally, that they make reference to George Jameson, so that confirms the suspicif^ns that it was-- Q Do you recall the FBI telling you that Secretary Weinberger had said that 1985 shipments did not occur? A I can only refer to the notes — the fact that they here suggest that the representation was made, but the FBI-- that this is what is emerging. Now, where they got it from, 192 jlbl92 BNCUSSm I don't know. MS. NAUGHTON: I have no more questions. Thank you. MR. McGOUGH: I have nothing further to make. Bob? MR. GENZMAN: All the points that I had have been covered. I thank you for your time, sir. [Whereupon, at 6:12 p.m., the taking of the deposition concluded.] UNCUSSIFIED 193 ONCIASSIFIEO CERTIFICATE OF NOTARY PUBLIC I, William D. McAllister, the officer before whom the foregoing deposition was taken do hereby certify that the witness whose testimony appears in the foregoing deposition was duly sworn by me; that I am neither counsel for, related to, nor employed by any of the parties to the action in which this deposition was taken; and further that I am not a relative or employee of any attorney or counsel employed by the parties hereto, nor financially or otherwise interested in the outcome of the action. William D. McAllister Notary Public in and for the District of Columbia My commission expires October 15, 1989. mmzm 194 Memorandum UNCLASSIFSEO J 3 ^/-'^£l J 4782 Boland Amendment April 13, 1984 Mark Richard Deputy Assistant Attorney General Criminal Division •Victoria Toensing Deputy Assistant Attorney General Criminal Division Stephen S. Trott Assistant Attorney General Criminal Division Please contact Mary Lawton ASAP and prepare a memo on the Boland Amendment. What it is, why it was passed, what it was intended to accomplish, and when and why it expired (Sept. 83 ?) etc. What is the effect of its expiration on our problem? Richard Willard and Ralph Tarr insist that § 1341 means that if zero funds were authorized for "mining activity" etc., the expenditure of$1 violates the Antidef iciency Act. It is
a technical argument at best, with respect to a statute that
has never been enforced — or even thought of in this light.
Any thoughts?
Stay in touch with Lowell on this during my absence.
I^Declassilied/Released onJ^it«So
under provisions oi E 0- t23i5
K Jonnson. National Setunry Council
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STEPHEN S. -mOTT
ASSISTA^f^ ATTORNEY GENSWL
Room ^4o.— 8ldg.
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197
l!NCUSS!FIEO
The Deputy Attorney General
March 20, 1966
Oliver B. Revell
Executive Assistant Director
Investigations
INFORMATION MEMORANDUM
The entire contents of this memorandum are classified
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We have reviewed the attached draft ""-
teletype and proposed letter from "v" -^-^
Assistant Secretary Abrams, and discussed
this matter with Roger Yochelson of OIA. ■ -.
We note two inaccuracies in A/S Abrams' ■-■
letter. First, contrary to the assertion
[ustice has not intervened
oehalf to recommend that -rs)
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the Government wasrf>0(>-.
Since then, we V" '^
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A/S Abrams represents that Justi
prepared to brief the |
on the evidence and legal process
case, we are not aware of any such plans
We understand that the attached
communications have not yet been sent.
We strongly urge that, before transmitta
A/S Abrams' letter and the draft teletyp
be modified to clear up these two points
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Southern Olitrlct of New York
SENDER'S FTS PHONE NUMBEF
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MtMHlLJ HAJHINI
VERIFICATION NUMBER
662-1139
SPECIAL INSTRUCTIONS:
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THIS SHEET MUST BE USED OH AIL TRANS-,SS,ONS THAT ORIGINATE FROM 5.O.N.Y. U.S. AHORNEY'S 0.
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UNCLflSSIfJED
J 4006
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This statement is aubmltted'ln response to the Court's
inquiry concerning the e«e=t on this case of recent .laclosures
concernln, th. authorized shipment by the United states of ar.s
to Iran. At the Courf. re.ue.t we address three issues: :, the
-rits Of the case. 2, bail, and 3, the scheduled trial date
MERITS OF THE rxtv
All Of the charges in this case arise out of the
defendants- schemes to .a., false statement, to the United •
States. The events discussed by the President late last weeK
have no bearing whatsoever on the illegality of plots to defraud
.the United States, as charged in Indictment ssss 8« Cr 38.
(LBS) .
The indictment charges three type, of crimes all
arising fro. the defendants- efforts to misrepresent to the
united states the intended destination of ar.s, which the
defendants in fact were attempting to sell to Iran. The first
five count, charge conspiracy to defraud the United States and
n.a.e false statements. The next .6 counts charge a scheme to
defraud the United States using wire and mail conununications
The last five count, charge that .ome of the defendants actually
-de false statement, to the Office of Munitions Control in the
Department of State.
The Department of Justice'i^^^l^;;^^,^ this case in
connection with the recent event. ^ di.cussed by Present .eagan
"U«".t^iS:!^^ ^''^^"^"^ >^^"3S last Thursday. The Department
havdvi^TJ^Cnited states Attorney, office that the.e events
taMb Oeciassiliedmeteasea oniZ_i_5^23
u„toBto.«onso.tO .2356
by K Jolinson. Nalional Zewu-.f Coiiiicil
209
mussmEo
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charged in the Indlcwent. The United States Attornc^^Of f Ice
exist by virtue of those «^^""- ^^=5^^^^^°^
previous statement/that A:here is nct^t^i^ p^^H^
def/ndits/were a/part /f any /of ficiiuJsa/ctioLd e4foAs by
the* United State/ to ship ary(aments/to fr»n-J
we would respectfully remind the Court that five
eeparate conspiracies or proposed arms deals are charged in the
Indictment. In connection with only one, the "vlanar
conspiracy,- did any of the defendants discuss or even suggest
during the undercover negotiations that the specific arms deal in
question had teen submitted to the United States r.overmrent for
approval and that the Government was considering it. As for that
propocal, that aeeertion that the propcial was ,.r>^Hnn»,l i»
demonstrably inaccurate and, in any event, unrelated to the
recent disclosures. I As for the remaining four conspiracies, the
defendants' assertions that the transactions were authorized are
also without foundation. They are speculative defense raised by
counsel only after the arrests. 1
Accordingly, the Government submits that the merits of
the case are not affected by recent disclosures and news reports.
All of the defendants are free on ball except the
defendant Albert riearmoy. We have agreed to a bail package for
Mr. riearmoy in view of his representation last week for the
..... .._„ •h.t he actually ha- 'n^-^. to deposit as security for
UHCLftSS\?:£0
210
ijHcimim , ,„„3
hi» release. Until last weak, Plearmov's counsel had not
pi«b«iiL«a rot Llie courl,'6 consiileiaLlon any bail conditions that
rlearmoy could meet.
We oppose any modification to the bail conditions
previously set by the Court for the remaining defendants. In our
view, the trial should proceed expeditiously as scheduled, and
the strength of the Government's evidence is unaffected by recent
disclosures.
TRIAL DATE
All pretrial proceedings should be concluded in a
timely fashion such that trial can begin as scheduled on February
2, 1987. In view of what Is described above, there if no basis
for additional discovery related to the recent disclosures.
Moreover, defendants cannot raise an apparent authority defense
Accordingly, as discussed in the Government's memorandum of law
in opposition to the defendants' discovery requests, defendants
are not entitled to information related to the recent
disclosures.
fr»
*V
lMCLASSiF:t3
211
iummi
DEPOSITION OF JOHN N. RICHARDSON, JR
Wednesday, July 22, 1987
U.S. House of Representatives
Select Committee to Investigate
Covert Arms Transactions in Iran
V3^^
Washington, D.C.
The committee met, pursuant to call, at 1:30 p.m., in
room B-352, Raybum House Office Building, with Pamela
Naughton (Staff Counsel, House Select Committee) presiding.
Present: Piunela Naughton, Staff Counsel, Staff Counsel,
House Select Committee; W. Thomas McGough, Jr., Associate
Counsel, Senate Select Committee; emd Kenneth Buck, Assistant
Minority Counsel, Rouse Select Committee.
Also Present: Jack E. Perkins, Deputy Assistant
Attorney General, Office of Legislative Affairs, U.S.
Department of Justice. ^ _ , r.^/ooiBased on LZ^ —
212
UN(IH$»PT 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 p^ " »«•««» 19 CO 20 — . 21 S»^ 22 * " ^ 23 MS. NAUGHTON: Could you state your full name? THE WITNESS: John North Richardson, Jr. MS. NAUGHTON: My name is Pam Naughton. I am Staff Counsel to the House Select Committee to Investigate Covert Arms Transactions with Iran. MR. McGOUGH: Tom McGough, Associate Counsel to the Senate Select Committee. MR. BUCK: Kenneth Buck, Assisant Minority Counsel, with the House Select Committee. MR. PERKINS: Jack Perkins, Office of Legislative Affairs, Department of Justice. BY MS. NAUGHTON: Mr. Richardson, could you tell us what your title Q is? A Of staff. Q A It is Assistant to the Attorney General and Chief What do your duties include? I am basically responsible for the office operations. Office of the Attorney General, and that includes supervising a number of lawyers, the paper flow in and out of the office, the schedule operations, travel operations, and basically daily management of issues that are coming through the office. Just so I have the structure correct, at around October-November of '86, Mr. Cribb was in your office. 213 Kenneth Cribb? A Right. 3 Did you work for him or was that sort of separate? ^ A Yes, I did. He was Counselor to the Attorney 5 General and my reporting relationship was through Cribb to 6 Meese, although as a practical matter, I did a substantial 7 amount of my work without checking with him. 8 Q Now, could you tell us where you graduated from law 9 school? 10 A University of Virginia. 11 Q What year was that? 12 A -82. 13 Q What did you do after law school? 14 A I was Law Clerk to a U.S. District Judge in 15 Richmond, Virginia for one year. 16 Q Which judge was that? 17 A Dorsch Wariner. 18 Q Okay, and after that one year Clerkship with the 19 judge, what did you do? 20 A I joined the staff of the Counselor to the 21 President, Mr. Meese, when he was at the White House. 22 Q This was in '83? 23 A Yes, June of '83. 24 Q What did you do as Mr. Meese' s assistant at the 25 White House? UNCLASSIFIEO 214 IRffiBSaBST 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 So 21 »^ 22 ■t* ■% 23 ^^ 24 25 A I was a volunteer in that office for the first couple of months, and I basically worked as assistant to Ken Cribb, who was Meese's assistant. In August, I was put on the payroll and for the first probably six months, I worked primarily on judi^5c.al selection matters, and preparing briefs for meetings and reviewing incoming papers, helping to organize them, and whatever projects Cribb gave me, Q After that period of time? A Then Meese's Special Assistant left the staff. I was made Special Assistant and I guess my duties, the responsibilities, increased. I became involved in more substantivie matters, more meetings. I would attend meetings and occasionally with Mr. Meese, take notes. Essentially the same, but I guess doing more of that. I became, when he was nominated to be Attorney General, I was working on the confirmation document production, working on those issues. I guess I also was, I was the lawyer — Cribb and I were two lawyers on the staff, and when, for example, when debate came along, I was tasked with going through all of his documents to see if anything was responsive. So I would take on projects like that, too. Q During your years at the White House did you do any staff work regarding Mr. Meese's role in the National Security Counsel or NSPG? A No. I saw paperwork occasionally but no staffing. 215 9 10 11 12 13 14 15 16 17 18 19 20 21 22 i ZSZ 23 -**-' 24 llMl^l^iiG as I recall. Q Did you attend any meetings either on your own or with Mr. Meese during that period of time at the White House regarding funding for the contras, Nicaraguan resistance? A 1 don't think so. Q Did you participate in any discussions or any meetings involving soliciting money from third countries to support the contra movement? A No. Q Did you have anything to do while you were at the White House with processing any form of findings for covert actions? A No. Again, I may have seen certain documents in the safe if I were looking for something like that, but I was not otherwise involved. Q Do you know what your clearance was while at the White House? A I think top secret, but — Code word? A No. I think I would know and I don't, never knew about code word until I got to the department. Q When did you get code word clearance? A Well, it was definitely after March of eighty -- let me think here — I came to the department in March of IOC Tfc ....e er^m« *■ i mo mfi-fr that. I don ' t know precisely. 216 IWKI^RP^T CO Q Shortly after? A After I had been at the department several months over doing^^^^^HH^H^Band for a when I took that task on, ?ti»fei Gailback in the office continued to do the code word stuff that would come in^^H ^^^H I took those over — I am not just sure when it was. It was a substantial period of time. 24 217 #\J ts»# ?A^^ 7 a!»*« 218 mmm CO 00 21 Now, along this same period of time, in '85, early '86, were you aware of efforts on the part of DEA agents to be tasked with locating and/or extricating hostages held in Lebanon? A No. Q When did that come to your attention? A I am not sure. I know it was some substantial period of time after the Iranian initiative had been made public and — Something after November of ' 86? A Definitely after that, and it may ~ it could have been later than that. 1 think I became aware of it when it became a matter of general public discussion. that there had been some sort of DEA assistance. Did you have any discussions with the Attorney 219 Wtt^SlifiilT 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Cfc^ 20 C<>21 ^SC 22 c«^ 23 :-— ^ 24 A After I learned about it? Q Yes. A I don't think so. I know he was briefed by Jack La^n, but I did sit in on that briefing, other than to say something, I may have said we need to find out what DEA did, or something along those lines. He didn't have any detailed discussion of it at that point. Q Do you know of any discussions with the Attorney General in which you either participated or were present at which the subject was mentioned that private funds were being used for this operation? A Well, more recently, the last couple of months, there have been discussions like that, saying where we have learned some information about what DEA did and who was involved, but back at that point, no. I guess that is your question, back when we first, when I first learned about it? Q What I an getting at is, was it ever discussed at any time between the Attorney General and anyone else in your presence, including yourself, that private monies had been used for this operation? In other words, had been authorized to be used or there was a discussion to the propriety or legality of it? A There have been, there have been discussions about 220 1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 *^*^ 19 g- ^ 22 S^ 23 24 UVEU^IclffiiT that in the last two weeks, for example, but not before that I recall. What were the discussions in the last two weeks, do you recall? A Well, it was basically going over matters that have been of public interest, preparing for his testimony, and I asked from DEA General Counsel last week, the Chief Coxinsel, documents that had been provided to the Hill so I could inform Meese and inform the Attorney General about what might be reviewed. So it was in that context. Q Did the Attorney General tell you whether or not he authorized the use of private monies for the DEA operations A He did not tell ine that he authorized it. Q Did he say he did not? A I don't think he was aware of it. That is obviously something that you should ask him, because — Sure. A There is no discussion of — that I recall -- of his having authorized it. Q I want to take you to a tine around March of 1986. There is a case out of the Southern District of Florida, in Miami, that is known by him at this time also. One is Garcia, one is Corvo, and it has to do with basically two things, an alleged assassination plot against Ambassador Tambs , and o^-.«. «1 1«»r,.HfM^e nf nun rnnnino to the COntraS . The 221 uiieu»EfeT investigation began sometime on or about December of '85, and continued through '86. Do you recall when this case first ciune to your attention? A No, I don't. Q In March of '86, or thereabouts, do you know whether or not you were aware of the case? A I don't recall being aware of it. It is only recently that I have been -- it is something that is recognizable. Q So, you don't think you learned of it until, shall we say, after November of '86? A Well, the question dealt with March of '86, right? Q I am trying to get a handle on when you first learned about the case. A Okay. I think it is clearly after — I believe it would be after November of '86. It may have been much more recently, since the beginning of the congressional hearings on this initiative. Q Are you aware, or were you aware, or are you now aware, of any requests by anyone on the staff of the National Security Counsel for a briefing on this criminal investigation? A I was not aware of any requests at the time that thev were made. 222 itOiftSglKST 00 19 Q Have you since come to learn NSC requested such a briefing? A I an not sure. I believe — I am not sure if they did or not. There have been a number of subjects that have been covered in prep sessions in the last week or two with the Attorney General, so I am not familiar with the details of it. I may have heard something along that dealt with this subject, but I don't recall it, so I am really not in a position to answer. Q Moving along to the month of November '86. Were you aware on. or about November 7 that Chuck Cooper was being tsked to look into the legal raunifi cations of the Iranian arms transaction? A K believe I found out the tasking to Cooper fairly son after it was done, and I think I found out from Cooper, but I eun not positive. But I did know fairly soon after that Cooper had been tasked to look into some of these issues. I think it came up in the context of asking the AG about making sure that we, OLC, is looking at some of these question and the AG having said Chuck is working on that. Something like that. Q Was there any discussion at that point -- let's say from November 7th until the 20th — regarding whether or not the Criminal Division should taOce a look at it, being as though the Arms Export Control Act and other Acts may be wmmk applicable? A I don't recall any discussions suggesting that, but 1 wasn't — I was not intimately involved in that during that time period before the 20th. Q Did the attorney — A OLC would normally advise on matters like that, as opposed to the Criminal Division. Q I am not asking about advise, I am asking about investigation. A No, I don't think there was any discussion. I certainly was not aware of any, present in emy discussions where it was suggested Criminal Division investigate anything 6 Did the Attorney General tell you whether or not he had asked Mr. Cooper to do this of his own volition, or whether or not he had been asked to help with a legal analysis by anyone at the White House or NSC? A I don't know the answer to that. He didn't explain the reason for doing that. You don't know how it was initiated? A Other than the Attorney General asking Cooper to do it, no. Q Mr. Cooper has testified that he prepared a book of statutes for the Attorney General to review. Did you see that book or — 224 Did it come through you or -- A I don't think so. 1 think he handed it to the Attorney General. And how is it that you came to look at it? A I specifically recall seeing it over the course of the couple of days before and during the weekend. Well, I say I know during the weekend fact finding inquiry, I am not sure about the days before. But I know I saw it over the course of that weekend and afterwards. Was there any analysis in the notebook or was it something of compilation of statutes? A I am just not sure. I think it was a combination of statutes, but he had done, as I recall. Cooper had provided a legal memorandum by the time of the weekend inquiry and so whether that was in there, I don't remember. I tend to think it was just the statutes, though. Meese is very committed to looking at the law. He doesn't like for you to tell him what it says, he likes to look at the statute and all that sort of thing. Were you aware whether or not the Attorney General participated in drafting or reviewing any of the President's statements that were made between the time period of say, November 4th and November 2 0th? A Can you give me a hint about what they would be? n Won f-h* President aave a statement, I believe. 225 SKttHSSiFKS'^ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 i^UJ 17 i±: 18 23 24 Yes. I just don't recall whether he did or not. Do you recall getting any drafts from the White on November 13th. A That was that speech to the nation? Q Yes. He had another press conference on November 19th. A House? A I just don't remember. I know, I don't think we got anything circulated formally. That is, through the Office of Cabinet Affairs at the White House into our Executive Secretariat. Q If it got circulated informally, would it have come through you? A Most likely it would have come through me, because there are standing instructions on our staff, which Meese's personal secretary abides by as well, if a package comes in it is normally kicked to me. So I probably would have seen it, but I just don't recall whether one was sent or not. He have done, as I said, we have done a couple of speeches on a close hold basis where a text would be sent over and come to n^ and he would take a look at it, but actually statements were more on the point, but I just recall it if these were one of them, I tend to think not, but I am just not sure. I know after the 25th of November, for example, 226 yHJHraWFr OO 20 the President's statement on the 25th of November, Meese was involved with, and I don't know, I know there was a statement concerning -- I believe it concerned immunity in December of '86, that I think he was involved with, but I recall those, but I don't recall the others. Q Moving then to November 20th, the Attorney General was scheduled to spend most of the day at West Point. Do you recall what it was that cancelled or changed those plans? A It was basically I think twofold, but his reaction to the President's news conference and the next — that was a Wednesday night. The next day, Thursday, I believe there was a meeting scheduled in Poindexter's office to review Casey's testimony, and either Poindexter's testimony or material he was going to use to brief members of Congress. I think, I don't know if the AG called me Wednesday night or if I found out first thing Thursday morning, but he called and said that he was going to be attending this meeting and that he would delay his departure by I think it was four or five hours. I believe he was scheduled to be in classes at West Point teaching, and that sort of thing, Thursday afternoon. He delayed it until a dinner function. Q You made those arrangements? A Well, I probably called our travel guy and said fi-^ t-K-ie Ko^xiea >%o -i o r.n«- oninn tn 1 pava iin<-il " X" time. 227 w&im^ but I think the Army, I believe flew him up there, so it was pretty simple. They were providing the plane. So I think we delayed his departure time. Q Does the Attorney General have a driver? A Yes. Q For all his transportation? That is from home to office and meetings and so forth? A Yes. If he goes out, he will frequently not use a driver on the weekends, or unless he is going to a particula function or something like that, but if he leaves the house he normally has an FBI person with him and sometimes they will go in his car, sometimes the FBI car, but for business functions, he would be brought to work by the department driver and taken to and fro. Q When would it be he would have an FBI driver with him? A It may be on weekends. If say it is Christmas time, if they are going to go out to get the tree on the weekend or when he goes to chrjuoion Sunday, I think they drive a family car and the FBI follows him to church. So it sometimes, like in those circumstances, they would not, he would not have an official driver. Most of the time, he does. Q During the weekend of November 21 through the 2 3rd, do you recall whether or not for that period of time, you 228 CO mmm ' vehicle? 2 A I think he had, well I used the personal vehicle. 3 For example, when I went over to the White House to go through ^ Ollie North's documents, but I believe the AG had his driver 5 on duty that weekend. I recall after lunch on Saturday, his 6 getting into his department car and I could be wrong on that, 7 but that is my recollection. 8 Q Now, we were on the 20th and the delayed departure. 9 Do you recall, did you see a draft of Mr. Casey's testimony 10 prior to the meeting to review the testimony on the afternoon 11 of the 20th? 12 A I don't think so. I don't recall it if I did, but 13 I don't believe I did. . 14 Q Did you see it after that? 15 A I don't think so. I mean, I may have seen a 16 document, I may have seen a draft in Chuck Cooper's hand, for 17 example, but I don't recall having looked at a draft. 18 Q Were you at the session to review Mr. Casey's 19 testimony? 20 A No. 21 Q Did you speak to the Attorney General about it 22 after he returned from the drafting session? 23 A No. As I recall, he went straight from the White 24 House to I think Andrews Air Force Base and on up to West 9R Point. 229 mtifsm COao Q Do you recall when that was? A Well, I made an inquiry to try to find out, and this is more recently, and I think it was, I believe he had wheels up at around 4:30 and/or 4:40, and so it is probably — I think we estimated he left the White House around 3:30, because at that time of day, it is probably 45 or 50 minute drive out there. I think their takeoff had been delayed by rain or something. It is in the 3:30 range. Q Now, do you recall the Attorney General receiving any calls from anybody at the Department of State on the afternoon of the 20th? A No. I just don't recall. Q Do you know whether or not he spoke to Judge Sofaer Legal Advisor from the State Department? A I don ■ t know . Q Do you know whether or not he spoke to Secretary of State Shultz that day -- the 20th? A I don't know. Q Would those calls normally have come to you in his absence? A I think if the system worked, I would have been notified that they had called, but I just don't know whether I was or not. If he was not in the office a call like that would be put on his telephone log and frequently if a Cabinet official calls, I would return it and see if there were 230 uveuHb 20 C/O anything that we could lend a hand on, although I don't recall whether there was a call or whether I did that. Do you know whether or not Deputy Attorney General Burns received emy telephone calls from the Department of State that day? A I have been told since that day that he did. I didn't know that he had then. Q When did you learn that he had? A I recall learning about it in the last several weeks. Q So it was not brought to your attention at the time it occurred on November 20th? A That is right. I don't recall it having been. Q Did you speak to Mr, Burns eibout it after learning about. it? A No. Q How is it that you learned then that that telephone call took place? A It may have been during congressional testimony, which I was watching on TV, or it may have been from Chuck Cooper. Were you present when Deputy Attorney Burns spoke to the Attorney General about this phone call? A up, I think we figured out that Meese probably took the call No. I mean, I think a fewll^eks ago when this came 231 mtmim C^1~. oo 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Q When you say we figured out, who is we? A I asked a couple of my secretaries in the office to figure out when Meese took off from Andrews, talked to Cooper to see how long the meetings was in the White House, and I guess Chuck Cooper indicated the approximate time of the call or that information came from someone, and the estimate was Meese was probably in the car when it happened. Q So the Attorney General did not tell you about the call I guess at any point and certainly not November of "86, is that correct? A I don't recall him mentioning it in November of •86. He has mentioned it in the last several weeks. Q Now, on the evening of the 20th, were you called by anybody from the Department of Justice regarding the discrepancies that had come up between the recollection of Secretary Shultz and the statements made in the Casey testimony? A I don't think I was. I don't believe I was. I believe I got a call. It might have been from the Attorney General, or from the staff member who was in West Point with him, indicating that -- probably from the staff member — but indicating th*t he had had a conversation with Chuck Cooper and that he was returning to Washington first thing the next morning and cancelling the Friday leg of his trip, and I believe I called that night, Bruce ZanXa, who is our travel. 232 nmssieiitrr 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 ££ 18 ^- ^*^ 20 ^? 21 S^ 22 23 he handled traveling arrangements for the Attorney General to make sure everything was wired. I think I put him in touch with West Point. Q Do you recall when it was that the Attorney General arrived back in Washington, D.C. on the 21st? A I don't recall. I know in looking back at staff meeting notes that — I don't think he was at the 8:30 meeting that day. So he may have arrived right afterwards, but I think it was fairly early, at the start of most people's day, a couple of hours after he normally begins. Q Were you at the staff meeting on the 21st? A I think so, because I believe I saw some of my notes from that day. Did anything occur at the Friday morning staff meeting that is of relevance to the Iranian arms sales or the Nicaraguan resistance? A Well, there is an entry from my notes where the subject is mentioned but there is nothing significant. I don't think there was anything significant at the time and now I don't think anything significant occurred. MS. NAUGHTON: If you could _Bark this, please. (Exhibit No. 1 was marked for identification.) BY MS. NAUGHTON: Q I am showing you what has been marked as Exhibit No. 1 to this deposition. Are those your notes? 233 'DTIliCRMintO A Yes. Q Of the staff meeting? A Yes. And your notes indicate, do they not -- firstly, do you know where the originals of these notes are? A I believe they are in ray office's possession with material that -- I think what we have done is kepi an original of everything that is produced and they are I believe with that. Although they have been searched in response to other document requests in other matters from the Independent Counsel Walsh and another matter. They have been reviewed for relevant material for another matter, so I can't — I provided to the Independent Counsel Walsh originals of most of my notes, if not all, in this matter, and I don't think I provided the originals of these notebooks to him, I think I still have got them. They are one of two places. Q We were told last Friday at the Department of Justice that the originals were at the White House. A Mo , no . Q To be kept for Wedtech. A Those are Meese's notebooks -only. Q Your originals are then, where precisely would they be? A I can't tell you. I don't know. We have got — we have got — there is a location in our office where we 234 mffiusstPti&T 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 ^:^ 18 \±=1 19 CO 20 c::;s:s. CJ^ have got all of these, all of the original materials. I think they are put in one location to be made available for inspection. What is it? I am not sure if they are physically in the White -- what is in the custody of the White House are Meese's spiral notebooks, handwritten notebooks in spiral notebooks. If we can then go to this exhibit, which is obviously a redacted copy. Thre is an entry that says "Weld" — which 1 assume refers to Assistant Attorney Weld Assistant Attorney General for the Criminal Division, is that correct? A Yes. Q And the reference teads "How long AG to carry legal load alone — various agents involved. JJIB';" whom I assume is Mr. Bolton, he is A^^"^£ant: Attorney General for the Office of Legislative Affairs? A Yes sir. Q 'Response focus Cooper, et cetera — as develops," and then Weld again, "CRM Division,". *ihich I assume stcmds for Criminal Division? A Yes. Q "Needs to be informed for intact on other cases." A Yes. Q Could you tell us exactly what those notes indicate the discussion was? 235 wmssifliiT A Okay, I don't have a specific recollection but this is what 1 think they mean. That Weld was mentioning that the AG should have others involved in trying to figure out what statutes were implicated by the transactions that we knew had occurred. Q You are speaking about the U.S. sponsored Iranian initiative arms transactions? A Well, I am speaking of the Iranian initiatives and I guess at that point, we didn't really know. I am not sure when precisely I became aware enough to know there were questions about what happened in '85 and who had sponsored or approved, but it is that whole series of arms shipments and initiatives in that regard. Bolton pointed out that Cooper is already involved in that, that his office has been the focus of this legal review and Meese was not, that the department was formally involved in doing that, Meese wasn't doing that alone. And that then Bill's point. Weld's "point for second .entry is that Criminal Division needs to be informed of for^ impact on other cases. There were, as I recall, there are pending arms shipment cases in a number of districts around the country and he was just concerned that whatever legal conclusions or factual development, I guess I think the legal conclusions OLC was reaching were they were aware of. Q When you say Mr. Weld mentioned the AG should have 236 \!SMSS»ET C^ others involved, did he mention the Criminal Division? A No, I don't believe this was — this referred to getting the Criminal Division involved. I think it just referred to generic comment that there are others that need to be involved, the department needs to look at these legal questions. I guess he was not aware that OLC had been tasked to do that, which is what the Bolton note indicates. Q Did he indicate in any way concern with the Attorney General acting as fact finder? A I don't recall anything along those lines, no. I think I would have — I don't have any specific, clear recollection of this meeting, but I think something like that I would have noted in my notes because this was what makes me think the AG was not present because I wrote a note here on the margin, AG, with an arrow and star. That star cir<gled for me is an action notice which hopefully I follow up on. That mefuis to me that I need to tell Heeae about this conversation or this suggestion and I think if there had been a concern raised by the AG that is the kind of thing I specifically would have written down. Q Was there any other discussion other than Mr. Bolton's reply to Mr. Weld's comment? A I don't recall any. Q Since you indicated with a star it should be 237 ORKlWfffiE' followed up, did you follow up on that? A I don't recall doing that or not. Q Did you tell the Attorney General about this comment when he did return on the 21st? A I don't recall whether — I don't have any recollection of doing that or not doing that. Q Did you tell him at any time? A I don't recall. I just have no recollection of such a conversation. I mean, I was not, I may have or I may not have, I just don't recall, but this notation means that this is something I think I should tell Meese about. This is not a tasking to me out of the meeting that I have action on Weld's behavior to inform Meese. That is what I try to do. This kind of notation would not indicate that I have been tasked to take this and be assured that it is done. Q Did anyone inform the Attorney General of Mr. Weld's comments in your presence? A I don't recall. whether they did or not. This reference to things like this New York case, where there is an arms shipment prosecution underway amd -- Q Well, let's get specific when you say this. Are you referring to his last -- HMO! AOOirir'^' imE This last entry. r»-iminai Division needs to be informed? 238 mmm! ?5 " CO 20 ^^ 22 ~-^ 23 24 A For impact on other cases. That refers to the New York case? A Yes, that is what I believe. Q The first reference, however, to the Iranian arms shipments? A Yes. Q I wanted to be clear. Now, when that meeting broke up, do you recall whether or not this subject was discussed with anyone . informally or as the meeting was breaking up? A I don't recall. . Q Do you know whether or-^ot the Criminal Division prepared any research papers or irfeerials or memoranda on the Iranian arms sales, the U.S. initiatives? A Well, I have been told that they did and I saw such a memo this week for the first time. I don't think I knew until the last few weeks that they did. But apparently such a memo was prepared, either over the course of this weekend or this weekend in November of '86. Q Who brought it to your attention that the Criminal Division had prepared a memo? A I don't recall. Q Did Mr. Weld? A I don't think so. It might have been Cooper or e^l 4-nn K.i«- T Hnn • ♦• i-«»f»1 1 . (infliji^asiiT 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 S" rT* 18 CO 19 i«^ 20 So 21 • ^^ 22 23 24 Q Do you know where they received the information that a memo had been prepared? A No. Q Moving along then to when the Attorney General returned the morning of the 21st, when he first returned, did you meet with him? A I don't recall whether I did or not. 1 probably did, but I don't recall whether I did. Q And what can you recall that happened Friday morning; the 21st? A I~J3elieve that he went over to see the President late morning, and I recall that we got together for lunch — Cooper, Reynolds, Meese. I am not sure if Bolton was there, but he may have been, and myself. And he told us how we were, what the President had asked him to do and how we were going to be spending the next couple of days. Q Well, prior to the Attorney General's going to see th« President, were you aware he was going to see the President? A I probably was, yes. Q What did you know prior to that meeting taking place, what did you understand was the purpose of that meeting? A I don't think I knew the purpose. Q Well, you knew the Attorney General had cut short 240 llWCUCCiriHi,, 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 S '' CO 19 ^ ■* 21 ^^ ^ 23 24 his trip. A I surmised things, but I don't think he told me what he was doing. I knew he was going over to the White House. You didn't know why? A No. I assumed it was to discuss the topic of special interest, which was the Iranian initiative. But I don't recall whether I knew what problems there were or not. There may have been a Friday morning meeting that I attended. I just don't have any recollection of it now. There may have been a note or something that would refresh but I don't recall. Q When the Attorney General returned from his meeting with the President, what did he tell you about that meeting? A Well, as best I recall, over the course of lunch, he said that the President had asked him to conduct a fact finding inquiry to try to determine what had transpired in this Iranian initiative, that there seemed to be different recollections of what had happened and that it didn't seem that anyone was in a position or did know the full set of facts, and there was going to be a NSPG meeting on Monday and that the President had asked Meese to try to look into the matter and see if he could put together a factual picture on v^at had occurred. 241 yPifBF 1 2 3 4 5 6 7 8 9 10 11 12 .13 14 15 16 tHuT OO 20 Cii^ Wednesday night he was concerned because I think the statement about not, no third countries being involved, I think he was concerned about the performance of the President and inaccuratu statements being made, and he was concerned that he had not been properly briefed or informed, and I gathered from the lunch there had been a discussion, the meeting the day before had resulted in the viewpoint that their people didn't seem to know what was going on, and that the President didn't have a complete picture of the facts. Q When did he tell you that he was concerned about the President's remarks at the President's press conference? A I don't recall specifically. I don't know that it was -- it was a poor performance in the press conference, there seemed to be — this is my own impression — the President seemed to be unsure about some of the facts, seemed not to understand that question. A correction was issued and Meese, I don't think we got into detail, but I think that as I recall, he shared that impression. Q But do you recall when he shared that inqsression? A No. Q Did the Attorney General indicate to you when he met with the President, in what capacity he was setting forth on this fact finding inquiry? A I just don't recall. I don't recall that. I don't think so. 242 yuiv^^ . itwgissifir i 1 Q I guess my question is did he explain why it was 2 that he, Ed Meese, Attorney General, was going to be tasked 3 with finding the facts as opposed to a Don Regan or Mr. 4 Wallison or Secretary of State Shultz or someone else in the 5 Administration? 6 A I don't think he explained to us where the 7 President wanted this done. I think he told us we were going 8 to do this. It didn't seem odd to me, so I didn't ask about 9 it. 10 Q Did he explain whether or not it was the President 11 that tasked him with this or whether he asked to be able to 12 do it? 13 A He did not state which of those was the case. He 14 just said the President wanted him to do this or had asked 15 him to do this. 16 During that, I guess you met for lunch that day? 17 A Yes sir. 18 Q Do you recall who else was present? 19 A I recall Meese 2uid Reynolds, Cooper, Richardson, 20 I think Bolton may have been present, but I am not sure. I 21 know Bolton was present at a simular lunch the day before. 22 Q On the 20th? 23 A Yes. 24 Q Was part of this discussion at lunch surrounding 25 Mr. Casey's testimony? UNCLASSIFIED 243 Take 2 T. .AS:mhl fls myself 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 9f> HNteASaflBlT lUi-J LA- A Part of the discussion, certainly. It certainly involved that, but we didn't have the testimony. It wasn't a session to go over the testimony as I recall. I think the two — again, I had not made myself intimately familiar with the facts in that sort of thing at this point, but I, as you recall. Cooper was reviewing some of the applicable legal requirements, and Bolton was updating him on events that were underway with the Hill, and I don't think that the testimony was passed around and gone over, but I think it was, certainly it was in the context of Casey going up the next day. I think Bolton might have been at this lunch Friday because at some point he debriefed us on, he sat in on some testimony and took some notes, I think at some point he debriefed tH&ese on what had happened. Q Do you recall when he did that, what his statement was regarding what Casey had told Congress regarding the November 1985 Hawks? A No, I don't recall that. Q Now, as far as the lunch on Friday, can you tell us what was discussed? A Well, as best I recall, he explained that we were going to be engaged in this fact finding inquiry, he discussed who should be, who he should meet with and interview. I think he put together a list. He asked if we could make, if our schedules %*ere clear and that sort of thing, and that is all 244 mmB I specifically recall. When we got together over the course of the weekend the small team we would review the state of play, what do we know so far, what seems to have now -- these are the state of facts as we know them thus far. That may have happened, but I doh't specifically recall that happened or not. Q Was there a discussion at that meeting of who was to comprise the team? A I don't recial any specific discussion about it, no. Q Was there any discussion of excluding anyone from the inquiry? A I don't recall 2my discussion about that either. Q In other words , did the Attorney General mjike any statement as to I pick you folks to do this because, or give you any reasons for why these particular people were brought together for an inquiry? A No, I don't think so. I don't recall zmy. Q Was there another nteeting bout 2:00-2:30 that day? A I don't have any separate recollection of it. There may — I also — while you mentioned that, I think it was at lunch he told me I should keep a log of the meetings, of his schedule of the course of the weekend, what meetings ...^T-o Voir) an<i hr>w lona thev went and who was there. So there 245 mmm may be a note that indicates there was such a meeting, but I don't recall it. Q Why were you to keep this log of scheduled meetings? A He didn't explain why. 1 assume so we would know who we talked to and what order and for how long. I am not sure, I think it was probably at lunch, but at this point, lunch or 2:00 or 2:30 meeting, he basically -- the tasks were assigned , that Meese would be the primary interviewer. Cooper would be with him and would take notes. This may have been right before the McFarland interview, I am not sure of the time. He wanted me to keep a log of events, what was done, when. I think Saturday morning I learned that. Friday night when I went home for — I asked for the copy of chronology we had, so I could write and try to become familiar with the facts, and I think Saturday morning, he determined to send Brad and me over to look at documents. So he ws sort of deciding who would do what and making a list of people that should be interviewed, that sort of thing. I think that was the nature generally of what was going on at that point, Q I gather Mr. Cribb was out of town at this point? A Yes. Q On this weekend? 246 wKumfflT CO Q On this weekend? A Yes sir. Was there any discussion of bringing him back to help out? A I don't think so. He would hate to interrupt anybody's vacation anyway. I don't think that was discussed. Q Was there any discussion at this point Friday either at noon or if there was a subsequent meeting at 2:00, sometime in early afternoon o Friday, of whether Tow missiles that were the subject of the '85 and '86 transactions, any of them had been redirected to the contras? A I don't recall anything of that nature. I don't recall anything having to do with the contras coming up in this regard until Brad Reynolds passed me the now famous memo, when wWyfere in Ollie North's office. Q Is that a comment that you think you would have remembered? A Yes, I think I would have remembered that. The reason I do is because when I was going through documents there was mention in some of Ollie' s files of sending some Tows to ^^^^^^^^^^^^^^^^^^^^^^^^^1 That mind like crazy. In fact, I asked him the follow-up question about it in the interview and so I think, I am confident I would have remember^ such a comment. Q Do you recall at what point on Friday it was 247 0!!a«WP' c:::si8 g*rf 22 ^? 23 24 decided that someone ought to go over and look at the documents at NSC? A No. My first recollection of that was Saturday morning. Q As of Friday, you did not know you would be tasked with the next day going to the NSC to look at dociiments? A Well, that is right. I don't recall the specifically. It may have been, but I first — ray first recollection of knowing that was Saturday morning. Q We have heard testimony, of course, from Admiral Poindexter he received a call from the Attorney General around 3 o'clock that afternoon on the 21st, asking him to make documents available. Were you aware of that phone call when it took place? A I don't — well, now that you say that,- I tend to recall that somewhere in my notes I wrote down a call between Meese and Poindexter that day — 3; 05 or something — but I recall the entry, I doh't recall the subject. It is not — Brad Reynolds — I believe I an stating this accurately, recalls, knowing that we would be looking at documents on Friday, but my recollection is I don't recall that. Mine is that it was on Saturday tnoming. MS. NAUGaxeK»< If we can have this marked as Exhibrt No; 2. (Exhibit No. 2 was marked for identification.) 248 nmw 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 ' » /Q S: ^^ 23 ^!^ 24 25 BY MS. NAUGHTON: Exhibit 2 for the record appears to be a handwritte chronology type log. It begins with 20 November, '86. Is this in your hand, Mr. Richardson? A Yes. And is this the log that you kept that you were describing earlier in your testimony? A Yes. Although this, I don't think this was contemporaneously kept. It was not. I think I put it together from scrap, fro^scraps that I think you have as well. Q All right. So, why don't we mark one of these scraps now. MS. NAUGHTON: Why don't we mark this number 3? (Exhibit 3 was marked for identification.) MS. NAUGHTON: We can mark this as Exhibit 4. (Exhibit 4 was marked for identification) MS. NAUGHTON: And this one is 5 and that one is 6. (Exhibits 5 and 6 were marked for identification.) MS. NAUGHTON: This one is 7. (Exhibit 7 was marked for identification. ) BY MS. NAUGHTON: Q What I have tried to do here, Mr. Richardson, is to put the items which appear to be logs or chronologies together to both refresh your recollection and explain to us 249 miSMtBfflr CO 19 J 20 ;SSi» 21 «— ^ 22 23 24 25 ~5 what some of your notes might indicate, so feel free to refer to them as we go through them. YOU mentioned you collected exhibit number 2 from different scraps of paper? A Yes. Q Would one of those scraps of paper be exhibit no. 3. that one that is a two page document that starts off with November 21, 11:30 to 12:15? A Ves, I believe so. Q Now, I assume that that note, November 21, 11:30 to 12:30, indicates the meeting that Mr. Meese had with the President, right? A Well, yes, but I think this — it doesn't delineate when he saw the President, when he saw Don Regan, or I think he saw Regan before he went in to see the President" I am not sure how long the Regan meeting was. But that is how long he was in meetings at the White House. Q Did you ask him how long the Regan meeting was? A I don't think so. Q Did you ask him how long the meeting with the President was? A No, I don't recall, no. Q If you would turn that page over then, the next page of exhibit 3, this starts off 6:25 p.m.. AGC, JC, WBR, JR, 21 November, update. Cooper. 250 2 25 mmm 1 A Right. Was this made on the 21st of November? 3 A I think it was. 4 Q Can you tell us what this is, what your notes on 5 the piece of paper indicate? 6 A That entry I think at 6:25 p.m., Meese, Cooper, 7 Reynolds, Richardson, met on the 21st and that Cooper provided 8 an update or -- it might mean we gave Cooper and update. I 9 think it would have been the other way around. Probably that 10 is intended to show update from Cooper. 11 Then there is an arrow drawn to another circle 12 which says "6:30 add JRB," who is John Bolton --"legislative 13 update. Bolton out at 6:35." 14 He popped in and told us what was going on up 15 on the Hill. Then there was another arrow to a circle, 16 "Cooper out at 6:45." Which means Cooper left the meeting 17 at 6:45. 13 There is also another arrow saying Bolton, then a 19 star, called NSC. Tell us what that is. 20 A Okay. Well, what it indicates I think it says 21 call NSC Bolton in hearing. I believe there was a question 22 about our ability to get Bolton into the hearing that day. 23 That entry was probably made — I think the hearings were 24 Friday, so it would have been made early next day, but I am not certain. yfiCLftSSIFl[3 251 1 2 3 4 5 6 7 8 9 10 .11 12 13 14 15 17 ~^ 23 24 25 ORttliSSIFIBT I recall that there was the need to get the NSC to get Bolton the list of people who could attend the hearing. Q The name Sporkin appears. I assume that is referring to CIA General Counsel Sporkin? A Yes sir. Q Was that one of the names to be interviewed? A I think that is right. Q And then further down there is VP. A Office of OFC. Q And — A Says John Scfimidt, with an arrow to McGinnis. Q **hat does that indicate? A Well, Schmidt is in the Vice President's — he is the counsel office over there. I am not sure what that means. Probably that 5midt was to be in touch with McGinnis but I don't recall on what. Q Was there any discussion of the Vice President's office then on the 21st? A I don't recall any. What I tend to think this means is that he was appointed contact who might have done some work on some of the legal questions — Schmidt — but I don't recall specifically what that is about. Q What would :the connection be of Mr. McGinnis, who I assume is John McGinnis, OLC? A Yes sir. I don't recall. I can only speculate 252 iMSSSflBF 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 ^19 OO 21 -K«^! 22 ^;* 23 "*'■ ' 24 25 that Schmidt may have worked on some legal question that McGinnis was going to get up to speed on, or maybe Schmidt -- at some point, Chuck was trying to get John McGinnis to go over to review some materials at either^^^^^^^^^^^ I don't know if Schmidt was involved in getting him access to that. I don't have any recollection of that. Q And the other names that appeared -- Shultz, Casey and Weinberger. A Right. Q I assume those would be names of people to interview during the weekend? A Probably. Q Can you tell us why it was that Bill Casey was not interviewed that weekend? A I know the Attorney General did talk to him on Saturday. Q Was that an interview? A I don't know how you would — how you would phrase it. I was not present. Q Well, to your knowledge, then, was Mr. Casey interviewed that weekend? A I know the Attorney General met with Casey Saturday evening. I don't know how to characterize it, because I am not familiar with the details of the discussion. I would say, yes, he was Lntfixviewed emd information was, that he was DWlllStHS' asked some questions about this to add to the information, but I don't know that — that was my assumption. Q When the Attorney General reported back, did he tell you that he had asked Mr. Casey if he knew there had been a diversion of funds to the contras? A No. Q Did he report back that he had asked Mr. Casey about November '85 Hawk shipments? A I don't recall. I thinX he would have said some- thing like. Bill doesn't remember this or doesn't think this happened. That is the context in which it might have come up. But I don't remember anything specifically that Casey added or that Meese reported on the Casey meeting. I don't recall knowing that he was going to see Bill Casey on his way home. Q But as far as those two subjects which I mentioned' A No, the diversion I know he didn't say he asked him about that. I would have remember that. The other, I don't recall. Q What I want to know though, is when you are planning out these interviews, we have a very short amount of time in which to do this — was there a discussion as to Mr. Casey, as to whether or not the Attorney General would just meet with him himself or did you plan on interviewing him at a certain place and time? 1!»ASSIFIE0 254 SMttASSPIST en '' So ^ C-O 22 cj:> A Well, as I recall it, something like Meese saying I will see Bill Casey on the way home, so that took care of touching base, interviewing Casey. C Do you recall when he said that? A No, I don't. I only saw him, I saw him at lunch and probably talked to him on the telephone, but I think, I don't think he was -- well, I can't remember if he was at the department after we finished in Ollie North's office, if I went back to the department and Meese was there. I just don't remember. There is probably a note here somewhere that would refresh my recollection. I don't remember when I learned that. Q When you put Casey's name down on that piece of paper on the 21st of November, was it assumed then that he would be someone who would be interviewed? A Well, I don't recall if Casey is on Meese's list from lunch. Q On Friday? A Yes, that would be the authoritative document, because I don't have any recollection of these notes and they are random notes at the bottom of a piece of paper. It could have just been my thoughts about we need to be sure to touch base with these folks. I just don't have any recollection of that. Q Now, exhibit 4 is simply a list of meetings and 255 ina^HffT chronology. I don't have questions on that. Except one. Towards the end of those documents, referring to a meeting with Michael Ledeen on November 14 with the Attorney General. Were you present for that meeting with Mr. Ledeen? A No. I was supposed to be. Q Was Mr. Gerson present at that meeting? A No. Meese had asked me to sit in and the three of us sat down and Lepeen said I would really — made apologies and said I prefer to talk to you one on one. So I stepped out. They were in there a few minutes, then I came in. Meese told me what the meeting, he said all he wanted to do was say this and he had made and he read to me from entries in a notebook and told me what he had said, which was nothing traumatic, I guess. He said something like he had been involved in the initiative early on, that it was still a viable initiative. That is my recollection of it. Talking about the Iranian initiative. Did he explain what being involved meant? A No, I took it in a diplomatic sense. He had been involved in establishing the contacts, but I don't recall any explanation of it. Is there any reason Mr. Lepeen wasn't on the list of people to be interviewed? UNCLAuulriLl A No. I don't recall any discussion about it. 256 HSft^JSilr ^ Q Exhibit no. 5, which is one dated the 25th of 2 November '86, you said -- I just have one question -- when ^ the Attorney General tells you, apparently at the bottom, ^ regarding a phone call he got from Prime Minister Peres of Israel, saying that they did ship 500 Tows but Attorney 6 General got it wrong in his press conference regarding the 7 accounts to the contras. Did the Attorney General read this to you from a note or were you present at the phone call, or 9 do you recall how you came to put this information on this 10 piece of paper? 11 A I do not recall. I don't see any references in 12 the note that Meese got it wrong in the press conference, 13 although this nay be different from what he understood in 14 the press conference. I guess that is your point. 15 Q I don't have questions on the remaining exhibits. 16 If we can get back to the 21st. 17 (Discussion off the record) 18 BY MS. NAUGHTON: 19 Q Now, after the early afternoon meeting of the 20 21st, what did you do? 21 A The McFarlai^ interview was under way? 22 Q Yes . ,„yNClllSSIFIE 23 A I don't remember what 24 Q Did you meet later to discuss what Mr. McFarland 25 had said? 257 mteme^ A This entry in exhibit 2 indicates that we got 2 together about 6:25, Meese, Cooper, Reynolds, Richardson. 3 That is when Bolton popped in for five minutes. McFarland's interview results were probably discussed at that time although I don't have a specific recollection of it now. Q What else was discussed at that 6:25 meeting? A I don't remember anything else particularly about it. I do recall coming out of it with the feeling like I 9 ought to get my own copy of the chronology and try to become 10 familiar with the facts. 11 Q Did you do that: 12 A Yes. I think I took it home Friday night and 13 read it or stayed at the department late and read it. I 14 don't recall which. 15 Q Do you know what it is Mr. Reynolds did on Friday 16 afternoon? 17 A No. 18 Q So, it was not discussed — please correct me if 19 I am wrong — on Friday afternoon, about reviewing documents 20 at the National Security Council? 21 A I don't recall it, but as I mentioned, I think 22 Brad Reynolds does recall it, but I just don't. 23 Now, on Saturday morning, did you go straight to 24 the Department of Justice? 25 UNCUSSIFIEO 258 c=a CO 21 'WWll^lflffir Do you recall when you arrived? A Yes, it was in the 9:15 range. I rememeber I got there either just before or just after Brad had walked in to Meese' sof fice and Cooper and Meese had just come back from talking with Shultz and Charlie Hill. Q Did they brief you on that interview? A Yes. Q Do you remember what they said about it? A I don't remember in any detail. Q Do you remember if you took notes of that? A No, I don't remember. I doubt I did because Cooper had been in the interview and had taken notes of the actual conversations. So I don't think I did take notes. Q At that point in time, though, after he briefed you on the Shultz interview, did it come clear in your mind' there was a discrepancy between what Mr. Shultz was saying about the November '85 shipment and what Mr. Casey had testified to, or the draft of Casey's testimony? In other words, what I am getting at, Mr. Cooper testified publicly regarding that discrepancy and how his investigation began and so forth. Was that clear in your mind prior to the time of reviewing documents at the NSC? A I don't have a recollection of there being that discrepancy between Casey and Shultz. I do recall that it was unclear what had happened and who had known about it, and 259 imsseit ' who had known about it and authorized the '85 shipments, what- ^ ever shipments there were in '85. "* My recollection was that there was a difference ^ between McFarlan/ and Shultz. I am not myself even now 5 intimately familiar with Casey's testimony then and I don't 6 know if Casey's testimony had been based on this Scime set of ' facts that McFarlan^ had put forward. So that the answer to 8 your question might be yes, but I didn't know of it in those 9 terms. I thought the difference was between McFarlan/'s 10 point of view, and Shultz point of view. 11 It was clear to me that what had happened in '85 12 was unclear and who had known about it or endorsed it was 13 unclear. That was the principal area at that point that we 14 were interested in, because of the legal significance of 15 what had happened. 16 Q So you understood that if those shipments were not 17 authorized there may be a violation of the Arms Export Control 18 Act, or perhaps some other law? 19 A Yes. I knew legal, knew legal significance would 20 attach to whether they were authorized or not and that we 21 would have to figure out if there had been a violation or if 22 another set of legal justifications would attach — 23 Presidential, for exeunple. Presidential authority, independent 24 of the statutes. 25 But that -was obviously a worse case scenario UNCIASSIFIEO 260 mmsw ^ because that would posit a violation of one of the statutes. 2 Q What would? 3 A Well, I mean, if one relied exclusively on the 4 President's constitutional authority to conduct foreign 5 policy, for example, that as a justification that was a legal 6 justification that would only, would be a last resort, a 7 last resort, that, in other words, would you rely on the 8 statute first, if the statute had been violated that would 9 put us into a difficult situation. We didn't know if one had 10 been violated or not. 11 Q When you arrived at the — 12 A A caveat. Cooper had the main arrow on that. I 13 was a much more of a listener, note taking and trying to 14 find out what happened, so I am not even now intimately 15 familiar with those statutes. ■J6 Q When you arrived at the Department of Justice that 17 morning, I gathered at some point the Attorney General told 18 you would be going over to review documents? 19 A Yes sir. 20 Q When he told you that, did he tell you what it 21 was you were to look for? 22 A I believe, yes, I believe yes, I don't recall 23 him, I don't have a specific recollection of him uttering 24 the instructions but I knew when I went over there that our 25 interest was '85, and trying to determine if the U.S. ne -cej-j. you wnat it UNCiiSSIFIE: 261 llfffiLSSSIRffi' Government role in the shipments, whether they were authorized ^ acquiesced in, or other~wise known about, and so I had that 3 clear understanding. I don't remember him actually saying ^ this is what you look for, X,Y,Z, but he might have done it 5 I don't recall. 6 Brad and I rode over together and we probably 7 talked about it in the car as well. Q Did the Attorney General ever discuss with your 9 during this weekend his participation in the '76 finding: 10 A He probably did, but I don't remember specific 11 conversations about it. I do recall looking through his 12 schedules at some point and trying to determine where he was 13 in '86 and what meetings he might have attended of either the 14 National Security Council or the President or Poindexter. 15 Q Well, was this subsequent to January '87 that you 16 did this? 17 A No, I did that over the course of this weekend 18 review. 19 Q You looked? 20 A I looked at January ' 86 schedules over the course 21 of this November '86 weekend. yNCLASSIRE 22 Q Why was that? vii v*-i iw*** * i s*:=.^-x* 23 A We wanted to see what, to try to determine the 24 answer to the question you posed — trying to learn if Meese 25 had been at any of these meetings when they occurred, that 262 imussiaiB sort of thing. His recollection needed to be refreshed in terms of precise dates and times. I am pretty sure I did that over the course of this weekend. It is possible I did it on Monday, but I am pretty sure I did it over the weekend. 5 Q Did he discuss with you his knowledge or lack of 6 knowledge of the either August or November '85 shipments? 7 A He did discuss with me his lack of knowledge of 8 the '85 shipments. That is, his lack of knowledge of them 9 at that time and I believe in January. I think he indicated 10 that he learned about them in November of '86. 11 But he clearly, he did, clearly didn't know about 12 them in '85, That was — I don't remember him uttering the 13 words again, but I have clear recollection that he was 14 unaware. What makes me think I might have done this schedule 15 on Monday as opposed to earlier is because, when North 16 indicated in our interview with him that there was early 17 December meeting and I went back to see if Meese had 18 attended, euid he had — he was out of the country at the time 19 so it well could have been Monday. 20 Q But I guess my question is did the Attorney General 21 say he never learned of the ' 85 shipments until November 22 ' 86 or until January ' 86 when he learned of the Iranian 23 issue? 24 A I have trouble separating out when he told me, 25 because I know he did not, he has told me recently, and I ONCUSSiHI] 263 TJBKySSMfi '' can't remember how far back dating back to November of '86 2 this had been, he had told me this, but he has told me that 3 he did not, does not recall learning about the '85 shipments ^ until November of "86 and that the January '86 was the first 5 time he learned about the initiative, the Iran initiative, 6 which involved these arms shipments and that his knowledge 7 of that in '86 was prospective. 8 Q Did he tell you after Mr. Cooper's testimony? 9 A He did tell me afterward, but he may have also 10 told me that before. I believe he did. I am pretty sure 11 that over the course of this -- I have trouble giving a sort 12 of photo snapshot in time back to November of '86 and 13 remembering certain things like this when I learned them, 14 at what time, but I feel pretty sure over the course of that 15 four or five day period, Meese was operating in the dark, as 16 if we had no personal knowledge of the '85 shipments that 17 was clear to us. 13 I don't know when he told me that but — ^9 Q Let's go from that angle. An important question 20 is whether or not the '85 shipments were authorized? 21 A Yes. 22 Q Correct? 23 A Yes. 24 Q As a matter of usual course, the Attorney General 25 would review findings, for instance? imHSSIFIED 264 iffiASSiffiF A That is not — he reviews some findings, he does not review all findings. Q Which ones has he not reviewed? A Well, I don't know. The ones we don't see we are not sure about. Q Exactly how would you know he doesn't see very finding? A We made an inquiry recently of our office. When he reviews a finding normally it would come from NSC to our Office of Intelligence Policy anc^eview, who would review it for its legality and kick it down to the Attorney General 12 with a memo. ""^ Now, that was done with considerable frequency 14 under Attorney General Smith, and I had a discussion with Mary Bmj^irton, head of that office. The numbers of findings dropped off under Meese and there are, she recalled one specifically, and there may have been more findings that we found out about after they had been signed by the 19 President and we did not have advance clearance 20 21 22 office would not be involved, but there is not a process 23 place for the Attorney General to review every Presidential 24 finding. 25 That is my understanding of it. We try to, but That is conceivable that there are, that a finding IS discussed at an NSC meeting and therefore,-DaTi^hfeon.' s 265 1 2 3 end 4 mhl ms fls 5 PJtlgSffRBT we don't find out about them all the time. Q And the basis for your statement that you just made is based on conversations with Ms*- Mary Yes. ICIASSIFIEO 266 ONffiftSSIFIffiT :^ S-^ Is it based on any research with either the NSC or the CIA? A Yes, with the NSC. Q With whom did you speak at the NSC? A I have staffed that to one of my staff members, Ann Ra-iiilyaB, who when we have got -- I got two memos, one indicating the numbers of -- the findings have been signed by the President from the NSC, and another memo from Mary Lawton, a list that indicates departmental review or advice on findings and I compared the two and not all of thje things signed by the President were reviewed by the Department and there is at least one that has specifically been in our area, an area of departmental responsibilities we found out about some months after the fact. Q Did you discuss this one with the Attorney General A That one finding? Q Yes. A I don't recall, he probably — he was probably briefed on it, probably Ann Rondeau or Mary Lawton may have seen it done after we learned about it. I don't have a specific recollection of that. Q I guess what I am getting at is, what you are telling us is there is one finding that you know about from the list given you at NSC. Yes, UNCLASSIFIED CAS-2 1 2 3 4 5 6 7 6 9 10 11 12 13 14 15 16 17 18 19 Ua,J 20 ' 21 **'— * 25 ItKfiS^RIpT >r" iT/ Q That did not go through the Department of Justice procedure for reviewing findings, correct? A Actually, well, no. There is more than one that die not, but what I am referring to is there is one that we know we missed because we know we missed it, that is, they told us after it was signed, they sent us a copy. There are others of these that we have not received a copy of, but were signed by the President. Lawton's list would show me things she got a copy of, but didn't know about in advance. The NSC list shows everything signed. There is some on NSC list that aren't on hers. Q Do you recall how many more on NSC than on her list? A No, let me think here. Well, I did gross numbers, and I assume that I can reveal these numbers -- but, there were, as I recall, from the NSC list, there are a total of ^■findings since 1981 and I don't remember how these numbers divide, but I believe^^Bwere not reviewed by the Department and^^Bwere. This is 1981 through 1987. There were a substantial number, in the half a dozen range, in early 1981 which were not reviewed that may have pre-dated Smith's getting in place. One of these findings which I count amongst those that department review was the January 17, 1986 finding on Iran. That did not show up 268 mH 20 oo 21 OO 22 ■Sk*^ 24 "—^ 25 X s^ in Mary's record. I don't know if a finding at NSPG or NSC meeting was passed around which the Attorney General would have seen then. Q That is what I am getting at. A I don't know those numbers. Q Sixteen went through Lawton's office, you don't know how many actually were reviewed by the Attorney General. A That is right. But, I guess the point I am trying to make is there is no — there was a tug of war, so to speak, when Smith was Attorney General, with the NSC feeling like Justice need not review every finding and the Attorney General feeling like he did and towards — Mary tells me toward the end of Smith's tenure NSC was beginning to feel like they didn't need to and that Smith — she told Smith about it and she thinks Smith didn't get into that fight again since he was on the way out and Icbn't think that right now there is, when I asked Mary this question, do we see every finding, she said, well, we are supposed to, but there is not a process in place by which, for example, there is a concurrence block cover sheet on the findings and Justice has to sign off. But you are right in indicating that there may — it is conceivable that there are other findings in the January 17 category that Meese may have seen. She said that, for example, on occasion Casey or someone would come ov^r IMISSfflEBT .^d^ 5-7 and brief Smith orally on a finding and discuss it rather than send it over and she would normally know about that. So that number I haven't been able to determine. I am aware of North's testimony that the Attorney General reviews every finding so, in fact, that has caused me to determine if that is true. Q Are you saying Colonel North isn't totally accurate? A Well, I think his perception was probably that that was done. Q I guess we were on November 22 in the morning, Saturday morning. A Yes. Q That was a major diversion there. The wrong word, but we needed to cover that anyway. A That is right. I don't know if it is of interest;when a finding comes over, Lawton reviews it for legality, she sends a memo down, it would come to me. I would review it, ask one of our lawyers to review it, walk it into Meese and I recall in the last year-and-a-half since I have been in this position of pushing paper, two or three, two probable findings that were handled in that way. So, the volume of business that we do in that formal process is small. So I think the numbers of findings that have been signed 270 (iim^mT %^ 60 .S-5 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 iT''^ 18 — i-- 20 ^^ e/O 21 ^^23 ■I "^24 25 in the last couple of years has declined, as well. Q To your recollection, were any rejected by the Department of Justice or opposed? A I think they were. Well, Mary Lawton's notes indicate there are notations such as "advised that a new finding would be necessary", or "revision to a previous finding would be necessary", or that a finding is "premature" I gather because the activity is too far away or that this is insufficient, something like that. So, but, it is difficult to tell if the same thing was — if more information was gathered and it was later put in place, I don't have this kind of detailed analysis of them. Q Once that goes forward from the Department, then do you receive a corrected or amended copy of the finding? A I don't — well, I am sure we don't always because Mary had indicated to me and she is my source of information on this, I don't think that NSC, I don't think we have copies of the findings because my recollection of my conversation with Mary is that they don't, NSC does not feel comfortable about having copies of findings outside of their files. We have got Meese, her cover memo to Meese, I recall one specifically more in the last year where he wrote "concur" and initialed on her cover memo which she retained but I don't think she retained the finding. 271 BJWASSIRffiT ^ ^i Q You don't necessarily know if your advice is heeded? A That is correct. Although, Mary may have back and forth with either the CIA general counsel, for example, on or NSC. Just not aware of it. Q Back to Saturday morning. Do you have, aside from trying to focus on the 1985 shipments, did you have any other discussions as to what document you would be looking for. A I don't think so. My basic tasking from Meese was to look through everything that they have got on the Iranian initiative and see what you can piece together and see what you find. Q When did you know that Oliver North was the action officer on the Iran initiative? In other words, prior to this were you aware that his were the files to search and that he would have the most information? A I am sure I was before I went to the White House. Q Did you know you would be conducting a docximent review in his office? A I probably — I don't know — I assumed that the documents were — I assumed -- I guess I knew that he had most of the documents or at least a substantial volume of documents that we would review. I also, before I got there, I figured that we would not 272 IIMM$»SI&T
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7
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11
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15
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be sitting in Poindexter's office doing this. It is just --
Meese used to have that suite of offices, I know they are
two very small offices, the secretary's and Poindexter, with
a conference table and I assumed we would not be in there, so
I guess I figured we would be probably somewhere in North's
office.
Q Could you tell us then who made the arrangement
for you to actually go to the White House.
A As I recall. Cooper. Well, there was a discussion
that Brad and I would go to the White House to review
documents. Cooper called Paul Thompson, told him
Brad Reynolds and I would be coming over, then handed me
the phone to talk to Thompson to make arrangements and I
gave Thompson our names and I probably got our dates of/
birth and I don't remember if I parked in the White House,
I may have given him my license plate number, then told him
where we would meet and we went to the West Wing and met
Thompson and then he — well, with that phone call
completed, we got in the car, went on over, went up to the
West Wing, met Thompson, he walked us over to North's office
in the EOB .
Q Thompson met you in the West Wing?
A Yes. There is a West Wing basement office, which
is where I went and asked for Thompson and he came down.
I don't recall whether he walked us up to his office first
l)&iCIJC£inu__
273
iffiea^fi^'
0^
.^
or not, but I don't think so, I think we headed straight on
over.
Q Had you met Mr. Thompson before?
A I don't think I had. Although it is possible I had
seen him before when I worked in the White House, but I
don't think I had met him.
Q Had you met Oliver North before?
A Icbn't think I had, no.
Q Perhaps we put in the note already. Do either
you or Mr. Reynolds drive a Mercedes?
A That is Reynolds.
Q License number then and birthday?
A Yes, sir.
Q And that is what was given to Mr. Thompson to
gain admittance to the White House?
A I think that was given in for admittance on Sunday
morning because my recollection is I drove my car over
to the White House Saturday and Brad "rai^i^with me and
Sunday morning we met at the White House, but anyway, that is
correct, that is information I got to get him cleared in.
Q Now, when you got to Colonel North's office, were
the documents laid out or did you have to retrieve them from
shelves and so forth?
A My recollection is that when we got there Earl was
there, a number of file drawers were open, ajar, several
274
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8^ ^H
9
10
11
12
13
14
15
16
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18
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20
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25
inches, I don't recall the documents being out on the table,
although I am aware of statements that they were, but I
don't recall them being out on the table. We explained what
we were interested in.
Earl said, well, these are the terrorism files, these an
all this and that, and he was pointing at the various file
drawers.
We said we want the files on the Iran initiative.
Thompson was still there and, as I recall. Earl went
behind North's desk and North's desk was in the rather
corner of his office facing out and there was sort of
an L-shaped along the left, there appeared to be book
shelves and seemed to be a book shelf on the left and he
went under there and got out a number of what I called
"read well" folders, but sort of fiber-board, dark red
folders and laid them out on the conference table. We had a
brief conversation.
Q Excuse me, Mr. Earl went like around
Colonel North's desk?
A Yes.
Q This would have been in the area of where
Colonel North would be seated if he were at his desk?
Yes.
UNCLASSIFIED
And Earl did that. Brad and I primarily talked
275
UNfll)IS$»»ET &^ ^ with Thompson but Brad had a conversation with Thompson, I chimed in here and there, indicating what, reiterating what documents we wanted to see -- we had already said everything on the initiative in Ollie's possession that was what Earl was tasked to provide. We also asked him for anything that Poindexter had in Poindexter's or Thompson's files. Thompson responded that they really didn't have anything, that when they had documents, reviewed documents like this, they would send them back to the originating office. We asked that McFarlane's materials be produced. Thompson said that there really wasn't much McFarlane material left, there may be one box, but he didn't think there was anything in there responsive; we asked him to check and make sure. We asked him also to make sure he didn't have anything on this subject — and then I can't — I don't recai: if we asked him to run a search through their formal executive secretary system, I don't recall that. He might have indicated that would not be a real source of information because of the compartmentalized nature of the thing, I don't remember. Q Could you describe to us the System 4? A I don't think so. UNWSlilUti] 276 imtssififrr >r" i^u XS-ll 1 2 3 4 5 Q Document collection system? A I don't think so. Q If I can skip ahead one minute, I know you went to the White House Tuesday morning, did you learn about the System 4 at that time? A No, I knew from my previous tour there, I had seen documents that said System 1, 2, 3 and 4. To this day, I don't know what a System 4 document is. Q So, Mr. Thompson might have said something like it wouldn't be helpful to go through. A Yes, he may have. For some reason, I was left under the impression that the main -- the formal computerized filing system would not be a source of -- real source of information and I don't know, if the extent to which that was discussed or he said everything in this would be in Ollie's files, it could have been that kind of discussion. But that does not — my reaction is that doesn't stand out as a source of documents that we were expecting to receive. It may have been just that he may have indicated that everything in Ollie's files would be the system, whatever is in the system would be a subset of that. Q Did you ask Mr. Thompson to see a finding? A I don't think so. I don't think so. I don't recall that. jlLASSIFlEO 277 WKU^IW^ m ^ 9 10 11 12 13 14 15 16 »"v ' - 19 ^^ 22 •^ 23 24 25 Q Did you see a finding? A Well, I know I saw a finding on Tuesday. I don't think I saw a finding in Ollie North's files although Brad may have, but I don't think I did. I don't recall one. Let me put it that way. Q I have in my notes of your interview with us on April 15 of 1987, that you recalled Mr. Thompson producing the January 6 finding which has some notes in blue ink on it A Yes, that happened Tuesday morning. I don't want to jump out of sequence. On Tuesday morning when we were at the White House, Meese asked me to make sure that a system-wide search was conducted to make certain that no document containing the diversion had gone forward to the President in any form. And when I went in to Thompson's office to ask for that, there were several folders of material on his desk. I said, are these files on this, and he said yes. I said I would like to go through those, I said. He said, fine. It was in there, I saw that finding. Q Now I am confused. A It surprised me, too, because he had said they didn't keep them. That str^k^ me as odd, although not being — I just have a nodding — la^^t an intelligence professional, although I have dor|^^p)ork for that for two years now, it seemed unlikely, but possible, that North, 278 WtttHSStfSli' 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 if he were reporting directly to Poindexter on this initiative, that North was holding the file that normally would be held by someone in Thompson's position because I have been a staff officer for a while and normally Meese, for example, normally has a working file of active items that he has a couple of things that are at his fingertips that would normally be kept by his personal secretary or by me and that is why we had asked for that material, but he indicated that they didn't have anything of that nature, so I thought it was possible that North had served that function and that Thompson just did not retain paper. Thompson's office was very small. Q If we can stay on the same subject, we will have to skip a little bit, but, Mr. Sporkin was interviewed sometime on Saturday. A I think that is right. Q Do you remember if it was morning or afternoon? A I don't recall. I don't recall. Might have been late morning. I was not present and Meese and Cooper did that. Q At any rate, Mr. Sporkin did mention there was a November 1985 finding, correct, that is vour understanding IINCIASSIFIED A I think that -- I guess that is right. I don't 279 *si/raw ^ ^? 2 3 4 5 recall that specifically. Q I guess my question is, when you returned to the White House on Sunday morning to complete your document review, did you ask anybody there to see that finding? A I don't think so, no. The only person there Sunday was a young fellow who had been in Ollie's office for been in his employ for six weeks or so. I don't recall. Q Jock somebody? A Yes, a red-headed guy. Q Do you recall asking Commander Thompson at any point to produce, or if there was a November or December 1985 finding? A No, I don't think I did. Q Did he volunteer that there was one? A No. The first, my first reaction of their being such a finding was from the North interview. I may have heard it mentioned or referred to Saturday or Sunday before that, but I reacll it from the North interview. Q Do you recall whether Colonel North told you that that finding had been destroyed by Admiral Poindexter? A He did not say that. I recall that he did not say that. Q And did Commander Thompson tell you that that finding had been destroyed by Admiral Poindexter? He did not say. ICUSSIFIED 280 IWISSHF T ^ 70 Q Did Admiral Poindexter ever tell you or, to your knowledge, the Attorney General that he had destroyed that December 1985 finding? A No. Q Did Commander Thompson then leave you alone with Mr. Reynolds to review the documents, this is Saturday morning the 22nd. A Thompson left, Earl remained, and I am trying to recall, because I tend to think that Earl was at North's desk for a part of the time and if not the whole time. He might have gone upstairs to his desk. I don't recall. I wrote Brad a note or two while we were sitting at a table because he was in the room and North was in the room when we were there, of course. Q Why did you write the note? A Well, I just didn't want to mention anything that would be overheard. Q Why not? A One of the notes, I would have to see them, one of the notes concerned Brad's suggestion that we might want to just take all of these documents back to the Department and go through them and I wrote him a note back saying that is probably not a good idea. I just didn't follow there was any need for them to know the contents of our discussions. Also, didn't want 281 wmssiw^ ^ CO 20 xKaroJ' to begin a conversation with North or Earl. As far as I was concerned, I was there to do documents and the interviewing was to be done by Meese. Q Well, Mr. McGinnis went to the CIA to conduct interviews, correct? A I know that to be the case now. I don't know when I knew that. I knew I was not there to interview anybody at the NSC. Q I am going to ask that this be marked as the next exhibit in order. (Exhibit No. 8 was marked for identification.) BY MS. NAUGHTON: Q I am showing you what has been marked as Exhibit number 8. I gather that these are notes that you took while reviewing the documents on Saturday at the NSC; is that correct? A Yes. Let me flip through here. Q Directing your attention to the last two pages that you are looking at, are those the notes that you wrote? A Yes. Q To and from Mr. Reynolds? A Yes, sir. They are the second and third pages from the end. This one, the last page, I am not really — I guess this looks like the last page, looks like notes I took over there on Sunday, but I am not certain about it. 282 ilffiHfflfllffT u ^ \s-\i 1 2 3 4 5 Q Could you please read those two brief notes into the record and tell us which is "to" and which is "from"? A Okay. The first note, it is the third page from the end, '^re we going possibly to be open to attack if we take custody out of NSC of these documents? E.g., if anything, should turn out to be missing?" Q And "should" is underlined. A Yes. Q Is that your note, Tom? A That is my note to Reynolds. Q What was his response? A I think he shrugged, I think he just shrugged and agreed that we wouldn't take — he had suggested it would be easier to if he just took all this over to Justice and I -- this was a large volume of material and I was not comfortable taking them out of the office where they were produced because if we had misplaced a document or something like that and it turned out to be an important one, we would, just having gone through the move, I was worried about our being subject to criticism for there being a missing document. Q And the next? UNCLASSIFIED A This did not contemplate in my mind that documents were being destroyed. It was in the other direction. I didn't know if everything had been produced to us, that is ywumi^ 75 >r what that was about. The next one? This is the second page from the end, "we could use night to catch up with Chuck and I can come here early in a.m. to finish this. Then meet you guys later in the day." 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 fimmiB 284 BNftl^MdT >^ 7*/ " 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Q Now, the first note that you passed to him, was that in the morning? A This was probably pre-lunch, yes. And the second note was probably after lunch when Ollie was in the office. Q So, when Mr. Reynolds found the famous diversion memo, for lack of any other name for it, that was prior to Colonel North coming to the office, is that correct? A Yes. I think it was after this note but I believe this note about taking custody of the documents was pretty early in the search. Q Could you tell us what you recall about that event, that is. A The diversion memo? Q Yes. A He either kicked me under the table or something and we were sitting across from each other about the same distance you and I are now, just a foot or two, and he passed it over, directed me to at the top paragraph and had an expression of this was a surprising entry. So I read it and 1 gave a similar look back and I think I probably said something like that didn't happen or something along those lines, that's hard to believe that had happened and passed it back to him and then that was it, we did not discuss it at the time and 1 don't think Earl KUSSIEIOL 285 llHKI\SS)Qii:T %y noticed anything particular about it. Every once in a while I was going through some documents I would point out something to him, that sort of thing. But that was clearly the most interesting document we had seen. I should add my statement was based partly on the fact on page 1 of the document there was a handwritter correction and that sort of thing. My first impression was this is too spectacular to think it happened and there is no reason to believe this is a final document so that sort of incredulity was my reaction. Q Do you recall if you had seen any other versions of that? A I did not. That referred to the contra diversion? Q No, any other version of that, version of that memo. A There were other memos that discussed the initia- tive but I don't recall anything that looked like a version of that. Q Do you recall any other memos that mentioned diversion? A No. Q Do you happen to know where that memo was in terms of the other documents around it, in what file? A No; Brad found it and I just don't know. I think 286 H it was in '85 material because before lunch Earl had not produced '85 files and in fact when we were leaving we passed North in the hall and we told him that there weren't any '85 files, he expressed surprise and said I will get them out for you. So it was in '86 material but I don't remember which files. Q Do you recall when you were first shown the material by Commander Thompson? Do you recall any files in North's office regarding the Nicaragua resistance or Central America? A I did not see any. I don't recall — it's conceivable that Earl said these are all the files having to do with the freedom fighters but I don't recall that. He did say these are terrorist files, this is a hostage file. We said we want everything on the Iranian initiative and because they pulled open one drawer and said these are all the reports from the hostage ^^^^^^^^1, and that had to deal with where they were and we said we weren't interested in that. I don't thinX we discussed or saw any files concerning that. (Short recess.) BY MS. NAUGHTON: Q Okay, back on the record. Do you recall how soon it was after the diversion memo was found that you folks broke and went to yNCLASSIRED 287 mmm lunch? 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 A No. I don't remember precisely. I think there was a substantial period of time after it was found before we went to lunch. Q Do you recall about what time you went to lunch? A Just from the note that I saw a minute ago, it was Exhibit 2, which indicated 1:45 to 3:15. I do recall it a late lunch, this wasn't noontime. Q Could you tell, describe for us of the documents that you wanted set aside or copies or somehow preserved, for you, could you tell us how you did that procedure, how you work that out? A Well, as I recall, Brad was, I may have done this, too, but I know he was using paperclips to mark them. I tended to think I took over with me, but I may not, I may have been using paperclips, I tend to use those yellow stickums, they were marked one way or the other. Q Were they put in a separate pile? A I am not sure. Q At any rate? A This may have been turned sideways in the same pile they were somehow delineated. Q The ones that you wanted to copy? A Yes, sir. |ift|| 1,»/ 288 URSIftW^T &<r Q Was this done, do you know, with the diversion memo? A I din't know. I am not sure what Brad did with it. Q Were any documents copied for you before you left for lunch? A No. Q But I gather you had set aside some documents for copying by them. A Well, yes, we had marked some documents as being ones we wanted to keep with us, take with us copies. Q And when you left was Colonel Earl still there? A Yes, sir. Q Do you recall that morning what discussion you had with Colonel Earl, if any? I know you said you didn't want to interview him. Did he make any comment? A I don't think he made any comments. He may have said something like let me know if I can get you anything or be of assistance, but that was, other than I think he indicated pointed out which documents were in which files and produced the things behind North's desk, that is it. Q Did he participate in any conversations on the telephone or otherwise in your presence that you overheard? A I don't think so. I don't recall any. !1 289 IRtMflfflr >*" He did have a conversation with Thompson. Thompson asked him if he knew where Ollie was and Earl said I have been trying to reach him, but I think he is due in soon, or something like that. Other than that, I don't recall any conversation and I don't recall him taking any phone calls. Mr. Thompson came in later in the morning asking for Colonel Earl, that was when we arrived. I missed that earliei Q Do you know whether or not Commander Thompson left after escorting you to Colonel North's office. A He left North's office, I don't know what he did. Q Did you see him later that day? A I don't remember. I don't recall seeing him again that day, or Sunday, for that matter, but I may have. This is Thompson? Yes, Thompson. What about Craig Coy, was he around that weekend? No. What about Admiral Poindexter? I gather you didn't Q A Q A Q see him. A No, I didn't see him. I got the impression — well, no, in fact, I guess it is more impression. North talked to Poindexter. That is the impression I got when North was there. Q That was in the afternoon? ONClASSintB 7^ 290 owsasaBiST >^ A Yes. Q Do you recall what he said to Poindexter? A I don't think so. Let me see. I made a couple of notes at the bottom of one of these. No. I am not sure, my recollection is after that North had a conversation with - he had a conversation with an Israeli. I think he then had a conversation with Poindexter. I don't recall. I think he called over and said, is he still there or something like that. Then he talked to someone. I gathered it was Poindexter, but I don't know if he said that was Poindexter. Q When you and Mr. Reynolds left for lunch, did you tell Colonel Earl you were going to lunch? A Yes. Q Did you tell him you were going outside the White House complex? A Probably. Meese had called and said he wanted us to meet him at Old Ebbitt. I probably told Brad that in Earl's presence. We may have said we will be back in about an hour or something like that. I don't recall. You can't eat in the White House, there are some machines in the basement of EOB , but you can't eat in the White House mess unless you are a member. I think he would have known that we were not going to eat in the White House. Q Was Alton Keel at the NSC on Saturday? !!MClJiNMi-itis__ 291 BNft^fflffiT ^ 18 CSS th^ 20 5*:^ 21 c^ A I don't know. Q And did Colonel Earl mention what his lunch plans were? A No. I don't think so. Q As I gather, as you were leaving to go to lunc^ you met Colonel North; is that correct? A Yes. Q And how did you know it was Colonel North? A I don't know. I guess Brad and I came out of his office and we had walked probably five steps and I believe he said something like where are you guys going or something like that as a greeting and I don't know if Brad had met him before, but I had not, and introduced myself. I think Brad introduced himself, too, now that I think about it. Q Then my question, how did you know that was Colonel North? A I guess he assumed that the two guys leaving his office were the Justice guys and he introduced himself, as I recall. Q Did you tell him you were going to lunch? A Probably did. He said where are you guys going, have I missed it, or something like that, and we said, we probably said we were going out and have a bite of lunch. 292 BNRlgSfflff' to be interviewed? then we would be back shortly. I don't remember precisely. Q Did he volunteer at that tir A No, that was later. Q Was there anything else said in that brief meeting? A Brad told him, yes. Brad told him we had not seen the 1985 material and that we wanted to see that when we got back from lunch. What we were looking at was 1986 material. Q What did North say? A He said something like, oh, that should have been in what you were given. I will be sure that you have got it or I will find it, something to that effect. Q Was that produced by the time you came back? A Yes. I don't remember if it was on tbe table or if he — I think it was — he had pulled it out and he said this is the 1985 stuff. Q Along those lines, in your document review of 1986 materials, you saw what we know now as PROF notes; is that correct? A I don't know. I may have. Now, I don't think since the name PROF note had been attached, I don't think I have gone back and looked at one. Q Do you know whether or not either you or Mr. Reynolds discussed with Colonel North whether _he had PROF notes from 1985. ilNCUSSIFlEe 293 itmimirr 6*" :as-5 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 -™^ 18 ±Z ^® X3 20 sac 21 Lr> 22 g 23 24 25 A I don't think so. I don't recall any such discussion. Q Can you tell us what happened when you got to Old Ebbitt? A Well, Meese and Cooper were already there, as I recall. They seated us shortly, and I think Meese began by saying, all right, let's see where we stand and he and Cooper reported on what they had been doing and I don't remember independently what it was. Let me see if this -- I don't have an entry on my notes on Exhibit 2. But it may have been the Sporkin interview that may have been after lunch, I don't know, but they reviewed the state of knowledge based on what they had learned and he said, well, have you guys learned anything new, and I think we -- I told him I had been looking through ^^^^^^^^^^^^| told him one of two things that seemed to be of interest from those and Brad did the same thing, and Brad said, oh, we found another document which seems to indicate that funds might have gone from this transaction to the contras, and I mean Meese expressed great surprise. He visibly said something like, oh, a curse word, and sort of squinted his eyes and that sort of thing, and we said something like we haven't found -- Brad indicated we haven't found anything else to indicate that happened, and Meese said, be sure you bring a copy of that out when you come, and we said, we are marking things 294 ums»«ET >« ^y to copy, and I think that was it on that front. Cooper may have said, there may have been comment like if this happened, we have got a major problem, but that was sort of obvious. But it was very, very much - the context of the information was very much incredible prospect and clearly uncertain whether this had occurred or not. Q Was it discussed, the fact that Oliver North himself had the Central America account? Did you put those two things together? A No, I don't think so. I don't recall that, but I don't think it was. Although I am sure -- I may have known that and the AG, I guess, he would have known that. I think I may have known that because of when these matters have come up before, Ray Duon, our staff who handles that sort of thing might have said Ollie North handled this business. So it may have been just a piece of knowledge that we had, it wasn't openly discussed. Q Now, just for the record, so we get a couple things straight, I gather at that luncheon you did not have copies of the memo with you. A That is correct. Q What else did you discuss after mentioning the diversion memo and what you just related, what other subjects emssiFiED 295 BNRISSfffflT ^ M were discussed. A Well, I thank that the ma^or things of interest still focused on what was going on in 1985 and who did what, whether this was authorized, et cetera. I don't remember with any specificity what the contents of that discussion was, but I recall that we, the diversion discussion, was ^ about what I have recounted, the basic information and there 8 may have been some statement that this will be a -- 9 this obviously is a major problem, if this has happened, ''0 we need to find out if it has happened. There may have been 11 a mention that we -- North would be interviewed -- at the 12 bottom of this in the North interviews, something like that. 13 That was it on the diversion business and the rest was 14 spent talking about the arms initiatives and Chuck, for 15 example, he might have -- there were other things going on 16 like McGinnis having gone through^^HH^^^^^H and I 17 don't know if he was at CIA that day, but Chuck having some point -- Chuck and Meese, I think, split up and did 19 some different things. So I am not sure what was 20 precisely we talked about, but it was other things. 21 Q How did you know that North had authored the 22 diversion memo? mm. 23 A We didn't. mmm 24 Q Why did you feel you should interview him? 25 A He was going to be interviewed anyway. This was 296 wsimm f^ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 btd 19 CO ^° 0<5 21 > 22 !^I^ 23 25 found in his files and so the most likely person to have knowledge about it was him out of the pool we had identified thus far. Q Was there a discussion at this point that Poindexter should be interviewed? A I don't recall that. Q How about whether Casey should be interviewed? A I don't recall there being a discussion about adding anyone to the list or subtracting anyone from the list or targetting the interviewing any differently other than our having a clear understanding that this would be something to question North about. Q Was it decided whether to question anyone else about it? A It wasn't discussed in that context. We didn't say, okay, now about the diversion, who do we question. It was something found in a document that might or might not have happened, next step to finding it out, get a copy of it and ask North about it in his interview the next day. That is as far as it went in terms of that point. Q Was it discussed whether it shouldn't be mentioned to people who were going to be interviewed? A No, I don't think so. I mean, it was clear that we weren't going to say anything about any of this to anybody outside of our group of four. I don't recall that being 297 HNSMtHIST 9 10 11 12 13 14 15 16 17 18 19 end 2B 20 21 22 23 24 25 reiterated, but that was a very -- that was very clearly understood. Meese might have reiterated it. I know at the beginning of the weekend, it was made clear that — we, three of us, were going to work in support of Meese 's fact-finding inquiry, we were to talk to each other and obviously -- I mean the potential significance of this bit of information was not lost as a major development in this fact-finding question. Primarily for — at this point it was a factual bomb shell and whether it could possibly have occurred or not these are obviously to the President's two major and independently controversial initiatives and so that was not lost on anyone, there was no substantive discussion of it at this point because we didn't know if this was just a plan or a possible way to go or if it actually happened. As just in percentage of conversation at lunch, this was a small percentage, five minutes or less. Probably five minutes. It grew in time over the course of the next several days. 298 Bob Thomas ' -t-l .«sr^ CO 21 mwH^fi^T j<r Q When you went back then to the NSC, was North in his office? A I think he was, yes, I think he was. Q That would be at what, 3:00 probably, in the 3:30 range, 3:15 you said. A That is probably right, when we probably left lunch at 3:15. It was in that neighborhood there. Q Did Colonel North mention to you where or with whom he had had lunch? A No. Q When you did get back to the NSC, did you know whether or not any of the documents that you had set aside for copying had been disturbed in any way? A No, everything, everything looked as we had left it. Q One more question about the lunch, was it discussed at lunch or even generally on the way over to the NSC that something should be done to secure the documents? A Well, we discussed getting copies of the documents. Q But was there any discussion of securing them? A Any what — Q Being sure they weren't destroyed. A No. There was no reason to believe that they would be or that they had been for that matter. Q Was Colonel North at his desk when ycu returned? A Well you have to be, — to get into that office you 299 UNSkASSlEKKT y: U) have to be let in because there is a vault on the door. He, as I recall, I think he let us in. We rang the visitor's but- ton and he went to his desk and we went to the conference table. Q I trust that you began to up your interview of docu- ments? A Yes. Earl was still there by the way. We asked him, we told him we wanted to make copies of some of the documents. He said fine. He said, do you know which ones? Do you have some you know you want right now? We'll help copy them. Yes, these we know we want. He and Earl helped copy what we had up to that point. When that was done — Q Colonel North and Colonel Earl helped you? A Yes, that is my recollection. Then after we had copied that group, I took over all the xeroxing from that point on. Earl left at some point fairly soon thereafter and North took a portion back behind his desk. A So do you recall was it you or who copied the diver- sion memo or would it have been Earl and North? A I don't recall who copied it. Q Well, did they copy everything that you had set aside that morning? A I think so. What I don't know if Brad held out the diversion memo and then gave that to me to copy. I don't recall when, who actually copied that memo. !liaCli.<{.?lFJLn 300 0W8H^flf?:T ;«" Q Now, I had one question of your notes here of the documents that you had reviewed. You reference As underlined. Is that a person? A I think it looks like it is, yes. In entry nu.Tiber 1, there is the word beginning with capital A and then the rest of it is blacked out, and K, and the rest of that is blacked out. So, I probably was using the initials not want- ing to write down the names because there seems to be, there IS an aside and a quote, it is probably some individual. These are, I think, notes' Q Do you recall who that could have been? A looked ^^ ^^^^^^^^^^| ^ could you but — does the name ^^^^^ring a bell? That sticks in my mind for some reason. I don't know who it was. It was some- one in Q Okay. A I gather there was a^Bperson too, but I don't know. After awhile I stopped taking notes on each document because it became too time-consuming. Q Now, if we could sort of take the rest of your docu- ments and review a couple. I gather you didn't come across any other documents mentioning diversion of the monies to the contras; That is right. ilNCLSSSIFIED Did you find any document which indicated that the DttJH^I^IlT M- November 1985 Hawk shipment was authorized? A Yes, well the document that contained the reference to the diversion, I believe, the second paragraph it said something like the U.S. Government endorsed the September 1985 shipment and that I specifically recall that one. Meese, in fact, that was the principal angle of questioning that Meese used on North when he showed him the diversion memo at first. I specifically recall that. I don't, I tend to recall that there was reference in, maybe, in^^^^^^^^^^^^f the Septem- ber 1985 shipment being connected to actions on the part of the United States but that is a fuzzy recollection. Nothing else specifically stands out in my mind at this time, but there may have been back then. Q And of the comment regarding the Hawk shipment being endorsed by the U.S., did you discuss that particular provi- sion at the luncheon you had? A Well, that was actually the September shipment. I think those were TOWs. But I don't think we did discuss that at lunch. I don't recall but this is surmising because I had read only the diversion section of that memo I think. I might have looked at this section. We got the copy of this memo at the end of the day and I know we went over it in great detail with Meese before the North interview. We probably didn't go --didn't go over it in that much detail, although Brad might m\:\ 302 IHKU^j^T SLK-5 1 2 3 4 5 have mentioned it was in there, I don't recall. I know there was a discussion about it on Sunday afternoon before North's interview. Q During your document review on Saturday afternoon, can you try to recall, please, everything that North had to say to you? A Okay. Well, I recall that he had a conversation, that is in the note that made in Exhibit 8 at the bottom — Iguess I will count the pages--bottom of page 7 I have written a G in a circle, drawn a line across the bottom, received call from Israeli code talk nephew and then a swiggle line said lots came out, lots not, mos sens, not so still talking. Then that was referred to a North call that he had with some- one that I could tell was an Israeli because he said, did you see, he referred to an article in the New York Times that day or the day before that mentioned Kimche, he mentioned this article in the New York Times to this gentleman on the tele- phone. He said things like your government, everyone in your government and my government is overreacting or panicking or something like that. The code talk and nephew, he mentioned a nephew, the code talks you don't remember if that I ran across the code which had a key for names and that sort of thing, I don't remember if he was using something like that, but he mentioned Beethoven and composers, I think he might !^l<;SlFlfJL. UMA^WSlET ^ have told us that Poindexter was Beethoven or I saw that, I remember that. But he told him that a lot had come out about this initiative already but a lot hasn't, that the most sensitive things have not come out. I think that is what my note means here so they are still talking. There was another, second note I have got, Bremer mentioned phone call. I am not sure what that is about. He didn't — I just don't remember what that is about. He mentioned the Ambassador on phone call but I can't remem- ber more about it. I think, the only other recollection I have got is that he placed a call which I thought was back to the West Wing and asked for Poindexter after he talked to the Israeli. He left the room one time to make a pot of coffee. He offered us coffee, and I followed him out of the room, went back while he made coffee. We talked about Marine coffee and how bad it was and that his wasn't much better, that sort of thing — and he came over and, this is over the course of the three hours, I don't remember the sequence, but came over at one point, sat down, and said, all right shoot, let me know I'm ready to take your questions or I guess you are ready to ask them, something like that. We explained that we were just the workers who were going to go through some of the documents and that the AG would ask him some questions tomorrow. limiASSIREO 304 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 yM«S ET 1^ And, at some point there was a telephone call from Meese and my recollection is that Meese talked to me about setting up the time with North, he said, could you see if I could do it in the afternoon instead of the morning because that is church time with the family, we go to Roy Rogers afterward, that sort of thing. That could have been a direct conversation, but I think I was the person who talked to Meese then talked to North. Q Hold on for a second, was it a case of the Attorney General placing the call, putting him on hold while he talked to North and then speaking to him, or did you place another call to the Attorney General? A I don't remember. n 'mmm 305 IM«MlfflBT 95 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 A I tend to think. I put the AG on hold and asked him, but I just don't recall specifically. I mean, it is possible also that the AG called and aid, "Let me talk to--put Ollie on," and that I overheard Ollie saying, "Well, could I come in the afternoon." I mean I could be wrong on that; but that's just my recollection. At another point, he said something like--you mean he was passing the time of day and he said something to the effect that there aren't that many poeple around the govern- ment who are at work at this hour like us that are working these extra hours and that sort of thing. He may have said something— I know at some point he talked about the initiative and the purpose of it. He said people don't understand what it is all about, but this was a broad-based initiative or something, more of the diplomatic reasons. And he also — I just remembered one thing and it slipped through my mind. Q How about his remark of being a fall guy? A Yes. He didn't use that phrase, as I recall, but he did say something to the effect that— I mean, he was very friendly and outgoing and— I mean he gave the appearance of being relaxed. But he said something like well, I'm not worried, in six weeks I'll be commanding a Marine battalion of infantry troops, or something to that effect, that I won't be--he knew he would not be long for this job, something to that effect. UNCLASSIFIED 306 « 96 SLK-2 1 2 3 4 5 6 /7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Q Anything that you can recall? A The last thing I recall — I'm trying to think if there's anything in the office. I know when we were leaving, we walked out with him from the building into the parking lot, and walked Ollie — Ollie got into his car, just like, as I recall, just like a red and white wagon, a Bronco; and Brad and he were talking about their daughters mutual interest in horseriding and the strain that put on parents. I think that's about it. I don't think there's anything--nothing else I recall. Q Did he mention to you that he had consulted with an attorney, or that he had an attorney? A I do not recall him saying anything to that effect. Q Did he say that anyone had advised him to obtain an attorney? A No. I don't recall anything about that. Q Did he ask either you or Mr. Reynolds whether or not you thought he should have an attorney? A I don't think so. I don't recall that, and I don't think he did. Q Did — A These are the kinds of things I think I would remem- ber, but I don't. I mean I can't be certain that they didn't occur, but I think I would remember them if they did. Q Did either you or Mr. Reynolds advise Colonel North yMciij;sififiL_ 307 mmm 97 to get an attorney? A No. I certainly didn't, and I did not hear Brad recommend that. I mean to give — the nature of the thing was that there was a major political problem in terms of — it was clear there was a major political problem with this initiative having been made public and the policy seemed to run counter to previously stated Administration policy, and it didn't seem unusual at all to me to hear him joking about losing his job. As being a — and I didn't know whether it is because he was a proponent of or complementor of the policy. That didn't seem unusual. There was not any flavor or feeling of he hdd personal legal liability. Although, I mean, we were clearly aware of legal problems for the Administration. Q Do you recall what time you did leave in the company of Colonel North? A I saw a note here a minute ago that seemed to indi- cate it was — yes. On Exhibit 2, it indicates 7:15, JR and WBR depart NSC offices. That's probably about right. I don't think it's contemporaneous, but that's probably about right. Q Did Colonel North mention he was going home or did he have another engagement that evening? A I don't recall. I don't think he mentioned another engagement. I mean, I think we — I recall him saying he lived in Great Falls and I may have said, because they were talking about the horses. I may have said I live in McLean, you have 308 UHttlfiSHlfeT 98 a long drive, or something like that; but I don't recall knowing where he was going. Q Did he mention any meetings that he had had or planned to have with Robert McFarlane? A No. Q Did he make mention of Tom Green? A No. Q Did he make mention of Richard Secord? A No. Q Did he make mention of Albert Hakim? A I don't think so. No. They were all mentioned the next day during the interview. Q Sure. Now Sunday morning, do you recall when it is you went to the Department of Justice? A Well, I came straight to the NSC. Q Oh, okay. A From home. And I overslept because I got in there later--! think we had Jock in there at 9:00 or 9:30, something — we wanted him to meet us around there at that time. It's just my recollection. And my note here on Exhibit 2 indicates I got in there about 10:45. I stayed up very late the night before. Q By the way, when the copies were made of the docu- ments you wanted, did you take possession of them? OMCliSSlfJEL.- 309 u 99 A Yes. Q Where did you put them? A Well, I kept them in a pile next to me while we were in the office. Then I think I got one of those legal size fiberboard folders and put them in there when we left. Q Okay. And where did you take them? A Took them back to — well, I don't remember if I went to the Department. I probably went to the Department after leaving the NSC. And then I took them with me--I mean, they were on me at all times. I took them home. I don't take classified material home normally, but — I mean I locked them in my trunk when I drove home. I took them inside and put them under my bed. I lived in a one-room place at that time so they were within arms reach. I am sort of paranoid about classified material anyway. Q I take it then you took them back with you when you went back to the NSC? A Yes. I probably had a litigation case going or coming. I tend to recall that I did, with notepads and-- that's why I think I used stick- 'ems to mark my documents. I think I had one of those with me. Q Do you recall when it was you went from the NSC to the Department of Justice? A I think it was around mid-day. Let me see if this refreshes ray — Exhibit 2, the note for 2 3 November indicates iiSlASSlEIIL 310 SLK-6 1 2 3 4 5 100 12:40 to 2:00 p.m. that we met with Meese and Cooper, Reynolds and myself. So we probably left there about 12:00, 12:30. Q And during that meeting, you mentioned that you went through the diversion memo? A Yes. Q Carefully? A I think that we showed it to Meese for the first time then. Q Had you seen typewritten questions prepared by John McGuiness? A I think I saw them at this meeting, at this pre-Nort meeting. I think Cooper went through them with Meese. Q When did you first discuss the weekend inquiry with John McGuiness? A Golly, let me think. May have been Friday night. I went down to see Cooper and knew that John was involved. I didn't sit down and talk to John about what we were find- ing or the state of play. I did not brainstorm with him or share any information that I had gotten with htm. I know there's a set a notes that I took after a conversation with McGuiness, and I don't remember what day. Maybe Monday, where he told me what he had learned at the CIA; and I am sure there came a time when I knew John knew about the diversion pros- pect and a fuller conversation was had, but that could have been Tuesday as opposed to sooner. I don't think that I knew iMyccjMD. 311 iiNsyi$sia£iT
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McGuiness before this weekend. I knew Cooper trusted him and
that he was — is a very good lawyer and a very confidential
person to deal with this kind of sensitivity as well as
classified material.
BY MS. NAUGHTON:
Q I show you what has been marked as exhibit nximber
McGuiness on the 24th of November, 1986?
A Yes.
Q And it indicates 1:30. Is that when the conversa-
tion took place?
A Probably — yes. That's probably what that means.
Q Can you tell me what the first reference is to?
A The entry says, "Rumors at CIA extra money" — a
dollar sign — "paid to" — its Southern Air Transport. It says,
"SO Transport." and "funneled to Nicaragua."
Q Now when he hold you this, were you — in other words,
bigger, meeting?
A I'm pretty sure this was one-on-one. I don't know.
We might have been in Cooper's office or we might have been
in my office. I don't know which.
Q Was Cooper present?
A I don't think so. I mean it's possible, but I
would tend to thinX not.
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Q Do you know whether or not Mr. -Mefiujaitss told you
that he had told Cooper this piece of information?
A I don't recall. If he had not, he certainly would
have the next moment I saw him because I mean he was reporting
to Cooper; so I think he was bringing me up to speed on what
Q Did you bring this fact to the Attorney General's
attention?
A I don't recall. I may have. What is more likely
is that Cooper briefed me on what McGuiness learned at CIA,
or from talking to the CIA people. But I might have; I just
don't recall.
See, at this point, — well, this is a slightly
different twist on contra funding because it seems to indi-
cate the ruitiors at CIA were the money was funneled through
Sourthern Air Transport. But my basic point of view is that
well, we already know that money has been diverted from the
contras and this would go to the how — but I would think
Cooper was the one who would have briefed Meese on this.
Although I may have done it.
Q When McGuiness told you that this was a rumor at the
CIA, did you tell him at that point, well, we found a memo to
that effect at the NSC?
A I don't think so.
Q And did you tell him about the North interview:
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A I don't think so.
Q Why not?
A I just was not telling anybody outside of the other
two, three people including the Attorney General that I was
authorized to tell people — tell things to. I knew that Chuck
was tasking John to gather certain kinds of information and to
look into certain legal questions, and I wasn't going to take
it upon myslef to share that information with anyone. Not
that I didn't trust — he may have known. I just don't remem-
ber. Cooper may have told him by this time, but I don't recall
But I'm pretty sure that I did not volunteer it.
Q Prior to the Attorney General's press conference of
November 25th, did you tell anyone at the Department of Jus-
tice or outside of the Department of Justice —
A No.
A No. The only possible person would have been
fKGUlKBss-, and I'm pretty sure I didn't tell him.
Oh, I take that back. I told Ken Cribb. Cribb
came back into town probably Sunday night. I don't know for
sure. Monday morning— actually , I think I called Cribb at
home Sunday night and said we are meeting with Meese at 8
o'clock or— I think it was 7:30, maybe, 7:30, a quarter to
8, we arranged to meet with Meese. I asked Ken— I said, you
should be at that meeting. I went and caught him in his
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office five minutes before the meeting and brought him up to
speed. I mean up to speed in terms of the bombshell prospect
not in every detail. And then I think Ken went — I believe h«
was in that pre-8:10 meeting, but I'm not certain. I think t
was. But Ken was added to the list of people who knew. i
better think for a minute so I make sure I don't miss anythir
else.
I think that is it. I did not tell anyone else be-
sides Cribb.
Q Are you sure? Or do you just think?
A I am pretty sure I did not. As I say H e Guineo s is
a possibility, but — unless M e Ouinog s has raised it with me,
I would not have raised it with him. Now he may have raised
it with me, but then I wouldn't have told him, so I would saj
that Cribb is the only one I told.
I don't think, for example, I told Meese's secretary anc
she was there all weekend. So I think that's right. I'm
pretty sure Cribb is the only one.
Q What about anything else outside of the Department
of Justice?
A No. I'm not married and I don't think I would hav«
told my wife anyway; but that would be the only possibility.
Q If we can go further now through Exhibit 9, rumors
that.
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A Second entry, "CIA did not use" — it says, "SO
Trans," T-R-A-N-S, which is Southern Air Transport — "in this"
—underlined this— "transaction (Nicaraguan or Iranian ship-
ments. ) "
Q What does that mean?
A I gather it means that the CIA did not use Southern
Air Transport. I^m not sure what "this* underlined refers to.
It may refer — I mean, it may refer to — in fact, it must--when
I look at the next entry which says, "All arrangements NSC
Bud November ' SS^^^^^^^Hand November '86 replenishment,
'.' I gather it refers to the — probably to the
November 1985 shipment. I hesitate because at some point, I
have the recollection that a Southern Air Transport crew
was used for something, but I don't know where that fits in.
That may have been 1986 shipments. But I think our attention
here was on November 1985, which was ^^^^^^^H the proprie-
tary.
Q Were you aware during this weekend that Southern
Air Transport was being investigated after the Hasenfus
crash?
A I don't think I was.
Q Were you aware of the call by the Rouse Judiciary
Committee members for an independent counsel to investigate
that?
A Well, I was aware of — let me think for a second. I
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was aware of Congressional requests for investigations of
drugs, alleged drug smuggling by the contras. Now I don't
know if that's the same —
Q No. There is a request on October 17th, 1986,
following the shoot down of the Hasenfus plane at which a
majority of the House Judiciary Committee members asked for
a preliminary investigation into whether or not an independent
counsel should be appointed to investigate that particular
activity;
A Did they name an NSC member as the target?
Q Yes, it named North, it named Poindexter, it named
Casey, it named Vice President Bush and others.
A I was probably aware of that but not — I did not
think of it this weekend. I did not — I mean, I was probably
aware of such an allegation or a request. I would have seen
the letter when it came in to Meese; and I probably would have
known that something had been referred, but I don't think I
knew that the entity involved was Southern Air Transport or
that I put the two together.
Q I guess we skipped ahead to Monday morning. I
think those are the relevant things from the M c Guiiiesb .
A Yes. Okay. There's a reference to fair market
value. We were trying to find out the price of the weapons.
Q What's that last line?
A "NSC paid (or intermediary for Israelis et cetera)
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for Southern Airways."
Q Okay. If we can get to then I guess the North
interview.
A Yes.
I gather Colonel North came alone?
A Yes.
Q And this took place in the Attorney Generals 's
office?
A
Q
A
Q
A
Yes.
Were you the designated notetaker, as it were?
Yes.
You had decided that prior to the interview?
Yes. I mean, it had been decided for me, but yes.
I knew I was taking notes. Let me put it this way. I think
Cooper was tired of taking notes and Meese — he thinks I'm a
decent notetaker.
Well, you have one of the best penmanships of any-
one at the Department of Justice. I can tell you that from
personal experience.
A
Q
of you.
A
Q
Thank you. Except Meese 's, his is very neat, too.
In fact, sometimes it's hard to distinguish the two
Yes.
Did Colonel North mention at this interview mention
having consulted with an attorney or having an attorney?
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A I don't think he did.
A No. I don't think he was.
Q Was he told he had a right to have one there?
A No. I don't believe he was. I should just, as an
aside, on any specific thing, if my memory can be refreshed or
corrected by looking at the notes, I sort of reserve that.
I go by recollection on this line. It may be incorrect in
some detail, but I think on those none of that happened.
Q Okay. I really did not have specific questions on
the interview.
A Okay.
Q But I think Tom does. If you want to jump in?
MR. McGOUGH: Want me to do them now?
MS. NAUGHTON: Yes.
BY MR. McGOUGH:
Q I only brought one copy of these because I didn't
intend to introduce them as an exhibit.
I wanted to go to that portion of the interview
where the Attorney General raised the subject of the diversion
A Right .
Q As I understand, the way the interview went at — it
proceeded on a general level and for some time, or at least
it didn't deal with the diversion for some time, and then the
Attorney General brought out the diversion memo and began to
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109
to go over portions of the diversion memo other than portions
referring to the diversion itself?
A Right.
Q Is that right? Fair to say?
A Yes. I mean — and I think — I mean, that was a tacti-
cal determination. He established that North had written
the memo and he drew his attention to what was genuinely
new information or — on the question of enforcement by the
U.S. Government of that September 1985 shipment which was
on page 1 .
Q One of my questions is was that a tactic discussed
lengthy meeting before North C2une? Were there tactics dis-
cussed? How you were going to broach it?
A I don't recall that specifically. I do know Meese
was talking about what areas to cover; and using the typed
questions that Cooper had provided. He said, all right, we
want to go through the 1985 shipment; well, how the initiative
concerning the use of funds. But I don't recall him specific-
ally saying now — if he~he did say, now I will do the question
ing. And if you've got anything to add, you let me know.
But it was clear — I mean, it was very obvious to me once he
began the questioning what he was doing. You may know this,
but he had been a prosecutor for eight years in his early
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career. So he's--he's a good questioner.
Did you know going into the meeting that the Attorney
General might have to leave early?
A I think I did. His wife was coming back from out
of town and he had to go pick her up at, I guess, the train
station or--either there or the airport. I think I knew,
but I'm not--I don't recall clearly.
Q Now there's been some indication, I believe Mr.
Cooper's testimony and elsewhere, that when Colonel North's
attention was drawn to the diversion paragraph that he was
surprised or appeared surprised. Do you concur in that assess
ment?
A Yes. Yes.
Q Can you elaborate on it in any way? Can you tell
me from what you drew that conclusion?
A Well, he--I mean, as I recall, his first--he first
Q Let's back up for a second. When he said was this
in my files, was he referring to — was this at the point where
he was first shown the memo or only when his attention was
drawn to it?
said he had written the document and that sort of thing. He
said you found this in my files? We said, yes. And he — I
mean, he was visibly surprised. Meese asked him if this took
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place. He said yes. And you could see him sort of then
recline back in the chair and I think that's about--that ' s
about it in terms of surprise. He was visibly surprised that
Q Can you parse it out at all? Could you determine
here/hei_was_[ surprised that the memo he was looking at had a
reference to the diversion in it? Or was he surprised that
you knew about the diversion in general? Maybe I'm getting
a little too specific.
A Well—
Q What I am trying to find out was he surprised that
here is a memo he says he's written, and all of a sudden he
rears up and realizes there is a paragraph in there relating
to the diversion? Was that what surprised him that there was
a paragraph in there relating to the diversion?
A I would say both. He was clearly surprised we
his reference to — this was in my files — indicated that he was
surprised that it was in the memo. I think it's both. I took
it as both anyway. I mean, he never said anything like, I
can't believe you found this. I thought I'd gotten rid of all
of these. He never intimated anything like that.
But something about that memo surprised him? That
was clear?
A Oh, no question. I mean I'm convinced, he had no
82-732 0-88-12
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idea we were going to find anything that concerned the di-
version.
Q And it wasn't the fact that you had the whole memo?
A No. It was the diversion.
Q He was--it was the diversion paragraph that was
in there?
A That's correct.
Q This then was — looking at the notes-general conver-
sation, after the diversion was broached, about how much was
moved to Nicaragua, that sort of thing; and then the question
of who knew, I guess, and who approved, who approved the
diversion was broached?
A Yes.
Q Can you relate to me what you recall about how that
was raised and what he said about who knew?
A If I can look at those notes, it might help me
refresh my recollection.
Q Sure .
£ The one thing I remember without looking at the
notes is he said specifically the only three people who could
know are the following, which was Poindexter, himself, and
McFarlane.
Q Yes.
UNCUSSIFifP
A But, let me get to the point of — well, they talked
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Q Let's back up a little bit here. There is a refer-
ence here to, "if President okays something into working
files of," who is speaking here? Can you tell? And what is
that a reference to?
A The reference is to if the President okays a memor-
andum or plan, where does it go. That was what we were try-
ing to determine.
Q I think if you go back up, there is a reference here,
"AG, discuss with RK not with N."
North's answer, not with North in the room, not when North
was present.
Q This was then the discussion of the residuals?
A Yes. North continues here, Poindexter-this is what
the notes mean on 15, Poindexter is the point of contact with
the President. Fortier was involved, too. When he became
principal deputy. Question: Do you know the amount? North
didn't know. Question: Was there any CIA handling of that
money? North: No. Don't think they know underlined. Some
pot? It was discussed with the Israelis to how they could
help generally, and that's North and Rabin. Don't recall
asking them. Thought the Israelis offered.
Q Now we have the line, "if the President okays some-
thing into working files of."
w tmm
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Do you recall what that was a reference to?
A I don't have a specific recollection. From the
looks of the note, it looks like Meese asking if the President
okays something, what happens to it; and--normally I used a
dash to indicate the answer. And the dash, into working
files.
Q And this is as best you can understand the notes,
the Attorney General attempting to determine if there was
a written document indicating the President's approval?
A That's right.
Q And then the next line is again, "AG, if RR approved
it, you'd have it"? Is that more or less the question he was
A Yes.
Q North said yes. Then there is a line, "don't think
it was."
A North did not think it was approved by the President.
Q Look at the next two lines. Would you read those
into the record?
A It says, "other files there. It could be in."
I think what it means is other files it could be in.
Question mark.
Q Was that the Attorney General asking North if there
were *any other files where such an approval might be located?
A Yes. I mean. North had said he didn't discuss it
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with the President. He didn't think the President had approv-
ed it. Meese was saying are there other files it could be in
besides yours that — to verify it didn't go forward.
was to verify that it didn't go forward to Reagan; is that
right?
A Yes.
Q And then there is a trunk indicated — what does that
line say?
A The last line, there is a star that says, OLN will
check.
Q What did that mean?
A He said, — we didn't ask him. North volunteered,
I'll check, I don't think so, that it could be in any other
fiels, but I'll be glad to check. I just wrote that down.
We weren't expecting the report back.
Q Okay. But at least at that point — then it goes on,
Check if Israeli dollars got to Nicaraguans.
A Right.
Q What does that mean
A I don't know what that means.
Q Do you recall who was to check if the Israeli
dollars got to Nicaraguans?
A Well, I don't think it was— from looking at the note
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I don't think it was intended in that way. Because if there
were--I use a star and circle if there is some follow-up or
action item. I think this was a statement of information.
But I don't know who made the statement. It could have been
how would you check to see if Israeli money got to the Nicarag-
uans, but I don't know what that means. I don't recall.
Q The previous entry does have a star next to it '
indicating what you have called an action item?
A Yes.
Q Is that your understanding somebody was to do some--
thing as a result of that?
A Well, he said — he volunteered that he was going to
check.
Q Yes.
A I noted that. I don't think — I mean, I don't think
any of us every followed up with him to determine whether
there was additional paperwork in the system.
Q Did anybody say at that point or at any point to
Colonel North, no, don't go and check?
A No.
Q In other words, you didn't say don't go back to
the files?
A No.
Q And see if there is approval?
A No.
nil.
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Q Okay. And to the best of your knowledge, no one
ever followed up to ask him whether he did, in fact, find an
approval?
A That's correct.
Q Would it be fair to say that at least at that point
in the interview, and by the end of the interview, that was
just left as an open item?
A Yes.
Q Okay. Did Colonel North mention any other files
that such an approval might be located in?
A I don't recall any other files, no, that he thought
it might be located in.
Did he indicate what other files he was going to
check;
A No.
Q I think that's all I have on the notes, Pam.
BY MS. NAUGHTON:
Q Did Colonel North indicate that he had spoken to Mr,
McFirlane that day?
A I don't think he did. No. Although he did not —
let me think for a minute. He did not have his car with him
at the Department and when we were done, he asked me for a
ride to get his keys at the White House and then to pick up
his car. And I was going to do it, and then Meese showed
back up from getting his wife. The interview was done. So
um^fpr
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Meese's secretary drove him first to the White House, where
she waited for him to run in and get keys, which I think he
said his wife had brought an extra set of keys in. I didn't
really pick up where he had lost or misplaced his keys; but —
I don't know if she brought them — if she went — if he picked
them up at the guard's gate or if he went to the office. But
Kathy, Meese's secretary waited for him and then drove him
over to pick up his car which he said was parked on the street
around K Street; and then she left from there. At some point
he may have had a conversation — North may have had a conversa-
tion with her and said, you know, I was over at McFarlane's
and my car is over there, would you mind dropping me off,
because at some point, it sticks in my mind, that his car
was near McFarlane's office.
Q This is Cathie Appleyard?_
A Yes.
Q Is that a common spelling?
UNCIASSIREO
A Yes. With a c and i-e, though for the Cathie.
Q After Colonel North left, what did you all discuss?
I assume--
A Well, the number one item was the confirmation of
the — of a diversion as it's come to be known, of a use of the
proceeds of the Iranian arms shipments to fund the contras.
There was a recognition of the need to find out
329
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activity. There was discussion--! believe that night, but it
may well have been the next morning, of trying to determine
what--if this happened, and if it was an authorized activity,
what the legal ramifications could be.
MR. McGOUGH: You said if it was an authorized or
an unauthorized?
THE WITNESS: I said an authorized, but--I mean,
we were looking at, I guess, the first question was--if the
President authorized this, what is the — what are the legal
implications. We were obviously--there was a clear prospect
that it had been unauthorized as well, I mean unauthorized by
the President.
BY MS. NAUGHTON:
Q Excuse me. Did Colonel North say whether or not
A I don't think he did.
ONCLASSIFIEO
A The implication was both of his supervisors knew
about it. He said the only specifically — the only people who
could know were Poindexter and McFarlane. McFarlane, as I
recall — he said McFarlane found out about it in May of 1986;
and so that— I don't think it was specifically said did Poin-
dexter authorize this plan; but his — it was clear that his
later if Secord knew, and he said yes.
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HN8»$SPi|T 120 Q And also Mr. Hakim knew? Right? A I don't know if he knew or not. I haven't followed the hearings that closely. Q No. I am asking you what Colonel North said? A I don't think he metioned Hakim as knowing. Q Did he mention that it was Nir's idea? A My recollection is that he did. But I couldn't point out to you exactly the section of the notes that deal with that. But I think he did. Q So he indicates that there were at least two other ( peole outside of the U.S. Government? A That's right. And he said that Nir may be — I think it's Nir, the Israeli he named may be the only one in the Israeli government who knew, if he had handled the transaction himself. That is Nir. And he described the transaction. As I recall, again without looking at the notes, that he said he called Calero, told him to open up three accounts, got three account numbers, and he gave the account numbers to Nir who put money in the accounts. And my recollection of the Tom Green call /meeting on Monday, that the import of that was that North had told us about how the money changed hands was not correct, that it had changed hands in a different way. I don't recall specifically how, but I know you have someone's notes on that. Q When Colonel North left, was there a discussion as SLK-27 1 2 3 4 5 CO oo t)mssR?ST 121 to what to do with the information that you had learned? A On the--well, there was--I recall one on the diver- sion yes. And the Attorney General said he wanted to talk to the President about this and I don't know if it was Sunday night or Monday morning, we met him again Monday morning at 7:30. And it--out of those two meetings, it was clear he wanted to talk to the Vice President, the President, Don Regan, and Poindexter. I think he talked to McFarlane about this, too, because he met with him briefly Monday morning. Q Did he indicate — A Just to give this some context, at this point we knew that this was a big deal and the question--! mean North had said this layer of my supervisors know. Meese's immedi- ate concern was does the President know about this? Was this authorized by the President? And if he didn't, you know, this was clearly the kind of policy call that he thought that the President, if it happened, that the President should have known about. So that was the immediate shift, and trying to determine if the President knew about it and if it had gone forward to him. So that's what he set out the next day to do, talk to Poindexter, Regan, et cetera. Q On Sunday, did Mr. Meese indicate what he discussed with Mr. Casey the evening before, Saturday evening at Casey's home? A I just don't recall any — I don't have a recollection UTOSSfiWT 122 SLK-281 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 of any report about what he talked to Casey about. North had specifically excluded the prospect that anyone at the CIA knew about the use of money from the Iran shipment to fund the contras, and he had specifically said, and used the word "could." The only ones in the U.S. Government who could know about the use of those monies for the contras were Poindexter, McFarlane, and himself. Q But the Attorney General speaks to Mr. Casey prior to the North interview? A That's right. Q But after the diversion memo was found? A That's right. Q My question to you is did Mr. Meese indicate what he spoke to Mr. Casey about? A I don't recall him mentioning that at the time. He may have, but I just don't remember it. Q Did he mention the visit of Mr. Furmark to Mr. Casey indicating that investors in the Iran arms sale were about to file suit? A Did Meese mention that? Q Yes. A I don't know. I know North — Meese asked North if there were any other problems, bombshells, that wasn't the word he used but that was the import of the question, clearly understood.. One of them mentioned by North was that there were llHWSSlflB MlWHr 123 SLK-29 ., 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Ljuj cr: '' 2r^ 21 ^^°. 22 23 24 95 investors that were getting antsy about not having their money and feeling that there could be problems there. But that's the only thing I recall about that. I don't think I heard about the Furmark materials until maybe Wednesday. Because Casey sent them over to Meese--some Furmark memos with a letter from Casey which — and I think they are dated the 25th, which was Tuesday. I think I may have seen that Wednesday morning. But I don't have any recollection of those before then. Q On Monday, did the Attorney General ask anyone to do any further interviews? In other words, he was going to go to the White House to see the Vice President and other people about this. Did he task anybody else with doing any other interviews? A I don't remember him doing that. He certainly did not task me to do that, but Cooper— I don't know if Cooper was doing anything or not on the other front. He may have still been in contact with the CIA on — I know that he was doing things with the CIA general counsel for sometime. I just don't know. Q And was it discussed with the Attorney General whether or not someone should go along with him when he spoke to Mr. Poindexter and the others? A I don't think so. I don't recall any such discussion I don't think — I don't think there was one. 334 wMsm 124 SLK-301 2 3 4 5 6 7 6 9 10 11 12 13 14 15 16 17 1 « f n=:^ 19 CO 21 ■>-~i 22 9«; By the way, were you present when the Attorney General spoke to Secretary Weinberger? A I don't recall being present, but it's possible that I was. This is on the telephone? Q Yes. A I don't remember. Being there or not being there. Q Did the Attorney General discuss with you what Secretary Weinberger told him. A I don't think so. I mean, all I — and I can't place this in time, but Meese's comments were that Cap doesn't know --Cap doesn't really have many of the details on this, some- thing to that effect. Q Now once the Attorney General returned from ;±he White House, did he tell you what happened? I gather he returned sometime around noon or so? On the 24th? A Let me see if I can remember from looking at--yes. Well, it indicates in my notes. Exhibit 2 here, on the 24th, that we had lunch from 12:45 to 1:30. Meese, Reynolds, Cooper Cribb, and Richardson. But I have, in parentheses, check, with an exclamation point. That may mean I either got the time, the person — or the number of people wrong. But he had a — I know he had — well, there is a notation here, 1:40, V.P. I know he had a NSPG meeting at 2:00. This would indicate he talked to the Vice President at 1:40. I tend to — I don't have a note to this effect, but I tend to recall that he saw UmSflWT 125 SLK-31 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 L.^. IB 19 •esc 20 c-:> 21 22 23 24 25 CO --I know he saw McFarlane around 10:00 in his office and I thought that was over at the White House to see Regan and the President late morning. But he may not — that may have just been Regan and Poindexter. I don't recall anything out of that lunch meeting at 12:45 that day. He may have--I mean, at that point he might have said well, I'll see the Vice President then and I will see the President again at 4:30, something like that. It may still have been fluid. Q Did he tell you at the meeting with the President in the morning that he had told him about the diversion? A To this — I'm still not sure when — which--when he talked to the President that day. I know he did at the end of the day. But I don't recall him — I just don't recall any lunch conversation on that day. Sorry to say. He may have, but he may not have. Q But, I mean, this was the big issue. Did the Presi- dent approve it or not? A Yes. I just don't remember it now. He may have come in and said well, the President doesn't remember this. But I just don't remember now. I mean it was clear by the end of the day, it may have been at lunchtime that the Presi- didn't think he had approved it or that he had never heard of it and Regan had never heard of it and that was confirmed later in the day. But I don't know. I can't say when that UIWSfflEff ET 126 SLK-32 ^^ 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 So " ST 22 23 24 25 conversation occurred. It was obviously the big topic and it was obviously covered at lunch, but I just don't know the content of the conversation. Q Now-- A If I can just — I do know that when he came back at the end of the day Monday, we knew that this had not been authorized by the President for a certainty. Q If I can go back, in the morning, to the meeting with McFarlane? A Yes. Q Were you present at that? A No. To your knowledge was anyone present other than the Attorney General and Mr. McFarlane? A I don't know. Cooper might have been, but I don't — it might have been just Meese and McFarlane. I'm not certain Q Do you know why you were not present? A I mean I was--I had not been in the first McFarlane interview, so I didn't expect to be. I was the most junior and least — to be blunt, least important member of the team. So it didn't surprise me not to be there. Q I am not asking you if you were surprised. I am asking you if you know if there is a reason why you or anyone else wasn't there? A Oh, no. No, I don't. I mean, I know of no reason 337 yirassfflfpT 127 9 10 11 12 13 14 15 16 a^ 17 eg ^« why I was excluded if that's the question. Q Was there an expression on the Attorney General's part prior to that meeting that he wished to speak to Mr. McFarlane, the Vice President, Poindexter, and Regan alone? A I don't think so, no. Q Was there any discussion of whether or not he was going to take notes of these discussions? A No. I don't recall any. Q Now I take it that you know — A Vou know, we might at lunch, we might have talked about — at some point either that morning or the night before Meese told Cooper to find out when the Boland Amendment was passed, and that sort of thing. It may be that there was a preliminary discussion along those lines at lunch that day. But that would be a reasonable guess on what — I know that was covered Monday at some point. Q Other than the early morning meeting with the Attorney General and the lunch meeting, what were you doing Monday? A Well, we — 1 suspect that we probably had our formal 8:10 staff meeting, our 8:30 staff meeting. I could look at his schedule and tell you for sure, but if you have that--but we normally then spend the 9:00 to 9:30 or so timeframe with our schedulers and that sort of thing. That may have been done. I just don't remember. I might have been seeing that leu^EiET 128 copy of the documents from the NSC was made, something along those lines. I just don't recall. Q Did you feel confident as of Monday that you had seen all the documents you needed to see? A Well, we had been through almost all of what North had provided to us. We had not been through some files marked 11986. We had been through all 1985 material and all the 1986 material marked White House memoranda or miscel- laneous. So — I mean, I felt confident — I knew that we had been through everything that had been provided to us. I couldn't say that I thought every document that existed in the government on the subject I had looked at, but — at this point, — I mean the weekend tasking was get the facts, there's a 2:00 o'clock meeting on Monday. At this point, by Monday, we had learned the facts and we hadn't pursued every detail, but at this point, there is a major — I mean obviously what happen- ed in 1985 was much less significant than the diversion; and the attention was focused very — immediately on the diversion. Cooper was looking into some of the legal questions. I'm not sure what I was doing. I might have just been in my office working or looking through some of these memoranda, but the focus of things shifted immediately to Meese working at a level with the President and the Vice President, Regan, Poin- dexter, to figure out what happened and what this factual revelation meant. So, I mean--my intimate activity in terms SLK-35 CO CO uKt^ssraiET of looking at documents and all that stuff had become a secon- dary thing. I mean this was clear— I mean, there was a very clear consensus Sunday night, reiterated explicitly Monday morning. We've got to find out what happened, was this authorized, and make this public; and so that is the track that was moving very quickly and those other activities which seemed much more important 24 hours earlier were much less important at this point. Q Why was it so important for it to become public so quickly before you had all of the facts? A Well, Monday was spent getting all the facts. That is— I mean the important facts. Did the President know about this? Who else knew about it? Those were the crucial things at this point. It's pretty obvious that this was a major development, that the Reagan initiative had already been the subject of three weeks of very serious public debate and the Administration was dealing with a serious foreign policy problem. I mean, this is from my personal perspective. There was also— I mean it was obvious that this development compound ed that dramatically and— I mean Meese was conscious through- out, that is throughout Sunday night when he and I had a brief conversation and Monday morning when this conversation occur- red that with this kind of development, all information had to be gathered quickly and made public quickly, because this —I mean, this is obviously— was going to create a problem 340 lIMniKCIOcn 130 SLK-36 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 ■ « ' 18 '"'— 19 ^— t; 21 ^■p 22 — ^ 23 24 for the Administration and could only be compounded if it were not made public. By public, I mean Congress to be notified, because there had been--the three weeks preceding, the debate had centered upon the nation — the failure to notify Congress on the arms initiative; and I think that was the bas- ic reasoning. Q But my question is why go public so quickly? In- other words, a decision was made to go public prior to, for instance, informing the FBI what had occurred. The infor- mation to go--the decision to go public and the going public of the information was prior to interviewing many of the key players in the Iran arms transaction. So my question was what is it that triggered Tuesday noon as zero hour for when it was going to go public? A Well, I mean — I would see no basis for informing the FBI, for example, as an entity. And all the key players had been interviewed. I mean North had been interviewed. We didn't track down Secord and Hakim or any of that sort of thing. The President was interested, Meese was interested in what do Administration officials know about this. Q Was Mr. Casey asked if he knew about the diversion? A I don't think — well, I don't know. The Attorney General has said that he did not raise that with Casey before the interview with North. But that it was discussed with Casey, as I understand it, Tuesday morning at Casey's home. 341 K-37 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 £^^ 16 CO 19 ^i*' 21 —- ^ 22 23 24 25 OffiEASStFlir 131 because apparently Regan had said something to Casey about it. So — but it's obvious that with this kind of a devel- opment, that this was going to cause a major political problem for the Administration; and--I mean Meese, in the interview with North, said we don't want anything that can even look like a coverup. We want to get to the facts and get them to the President and this was before knowing about the — getting Meese--getting North to confirm the contra diversion. So I think the interest was in — as this bombshell was learned, it was to be made public as soon as possible, because it would have been--if this had been made public by someone other than the President, that would have added to the problem. So there was a concern of leaks as well? A I mean I didn't — I know Cooper has tagged it as a concern of leaks. I didn't view it that way. I guess — I mean — I was concerned personally. I mean Meese was commit- ted to getting this public as soon as possible. He didn't say I want to get this public because x, y, and z. In con- versations with Cooper, he said, you know, this thing could leak out, et cetera. I said the key is to get the President to make this public. And the President has — I mean, through- out this, certainly since this time, has wanted to make — get the accurate inforroation and msJte it known. This was a major operation, a major policy initiative that blended 342 um^iiisi^ 132 SLK-38 1 2 3 4 5 6 7 e 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 two very important and controversial policies together and the President didn't know about it. So it's obviously-- I mean in hindsight and it was clear to us at the time that unless this was made public immediately, that it would create even more problems for the Administration. Q As you said, if someone else would have--were to have mentioned it, if it were to come out by some other means other than the Administration? A Right. Q Okay. A I mean, with rumors — rumors at CIA about this and that. Q Monday afternoon, the meeting vith Green, I tate it you were not involved in the A That's right. Q Did you receive a report about it? A As I recall, yes. Q And in that report, — when you received the report about it, were you in the presence of the other tecim members or was this-- A I think I was. I think Meese, Reynolds, and Cooper and there may have been others present, too. I think I have a note on that, but I'm just not sure. Q Was it discussed then that Albert Hakim was — let me back up. Mr. Cooper's notes indicate that they were told •" UNCLASSIFIED 343 imiMibT ■esse 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 9S that Albert Hakim was the guy who originated the idea of the diversion, according to Mr. Green. Do you recall that being state to the group? A No. I mean, it may have been. I don't recall it. Q Do you remember Mr. Hakim's name coming up? A No. I don't recall it. Q Now on Tuesday morning, you were tasked to go to the White House to look at documents? A Well, I rode into work with Meese Tuesday morning. I live very near his house. So once in awhile, I just hop a ride with him. That coincidentally happened to be one such day. So I rode with him from his house. He stopped by Casey's house. We went to the Department. He met briefly with Poin- dexter. He met--we then grabbed Cooper. In fact, Meese called Cooper from the car, and Cooper was still at home, and said be in my office by X time. Q When you stopped at Mr. Casey's house, did you take part in that meeting or did you stay in the car? A No. I sat in the car. Q And do you recall how long the meeting was? A My notes reflect, I think— well, in Exhibit 2, my notes seem to indicate five minutes. 6:40 to 6:45 a.m. Might have been a little longer. Actually it seemed a little longer in hindsight, but five to ten minues, 1 would say. While he was in there, there was a call placed to 344 uttsA^n' 134 SLK-40 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 to the car froni Don Regan--from the White House operator. I told him he was in Casey's house. I think he called him in there or we ran in with the message to Keese who called Regan. I can't recall which. Q Was Regan calling for Meese or for Casey? A For Meese. Q Why is is that you didn't go into Casey's house with Mr. Meese? A No particular reason. I wasn't asked to and I normally wouldn't sit in on a meeting between Meese and Casey. Q Did the person who placed the call for Mr. Regan indicate what he wanted? A No. I think it was a White House — the White House operator and I tend to recall that Meese 's driver ran in-- ran up to Casey's door and said that Regan was trying to reach him. As opposed to our directing the operator to Casey's residence. Q Did Regan place the call then to Casey's residence? A I don't — I mean I think based on my recollection that the driver went and told Meese that Meese placed a call to Regan from Casey's residence. Q But— A They did talk, when they were in there. Q They did not talk in the car? A Right. Because when he came back, I said did you yiLASSIFIED 345 SLK-41 1 2 3 4 5 6 7 uiffia»ie8ET 135 L.^ '^^^ 22 23 24 get Regan, as I recall; and he said yes. Q Did he say what Mr. Regan wanted? A No. I don't think he did. I don't recall that. But he — Meese then placed a call to Poindexter who was not in his office. He was in his car. So he reached him in his car and he asked him if he could meet— Poindexter if he could meet Meese at the Department. Q When is it that you discovered that Regan had told Casey about the diversion? A Oh, at sometime substantially later. It could have been in the last month. It was a statement to that effect. I'm not sure that he did, I should say. I just— my recollec- tion is that someone said that Regan had told Casey about it. Meese may have said that. I'm not sure. Q When the Attorney General got back into the car after visiting with Casey, did he tell you what he talked about? A No. I don't think he did. And we were— Meese 's driver and a FBI agent were in the front seat, so he — I mean he didn't get into any details. I mean I would not have ex- pected him to give me an update on the diversion of funds in front of those— in front of his driver and the agent. Q Were you present when Admiral Poindexter met with Meese at DOJ? A No. They met one on one and I was outside the door. 346 SLK-42 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 E»UJ 17 Lju. 18 19 20 21 22 23 24 UTOSSSfflffiET 136 Q Do you know how long that lasted? A Well, my note here-again in Exhibit 2, indicates it was about 15 minutes. Ten, fifteen probably. Did you have any indication that Poindexter would be asked to resign? A I'm pretty sure that I knew after the meeting. I don't know that I knew before. I just don't recall. But I grabbed Cooper probably while the meeting was underway and I think Meese pulled Cooper in and we talked briefly. I think he said Poindexter is going to be resigning this morning, we're going over to the White House. That's just my recollection. It's not crystal clear. Q Was there any discussion of Colonel North's being resigned or fired? A I don't think there was there at the Department. Q Did you discuss that with the Attorney General or did he discuss that with anyone in your presence? A Well, we went — the next meeting was at the White House with Regan and Wallison and Thompson and then Meese, Cooper, and myself. I mean at some point before the press conference--and I don't know at what point, this might have been with Meese and Regan out of the room, I understood that Poindexter would be requesting reassignment to the Navy. Q Okay. A 1 may have learned about Colonel North when I saw 347 SLK-4 3 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 CO 19 C<3 ^20 S3f 21 22 23 24 «r UllSOTBF' 137 a draft of the President's statement. Q Do you know who wrote that? A Yes. Let me think here a second. Well, after the Regan-Meese meeting broke up, which was about 9:00 o'clock when Regan and Meese went down to the Oval Office, Cooper and Thompson and Wallison were tasked to write a statement. I was tasked to go down to Thompson's office and look at docu- ments. I cim not sure who penned it, but between the three of them, they wrote one. Because I joined up with them later in the morning up in Wallison 's office. They were going over a draft. Q There seems to be much discussion primarily amongst Colonel North and Admiral Poindexter as to why Poindexter was allowed to ask for reassignment and why North was summarily discharged from the NSC, can you shed any light on that decision making process? A I was not present when that was discussed with Meese and I don't know that Meese was a part of that. It's my impression, purely an impression,, that — I mean, that was a — just something that Don Regan and or his deputies had done. I mean, I don't even--I got the impression, and I believe that it may have been that day, I'm not sure when, that North was not informed about this. And it may have just been an over- sight on the part of Regan and his deputies. I don't recall any specific discussions saying, all right, we are going to wisaps&ET 138 SLK-44 1 2 3 4 5 6 7 8 9 10 11 12 13 End SLK 14 15 16 17 18 19 20 21 22 23 24 25 do this to North and this to Poindexter. Although there may have been out of my presence. Q You were tasked with finding out whether or not any of these documents got to the President. A Right. Q By some other system or some other manner? A Yes. Q What did you do to try to find that out? A I went down to Thompson's office, told him that that is what I wanted to do. He--and I described the nature of the search and the need to search all the systems that would pro- duce documents to the President. He said okay, we'll do that. He came back at some point with a lady, his executive secre- tary, and she brought me some documents that were responsive. OllASSIHED 349 6:00 wmmw 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 BY MS. NAUGHTON: Q Do you remember what her name is? A No, she looked to be about 50, with brown curly or wavey hair, sort of short, but I don't remember her name. She had some documents which I looked through, and I said, "How have you searched' and she told me the six or seven terms she used. There were things like Iran arms shipment, Nicaragua, contras, that sort of thing, and I questioned her about it, saying, "Well, would this kind of document show up on this search, and does your computer scan all that kind of thing, and satisfied myself that this would have been found, and she said, "We will make sure it is," which she did. And I don't think she brought me a second load of documents, I think Thompson came in and said, "That is all we found." In that group of documents, I recall one document that was relevant, which was minutes of an NSPG, I think, a meeting where third country assistance to the Nicaraguan resistance was discussed, and the Secretary of State specifically was talking about it. There was no mention in that meeting, in those minutes, at least of the use of the arms shipment proceeds to fund the contras. Q Do you recall when that meeting was? ! anus snxpiueiit pi.v./1-ccus ONMSSIFIED 350 bap-2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 tf' *) 17 JL « f or ^^ So ^' ^ 20 y ^ 21 23 24 25 «H8«SS|}iaF 140 A No, I did then, but I don't. We turned those notes over, though. I tend to think it was sometime in 1986, May or sometime in the spring, early summer of 1986, but that is just the vaguest recollection. In the meantime, I looked through Thompson/ Poindexter file, saw the findings of 6 January, saw a document of -- at the time I looked quickly. There was nothing that the President had signed other than the findings. I think a copy of the second findings was in there, but I am not crystal clear. But there were a number of documents which said, "Shred after reading," that sort of thing, which were scenarios of events involving arms shipment, hostages. I took one page of notes on these and one of the interests. Things that I recall was that they expected Khomeini to be dead on a certain date, and that — which was, I thought, was very interesting. There were one or two other things. I took a note in addition to the 17 January findings in the 6 January finding, which was the words, "third party," and one or two things like that. When I finished that, I went up to Wallison's office and reported to them that there was nothing else there that I saw, looked over the statement. I made those comments to Cooper. He said, "That is already being fixed." I don't remember what 351 bap-3 UTOBlSBfltST 141 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 ia La»Jl9 £20 CO 21 ^» 22 it was, but it wasn't much, and then I think we were told that we knew that NSC was going to meet with the President, I think, in the Oval Office, and then the Congressional Leadership was going to be briefed, and we were told that we would be -- Tore Dawson, Regan's aide, you and Cooper will be in the Congressional briefing. And the next event that 1 recall was being in the Congressional briefing waiting around outside the cabinet room while they all showed up. Q If we can go back to the documents, given by Paul Thompson's executive secretary/ were any of those System 4 documents? A Don't recall. I did not focus on that. I might have seen a System 4 up there, and it did not register at all. Q When you did see the finding of January 6, was it in with other documents, or did he retrieve it separately? A It was in the pile. Let me think here. He showed it to me, but I tend to think that he showed it to me and said here is this, and then put it down, and I went ahead and went through other things. I think it was in a folder by itself. I think it was the original. Q Do you remember seeing ink? A Blue ink. I think it was signed in blue ink by the President, and it was — I don't know if the — what I 352 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 ijJLj 20 £b=21 0O22 3^3 ^24 z:r::5 25 142 can't remember is if the editing was done on the original or on a copy. I don't remember that. Now, as of Tuesday morning, was it clear that this was going to be the Presidential statement and the Attorney General having press conference? A Yes. Q So the format was already established by then. A Well, over the course of the meetings there it may have come out of the 8 o'clock meeting or we might have met Meese and Regan back in the office at 10:00 but I am not sure, but at some point over the course of the meeting I knew before the Congressional Briefing, I knew that we were going from that to a press conference; that Meese would take the main lead in addressing the press. Q The Attorney General mentioned in his presence that the matter would be referred to the Crijninal Division. A That is probably correct, I don't. I haven't looked at the transcript recently. I did look at my notes of the Congressional Briefing where he indicated that this would be reviewed for any criminal liability. Q When was that decision made? A I don't know. I think that is my first recollection of it, of hearing that. There had been discussions Monday. There had been discussions after the North interview Sunday night or Monday morning, that this presented new legal 353 mroiWF 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 ,.. 18 LO-J 19 C/O 21 :::;:> 24 25 problems, which I guess is an obvious enough conclusion, and Cooper had undertaken to detennine and the example I specifically remember is when the Boland Amendment was in place, and if so, what are the implications of that for this transaction. And I recall that there were, I believe there was a conversation about that on Monday -- yes, Boland was passed on X date. I don't recall any discussion of — although there may have been, Meese may have said something like see what other laws are implicated by this, but I am not crystal clear on when that was. I know Cooper would probably be clearer because he was tasked to do it. But, I know that on Tuesday, when we got back, it was formally kicked into a criminal investigation. Q Bringing Mr. Weld and Mr. Trott into this? A Yes, sir, and he met with Webster and I think they talked about getting -- I guess the first meeting was with Weld, Trott and et al. He net with Webster about having a team of agents put together that could work very quickly on this. Q Do you know whether this meeting was at the Attorney General's impetus or Mr. Webster? A Yes, I think he asked. I believe he asked Webster to come over and meet him. I could be wrong on that. This was a matter that they had discussed before. 354 MftSMBET 144 Q Were you present when they discussed it on Friday' A No. Q Was anyone to your knowledge? A I don't think so. Q Were you present when they discussed it on Tuesday? A No, not on Tuesday, not that I recall. Well, let me take that back. I don't think I was, no. It is possible. I don't know if I got an entry that indicates that. This 25 November entry in Exhibit 2 indicates that I was present in the meeting with Webster — 2:05 Meese, Webster, Arnold Burns, Cooper, Richardson, Qribb, Reynolds, and Trott joined the meeting at 2:20. So I was present, 1 guess, when that — when they decided it is time to go criminal. I don't recall that. Q The meeting the next day, the large meeting when representatives of the FBI were present and so forth, was Mr. Webster present, do you recall? A I don't think he was. Q But are — A I think Floyd Clark was present. Q But you recall him there on the 25 meeting at around 2:00? 'lUSSIFlEO Has there a discussion then of securing the 355 WfflW 145 documents at the White House on the 25th? A Yes, on Tuesday the 25th, Meese instructed Arnold Burns to call Wallison and the reason is any time there is communication between the Justice Department and the White House on pending cases or such as it is between the Deputy's office and the Counsel's office, to call Wallison and make sure that they secured North's documents, Poindexter's documents. Q Do you know when that was actually done? A I know it had been done at the end of the day. My recollection is that there was a meeting again at the end of the day, and where we were reviewing, I had been tasked to draft a piece, written document, request a document description of all these documents should be located and held for the Hireau, and we were going over that at the late afternoon meeting and — MR. MCGOUGH: Would this be the 6:40 meeting? THE WITNESS: Yes. I think Meese asked — Meese said something — Meese said, "Have the documents been secured," and Arnie said, "I haven't got through to Wallison, or something like that, and he left the room and did so. I recall he came back and said Wallison has already done that, something along those lines, which makes me think it was taken care of on Tuesday afternoon. 356 wmm^ 146 BY MS. NAUGHTON: Q The letter that you drafted, do you know when that was sent? A Well, it wasn't a letter. It was plain white paper, a paragraph, describing the field of documents, and I don't know when it was sent. I don't. Q Who was in charge of sending it? A I think it was to be an Arnold Burns to Peter Wallison meroo, but I do not know if it was in fact sent. I know that a group of letters were sent. I guess this was — Wednesday was the day before Thanksgiving. I think the letters went Friday to Cabinet officials asking for documents on the subject, and I don't know if Wallison instead got one of those letters to make the formal request or if there was a nemo. I just don't recall. Q Who was in charge of drafting the cabinet letters? A I don't know. Q When was the possibility of appointing independent counsel first discussed? A I don't know that. Q Well, at some point it was discussed in your presence, I take it. A It sure was. f\ w.e it- Hiern<;<5*>(l with Trott and Weld when they were 357 yWGft^BfflET 147 brought in at 2 o'clock? A It may have been. I just don't recall the first time it was discussed. I mean, it was fairly soon after this issue, after it became a criminal investigation, because one of the first — we have had a number, a lot of experience with these matters, and having independent counsel investigations, and one of the early things on the table was whether this first triggering mechanism had been met. And I mean I recall discussions of whether North was a covered person or Poindexter, and that sort of thing. I am not sure when they began. Not before Tuesday afternoon, I am sure of that. Q There was some discussion along those lines, was there not? A Yes, sir. Q About appointing instead a "special prosecutor," that would be a part of the Department of Justice, but sort of on a separate track. Do you recall that discussion? A Well, I did not until you mentioned it. I vaguely recall that. There was considerable discussion about whether there was enough information or criminal conduct and/or criminal liability to proceed with an independent counsel, and there — I remember specifically thinking that we weren't quite there even when the decision 358 nny^m 1 was made — Weld, I recall, had problems although he was — 2 he had produced a draft that cited every statute in the 3 code practically. There was a lot of concern that if we 4 followed the law, the independent counsel statute, we were 5 not in independent counsel territory based on facts, 6 and the laws that we knew, and someone, I think, surfaced 7 this as a concept that we will because of the political 8 climate, what you might want to do is look at appointing 9 someone to operate independently, but not within the 10 independent counsel's statute. 11 I don't think that was — my recollection it was 12 very much a passing suggestion and not an option one or 13 option two. 14 Q Do you know what the Attorney General's position 15 was Wednesday, the 26th? •J6 A I couldn't — 17 Q Regarding the counsel? 18 A Well, I think his — I don't know as of Wednesday, 19 the 2eth. His view had been, as I recall, he had expressed 20 this view, this was — this probably was going to end up with 21 an independent counsel, but we based on discussions he got 22 out of it in terms of doing interviews and that sort of 23 thing, after we turned it over to the criminal side, and 24 it was in the mode of Trott and Weld coming up and saying, lira rtn*- «->t»es 1 »uc . 4-hAe» farts." .'.-•■ 'I c ...V. » «- 359 iimssm^ 149 independent counsel, and that being the sort of terms of discussion, and I don't think this other business was a serious option. But the conversation kept coining back to well, we don't really have enough to proceed under the independent counsel statute yet. Then Weld came in the first or second day with a rash of legal theories that how one could have criminally built ranging from conspiracy to violation of civil law like the Boland Amendment was a crime to all kinds of fraud prospect based upon not knowing who did what with these amounts of money and where they went or the intermediate theory of this was government money, and it is fraud against the government. So they had that kind of range of things. No facts to back them up yet. Q Once Mr. Cribb got into it, and when he returned fr cat his trip and came back on Monday, and took part in sevaral of these meetings, did you know whether or not he took notes? A I don't know whether — I did not know whether he did or not. Q Is it typical for him to take notes in such a meeting? A His typical approach was to take action notes so he would have a list, and if he were to do something, he 360 bap- 12 imifflFipT 150 CO 1 would take a note down, but he did not take, as a rule, 2 meeting notes or that sort of thing. 3 Q Was there anyone assigned or anyone who 4 generally took such notes that you have described as meeting 5 notes in the Monday morning staff meetings, the preliminary 6 meetings or 8:30 meeting? 7 A Yes, I always took notes in the 8:30 meeting. 8 I have a spiral notebook that eventually — I regularly 9 listed it in spiral notebooks. 10 As an aside, these notebooks I bought with my own 11 money so that my attempt was to create a personal record 12 that I could take home and that would be of historical 13 and personal use so it would not be a document subject 14 to FOIA. So it was more of a — I took action items 15 on occasion in there, or occasionally on a yellow sheet, but 1g I was the principal note-taker. iy Now, Meese occasionally took action notes out 13 of the 8:30 meeting. I have since learned, though, I lig dlto't really pay attention. Occasionally people write I 2Q down things they are supposed to do. Terry Eastland, 21 who is Director for Public Affairs and Randy Levine, who 22 is in the Deputy's office, he took more systematic notes. 23 I really wasn't aware of that. I don't think anyone at 24 the 8:10 meetings — there are only five of us in there -- 25 takes notes. For a time I used to take 8:10 notes in my 361 IftltW^fipT 151 binder with the 8:30 meeting notes, but I stopped doing that. Q And regarding Mr. Bolton, these staff meetings and these meetings that he attended on the 20th and possibly the 21st, do you recall whether or not he took notes? A He does take notes. There are not comprehensive notes like I try to take. He takes action notes, that he has a small pad that will fit into the inside of the coat pocket, and if Meese asks him to do something or check up on something, he will jot it down. Q Now, we are going to go through just a few more documents. MS. NAUGHTON: If you could mark this one next in order, please. (The document referred to was marked for identification as Exhibit JR-10.) BY MS. NAUGHTON: Q Now, Exhibit 10 is a document taken from the spiral notebook, dated 29 October 1986. Are those your notes or the Attorney General' A They are my notes. Q This is the discussion of the requests by the House Judiciary Committee members regarding independent counsel to be appointed. If you could review that and tell '' ONMSSIFIES 362 bap-14 UmSSIffitT 152 ::sr23 rae what the discussion was. A Okay. Q Can you describe to us what that discussion was about? A Okay. It is not clear who is speaking for the first entry because you can — I would have written someone's name up here with a colon and made a point here, then went on to these, so someone — Q If I recall, for the record we have a redacted copy. A This is a redacted copy. Whoever has — the redaction has also included the name of the speaker for the first entry on the note. But it refers to a Conyers letter, and independent counsel request. Our response — this is me interpreting my notes — our response was to ask for more specific information, if any. Then we would review that information. Then speaking to Terry Eastland — I would guess. Well, I don't know this — speaking to Terry Eastland, the statement put out a press advisory that there is not "a preliminary investigation" to set the record straight, public record. That is, the letter that had been received had not triggered a preliminary investigation, but instead we had asked for more specific information. It may just 363 WUU^t&Br 153 be based on a press report, which occasionally would happen. Then Weld says, "Let's just get the word out, to make clear what our position is." And Eastland says, "We will be sure to make sure certain large media know." Then Cooper says, "There is lots in OLC on triggering the Independent Counsel Act and the Neutrality Act." That entry means that OLC has a lot of institutional learning, legal analysis and opinions on both questions, triggering the Independent Counsel Statute and the neutrality and/or Neutrality Act. Q Then there is a portion that is redacted. A Yes. Can you tell us what that was? No, I have no idea. Then, the subject is apparently — Then — We do have this on the sane subject, the Q A Q A Q portion . A Right, it says, "Provide some briefs to Griffin Bell on Neutrality Act." I guess that is to Griffen Bell when he was Attorney General, but I don't know. Then it says "others which are non-public are available." Then there it says, "AG," with an arrow to Cooper, "Do a FOIA analysis. OLC will work with Criminial Division llNrJIlSSIFlEO 364 9 10 11 12 13 14 15 16 ^^ 17 iJUi 18 19 So 20 21 22 23 24 Iral^lwclcir 154 Q What did that mean, do FOIA analysis? A I think that referred to — well, I am not sure, but my guess from looking at this is to determine if OLC opinions are subject to FOIA. I don't know why one would have that. But this here mentions non-'public opinions available. He probably said would these be discoverable to the public under FOIA. I guess they could have been implicating a number of things. Either a FOIA request had been received or this line, they were saying how would we draw the line under FOIA for whether to make this public or not. That may have driven the decision about what documents to release. Q All right. Going through the rest of these in no particular order, we could mark this Exhibit 11. (The document referred to was marked for identification as Exhibit JR-11.) BY MS. NAUGHTON: Q Exhibit 11 appears to be actually a little drawing of a balance of scales. One says arms to Iran; the other scale says intelligence to Iraq. It is on white stationery. Do you know who drew that? A The handwriting looks like the Attorney General's. I don't know if he drew this or not, but it looks like his handwritino. 365 155 Q At any rate you did not. A No, I did not. Q This could be marked Exhibit 12, please. (The document referred to, was marked for identification as Exhibit JR-12.) THE WITNESS: This was found in his office, by the way. BY MS. NAUGHTON: Q Exhibit 11 was found — A In the Attorney General's office, or files, I should say. I am not sure whether it was in his office or in his files. Q Showing you exhibit 12, then, which again is on White House stationery, it says at the top, "any other facts." Is that your handwriting or the Attorney General's? A The Attorney General's. Q Were you present when there was a conversation to this effect? A I don't think so. This entry says, "any other facts." That is Number one. Number two, problems, "broke no laws, defensive weapons." It is possible that that conversation occurred the morning of the 25th and/or at some point when I was either present or not. It is not dated, and I know that this was, again, found in the immediate offices of the Attorney General, either in 366 .ap-18 UNtUSSHpT 156 there was nothing else to indicate what it was. Q Were you involved in the document production to the Select Committees? A Yes. Q And I take it then if this document was produced to the Select Committees, it was thought to be relevant to the investigation. In other words, this is not about some drug case or something, is it? A Well, we didn't know. When we found this, when we looked at this, it said defensive weapons, broke no law. We weren't sure what it meant, and it wasn't in any particular file. As I recall, it was in a pile of miscellaneous material, so I am not sure. I wanted to be sure to turn it over, emything that was a question mark over. Q The next exhibit to be marked is 13, please. (The document referred to was marked for identification as Exhibit JR-13.) BY MS. NAUGHTON: Q Directing your attention to Exhibit 13, then says "Nicaraguan Angle. "Contras funding. WNCIASSIFIED 367 VNftAMfi&T 157 Q Is this your handwriting? A Yes. Q Do you recall when that document was generated? A It was generated, as I recall, over the course of the weekend, probably Sunday night, because it was clearly after the North interview. Because the information contained in entry 1 is all post North interview. Q Okay. A It might have been Monday, but this may have been one of the things I was doing Monday. I would bet it was Sunday night, though. Q Were these notes done in a meeting, do you know? A I don't think so. I think they — I might have been in a meeting, and I was writing this down on my own, but this did not represent the discussions in a meeting. This was representing my thinking and my organizing. Q Did you show these notes to anybody? A I don't think I showed them to anyone. MS. NAUGHTON: If we could mark the next one as Exhibit 14. (The document referred to was marked for identification as Exhibit JR-14.) BY MS. NAUGHTON: Q And Exhibit 14, then, is a document with a heading, UNCLASSIFIEO 368 bap-20 i/massw 158 1 "Wby? There is." Could you tell us when this document 2 was generated? 3 A This is my handwriting. I wrote it, I believe, 4 very late Saturday night or in the wee hours of Sunday 5 morning. 6 Q Did you write this at home? 7 A Yes. 8 Q And could you tell us what the discussion is, g I guess, you are having with yourself? 10 A Yes, that is right. I was writing down •J1 possible reasons for some of the things that were going on. 12 One, more extensive relationship with Iran, which I guess 13 I am restructuring, but I think that simply means to the 14 greater strategic opening rationale, Iran strategically 15 located, all that sort of thing. 1Q Number two, more extensive relationship with 17 Israel. I think that refers to the principal reason for 13 tlM initiative is trying to be cooperative and build our ig bridges with Israel. As you can see, no weight assigned 20 to any of these theories, and they are marked, "theories." 21 Three, relationship with Nicaragua. Four, 22 cover own tracks, and this — do you want me to read the -- 23 Q yes. 24 A The "cover own tracks" — drew strict limits 25 vis-a-vis arms, but McFarland present. North, others. ^mw 159 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 question mark, went beyond that, unauthorized agents in September/November transactions. Q These, I assume, are the 1985 transactions? A Right. And this again, I showed these to no one. These were me sitting down trying to think up what could have led to all of this and the prospect was that the President had, might have said no arms, but we will explore the initiative and McFarlane and others went beyond that and beyond arms in the things, and therefore the September/ November transactions might have been authorized by someone, but not the President, and that they were trying now to cover their own tracks on the September/November shipment in terms of authorization. Number five, again, says, "Cover own tracks." Arms deal with G, probably meaning Ghorbanifar, a loser, not really with effective present prowess faction. That would have — I guess 1 was thinking there that it was d*|»cribed as stratigic initiative and that it was described as strategic initiative and that sort of thing, but it really turned out to be loser of the deal, not what they expect, and now there was concern on that end. Q You have a reference at page 4, September 1986 minutes. What is that a reference to? A I wonder if that is a reference to the chronology. Q It refers to minutes. 370 wmim IfiO A September -- what would have been in September 1986? I don't know what that refers to. Q I gather you did have your documents at home with you. Were you looking through them as you were writing. A Gentlemen, I was flipping through the documents. Entry four has a present footnote — McFarlane and Shultz. Q Number six says? A Six, "Reasons for secrecy, Soviet anxiety." Again, it refers to minutes, September 1986 minutes. Q Okay. And finally, seven. A Seven says,- "Involvement of Vice President, Regan, Casey, Poindexter, Tompson, CIA personnel^^^^H Q What does that refer to? A I don't know other than what it says. This may have just been we should check the involvement of these foUcs. MS. NAUGHTON: Mark this Exhibit Number 15, please. (The document referred to was marked for identification as Exhibit JR-15.) THE WITNESS: I should just say if I had known these were going to be preserved for posterity's sake, I would have written more extensive explanations and not have put down — I don't know if I would have put do*m all 371 bap- 2 3 IflKK^SE^ 161 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 these sort of theories, but anyway — Q I am mostly concerned with identifying and — A I would like to know myself. Okay, Exhibit 15, this is my handwriting. I think that the bottom half of this where I have got numbers 1 through 4 are questions that I wanted to ask North, and which were jotted down during the North interview when other people were question- ing him. I have checked, I have got a check mark of things which I believe represent that I asked that question. Q So this document was generated, then, sometime Saturday? A Sunday afternoon. Q Afternoon. A These are contemporaneous notes taken during the interview. You need to ask North this. And, it looks to me like the top half was some existing document, s(^ne existing notes. The bottom half I had flipped open as writing down during the interview. Q The reference ^°^^^^^^^^^^H ^o y°^ what that is a reference to? A What comes to mind is I believe that there was Q Provided to the Iranians? 372 TcPwwiHBt 162 A Well, either they or the Iraqis. Probably the Iranians. Very fuzzy recollection of something like that. But I think it was! The entry above is intelligence exchange, so I think that is probably what it refers to. Q Then there is a reference to Ghorbanifar money. A Then present other lost money. Q Then there is a parenthetical, Casey. Apparently Weinberger, Shultz, Vice President. A There is another entry here that says Nicaragua angle withan arrow, and it lists North, Poindexter, McFarlane, Regan, Thompson, RR. And to the right of that is Secord. I have checked off in front of the names North, Poindexter, McFarlane and Secord. I believe that indicates those are people that we Knew about the Nicaraguan angle. Besides Regan, Thompson, anA R.R., I have got a bracket with a question mark. That means we don't know what these three know. Then there is a third — second or third list depending on how you are counting, says, "Casey, Weinberger, Shultz, VP,"with a bracket on the side. We don't know what they know either. Q Was Paul Thompson ever asked if he knew of the diversion? h T ''on * ^ ♦•ViinV ^o ».,fl^. 373 iiNeumi^ 163 1 Q Was there any discussion as to whether to ask him 2 or not to ask him? 3 A It was by time — I think that it had well 4 moved away from finding out everyone at that level who would 5 know. I don't think there was that discussion. 6 Q Then there was a reference to see McMahon, 7 Secord, Cave. Are those people that should be interviewed? 8 A That's how I would interpret it now, but I don't 9 know . 10 Q Were these notes taken again on your own or 11 at a meeting. 12 A These were my random notes of — I expect what 13 I did, probably have written down — this is my guess in 14 trying to reconstruct these — the top part of these were — 15 and I got a line drawn, top third, I think are things 16 I thought we might want to cover with North. I am 17 guMsing. 13 When we covered certain individuals, we checked 19 them off. I checked them off. The bottom third I know 20 was covered — I did during the North interview. The 21 middle third I am not sure about. 22 Q Okay. We could mark these two next in order, 16 23 and 17. 24 (The documents referred to were marked for tc I identification as Exhibits 16 and 17. ^ 374 bap- 2 6 IIIKlA%N<tE|ET 164 BY MS. NAUGHTON: Q Exhibit 16 appears to be a document, not dated. Three areas vulnerable, apparently. A Yes. Q Abbreviation. Could you tell us when that document was generated? A No, I can't. Q Are these your notes? A These are my notes, both 16 and 17. Sixteen, three areas of vulnerability, and I have only listed one, which are the TOWs, 508 TOWs and the Hawks. And the problem listed no reporting, AEC a violation, or if acquiesced, Hughes, Ryan, no finding. This is probably Sunday evening. Could be earlier, but I think it is probably then, sometime over the course of the weekend. Q Okay. MR. MCGOUGH: To which transaction, if any, does that relate? THE WITNESS: The number one? The TOWs and — MR. MCGOUGH: TOW 508. THE WITNESS: September/November 1985, those two transactions. BY MS. NAUGHTON: Q Okay, and the next exhibit, 17, which simply says, "Tell R.R. , re Nicaraguan angle," right? UNCLASSIFIED 375 ap-27 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 1W8t*K!fffiF 165 A Yes. That is — would have this after the North interview. This would have been — it is an obvious thing to tell the President about it. Q Well, do you recall first why you wrote that? Firstly, did you write that? A Yes, this is ray writing. As I recall, I had a legal pad and I flipped over and wrote down Exhibit 16, three areas of vulnerability and started on one. I don't know why I didn't finish with the other two, and flipped the page again, and tell R.R. re Nicaraguan angle. When this was found, I think when I produced this stuff, they were the first ten pages of a legal tablet, and so Z assume pages were, as can be obvious in reviewing them now, were scrap paper rambling thoughts, that sort of thing. This is not a redacted document. There is nothing else on the Exhibit 17. The original of all of these, by the way, are in tt0 hands of the independent counsel. Q Do you have any of your original documents in the hands of the Wedtech either independent counsel or held at the White House for the Wedtech independent counsel? A Are any of them being held? Q Yes. A Not of my documents. Only Meese's spiral notebooks. UNCLASSIFIED 376 WkfSSffB^ 166 Q So all of yours are with the Iran Contra independent counsel? A Yes, except with the one category of the staff meetings notebooks, I don't -- I am not sure where they are. I think we have got them in our control room, but I am not sure. Q Now, were these exhibits, 16 and 17, taken at meetings or again are they just your own thoughts? A I don't recall. These may well have — if I were guessing, I would say they were probably taken during team meetings where we sat down and sort of were reviewing the bidding where we stood thus far. Q And ~ A They are probably my thoughts. MS. NAUGHTON: If I could have these marked -- these exhibits marked Exhibits 18, 19 and 20. (The documents referred to were marked for identification as Exhibits JR-18, 19 and 20, respectively.) BY MS. NAUGHTON: Q Okay, I direct your attention to Exhibit 18, which is at the top marked "508 TOWs." Is that your handwriting? A Yes. UNMSSIFIEO Q Do you recall when you generated that document: A No. 377 jap-29 WEUSSBift;' Co 20 ■S"*^ 21 Si^ 22 ^^ 23 24 167 Q Was it sometime during the weekend? A It might have been. I would tend to think, well it was certainly after the North interview because of the Nicaraguan angle mentioned, and it may have been — this may be why Exhibit 16 only has one area because here it breaks out number 2 is 508 TOWs and, legal problems with those number two is Hawk shipment, and, three, legal problems with those. Three is Nicaraguan angle. So that makes me thing it might have been Monday. Could even have been Tuesday. I would guess it was probably Monday. Q Then four is criminal prosecutions. A Yes. Q And five says, "Secord." A Yes. Q Do you remember why you are listing those, what do you have in mind when you put these things together? A Well, I don't know. I didn't know Secord until the North interview. That helps date it as well. It is clearly sometime after that. Criminal prosecutions was not on the table until late Monday or Tuesday, as if that refers to the criminal li2Q5ility of the individuals involved in this. May be that, I don't know. I think it would not refer to armed shipment Ko^aiiee T ♦■ViinV T ur^>^^H K;«^ro wrS*-*-on ^ho«a t-Viat- w;*V. T 378 bap- 30 yifciBSBffiET 168 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 think it tends to refer to criminal liability of the individuals involved in this. Q And Exhibit 19, which is entitled, A That is my handwriting. Q Now is this pursuant to a meeting or is it pursuant to just — A I think this looks like just a scrap note of mine because one of the entries shows the lunch time on Saturday. Q What the reference ^°^^^^^^^|^H ^°' you recall? A No. Q And Exhibit Number 20? A Twenty is also my handwriting. Miscellaneous notes. Q If I could look through them. A Sure. Q There is a reference to a date on the bottom, 21 November. Do you recall when all of these notes were taken on the 21st of November. A No, I don't recall that. Q Okay. Let's start at the beginning, then. A What makes me wonder, on the bottom left corner it shows the Friday interview of McFarlane. That was the 21st, though. Right? UNCLASSIFIED 379 •VQv-wBi^ 169 A Maybe it was, I don't recall, though. I'm sorry. Q The top says Sporkin. A Right. Q Upper right-hand corner an A.G. notes telephone logs. Is that him instructing you to keep notes and logs of weekend activities? A I don't know. It might be, but I don't know. Q Is there anything else that it could be a reference to? A Unless it is an instruction for me to check notes or telephone logs, but I think that I would have listed that differently. 1 think that is probably what it refers to. Q And then it says, "Monday." A JRB. Q That is Mr. Bolton? A Yes . It says A.G. — Re law. What does that mean? on hill. IINOLASSIRED A I don't know what that means. Q Then A.G. call Poindexter, Casey, Regan, Sporkin. What is that a discussion of? A Well, it is in the margin from that it says, Sunday talk shows." I think this was to make sure that no 380 wmm 170 one from the Administration went on the Sunday talk shows to talk about the Iranian initiative. Q Do you know if those calls were made to — A I think Meese called — well, I think he called Regan. Q For him to call these people not to appear on the talk shows? A Yes. I don't think he called all of them. I think it was just Regan. In fact, the Regan entry may refer to the Sunday talk shows, and the other two just to making — that he wanted to make those calls, but I don't know. This would, the next entry says, "Office coverage for the OAG," which is our office on Saturday. One with the AOG, one if the front office that refers to our secretaries. Q Moving down here, if you could dicipher these tbsse notes for me. Okay, right here. UNCLASSIFIED A This is a circle in the bottom. It says, "Bolton debriefing on Senate Intelligence hearings present. Bolton was present, and he gave a debriefing on the hearings during the meeting at 2:25 on that day. It also says with Casey, present, CIA something. Don't know what that says. It says, "Armacost, Armitage." wmstKer 171 1 Then, it says, "dash. House present, will get 2 Hyde debriefed." 3 As I recall, he was not permitted to attend 4 the House Intelligence Committee meeting, and said he was 5 going to try to get debriefed by Congressman Hyde. 6 Q Do you know if that occurred? Did he later 7 report? 8 A I don't recall whether that happened or not. 9 Q If we could mark that exhibit 21, please. 10 (The document referred to was marked for 11 identification as Exhibit JR-21.) 12 (Recess.) 13 BY MS. NAUGHTON: 14 Q Turning to Exhibit 21, are these your notes? 15 A Yes. 16 Q Were they made on the 25th of November? 17 A Yes. 18 Q If I could look at it for a moment. 19 A Sure . 20 These were taken by me when I was going through 21 documents and in Thompson's office. 22 Q Okay, my question is the third entry says, "Ollie 23 memo in mid file. Ollie brought over last night." 24 Do you recall what that is? 25 A No. over i.asi;^ nignt. UNCLASSIFIED 382 p-34 KWHSSflflF 172 Q Are you telling — A I think the phrase, "Ollie brought over last nigh," means that was a notation on the memo. Like Ollie brought this over last night. Q Do you know which memo that refers to? A No. Q Then the next reference is to JP memo to RR, the 17th finding. Then, on the second. A One of the things I found interesting that go get Weir out revolutionary guard had to storm the building and demand release of one hostage. It showed that they aren't clearly in the pocket, but it is things like that I thought were — Q Now on the second page, there is -- A I corrected myself. It wasn't Khomeini dies, it is Khomeini steps down on the 11 February. That was in the plan. Q On the second page it says Casey told 14 December note. Do you recall what that is? A Vaguely I do because there is a note in there. It said something like Casey was told on 14th of September — didn't say what he was told, didn't say. It said — I can't remember precisely, but it said something about Casey being informed about something on the 14th of September. 383 UlffiBIWifflE :t 173 Q Was this a handwritten note? A I think, yes, it was. Q Do you recognize whether it was Colonel North's handwriting? A No. Q Did you ask anybody about that reference? A No. Q Did you get a copy of that note? A No. Q Did you get a copy of any of the documents that you were shown by Mr. Thompson? A No. Q Have this marked Exhibit Number 22. (The document referred to was marked for identification as Exhibit JR-22.) BY MS. NAUGHTON: Q And Exhibit 22 is, again, 25 November, 6:40 p.m., press update guidance. I want to ask you on the second page ~ A This is my handwriting, by the way. Q Thank you. On the second page it says Weld, Secord, recently criminal target. A Yes. Q Do you know was that the first time this was ICUSSIREO 384 bap-36 HNSUSSii&T 174 brought to your attention. A Yes. Q Secord had been a criminal target before. A Yes. I think he referred to, as I remember, an investigation in late 1979. Q Okay, did he say what about? A Well, it remains in my mind something to do with Wilson, but I don't remember if he mentioned it at this point or if I heard that later. Q Okay. If we could mark this Exhibit 23. (The document referred to was marked for identification as Exhibit JR-23.) BY MS. NAUGHTON: Q The front page of Exhibit 23 says please note that the attached document was typed prior to March 15, 1986. A Yes, sir. Q And the second page is a memo to the Attorney General from MAM. Who is that? A That is Marlee, M-A-R-L-E-E, Melvin. She was confidential assistant personal secretary to the Attorney General and this ceime out of her files. She is now a special assistant. This came out of her files that she maintained when she was confidential assistant, and so page 1 indicating that it was typed prior to March 15, that 385 oveu^fls^T 175 is the date she changed jobs. So we deduce it was typed while she was back in the -- Q Excuse me. When did she change jobs? A It was in March of 1986. Probably early March, but we — Q And if you could please just read that short memo she typed. A Says EM, it is on Office of Attorney General stationery. "EM, Oliver North's office said you agree with Admiral Poindexter to see North today? Do you want to meet with him after judicial selection at White House and delay your departure for home? Or what? Meeting should last 15 to 20 minutes. Contact Fawn at 395-3345, MAM, 12:30 p.m." Then there is a handwritten notation which is Meese's handwriting says, "4:55, A with a circle, Roosevelt Room, 4:50." I would interpret that to mean Meese met him aihead of judicial selection 5 o'clock in the Roosevelt room. Q Do you recall when this judicial selection was? A No, they are normally on Thursdays. Q Did you ask Ms. Melvin about this note? A I did. She didn't have any — it was not with anything that would assist in determining what it meant or what it was or when it happened. Q All right, if we could mark this as Exhibit 386 bap-38 1 2 3 |)N8ttSaBBkT 176 Number 24. (The document referred to was marked for identification as Exhibit JR-24.) BY MS. NAUGHTON: Q Exhibit 24 is a document on the front of which says, "This document cannot be dated nor can subject matter to which it was related be recalled." Did you draft this cover? A I don't think so. I think that was done by , lawyers in the Office of Legal Counsel. But it might have been done by one of the lawyers on our staff. Q Do you know whether it refers to the statement "nor can the subject matter to which it was related be recalled," does that — who doesn't recall it? In other words, who was queried? Do you know who was queried as to whether they could recall it? A I don't know. I might have asked the A.G. if this meant anything to him, but — Q The second page, for the record, is on American University stationery. A Right, apparently Office of the President. Q Right. And the notes regard Adnan Khashoggi, Robert Shaheen, S-H-A-H-E-E-N, and McFarlane has not seen the memo of 20 March. When you asked the Attorney General about this 387 bap «N£M$KlflilT
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did he recall this document?
A I don't know that I did. I probably did, but
because I tried to go through the unidentified notes
with him. I don't think he recalled it.
Q Do you know whose handwriting that is?
A No.
A I know it was found in our office, I think. I
don't think it was in any particular file.
Q Do you know on what occasion that was at the
American University.
A No.
Q Other than what is an apparent from the page,
do you know anything about that?
A No, no idea.
Q Okay. If we could mark that, please. Exhibit 25.
(The dociment referred to was marked for
identification as Exhibit JR-25.)
BY MS. NAUGHTON:
Q The cover of Exhibit 25 says, "This document, cannot
be dated nor can subject matter to which it is related be
recalled."
The second page of the document is on White House
stationery.
A Right.
UNCLASSIFIED
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Q Could you read the note?
A Yes, it looks like the Attorney General's
writing, and it says maybe we should contract the job out
to the Israelis.
Q And do you know when that document was generated?
A No, I don't. We had one other — the drawing of
the scales -- it is in the Roosevelt Room. The pads on
the tables are plain, so this would not be in the
Roosevelt Room meeting. I don't know what they do in the
Sit Room where they have the NSC meetings. It may be they
use these pads down there, and this was written and showed
to someone during a meeting.
A I believe I did, and I don't think he recalled
Q And the next — finally, believe it or not.
Exhibit Number 26.
(The docioment referred to was marked for
identification as Exhibit JR-26.)
BY MS. NAUGHTON:
Q Okay, 26. Is that all in your handwriting?
A Yes.
Q Now, the top reference is Casey, Poindexter and
brackets, and says, "misstatements to Congress/."
A It means Senators. S-E-N-S.
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Q Do you know when that document was generated?
A No. Although it is at the bottom, it is dated
24th of November with a lunch time. Then 1:30 to the
White House VP at 1:40.
My best estimate would be it had been done that
Monday the 24th. I don't know. I don't recall that.
Q The reference to Poindexter and Casey misstatements
a meeting?
A I don't recall.
Q Do you know when you wrote it down, what you
were thinking?
A No. I gather, trying to think back on Monday,
information learned over the weekend have been different
from information provided Friday, and that probably is
what it refers to, but I don't recall.
Q Was there a discussion at any time during the
Tuesday; that there was a possible violation of law in
that Casey or Poindexter may have made misstatements to
Congress.
A No. There was no discussion about possible
violations of the law from that being done.
Q Was it discussed regardless of whether there was
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1 A I don't recall any discussion about there
2 having been misstatements to Congress, no.
3 Q You can't recall what made you write that note?
4 A No.
5 Q Did you read the transcript of the Attorney
6 General's deposition?
7 A No. I read the first paragraph of the deposition
8 with you, I guess. That is the only one I know of.
9 Q Yes. Do you know anybody who read it other
10 than the Attorney General?
11 A No. Steve Matthews may have read it, but I
12 don't know for a fact. I provided it to him. He is
13 keeping custody of some of those things.
14 Q Okay, those are all my questions. Thank you
16 EXAMINATION ON BEHALF OF SENATE SELECT COMMITTEE
17 BY MR. MCGOUGH:
13 Q Do you ever recall seeing Colonel North in the
19 Attorney General's office or visiting the Attorney General
20 at his office.
21 A No, but the one meeting that apparently occurred
22 which was January 6, 1986, was before I was Chief of Staff,
23 so I would not — I would not know — be in a position to
24 know that and to keep track of that. After March -- really
25 effective February of 1986, but in officially first part
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of March of 1986 I was Chief of Staff, and I would have
known.
Q There were references very early on in the
depostion t
and one that you believe
you saw. Was it only one that you can recall seeing
or might there be more than one?
A There might have been more than one, but I only
recall one.
Q Can you put any kind of time frame on it? I
believe they were talking about the fall of 1985 as being
possible — do you recollect it being in the fall of 1985?
A No.
Q Could it have been in 1986?
A It could have been 1986.
I took on new duties in March of 1986, as I
said, but I kept the^^fon portfolio for several months
until it just became — I just decided to put another
lawyer on it, and get them trained up. I think it was
certainly months before that occurred, and even still it
was possible, as I recall. I tend to recall this as a
rush sort of rush job, and on various sensitive or very
urgent things.
They would come, might come to my office, I
would handle it personally.
Q Do you ever recall being contacted by anyone
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1 outside the Department of Justice with a request that
a^^^^^^^^^^^^^B be
3 A Yes, well I was not, but I recall one incident
^ where such a call was made and Bill Casey called the
5 Attorney General about having expedited
6 and I spent Friday night until 1:00 in the morning with
7 Webster's guy, and then met Meese at the White House
8 Saturday morning early. He was at a breakfast or something
9 and got that down.
10 Q Do you recall did that relate at all to either
11 Iran or Nicaragua?
12 A I just don't recall. I don't remember what
13 the subject was. I could try to go and pick it out, but
14 I don't recall the subject.
15 Q Do you recall any time frame on it..
16 A Well, I know I still lived in McLean, but that
17 doesn't help us much. That means it was before January of
18 this year. So, no, I don't really.
19 Q Do you remember where the Attorney General was
20 the next morning.
21 A He was at the White House Hostage — a coffee and
22 doughnuts for a group that —
24 you fix it?
9K A Yes. sir. If it aooeared on a schedule, it mav
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183
well appear on a schedule, but it was probably some group
like Junior Statesmen or he does a lot with them. There
are several youth groups, kids coming in, interns and
that sort of thing. It may have been one of those.
I tend to think it was the Westpoint cadets maybe
in 1986, be my guess. I might be able to track that down.
Q If you could track that down.
A I will make a note.
Q Other than that incident where Mr. Casey called
to expedite ^^^^^^^^^^^^^^^P can you any
other learning or any other cases where someone attempted
to expedite^^^^^l
A Well, by calling Meese or me, no. There were
a number of instances where client agencies were upset or
the FBI was concerned with the time lag and^^^^is a good
example, RPA.
Q Let's narrow it down. Do you recall learning
of any calls from NSC regarding I
A I don't think — I don't recall any. I don't
recall it out entirely, but I don't recall any. I did
not receive it, I are sure.
At one point in talking about the fact findings
weekend, you referred to the Iranian initiative or the
subject of your investigation as I have it written down in
ouo«-ps. the tooic of soecial interests f^lmost a<? if that
394
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were a code or designation that was used as a term of art.
Does that term have any significance?
A No.
Q It was just the way you said it.
A Iran initiative was the term of art.
Q You mentioned that the only person you believe
you mentioned or you spoke to at the Iranian initiative--
I'm sorry, of the diversion, during the course of the
fact finding weekend or up in the press conference was
Ken Cribb. Was the Attorney General aware that you had
A Yes, Cribb joined us as ny recollection. He
joined us at this 7:30 meeting on that Monday the 24th.
Q Was aware of you told Ken Cribb, that you were
going to tell Cribb.
A I don't think so.
Q Did that create any problems from the Attorney
General's standpoint?
A No, I may have told — I may have told Meese I
will brief Ken tomorrow morning. But I don't know. Ken
and Meese were very close. Ken was my superior, and there
was — that was not a surprise to Meese. He may have known
it in advance, but it would not have. It was anticipated
that Cribb would join the deliberations and the activities
the next day.
iJNClASSIfe
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185
Q Did the Attorney General ever chastize either you
or anybody in the group of four for what he perceived to
be dissemination of the information about the diversion?
A No. Not that I ever heard.
Q Did it ever come to your attention that there
was-- did it ever come to your attention there was a
possibility that a member of the press had the story of the
diversion on the night of Monday, November 24th?
A No.
Q To your knowledge, did any member of the press
A No.
Q That evening?
A No.
Q To your knowledge, when William French Smith
was Attorney General, was there a formal listed procedure
for findings being submitted to the Department of Justice?
A Well, I can answer based on the conversation
I had about a week ago with Mary Lawton, as I understand it
the rule with Smith was that they would come to the
Justice for clearance, but there was a continual back and
forth to be sure that they did.
Q To your knowledge, did Attorney General Meese
attempt to reassert that rule when he became Attorney
General?
!iNn!A.^.<vinFn
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A To my knowledge, he did not. In fact, when I
handled findings, which I think I mentioned, I handled
two of them as Chief of Staff, it was not something he
expected, and just recently a couple of weeks ago whenever
I talked to Mary, he said, "You find what the findings
process and what the department's role is because--" So I am
pretty sure he did not assert any formal role in that,
although he sits on the National Security Council, and
there has been a continual desire on his part to increase
the formal participation of the department in national
security matters, so that their legal ramifications are
considered more routinely.
That is normally resisted by NSC. I don't know
that that — generically the answer is, yes, but I don't
think it ever rooted itself out in terms of saying I want
the finding to come here first.
Q At one point you referred to the Presidential,
President's alleged prerogative in the field of foreign
affairs as being, I think you put it, arrangement of last
resort in the context of the Iranian initiative and
finding, or lack thereof. Was it discussed in those terms
by the Attorney General and your group?
A No, it was put in, I should clarify, because it
was put in terms of what authority, what legal authority
<~;(n ho rolipd uDon for the President to undertake this
397
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187
activity, and there is explicit authority given certain
processes in certain other statutes.
Q The Arms Export Control Act and National
Security Act being two of them?
A Yes, sir, covert action, for example, Hughes-
Ryan you have to have a finding, but there is a school of
thought depending on which activities you are talking
about, that certain statutes, notwithstanding the President
has inherent constitutional authority to undertake
certain activities on behalf of the United States in the
conduct of foreign policy or other areas, and that if a
statute had been violated, just one thing that is discussed -
well, there is the President's inherent authority obviously,
if you have that up against a statute, it is difficult, more
difficult arrangements to make.
For example, there is a school of thought which
I happen to adhere to that the War Powers Act is an infringe-
ment of Presidential authority and the notations and that
sort of thing, so that is what I am referring to. There
are things that the executive branch out of comity had
tried to activate its practices to because they think
they are good ideas or that sort of thing and because it
is the law, but if push came to shove, there may be certain
circumstances where in spite of a statute, the President's
constitutional authority might be a basis for action.
398
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188
Q Was that theory discussed in connection with
specifically Iranian initiative?
A It might have been mentioned, but the principal
area of focus was where these laws complied with and, if
not, we have got a violation of the law.
Q To the best of your recollection, did anyone
say it wouldn't be a violation because the President has
inherent authority to sell arms outside?
A No, I was thinking this more in terms of if
authorized by the President, what would the legal posture
be, and this being one possibility, but it didn't
receive great attention because it wasn't-- we found out
immediately it wasn't authorized, and I think it might
have been in the conversation with Cooper as opposed to
Meese.
Q I have to ask this question. Was Oliver North
shredding documents while you were present in the NSC?
A No, he was not.
Q Can you state —
yilASSlFlf
A He was not. He was in the room with us almost
the whole time, excuse me.
Q Can you state with some certainty that North was
399
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or did not shred any docuraents anywhere in your vicinity
during the time that you were there?
A Yes, I aun certain. I am certain he did not.
Q Do you know where the shredder was located?
A Yes.
Q How far away from you?
A May I even draw you a map?
Q Yes.
A It won't be to scale.
Q Why don't we put an exhibit sticker on it and
mark this as the next exhibit.
(The document referred to was marked for
identification as Exhibit JR-27.)
THE WITNESS: Okay.
BY MR. MCGOUGH:
Q Just describe what we have got with Exhibit 27.
A There was a small suite of offices. Brad and I
were sitting at the conference table in Ollie North's
office. Ollie North was behind his desk. Outside his
office was another small office, two secretarial desks, a
few cabinets. Then there was a small room off to the
corner, with more file cabinets and the shredder, coffee
machine up on top of the table cabinets. Then in the main
office where the second door to the hall and Xerox machine,
and then over in this corner where I have aot wash marks
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190
is a stairway up to the second floor.
We are probably not more than a dozen feet or
20 feet from the shredder. Ollie did not leave the office
more than a couple of times that I recall, a couple of
three times. I went with hira to the coffee machine.
He wanted to —
Q Did you go with him purposely to keep an eye
on him or just was it a coincidence that you went with him.
A The principal reason for my end of things was
I didn't want him to serve me coffee. I just soon as do
it myself. So I walk over there with him.
Q You didn't feel a need to keep an eye on him
when he walked out of the office.
A No, no, not particularly. But, anyway, we went
back in there. I saw the shredder. I saw the shredder
again when we were looking at some of the files. The
bag was half or three-quarters full, but Brad, Ollie was
in the office with us most of the time.
Brad, from where he was sitting, could see the
entrance to a little room with the shredder. It is a very
small room. He would have known if Ollie had taken anything
in there. Both of us would have heard the shredder if it
had been turned on because we have a shredder, and I shred
my documents — I shred some of my things myself. But
I am very familiar with what the shredder sounds like.
401
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191
He has the same kind of shredder we have in our
office.
Q Could you tell whether this shredder was
operatable at that time?
A I couldn't tell. There was shredded paper in
the bag. It is a see-through bag underneath. I don't
know whether it was working or not. That shredder did
not go on while we were in the office. I am practically
certain of that. The only conceivable thing is if he
had slipped out with one sheet of paper and it had a two-
second blast, I think we would have heard that as well.
I don't think he had any intention of shredding
documents while we were there, to tell you the truth.
Q Have you discussed your recollection with
Mr. Reynolds:
And?
UNCUSSIFIEO
A He is even more firm in his view than I am. He
says he was sitting in a position where he could see Ollie
enter the room. There is no way he took a document in there
to shred it. I think he was confused. He was doing it on
another occasion.
Q Exhibit 8 — I can show you my copy -- this is
going to be a quick question. One of the notes that you
passed to Brad Reynolds* you underlined the word "should,"
402
bap- 5 4
HNSUSSmr
192
in the sentence, "If anything should turn up to be missing...'
Was there any reason for emphasizing the "should?"
A I think the way I would look at that now, I didn't
think anything was, so I emphasized if anything should be
missing, this would be better. I had no basis to think
anything was missing. I guess that is why I underlined
it to let him know just on the outside chance that we had
had a problem or misplaced something.
Q Am I correct in my time sequence that Colonel
North arrived for the first time as you were leaving
for lunch?
A Yes.
Q Did you keep a log or a list of the documents
that you wanted to have copied? I noticed partially
Exhibit 8 appears to be a partial log.
A It was not for that purpose. I did not keep a
log for the purpose of copying. I had intended after we
got back to the department to put together a log of
documents actually copied, but I didn't get to that in
the series of other events.
Q In the course of the fact-finding weekend, up to
the time of the Attorney General's press conference, do you
recall any discussion of the possibility that documents
would be destroyed or altered:
mumB
403
mmm
193
Q When you were briefed by Mr. Reynolds on Mr.
Green's conversation with him, did Mr. Reynolds tell you
that Mr. Green did not want or suggested that no disclosures
be made of the initiative because of potential danger to
people involved?
A Well, I recall Brad mentioning that he did not
think that the initiative should be disclosed.
Q Now, he, being. Green?
A He, being Green, because there were things we
didn't know or something like that, but I don't recall
it being linked to individual safety, but you know.
Brad took notes of that discussion and was present, so
ray recollection is not very much firmer on that.
Q Did Mr. Reynolds indicate to you that he had
indicated to Mr. Green in any way that the initiative or
the diversion would not be disclosed until they got back
to Mr. Green?
A I don't recall that it may not. I don't recall
at all.
Q You said you were briefed, I believe, in the
conversation at the same time as the Attorney General?
A I think that's right, yes.
Q At the point when — can you put a time frame on
that when you were briefed on that conversation?
A It was either at lunch or at that meeting at the
404
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end of the day, the 8 o'clock meeting on Monday, because
Meese was out of the office late morning until lunch time,
and then he was gone again from 1:40 until 4:30 or 5:00.
I recall that. Whenever that meeting occurred, the
next session we were together I think he debriefed.
Q At the time Mr. Reynolds made or briefed the
Attorney General on the meeting with Green, did the
Attorney General indicate any inclination either to
release it-publicly, the information publicly, or not to
release it publicly?
don't release this information." What was the Attorney
General's reaction to that?
A I don't recall any specific reaction.
/
reached at that point to release the next day?
A I don't think — I mean one had not been
communicated to roe. I expected that there would be an
announcement imminently.
Q When did you first realize that the matter was
going to be announced at the time it was?
A Tuesday morning.
Q Did anyone consult or were you present at any
discussions or involved in any discussions of whether to
release it on Tuesday morning or Tuesday afternoon or to
405
iHNtassiHff
195
hold it for a few days?
A At the 8 o'clock meeting with Regan and Meese,
etcetera, they were talking in terms of making it public
that morning.
Q Were you present during that meeting?
A Yes.
Q And can you recall what the course of the
conversation was about the pros and cons of releasing
it that day as opposed to —
A It wasn't that type of discussion. The
discussion that Regan said, as we have talked, "We will
go down and see the President. We will have Poindexter
resign. We will present the President with the following
plan for sequence for events."
"The Congress, at this time, we will have a news
conference where the President will make a statement.
You will then brief the press. We will have a special panel
appointed to look into this," and they through out a
couple of names. It was that kind of thing, and this is
what they were going to go in and talk to the President
about as a plan of action.
I gather that the decision was actually made with
the President at 9 o'clock.
Q Moving to a little later that morning, when you
were assigned or asked to make a determination as to
406
bap-58
WKbTOIIW
196
when a meitio had gone to the President, when there had been
a Presidential approval, how much time did you consume
doing that?
A I wasn't asked to make that determination, but
it was to check the files and make sure that people's
memory that nothing had gone forward to the President
was not contradicted by a document.
For example, you might have seen -- I mean there
are documents in there where Poindexter writes, "brief to
the President orally," and dates it and signs it, and
Meese wanted to make sure that there was neither a formal
signature document or a document like that in the main
files. So it was more of a double-check to be sure we
don't have one of these in there.
Q And how long did you have to do that?
A Probably an hour would be my guess. I got the
clear impression, though, that they were not going public
until he heard back that there was no such document.
Q But you also got the impression, did you not,
that there was some urgency?
A Oh, no question, no question. In fact, I think
I knew the general time sequence by then.
Q The answer to this question is obvious, but did
you make any attempt to contact Colonel North and ask him
if he had followed up on his offer on Sunday to check the
407
enMW
197
1 files.
2 A None.
3 Q Why not?
4 A This was clearly beyond Colonel North at this
5 point. I was asked to check. North knew of no such
6 document when he was asked. We saw none in his files, and
7 I was asked to search the principal filing system.
8 Out of common sense, I wasn't going to call
9 North at this point and ask him if that had been done.
10 Q But he had stated —
11 A Yes, he did say he would check. I don't know
12 if he checked or not.
13 Q The point is no one ever got back to him.
14 A No one ever got back to him and I did the
15 checking Tuesday morning.
1g Q Did you ever tell anyone at the White House,
17 including Colonel Thompson, that Colonel North had said
13 he was going to go back in the files and look for exactly
19 that type of document.
20 A No, I don't think I did.
21 Q We can agree that the type of document that
22 Colonel North said he was going to look for on Sunday
23 afternoon was exactly the type of document you were ^oojc^in^
24 for on Tuesday morning.
25 A Yes. His actually probably was a more narrow
imeni: you were looKing
UNCLASSIFIEB
408
iKKifti^Wir
1 category of Presidential approval. I was looking for not
2 only that, but if it could have even been in a briefing
3 paper that had been given to or orally presented to the
4 President as a information matter.
5 Q I am a little unclear on Exhibit 5. This is
6 the one where somebody is covering their tracks. I was
7 a little unclear as to who they were, who was covering
8 their tracks. This is Exhibit 14.
g Who was covering who's tracks in item Numbers
10 4 and 5?
11 A. Well, I am not clear myself. In four I would
12 guess either McFarlane, North or Shultz. I would probably
13 think the same, McFarlane, North in Number 5.
14 In other words, whoever had been responsible for
15 the initiative, a failed initiative, or for an initiative
16 as in Item 4 that had exceeded their authority, so that is
17 probably the universe of people that I would be contemplating
18 McFarlane, Poindexter, Shultz, North.
19 Q Just one quick look, and I think I am done.
20 BY MS. NAUGHTON:
21 Q Can I ask one question?
22 While Regan and Meese were discussing on Tuesday
23 morning what has turned out to be the Tower panel —
24 A Right.
25 Q — who were the first neunes that were suggested?
UNWSSIflED
409
bap-61
WKMIEifiT
199
A Oy, boy, let me think.
Q Was Ron Brzezinski?
A I think so. I want to say Ann Armstrong, as well,
but I don't know. I know she is on PFIAB Pifabs.
Q At the time, were either Mr. Tower, Senator
Muskie or Mr. Scowcroft suggested?
A I just don't recall. The conversation was
something like, "and will announce the formation of a
special board with people like Brzezinski or Tower or
Armstrong." I don't really recall. The names were not
particularly central at that point. I don't really
know who picked them. I guess the President.
MR. MCGOUGH: That is all I have.
EXAMINATION ON BEHALF OF THE HOUSE SELECT COMMITTEE
BY MR. BUCK:
Q I need to rehash the events of November 22 real
quick. When did you arrive at the NSC, particularly at
North's office?
A I think that was late morning. Let me see if I
have i t .
Q Refer to Exhibit 2.
UNCLASSIFIEC
A You know what is going to be helpful is the list
of — well, yes, when I arrived is different than when I
actually started the document review, because Exhibit 8,
it says 12:05 document starts, so that is when I actually
410
bap-62
HKtftSSitllT
200
sat down and started taking these notes. Also at the top
of Exhibit 8, it says, "arrived approximately 11:30,
Paul WBR to JR to North's office met Bob Earl."
Let me see if this exhibit sheds more light on
it. No, there is no mention of it in Exhibit 2. That
is my best guess there. It was late morning.
Q Let me get this straight. You arrived in
North's office around 11 o'clock?
A No, I think we arrived at the White House around
documents that we wanted. Earl brought them out and we
actually settled down to me taking notes at 12:05.
MS. NAUGHTON: You just said you met Poindexter.
THE WITNESS: I'm sorry, I meant Thompson, thank
you.
BY MR. BUCK:
Q When did you meet North?
A It was as we were leaving for lunch. We had
left the office and it was probably — and he was probably
10 feet away from the door on the way out.
Q I have got you at a lunch at 1:45, so you left
A Yes, I would say, a little later.
Q About an hour and a half of document review
before you went.
UNCLASSinEO
411
Um^llFT
201
A Yes.
Q Were you aware that the shredder, which you have
described in North's office there was not functional?
A No. I don't know whether it was or not.
Q At what point in time did you notice the shredding
machine? Did you notice it in the morning or the
afternoon?
A I don't know. I am sure I saw it after lunch
when North and I went into the — in to make coffee, but
I probably noticed it upon arrival, when Earl was pointing
out the different files and the drawers were ajar.
The shredder was right next to him, so I
probably noticed it then.
Q Were you aware of a second shredding machine
just outside of North's office?
A No.
Q And North was there when you returned from lunch?
A Yes. Earl might have opened it. North might
have been at his desk, but he was definitely in the office.
Q I take it North could have shredded documents while
you were out on lunch.
A Yes.
ONCLASSIFIED
Q Do you know how long a period that was?
A It would have been about an hour and a half,
roughly.
412
bap-64
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202
Q Do you recall seeing North at any time leave
the office that you were in with him, with documents?
A No.
Q And you said he left maybe a few times?
A A couple of times I would think. I know once
to do the coffee. I don't think he ever left with
documents in hand. He was working at his desk, but
there was very little papfer on the desk. He was reading
a newspaper, on the phone. I mean he didn't seem to be
going — he was not going through files or great volumes
of paper.
Q Did Thompson stop by and accompany North anywhere;
A Not that I saw.
Q Did you see anything that would suggest that
North was shredding at any time that you were in his
office?
A No, nothing.
MR. BUCK: I have no more questions.
(Whereupon, at 7:50 p.m., the deposition was
concluded. )
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UNCLASSIFIED
Oliver North's office said you
to see North today?
Do you want to meet with him
after Judicial Selection at the
departure for home? Or what?
Meeting should last 15-20 minutes.
CONTACT: Fawn at 395-3345.
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THE AMERICAN UNIVERSTTY
WASHINCTON DC
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mm. Qp PROCEEDINGS
CONFIDENTIAL
UNITED STATES SENATE
SELECT COMMITTEE ON
SECRET MILITARY ASSISTANCE TO
IRAN AND THE NICARAGUAN OPPOSITION
WCWSS(F(ED
i
DEPOSITION OP ALFONSO ROBELO C
CONFIDBN'^IAL
Partially Declassilied/Releasea cm ^O^** oa
under provisions ol E 12356
by K Johnson, National Security Council
Washington, D. C.
Thursday, April 23, 1987
Ace-Federal R eport ers, Inc.
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UimSSIflED
UNITED STATES SENATE
SELECT COMMITTEE ON
SECRET MILITARY ASSISTANCE TO
IRAN AND THE NICARAGUAN OPPOSITION
DEPOSITION OF ALFONSO ROBELO C.
Washington, D. C.
Thursday, April 23, 1987
Deposition of ALFONSO ROBELO C, called for examination
pursuant to notice of deposition, at the offices of the Senate
Select Conunittee, Hart Senate Office Building, Suite 530, at
10:00 a.m. before JOEL BREITNER, a Notary Public within and
for the District of Columbia, when were present:
RICHARD PARRY, ESQ.
Associate Counsel
United States Senate
Select Committee on
Secret Military Assistance
to Iran and the Nicaraguan
Opposition
901 Hart Senate Office Building
Washington, D. C. 20510
KENNETH R. BUCK, ESQ.
Assistant Minority Counsel
House of Representatives
Select Committee to Investigate
Covert Arms Transactions with
Iran
H-419, The Capitol
Washington, D. C. 20515
ROBERT A. BERMINGHAM, Investigator
House of Representatives Select
Committee
Partially Oeclassitied/Reieased nn t J^W S8
under provisions ol E 12356
by K Johnson. Nanonal Security Council
202-347.3700 ^ Nationwide Coverage
463
mmmi
CONTENTS
WITNESS
Alfonso Robelo
by Mr. Parry
by Mr. Bermingham
by Mr. Parry
by Mr. Buck
by Mr. Parry
EXAMINATION
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ROBELO DEPOSITION NUMBER
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Exhibit 2
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Whereupon,
ALFONSO ROBELO
was called as a witness and, having first been duly sworn,
was examined and testified as follows:
EXAMINATION
BY MR. PARRY:
Q First, Mr. Robelo, I would like to thank you for
coming in today. It has been completely voluntary, there has
been no subpoena, and we appreciate the full cooperation that
you have given the House and Senate Select Committees in this
investigation.
Before we start, I would like to explain that you
are giving your testimony under oath; the reporter will take
down your testimony and transcribe it. You will have the
opportunity, if you want, to review your testimony once it
has been transcribed, and make any corrections or if there
have been typographical errors or if you were misunderstood,
you can point that out to us if you choose to review your
testimony.
accurately as you can. If you don't understand a question.
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1 let us know and we'll do our best to clear it up.
3 are presently a director of the United Nicaraguan Opposition;
4 is that correct?
5 A Yes. May I say just a few words? My native
6 tongue -- my native language is not English. I do think that
7 I speak it fluent enough to answer anything, but if I make
any mistakes, if there is something you don't understand,
9 please say so, so everything will be clear. Okay? I don't
10 need an interpreter, obviously, but I wanted to make that
11 clear, because there may be a lot of mistakes there.
12 My present pooition, I as a member of the
13 directorate of UNO; UNO is the acronym for the United
14 Nicaraguan Opposition.
15 Right now, there are two directors, is Pedro
16 Joaquin Chamorro, and myself. There is one vacant seat.
17 The director of UNO is the top executive authority
18 that has control on both the military and the political
19 struggle for the liberation of Nicaragua.
20 Q Does UNO incorporate the entire Nicaraguan
21 resistance movement at this time?
22 K No, sir. There are two other groups that arc
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1 outside UNO -that are of a certain importance. There are more
21 than two, but two that arc oC importance.
3 One is the southern opposition block, in Spanish
41 is called BOS, B like in boy, OS.
5 And then the Indian group called Misurasata.
6 Q BOS and Misurasata, neither group has
7 representatives in UNO; is that correct?
8 A For the time being, no. There are conversations
9 at this time to include it in what will be the Nicaraguan
10 resistance, we hope.
H Q I would like to briefly touch on these two
12 groups. BOS, the southern opposition block, who are the
13 leaders oC that group; do you know?
14 A They have a Cive-BC«ber directorate, but at
15 present the — I will say the key leader is Alfredo Cesar,
16 and, in Misurasata, the key leader is Brooklyn Rivera.
17 Q Are cither of those groups presently engaged in
18 Bilitary activities?
19 A Yea, According to what I know, both have minor
20 military activities inside Nicaragua.
21 BOS has about a^^^^^^^Bncn, aaybcl
22^^^^Hand Misurasata nav have up to^^^^^Hinside. And both
rand Misurasata nay have up to^H
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oC these organizations did receive aid in the last 9100
million aid package. Each one of thcB got|^^^^^H each.
So is^^^^^^H each.
Q Do they coordinate in any way uith the larger
military forces of the FDN?
A No, sir.
Q Or the southern group?
A Well — Misurasata does not. BOS operates in the
same region of Nicaragua, in the southern part of the
Atlantic Coast. And, due to that, yes, they do coordinate
with the southern front of UNO.
you also have your own political party; isn't that correct?
A Yes, air. In March of 1978 I founded a political
party in Nicaragua with other young professionals in
Nicaragua, and I have been president of that party since the
foundation.
The na»e of it is MDN, which stands for Movinicnto
DcBocratico Nicaraguense. That party is part of UNO, that is
an alliance, and has been part of UNO since we organized UNO
in June of 1985.
Q Does the MDN have any ailitary functions?
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A No, 3ir. The MDN is a political party with no
military structures. There arc members of the MDN who have
-- who are fighting inaidc Nicaragua, but, as part of other
forces like FDN forces, or in the southern front of UNO. But
the MDN, as such, has no military activities and no military
structure.
Q So the MDN is purely a political body?
A Yes, sir.
Q Do you have any involvement or are you a leader of
any of the military factions?
A According to UNO bylaws, the top authority in any
area of the struggle, any branch of the struggle, is the
directorate. So, according to the bylaws, I do have
authority and responsibilities. The fact is that, because of
my experience, which has always been in the civic-political
struggle, I have been kept fairly well informed of what is
going on. I, a few times, have looked at reports and budgets
about the military part. But I don't get involved in any of
the actual direction or the -- direction of the military
part. I am devoted mostly to political activities.
Q Do you have -- other than your general authority
over military operaljajptiia «s a,d4rcctor of UNO, do you have
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any particular affiliation or communication with the forces
in the south? The forces that are not part of the FDN?
A Not on any regular basis, whenever I occasionally
see the people inside there, I do talk to thca but not on a
regular basis.
In the past, when the so uthern front was command ed
by Fernando "El Negro" Chamorrc
had more regular contacts. But not formal contacts. But we
did talk to each other more frequently.
Q Yes.
A He left several months ago, about, what, maybe
seven, eight months ago. Since then the contacts with any
people in the south have been more irregular.
Q What was the name oC Fernando Chamorro's group, or
military unit?
A It has two acronyms. It is ODN-FARN. UDN-FARN.
The "UDN- stands for Union Democratica Nicaragua,
I think it is, which is the political branch of his
organization. FARN stands for Fuerzas Armadas
Revolucionarias Nicaraguenses, the Revolutionary Nicaraguan
Armed Forces. That is the military branch that was part of
the southern front under his command.
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1| Q Were you ever affiliated with UDN-FARN?
2 A No, 3ir.
3 Q Maybe we should go back and trace your political
4l affiliations.
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5j Starting with the formation of the MDN in 1978 and
6| going through the revolution and your present position, could
8 positions?
9 A Yes, sir. As I said before, MDN was founded in
10 1978, in March of 1978. Me becaac instrumental, and we were
11 the binding force to a larger coalition of political, labor
12 and private sector organizations that was called the "Broad
13 Opposition Front."
14 This broad opposition front was very important in
15 the overthrowing of Somoza.
16 I was instrumental to strike against Somoza, and
17 became involved in the insurrections against Somoza.
18 Due to my involvement in the broad opposition
19 front I was also a member of the political commission that
20 took — that was involved in the mediation of the OAS in
21 September of 1978. When the final insurrection against
22 Somoza took place in June-July 1979, then I was invited to
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1 discuss the formation of the governing junta as a
2 representative of my party, the MDN. And I did join and
3 became one of the five members of the governing junta of my
4 country, Nicaragua, from July 19, 1979 to April 22, 1980,
5 when I stepped down and resigned and became active in civic
6 activities inside Nicaragua, as the president of my party,
7 the MDN.
8 Q Stop there for a minute. Why did you resign from
9 the governing junta?
XO A I was fully committed to the original principles
11 of the Nicaraguan revolution, being effective pluralism;
12 nonalignmcnt in foreign policy and a well defined mixed
13 economy.
i
X4 It was clear, as time went by, that these
15 principles were betrayed by the key force in the revolution
16 that controlled all the weapons, that was the FSLN.
17 So, due to this betrayal of the key principles,
due to the clear detour of the revolution out of these
19 principles and becaae Bore totalitarian linked with the
20 Communist regimes, became more Communist, controlled by the
21 Marxist-Leninist, I decided to step down. I saw there was no
role for me inside the government.
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1 Q You referred to the FSLN, that's the Sandinista
2 party?
3 K Ye3 . Called the Prcnte Sandinista dc Liberacion
4 Nationalc; FSLN, what is known as Sandinistas, now.
5 Q So, in 1980 it became apparent that they were
6 controlling the country and that they had their -- they were
7 opposing a totalitarian. Communist form of government and
8 that's the reason you stepped down from the junta?
9 A That is correct.
10 Q Where did your activities take you from there?
11 A I stayed inside Nicaragua, in civic opposition to
12 the totalitarian Sandinista regime, for almost two years,
13 until in March of 1982. The emergency law was imposed on the
14 Nicaraguan people by the Sandinista regime. This emergency
15 law put censorship on the press and on the — on radio, the
16 television was a monopoly oC the Sandinistas, and political
17 activities of parties were not allowed. I thought this had
18 closed, 30 much, the space inside Nicaragua, political space
19 inside Nicaragua, and on top of that my house was attacked by
20 mobs and I wasn't allowed to leave the country. Several
21 times they stopped me at the airport and there were several
22 attempts to kill me. So I decided to go to exile in Costa
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1 Rica, with the key leaders of my party and to set the key
2 structure of my party, the MDN, in exile in Costa Rica.
3 I left Nicaragua the 23rd of March of 1982 and I
4 have not returned since then, to Managua. In exile in Costa
5 Rica, we set up our own organization, tried to contact
6 members and do the usual political activities that a party
7 does and we became, also, members of an alliance called ARDE,
8 where the key military leader was Commander Pastora,
9 p-a-3-t-o-r-a, and I was the key political leader in ARDE.
Iq\ For a period of one year, until May of 1983, all
11 our struggle was civic — or political, I should say. There
12 was no military activities under XRDE.
13 1 Q Can I interrupt there?
i
14 1 A Yea.
15 Q were there military activities taking place
16 elsewhere? For instance, in the north, at that time?
17 A Yes, sir. The FDN although I don't know if it was
18 called FDN at that time, but there were forces in the north
19 operating since March of 1982. In fact, the state of
20 emergency was "decreed"?
21 Q Decreed?
22 A ~ decreed by the Sandinista government because of
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some military actions that took place inside Nicaragua, which
showed the presence oC these forces, military forces,
operating in the north.
Q Did you have any knowledge of who organized the
military forces of the north?
A Well, I do have now because it is public to an
extent.
It was a group of Nicaraguans, some of them former
members of the national guard and some former Sandinista
combatants that were already also disillusioned in —
disillusioned with the regime in Nicaragua. And they
received some help fro« the United States government and some
froB some^^^^^^Hailitary
Q Did ARDB, or the MDN, receive any help from the
United States ^^^^^^^^^|or other foreign countries, during
this period March of '82 through May of '83?
Froa^^^^^^H nothing.
FroB the United States sometime in May or June of
1982, through Commander Pastora,
I think it was in
itartcd receiving some financing!
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■money was pcraanently given to us
9 until May-June oC 1984 when two things occurred; one, the
10 U.S. Congress cut off the aid after the aining of the ports
11 ^^^^^^^Hand the the CIA and, two, due
12 the reluctant attitude of Coamandcr Pastora to join forces
13 with the north, we split. He kept the ailitary forces that
14 were inside Nicaragua, and I kept the political activities
15 that were under ay responsibility. I got in contact with
16 Adolfo Calero, and the Indians^^^^^^^^Hto create
17 uBbrella organization that was called, at that tiae, UNIR,
18 U-N-I-R. And that is the origin of what is now known UNO;
19 that evolved and was founded in June of 1985^^^^^^^^^^^
20 Q So there was a period froa June of '84,
21 approxiaatcly? Is that when you broke up with Pastora?
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1 Q Until the formation of UNO, that you functioned as
2 an umbrella group under a different na«e, the UNIR?
3 A Yes. It was not as effective as UNO is now. It
4 was very loose. We didn't have offices or anything. It was
i
5 more a type of coordination, but the umbrella existed on
6 paper but did not exist in reality.
7 Q Throughout the period of your direction of ARDE,
8 what was the role of the MDN?
9 A Well, the MDN was the key political force in
10 ARDE. We did have a few members that got involved in
11 military activities in ARDE. By the way, the military
12 activities in ARDE started in May of 1983. Okay? But the
13 key role of the MDN was responsible for political activities
14 and the standing by political activities, publications,
15 seminars, missions to touch base with foreign politicians and
16 political parties; trying to group and organize the
17 Nlcaraguan exile communities, et cetera.
18 MR. PARRY: Can we go off the record for a
19 second.
20 (Discussion off the record.)
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Q Did you have any knowledge ot how Hr. Pastora was
procuring his aras, his weapons, during this tiae period?
A It was being aainly provided by the CIA.
Q And the aoney that he received was for food and
clothing? Is that what it was?
A It was aainly Cor food, transportation, the whole
apparatus of vehicles, and they did buy a £cw things here and
there that they thought that they could do better than the
agency like soae radio equipaent and soae sophisticated
cquipaent or things like that.
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1 Q How large was the military force oC ARDE during
2 thia period?
3 A At the peak, that must have been May-June of 1984,
4 Conmandcr Pastora claincd to have about^^^^^^^^Bf ightcrs
5 inside Nicaragua. And he had control about of half the Scin
6 Juan River, that is the river that serves as a border between
7 Costa Rica and Nicaragua.
Q ^^^^^^^^^H^^Hdid you or you
9 have contact with other representatives of the United States
IC government?
11 A Usually I will have contact with the Aaerican
12 ambassador as well as the political attache in the embassy.
13 In the beginning the ambassador was — is it Frank
14 or Fred MacNeil? Ambassador MacNeil, whichever. And then it
16 political matters and sometimes, also, the operation of the
17 hell
18 Q Any contacts with the NSC or with the White House
19 during this time period?
20 A With the NSC, I did meet — what was his name? —
21 A gentleman that now works with the Washington Times who was
22 in charge of Latin American policy there. A French name thai
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I don't recall.
(Discussion off the record.)
BY MR. PARRY:
Q Just before our break you were mentioning an
individual from the NSC that you had contact with during the
period prior to June of 1984.
A Yes, sir. Now I recall, his name is Roger Fontain
and that is the first person fro» the NSC that I met.
Later on, when the Kissinger Commission visited
Costa Rica in early 1984, I also met Colonel Oliver North and
he asked me to call him next time I was in Washington.
Q Is that the incident where he passed you a note in
a reception line?
A Yes. YC3. I was shaking hands with the people
that was inside the room: Dr. Kissinger, Ambassador
Kirkpatrick and others, and I shook hands with this gentleman
I didn't know and there was a piece of paper between his
hands and my hand where he has written "next time you are in
phone number and it was very embarrassing because I had to
shake hands with the next one and I didn't know what to do
with the piece of paper that was in my hand so I had to move
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1 it and put it in my pocket.
2 Q So that was your first contact with Oliver North?
3 A That was my first contact. I don't think I
4 contacted him in the next trip to Washington but in some of
5| my trips to Washington I did contact him. This must have
61 been in the middle of 1984 and I did pay several visits to
7 him during the second half of '84 and '85 and '86.
8 From July-August of '84 until sometime in the
I
9j middle of '85, if I don't recall it wrong, when there was no
10 U.S. aid, I asked Adolfo Calero to keep on providing funds to
11 cover the expenses of the political activities of ARDE, in H
12 Costa Rica. Being part of this UNIR, that is the first
13 umbrella organization. And this was very awkward and very —
14 it bothers me because, being a political leader, getting
16 effect of subordination to another Nicaraguan political
18 So, because of this I complained to several people
19 that I wanted to get some direct assistance and in several of
20 the meetings with Colonel North we discussed this and he
21 expressed that he will look and see if he could help me —
22 help us out; "us" being, mainly, the political movements, an
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organization that has stayed with mc in the split with
Commander Pastora, that took place in May of 1984.
Q Can we go back to that split?
A Yes, sir.
Q Your political organization split off from
Pastora 's military organization. Then there was — you
subsequently were united with other nilitary organizations;
is that correct? Fernando Chamorro's group — how did that
faction that split tzou Pastora?
A In ARDB, at the beginning, there were six
organizations. Some of thea stayed with Pastora. Some of
them split into factions, and sobc of them stayed with mc.
The ARDE political, that stayed with me, was ray
own party, MDN, "Negro" Chamorro's organization as a whole,
UDN-FARN; a labor group that split, half of a labor group
that split called STDN, and a Christian Democratic
organization that also split, and part of it — most of it
stayed with me in the political activity.
So, at that time from May of 1984 until UNO was
formed in June of 1985, these four organizations became part
of ARDE and one of them, UDN-FARN, did have a military branch
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but had very, very little military activities.
Q So you retained the name "ARDE" after the split
with Pastora; ia that correct?
A The split was such that there were two ARDEs . He
same names. This was very confusing.
Q And I talce it the funding you received first from
intended for your entire organization, both the political and
the small military unit of Fernando Chamorro's?
Calero, yes. It was intended to maintain the four
organizations that stayed with me that had mainly political
activities and a little bit of military activities under
Fernando Chamorro.
The second part, the ones that I received after my
conversation with Colonel North, were mainly to be divided
into two organizations only, not four. Two organizations:
MDN and UDN; both being political. Okay?
Q And the UDN, again, was under Chamorro?
A Yes, sir.
Q But it was his political activity?
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A Yes.
Q Olcay.
A Because there was humanitarian aid coming already
humanitarian aid was enough to take care of the military
branch under him called "FARM."
Q In terms of their food and —
A Food, clothes, medicines.
Q Do you know during this time if they received
additional weapons or ammunition and how that was paid Cor?
A They could have received some small lots of
ammunition, coming from private people. But let me make —
let mc state that part of the commanders of Pastora, in May
of 1986, came back to UNO. UNO had been formed already, and
they came back to us and they had — the forces have
froi^^^^^^^Bto maybc^^^Vactive they were
Sometime after that, 1 think the first one being
in September of 1986, there were several flights.
Q September of '86? Or '85? .
■86.
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Q Ju3t this past year?
A Yes, not too Car away.
Q AH right.
A Several flights took place in the second half of
■86. Let's put it that way. And they were mainly military
logistics, going inside Nicaragua for the southern front.
Q Did you have any comaunication with the private
benefactors, the persons making these air drops inside
Nicaragua?
A No, sir. I was inforaed only, a posteriori, about
everything that they received. And in general terms,
general,
Q Okay. You didn't have any role in communicating
what was needed in terms of military supplies for these
drops? You were just told after the fact that drops had been
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A No, 3ir. I had nothing to do with the
implementation or anything.
Q Do you know who would have? Would Fernando
Chamorro have communicated the needs oC the military?
A Logically it will be either hi» or someone under
hia.
Q Do you know who he communicated with?
A I could imagine it would be someone from the CIA
Ibut —
You are just guessing. Did he ever indicate to
you who it might be?
A No. I wouldn't know for a certainty.
Q IS there anything to make you believe that the CIA
would have been the intermediary in communicating that
information?
X Yes. I thi
cally makes me believe that they
■^I^^niJT^ril^Ihl^h^ called the -patriotic Americans" in
these efforts to resupply the troops from the southern front
Q Do you have any idea of the total amount of
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1 materials supplied, the value of the military supplies that
2 1 were delivered?
3 k Delivered where? To the south? Or to the total
4 operation?
5 Q To the south.
6 A I think the south received between five and six
7 flights. These flights usually will be 8000, 10,000 pound
8 flight.
9| The material that was delivered there sometime was
10 ammunition. There were a lot of boots and uniforms, and
11 there were some weapons. And my guess will be that the cost
12 of that will be in the neighborhood of $20 per pound. 13 If that is the case, every drop will be about 14$200,000, being five or six, will be in the neighborhood of
151 $1 million to$1.2 million.
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16 Q Okay.
17 A Plus the cost of transportation that I understand
18 was in the neighborhood of $20,000 to$30,000 each, because
19 of the risk it involved. So you will have to add to the
20 previous total about 100-, $120,000 more, about. 21 Q All right. Now, do you know whether the materials 22 supplied that you have estimated to have a value of about lINMlflED Ace-Federal Reporters, Inc. 202-347.3700 Nationwide Coveraop 800-^6-6646 489 UNCLASSIRED 28$1.2 million, were those paid for by these patriotic
Americans? Or had they previously been purchased by UNO or
the FDN?
A It was a mixture of the two. It was not — it
wasn't UNO, because at that time UNO did not have any money
for military purposes.
Q Okay.
A It didn't have any military aid. So it could come
from only two sources .
What they, "patriotic Americans," or FDN who
bought it previously and it was in FDN warehouses. It could
well be that in one flight it could be so«e things from one
side, some things from another.
Q Do you thinlc there were some of each?
A Yes. I don't know where it came from but this is
what I have learned.
Q It could have been cither or both? Is that what
you are saying?
A That is correct. Either or both.
Q Do you have siallar knowledge with respect to the
total supply by the patriotic Aaericans? Not just in the
south.
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1 A I was told by Adolfo Calcro that the total amount
2 of flights were between 20 and 25. That being the case, and
31 applying the same arithmetic, that will be between $5 to$6
million in total, including goods and transportation costs.
5| Q What was the period of time of these 25 flights?
6 Do you know that'
7 A I only have knowledge of the ones in the south.
The ones in the south took place, I think, between June to
9 when the Hassenfus accident took place, that I don't recall,
10 Q Okay. Late October?
11 A Is that when that occurred?
12 MR. BUCK: October 5th.
13 MR. BERMINGHAMs October 5.
14 THE WITNESS: Until October ~ then.
15 BY MR. PARRY)
16 Q All right. Do you know the names of any of the
17 individuals involved in the supply effort by the "patriotic
18 Americans"?
19 A No, sir,
20 Q You didn't have any direct contact?
21 A No. AdolCo Calcro told me once, in late November
22 of 1986, that the person that handled all of these was
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Captain Cooper —
Q Okay?
A — who was the pilot in the plane that was dropped
down in — the Hasscnfus flight.
Q Did you ever discuss the supply operation with
Colonel North or any of Colonel North's representatives?
A No, sir.
Q, He never indicated any connection or control over
the "patriotic Americans"?
it.
Q Okay.
A But, since I was not involved in it there was no
detail or anything.
Q Let's go back to the funding now.
A Yes.
Q Prior to money received from Colonel North, you
A Yes.
Q Do you recall approximately the total amount of
A Roughly 9600,000.
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1 MR. PARRY; Can we raarlc this as the first
2 exhibit.
3 (Robelo Exhibit 1 identified.)
4 BY MR. PARRY;
5 Q Mr. Robelo, I'm going to show you a act of
6 documents relating to what wc believe are the funds you
8 compute^ printouts, based on bank records that Adolf o Calcrc
9 has provided to the com«ittee3. And the subsequent document
10 are the individual documents evidencing the various
11 transfers.
12 Would you look at these and first tell me if the
13 numbers on the computer printouts would show the dates and
14 amounts of the various transfers from Adolf o Calero 's
I
15 accounts appear to be accurate? j
16 A They appear to be accurate according -- to the
17 best of my knowledge, yes.
18 Q Now, the accounts that you had set up for
19 receiving these funds was in which bank?
20 A
21 Q And the name on the account was?
22 A I don't recall if this one is the same
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1 I^^^^^^^^^^^^^^^H account, or could be a personal account
2 under my name. I know about the others but not this one.
3 (Discussion off the record.)
4 THE WITNESS: Hhat we were talking about?
5 BY MR. PARRY:
6 Q You said you didn't know whether this was your
7 account or the private account —
8 A After seeing the records, it was clear that this
9 was transferred to an account, special account, under my name
10 ^^^^
11 Q So that was not the same account later used by
12 Colonel North?
13 A No. It is not.
14 1 NR. PARRY: Can you aark this as the second
15 exhibit?
16 (Robelo Exhibit 2 identified.)
17 BY MR. PARRY)
18 Q The other documents aarked as Exhibit 2, the othei
19 documents, are documents which you yourself provided to the
20 committees at an earlier date. Those are the documents
21 representing the the monies received through Colonel North;
22
.3 that correct?
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Yc3. These arc the credit notes ofl
|of cable transfers to the account of
Ithat were the result of my conversation
with Colonel North requesting direct financing of military
operations -- I'm sorry -- political operations of MDN and
UDN. The total amount being $225,000 minus cable cost expenses that account for a few dollars each time. Q How were those funds divided between MDN and UDN? A At the beginning there arc some transfers that ar larger than the normal$10,000 per month because we had run
into some debts and we wanted to clear that out.
Later on it will be 910,000 and it was usually
divided 50:50.
I say "usually" because in the beginning I don't
think it involved any of UDN-FARN; and also because at the
end, the fact that humanitarian aid was coming to UDN-FARN,
also meant that it stopped, earlier, that November of 1986.
In other words, in the last month it was not
divided. At the beginning it was not divided. But in the
middle it was divided half and half.
Q There appears to be substantial drop off in the
amount of funding you received throufllL^Colonel North as
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they both intended to finance the same operations?
A No, sir.
Q What was the difference?
were to sustain ARDE as a whole. That, as I mentioned
before, it is four organizations and a larger structure as
such.
These funds, from coaing — because of ay talks
with Colonel North -- was only to finance the political
activities of two organizations, not four. And had nothing
to do with ARDE as a coalition.
Q Did ARDE dissolve when UNO was formed?
A Yes, sir. ARDE Stopped operating when UNO was
founded in June of 1985.
Q Okay. Approximately at the same time. I sec the
last contribution through Calcro came July 3 of '85?
A Ves.
Q So that approximately coincides with the
dissolution of ARDE and the formation of UNO?
A Of UNO.
Q Is that correct?
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A That is correct. The money coming because of my
conversations with Colonel North that are in Exhibit 2,
started more or less at the same time UNO was formed and they
were intended only for political activities of the two I
organizations that I have mentioned.
Q Do you know how the other two organizations that
were in ARDE — did they continue in existence, continue to
A Yes. Only through UNO, whenever they were
involved in the structures or projects of UNO.
Q Okay.
A In the case of my party, the MDN, we kept a
separate office in San Jose, Costa Rica, that we still have.
And for party activities we use that office and most of this
money, received through Colonel North, the part that was for
MON, was used as party funds to cover political expenses like
rent, telephone bills, salaries for the receptionist, the
office administrator, the night watch; publications — we
have a bimonthly publication called Rescatc; some seminars of
members of ay party; some missions to foreign countries,
things of this nature.
Q Did you yourself rcceiva.^^^lary out of these
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2 A No, sir. I have never received any salary because
3 of my work as a politician. I have never received any salary
4 out of either my party or UNO or ARDE. I had ray own savings
5 out of my work in Nicaragua, and that's what I live from,
g Q^^^^^^^^^ think, has indicated that he received
7 money from Colonel North for his personal expenses and I
think Adolfo Calero has indicated the same thing, in terms of
9 a salary. But you never received that type of funding?
10 A No, sir. Never ever .^^^^^^Hmade it public to
11 us, the directors of UNO, in a meeting in May of 1986 in
12 Miami, that in order for him to cover his living expenses as
13 well as some political expenses, he was receiving some
14 money.
15 That is not the case in this money that
16 ^^^^^^^^^^^^Breceived. This is money for
17 organizations, specifically and mainly the MDN and in some
18 part, in a minor part, UDN-FARN.
19 Q All right. Do you — at this time, do you have
20 any outside interests, activities, to generate income for
22 A Yes, sir, I do. I have a coffee farm in Costa
yiUSSIFIED
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1 Rica that I bought many years ago. I have intcrcat in a
2 sugar mill. I have interest in —
3 Q In Costa Rica?
4 A In Costa Rica, yes. I have interest in a larger
5 coffee farm in Costa Rica. I have savings accounts in Costa
6 Rica, time deposits in Costa Rica where I live from.
7 Q And your family lives in Costa Rica at this time?
8 A Yes. My family in Costa Rica and I am divorced
9 and my ex-wife has a house and has her own living.
12 A I am a chemical engineer and I have worked from
13 1961 until 1979 as an executive in an agribusiness complex
14 that produced cooking oil out of cottonseed and that had
15 investments in cotton plantations, banking as well as what I
16 have mentioned that I still have in Costa Rica that is a
17 product of that agribusiness complex.
18 Q Let's go back to the money supplied by Adolfo
19 Calero. Did he tell you what the source of that money was?
20 A Private donors that wanted to remain anonymous .
21 Q Did he indicate whether they were American
22 citizens or from foreign countries?
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1 X No, sir.
2 Q Did he indicate that he knew anything beyond what
3 he told you?
4 A He didn't indicate anything. Just mentioned
5 that. So I could not say if he knew or did not know.
6 Q He didn't give you anything —
7 A No.
8 Q You just assumed that they were private donor .
9 Did he Bcntion who raised the Boncy Cor him?
10 A No, sir. There were so«c names that were public,
11 like General Singlaub and other people but he mentioned the
12 fact that most of these contributors will want to remain
13 1 anonymous. Wanted to remain anonymous.
14 Q Again, with the money received through Colonel
15 North, did you understand anything with regard to the source
16 of those funds?
17 A Colonel North in one conversation explained that
18 these were foreign, private donors.
19 g So with the money in th^^^^Bac count, you
20 understood they were foreign private donors. The money from
21 Calero they were just private donors, could have been foreign
22 or —
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1 A That is precise.
2 Q And when they say "foreign" they mean non-United
3 States, I assume?
4 A That is correct.
5 Q Beyond that did he identify the countries or the
6 individuals that were contributingl
7 A No, sir.
Q The first check in this Exhibit 2, or the first
9 wire transfer, comes from a John Ramsey; is that correct?
10 A That is correct.
11 Q Do you know anything about Mr. Ramsey, or how it
12 came about that he wired, was it 910,000?
13 A No. At the time I received this money I knew
14 nothing about who he is — who he was. A posteriori, now, I
15 received the visit of Rich Miller, the 9th of April of this
16 year. Hhen I asked him who John Ramsey was, he told me he
17 was an American contributor and he knew who he was. But at
18 the time that I received this, I honestly didn't — did not
20 notes.
2l| Q This was arranged by Richard Miller? This
22 1
transfer?
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X No. No. I don't know.
Q You don't know?
A I don't know.
Q What was your connection with Richard Miller?
K Richard Miller was introduced to ne by Colonel
North, cither in his office at the White House or else in a
telephone conversation and then later on I went to Miller's
office.,
Miller acted aorc like an adviser on visits to the
different -edia in Washington, like television and radio and
newspapers.
He did accompany me several tiaes to visit a
journalist or televisions or radio stations, and they did
■ake soae appointments for me.
When 1 say "they" it means the organization he has
with another person that I know fairly well, Frank Gomez.
Q Was it your understanding at the time that
Mr. Miller or Mr. Gomez had anything to do with the money
that was sent to youi^^^HH^^ account?
Colonel North.
Now, a posteriori also, I have seen here in the
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1 second and third transfer, the name "International Business
2 CoBinunications" appears.
3 Q Right.
4 K These were the two largest money transfers because
6 pay. Mr. Miller visited — visited me last April 9th here in
7 Washington, and asked nc to write an aclcnowlcdgment of this
8 money toeing received. I promised that I will acknowledge
9 that and give copies of these transfers — photocopies of
10 these transfers.
11 Again, I found that this money was coming from
12 IBC, only when I looked at my files in order to get these
13 records out in order to cooperate in this investigation.
14 I didn't pay attention to that when I received it.
15 Q Okay. So I take it that prior to April 9th of
16 this year, you had no idea that John Ramsey had any
17 connection with Richard Miller whatsoever?
18 A That is correct.
19 Q You didn't know that Richard Miller or Frank Gomez
20 were in any way connected with the funds being provided to
you^^^^^Bccount?
22 A I did not know at the time the funds were providcc
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1 because I didn't look in detail on the credit notes.
2 When I looked for the credit notes, in order to
3 cooperate with the investigation, I found those names and,
4 since I have seen those names in the newspapers, then it
5 became —
6 Q After the deposits from International Business
7 Communications, there are deposits from Lake Resources.
8 Again, you didn't know who Lake Resources was or who had
9 control of that account?
10 A No, sir. I had no knowledge and there are three
11 deposits from Lake Resources, each one of 915,000 and I
12 didn't know who Lake Resources was. I know now because of
13 the publications in the newspapers.
14 Q All right. Subsequent to the transfers that
15 specifically identify Lake Resources there are some documents
16 that don't specifically identify the source. They cither say
17 "one of our clients" or "El Misao," do you know who the bank
18 was referring to or this document was referring to when it
19 says "one of our clients" or "El Mismo"?
20 A No. I have no idea. After the transfer from Lake
21 Resources, all of the rest don't have any identification of
22 who ordered these cable transfers. It only gives the name of
UNCUSSIHED
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and I
1 the bank.
21 In some cases it isl
i I
3| think, after seeing here it is really^
4i^^^^^^^^H Because the bottOR
5 a mistake here, it'
6 Some say"^
that 's^^^^^^^^^^^^^^^^^l some these come £roa
8 Suisse, Geneva. But all of them say by order of "El Mismo"
9 which, in Spanish, means "the same." So there is no more
10 information.
11 When I received this money and it was for monthly
12 resources, at that time I marked them down with the names of
13 the months that it corresponds with at the bottom. Like, in
14 here, in the third receipt I have "August-September." And
15 then it says, "October." "November." Et cetera.
16 There were some cases when there were delays, and
17 then two monthly installments will come in one, like the one
18 of the 25th of August of 1986 that covered July-August.
19 Instead of being for $10,000 it is for 920,000. 20 Q Has the last payment received that of November of 21 '86? 22 1 A Yes. The l^jt Ji^yflWV^MPtrrt^ncd November 4, Ace-Federal Reporters, Inc. 505 30686.0 BRT UNCLASSIFIED 44 1986. According to my records, that is the November monthly resource for the political organizations. However, in the credit note it's the only one that has a reference saying "October *86." Q Since this last payment, either October or November "86, how has MDN and UDN been funded? A Well, UDN, I don't know. UDN, I don't know. MDN has, in addition to this, received for quite soBC time private donations from Nicaraguans. And, in fact, everyone — every MDN member that is involved in any political activities and receives, because of his work a stipend, according to the magnitude of the stipend, has to give a certain percentage to the party. Q I see. 207-147-3700 Nationwide rovrraor 506 30686.0 BRT UNClASSm Q Has there any period oC time between "84 and '85 or '86, that the CIA said they could not provide you with funds? A Oh, yes. The CIA has not given funds to the MDN; no funds during late '84, I aa sure. Nothing, I think, during 1985. Maybe in early 1986 it has started, or the ■iddlc of '86. Q I take it coinciding with the expiration of the restrictions on the CIA under the Boland aaendaent; is that your understanding? A Yes, that's ay understanding. Q Now, the Nicaraguans that are funding the MDN, I take it these are all Nicaraguans in exile? A Yes, sir. wmm 507 30686.0 BRT UNCUSSIRED Q Prior to October 24th of '86, during the period of the Boland a«end«ent, do you know if the CIA provided any funds to the military operation in the south? A No. Nothing. I know nothing — I know of nothing. First, fro« May of 1984 until May of 1986, there was al«ost no military operations in the south because in the split with Pastora, ComBandcr Pastora has retained most of the forces so there was no military forces in the south. Now, from May of 1984 on — from May of 1986, I correct myself, on, there was some humanitarian aid. And that took care of the nonlcthal part of the military UNCLASSinED Ace-Federal Reporters. Inc. 508 30686.0 BRT UNCUSSIREO 47 1 operations. 2 The military ones, as I have stated before, came 3 from what I call the Hasscnfus flights that took place and 4 they were the ones responsible for lethal logistics. 5 MR. PARRY: I'm just about finished with the 6 questions I have. I would just like to go back and ask you 7 about individuals and then I think these two gentlemen might 8 also have some questions. But let's go back to Colonel 9i North. 10 BY MR. PARRY: 11 Q You met him in early 1984 in connection with the 12 Kissinger Commission and he passed you a note. 13 Did you follow up with him solely because of that 14 contact or did other people recommend that you contact 15 Colonel North? 16 A Out of that contact I developed a friendship and, 17 usually when I came to Washington, I would pay a visit to his 18 office because of the reality that Colonel North was very 19 knowledgeable about Nicaragua; very knowledgeable about the 20 policy of the U.S. government, and his knowledge was not only 21 military but also political. And knowledgeable about the 22 resistance structure and problems. So it was a very useful UNCUSSIFIED Ace-Federal Reporters, Inc. 509 30686.0 BRT UNCUSSIHED 1 person to talk to because of his knowledge. 2 Q So from that first contact the relationship 3 developed on your own initiative? You took it upon yourself 4 to contact him when you were in Washington? 5 A Yes, sir. Yes, sir. 6 Q Who else, working for Colonel North, did you have 7 contact with? 8 A Working for Colonel North? 9 Q Or who did you understand was working with Colonel 10 North? 11 A I understood first, Robert Owen. 12 Q When did you meet Robert Owen? 13 A I think I met him at Colonel North's office. I 14 Lfcfs get these dates straight. Could I go off the record? 15 MR. PARRY: Sure. 16 (Discussion off the record.) 17 THE WITNESS: In March of 1985. He was presented 18 to me as a private citizen, helping Colonel North to get aid 19 for the Nicaraguan resistance from the U.S. Congress. 20 BY MR. PARRY: 21 Q After that how many times did you see Robert Owen, 22 and what was his role? Ace-Federal Reporters. Inc. 202-347.370O Nationwide Coverage 800-335-6646 510 30686.0 BRT UNCLASSIFIED 49 1 A I saw Robert Owen several tiacs here during — 2 from March '85 to October "85. Usually at Colonel North's 3 office. Maybe a couple oC times outside his office. 4 Later on, when the humanitarian aid was approved 5 in September-October 1985, because of his knowledge about 6 Nicaragua and Central America, we requested from the 7 Nicaraguan Humanitarian Assistance Office, NHAO, that was 8 headed by Ambassador Ducmling, D-u-e-m-1-i-n-g, I think — 9 that Robert Owen be included in the personnel as an expert, 10 with expertise, or a man that will help us in getting the 11 humanitarian aid moving and getting it to Central America in 12 the best way. 13 Q So you recommended Robert Owen for the position? 14 A We, the three directors, did. 15 Q Prior to this time, though, you understood that he 16 was working for Colonel North? 17 A I understood that he was a private citizen 18 cooperating with Colonel North on Colonel North's efforts to 19 get aid for the Nicaraguan resistance. 20 Q Did he with V^u^^^^^^^^^^Hi 9^^°^ ^^<^ 21 time he became involved with the humanitarian aid? 22 A No, sir. I don't recall. But he did meet with me Ace-Federal REPORtERS. Inc. 202-347.3700 Mationwide Coverage 800-336-6646 511 UNCLASSIFIED 50 two or three times ^^^^^^^^^^vaftcr he became involved in the logistics of the humanitarian assistance; yes. Q What were the purpose oC his visltsi A To give mc a report on how the humanitarian assistance was flowing, both to the north and to the south. Q Other than Colonel North, were any other individuals involved? Did you have contact with, that were involved with Colonel North? A I mentioned that I met Rich Miller and Frank Gomez. Q All right. A Both from IBC, through Colonel North. And that they helped mc out in getting some interviews with newspapers, television, et cetera. Q Along that line, did you ever meet Mr. Channell? A I met Mr. Spitz Channell in March of 1985, I think it was. But not through Colonel North but through FDN. I ■et Mr. Channell at FDN headquarters here in Washington at Jefferson Street in Georgetown, they used to have headquarters . I saw Mr. Channell a couple of times when we paid visits to President Reagan and there were large gatherings of Ac^'T^S^TIal' Reporters. Inc. 202-347.3700 Nationwide Coverage 800-336-6646 512 30686.0 BRT uNfiussra 51 1 people that supported the cause of the Nicaraguan resiGtance, 2 and Mr. Channcll was there; General Singlaub was there. But 3 these were more of a protocolary formal gathering where no 4 substance was discussed. 5 Q Did you ever understand that Mr. Channell had a 61 role in providing funding for the F0N or for the UNO? 7 K No, sir. My understanding was that he did 8 fundraising to have a political campaign to help the aid to 9 Nicaraguan resistance. But I knew of no direct funding of 10 UNO ~ to UNO, I mean. 11 Q This would have been for American political 12 campaigns? Is that what you understood his role was? 13 A Yes, sir. I did watch television advertising, 14 that was paid for by some organizations funded by the 15 organization of Mr. Channcll. 16 Q Were you ever told or did you ever understand that 17 either Mr. Miller or Mr. Gomez or Mr. Channcll were involved 18 in procuring weapons or arms for any Contra groups? 19 A No, sir. 20 Q No reason to believe that that happened? 21 A No. I had no reason to believe and I would have 22 not known because that's not the area that I had. ..UNCUSSiEP Mannnwidf Tnv 800-336-6646 513 30686.0 BRT UNCLASSIFIED 52 1 Q How about Jane McLaughlin, did you ever meet her? 2 A Yes. I met her at a reception put out by Polcmka 3 in one Washington hotel. I don't recall the name, for 4 Colonel Enrique Bermudez, from the FDN . We had met several 5 times to, in general, discuss the Nicaraguan resistance i el situation and to discuss how the aid to the Contras was. I 7 Q What did you understand her role to be? 8 A She was an executive in Spitz Channell's 9 organization in charge of fundraising specifically for aiding 10 the resistance — aiding — for aid to the resistance, I 11 should say. Do I make myself clear? 12 She was an executive in Mr. Spitz Channell's 13 organization to do fundraising that will pay for political I 14 i advertising or propaganda in this country to help create 15 favorable public opinion for the aid to the Nicaraguan 16 resistance. X7 Q But again it was your understanding that they were 18 not raising funds for either «ilitary or nonmilitary aid 19 directly to the Nicaraguan resistance? 20 A My understanding was that she and the organization 21 she worked for were not fundraising for any military 22 activities and were not fundraising to help UNO directly. Inc. 514 30686.0 BRT UNCLASSIFIED 53 1 However, Spitz Channell's organization did have some 2 financing to IBC, where Rich Miller and Frank Gomez worked, 3 and they were helping ua doing some lobbying and with the 4 press here. So, indirectly through that service they were 5 helping us. 6 Q All right. 7 A On top of that, when Mr. Carlos Ulvert was the person in charge of our UNO Washington office, he, 9 Mr. Ulvert, informed me that through a conversation with Rich 10 Miller, he, Mr. Ulvert, has received some funds to cover the 11 expenses of the UNO Washington office. 12 Q From Richard Miller' 13 A Yes, sir. From Richard Miller. 14 Q Do you know what the amount was? 15 A Close to 9100,000. 16 Q This was at what time? 17 A The first half of 1985. 18 Q Is that the only instance you know of? Or knew of 19 that money was coming directly from Miller — from Mr. Miller 20 to any of the Nicaraguan groups? 21 A Plus two small incidents, two small events when 22 they gave me some money. uNoussm Ace-Federal Reporters. Inc X) Nationwide Coverage 515 30686.0 BRT UNCLASSIHED 54 1 Q Maybe we should talk about that. In addition to 2 the money that was put into th^^^^^Haccount which you 3 understood was arranged by Mr. North, were there any other 4 contributions of cash made to you or your group? 5 A Two incidents happened. One took place in, I 6 think it was April 4, 1984. Could it be '84? No, no, no, 7 no. I'm wrong. It has to be April 4, 1985. Yes, '85. It 8 has to be '85. 9 That was the first time when I act with President 10 Reagan and — yes, that's correct. A Lear jet was sent down 11 to Costa Rica to pick bc up. My understanding was that both 12 Colonel North and Rich Miller and his organization, had to do 13 with the contracting of that Lear jet that went down to Costa 14 Rica to pick me up. And my understanding is that they paid 15 for whatever coat that was. 16 Due to an accident that the airplane suffered, 17 when bringing me back in the Caribbean, we have to land in 18 Cancun in an emergency landing and I came very late for the 19 meeting with the President and without any sleep the whole 20 night before. They have made reservations for me at the 21 Hay-Adams, that is a very expensive hotel. And I complained 22 that I didn't have money to pay for that expensive hotel and. Ace mmw 516 UNCUSSIFIED 55 1 through Colonel North, one of hia assistants that I don't 2 recall gave rae an envelope with 9300, i£ ray memory doesn't 3 fail. I think it was three 9100 bills; three 3100s. 4 The second incident is sometime, it could be 5 earlier or later, I don't know. But I came to Washington to 6 lobby Congress and my plans were to stay here for only a few 7 days and I had to stay for three weeks at a hotel called 8 Ramada Renaissance on M Street and because of my credit card 9 hit the limit I was very annoyed and I requested from Rich 10 Miller to help mc. And he did send me eight traveler's 11 checks of 9100 each, totaling 9800 that I deposited in the 12 hotel account so I could stay for the rest. 13 Q Going the other way, were you ever asked to give 14 money to Colonel North or to Richard Miller or any of these 15 people? 16 A No. Never. 17 Q Do you know if any of the Nicaraguan resistance 18 groups were ever asked to give money to any of these people? 19 A No. Never. 20 Q How about General Secord, have you ever met him? 21 A No, sir. Never. 22 Q You mentioned you had met General Singlaub. What Ace-Tederal Reporters, Inc 517 30686.0 BRT UNCLASSIFIED 56 sort o£ contact have you had with hi«? A I had met General Singlaub two or three times in my life. The first tiaie was in Miami when ho invited me for dinner with several other Nicaraguans at the Viscount Hotel to discuss an event where the several Nicaraguan leaders of the resistance will get together and where my name was includc;d without my previous consent. After that, I think I had met General Singlaub twice in the White House on these protocol gatherings with President Reagan and in those cases we only said hello. Q You haven't had any communications with him regarding military supplies or — A Never ever. 518 30686.0 BRT Q How about the State Department? Hhat contact have you had with the State Department in Coata Rica, other than the ambassador? A Hell, I usually talk to the political attaches there. I talked to Mr. Charles Harrington who works there, and who is continuously asking me to meet with visitors from Congress and others. And I have met with the political attache. I don't recall his name. Q How about Elliot Abraas . Uhat has your contact been with Elliot Abrams? A Whenever I come to Hashington it is almost certain that I will pay a visit to Mr. Abrams and discuss with him the U.S. policy towards Nicaragua. We usually will meet with several of his staffers and assistants. i Q Mould you discuss the same things with Abrams that you would with Colonel North? A I will say my discussions with Mr. Abrams are Ace-Tederal Reporters, Inc 519 30686.0 BRT UNtlASSffl 58 usually more on the political side. With Colonel North, because of his background we did get involved in more of the military strategy. In broad terms, but military. With Elliot Abrams we seldom discussed any military matters because it's not what they handled. Q Did Elliot Abrams ever know about the funding that you were receiving through Colonel North? A I don't know. Q You never discussed that with him? A Never ever. Q Did you ever discuss the patriotic Americans supply network with Elliot Abrams? A I don't recall ever discussing it. Q Did you discuss those things with anybody at the State Department? A No. MR. PARRY: Okay. I don't have any more questions. MR. BERMINGHAMt I would take a few minutes, if I might uNtussra Ace-Federal Reporters, Inc. ym.Ml.Mnn Nannnwide Coverage 800-336-6646 520 30686.0 BRT (imnssffl 59 EXAMINATION BY MR. BERMINGHAMt Q There has been a lot of publicity about the airport — air atrip John Hull at Santa Elena; John Hull's former aircraft, the Santa Elena air strip, a group of Cuban: allegedly active in Costa Rica. What is your view or knowledge of those? A I have met Mr. John Hull, H-u-1-1 — right? Q Yes. A Several times. He's an American who has a farm ir Costa Rica. I have been on his farms Later on I have not seen any of — I have not seer Mr. Hull — I don't think I have seen him in maybe the last three years. Q' Do you think he's been inactive in the support of the Democratic forces? A He has always been a man that is willing to help the struggle — the Nicaraguan resistance. I know nothing about activities in his farm that has to do with Cubans. Only very broad rumors, in Costa Rica, about some Cubans Ad PORTERS, InC 521 30686.0 BRT ifiussro 60 1 there. And that's not — that is not in recent months but 2 several months ago. 3 Q Let me ask you about the air strip at Santa 4 Elena. Did you have any involvc«ent in that? 5 A Which one is the one in Santa ElenaJ 6 7 Q Yes. A I only know what appears in the Costa Rican 9 newspapers. 10 Q One last question Cor the record. There has been 11 a lot of talk about drugs playing a very important part in 12 the raising of funds. Would you like to make a statement 13 about that Cor the record? 14 A Yes. I know oC no people involved in ONO that had 15 any connections with any person involving drugs. 16 Now I know oC people in -- one person who is in 17 BOS, in the southern opposition block, who, because of a television program in CBS called 57 Best, says that I have 19 some involvement in late 1984 with a drug dealer that is in 20 jail in Miami. But no one Crom UNO organization have I ever 21 known oC being involved in anything that has to do with drug 22 traCCicking. B AcWederal Reporters, Inc. 522 30686.0 BRT WlftSSW „ 1 2 3 4 5 1 «! 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 Q You State no one in UNO. Would you say, other than this man in BOS, would you know about any other from any organizations? A I do remember one incident, a long time ago, when I was in ARDE, that a Nicaraguan in link with the struggle in the south, by the name Sebastian Gonzales, had to flee Costa Rica to Panama because he was accused by the Costa Rican authori.ties of being involved in drug trafficking. He lives in Panama and has lived in Panama for the last two years at least. And he was not directly involved in the struggle but he was a Nicaraguan exile with some contacts with Commander Pastora. Q But when you were active in the Costa Rica with ARDE and the other organizations you saw no funds coming in of drugs or knew of no drug operation? I A Never ever. No, sir. Never. I MR. BUCK: I had some questions. * MR. PARRY: I had just one question that occurred to ne. referred to 30686.0 BRT people by code names. Do the naaea "Spark" or "Clutch" have any significance for you? A What? Spark, S-p-a-r-k? No. Or Clutch, C-1-u-t-c-h? No. What is that, my code name? Might be. I don't know. No. EXAMINATION BY MR. BUCK: Q Have you ever heard of the code naac "Green"? A I met with Jane McLaughlin two or throe weeks ago and she said that "Green" was the code name for Oliver North. But I have known about that code name only recently. Q Did you — do you remember a conversation with Jane McLaughlin in which she asked you about your organization receiving Singlaub-typc aid? A At one time she was very surprised because she asked me the assistance that Spitz Channell's organization was giving to us and according to my knowledge there was no ce-FederalReporters, Inc. 524 30686.0 BRT UNCLASSIFIED 63 [ 1 such aid. And she was very surprised. 2 I do recall it, not in detail, but yes. Because 3 she was surprised. What do you mean we arc not helping you? 4 I said no, you are not helping us. Maybe you arc helping us 5 the same way General Singlaub's organization is helping us 6 but nothing oC significance. Because I knew nothing about 7 private funding. 8| I would like to add one thing that may be ot 9 interest to you. In August ot 1985, at a meeting ot UNO directoratc^^^^^^^^^^^^^^^^^^^lwhere AdolCo Arturo Cruz, and myself were present ,^^^^^^^^^^^^^^^^1 12 ^^^^^^^^^^^^^^^^^^^H we came to an 13 funds, irrespective of the origin, should be channeled and 14 controlled by the directorate in a collective way. In other 15 words, would not be individually controlled but collectively 16 controlled among the three of us. 17 In subsequent meetings that usually were every 18 month, I will say September, October, November, December 1985 19 and maybe January of 1986, I asked Adolfo Calero, who was the 20 one mostly involved in the handling of private funds, 21 especially with my previous experience of receiving money 22 from him, what was the situation of funds coming to — UHCUSSIHED Ace-Federal Reporters, Inc. 525 30686.0 BRT UNCLASSIFIED 64 1 private funds coming to help the cause? And the answer, in 2 each and every one of those meetings of the directorate, 3 was: I have received no funds and there is no money 4 available to be disbursed by the directorate. 5 I interpreted this as Adolfo not wanting to share 6 that responsibility with us and I gave up asking him more 7 about that. 8 Q Would you have known about weapons that would have 9 been delivered to your — to a military group associated with 10 the southern front or military groups associated with the 11 northern front? 12 A I did know, as I have expressed, of some air drops 13 that were made to the southern front and they usually will 14 inform mc of how many bundles and how many pounds. I did not 15 receive any report on the details of what those bundles 16 contained. 17 Q What I'm wondering is, you mentioned that you 18 believe they were paid for by private donors. 19 A Yes, sir. 20 Q And we have Mr. Channell raising money from 21 private donors. But at this point in time you have not made 22 a connection between Mr. Channell "s activities and the PORTERS, Inc. 526 30686.0 BRT UNCLASSIFIED 65 private donors and military air drops? K No. I did not make such connection. Besides that, my understanding was that Mr. Channcll's fundraising was devoted mainly for political campaigning in the United States to move the public opinion in this country in favor of Contra aid. Q Uho told you that or how did you develop that opinion? A Because I saw the advertising that appeared in the television continuously and I saw how he was doing publicly these moves to change the public opinion. And I honestly didn't think of any links that he may have with providing funds for weapons or military logistics. Q So, when you saw him with Colonel North, again your assumption was that he was helping out in a political sense and not — A I don't recall ever seeing Spitz Channcll with Colonel North. But in the large meetings with the President I don't recall ever seeing Spitz Channell in Colonel North's office. MR. BUCK: Okay. I have no more questions. MR. PARRY: Just one. AcE-Fi TERS. Inc. 527 30686.0 BRT UNCLASSIFIED 66 1 THE WITNESS: There's always a last one. 2 EXAMINATION f 3 BY MR. PARRY: 4 Q What is your opinion of the efficiency of the 5 private supply network? How did it operate? The airlifts? 6 A It became evident after the drop of the Hassenfus 7 flight, because of the documents the crew carried and because 8 of the pattern that they flew, that this was not a very well 9 prepared and secure and effective operation. To the 10 contrary, it became evident that it was very unprofessional. 11 But I didn't know nothing at the time of the flights. 12 Q Prior to the Hassenfus, you hadn't heard 13 complaints? I 14 A No, Sir. 15 Q Anything about the ammunition not matching the 16 weapons that were dropped? Things like that? 17 A Maybe once or twice Commander Chamorro told me 18 that they had dropped materials that were not of use to the 19 troops. Not necessarily not matching but maybe sometimes in 20 excess of what they really need, so it only meant more weight 21 to the insurgents. 22 Q Were they always dropped in the right spots? UNCIASSIRED Ace-Federal Reporters, Inc. •)n7-U7.17nO 528 30686.0 BRT UNCLASSIRED 67 A oh, no. There were tremendous problems because there will be drops that will not coincide with the dropping zone. In many cases there were bundles that were lost because o£ not dropping in the proper zone. Q Fernando Chamorro would communicate this to you? A Yes, sir. Q Did you ever meet anybody named Max Gomez or Felix Rodriguez? A No, sir. Never. Q Rafael Quintcro? A No. MR. PARRY: Olcay . No more questions. (Whereupon, at 12:20 p.m., the deposition was concluded. ) UNCLASSro Ace-Federal Reporters, Inc. 529 CERTIFICATE OP NOTARY PUBLIC & JOEL BREITNER , the officer before whom the foregoing deposition was taken, do hereby certify that the witness whose testimony appears in the foregoing deposition was duly sworn by me; that the testimony of said witness was taken in shorthand and thereafter reduced to typewriting by me or under my direction; that said deposition is a true record of the testimony given by said witness; that I am neither counsel for, related to, nor employed by any of the parties to the action in which this deposition was taken; and, further, that I am not a relative or employee of any attorney or counsel employed by the parties hereto, nor financially or otherwise interested in the outcome of this action. My Commission Expires 8/14/90 UNWSSW 530 B'TOSSffl Partially 0aclas5ilied/Rel«3sed nn 3 fe^gS under provisions o( E,0 12355 by K Johnson. National Security Council UNCIASSIFIEO REPE=5ENCE SANK TRANSACTIONS Report Da ts: 1-13-3- Ccurce Tra-sact ion deference nate Bank jT.e: - 100 7 "/pe NuniDer "Oil! Numcer : A-noun- Acczu^t n; ^-OCCIBLE .-Wf-EJBI ^^1 ■:-4-2c: -.35 ealan.re; wire Deoosi'-. ?_ .000.04 5.00 DoT'j-ent r ooc.o^^.'?- 0288-" - - - ■701-{ ^^^^^^^^1 C3-01.-84 Pa lanes: 1007 wi.-s r^eDosi*- 50 .04 5.00 C oc'jiTient NumSer : 50 . 04^ . " ■ 08-13-34 Balance: 1007 Wi'-e [leoosit 100 .090.00 Doo'-ment Nunibe" : 50.045.00 0312-9 03-29-34 Balance: 1007 Wire Deoosit 150, 1 35.00 Document Number: 50.04 5.00 0312-15 10-0<5-84 Balarice : 1007 Wire Deooei!- 175 . 130.00 Document Number: 25,045.00 0307-? 10-18-94 Balance: 1007 Wire Deposit 200.225.00 Doc'jment Number : 25, 045. on 11-05-84 Balance: 1007 Wire Deposit 265.270.00 Document Number ; 65. 045. I :m 0305-8 11-19-84 Balance: 1007 Wire Deposit 300,315.00 Document Number: 35.045.00 0305- .8 12-06-84 Balance: 1007 wire Deposit 375,360.00 Document Number: 7 5,04 5.00 03U0-10 01-04-85 Balance: 1007 Wire Deposit 410.405.00 Document Nunioer : 35,045.00 02-08-85 Balance: 1007 Wire Deposit 445.450.00 Docunien t Numoer : 35.045.00 02-28-85 Balance: 1007 Wire Deposit 430.485.00 Document Number : 35.035.00 0294-20 03-26-85 Balance: 100 7 Wire Deposit 515.520.00 Documen t Number : 35,035.00 029 1 -2 J :2A.i^ - 531 MUSSIFe X 0/.49 BANK REFERENCE TRANCAOriONC i^eport Date : .-i:-37 Source Transaction -vpe Reference Numoer Am' ount 04-26-85 100- ^1.-= Deposit 550. 555.. .0 Oocun.enr NuniCer : 35.035.'iO 32^y-3i 05-21-85 100- 6a 1 area : Wire CeooEi' Document Numoer : 25. 035. CO 0"" -03-85 i:.24 Balance : ^■. re Depos: : &00,635.00 Document NumDer : 25.045.00 :ii9-7 Account Name: ^^| 1 (8004) 03-05-36 1024 Balance : Ohecu 37.418.CCCR Document Number: 37.418.00CR Q120-1 04 -01-80 1024 Balance: OhecU 120,736.C0CR document Number: 33.366 ...OCR 0117-1 Account Name: H| (3005) 08-09-34 130? 8alance: Oeposi t 2.300.00 111 Document Number: (8007) 106 Document Number: 2. 300.00 03 12-? Account Name: ^^| 07-11-34 1007 Balance : Deposi t 4.000.00 4,000.u0 0318-3 -cccunt Name: ^H HH^H 08-27-85 1024 Balance : Deposi t 4.093.00 113 Document Number: 4 . 093 . 00 0152-23 Account Name: ^^H HHP 08-26-85 1024 Balance: Deposit 7,500.00 120 Document Number: • .500.00 0152-33 Account Name: DHL (8014) 07-10-85 1024 Balance: Deposi t 29.95 101 Document Number: 29.^5 01b9-4i mmm 532 BNCIASW /C fto^^. f<.y Agosto 10, 1994 n\^ Muy senores nuestros: Por medio de la presente les autorizamos a debitar nuestra cuenta <=°'^^^^"^€^^^H^H||^|^H 1<3 <^s USS50,000.00 para que se sirvan efectuar la siguiente trans- ferencia: a) ^^^HBQ|H|HHHM| Partially Declassified/Released on 3 f-^^ 6 8 under Ofovlsions ot E 12356 by K Johnson. National Security Council iffiUSSIflEO 533 lINOUSSIflED ;jf /^i^^^y ']\^ Agosto 28, 1984 Present Muy senores nuestros: Por medio de La presente les autorizanos a debitar nuestra cuen- ta corriente^^^^^^^^HH la cantidad de US$50,000.00 para
que se siryan efectuar la siguiente transferencia:
ily Declassified/Released on 3i^B& 'R
under provisions 0fE0l2356 vaaH^I
< Johnson, Nal/onal Secunt/ Council i F % E M '
\'
mm
534
UNCUSSIFIED
^c Jc^lfV
Julio 30, 1984
Presents.
Muy senores nuestros:
Por medio de la presents les autorizamos a debitar nuestra cuen-
±3. corriente ^^^^^^^^^^H la cantidad de USS50,000.00 para
que se sirvan efecfjar la siguiente trans ferencia:
120
b) Para crSdito de Cta. Especial U.S. Dolares No. I
Partially Deciasatied/neleased on. '" " .- •">•
undei ptovisions ol E.O 12355
^ ^-^
Partially Declassified/Released on 3A£^g8
under provisions of E,0 12356
by K Johnson, National Security Council
535
/i^ OJr^H
Preser.te.
;s r.uestros;
69^
For T^edio de la presente ^^^^^o^^^no^^i dec i ra;
tidad de 'JSS25 , 000 . 00 para que se sirvan efectuar
la siguiente transferencia :
a)
b) Para credito de
Cta. Esoecial U.S. D61ares r<o
Partially Declassified/Released on 3 fcak
under provisions of E.O 12356
by K Johnson. National Secuniy Council
536
Mssm
/<f- CJ~t
690
Octubre 18, 1994
cJ
'resente.
Muy senores nuestros:
Por medio de la presente les autorizamos a debitar
nuestra cuenta '^^'^'^isn^^'mHmHH^^H ^^ can-
la siguiente transf erencia :
b) Para credito de
Cuenta Especial U.S. D61ares #
Partially Declassified/Released on 3 /-c^R
under provisions ol E 12356
by K Johnson, National Security Council
mm\m
537
UNcussm
S^oxi <Fv
,83
Noviembre 5, 1934
Muy sefiores noestros:
Por .Tiedio de la presente les autorizamos a d ebitar
nuestra cuenta corriente^^^H^^^^m|||^|^H la can-
tidad de rjs$65, 000 . 00 para que se sirvan efectuar la siguiente transf erencia : a) b) Para credito de : Cuenta Esoecial U.S. D61ares No Partially Oeclassided/Released m3±66^ under provisions o( E 12356 by K Johnson, National Security Council 538 ONCUSSIHED /f /V^n/'f 7 67S Noviembre 19, 19S^ Presente. Estimados senores: Por medio de la preser^^ai^o^^amo^a ustedes debitar nues- tra cuenta corr iente|^^|^^^m||^^|^p la cantidad USS35,000.00 para transferirse a: 1) Banco : .2) Para pagarse a; 3) Cuenta nGmero ; c/- Partially Declassified/Released on^££^8i under pcovisions ol E 12356 by K Johnson, Nalional Security Council Cuenta Esoecial t'.S. D61ares \>^tentamente^ / UNWSSinED 539 l'5fl|| 66S Diciembre ^, 1' 'resent Estimados senores: Por medio de la present^autor^amo^a ustedes debitar nues- corrienteHmi^^^^^miH la cantidad de USS 75,000.00 para transferirse a: 1) Banco 2) Para pagarse a: Cuenta 'Especial 3) Cuenta nQmero Partially Declassitied/ReleaseO on >/-t?^ft fl lEO 12356 I Security Council under provisions c OilASSIRED 540 DNCUSSIHED V s7'^'v pr~ 564 :nero 4, 1095 Presente. Estimados senores: Por medio de la preser^^^^o^^amo^^i us tedes debitar nues- cuenta corr iented|^|^|^^|^|^| la cantidad dc US$35,000.00 para transferirse a:
1) Banco-
2) Para pagarse a:
3) Cuenta nQmero : Cuenta Esoecial Mo.
Panially Declassified/Released on 3 ^g « 8 6
under provisions o( E 12356
by K Jonnson. National Security Council
mmm
541
♦^SJ-v
HNCUSSIFO
^ ft.i^^
Febrero 8, 1935
537
Presente.
Por medio de la pres ente autorizar
tra cuenta corriente|
USS35, 000.00
a u stedes debitar nues-
56 a r
1) Banco-
2) Para pagarse a: Cuenta Especial
3) Cuenta nQmero : No.
.^6
Partially Declassified/Released on_J_£e558
undtr pfovistons of E 12356
by K Johnson. National Security Council
■M
542
ONCL/ISffD
Z^Fz.L'?^
^,
Febrero 28, 1985
519
Presente.
Por medio de la preser^^^^^o^^amo^^i ustedes debitar nues-
USS 35,000.00 p^^^tr^T^e^^^^a :
Banco : ^^^^^^^^^^^^^^^^^^^^^^^H
2) Para pagarse a:
3) Cuenta nCmero : Cuenta Especia]
Partially Declassified/Released on J/^d/SS g
under provisions ol E 0. 12356
by K Johnson. National Security Council
mmm
543
mssm
1
.".arzo 26, 1995
^9^
Por medio de la preser^^ai^or^amo^^i ustedes debitar nues-
tra cuenta corriente ||m||HHmH|^ la cantidad de
US $35, 000. p^^^tr^is^^^^s^^^ 2) Para pagarse a: Cuenta Especial Mo. 3) Cuenta nGmero : Partially Oeclassitied/Released on 3>t-iJi8S under provisions of E.O 12356 by K Johnson. National Security Council UNCLASSIFIED 544 UNCLASSIRED ^c^pRf:,-- ^ 451 .^bril 26, 19S5 'resente. Estimados senores: Por medio de la preser^^^^o^^amo^^i us tedcs debitar nues- tra cuenta corriente m^Hmmpi^m la cantidad dc US$ 35,000.00 par^^^^T^^^^^^^^
1 ) Banco
Para pagarse a: ^^^^^^^^H
3) Cuenta nQmero : Cta. Esoecial ?)oJ
Pariialiy Declassided/Released on 3(<.3 6 '&
under provisions ol E 12356
by K Johnson. National Security Council
UNCLASSIFIED
545
UNCLASSIHED
'.ayo :i, 1935
428
'resente.
Por rTiedio de la prescr^^^^o^^amo^^i us tcdcs debitor nuc
cuenta corr icn tc H|HHI^HH^H ^^ cantidad dc
USS25,OCO.OO para transferirse n:
2) Para pagarsc a
3) Cuenta nGmero : Cta. Dolares
Partially Deciassiried/Released on J/'£'S8 f>,
unaer provisions ot E 12356
by K Johnson, National Security Council
fNCUSJIflEO
82-7S2 0-88-19
546
immim
jclI b"
578
J 'J 1 1 o 3 , 19 3 5
'resente.
Por medio de la present^a^or^amo^^i ustedes debitar nues-
tra cuenta corriente |^HH||^Hm||||m|| la cantidad de
USS 25,0 0.00 para tr^^r^^^^^^^
1) Banco
for further credit to
Para pagacse ^ = ^^^^^^^^|
3) Cuenta nGmero : Cuenta Especiall
Pariiaily Declassitied/Released on J£M38
under provisions o( E 12356
Sy K Johnson, National Security Council
liNSlASSIHED
547
UNCLASSIHED
I^O^M S^
0250
I
Partially Declassified/Released on.
under provisions c
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EO 12356
Secunty Council
ONClASSIFIED^^'v • '
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ORDEN DE P4G0N0. dt otdin dt tl alsae t«l«x. 0258 pot cutniu d« por li .um, d. q <i9.9Sl.y> n / U-LOUHi-i NBtVE MIL BOVtClti'TCS KliiJir^ T OI.w -C:i . _j ( 50/100 ; y qut liquidamos y lugomos ( ^^crediundo li cuenta cornente del ( I bajo eitricu >dent><icacian 19-2-86 EJECUTADAEL , ,__. ..TC. 53.70/ ..ri^^^ Il1lirillllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllili>llililii:ii:l!:':n! 1)1111111111111 iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiinTiiliiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiTiTiiiiiiiiriiiiiiiiiiniiiiiiiiiiiiiiiiiiiiiiiiiiii iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiimiiiiiiiiiiiiniiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiuiiiiiiiu^ lllllllllllllllllllllllllllllllllllllllllllll IIIIIIIIIIIUIIIIIjllllllllllllllllllllllllll. illllHIII!l!!llli:'l COPIA CLIENTE ^■ C_,^ NOTA DE CREDITO N9 77493 icaKOlTADO m m EJECUCZON Dl NUESTBA OP 316601«/ " I Mrausa : or»j«a HTTCTt HTT. HOVrnTKHTa . CM. ui« • miem ■ u-^^riiaily Oeclassitied/Released on 3/t under D'Ovisions ot E 12356 liffiJSSIFlEO— 556 INSTRUCCIONES RECIBIDAS OE: CRZOIT £DX6SE CCJt>fE« OROEN Oi.^AGQjfjf^ d« orden de por cutnia dt pof U sumj dt aA03l892<»80796^ < E IcsnO.OOO.o/ ']/ 0fi2OI^^« M" J^/CQB OO/lpO UNCUSSIFIED No.317038 ttlcx. 0259 Y qut liquidjmoi y pigainoi ( ^icreditando la cuenta corrienie del Benaliciario No ( I baio tttncu idtntidcacion EJECUTADA EL 21-3-86 iiiiiiiiiiiiiiiiiiiiiiiiiiiliiiiiiiiiniiiiimiiiiiiimiimiiiiili iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiinrmlfflimiliiirfi iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii 4^ay^';MM^!;pi^!;i^a';:ig COPIACLIENTE NOTA DE CIUfJ)ITO N2 7752: > C R S O I T * O < EJECUCION DE NOESTRA OP .^°^'j:i'-j::rj:rr[rzjum'j& ub». Quu. cu iiiu ' xQiiooa ■ a-4 Partially Declassified/Released dn 5 /g'ygffg under provisions of E 12356 by K Johnson, NalionatSecuiUy-GoMci 10/000. 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N aljonal Secyril^ Cjiincji. 558 09-6-tt INSTRUCCIONESRECIBIOASpE; CiUEDlt 8WSSE OiatVI U 060*92'»81596./ OROEN Ogf A££y^ d« ordin dc ldta« por cutnta d« por U tum« d« pstlO.OOO.oo/ ]< UNCUSSIfi, OSDOLABiil DIZZ tOyCOa 00/100 279 tftlcz. 0261 Y qu* liquid.i Jt ¥ pjgonioi 1 Ticreditando \t cuenta corrieins del Beneficiano No. ( ) ba)0 tstncta identificacion EJECUTAOAEL 09-6-8^ T.c. 55,10 %\c 551.000,0. iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiniiiiiiiiiiiiiiiii iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii iiiiiiiiiiiiiiiiniiiiiiiiiiiiiiiiiiiiiiiii iii^^BiS;'.;r..,^M lllllllllilllllllllllllllljlllllllllllllllllllllllllllijllllllll!i::iilll!>llli COPIACLIENTE r .iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiipiiii 'liilTiiiniliinliffliinnni ifiiMiiiiiiiliiiiiiiiiiiiiiiiiiiiijKiii |M1I||||IIH !0QISI1|1WU1> |4PIH IIIMIIIIIIIIIIIIIipilllllllllllllllllillllllillh'il iilllililliiiiiiiiiiiiiiiiiiiii!:!':: iiininciiiiiiiiiiiiitiiiini!!iii!!;!im':L:" itiiiiiiiiiniiiiiinrtirTni;iTTTr!:ii!'rx':r "; H|ll'l"l|ll||ni:i|ll'i;i|i!Mn,._;;^ y. NOTA DE C31E0IT0 N2 79127 HBoa ACRCOITAOO <n w EJECUCZON D£ NUESTSA OP 318279 •/ 559 0>7-86/ UNCLASSIFIED INSTRUCCIONES RECIBIDAS 0£: ORDEN DE^i^fj^^Ua No. 318733 teXex. ^ 0262 p«i,.um.d. ^9.9ai,?0/ | ( 50/100 ) t qu« hquiditnoi y iJjjamoi ( JfferediUndo Is cuenia corrnnn del Barn ( I lM|0 tstricu ideMtidcacion EJECUTADAEL .ITC. 55,70 l!li;i!|i|!!!l!r iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiinintliliiitiiiiiiiimiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiH . iiiiiiiiiiiiiiiii!iiiiiiiiiiiiiiiiiiiiii iii!iiiiii iiii iiiiiiiiiiiiiiiiiiiii iiiiiiiiiiiiiiiiiiiiiiiiniiiniiiiiiiiiiiiiniiiiiiiiiiiiiiiiiiiiiiiiiiin ' |iiiiitiiiiiiiiiniiiiiiiiiiiiiiia^n]iuiiiji''ijiMimiiiiniiiiiiiiiiiiiiiiiniiiiiiiiiii'iiiiiiiiiiiiMn// i|i|!i||M|i|in!'|l||l|;MniFqryw!^fffffl^iri|||iiii|||l!|liM'u;uiMM|:r COPIACUIENTE f CA'' NOTA OE CIIEDITO 3060-00 N9 7957 ,CREDITADO EJECUCIONDI NUESTSA OP 318733./ 55^ Ia« OlML CO Partially Declassiliea/Releasel under provisions ol E C &y K .Jonnson. Uatonal Secuuty iC^ iClASSIFIEB 560 INSTRUCCIONES RECIBIDAS OE: ORDEN DE PAGO No. d.ord«ndt EL MISMO lUZH 2S6>e6 CP.EDIT SUISSE GENEVE^ 0822-9250-137/6 UHCUSSim No. 319559 TZLIX ^ 0261 por cutnta dt »or la luma dt KO.CCC. 00/ I \ tOLARZCiVElKTE MIL^aN CC/lCC-x-x- I qua liquidamoi v pagamot ( ^^crtdiundo la cuenta cornenta del Benaficiano I 1 I bajo astncia identilicacibn Firma dalloil bcneln EJECUTAOA EL 25-8-86 Tc. 56.30 » Jei>i26.oo o.ooy| •"^^V:^^'":.^;;;:.?;'^"''' olon.ajCin minon clento^ ''•^^^^^•^■/"litLHflfflfTllllt^^M^iTirifRmilllllllllillllllllllilillllllllll lilulllllfll Hiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii:i;iiiiiiiiiiiiii!iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii!iiii iiiiiiiiliiiiiiiiiiiiiiiiliiiiiiiiiiiiiiiiiiliiiiiiiiiiiiiiiiiiiiiiimiiiiiiiiiiiiiiiilii COPIACLIENTE iiniiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii!! iiiililiiiiiiiliilliiiillliiiiliiniiiiiiiniii iiiiiiiiiiniiiiiiniiii!iiiii!iii'iiiiiii:!':ii iiiiiiiiMiiiiiimiw«;wwHf'tii!Unii- NOTA ne CREDITO xxxxx 306000 N2 79532 iCREOITAOO to: EJECUCIGN DE OP Nt319559 VEINTE MIL CON OO/100-x-X' CUENTA N llMt C*l ]ll«a KDlllXM 13 U Partially Declassified/Released nn 3 f(:&'. under provisions ot E 12356 by K Johnson, National Security Council. NCLCTOr 561 Ali.or Ji INSTRUCCIONES RECIBIOAS-OE 08-9-86 TO CBLOIX i^UiH GU^ OROEN OE PAGO No. 2*090592501316./ d« ofd«n d« •! "iMW por cu«ntj d« *»•■• / fTTTTTZ^ n / 0:-DOLAa:Jl DIIX WL COS 00/100 I os<io.ooc,oo/ I \ y por la sums dt > qut liquidamoi y (xjamot (*¥jcrediljndo Ij cusnta corn ( ) b4|0 titncu idaniificacion „.„. 9-9-66 / .iTc 56.65/ %|c 566. 500.00/ EJECUTADAEL colones ; qulniBTitoaT^ IIIIIIIIIIIIIIIIIIIIIIHIIIIIIIIIIIIIIIIIIIlfilllllllllllllllllll iiiiiiiiiliiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiniiiiiiiiiiiiiiiiiMiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiliiiiiiiniiliiiiiilliiiiiiiilllii iij.ii;nH..!iii!iiiiiiniiii!:iiiiiiiiiiiiiiiiiiiiiiii 'iiiiiiiiii '"'iiaiiiliM^lil^' n;iiiiiiiiiini!iiiiinnrrwTif|^riiTigfff|ii iiilliiiiii iiiiiiini iiiiiiiii!: COPIACLIENTE NOTA DE CREDITO xxxx 306000 N2 79592 CBEOITADO an M EJECUCION DE OP N« 31 9802 PartiaHy Oeclassitied/Released on 3 fe^(g 8 under orovisions of E 12356 by K Jotinson. National Security Council 562 07-ao-8^ IINCUSSIFIED No, 320273 STRUCCIONESRECIBIOASDE: . CglOXt BUlStZ OUiCVJ VIZ u .om. d. I 03110.000,0)9 I (^ 0-DOUIRE2 1 DIE* WL CO! 00/100/ vi« liquidamot y pigamoi ( ^citdiundo \* cutnta cornentt del B«ne; ( ) tM|0 eitricia identificacibn > V ^69.000.0/- 56,90-^ lllllllllllllllllilillllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllll iiiiiiii!iiiniiiiiiiiiiiiiii!iiiiiiiiiiiiiiiiiiiiiiiiiii1iiiliiiiniiiiiiiiiiiiuffiMi llllllllllllllll telox. X 0265 ^PIACLIENTE lililiilillilii!!"!;;:'. 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N? »>i I NOTA UE CREDITO " N2 18958 '™^' kCBSDlT ADO m m ( 3060-00 — fartiaKy Declassified/Released on_ ofEO 12356 Security Council EJKOCIOH DI MUCBTBA OP 520728./ [)|^ "OIB ICL een 00/100 CUENTA N1 ■icussinE 564 565 UN^ASSIF'^D UNITED STATES SENATE SELECT COMMITTEE ON SECRET MILITARY ASSISTANCE TO IRAN AND THE NICARAGUAN OPPOSITION DEPOSITION OF GLENN A. ROBINETTE Washington, D.C. Friday, March 27, 1987 Deposition of GLENN A. ROBINETTE, called for examination by the Senate Select Coinmittee on Secret Military Assistance to Iran and the Nicaraguan Opposition, at the Senate Hart Office Building, Room 901, at 10:30 a.m., before DAVID L. HOFFMAN, a Notary Public within and for the District of Columbia, when were present: JOHN D. SAXON, ESQUIRE Associate Counsel Senate Select Committee Hart Senate Office Building Room SH-901 Washington, D.C. 20510 On behalf of the Committee. MARK H. TUOHEY, III, ESQUIRE Attorney at Law ,e^x-, »•> Pierson, Ball & Dowd ^'' . - D?-la3!if;H/ Release' on J.8££iiL 1200 18th Street, N.w. jnder p rovisvjr^ of Lj '2?^^ Washington, D.C. 20036 by •■B^, Natiof.:.. oecurit, Council E-rcDCWU. tEPOriTEns mc UfRUKSIlPlED 566 UNOl^Sy^UD TABLE OF CONTENTS 'i Glenn A. Robinette !| By Mr, Saxon tCC-rCMIItL l«CPO«Tt«S INC EXAMINATION IDENTIFIED 11 12 12 13 19 UN(MSSM'fED 567 UMCUSSIfftO •CE^CDCML «tPO«TE«S IKC Whereupon, GLENN A. ROBINETTE was called as a witness and, having been first duly sworn, was examined and testified as follows: EXAMINATION BY MR. SAXON: Q Mr. Robinette, would you state for the record, please, your full name. A Glenn A. Robinette. Q Your address, sir. A 3265 Arcadia Place, N.W., Washington, D.C. Q Could you tell us by whom you are employed, sir. A I am self-employed. Q What would be the name of the entity under which you do business? A Glenn Robinette & Associates. Q What is your business address? A The same as the home address . Q What is the nature of the business that Glenn Robinette & Associates engages in? A I do security consulting, consulting on security UitS^I(S^j?^E3 568 UNCkftSSAHiD ltCl-flOt»U. DEPOHTEIIS INC type projects. Q Could you elaborate a bit on that? A Yes. Individuals, businesses or companies require advice and guidance on physical security, personal security, technical security. Q Okay. Do you or did you ever have any relatives who worked for the Federal Bureau of Investigation? A No, I did not. MR. TUOHEY: Off the recrod, (Discussion off the record.) BY MR. SAXON: Q Mr. Robinette, I'd like to inquire into matter which has received some public notice within the last few weeks involving a security system installed at the home of LTCOL Oliver North. First question, do you, sir, know LTCOL Oliver North? MR. TUOHEY: I object to the question on the grounds of privilege, and I instruct my client not to answer. Now, you can leave this on — you can leave it on the record. How is it best handled for you? MR. SAXON: I do not care whether you assert ijNetfts^i^^i^ UNeiASStPtED !l Ijprivilege on behalf of your client. I see no reason to go 1 through the process of having him do it. I would, however, ^like to ask the questions which I would have otherwise asked. — MR. TUOHEY: Fine. MR. SAXON: — for purposes of ascertaining where privilege does and does not apply. MR. TUOHEY: Why don't we do this then, to make it I simple. I will just say we assert the privilege in response to the question, or do you want me to object? Whichever is easiest. It is going to be a transcript for the Committee. I Will object and assert the privilege. MR. SAXON: Okay, BY MR. SAXON: Q Have you ever met Colonel North? MR. TUOHEY: Object to the question; assert the privilege. BY MR. SAXON: Q Have you ever done any work for Colonel North? MR, TUOHEY: Object to the question; assert the privilege. BY MR. SAXON: Q Have you ever done any work on behalf of or as a yN0ift^|J?3 570 UM€tftSStBt9 favor to Colonel North? MR. TUOHEY: Object to the question; assert the privilege. BY MR. SAXON: Q Have you ever had a conversation with Richard Secord? Did you have a conversation with Richard Secord sometime in the time frame of late spring or early summer 1986 regarding Colonel Oliver North? MR. TUOHEY: Same objection. BY MR. SAXON: Q Have you ever spoken with a Mr. Ben Chatham of Automatic Door Specialists? MR. TUOHEY: Same objection. MR. SAXON: That objection would be as to any conversation of any nature? MR. TUOHEY: Yes. Yes, it would, although, it would make it easier for my client and I to respond, John, if you are going to go beyond the time frame at issue , which I guess, based on what's public, a matter of public record, the period of 1986 through the present — if your question is, have you ever had a conversation of any kind with an individual other than during this period, we might have a >CI'fEDCIML I1EI><J«T€«S, INC Uifl6|EASStFtcD 571 UNeiftS^FlED different response. BY MR. SAXON: Q Have you ever had a conversation with Mr. Ben Chatham of Automatic Door Specialists about doing any work for Colonel North? MR. TUOHEY: Object to the question and assert the privilege. BY MR. SAXON: Q Have you ever had any conversation with Mr. Chatham! regarding doing any work for an associate who press reports suggest — an associate of yours whom press reports suggest would have been Colonel North? MR. TUOHEY: Object to the question; assert the privilege. BY MR. SAXON: Q Have you ever had a conversation with Mr. Chatham regarding doing any work to install a security system at 703 Kentland Drive, Great Falls, Virginia? MR. TUOHEY; Object to the question; assert the privilege. BY MR. SAXON: Q Have you ever been to 703 Kentland Drive, Great UNGL^Stf^ED 572 uNe^)ts^r;i3 Falls, Virginia? MR. TUOHEY: Object to the question; assert the privilege. BY MR. SAXON: Q Do you know, sir, who lives at 703 Kentland Drive, Great Falls, Virginia? A MR. TUOHEY: Same question. BY MR. SAXON: Q Have you ever met Mr. Chatham at a private home, a private residence for a job that Automatic Door Specialists was to do? MR. TUOHEY: Other than what has been previously described? MR. SAXON: That's correct. MR. TUOHEY: Other than the address you've just given or including? MR. SAXON: Including. MR. TUOHEY: Object to the question and assert the privilege. BY MR. SAXON: Q Have you ever told Mr. Chatham that a party living at 703 Kentland Drive was an associate of yours? uNei^sffitd Kl-nOiHtL DEPOIITEIIS 573 UHCll^SSiiltO MR. TUOHEY: Object to the question; assert the privilege. BY MR. SAXON: Q Did you ever receive an invoice from Automatic Door Specialists for a job done at 703 Kentland Drive, Great Falls, Virginia? MR. TUOHEY: Object to the question; assert the privilege. BY MR. SAXON: Q Did you ever call Mr. Ben Chatham of Automatic Door Specialists upon receipt of an invoice and ask him to meet you for dinner? MR. TUOHEY: Same objection. BY MR. SAXON: Q Did you, in fact, ever meet Mr. Chatham for dinner at a Japanese restaurant in Silver Spring, Maryland, or, for that matter, in any other restaurant? MR. TUOHEY: Same objection. BY MR. SAXON: Q Did you, over dinner with Mr. Ben Chatham at a restaurant in Silver Spring, Maryland, present him an envelope with cash in the amount of$2173?
UH€Lft$^RED 574 UN6tll[SSIFA^3 MR. TUOHEY: Sarae objection. BY MR. SAXON: Q Have you ever called Mr. Chatham of Automatic Door Specialists with regard to servicing a home security system, gate intercom at 703 Kentland Drive at Great Falls, Virginia, after such time as the system was installed? MR. TUOHEY: Same objection. BY MR. SAXON: Q Have you ever discussed with Mr. Chatham, apart from the job referenced in Great Falls, Virginia, doing business with him overseas? MR. TUOHEY: Same objection. BY MR. SAXON: Q Have you ever discussed with him doing business in the Far East or other parts of the world, which you are not at liberty to disclose? MR. TUOHEY: Sarae objection. BY MR. SAXON: Q Have you ever discussed with him doing business overseas involving electronic devices on buildings? MR. TUOHEY: Sarae objection. ICErEDCXL DtPOITCaS ViH£U^^?*t^ 575 UNOASS^P BY MR. SAXON: Q Have you ever discussed with him doing business overseas, in which his employees would require government security clearances? MR. TUOHEY: Same objection. MR. SAXON: I would like to present to you some documents, which I would ask be marked in order as Deposition Exhibit 1, 2 and 3, and ask you to refer to, if you would, Mr. Robinette, Deposition Exhibit 1, which is a proposal submitted to Glenn Robinette & Associates by Automatic Door Specialists, presented by, if you look at the authorized signature block, Mr. Benjamin P. Chatham. This is the date of June 17, 1986, and I would ask you if you have ever seen that before. (Exhibit 1 identified.) MR. TUOHEY: On the basis of what has been previously asserted as the objection by Mr. Robinette, more specifically under the Fisher Doctrine, we respectfully decline to answer the question on the grounds of privilege. BY MR. SAXON: Q I would ask you, Mr. Robinette, if you could verify for the committee whether that is, indeed, your CI-fEOe*U. UPOtTE*! INC liN6lASS»F;ED 576 UtRHASSIFlED tCE-FEDCUl l)EK»Tt«S signature at the bottom of Exhibit 1. MR. TUOHEY: Same objection as just made. BY MR. SAXON: Q I would ask that you look at what has been marked as Deposition Exhibit 2, which is a letter on the letterhead of Automatic Door Specialists to Glenn Robinette & Associates, signed by Benjamin P. Chatham, dated July 7, 1986, and ask you if you have ever seen that letter before. i (Exhibit 2 identified.) ' MR. TUOHEY: Same objection. BY MR. SAXON: Q I would ask you if you have any confirmation of the facts asserted in that letter. MR. TUOHEY: Same objection. BY MR. SAXON: Q I would ask you then to look at Deposition Exhibit 3, which is an invoice from Automatic Door Specialists, Job Invoice No. 2747, billed to Glenn Robinette & Associates, and ask you if you've ever seen this invoice. (Exhibit 3 identified.) MR. TUOHEY: Same objection. uHeti^^t^ 577 UNeElfSStHED BY MR. SAXON: Q I would ask you if you have paid the amount circled on that invoice of$2173 to Automatic Door Specialists.
MR. TUOHEY: Same objection. John, are we
entitled to have a copy of this or not?
MR. SAXON: Yes. There's a copy unmarked as to
deposition exhibit number, and those are for your purposes,
and those are for you.
MR. TUOHEY: Thank you.
BY MR. SAXON:
Q Mr. Robinette, I referenced at the outset that
some of the matters I have inquired about have appeared in
public, for which reason I would like to ask you some
questions about some newspaper articles. I will give you
these as your copies to have and take with you.
The first newspaper article, which I have asked
be marked Deposition Exhibit 4, is a story from the
Washington Post of March 17, 1987, by George Lardner, Jr.,
$2,Q00 Gate." CExhibit 4 identified.) UNSEeSPlED 82-732 O-88-20 578 UNetltS^HED BY MR. SAXON: Q I would ask you first if you are familiar with, or have any knowledge of that Washington Post article. MR. TUOHEY: While I would, reflexively, based on DtPOtTCIIS INC jj the context of this deposition, assert the privilege, I want to be sure that I am doing it accurately. MR. SAXON: Do you need a moment to read the article? MR. TUOHEY: If your question is, has Mr. Robinette read the article, he can answer it. If your question is, is he familiar with the contents reflected therein, that is a different question. MR. SAXON: All right. Let me take them in order then. BY MR. SAXON: Q Mr. Robinette, you see the article in front of you. Have you read that article, sir? A Yes, I have. Q Can I ask you if there is anything in that article which you find to be inaccurate? MR. TUOHEY: Object to the question and assert the privilege. UK§ERSSI??ED 579 UNa^SflFlED ll BY MR. SAXON: Q Can I ask you, then, whether you can confirm any .1 'I of the facts stated in that article and attributed to you, !i Sir. MR. TUOHEY: Same objection. BY MR. SAXON: Q Have you, within the last month, spoken to George Lardner, Jr., of the Washington Post ? MR. TUOHEY: You may answer that question. Have you spoken to Mr. Lardner? THE WITNESS: Subsequent to this? MR. TUOHEY: No, in the last month at all, have you spoken to Mr. Lardner? THE WITNESS: Yes. BY MR. SAXON: Q Did you tell him you heard about Colonel North's security problems with "terrorists and people like that" in a Northern Virginia bar one evjning? MR. TUOHEY: Object to the question and assert the privilege, and I will object emd assert the privilege to each and every question regarding the contents of the interview, although you can ask them, John. IjNgkftS^iF^ED 580 UNClASSlf^D Kci-ttottAi. UK»iin. INC BY MR. SAXON: Q Did you tell Mr. Lardner that Richard Secord told ;' you of Oliver North's difficulties, after Colonel North was ii ij publicly linked to aid for the contras? MR. TUOHEY: Same objection. BY MR. SAXON: Q Did you tell Mr. Lardner that you were a "security consultant"? MR. TUOHEY: Same objection. BY MR. SAXON: Q Did you tell Mr. Lardner, 'General Secord told me to talk to him," meaming Colonel North? Continuing the quotation, "I think there had been some things put in the mailbox, potential explosives. And there was also some concern about cars driving onto the property." MR. TUOHEY: Same objection. BY MR. SAXON: Q Did you tell Mr. Lardner that the bill for this job was "around$2,000"?
MR. TUOHEY: Same objection.
BY MR. SAXON:
Q Did you tell Mr. Leurdner that you paid for that
UNeEltSS'i^'iD
581
UHCl^Stf^^^
bill upon receipt of the invoice, in cash?
MR. TUOHEY: Same objection.
BY MR. SAXON:
Q Did you tell Mr. Lardner, "I considered it worth
it as perhaps a business venture"?
MR. TUOHEY: Same objection.
BY MR. SAXON:
Q Did you tell Mr. Lardner, that you hoped Colonel
MR. TUOHEY: Same objection.
BY MR. SAXON:
Q Did you tell Mr. Lardner — excuse me. Did you
suggest to a reporter that you had in mind putting in more
gates for North's friends and neighbors?
MR. TUOHEY: Same objection.
BY MR. SAXON:
Q Did you tell Mr. Lardner, you did not regard
paying for the gate in cash as "a very unusual deal. I
pay in cash for a lot of things"?
MR. TUOHEY: Same objection?
BY MR. SAXON:
Q Did you tell Mr. Lardner that you still expected
UNCtftssyr.Eo
582
UHefPSSfFED
expected Colonel North to pay you back one day?
MR- TUOHEY: Same objection.
BY MR. SAXON:
Q Did you tell Mr. Lardner of Colonel North, "He'll
pay. I look at it as simple business. He's a hell of a nice
guy.
Very nice family. Super kids. He just wasn't able
aCCfEOMU KCroHTEIIS
to come up with the money"?
MR. TUOHEY: Same objection.
BY MR. SAXON:
Q Did you tell Mr. Lardner that you met General
Secord through Thomas G. Clines?
MR. TUOHEY: Same objection.
BY MR. SAXON:
Q Did you tell Mr. Lardner that you have known
Thomas G. Clines for than 30 years?
MR. TUOHEY: Same objection.
BY MR. SAXON:
Q Did you tell Mr. Lardner, of our committee, "They
must think I've been moving money"?
MR. TUOHEY: Same objection.
MR. SAXON: I'd like to invite your attention and
that of your counsel to Deposition Exhibit No. 5, which is
b?KtflS$irED 583 UNeiRSS«FtEO a newspaper article in the Chicago Tribune on the date of March 18, 1987, by Mr. Michael Tackett and William Gaines, with the headline, "North Financial Aid Arranged by Secord. (Exhibit 5 identified.) BY MR. SAXON: Q I would ask you, sir, whether you have read that article before. MR. TUOHEY: Have you read it? THE WITNESS: Yes, recently. BY MR. SAXON: Q Thamk you. Did you ever talk with either Mr. Tackett or Mr. Gaines? A Yes. Q Could you tell us which? Mr. Tackett? A Yes. Mr. Tackett. Q Mr. Gaines? A No. Q So you talked only with Mr. Tackett. Did you ever tell Mr. Tackett that you paid$2000 cash to a contractor to install a security system
for Colonel North?
UN€t«SSr,ED
584
UNC^I^tHED
MR. TUOHEY: Same objection.
BY MR. SAXON:
Q Did you tell Mr. Tackett that you have billed
North for work but have not been paid?
MR. TUOHEY: Same objection.
BY MR. SAXON:
Q Could you tell us when you billed Colonel North?
MR. TUOHEY: Same objection.
BY MR. SAXON:
Q Did you tell Mr. Tackett that General Secord
approached you last spring to the effect that Colonel
North was concerned about security and a possible terrorist
attack on his home or his person?
MR. TUOHEY: Same objection.
BY MR. SAXON:
Q Did you tell Mr. Tackett that you called North
and said you would arrange to have a security system
installed?
MR. TUOHEY: Same objection.
BY MR. SAXON:
Q Did you tell Mr. Tackett that you paid a contractor
$2000 in cash and billed Colonel North for the work? »CI-f€0€«n HtPOHIEKS unayissifcED 585 UNeiltSSfRED MR. TUOHEY: Same objection. BY MR. SAXON: Q Did you tell Mr. Tackett that Colonel North had not yet repaid you? MR. TUOHEY: Same objection. BY MR. SAXON: Q Did you tell Mr. Tackett that you were a business associate of Mr. Clines"? MR. TUOHEY; Same objection. ' BY MR. SAXON: Q Did you tell Mr. Tackett that Mr. Clines introduced you to General Secord several years ago? MR. TUOHEY: Same objection. BY MR. SAXON: Q Did you tell Mr. Tackett that you denied any impropriety in paying for the gate? MR. TUOHEY: Same objection. BY MR. SAXON: Q Did you tell Mr. Tackett that you exchanged letters with Colonel North about the debt? MR. TUOHEY: Same objection. UN{a.ftS8fflED UNOI^S^ED BY MR. SAXON: Q Did you tell Mr. Tackett that you expected to be paid by Colonel North? MR. TUOHEY: Same objection. BY MR. SAXON: Q Did you tell Mr. Tackett that Colonel North indicated in his letter to you that he was strapped for cash? MR. TUOHEY: Same objection. BY MR. SAXON: Q Have you ever received a letter from Colonel Oliver North? MR. TUOHEY: Same objection. BY MR. SAXON: Q Did you tell Mr. Tackett of the security system and its installation, "It's an innocuous thing"? MR. TUOHEY: Same objection. BY MR. SAXON: Q Did you ever tell Mr. Tackett — excuse me — "It's just a remote control gate"? MR. TUOHEY: Same objection. BY MR. SAXON: Q Did you ever tell Mr. Tackett, speaking of Uim<fi8SlfJED 587 UNOL^SfftED Colonel North, "He told rae he was really concerned about terrorists. He was concerned about his kids and all"? MR. TUOHEY: Same objection. BY MR. SAXON: Q Did you ever tell Mr. Tackett that you told North that the security gate and the intercom system would help protect his family and home? MR. TUOHEY: Same objection. aY MR. SAXON: Q Did you ever tell Mr. Tackett that you believed the installation of the gate at Colonel North's home might benefit your own business. MR. TUOHEY: Same objection. aY MR. SAXON: Q Did you ever tell him, "I was hoping to get more business. He volunteered if I wanted that if I wanted to use the gate as a reference for other business, he wouldn't mind"? MR. TUOHEY: Same objection. BY MR. SAXON: Q Did you ever tell Mr. Tackett that Secord approached you about helping Colonel North? ICtftOtHAL ItWtTEIS mC UN€ift^fik:D 588 UNtUS^HED BY MR. SAXON: Q Did you ever tell Mr. Tackett, "Secord said here's the phone number. Call him up," meaning Colonel North? MR. TUOHEY: Same objection. BY MR. SAXON: Q Did you ever tell Mr. Tackett that after the gate was installed. Colonel North wrote you a letter thanking you for your concern for his family? i MR. TUOHEY: Same objection. BY MR. SAXON: Q Did you ever tell Mr. Tackett that you had no other business dealings with Richard Secord? MR. TUOHEY: Same objection. BY MR. SAXON: Q Did you tell Mr. Tackett that you and Thomas Clines had been business partners in several business ventures in conjunction with one of v^iich you're codefendants in a breach of contract suit on appeal before a federal appeals court in in Richmond, Virginia? MR. TUOHEY: Same objection. BY MR. SAXON: Q Can you tell us anything that you did tell *CC«0««l *CK)IIT»S INC UmSkASS^HEO 589 UlAaASSirSED Mr. Tackett in the conversation which you have previously acknowledged? MR. TUOMEY: Same objection. BY MR. SAXON: Q Can you tell us anything that you told to Mr. Lardner in the earlier conversation you've acknowledged? MR. TUOHEY: Same objection. BY MR. SAXON: Q Mr. Robinette, were you ever employed by the Central Intelligence Agency? MR, TUOHEY: You may answer that. THE WITNESS: Yes, I was. BY MR. SAXON: Q Could you tell us the approximate dates of your employment? A 1951-1971. Q Cein you tell us the nature of your work for the agency? MR. TUOHEY: John, I'm going to object, not on the grounds of self-incrimination privilege, but on the grounds that Mr. Robinette, when he retired from the Central Intelligence Agency, signed an agreement that he would never UH^ASSii 590 UmilASSIFIED disclose the details of his employment. I can formalize that in a national security type assertion, but for the moment, I am going to instruct the client not to answer the question. MR. SAXON: Let me say for the record, that this a cleared deposition. Our court reporter is cleared at the secret level. I am cleared at top secret and compartmented information. Whether that assists you in revising your previous answer, I don't know. MR. TUOHEY: It does not assist me today. It may assist me at a further discussion down the road, and I would have to review the terms of that agreement before I advised my client. MR, SAXON: Okay. BY MR. SAXON: Q If you can't describe the exact nature of your work for the agency, could you state for the record your position or title at the CIA for any or all of your positions? MR. TUOHEY: I believe the same objection would apply at this point. I will review the agreement, the security agreement that was signed by my client, and at a future date, maybe we will be able to discuss this, but for tci-fcociuu. •CPOireiis U^ASS^flED 591 UN^ItSSIFltD the moment, I am going to have to instruct him to respectfully decline to 2mswer the question. BY MR. SAXON: Q Are you now employed by the Central Intelligence Agency? A No, I'm not. Q Have you been employed by the agency since leaving in 1971? I MR. TUOHEY: I instruct the witness not to answer ! the question on the grounds of privilege. MR. SAXON: Privilege as to security? MR. TUOHEY: Yes. MR. SAXON: That objection would likewise apply to the question: have you ever done any work on a contract basis for the agency, since leaving in 1971? MR. TUOHEY: Same objection. BY MR. SAXON: Q Have you ever done 2my work as a security consultant for the United States Capitol? MR. TUOHEY: You may answer. THE WITNESS; No. itroiiTiiis IMC UNfikftS^JflED 592 UNCiA&SlEIED BY MR. SAXON: Q Have you ever done any work as a security consultant at the White House? A No, I have not. Q Have you ever done any work as a security consultant, after leaving the agency in or for clients in South Africa or doing work in South Africa? A No, I have not. Q The same question as to the Middle East. MR, TUOHEY: I an going to instruct my client not to answer the question, on the grounds of his Fifth Amendment, privilege. BY MR. SAXON: Q The same question as to the State of California. MR, TUOHEY: As to all client questions, since his retirement from the CIA --well, I will listen to each one, but as to California, while that's very general, and I admit that to you, it's very general, I am going to err on the side of caution and advise him not to answer the question, on the grounds of privilege. BY MR. SAXON: Q Have you ever done any work, since retiring from «C£^EO£«»L ItPOITEHS UKtl^SSlfltB 593 UN(n.ASSIFt£D tcE-rcoMAL nnmtn mc the CIA, security work, on the premises of or involving aircraft hangars? MR. TUOHEY: I am going to object to the question and instruct ray client not to answer. BY MR. SAXON: Q Have you done any work as a security consultant involving security fences? MR. TUOHEY: Same objection. BY MR. SAXON: Q Have you done any work as a security consultant involving radar devices, in general? MR. TUOHEY: Same objection. BY MR. SAXON: Q A specific question, as to Central America. KR, TUOHEY: Same objection. BY MR. SAXON: Q The same question regarding nuclear power plant security in South Korea. MR. TUOHEY: You may answer that question. THE WITNESS: No. BY MR. SAXON: Q Have you ever had any involvement with a business UNSL^SH^iED 594 UNetftSSIHED entity entitled EATSCO? MR. TUOHEY: I object to the question and instruct my client not to answer. MR. SAXON: On what basis? MR. TUOHEY: Fifth Amendment. BY MR. SAXON: Q Have you ever been interviewed by law enforcement authorities or authorities within the criminal justice system at either the state or federal level, to include prosecutors, with regard to EATSCO? MR.- TUOHEY: May I consult my client? MR. SAXON: Yes. (Discussion off the record.) MR. TUOHEY: The question is whether he was ever interviewed by a law enforcement official of any type with respect to EATSCO? MR. SAXON: That's correct. M1^, TUOHEY: I'm going to instruct ray client not to ftnswex the question on the grounds of privilege. BY MR. SAXON: Q Let me narrow it then and ask whether you've ever been interviewed by authorities regarding EATSCO, who are at UMSfeASSaJHED «CI-fEO€«»l «EPO«TE«S INC 595 UNeE/(SS(PlED the state level? MR. TUOHEY: Same objection. BY MR. SAXON: Q Same question as to federal law enforcement authorities. MR. TUOHEY: Same objection. RY MR. SAXON: Q Have you ever testified before a grand jury ! investigating matters involving EATSCO? MR. TUOHEY: You can answer that question. THE WITNESS: Yes. BY MR. SAXON: Q Can you tell us whether that was a federal or state grand jury? MR. TUOHEY: Do you know? THE WITNESS: I don't know. I know where it was. BY MR. SAXON: Q Cam you tell us that? A Virginia. Alexandria, Virginia. Q Northern Virginia? A Yes. Can you tell us anything a±iout the nature of that iccrcocui acKiaTC*: mc UiS^Ul^S^iED 596 UNd'ftSSffltO testimony. ICI-rCMUl «tPO«TEIIS IKC MR. TUOHEY; I'm going to object to the question on the grounds of privilege. BY MR. SAXON: Q Could you tell us the approximate date of that testimony before the grand jury in Alexandria, Virginia? MR. TUOHEY: You may answer the question. THE WITNESS: The reason I'm acting vague, is damn -- that ^- I'm going to guess, subject to ray trying to scratch my' head — with records — '82 or '83. I cim sure it's a matter of record. It seemed to me it was hot. BY MR. SAXON: Q Thank you. Do you know an individual named Thomas G. Clines? MR. TUOHEY: Object to the question on the grounds of privilege and instruct the witness not to answer. BY MR. SAXON: Q Have you ever done work for Mr. Clines. MR. TUOHEY: Same objection. BY MR. SAXON: Q Are you familiar with Systems Services International. Inc? UNCuasyiJED 597 UMCtRSSfftO MR. TUOHEY: Same objection. BY MR. SAXON: Q Do you have knowledge of Systems Services International, Inc. paying a fine in 1984 in the amount of 5100,000? MR. TUOHEY: Same objection. BY MR. SAXON: Q Have you ever been involved with a business arreuigement , whether totally private or on behalf of an entity or agency of the United States Government to sell arms to Mr. Somoza in Nicaragua? MR. TUOHEY: Same objection. BY MR. SAXON: Q Do you know Erik von Marbaden? MR. TUOHEY: Same objection. HY MR. SAXON: Q Have you ever worked for or with Mr. von Marbaden? MR, TUOHEY f Same objection. BY MR. SAXON; Q Do you know John Sinlaub? MR. TUOHEY: You may answer that. THE WITNESS: No. li^J^S^^s'^^ Cf-rCMtU XPOITEIS INC UNCiAS^lF^D BY MR. SAXON: Do you know Robert Dutton? MR. TUOHEY: Same objection. BY MR. SAXON: Have you ever worked for or with Mr. Dutton? MR. TUOHEY: Same objection. BY MR. SAXON: Do you know Richard Gad? MR. TUOHEY: You may answer that. THE WITNESS: No. BY MR. SAXON: Do you know Albert Hakim? MR. TUOHEY: Same objection. BY MR. SAXON: Have you ever worked for or with Mr. Hakim? MR. TUOHEY: Same objection. BY MR. SAXON: Do you know Robert Owen? MR, TUOHEY; Same objection. m. SAXON; Have you ever worked for or with Mr. Owen? MR. TUOHEY: Same objection. U^flSSlf!ED 599 UNCEH^^llD BY MR. SAXON: Do you know Richard Secord? MR. TUOHEY: Same objection. BY MR. SAXON: Have you ever worked for or with Mr. Secord? MR. TUOHEY: Same objection. BY MR. SAXON: Do you know Robert Lilac? MR. TUOHEY; Same objection. at MR. SAXON: Have you worked for or with or met Mr. Lilac? MR. TUOHEY: Same objection. BY MR. SAXON: Do you know Theodore Shackley? MR. TUOHEY; Same objection. BY MR. SAXON: Have you ever worked for or with Mr. Shackley? MH. TUOHEY: Same objection. BY MR. SAXON: Do you know Rafael Quintero? MR. TUOHEY; Same objection. aCE-fCOUM. nCPQITEIIS mc UK€tftSi^lf}E3 600 UHClftSSIFftO BY MR. SAXON: Q Have you ever worked for or with Mr. Quintero? MR. TUOHEY: Same objection. BY MR. SAXON: Q Do you know Carl Channel? MR. TUOHEY: Same objection. BY MR. SAXON: Q Have you ever worked for or with Mr. Channel? MR, TUOHEY: Same objection. BY MR. SAXON: Q Do you know Mr. Felix Rodriguez, also known as MeLx Gomez? MR. TUOHEY: Same objection. BY MR. SAXON: Q Have you ever worked with Mr. Rodriguez, either with or for hin> under that name or that of Mr. Gomez? HR, TUOHEY; Same objection. BY MR. SAXON; Q Do you know Mr. Richard Miller? MR. TUOHEY: Same objection. BY MR. SAXON t Q Haye you ever worked for or with Mr. Miller? UHSIJ§§\?'^' tCI-rCDCMU. HEKITEHS 601 UNa^SHlED MR. TUOHEY: Same objection. BY MR. SAXON: Q Do you have any knowledge you have gained, other than from general news accounts, regarding activities on hehalf of the United States within the period from 1981 to present, to sell, transport or ship arms, directly or indirectly to Iran? MR. TUOHEY: Same objection. ; BY MR. SAXON: | Q Do you have any independent knowledge gained separate and apart from press accounts, dating to roughly late November 1986, regarding efforts to supply arms, ammunition or other military equipment to the opposition forces in Nicaragua, otherwise known as the contras? MR. TUOHEY: Same objection. BY MR. SAXON: Q Do you have any independent knowledge, other than that gained from general news accounts since the post-Novembei '86 period regarding efforts to divert money from the profits gained from the sale of arms to Iran to the opposition forces in Nicaragua, otherwise commonly known as the contras? MR. TUOHEY: Same objection. ACI^EDCtU •troiTt«S INC UKil^ll^^^JED 602 UNDI^SH'IED BY MR. SAXON: Q Do yoa have any independent knowledge, gained apart from general news- accounts; regarding American hostages held in Lebanon? MR. TUOHEY: You may answer that question. THE WITNESS: Would you say that again, please? I'm listening closely, but I miss. BY MR, SAXON: , Q If I need to restate it fiirther, just tell me. I Do you have any knowledge, independent of general news accounts regarding American hostages held in Lebanon? A No , I don ' t . Q Do you have any knowledge — excuse me. Let me rephrase that. Have you ever worked for or with Global American Resources? MR. TUOHEY: Same objection. BY MR. SAXON: Q Have you ever worked for or with Transworld Arms, Inc.? MR. TUOHEY: Same objection. UNetftSS^F5E0 UK^li'^SR^''- BY MR. SAXON: Q Have you ever worked for or with Edwin Wilson? MR. TUOHEY: Same objection. Well, let me just say this for the record. Mr. Wilson and Mr. Robinette were in the Central Intelligence Agency during some of the same years. My client, in response to your question, would testify that he has met Mr. Wilson, has never had any professional dealings with him, has never worked on any project in or out of the Central Intelligence Agency with him, but if he saw him in a room, would he know who he was, yes. But he's had no relationship. And since that name has special character in this city, given his activities and criminal involvement, I want my client to answer those questions directly without an assertion of privilege. So you may ask anything you like about Mr. Wilson. BY MR. SAXON: Q Do you know Mr. Edwin Wilson? A Yes, I do, Q Apart from the period of your employment at the Central Intelligence Agency, have you ever worked for Mr. Wilson? No, I have not. U Hf^JlS«'« 604 UNClASSimD Q You never swept an office for Mr. Wilson in Washington, D.C.? A To ray recollection, no. I had been requested. That was one of the things he asked me. I was trying to reraember. I did an adjoining suite. Would that have been on K Street in Washington, D.C.? A Uh-huh. Q Would that have been at the request of Mr. Wilson? A 1 doubt it. I dealt directly with the principal who occupied, it, an entirely different compamy. Q So if I understand your testimony, you never swept an office owned, used or rented by Mr. Wilson, immediately after federal authorities had entered into his suite and engaged in activities which led Mr. Wilson to believe that they might have bugged his office? A No, sir. But I can recall him asking me to do that. And it might have been at that breakfast up at the Dniyersity Club. I may be wrong on that, but it's a long time ago, but no, sir. Q Have you ever rented a space from Mr. Wilson? A No. tCC-rCOCML «CfO«Tt«S INC UN£tftS^lriED 605 UKCLISt^r^tD tCI-flMliU. •fro«TC>S iHZ Q Have you ever done contract work for Mr. Wilson? ^j A No . il Q With regard to all previous questions asking whether || you have done work for Mr. Wilson, have you also ever done ij work for amy businesses which he owned or was associated with? ij A No . Q Have you ever swept offices which were for corporations owned or associated with Mr. Wilson? A Not to my knowledge. Q Have you ever worked for or with Udall Corporation?' MR. TUOHEY: Object to the question. I instruct the witness not to answer on ground of privilege. BY MR. SAXON: Q Have you ever worked for or with Udall Research Corporation? MR. TUOHEY: Seuoe objection. BY MR. SAXON: Q Have you ever worked for or with Udall Resources, Inc., S.A.? MR. TUOHEY: Same objection. BY MR, SAXON; Q Have you ever worked for or with Systems Services li»;HASSV5£^ 606 UNdftS^ft^tD II International? . ^ ' MR. TUOHEY: Same objection. BY MR. SAXON: •CKWTCIIS INC I Q Do you have any knowledge, independent of general I news accounts, of Project Democracy? MR. TUOHEY: Same objection. BY MR. SAXON: Q Have you ever worked for or with Corporate Air Services? MR. TUOHEY: Same objection. BY MR. SAXON; Q Have you ever worked for or with Intercontinental Technology? MR. TUOHEY: Same objection. BY MR. SAXON: Q Have you ever worked for or with IBC? MR. TUOHEY: Same objection, ay MR, SAXON: Q Har/e you ever worked for or with Stanford Technology Corporation? MR. TUOHEY: Same objection. ^set<\^'^^^^' 607 SA^CON: BY MR. SA^CON Q Have you ever worked for or with Lake Resources? MR. TUOHEY: Same objection. BY MR. SAXON: Q Have you ever worked for or with Southern Air Transport? MR. TUOHEY: Same objection. BY MR. SAXON: Q Did Thomas Clines ever employ you in any way, in order to help incriminate Edwin Wilson? MR. TUOHEY: Same objection. Can we just finish one thing (Discussion off the record.) THE WITNESS: Would you say it again? I am certain of my answer, but I want to be sure I understood your question. BY MR. SAXON: Q I apologize for an unintentionally vague question. A It sounds clear, but it sounds odd. Q Have you ever been employed by or worked for or with Thomas G. Clines in an capacity in which he instructed you, suggested to you or importuned you to, in any way. UN£l6S^^r«£0 KE-rCOCIiU. aCKITEHS INC UHa%SS1?^^ ME-FEMIUU. «CPa>TCIIS incriminate Edwin Wilson?' A No. Q Do you know a woman by the name of Charlene Brill? A Yes. Q Can you tell us how you came to know her? MR. TUOHEY: Object to the question on the grounds of privilege; instruct the witness not to answer. BY MR. SAXON: j Q Can you tell us for what period of time you've | known Ms. Brill? MR. TUOHEY: Same objection. MR. SAXON: That would be the objection under the Fifth Amendment privilege 2uid not going to security? MR. TUOHEY: Yes. BY MR. SAXON: Q Did you work with Ms. Brill while at the Central Intelligence Agency? MR. TUOHEY: Seune objection. MR. SAXON: I'm sorry. Which? MR. TUOHEY: Fifth Amendment. EY MR. SAXON: Q Did you ever sweep an office for Bob Gray in u»iiyvsr^*t^ 609 yjHa^SStf'^t^ Washington, D.C.? MR. TUOHEY: You may answer that. THE WITNESS: Yes. BY MR. SAXON: Q Have you given any testimony in the matters which have become known as the Iran-Contra Affair before the U.S. House of Representatives? MR. lOOHEY: You may answer that. THE WITNESS: NO. BY MR. SAXON; Q Have you been contacted by anyone employed by the U.S. House of Representatives in this matter? MR. TUOHEY; I will state for the record that a bureau agent contacted my client last evening from the Special Prosecutor's Office and encouraged him to come down and discuss matters. I have not talked to him, but my client advised the agent that he l:vet^ counsel, and that I should be contacted. There's been no contact from the House side. BY MR. SAXON: Q Do you have any documents which were requested under the Committee's subpoena of March 16, which you have US?'^tfSS ErCMDU •E'OITOS INC 610 unafissfftto brought with you today?* MR. TUOHEY: 'John, I have documents in my possession which ray client has given to me. MR. SAXON: Pertaining to matters subject to the subpoena? MR. TUOHEY: Pertaining to matters subject to the subpoena, which I have examined carefully. I have concluded that in each and every one of those documents, the Fisher Doctrine of implied self- authentication would permit me to, and I do so assert the privilege on my client's behalf with respect to those documents. BY MR. SAXON: Q So you have no documents to present to the Committee today? MR. TUOHEY: Correct. MR. SAXON: I believe that completes the questions that I would have at this time. Is there further statement that you or your client would wish to make? MR. TUOHEY: No. Other than to say, we're prepared to be present, and it is not necessary for you to issue a U|lt;^|.^S^??T:3 UC-fCMMI. lltPO«TE«S. 611 UNtWS^f^tO formal subpoena. If you will call rae, I will have my client prepared to meet any mutually convenient dates. MR. SAXON: For purposes of public testimony? Is that what we're talking about? MR. TUOHEY: Whatever. You don't need to subpoena my client from this point forward. You can call me or notify me in writing, although it is not necessary to do it in writing. I will waive any formal requirements of a subpoena. J4R, SAXON: Very good. Thank you. (Whereupon, at 11:15 a.m., the taking of the deposition was concluded.) Glenn A. Robinette U»^(^dSI'^'tO 612 CARDKCY S«curity-Sy«Jt«ms CX)RO-MATIC Automatic Doors STANLEY Parking Gat* & Fence Controls UN am 132 Washington Boulevard Laurel, Maryland 20707 Bait. 301-792-4090 Wash. 301-953-7900 Automatic Ooor Specialists SOPOSAl. SUBMiTTto rO Glenn Robfnette and Associates 966 - 5873 June 17. 1986 3365 Arcadia Place. NW Private Residence STATt »N0 :i» coot Jashinton. O.C. 20015 jOe LOCATION Kentland Drive, Great Falls, Vi •ginia Automatic Door Specialists (ADS) will automate the existing gate using an Edko Medium Duty Swing Gate Operator. To accommodate automation of gate, ADS will remove existing wooden gate post, replace it with a metal post painted white. In conjunction with automation of the gate, ADS will provide one Multi-Elmac Receiver and two Multi-Elmac Single Button Transmitters to operate gates from an automobile. ADS also will install an Aiphone Intercom consisting of an IBG-IGD Master Station inside the front door, and IBG-IHD Additional Master on the upstairs bedroom, and an IB-DA Door Station on a post outside the gate. ADS will install intercom wiring through existing conduit and will obtain power from existing box in the yard near the gate location. Quoted price doesnot include price of permits, if needed. GUARANTEE - Material & Equip. - 1 yr. Labor - 3 mo. flr l^rapOBr hereby to furnish material and latxjr — complete in accordance with above specidci ions, for the sum of Two thousand one hundred fifty-four 2,154.00 ent to ee mad« as follows 1% discount / 20 day. Net 30. A U service charge will be charged 30 days after the date of the invoice. Arrr ptanrp of ^rapoaal - rt,, aw., one. .o«.i.cat.on, ana conditions art latiiiactory ana are nereoy acceplea You are auinoruea Signalu' to do the worh as soeciied Payment j2A Q^^-^ 'Te- 5,,n.,ui ^ /^ m«nt wtil IM made «s outhnto aOc ^-"^ - 613 ^^ ^O^- A 0268 SPECIALISTS July 7, 1986 Glen Robinette and Associates 3265 Arcadia Place, NW Washington, DC 20015 Dear Mr. Robinette: Attached is an invoice for$ 2,173.00. This amount represents the
original $2.154.00 contracted for, plus$ 19.00 for an additional radio
transmitter.
Mr. Robinette', Automatic Door Specialists appreciates the business
represented by this invoice. If we may provide additional assistance to
you in the future, please do not hesitate to contact me. ^. .
_ Very truly yours,
AUTOMATIC DOOR SPECIALISTS
614
mm^^^'
ilv 27647
AUTOMATI
in WiSHIMTOH IO«(V«n
,a*>TUND 20707. 43S7
DOOR CONTtOU
SICUIITY CARDS
rARKINO OATIS
¥^^
'/-Vf7
si?
5- r.i;
615
UMCLASSlF'.tJ
CERTIFICATE OF NOTARY PUBLIC & REPORTER
I, David L. Hoffman the officer before whom
the foregoing deposition was taken, do hereby certify
that the witness whose testimony appears in the
foregoing deposition was duly sworn by me; that
the testimony of said witness was taken in shorthand
and thereafter reduced to typewriting by me or under
my direction; that said deposition is a true record
of the testimony given by said witness; that I am
neither counsel for, related to, nor employed by
any of the parties to the action in which this
deposition was taken; and, further, that I am not
a relative or employee of any attorney or counsel
employed by the parties hereto, nor financially
or otherwise interested in the outcome of this action.
ly^/
Notary Public inoij^d for the
District of C^Mimbia
My Commission Expires 6/30/90
UKClftSS)F!P?)
617
^^^r i : TR:^S(^iPi^F^RbrCEEI^
SELECT CGtSIITTEB TO INVESTIGATE COVERT
ARtlS TRAUSACTIOMS HITU IRAN
0. S. ROUSE OP REPRESENTATIVES
—and—
SELECT COIflllTTBB ON SECRET MILITARY ASSISTANCE
TO IRAN Al«) THE NICARAGUAN OPPOSITION
UNITED STATES SENATE
l^NCUSS/FI£D
Oaposltlon of GLENN A. ROBINETTB
WashingtoDf D, p.
June 17, 1987
Pages 1 thru 85
MILLER REPORTING COMPANY. INC
■ . B07 C iPt. W.1.
: WiAlnttan.D^ 20003
by a »ko, NdkMd SeJwfty^aiiAbarr-
618
UNCLASSIFIED
SELECT COMMITTEE TO INVESTIGATE COVERT
ARMS TRANSACTIONS WITH IRAN
U.S. HOUSE OF REPRESENTATIVES
and
SELECT COMMITTEE ON SECRET MILITARY ASSISTANCE
TO IRAN AND THE NICARAGUAN OPPOSITION
UNITED STATES SENATE
Washington, D.C.
Wednesday, June 17, 1987
The deposition of GLENN A. ROBINETTE, called for
examination in the above-entitled matter, pursuant to notice,
in the offices of the Senate Ethics Committee, Room 220, Hart
Senate Office Building, Washington, D.C, convened at 10:41
a.m., before Pamela Briggle, a notary public in and for the
District of Columbia, when were present on behalf of the
parties :
UNCLASSIFIED
I
619
pb2
UNCLASSIFIED
APPEARANCES:
On Behalf of the Select Committee on Secret Military
Assistance to Iran and Nicaraguan Opposition of the
United States Senate:
Deputy Chief Counsel
jtEWygT H BALLEM, S t a f f -eomrS^lT
JOHN R. MONSKY, Staff Counsel
Room 901
Hart Senate Office Building
Washington, D.C.
On Behalf of the Select Committee to Investigate Arms
Transactions with Iran of the U.S. House of
Representatives: , .i^ r P
GEORGE W. VAN CLEVE, ?n^->^-^''-*^
Room Vl-^, U.S. Capitol
House of Representatives
Washington, D.C.
On Behalf of the Witness:
MARK H. TUOHEY, III, ESQUIRE
Pierson, Ball & Dowd
1200 18th Street, N.w.
Washington, D.C.
Also Present: Thomas Polgar
UNCLASSIFIED
620
pb3
UNCUSSIFIED
CONTENTS
WITNESS
GLENN A. ROBINETTE
By Mr. Van Cleve
NUMBER
GR-1
GR-2A-B
GR-3
GR-4A-B
GR-5A
GR-6A-B
GR-7A-F
GR-8A-E
GR-9A-B
GR-IOA-B
GR-llA-B
EXAMINATION
EXHIBITS
FOR IDENTIFICATION
UNCUSSIFIED
621
UNCUSSIHED
UNdlASSIHED
PROCEEDINGS
Whereupon,
GLENN A. ROBINETTE
was called for examination by counsel for the Plaintiff and
having been first duly sworn by the notary public, was
examined and testified as follows:
MR. BARBADORO: Mr. Robinette, it's my understand-
ing that you intend to rely on your Fifth Amendment rights
and not to testify to the committee in this or any other
proceeding unless you are ordered to by a court and granted
limited use immunity. Is that correct?
THE WITNESS: That's correct.
MR. BARBADORO: I want to give you now copies of
orders obtained from the United States District Court for the
District of Columbia for both the House and the Senate.
These orders compel you to testify and grant you limited use
immunity .
I give you a copy of these orders and also have
them marked for the record.
[Robinette Deposition Exhibit Nos .
GR-1, 2A-C, 3, 4A-B, 5A-B, 6A-B,
7A-F, 8A-E, 9A-B, lOA-B and llA-B
were marked for identification. )
For the record, we are satisfied with
^ MiwpfMMeM of LO. 12356
i4li b. I Mm, Nalwiil Security CouncM
MR. TUOHEY:
both orders and we intend to proceed accordingly.
622
UNCLASSIRED
MR. BARBADORO: Thank you, Mr. Tuohey.
EXAMINATION
Q Mr. Robinette, I want to get right to the point
with Richard Sscord in 1986. And let me first ask you, did
there come a time in March of 1986 when you were hired by
Richard Secord to do some work for him?
A That's correct.
Q And do you know the date that you were hired by Mr.
Secord?
A No, it would probably be the last week of March; in
that time period.
Q I want to show you Exhibit GR-1, which is your
calendar for the year 1986 and ask you to look at it and turn
your attention to the month of March of 1986. In reviewing
that calendar, I see only one meeting with Richard Secord in
March, and that was on March 19.
Could you look at that exhibit and tell me, was
that the date where Mr. Secord hired you?
A I see it. I can't accurately testify as to the
19th, but it certainly is in that time span of the last — the
latter part of the last week of March, to my recollection.
Q That <=^^^^tfM#|f ^1 /ff^Vffi^l^ reflects the fact
that there was a meyliyfL fWmll 11^14^ *'ith you, Secord,
623
UNCUSSIFIED
Tom, which would be Tom Clines, correct?
A Tom Clines, yes.
Q And Chi-Chi, which would be Chi-Chi Quintero; is
that right?
excuse me, I'm sorry. I apologize. I was looking below. it
says Hoyt. I'm sorry.
Yes, that's Chi-Chi Quintero.
Q Do you recall meeting with those people at Mr.
Secord's office on March 19, 1986?
A No, I don't, but I'm sure I did.
Q Would Tom Clines and Chi-Chi Quintero have been
present on the date that Mr. Secord hired you to do work for
him?
A To my recollection, I doubt if Mr. Clines or Mr.
Quintero knew anything of General Secord's hiring me at that
time.
Q So you don't think that you would have been hired
at that meeting on the 19th?
A If I was, I don't think they would know it. It's
the kind of conversation, knowing General Secord, that he
wouldn't necessarily discuss it in front of them.
Q Do you know what the purpose of that meeting was on
March 19th?
itiynrK^inpn
and then something
UNCIASSIHED
about an attorney in South Carolina — his name is Hoyt —
regarding a bill, something pink slip. And I can't recall
what pink slip means. It probably has something to do with
payment, or I don't know.
Q So you can't remember what the purpose of that
meeting was, correct?
A No, but it looks like social to me. Dinner and
drinks .
Q I'n any event, you recall that you were hired by Mr.
Secord some time in March of 1986, correct?
A Yes.
Q What were you hired to do?
A I was hired to conduct research and investigation
on allegations being made against General Secord.
Q Can you describe in general terms what those
allegations were?
A Yes . General Secord commented that there were
people unknown to him who were saying that he was involved in
drug trafficking and arms shipments and generally illegal
type activities.
Q And what kind of investigation did he want you to
do of these allegations?
A He said he didn't know who these people were, and
he wanted to know if I could find out who they were and their
background and why-tlipy^giu^d J)V'Ba2iiia-i*^®'® derogatory.
iilMli'tfM]til*n "' '"
625
UNCLASSIFIED
Q And how much did he propose to pay you for this
work?
A Originally we discussed it and I think we said
$3,000 a month, but I asked for$4,000 a month plus expenses.
Q And he agreed to pay you that amount?
A Yes, he agreed.
Q And when did you start actually working for him?
A Probably the first week of April.
Q Do you recall when you first got paid?
A No, I don't recall but probably toward the end of —
middle or end of April.
Q And that would have been for work you did for him
during the month of April and March?
A Yes.
Q Do you recall whether you were paid by check or in
cash?
A I think cash.
- Q After the first cash payment you received from Mr.
Secord for this work were you later paid by check for some of
the work you did for him?
A Much later in the year.
Q Take a look at Exhibits 2-A, B and C
A Yes, I see them.
Q Those are checks
• -•■Ml k
oWflWft
tanford Technology
626
UNCLASSIFIED
A Yes, they are.
Q They are made out to you?
A Yes, they are.
Q And they are signed by Richard Secord?
A Yes.
Q The first check is dated June 9, 1986, correct?
A Yes, it is.
Q And the second check is dated June 26?
A Twenty-four.
Q Twenty- four. And the third check is dated?
A August 11.
Q August 11. Are these checks that you were paid by
Mr. Secord for the investigative work you were doing for him?
A Yes, they are.
Q And that is for work that you did in the months of
May, June and July of 1986?
A Yes.
- Q Did you continue to work for Mr. Secord after July
of 1986 on this investigative assignment?
A Yes, I did.
Q How were you paid for the work you did after July
of 1986?
A By cash.
UNCLASSIFIED
Q When you were paid in cash, did you sign any
627
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receipt for the money that you received?
A No, I did not.
Q And did you keep any record of the cash payments
A No, I did not.
Q For how long did you continue to receive these
payments?
A I was paid up through, I think, November maybe
December '86, and they stopped. And then in March of '87 i
received one payment of $2,000. Q And that$2,000 payment, was it in cash or was it
paid by check?
A That was a check, I believe.
Q Did you do investigative work for Mr. Secord for
which you were not paid?
A I continued through January, February — March was a
partial payment, it was $2,000 instead of four. And I think I probably stopped just about early April. Q And you have not yet been paid for that work, correct? A No. I had told him in, I think, early January that I realized he had a lot of problems, newspaper articles and so forth, and would undoubtedly have other expenses, and that I was willing to continue on a time available basis — my time available--to recej.yg .iiL^^44W'JVlf*i|f'*^Ainvestigations that miwiwtncn"""' 628 IINCUSSIFIEO I had initiated. And then in March I spoke to him along the same lines, but told him that if he had any available funds they would be appreciated. And I don't recall his exact words at that time, but he said this was the best he could do at that time and gave--I think he had his girl give me a$2,000 ,
check. I don't remember receiving it, but I got a $2,000 check. Q rfow much money does General Secord owe you for the investigative work that you performed for him? A Well, if we put it around$4,000 a month up until
mid-April it would be maybe $15,000,$14,000, something like
that. But if he were to come into some funds and there
wasn't so much problem, controversy, I probably would ask him
for it. But I don't think I would pose that question to him
at this time.
Q Do you still expect to be paid for the work?
A I don't know.
Q Are you saying that you don't intend to ask General
Secord for the money at this time because you don't think he
has the money to pay you?
A That's right.
Q And if he does at some point have the money to pay
you, you intend to ask him for it? |||Lin| i|00lPlf*l\
A Yes, because I have billsUl lULnOuiri Lli
629
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UNCUSSinED
Q Let me turn to a different subject. Did there come
a time in the spring of 1986 when General Secord talked to
you about installing a security system at the residence of
Lieutenant Colonel Oliver North?
A That's correct.
Q Could you look at your calendar, Exhibit 1, and
from that calendar can you identify the date when General
Secord first talked to you about installing the security
system?
A Yes, I can.
Q And what's that date?
A It's the latter part of April, April 29, 1986.
Q Now where were you when he brought up the subject
of the security system?
A I believe in his office in Virginia.
Q Was anyone else present at that meeting?
A No, I was in his room, in his suite in Virginia. I
Q As of that date had you ever met Lieutenant Colonel |
Oliver North? !
A No, I had not. * |
Q Had you ever spoken with him? I
A No, I had not. i
Q Had you ever heard his name mentioned before?
A I think I had heard it mgntipned, _yes
nentioned, yes.
UNCLASSIHED
630
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A Probably General Secord or Mr. Clines.
Q What did they say about Lieutenant Colonel North?
A That he was working in the White House, and
probably identified him at that time as being with the
National Security Council. And being a very hard worker,
that type of thing.
Q Let's go back to the 29th, and can you tell me as
best you can remember what General Secord said to you in that
meeting about the need for a security system at Colonel
North's residence?
A General Secord described, mentioned that Colonel
North had been experiencing threats to his home. And specifi-
cally mentioned one in which lights were being shined on the
house at night, which frightened his wife and family espe-
cially when he. Colonel North, was not there, because as I
understood Colonel North was frequently not at home.
threatening phone calls, I believe sugar in the gas tank,
flattened tires and unknown packages in the mailbox, which is
external to the house.
Q What do you mean by unknown packages?
A Packages not sent by the post office department,
but packages that have been--boxes of some type that were put
in there by persons unknown, which it was interpreted could
be threatening such as a bomb.
631
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bomb though, did he?
A No, he did not.
Q But collectively, the matters that I've just
identified resulted in a feeling of severe uncomfortableness
by Mrs. North and Colonel North for their family.
Q Did General Secord also say something about the
fact that Colonel North was frequently away from home?
A t don't know if he did at that meeting, but at the
next meeting it certainly came up that he was--and certainly
Mrs. North told me that subsequent to this meeting.
Q Was there any discussion at this April 29 meeting
A The word terrorist might have been used at the
April 29 meeting, but subsequent it was used.
Q Did General Secord say anything to you at this
April 29 meeting about the kind of security system that he
wanted you to have installed?
- A No, he knew that I was familiar with security, all
phases of security and he deferred to me to go out and look
at the property and make some recommendations .
Q Did he say anything at this meeting about who was
going to pay for this system?
A No, he did not.
Q What else did he say at the meeting about the
UNCUSSIFIED
632
security syst
UNCUSSIRED
A That's about all that I can recall.
Q After he told you about the need for a security
system, what did he do?
A He asked me if I thought I could handle it, and I i
agreed. And would I agree to handle it; yes, I would. And I
i
he then said he would call Mrs. North to make — to identify me |
and make arrangements for a meeting with Mrs. North.
Q And did he call Mrs. North while you were at his
office?
A Yes.
Q what did you do after General Secord called Mrs. j
North? I
t
A I then called Mrs. North, it seems to me within 45 |
minutes later to identify myself and get an agreed time for a
meeting with her.
Q And what was said in your telephone conversation
with Mrs. North?
A I identified myself by name telling her that I
think she had recently heard from General Secord and that I
was coming out there to look at her property, the possibility
of implementing some security procedures to protect the
family.
Q And what was her reaction
A Very brief, but yes, and she would meet me the next
ICUSSIFIED
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day. And we agreed on a time.
[Off the record. }
Q Mr. Robinette, when did you go out to the North
residence?
A I went out the next day, April 30th.
Q What did you do when you got out to the residence?
A Met with Mrs. North, introduced myself and briefly
specifically about the lights that were shining from the
walk around the house and the property.
Q In general terms can you describe the North
residence, the property and the area in which the residence
is situated?
A It's located in Great Falls, Virginia. It's a two-
story house situated in the middle of a plot of ground with
houses on each side and a woods to the rear. There's a fence
enclosing all the property. Not a secure fence, just simply
a fence to keep the animals from getting out. They had two
horses at that time.
Had a built-in garage. Fairly rural area, wasn't
well traveled out there.
How big is the lot?
VNCUSSIFIED
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UNCLASSIFIED
A I'm going to say an acre. I'm guessing on that.
Q How far back is the house from the street?
A The roadway--let 's see, the house sits back off the
Q And how far away are the houses on either side of
I
the North house? !
A Probably an equal distance of 200 to 250 feet.
Tell me what happened once you got inside the house?
During this visit?
Yes.
I commented that I spoke to Mrs. North. She
described to me that — in response to my questions she
described that, yes, she had experienced on several occasions
lights — someone a topping :Cn^.tito. ro^ .j«|jid»- ynd- L Ioshi^iQ ,:„
lights fe^ ^SHSBMI^ use at night. Colonel North was not home
and it certainly frightened her.
I can't recall at the moment whether it also
occurred when Colonel North was home. But she did describe
in response to my questions that Colonel North didn't usually
arrive until around midnight every night at which time she
there had been occasions with threatening phone calls. She
made no reference to the^^^^t^^e^ ^ij^uf^Jif sugar in the
gas tank.
Q After speaking with Mrs. North, did you walk around I
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the house?
A Yes, I did.
Q And after looking at the house and speaking to Mrs.
North did you draw any conclusions about the kind of security
system you would need to install at the house? i
A Yes, I did. It didn't take too long because it's a
I
fairly standard residence, and it became quite obvious that j
security at the house would be difficult because of the j
family lifestyle; four children and two horses and dogs and
cats.
Q What effect did the fact that he had children, dogs
and cats have on the kind of security system that you planned
to install?
A Well, if you were concerned about someone entering
into the property within the house at night and you had the
security system on, you would normally have some sort of IR
beams, intrusion alarms that would go off, would be alerted.
But the best you can do under the circumstances with children
running around at night and dogs and cats is to simply wire
the doors and the windows with the hope that the system would
be turned on and that if someone forced their way through the
window or the door, at that time an alarm would go off.
Q Is it safe to say that because of the animals and
the children you felt that a passive system rather than an
active system ^"^o^v^£'9>'VJM"^>''^^AIf IPA infrared beams
636
UNCLASSIFIED
would be required for the house?
A Yes. I felt also that Mrs. North, who appeared to
be extremely concerned about her children, would be able to
carry a portable transmitter, something very small that as
she walked through the home or out in the back of the
property that if she was accosted or alarmed at some point
that she could press this wireless transmitter which in turn
would automatically set off an alarm.
Q D'id you describe for Mrs. North the kind of
security system you were thinking about?
A I probably touched on it, but I perceived that she
wasn't personally interested in the details. I think she
would be more responsive to simply knowing that a system
existed.
Q What else happened at your visit to the North
residence?
A That's about the extent of it. I think I left
. Q Did you on a later date meet with Colonel North to
discuss the security system?
A Yes, I did.
Q And from your calendars can you determine when that
(ting occurred?
A Yes, I can.
Q When was thati
UNCUSSIFIED
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UNCLASSIRED
A That was on May 5th, 1986.
Q How did that meeting come about?
A I believe between May 5th and the time that I'd
been to General Secord's I reported back to him that I'd made
the visit and I had a general idea what I thought would be
useful, but it was necessary in my experience, that the user
know what was contemplated. And I suggested that General
Secord either tell Colonel North that which I would tell him,
or General Secord and I meet Colonel North.
And on the 5th of May, General Secord and I did- go
to Colonel North's office at 7:00 or 7:30 that night.
Q Was it General Secord who arranged the meeting with
Colonel North?
A Yes, he did.
Q The meeting occurred at 7:30 on May 5th?
A Yes, it did.
Q And it was at Colonel North's office, correct?
A Yes, in the Old Executive Office Building.
Q And you went to the meeting with General Secord?
A Yes.
Q Who else was present in Colonel North's office when
you got there?
A When we walked in, I believe 'FlWmftn^WS there in
the outer office. And then General Secord and I walked into
the inner office, which I recall was to the right of the
638
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outer office. And we sat down, and that's the only person I
recall seeing at that time.
Q What happened at the meeting?
A The meeting was brief. I think it took about 30
minutes and told — General Secord introduced me to Colonel
North, told him that I was the man that had surveyed the
property and--had surveyed Colonel North's property and that
I had some proposals for equipment that I wanted to discuss
with him, with Colonel North.
Q What happened then?
A I summarized very quickly what I thought would be
useful considering the family lifestyle that they had. And
in addition, I suggested that if he concurred that I would
also attempt to put in a visual surveillance system of the
mailbox in an attempt to — the mailbox and the mailbox area in
an attempt to identify who was leaving the packages at night
and perhaps who was pausing on the highway to shine lights.
Q What kind of visual surveillance system did you
have in mind?
A At that time it was either going to be a still
camera that would be operated electronically each time the
mailbox was opened, or it would be a wireless video camera.
In either case, both would maintaif A f Sf 2J^4 °i ^ho stopped
or who opened the mailbox door.
I had some tentative plans for maybe having it^also
mssifii
639
UNCUSSIRED
be operated from the house, but that was tentative because I
didn't think that either Mrs. North or Colonel North would be
able to turn on the camera in times of emergency.
Q What happened after you described the kind of
system you had in mind to Colonel North?
A He said, okay, that sounds good. Let's get
together when you have more firm— when you've formulated your
plan.
Q As of May 5th, had you contacted any contractors
A I think 1 contacted more than one. But there was
really one firm here in the Washington area that I had
previous experience with and knew the personnel as b eing
extremely reliable. ^^^^^^^^^^^^^^^^^^^I^^^H^^^I
^^^^^^^^^^^^H And I felt that to
because of their ability and reliability.
Q What is the name of that company?
A The name of the company is VATEC.
Q A» of May 5, had you obtained an estimate of how
much this security system was going to cost?
A No, I don't believe so because I hadn't — I don't
believe so because I don't think J.^ad^firmed up in my mind
just what I was going to have.
Q Was there any discussion at this meeting on May 5
about who was going to pay for the security system?
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A No, there was not.
Q Did General Secord say anything else at the meeting
other than to introduce you to Colonel North and describe to
Colonel North the fact that you were the one who was working
on the security system for him?
A No, he did not.
Q Was anything else said at the meeting other than
what you've described?
A Nothing that I can recollect.
Q When did you meet with Colonel North again?
A Let's see, that was on the 5th. I met with Colonel
North on the 10th of May at approximately 10:30, Saturday.
MR. BARBADORO: Let's go off the record for a
second.
Q
A
Virginia .
Q
A
Q
A
Q
[Discussion off the record.]
Wh«re did this meeting take place?
It took place in General Secord 's office in
Who arranged this meeting?
General Secord.
Was General Secord present at the meeting?
Yes.
Was anyone else present, other than you and Colonel
North and General Secord;
ssent, otner tnan you ana
UNCUSSIFIED
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A No.
Q What happened at this meeting?
A This was an opportunity for me to tell Colonel
North, in more detail, just what I thought they should have
at the house. And I, in turn, related what I thought they
should have.
Q Could you describe for us, in general terms, what
the system was that you had in mind?
A Yes, it's pretty much as I mentioned earlier.
There would be — the doors and the windows would be alarmed
n case anyone attempted to force their way in there. There
would be smoke and heat detectors. There would be the
portable transmitter, one or two, which Mrs. North could
carry around, and perhaps one of the older children, or even
Colonel North.
There would be external lights shining on the
property that would come on at night in the event of an
alarm. I believe there was an audible alarm, I believe. I
can't remember whether that was installed or not.
In addition, there would be an audible signal
installed in one of the vehicles in the event that Mrs. North
or one of the children was using the car and there was an
attempt to kidnap them or force them off the road, I felt
that a loud sounding ,^ijen_ or whistle would scare the people
away.
ig siren or whistle would
UNCUSSIHED
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UNCUSSIFIED
Also, there would be a radio control system at the
front gate so that when Mrs. North came in or went out, the
gate would always be closed and she or anyone else, with
these two transmitters, could open the gate without having to
get out of the car. They would always be in the car.
And lastly, there was a discussion at that time,
that I was still looking into a video type, or pictorial type
of coverage of the gate and the mailbox. I hadn't really
defined that at that time.
I also described, lastly, that this whole system
would be connected to a central station alarm company that
would receive signals 24 hours a day, every day of the year,
and that when an alarm was received they would contact the
authorities to send them out.
Q So the way the system would work is that if the
alarm went off in the house, it would also ring at this
company who could notify the police, correct?
A Correct.
Q At this point, you were planning to have VATEC
install the entire system, correct?
A Yes , I was .
Q Had you obtained an estimate from them as of May
10, as to how much this system was going to cost?
A I don't believe so. I think it was shortly
thereafter, very shortly thereafter.
I/NCI ilWiFiFn
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UNCLASSIFIED
Q From your own experience, in working in this area,
did you have a rough idea as to how much you thought the
system would cost?
A I thought the system would be about $10. to$12,000.
Q Let me ask you, was there any discussion of how
much the system would cost, at this meeting on May 10?
A Yes, there was.
Q Could you describe that discussion?
A Yes, I don't recall who instigated the question or
the subject of the money, whether it was Colonel North or.
myself, but the result was that Colonel North commented that
he'd like to keep the price between $8,000,$8,500, that he
was a poor colonel and he wanted to try to keep it around
that figure.
Q Mr. Robinette, was it you who first raised the
figure of $8,lto$10,000, or was it Colonel North?
A I think it was Colonel North.
MR. BARBADORO: Let's go off the record for a
second .
(Discussion off the record.]
[The reporter read the record as requested.]
Q Mr. Robinette, during the break, you've had a
chance to speak to your counsel. Do you now wish to correct
UNCUSSIRFD
644
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A Yes, I do.
A We were discussing the approximate costs of the
system. It's my recollection that I stated the cost would be
around $8,000 to$8,500 and, in response to that. Colonel
North said fine, keep it around there, I'm on a poor colonel's
pay.
Q Let me just make sure I understand your testimony
then. Earlier, I asked you if you had a rough estimate of
the cost of this system, and you answered between $8,/and — Do you want to correct between$10, and 512,000, excuse
that answer as well, or do you want to stand by that answer?
[Counsel and witness conferring.]
THE WITNESS: At the time, we're talking now of
Saturday the 10th of May, the figure that I quoted was $8,000 to$8,500.
Q The figure that you quoted to Colonel North?
. A Yes, to Colonel North, yes.
Q My question then ia if you thought it was going to
cost between^lO^fand 12,\ why did you quote to Colonel North a
figure between 58,000 and $8,500? A There was some debate in my mind about this monitoring system, which may or may not be used at that gat I didn't think I'd ultimately use it. ICUSSIFIED 645 UNCIASSIHED Q So you decided to give Colonel North an estimate in the low range of what you thought the system would cost? A I felt if we implemented the security system as I had described, I didn't think we'd really need the video system. Q The second point of clarification, at this meeting on May 10, who was it that raised the question of how much the system would cost? Was it you, or did Colonel North ask you about How much it would cost? A I think it was me. Q And when you said that you thought the system would cost between S8,000 and$8,500, what was Colonel North's
reaction?
A He stated, as I had said a few moments ago, okay
keep it around that figure, I'm on a poor colonel's pay.
Q What else happened at that meeting?
A That's about the extent of it. It was a very short
meeting. I got the impression that Colonel North and General
Secord were meeting for other reasons and my participation
was really very small.
Q Did there come a time when you made a down payment
to VATEC for the security system?
A Yes, that's correct.
Q Take a look at Exhibit 3, which is a check from you
to VATEC in the amount of $6,000. I/NCI IW/FIFD 646 _ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 ■UK) —pom w u CO.. nc i07 C Sow. N E 25 UNCDISSIHED A Thank you. Q Do you recognize that check? A Yes, I do. Q Is that the down payment that you made to VATEC? A Yes, it is. Q That check is dated May 19, 1986. Is that the date that you made out that check? A Yes, it is. Q 'What did you do with the check after you made it out? A I believe I personally gave it to a representative of VATEC, who came to my home. Q Had work started on the system as of that date, or was that down payment required before work was to begin? A As I recall, I don't think work had actually started. I had made a trip or two back out to Mrs. North's but no, I don't think work had started. As I recall, they wouldn't start the work until they had — they couldn't order the equipment until they had money . Q When you made out this check to VATEC, you were using your own funds, correct? A I was using my checking — yes. Q Did you subsequently look to someone for reimburse- ment for this down payment? ONCLASSIFIFn 647 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 ONCUSSIRED A Yes, I did. Q Who did you look to for reimbursement? A General Secord. Q When was that? A Either on that day, the 19th, or on the 20th. Q Did you go to General Secord's office to get the reimbursement? A Yes, I did. Q How much did you ask General Secord for? A To my recollection, it was$7,000.
Q Why did you ask him for $7,000, in view of the fact that the down payment you made was for$6,000?
A The additional $1,000 was for expenses that I had incurred in looking into this system. Q Is it fair to characterize that$1,000 as part of
your fee for the work you had done in connection with the
security system?
A I think so.
Q When you asked General Secord for the money, did he
give it to you?
A Yes .
Q Did he pay you by checJ^pX-in cash?
A He gave me cash.
Q Where was he when he gave you the cash?
A I believe he was in his office, in his suite.
648
UNCLASSIFIED
Q Where did he get the cash from?
A I don't know where he got the cash from. To my
recollection, I was sitting at a desk, sitting at his desk,
sitting in front of his desk, and he leaned down and either
took it from a drawer or took it from a case.
Q Did he count the money before he gave it to you?
A I don't recall.
Q what was the denominations of the bills that he
paid you in?
A I can't actually recall today.
Q Did General Secord express any surprise when you
went to him for reimbursement for this security system?
A No, he did not.
Q — H x^^^l^ ad any previous discussions with General
Secord about Tn^Tact that General Secord was going to pay
for this M i ra i uutr?
A No, I did not.
Q Why did you look to General Secord, rather than to
Colonel North, for this payment?
A I was working for General Secord. He was the one,
in my opinion, that had assigned me the task and that was the
natural — in my opinion, that was the natural place to go.
Q So even though you installed the system at Colonel
North's house, you looked to General Secord for payment
because he was the_Qr\e^tiiat Ud^tlife^UCu to install the
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UNCUSSIFIED
system, correct?
A I did. I did, yes.
Q What did you do with this cash that General Secord
gave you on either the 19th or the 20th of May?
A I took it home.
Q I want to show you Exhibit 4-A and 4-B. Exhibit 4-
A is your bank statement for the month of May and Exhibit 4-B
is a deposit slip.
gxhibit 4-A, the bank statement, reflects that
there was a deposit to your account of $7,000 on May 20. -Is that the deposit you made with the cash that General Secord paid you? A Yes, it is. Q Exhibit 4-B is a deposit slip in the amount of$7,000. Is that also the deposit slip for the $7,000 deposit that you made with the money General Secord gave you? A I'm sure it is. Q When you went to General Secord, to seek reimburse- ment for this down payment, did General Secord say anything to you, that you should go to Colonel North and ask him for the money? A No, he did not. (q) And General Secord never said anything to you about him getting the money from Colonel North to pay you, did he? A No, Genera iiriorisi^^tcitrit anything to me 650 UNCUSSIHED about doing that and, in fact. General Secord never told me that he. General Secord, would pay for the system. (^ And he never told you where the money was coming from, to pay for this system? A No, he did not. Q Is it fair to say that as of May 19, when you made this down payment to VATEC, that you were expecting that VATEC would be the sole contractor for this system? A Yes, it was, at that date, yes. Q At some point, did you make a decision to use another contractor for a portion of the system? A Yes, I did. Q What part of the system did you decide to give to another contractor? A The remote control, the electronic gate. Q What caused you to decide to give the electric gate contract to someone else? A I thought that VATEC 's proposed charges for the electronic gate were high and I also had some impression that maybe it was a type of installation that they weren't able to do easily and cheaply. Q When did you first receive an in a Ui uawnt from VATEC? A I think I got a verbal estimate from them sometime in June, mid- June, early June. Q Wouldn't vou have received an estimate fr^nTthem il estimate from them som UNCUSSIRED 651 pb34 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 iiNcussra prior to making the down payment on May 19? A Probably, yes. Q Do you recall what that estimate was? A I believe it was around 11-something, 12-something. Q Did that first estimate you got from them include the electric gate? A I don't recall right now. MR. TUOHEY: Excuse me. [Witness and counsel conferring.] [Discussion off the record.] [The reporter read the record as requested.] BY MR. BARBADORO: Q Mr. Robinette, 1 had asked you if that first estimate you got included the electric gate. Your answer was that you couldn't recall. Have you had a chance to think about that answer? A Yes, I have. That was a verbal estimate that was given to me by a member of VATEC. Q Did it include the electric gate? A Yes, it did. Q It's fair to say that the estimate would have been substantially higher than VJ'rf l^i -^ ^_ ^i included the gate? A Yes, it would. Q When did the installation of this system begin and when was it completed, approximately? 652 1 2 3 4 5 6 7 8 ' i 10 I ^'! 12 I 13 I 14 i 15 16 17 18 19 20 21 22 23 24 UNCLASSIHED A It Started sometime in May and ended in early July. Q The dates you gave me, does that include the installation of the electric gate by the other contractor? A Yes, it does. Q What is the name of the contractor that installed the electric gate? A I think it's Automatic Gate. Q Did Automatic Gate require a down payment before they installed the system? A No, I don't believe they did. Q Did there come a time when you made final payment & to VATEC and also final payment ~»r the automatic door company, for the work that that was done for you? A Yes, there did. Q In looking at your calendars, can you determine when it was that you made that final payment? A Yes, I can. Q When was that? ' A July 10, 1986. Q Can you describe the circumstances in which you made these payments? A Yes, I spoke to both contractors, who agreed to meet me at noon at a restaurant in Silver Spring and I timed it so that I would meet one contractor at one point and the other contractor at a second point, so. that there wouldn't be IniKi iKhifiFH 653 any IINWSSW :ing of the two contractors. Q How did you plan to pay them, by check or with cash? A No, I was going to pay them with cash. Q Where did you get the cash from, to pay them? A Cash that I had accumulated and kept in my home. Q Please take a look at Exhibit 5-A, which is an invoice from the VATEC Corporation. Have you seen that exhibit before? A I've seen it recently. It was shown to me. Q That is an invoice for the security system that' was installed at the North residence, correct? A That's correct. Q In the upper right-hand corner, it bears an address of ^^^^^^^^^M property and that's the North residence, correct? A That's correct. Q It also says payment received 7-10-86. Is that the date that you made final payment to VATEC for the work done on the system? A Yes, it is. Q By looking at the invoice, can you tell the amount of the payment that you made on July 10? A Yes, I can. Q What is the amount that you paid VATEC on that day? A 55 70. IIMPIflCOirirn 654 UNCIASSIHED Q You had earlier made a down payment of S6,000, correct? A Yes. Q So what was the total amount that you paid VATEC for the work that they did at the North property? A 511,703. Q Please take a look at Exhibit 6-C, which is an invoice from Automatic Door Specialists. Have you seen that before? A Yes . Q That invoice is for work that Automatic Door did for you installing the electric gate at the North property, correct? A That's correct. Q And that invoice reflects that that work was done at the North residence, correct? A That's correct. Q It also states that payment was made on July 10, 1986, correct? A That's correct. Q Is that when you paid Automatic Door? A That's correct. )u Day them for the work iClASSIFIED Q How much did you^ajr^hem fc'^^h_^_work they did? A 52,173. Q You paid them in cash at the restaurant on July 10, 655 UNCLASSIRED correct? A Yes, I did. Q So if you paid VATEC 511,703 and you paid Automatic Door Specialist S2,154, the total cost of the installation of the system was 313,857. Does that sound right to you? A I accept your addition. Q In any event, it's approximately$14,000?
A Yes, it is.
Q Mr. Robinette, you testified that you used your own
funds to make these cash payments on July 10, 1986?
A Yes, I did.
Q Did you subsequently seek reimbursements from
somebody for these funds?
A Yes, I did.
Q who did you go to for reimbursement?
A General Secord.
Q On July 10, you paid approximately $7,800 to these t%«) contractors. How much money did you seek from General Secord? A Subsequent to this date, I asked him for ap- proximately S9,000. Q Why did you ask him for ^S.9_,0QiJ_whprvXflvu^Jlflifli1&nts to the contractors were$7,800?
A My expenses, gas, time, telephone.
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UNCUSSIFIEO
A Yes.
[Counsel and witness conferring.]
Q How long after July 10, 1986 did you go to General
Secord and ask him for reimbursement?
A I don't recall the exact date.
Q Do you remember when it was that you got paid?
Q In August, 1986? Does that sound right?
A Yes, if I saw the check, I'd probably recognize it.
MR. TUOHEY: Off the record.
[Discussion off the record.)
Q Let me show you Exhibit 7-F, which is a cashier's
check in the amount of $9,000? A Yes. Q Have you seen that before? A Yes . Q That check is made payable to you, correct? A Yes, it is. Q And it bears the notation that it is from CSF Investments, Limited? A Yes, it does. Q And the date of the check is August 20, 19861 A August 20, 1986. UNCLASSIFIED 657 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 UNClASSra Yes, it is. What did you do with that check? I put that in an account at Merrill Lynch. Mr. Robinette, is Exhibit 7-F a copy of the check Q Is that about the time that you received the check, sometime shortly after August 20, 1986? A Yes, it is. Q Is that the payment you received from General Secord? A Q A Q you received? A Yes. Q Does the back of the check bear your endorsement? A Yes, it does. Q And that's the check you received from General Secord for the reimbursement for the payments you made plus your fee for the security system, correct? A Yes, it is. Q Between the beginning of May and the time when the system was paid for, did you ever go to Colonel North and seek reimbursement from him? A No, I did not. Q Did you ever send Colonel North a bill for any of the work you had done on the security system during this time period? A NO, I did not. ONCUSSIFIED 658 UNCIASSIRED Q Did General Secord say anything to you, during this time period, that suggested that he was obtaining the money he was paying you from Colonel North? A No, he did not. MR. BARBADORO: Let's go off the record for a second. [Discussion off the record.] BY MR. BARBADORO: Q Mr. Robinette, do you recall making any other payments in connection with the security system? A Yes, I do. Q What payments did you make? A I had to pay the Central Station Alarm Company and I had to pay VATEC for electrical work that was done. Q A Q A Q VATEC? A Q A Q How much did you pay the alarm company? I believe it was$90.
What was that payment for?
Services for, I believe, a six month period.
What were the payments and how much did you pay
I paid VATEC the $90. And they forwarded it to the security system? Yes. You also mentioned making other payments to vatec, It CO tne security sysLt UNCIASSIHED 659 _ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 -,. I UNCUSSIFIED ^2 I ■MLLW n v omwta eo.. mc »- c Sut.t St. 2 5 A Yes, I paid VATEC S140 to go fix, repair that electric gate. It was faulty and the company would not acknowledge that it was their problem. Q Did you seek reimbursement from anybody for these payments? A No, I did not. Q Why not? A I don't recall why. It was a small amount and I just felt that I had been paid for it. Q I want to move ahead to November of 1986 and ask you about a date that's now familiar to everybody, November 25, 1986. That was the date that Attorney General Meese held his press conference and announced that the funds from the Iran arms sales were diverted to the Contras and also announced that Colonel North had been removed from the National Security Council staff. Let me ask you, where were you on November 25, 1986: A I was in Costa Rica. Q What were you doing there? A Doing some — continuing with my work with General Secord on research investigation. Q When did you return to the United States? A November 29, 1986. Q At some point in December, after you returned from UNCLASSIRED Costa Rica, did you receive a telephone call from Colonel 660 UNCLASSIFIED North? A Yes, I did. Q When did you receive that phone call? A My recollection is not — it seems to me it was shortly thereafter. Q Are you reasonably certain that it was sometime in December, before Christmas? A Yes, very much so. Q What did Colonel North say to you, in this phone call? A We passed the time of day for a moment or two and said that -- he mentioned to me that I had not sent him a bill for the — Q Give me his exact words, if you can? MR. TUOHEY: On that particular issue? BY MR. BARBADORO: Q On that issue. A To my recollection, it was something along the lines of a very friendly comment, like hey, you know you haven't sent me a bill for that work, security work that you did at my house. How about sending me the bill. Q What was you] A I said yes, Q What was the tone of his voice? A He was very friendly, I thought in a good frame of :::riNCUSSlFl[D 661 MTCStretT NE UNCLASSIFIED mind, considering that at that period of time he was having what I considered major personal difficulties. Q At the time you received this call, you knew that Colonel North had been removed from the National Security Council staff, correct? A Yes, I did. Q And you knew that he had hired a lawyer? A Yes, I did. ! Q You also knew that he was being investigated by the FBI, correct? A I assumed he was being investigated by not only the FBI but a number of federal agencies. Q When he called you in December and asked you to send him a bill for the work you had aone, did you expect him to pay you for the work? A I didn't really know, but I doubt it. Q You knew that you had already been paid for the work by General Secord, correct? A Yes. Q Were you surprised that he called you in December, several months after the work had been completed, and for the first time asked you for a bill? A Yes, I think I was surprised Q It's fair to say, Mr. Robinette, that you knew why he was asking you for this bill, correct? VNCUSSm 662 _ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Huan RVoxTwa co.. w^ UNCLASSIRED A I think so. Q And he was asking for this bill to cover himself because he was under investigation by the FBI and other federal agencies, wasn't he? A Yes, he was. MR. BARBADORO: Let me just go off the record. [Discussion off the record.] [The reporter read the record as requested. ) BY MR. BARBADORO: Q Mr. Robinette, did you think that Colonel North was asking you for a bill because he wanted to pay you the money that he owed you for the security system? A No, I didn't. Q Isn't it true that you thought, at the time, that Mr. North was asking for a bill because he wanted to cover himself because of the federal investigation that was then ongoing, correct? A I can't respond exactly to Colonel North's thinking, but I think he felt that possession of a bill would be helpful to him. Q I'm really interested here, not in Colonel North's state of mind, but in your state of mind. Your state of mind was you assumed that you were being asked to provide a bill that could be used to cover the installation of the security system, correct' iiNdi hmm 663 UNCUSSIFIED A Yes. MR. BALLEN: Why did you assume that? THE WITNESS: Because he had not been billed. BY MR. BARBADORO: Q Isn't it true there are several reasons why you assumed it? You assumed it because the system had been installed months ago and Colonel North hadn't come to you at the time and requested a bill, correct? A Correct. Q You also assumed it because you had sought and ' obtained payment from General Secord for the system, correct? A Correct. Q And you also thought it was true because of the circumstances at the time, where Colonel North was under investigation when he asked you for the bill, correct? A Correct . MR. TUOHEY: Off the record. [Discussion off the record.] BY HR. BARBADORO: Q After you received this phone call from Colonel North, what did you do? A I typed up an invoice, probably within several days, within one to two days of his phone call and mailed it. Q Mr. Robinette,- let me show you Exhibits 9-A and 9-B. A Yes, I have them. IINfllASSIFIED 664 _ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 XMK KVOMTWO CO.. MC- CSimiNE 25 iiNcussm Q Are those invoices that you prepared after this December phone call with Colonel North and then sent to Colonel North? A Yes, they are. MR. TUOHEY: Paul, I'm not nit-picking, but he prepared an invoice, xeroxed it, and then typed a note. BY MR. BARBADORO: Q Exhibit 9-A is an invoice dated July 2, 1986, addressed to Colonel North for the security system in the amount of$8,000, correct?
A That's correct.
Q And Exhibit 9-B is a copy of that invoice with an
additional note written on the bottom, dated September 22,
1986, correct?
A That's correct.
Q Is it fair to characterize Exhibit 9-A as a first
notice and Exhibit 9-B as what is intended to be as a second
notice?
A That's correct.
Q Mr. Robinette, did Colonel North ask you to send
him a bill or did he ask you to send him copies of bill?
A In my recollection, he said send me a bill.
Q What you sent to Colonel North, however, was a bill
dated July 2, 1986 and a second notice which was the original
bill with an additional "°^s, '^fl'^^^f itfifeft 22 typed on it.
665
UNCLASSIRED
correct?
A That's correct.
Q Why did you send him a first and second notice,
instead of just sending him a bill?
A I selected the dates because the first date of 2
July was approximately when the equipment was -- the install-
ation was completely finished. And the second date of 22
September was when the installation was working satisfactori-
ly-
Q Mr. Robinette, my question is what was your purpose
in sending him these two pieces of paper?
A To help him, to assist him.
Q In wh?t way?
A Because he hadn't been billed.
Q Again, you weren't expecting Mr. North to pay you
for this system, correct?
A No, I was not.
Q And there was a reason why you sent him a first
notice dated July 2 and a second notice dated September 22,
wasn't there?
A Yes.
Q Tell me what that reason was?
A I responded in response to his request and those
were the dates that I felt represented the true status of the
equipment for the installation.
IIMPI ACCIClcn
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IINCUSSIFIEO
Q Wasn't it your purpose to provide him with a
plausible explanation as to why he hadn't paid you as of
December, 1986?
A I don't think so, but it was to provide him with
documentation.
Q Exhibit 9-B, the note that you wrote and dated
September 22, 1986, says "Oilie, due to my schedule, I have
from the dates, I'm sure that you have had the same problem.
Please remit when you have time."
my paperwork, that wasn't correct, was it?
A No.
Q That was a deliberate misstatement?
A Yes.
Q What was the purpose in making that deliberate
misstatement?
MR. TUOHEY: Do you understand the question?
THE WITNESS: I think so.
MR. TUOHEY: Excuse me.
[Witness and counsel conferring.]
MR. TUOHEY: Can we take a break?
■Recess .
UNCUSSIRED
Mr. Robinette, I'm going to ask you some questions
667
UNCLASSIRED
before, but I'm going to try to put it all together here.
invoice dated July 2, 1986, correct?
A That's correct.
Q Mr. Robinette, you did not prepare this invoice on
July 2, 1986, did you?
A No, I didn't.
Q You prepared it in December of 1986, correct?
A That's correct.
Q The invoice states that it is for the installation
f the security system that you installed at Colonel North's
house, correct?
A That's correct.
Q The amount that you are billing Colonel North is
$8,000. That amount is not what the system cost, correct? A That's correct. Q That amount is an incorrect statement of what the system costs, right? A That's correct. Q I want to turn to Exhibit 9-B, which is a copy of 9-A except for a note on the bottom, dated September 22. That date is incorrect, isn't it? You didn't prepare that note on September 22, did you? A That's correct. UNCLASSIHED 668 1 2 3 4 5 6 7 8 9 10 11 12 i 13 14 15 16 17 18 19 20 21 22 23 24 . MC. 25 UNcussm Q You prepared that note in December, didn't you? A That's correct. Q Indeed, you prepared the note at the same time you prepared the first exhibit, dated July 2, 1986, didn't you? A That's correct. Q So that date is false, right? A That's correct. Q In the note, you say "due to my schedule, I have not found time to follow up on my paperwork. " When you said that, that was not true, was it? A That's correct. Q When you mailed these bills to Colonel North, you mailed them at the same time, didn't you? A That's correct. Q When you mailed them to him, did you mail originals or copies? You mailed copies, didn't you? A Yes, I believe so. Q Can you explain why you made all these misstatements in these two exhibits and why you mailed copies to Colonel North, rather than original bills? A At that period of time. Colonel North was in what I considered a great deal of — having experienced a great deal of problems and troubles and I thought that documents -- [Telephone ringing ] [J NClASSIF IlD [The reporter read the record as requested.] | _ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 UNCLASSinED THE WITNESS: And I thought that possession of these documents would be helpful to him. BY MR. BARBADORO: Q How did you think the possession of these documents would be helpful to him? A Colonel North had not been billed for the system and had not paid for the system. Possession of these documents would indicate that payments were expected. Q It would give Colonel North a plausible explanation to anybody who might ask as to why he hadn't paid for that system himself? A That's correct. Q Did you hear from Colonel North after sending him these bills? A I didn't hear from him by telephone but shortly thereafter I was surprised to receive two documents from Colonel North, in response to these bills. Q Take a look at Exhibit 10-A and 10-B. A Yes, I have them. Q Are those the letters you received from Colonel North in response to the bills you sent him? A Yes, they are. Q HOW long after yQ)i ^SPS- l}i!!L the_bins^ did you get these responses? A I'm only able to guess, but I'd say within a week. 670 tlNEUSSIflEO Q A Q copies? A Did they come together or did they come separately? They came together. Do you recall whether you received originals or I think I got copies. Q Before I get into these, I want to just go back to the two bills you sent. Can you describe how you sent these to Colonel North, the two bills. Exhibits 9-A and 9-B? A How I mailed them? Q Yes. A Yes. Q Please do that. A I mailed them to Colonel North's attorney. I selected the attorney's address rather than his home address because I didn't think he's get them. I knew his attorney, knew of his attorney, his name had been in the paper and I knew the office and the location. Q Did ycu double seal the bills? A Yes, I did. Q So that the outside envelope was addressed to the attorney and the inside envelope was addressed to Colonel North, correct? A That' Q Back to the responses that you got from Colonel North, the first one. Exhibit 10-A is a letter to you from '■— UNCUSSIflEO 671 UNCLASSIFIED Colonel North dated May 18, 1986. Did you ever receive this letter from Colonel North on or about May 18, 1986? A NO, I did not. Q So the first time you ever saw this letter was in December, 1986, correct? A That's correct. Q The second letter is again from Colonel North to you and is dated October 1, 1986. Did you ever receive this letter on or about October 1, 1986? A No, I did not. Q The first time you saw this letter was in December, when Colonel North sent it to you? A That's correct. Q I want to read from the second paragraph of Exhibit 10-A and that paragraph begins "It is my understanding that the full system will cost approximately$8,000 to $8,500." Mr. Robinette, did you give Mr. North that understanding in May of 1986, that the security system would cost between$8,000 and $8,5007 A Tes, I did. Q I will continue, "That it can be installed quickly" did you give Mr. North, and I'm asking you did you give Mr. North the impression that the system could be installed quickly in May of 1986? A I believe so. UNCLASSIFIED 672 UNCLASSIFIED Q I will continue reading, "And that we have two options for reinbursing you for the expenses: one, loan of the equipment for a period not to exceed the expiration of my active service in the United States Marine Corps (June 1988). At that time, we will make our home available for commercial i endorsement of your firm and the equipment, without fee." Did you ever present Colonel North with this option No. A I Q You never offered to loan him the security equipment ] until he ended his active service with the Marine Corps, did you? A No, sir, I did not. Q And he, in turn, never offered to make his home available for commercial endorsement of your firm and the equipment without a fee? A No. Q The second option he describes in the letter states that he will "make payment in full for the equipment and tht cost of installation in 24 equal monthly increments, commenc- ing on the date that the installation is completed and fully operational . " Did Colonel North ever offer to make payment for the system in 24 monthly payments A No, he did not. Q In fact, he never offered to pay you for the UNCUSSIFIED 673 wtmm installation of the system, isn't that right? A That's correct. Q I will turn to the second letter, GR-IO-B and read from the third paragraph of that letter. Colonel North says to you, "Back to the point, your note of September 22, it was our understanding that we were going to go ahead with the first option for first reimbursement, that is commercial endorsement of your company and the equipment when I retire from the Marine Corps in 1988. " You've already testified that you never offered Colonel North that option. Is that right? A That's correct. Q So you never had agreed with Colonel North that he could have the system in exchange for him making some kind of commercial endorsement of the company and the equipment when he retired from the Marine Corps? A That's correct. Q At the bottom of the note, what is apparently in Colonel North's handwriting is the P.S. "Please forgive the type, I literally dropped the ball." Do you know why he added that note to the letter? A I have no idea. Q The typeface is a little bit different on this letter than it is on the letter dated May 18, 1986. Do yovj know why the typeface appears to be different? UNCLASSIFIED 674 UNCLASSIFIED A No, I do not. MR. TUOHEY: Off the record. [Discussion off the record.] BY MR. BARBADORO: Q What did you do with these letters after you received, Mr. Robinette? A I just — these two letters from Colonel North? Q Yes. A Came as quite a surprise and I just threw them in my drawer, file drawer. Q Did you ever tell General Secord that you had sent bills to Colonel North and that you had received some letters back from Colonel North? A Yes, I did. Q When was that? A Sometime in this same time period of December. Q What was General Secord 's reaction? A Very noncommittal. Just simply yes, okay. Q Did General Secord express any surprise that you were sending Colonel North a bill in view o£ the fact that General Secord had already paid for the security system? A No. Q Did he tell you it was wrong to send Colonel North bill? A No, he did not. uNcussra 675 UNCLASSIFIED Q When was the next time you spoke with Colonel North? A I believe March 16th, 1987. Q And that's when he telephoned you, correct? A That's correct. Q And what did he say in that phone conversation? A Said he hadn't seen me in some time and let's get together for lunch. I had suggested a commercial restaurant downtown and he said, no, that wasn't a good idea because of the publicity about him, and he suggested his attorney's office the next day. Q And did you agree to meet him? A Yes, I did. Q Did ycu also hear from--strike that. Before going to lunch on the 17th of March with Colonel North, did you hear from General Secord? A Yes, I did. Q And he called you as well, correct? A Yes, he did. Q What did General Secord say to you? A He called in regard to a newspaper article that had been published that day. Q Tell us what the newspaper article was about. A It was in regard to the security installation at Colonel North's residence that I had participated in and made reference to an interviey. ^Bl«r*«4ftilPI'Pw(.ew that I had iisi(*iirc?l0fft' 676 UNCUSSIFIED had. General Second commiserated with me. He said sorry that I was involved and getting notoriety, and wanted to get together to talk. I told him that I was coming downtown that day the 17th, March 17th to meet Colonel North and he suggested meeting a time right after that. Q What happened when you got to Colonel North's lawyer's office that afternoon? A The day before Colonel North had asked me to lunch and also to bring the documents which I then had in my possession. Q So in his telephone conversation with you on the 16th, Colonel North asked you to come to lunch at his attorney's office and he asked you to bring with you the bills and the letters concerning the security system, correct? A That's correct. Q Now please continue and describe what happened when you got to lunch. A I met in a conference of — his lawyer's conference room. It was a very brief luncheon, very brief meeting of about 40 minutes. We discussed the family, his children. He made two telephone calls. And then asked if I had the--if I had brought the documents with me. I said, yes. He said, let's go upstairs to see my attorney. Q And which attorney did you go up_tp^seeT A \ nentleman named Barry Simon. IIELASSIEIED 677 yn C imn. N I mmm Q And what happened when you got to Mr. Simon's office? A He introduced me to Mr. Simon and left; Colonel North left. Q And tell us what happened when you met with Mr. Simon. A Mr. Simon and I had a brief informal discussion about the building and security. And then Mr. Simon raised the question, did you bring some documents down. I said, yes. Can I see them? Yes, I showed them to him. He asked if he could make copies, and I said, certainly. He attempted to give them to his secretary who was not at the desk, and he went and made copies . He returned shortly thereafter — I'd say within three to four minutes — returned my copies to me and had his copies in hand. He sat down and glanced at them and said something along the lines, you did prepare these, or you prepared these, correct? And I said, that's right. And that was about — and just about at that time Colonel North came back into the office. I perceived the meeting was over and Colonel North took me back out of the office to leave. Q Where did you go after leaving the attorney's office? A I then went over to meet General Secord at the go alter leaving tiie ai-uu UNCUSSinED 678 UNCUSHD Capitol Hilton Hotel at 16th and K. Q Did Colonel North come with you? A No, he did not. Q What happened when you got to the Capitol Hilton? A I went in the bar. General Secord was not there. He did arrive within 10 minutes. We both had ordered drinks, or I had ordered a drink earlier. He ordered a drink. He commiserated again with me about the newspaper article expressing some sympathy that now my name was in the newspa- per. Q Did he say anything to you about the bills? A Yes, he did. Q What did he say? A The subject of the bills came up and he said, well, you sent him bills, didn't you? And I said, yes. He said, well, fine, you don't have anything to worry about. You did right — you did the right thing. Q What else was said at that meeting? A That was about it. He appeared to be in a hurry and he left shortly thereafter. Q Have you spoken to Colonel North since this meeting on the 17th? Q Did you Sullivan? "miKsra ttorney Brendan 679 UNCLASSIFIED A Yes. Q When was that? A That was on that same day. Later, almost within 15 minutes of Secord's leaving. Q And what did Mr. Sullivan say to you? MR. TUOHEY: Let me just interrupt, if I may, Paul. Just one thing. Just so it's clear, I think Glenn ought to describe the circumstances. My understanding is Sullivan didn't know where he was, and I don't want to be unfair to somebody. MR. BARBADORO: Let's go through that. THE WITNESS: But I do like the idea, did you get a call or I would have forgot. BY MR. BARBADORO: Q What were the circumstances under which you received this call from Mr. Sullivan? A Shortly after General Secord left I received a call on my beeper. And my beeper is a display type which shows the number. And I called it and it was Brendan Sullivan's number who is Colonel North's attorney. Q And what did Mr. Sullivan say to you? A He might have commented about the newspaper article, just commiserating. But he said that he wanted me to--he wanted to tell me a couple of things, which he did. He said, don't cover ^OE-QPlSffl -Noptb^ Jjs'jj^ big boy, or 680 iiNcussm something to that effect, or he's a big man. And tell the truth. And the third was, he suggested I get an attorney. MR. BARBADORO: Let's go off the record. [Discussion off the record.] MR. VAN CLEVE: Let the record reflect that we've reconvened and Mr. Ballen has stated that he does not have any questions for the witness at this time. Mr. Robinette, I do have some questions. EXAMINATION BY MR. VAN CLEVE: Q Let me start out by asking you, sir, today we did not go through the normal biographic details, but I want to have this fixed in my mind for other purposes. How old are you? A Sixty-five. Q Okay. And you have been employed — you left the Central Intelligence Agency about how long ago? A I left in 1971. Q And have you had regular employment since then? A No, I've worked part-time or self-employed. Q And I believe you testified earlier today that you went to work for Richard Secord sometime in March of 1986? A That's right. Q Had you ever previously worked for Richard Secord' A No. UNCIASSIRED 681 UNCLASSIFIED Q Or for Thomas Clines? A No. Q Or for Edwin Wilson? A No. Q Now I believe you also testified that you were paid a substantial part of your total compensation from Mr. Secord during 1986 was money you received in cash; is that correct? A That's correct. Q Would it be fair — this is just an estimate and I don't want to hold you to this — but to say that it might have been as much as$25,000 in cash?
A Yes.
Q Possibly $35,000? A Yes- Q Had you, during your prior self -employment from 1971 through 1986, had you ever before been paid by a client in cash? A No. - Q Whose idea was it that Mr. Secord would pay you a substantial part of your total compensation in cash? A The subject was never discussed. I don't know. It must have been his idea, I guess. Q Is it your testimony that it seemed natural to you to receive$35,000 in cash^a^fter having^ never ^een paid that
way before? iiiviii r^ili]
682
VNCUSSIFIED
A No, but I didn't question it.
Q You didn't ever ask to be paid in check?
A No, I didn't.
Q And you were never asked for a receipt of any kind
by Mr. Secord?
A No, I was not.
Q And you have no written records of the amounts that
you were paid; is that correct?
A No, I do not.
Q Now I believe you did testify that you received
$16,000, a total of$16,000 in the form of checks during
1986; is that correct?
A Yes.
Q And was the sole purpose of those payments compen-
work for Mr. Secord?
MR. TUOHEY: Let me just correct something, George.
There are two checks for five and one for six, which is 16.
But there's also the check for nine. Did you clarify that
they viel^mo^ for Secord?
MR. VAN CLEVE: I'm sorry, perhaps I misspoke.
THE WITNESS: It's apples and oranges.
BY MR. VAN CLEVE:
Let me back up here. Exhibit 2 for the deposition
contains three checks; one in the amount of $6,000 and two in Pb66 M> C Satn N C _ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 I CO.. HC. 25 vNcussn the amount of S5,000 each. And my question was, is it your testimony that the sole purpose of those checks was to pay you for your fees and expenses on behalf of work you did for Mr. Secord? A That's correct. Q And that work was totally unrelated to the instal- lation of a security system; is that correct? A That's correct. Q And I believe you testified previously that at some point in late April 1986 you were approached by Mr. Secord and asked whether or not you could help to provide a security system for Oliver North's home? A That's correct. Q And that you're not sure, if I understood your testimony correctly, whether or not the subject of terrorist threats against Colonel North came up at that time or later; is that correct? A That's correct. Q But it did come up at some point? A Yes, it did. Q Can you tell us what was said to you on the subject of terrorist threats against Colonel North? A Yes. It was described to Q Or his family. Q It was described to me that Colonel North had^ UNCLASSIFIED 684 )07 C SntR. N I. UNCLASSIHED experienced a number of unusual circumstances at his house and that he was concerned for himself and his family. Specifically the name of Abu Nidal was mentioned as a principal terrorist represented a threat to Colonel North. And that since the North residence was frequently — since Colonel North was not at the North residence frequently, he wanted some kind of protection for his family. Q Were you ever given any specific information about the nature of these threats or the reasons why--you're a former Central Intelligence Agency officer. Were you ever told what type of information might have supported the idea that there were threats being made? A NO. Q Were you ever told anything else about that subject? A No. Q Were you told that at one point there had been guards posted at the North home? A Yes, I was. ■ Q And will you tell us what you were told on that subject, please? A Yes, I believe Colonel North told me at one of those meetings; early meetings that there had been two guards stationed or assigned to his residence and that they stayed in the built-in garage area. And that his experience with them was not satisfactory. 685 UNCLASSinED Q From what you were told, were you able to determine whether these guards were private guards hired by the Norths or guards provided by the federal government? A No, I was never told that. Q And were you told about what time the guards had been stationed there? Would it have been about this same period of time? A I'm gathering it was prior to my entrance on the scene. Q But in the recent past previous to that? A In the recent prior time. Q You were told that the experience that they'd had with the guards had been unsatisfactory? A Yes. Q Was that suggested to you as a reason why they needed a security system? A NO. Q To replace the guards? "A No, I don't think so. No, it was not suggested to me. Q Were you told at that time — this would be in the spring of 1986 — that at one point Colonel North's family had actually physically been removed from their home in response to earlier threats that had been madj A Not that I recoiled """ICLASSinED 686 UNCiA$sra
Q Now when you set out to design the security system
for the North home, this would have been probably in the
beginning of May 1986?
A Correct.
Q Was the design a design that was left pretty much
A Yes, it was.
Q And if I understood correctly, the basis of the
design was an inspection of the North's home, together with
your conversations with Mrs. North, together with conversa-
they were looking for; is that correct?
A That's correct.
Q And I believe you told us earlier today that when
you met with Mrs . North she described a variety of problems
unknown origin, that there had been sugar put in gas tanks of
cars that were 200 feet off the road and so on. Does any of
this sort of thing, based on your professional experience,
sound the like the kinds of things that terrorists do?
No.
Does it sound like.v.
WSSIFIED
Q Now the security system that you designed, was it
•signed to protect against vandals or was it designed to
687
9
10
11
12
13
14
15
16
17
18
19
20
21 i
UNCLASSIFIED
protect against terrorists?
A It's primary value would be against vandalism, but
I would hope it would be a deterrent in some way to terrorists
who might attempt to force their way into the house, at least
she would get an alarm.
Q But would a —
A And she could, of course, then easily alert help
with the built-in system.
Q I know this is a difficult question, but in terms
of a private home, protecting a private home against a
potential terrorist attack with limited resources available,
would the kind of system that you put in have provided
reasonable protection?
A Against terrorists?
Q Against that kind of an attack?
A It would give them some prior notice, prior alert
that someone was forcing their way into the house, whether it
was a terrorist or a good guy or a bad guy. It's just simply
a — perhaps it was something to help Mrs. North's peace of
mind. But as you know, protecting against terrorists is a
very difficult job. Certainly the U.S. government has a
Sure. Let me sharpen this question a little bit.
24 iobviously, the Norths did not have unlimited resources. They
^^j!!!rTr''"' 2 5 I couldn't spend the kind of money that you would spend to
NCLASSilK":
688
UNClASSinED
protect the United States Capitol.
A Yes.
Q But taking that into account, were they receiving
protection really against neighborhood vandals? Or weren't
they receiving something considerably more sophisticated that
would, in fact, allow some warning against a potential attack?
A The latter, yes, what you had described. Protect-
-some early warning against a potential attack. Ideally, if
the home style had permitted it, there should have been
something put in the grounds so that as people, as individuals
came through the open fence and they walked through this
several hundred feet, the house would be alerted that someone
was walking there.
But when you have children, dogs, cats and horses--
you have to try to marry a reasonable protection system into
a lifestyle. And their lifestyle was typically family. You
couldn't restrict them in any way and have the system operate
reasonably well .
Q Okay. I believe you told us the other day — and I
don't mean to hold you to this, but my notes reflect that
when you described the situation the other day you told us
he described to you the possibility that you would undertake
this job. And you told us, if my notes are accurate, that
initially ar least you thouaht Sl'lf .Ull ■W'lt'^ would be paid
689
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«NM«D
for by Colonel North; is that correct? That you had an
impression that that would be the case?
A It was a completely — it was an assignment completely
detached from what I was doing for Colonel North— I'm sorry,
for General Secord, pardon me. And I would assume that this
was Colonel North's need for some professional assistance and
I didn't know who was going to pay for it at that time.
Q You did know that Colonel North was a government
official?
A Yes.
Q And you're a former federal government official
yourself, right?
A Yes.
Q Turning to the meeting of May 5th, which I believe
was the sort of first meeting you had with Colonel North
dations. He indicates, as I understand your testimony, that
he wants to meet again.
I believe you testified that at that meeting there
was no discussion of price; is that correct?
A At that meeting, yes.
Q He didn't say, for example, that he couldn't afford
to spend more than a certain amount or anything like that?
A Not to my recollection at that meeting.
I believe yo
."AVlKMrfli*ll
I want to confirm
690
UNCLASSIHED
73
this for the record, that in your view North clearly was the
one who was making the installation decisions; what would go
into the system, what would not go into the system?
A I felt it was his — well, it didn't seem unusual to
me. Yes; yes, in response.
Q He was the client, in effect, for this job, wasn't
he?
A Yes, it was his house.
Q Right, I understand. Secord had come to you, but
he appeared to be the client for the job; is that right?
A [Nodding affirmatively.]
Q Now at the May 10th meeting — and we've gone over
this a little bit earlier this morning, but I want the record
to be as clear as it can be on this subject. This is the
meeting where there is discussion of the price for the system
and you give him sort of a final configuration.
A Yes.
Q And my question to you is, who brought up the
question of the cost of the system? What is your recollection
on that point?
A I think I brought that up.
Q Now within about 10 days or so between May 10th and
May 19th you got at least some estimates for a significant
part of the total job frj
A Yes.
mmmw
691
uHCUSsra
Q And these estimates came in a lot higher than the
$8,000,$8,500 that had been discussed at that May 10th
meeting. Is it a fact that you never consulted with Colonel
North after the May 10th meeting about how much the system
was going to cost?
A Yes, that's correct.
Q Instead, you did check back with General Secord to
see if the higher estimate was acceptable to him; is that
correct?
A Yes, I believe I mentioned it to him, yes.
Q And I believe you told us that at all times you
looked to Mr. Secord for the payment?
A That's correct.
Q So both in terms of approving the estimates and in
terms of payment, you looked to Secord for the payment?
A Yes.
Q And you don't know whether or not there might have
been some arrangement between Secord and North; is that
correct?
A No, I do not know. General Secord never mentioned
anything like that to me.
Q Now as a former federal employee, did it occur to
you that there might be a problem if General Secord was
paying for the installation of this 3\
A No, it did not occur to
inraiiED
692
UNCLASSlFIEir
UNCLASSIRED
Q So you thought it was okay for federal officials to
accept large gifts from other people for this sort of thing?
MR. TUOHEY: If we were in a deposition I would
object to that question as argumentative.
MR. VAN CLEVE: I can rephrase it, but I'm asking
based on his prior experience as a federal employee.
THE WITNESS: I have to say, yes, I don't think
or whatever it was .
BY MR. VAN CLEVE:
Q I mean, based on your current understanding, that
is what happened here, isn't it? You've told us that Colonel
North has never paid a penny for' this system. That it cost
$14,000. A I thought you were talking of at that time in March or April or whatever. Q I can say it as of the middle of May, if you like. I can say it as of the present, if you like. Q Whichever way you prefer. Q I was initially interested in your state of mind at the time because clearly you were dealing with Mr. Secord in getting his approval, looking to him for payment, and yet you ow whether there was any arrangement. So I was asking, at the time, what was your state 25 I of mind about this? I mean, did you think this was a 693 UNCUSSIFIED 76 I perfectly proper arrangement? A Yes. Q And why was that? A Because I didn't think there was anything wrong with it at that time. I didn't know what arrangements had been made or were being made. MR. TUOHEY: Off the record for a second. [Discussion off the record.] BY MR. VAN CLEVE: Q I want to turn now to the period after November' 25th, Mr. Robinette. I'd like to ask you to try--and maybe looking at your calendar will help you a little bit to place in time some of the events a little more precisely. I don't know that it will be--do you have a copy of the calendar? A Yes, I do. Q I don't know that it will be material today, but it may be material at a later point. A Okay. Q I believe you told us that on December 9th that you were interviewed by the FBI? A December 10th. Q My apologies . On December 10th you were interviewed by the FBI. And as I recall your testimony o;f the interview, you said that you were asked generally about the Iran arms sales, some questions ^^i^\^Mi?^99tf§^r%^^'^ about your mai 694 UNCLASSIFIED relationship with Secord; is that right? A I think so. You know, the best thing is to look at their records or show them to me or something. Q I can just tell you that whether we have them or not, I have not done that and haven't had a chance, and I'm not going to pursue it in detail. Were you asked about Colonel North at that inter- view? A I could have been. But again, I don't have a clear recollection of what they asked. They spent about an hour at my home . Q I'm not trying to put you on the spot, I'm just trying to see what you remember. A I can only answer-- Q You don't remember? A No. Q Okay. Now my notes reflect that you told us that on December 11th you then got a phone call. Was it December nth? A Yes, it was. It looks like 12:00 from the agent. Q So this would be the next day? A Next day. Q And it was a follow-up call by one of the agents that had interviewed you the day before; is that — A Yes. UNCLASSIFIED 695 UNCUSSIFIED Q And my question is — and I apologize for that sort of lengthy introduction — did the phone call from Colonel North come before or after the FBI had interviewed you in December? A That was asked yesterday. I can't recall. Q You don't have any way of placing the phone call in time? A No, I notice my appointment calendar for December is rather blank. I don't know whether it was me or what, because I usually have a lot of notes on there. But I don't know. There's no way for me to reconstruct that in my memory. Q Now we went over some of this ground and I am not at all interested in having the record be different on this point than it already is. But I believe you told us that the reason that you changed--you made out two bills that you put false dates on them and so on — that one of the reasons was that you wanted to protect Colonel North? A That's right. ' Q Mr. Robinette, you didn't know Colonel North at all before May 1986; is that right? A That's correct. Q And you've never had any social dealings with him? A That's correct. Q And you really don't have any way of knowing much about his performance in the qovernment, do you? 1^ iiiiAi if*0%inrw %, UNCLASSIFIED A Personally, no. Q So other than by general reputation, you really don't know Colonel North? A That's correct. Q Why would you want to protect him? A The few times that I did see him, I was impressed with him. In addition. General Secord had talked — had commented to me about Colonel North. And I think Colonel Dutton had commented to me. And I know Tom Clines had commented to me, all in the same lines, along the same lines that Colonel North was a super hard-charger, a workaholic, and a never-give-up type. Another point that would affect my actions was I was extremely impressed with Mrs. North and the family and the lifestyle, and the problems that she as a mother and a wife had to put up with. She had a pretty tough time out there with Colonel North always working and she having to do a lot of things on her own. Q Now you knew it was important to General Secord to continue his relationship with Colonel North, didn't you? A No. Q No? A Are you speaking in regard to those notes, those bills- UNCLASSinED 697 UHtmSW I A No, I would have--no, my concern with — my actions with the bill was primarily for Colonel North. Now as far as important that General Secord continue with Colonel--! don't know. I don't know what they were doing. I don't know if it would be important or not. MR. TUOKEY: Let me ask a clarifying^ Are" you asking whether or not a secondary motive or an alternative motive in preparing these bills was to protect General Secord? MR. VAN CLEVE: That's part of the question. THE WITNESS: I think that's true to a degree, but I don't know--that's true to some degree. But my primary objective was Colonel North. BY MR. VAN CLEVE: Q Have you ever asked General Secord whether he's received any kind of payment from North for the system? A No, I've never asked him. Q Even after the stories were in the paper and you met with him on March 17th, that subject never came up? A Never asked him. It just never came up. MR. VAN CLEVE: I have a couple of additional questions. I don't mean to be unnecessarily personal. But bearing in mind that this is an executive session and that I have not personally had the time to do the background review that we would normally _(4p_ here. _ _I hope^ counsel will bear with me. 698 UNCLASSIFIED MR. TUOHEY: Off the record. [Discussion off the record.] BY MR. VAN CLEVE: Q Mr. Robinette, have you ever been arrested? A No. Q Have you ever been indicted by either a state or a federal agency? A No. Q And I take it that you have never ple^d guilty to any charge that would amount to a felony? A No. Q Would you please tell us the nature of the lawsuit that you're currently involved with down in South Carolina? A He's suing us for failure to -- Q Who is he? A A fellow who is a principal in a firm. The firm is named Sisco and his name is Mario Salvador and he's suing for failure to meet terms of a contract. - Q Are there any allegations that claim fraud in the business relationship? A I don't know. He had a lengthy number of -- you mean about us or about me? Q Yes. You or your business partners? A No, not that I know of but you have to look at their records. I'm not being evasive, I lust don't recall m not being evasive, Ilw i iupi ftooid cn 699 UNCUSSinED 82 Q How much money is involved in the lawsuit? I'll take an approximate number. How much is the claim being made against you? A I think he wanted$750,000 or we promised to pay
him over ten years, or something like that. I might now be
right on that. Somebody's been down there, I know. The
attorney said.
Q That may be, sir, but I can tell you for what it's
worth that they haven't been talking to me.
I am struck by the fact that you appear to have
voluntarily decided, in December 1986, that you were going to
go out of your way to try and protect Colonel North while he
was under investigation, as you knew, at the time by various
federal agencies and officials. As I understand your
testimony, you did that purely out of a disinterested
personal concern for Colonel North and his family, is that
correct?
- A That's correct.
Q Obviously, the testimony you are giving here today
is going to have just the opposite effect when it's given in
public, isn't that so?
A Opposite effect?
Q I think it's fair to say that this testimony is
going to be very «^3'"*gi"3 ,*^iL,*^°l°Ji?ik ffflff |»|t®" ^^'^ given in
700
iimsim
public, isn't that so?
A Probably, yes.
Q Did it occur to you, in December of 1986, that you
might end up across the table, where you are today?
A No.
Q Why not? Didn't you think that federal inves-
tigators were going to be pursuing this matter?
A If it didn't occur to me, in December 1986, that's
why not. it didn't occur to me.
Q Mr. Robinette, you've spent a considerable part- of
your career as an intelligence' officer, isn't that so?
A Yes.
Q Surely you're aware of the investigative resources
available to the federal government, aren't you?
A Yes.
Q Do you mean to tell us that when you backdated
these bills, it never occurred to you that anyone was going
to figure this out?
- A No, I probably wouldn't have done it. As everybody
says, in hindsight, they wish they hadn't done something.
MR. VAN CLEVE: I have nothing further right now.
Thank you.
[Whereupon, at 1:15 p.m., the takiQfl. flf _the
deposition was concluded.
[Whereupon, the witness having been
701
pb84
UNCLASSIFIED
deposition, waived signature.]
UNCUSSIFIED
507 C Suttt. N E
702
pb59
wusjife
CERTIFICATE OF NOTARY PUBLIC
I, PAMELA BRIGGLE, the officer before whom the
foregoing deposition was taken, do hereby certify that the
witness whose testimony appears in the foregoing deposition
was duly sworn by me; that the testimony of said witness was
taken by me and thereafter reduced to typewriting by me or
under my direction; that said deposition is a true record of
the testimony given by the witness; that I am neither counsel
for, related to, nor employed by any of the parties to the
action in which this deposition was taken; and further, that
I am not a relative or employee of any attorney or counsel
employed by the parties hereto, nor financially or otherwise
interested in the outcome of the action.
fdpi^ Ikt^^L
PAMELA BRIGGLE
Notary Public in and for the
District of Columbia
My Commission expires May 14, 1990.
UNCUSSIFIED
703
(Rol^/vei^
lOOTH COHOKEsi'' RESOLUTION f-j,/
1ST SESSIOM ^
of the Senate Select Coramlttee on
Secret Military Assistance to Iran
and the Nicaraguan Opposition
To iianunize from use in prosecution the testimony of,
and other information provided by.
Glen A. Robinette
June 4, 1987
MR. IMOUYZ, the Chairman of the Senate Select Committee on secret
Military Assistance to Iran and the Kicaraguan Opposition,
submitted the following resolution to the CoimUttee, which
approved it by unanimous vote of its eleven members on
the 4th day of June, 1987.
Whereas, the Senate select Conniittee on Secret Military
Assistance to Iran and the Nicaraguan Opposition is con-
ducting an investigation under authority of Senate Resolu-
tion 23, 100th Congress, and will conduct proceedings to
Whereas, the Select Caenittee may require Glen A. Robinette
to testify and provide other infotmatlon at its proceedings;
Whereas, Glen A. Robinette has refused i a testify or provide
other information at proceedings of the Select
Coaalttee on ground of self-incrimination; and
Whereas, pursuant to 18 U.S.C. $S 6002 and 6005, a committee may seek, by two-thirds vote, a court order immunizing testimony and other Information provided by a witness from use in prosecutions other than for perjury, giving a false state- ment, or otherwise failing to comply with the court order: Now, therefore, be it Resolved, That the Select Committee on Secret Military Assistance to Iran and the Nlcaraguan Opposition, pursuant to 2 u.s.c. it ^BSDia; ana ^oar, aireccs cne Senate Legal Counsel to apply for a court order inwunlslng froa use in prosecutions the testimony of, and other inforaatlon provided by. Glen A. Robinette at proceedings of the Senate Select CooBlttee on Secret Military Aasiatance to Iran and the Nlcaxaguan Opposition. 704 ^//.' ~ //2-5;cnro to SAT {c^jyr. r'r^-orAt /I . .. _ <^^^^^ ) Cmo.I C^uz/C -^rs^ U^ it^^ li' ^uijj/,) 705 S^ TO iLEX MANftGER . 72£3 ig t»leK: 08399 GENEVA AUGUST 20TH, 1986 ; ATTN nRS nORABlA PLEASE ISSUE A CHECK IN THE AMOUNT OF USD 9 000,-- TO THE ORDER OF G.R. ROBINETTE AND HAIL IT DIRECTLY TO : G.R. ROBINETTE 3265 ARCADIA FL NW ■WASHINGTON DC 20013 TEST KEY NO 151 THAN* YOU IN ADVANCE tEST REGARDS CSF INVESTMENTS LTD. •• Start o< re.pon.. .. •♦ Telex sent 16:03:33 DATE: 20/08/86 TIME: 16:03:33 REF: 08399 02T 421434 23421434- .^ : AUG 20 1003 t214r.4 &LICBAN1- 428463 CSF CM CI 426663 CSF CM 421434 &LICBANK •• End o* e< 6?.-7> 706 1^1 1 Cf JC.'f fl.\tw^\itj F- ^ •v^^ -L 2z /.u. ;s jsi ''."i'^.OO (-' :ttl P. 3 no;: i.., .:n iMi-;i/,.i:.Tj:: 5-:, ,r. .rv TCP h 707 r 3 5 X - U (J u u a- (M rvj (V Kl O O IT o <0 ■ .- f in Ki lo ' a IP r i . r^ o 45 »• w o . •^"^ * in , ■ !; 1 t • O"* 1^ ^ 1 |t c : s 1 1 { J « £_ . ^^X.0~0-O.O.O.O.A <0 <0«<D«><DOC«CO c er cecoccoooe o — r.^r?u-ru-?craJ-^rN> J J J — s- 2_ oruru/\jrurur\j(\jru(\j C1 <5 c? (M I • -:i o o o o i o o ff- o o M t^ 1^ If r r h. As 6 <\) 4 V II x> -^ \ • \ % •»»• O-fOroo — ou-iin ru O 1 <D <T a- o \r or^ r~ fXJ i. 1^ e « IP o- IT \/> fCi ^ «J 11 K100— Mfoa-nj tn m Si •3000 «joa-o- m Is — 1/^ * O- — f^ — <0 <o ll O Jl li •2< 2 « lo r» >- If bJ K »- Z u < o ec . ixocqcq: OEZaa: -» UJ UJUJUJUJ hJ<UJUJ <J > oooo oaoo o xoc ac <r ocoaco: b. oooo OIOO o a j 3 '^'^zszxszzz «J i UJUUJUJUJUJ UJUJtiJ z -1 srxriiirrri < < - -1 o J Q.Q.Q.Q.Q.Q.<jaaQ. m — X^-D,0^-O^-0-0>O j> i a<o<o«j<D«3<oa3(Deo _ ,^ 708 208G23 ,.R. KSIHETTI Republic National Bank of New York ^ 4S2 Fllir) A«tnut • N*«r York, Nto York 10011 t/10/t6 ^„ . . „,J 9,000.00 ^S> xg «« H» TOUK MSUItl C S F iNl^TUEWrS LTP \i\ ."^^ nn 9,000. QO \ ItUCOMMilSiON unAMOUXT ^, 000. 00 6x. 6?-7E 709 710 ?3 a§. ! 5 ! i ./^s. 711 < > - „- ; - - c ; - T .-. i ^ >- «. S 1 ':^'^/ " ^ >■::"'■- ."I ; - - ^ - X ~> :: e o e 1 1 1 i . ■ i 1 " 1 -1 1 i 1 1 1 ^ 1 1 1 s r s i . — Is '' i 5 -V - II- '"■ CI £ — i o c . 1 ,5 r ■N i > i ^ - -| ' ' M I 1 1 ~ ■ :-: 1 ■ g i ** „ s * ° 1 712 713 r- ■ ! ^ , , i • 1 7 1 1 \ 1 ^1 ; 1 1 J 1 1 ! -} -_ i i ^ -' 1 i '1 :! i 1 I 1 1 '1 1 ' 1 1 ' J L 1 ' 1 ! 714 2^^^ e 5 - < c a c *•>-■ 1 s 1 s f i fc> [ i i_ . r i £ - - '.' ■ t 1 1 1 i 1' I ! 1 1 715 Glenn Robinette & Assocuites lliS ARCADIA PLACE. NW R B 262 WASHINCrON. DC JCOU 2 July 1986 Lt. Col. Oliver North 703 Kentland Drive Great Falls, Virginia 22066 For Installation of Security Equipment, Systems Services at 703 Kentland Drive, Great Falls, VA. (This equipment should prevent any further problems for you and the family. Please call me if there are any questions about the operation of the systems and/or any other matters regarding protective security) Many thanks >^ 716 Glenn Robinette & Associates R B 263 LC. Col. Oliver North 703 Kentland Drive Great Falls, Virginia 22066 For Installation of Security Equipment, Systems and Services at 703 Kentland Drive, Great Falls, VA. (This equipment should prevent any further problems for you and the family. Please call me if there are any questions about the operation of the systems and/or any other matters regarding protective security) Many thanks >^ 22 September 1986 Ollle, Due to my schedule I have not found time to follow up on my paper work - as you can - -e from the dates. I'm sure that you have had the same problem. Pl€3se remit when you have tim*. Many thanks I 717 R B 261 L^Col Oliver L. North t 703 Kentland Dr. Great Falls, Va . 22066 18 May 1986 Dear Mr. Robinette -sr^flar"f„' ?-«.f!"f^^"ed your y system ..^ ."^ '° "Polite z syacern at our hn.i«— .■ - f . _ --. .*«w .JL r^e re-ent t^t-k ►'■I "" '^^'^ house in Grea fron home, „, would very"uch Lnrec"'?"^- "'' f"^"^"^ absent. - -cord wu. ..e .er™r -e^Sl-u-^ri: o:r 'LsTm^:?!^,-- If 13 my understanding that th« f,,ii thft^^'^K^*^^ 58000-8500; thit it can'h""° "'^^ "" "" "• ""' ^-° --°" ^" "--"i" ^o!'?^^''?he^-=--,:- 1. Loan of the equipment for > n.-j j expiration of my active service ^f„?? "?'^° '""'^ ^he Corps (June 1988) at wh?^h ► *^**" United States Marine available for commercial -nHli"" "® "'^^ '»*'<• 0"r home equipment withouriee; or """ °^ ^'""^ ^^^ "d the 2. Payment in full ?«- ..w installation in zi eaual Ln?^,'^"""' '"" '"" "" °f the date that the inlt^lUtion LV""T"'' "^^"cing on operational. -i-iation is completed and fully Given our current financial alternative if this is st ill%menlh?r' ►"* """^"^ prefer the first particularly concerned :;oi t^^a ^roPthe^K^f^- ' '" unfortunate media visibility my oositiL h =hildren given the aforementioned terms are stiu acr.nt k? " g«"era(ed. If the to have you commence work as son^ ! " ^°" ' "« """ll ii^e course, prepared to ^ign an endorse P""'"!'" "• are, of require more than t'^i-'let ?er'"L°l:StcIt L°n"or;ur°rnt^'nr •^•vb^ Oliver L. North 718 264 "iivjr L. North 703 KjntUnd Dr. Falls Chjrch, Va. 2206S O-jar Gljnn, c»ll«- -'" '° '"-'P ""»i"3 -.ach oth.r on pho;^: Tha Sjpc yodr company and thv -.qjip„.^nt „h 1 =°°«"-^ =■<: " 1 ^ndorsara-.-nt of - school, and XaU ,oln, .tTryl.t^'lZ'.-Vl'.ll't lUl^l'^'^ Plaasj advisj soonasc. i dop't wanr «« . . ,. I don'c -anc to hava to rasort trh^n? " "'■' ="''5''"= '"o" " bu -ay homa from work at night "th!r^' "^ '" stations on ™y 719 UNITED STATES DISTRICT COURT =-FOR THE DISTRICT OF COLUMBIA SENATE SELECT COMMITTEE ON SECRET MILITARY ASSISTANCE TO IRAN AND THE NICARAGUAN OPPOSITION The United States Senate Washington, D.C. 20510, Applicant. Misc. No. 87 -OLi- ORDER Upon consideration of the application by the Senate Select Committee on Secret Military Assistance to Iran and the Nicaraguan Opposition, and upon determining that the procedural requirements set forth in 18 U.S.C. S 6005 have been satisfied, it is, this 15th day of June, 1987, ORDERED That Glen A. Robinette may not refuse to testify, and provide other information, at proceedings of the Senate Select Committee on Secret Military Assistance to Iran and the Nicaraguan Opposition, on the basis of his privilege against self-incrimination, and it is FURTHER ORDERED That no testimony or other information compelled under this Order (or any information directly or indirectly derived from such testimony or other information) may be used against Glen A. Robinette in any criminal case, except a prosecution for perjury, giving a false statement, or otherwise failing to comply with this Order. United States District Judge 720 V-^ UNItED STATES DISTRICT COURT '* FOR TITE district OF COLUMBIA SENATE SELECT COMMITTEE ON SECRET MILITARY ASSISTANCE TO IRAN AND THE NICARAGUAN OPPOSITION The United States Senate Washington, D.C. 20510, Applicant. Misc. No. 87- APPLICATION FOR ORDER IMMUNIZING TESTIMONY AND OTHER INFORMATION PROVIDED BY GLEN A. ROBINETTE 1. The Senate Select Committee on Secret Military Assista-nce to Iran and the Nicaraauan Opposition applies to C-r- this Court for an order, pursuant to 18 U.S.C. SS ^OOi l?uJ _ - ■';; -^ ' 6005, immunizing from use in prosecutions testimony, and other ^ information provided by one of its witnesses. Glen A. ^ "2 Robinette, at proceedings of the Select Committee. "^ 2. Senate Resolution 23, 100th Cong. 1st Sess., 133 Cong. Rec. S575-78 (daily ed.. Part II, Jan. 6, 1987), established the Select Committee and authorized it to conduct an investigation into transactions to provide arms to Iran and into the use of the proceeds from those transactions. 3. Senate Resolution 23 authorizes the Select Committee to hold hearings, conduct depositions and require answers to interrogatories; issue subpoenas for obtaining testimony and documents; and apply for immunity orders under 18 U.S.C. SS 6002 and 6005. 721 »-«*■ ..i^^^it^ 4. q^-.tfune 4, 1987, by a unanimous vote of its eleven members, the Select Committee adopted a resolution directing the Senate Legal Counsel to apply for an order immunizing testimony and other information provided by the witness at proceedings of the Select Committee. The Select Committee's resolution is attached as Exhibit A. 5. It is anticipated that the witness will invoke his constitutional privilege against self-incrimination. 6. In accordance with 18 U.S.C.$ 6005 and 28 U.S.C.
S 594(a)(7), we notified Independent Counsel Lawrence E..
Walsh on June 4, 1987, of the Select Committee's intention to
request this order. A copy of the notice to the Independent
Counsel is attached as Exhibit B. On June 4, 1987, we also
notified the Attorney General of the Select Committee's
intention to request this order. A copy of the notice to the
Attorney General is attached as Exhibit C. A certificate of
service of Exhibits B and C is attached as Exhibit D.
7. We have been authorized to represent to this Court
that neither the Independent Counsel nor the Attorney General
will request this Court, under 18 U.S.C. S 6005(c), to defer
the issuance of an immunity order for this witness.
722
723
'^J i--Tj|&&^-'^
a 'ts ••( «i)niM?.iiM S
■: ••='»r;-JT!iE.SAFECEn ^
^
■» 5^
724
•^t^
Oliv-r L. North
703 K.-ntland Dr.
Falls Church, Va . 22066
1 Occ 86
D-.-ar Gl-jnn,
security arrang-.mvnts at th-' hoas-! r T ^^^ Pl'-'^'-'d with th-.
looking in on B-tsy and th-- cirlc'' .k" H^° Srat-.^fal for your
school and .y h.ctlc ..cT^ol^'^l^^^tl t^^^'l^^.^'l ,\\
^^rlt.^^i^- wn:.r^V°J ^l^^^ f .. It was our
option for r-.i,„bursvm-..nt - ?hat is !L ^-'^^ T"^ "^'^ ^^""^
your company and th-.- --quipm'nt wh!; ""™;'^=ial -'ndors-.^m-.nt of
Corps in 1988. if chat il n^l r-tir- from th-.- Marin-
no3.th-..r and talk Shil " w- a%r;;.%^"^:"""<^i"3, --' ----'^ to g.t
- school, and Xait going n^^^'^^Vl' ^ lUiJ^r^
:'^:n.t^2rirtn;;r;o ;-^o;:\rh:ir ^° '■- =°^^^^ -°" - -^
way hom-.^ from work at night lit J°r^^ ^^ ^^^ stations on my
Warm regards.
6x. G'R- /c;^
t/.7/?7 r?*
725
LtCol Oliver 1. North, USNC
'03 Kentland Dr.
Great Falls, Va. 22066
18 May 1986
Dear Mr. Robinette
KstlfraMon^fTsl°u"L'frsysr:rae^".^°J^^^ ^° %^P«^^- ^^«
I. Loan of th«
?;j!n!t! '"-^"ii ^°^ '^^ equipment and the cost of
the dite thrt\"H •^''"^^'"°"'^^^ increments commencing on
oSeratiJnIj! ''' ^"«^-ll"^on is completed and full/
Given our current financial situation, we would prefer the first
ni't"''^'^? '^ '^^' ^" ^''^^ amenable to your companj! I am
particularly concerned about the saf^tv of i-h« ^hiT^ ■
unfortunate media visibility ;y%::f;;o^1argen%' e"? ^^^th:'^
tn h.^! ^"^'^ '*™^ "^ ='^^^ acceptable to ?ou , we would 1 ke
rnu.tl ^^^ commence work as soon as possible! We are, of
course, prepared to sign an endorsement contract now if vou
require more than this letter as indication ofour intent
Oliver L. North
7M
t.jn(?i
726
I Glenn Robinette & Associates
WASHiNcrroN oc 2001s
2 July 1986
Lc. Col. Oliver North
703 Kentland Drive
Great Falls, Virginia 22066
For Installation of Security Equipment, Systems and
Services at 703 Kentland Drive. Great Falls, VA. 58,000.00
(This equipment should prevent any further problems for
you and the family. Please call me if there are any questions
about the operation of the systems and/or any other matters
regarding protective security)
Many thanks I
727
Clinn Kohinette & Associates
WASHINCTON DC ^15
2 July 1986
Lc. Col. Oliver North
703 Kencland Drive
Great Falls, Virginia 22066
For Installation of Security Equipment, Systems and
Services at 703 Kentland Drive, Great Falls, VA. $8,000.00 (This equipment should prevent any further problems for you and the family. Please call me if there are any questions about the operation of the systems and/or any other matters regarding protective security) Many thanks 1 >^ 22 September 1986 Ollie, Due to my schedule I have not found time to follow up on my paper work - as you can see from the dates. I'm sure that you have had the same problem. Please remit when you have time. Many thanks 1 728 \,'-V CARDKEY SecurO^iCyatems OORO-MATIC Automatic Doori STANLEY Parking Gate & Fence Controls 6Bfe — '-'^^^ — ^^^^ Bait. 301.7< 132 Washington Boulevard Laurel. Maryland 20707 Bait. 301-792-4090 Wash. 301-953-7900 Automatic Door Specialists HOK3SAL SUBUITTtO TO Glenn Robinette and Associates 3365 Arcadia Place, NW 966 - 5873 L5S5_.. Private Residenrp nr. STATE «No ZIP coot Washinton. D.C. 20015 Kentland Drive, Great Fall' OATl Of Pt«i Automatic Door Specialists (ADS) will automate the existing gate using an Edko Medium Duty Swing Gate Operator. To accommodate automation of gate, ADS will remove existing wooden gate post, replace it with a metal post painted white. In conjunction with automation of the gate, ADS will provide one Multi-Elmac Receiver and two Multi-Elmac Single Button Transmitters to operate gates from an automobile. ADS also will install an Aiphone Intercom consisting of an IBG-IGD Master Station inside the front door, and IBG-IHD Additional Master on the upstairs bedroom, and an IB-DA Door Station on a post outside the gate. I ADS will install intercom wiring through existing conduit and will obtain power from existing box in the yard near the gate location. Quoted price doesnot include price of permits, if needed. ^^^^C^ GUARANTEE - Material & Equip. - 1 yr. Labor - 3 mo. Br ^ropOBr hereby to furnish material and labor — complete in accordance with above specificaions . tor the sum ot Two thousand one hundred fifty-four 2,154.00 Plymant to b« made as follows: U discount / 20 day. Net 30. A 1% service charge will be charged 30 days after the date of the invoice. •n \ Cofnp^fiMdc l^rpptanrp of PrapoBol -tm. ao and conditions are satisfactory and are hereby accep Oalt ol Accaoiance ff?'* jAtf^t.^^. '' T^ -A 729 SPECIALISTS imOTOM sou • ••0 JO'O' July 7, 1986 Glen Robinette and Associates 3265 Arcadia Place, NW Washington, DC 20015 Dear Mr. Robinette: Attached is an invoice for$ 2,173.00. This amount represents the
original $2,154.00 contracted for. plus$ 19.00 for an additional radio
transmitter.
Mr. Robinette, Automatic Door Specialists appreciates the business
represented by this invoice. If we may provide additional assistance to
you in the future, please do not hesitate to contact me.
Very truly yours,
AUTOMATIC DOOR SPECIALISTS
730
^«f '^^
AUTOMATIC DOOR SPECIAIISTS
IjrWtSNINfiTONIOntVAlO
UUIB, MAITUM 20707-4397
2764^- -r
JOS INVOtd
DOOR CONTROU
SfcuRnr CAios
rARKINO GATfS
Glman Robln«ct« aod AaBociates
^Tll^
is.uii ',^a, D.
Prlvf KMid«Qc«. K>n tland Drlv.. fir>^,; f ,;| „ y^
731
LAUREL. MARVLMC 20707 --^*-
PYMT RcvD
u ir^ \v^ ls
3166
Vasninaton. D.C. 20015
X. — ftlarm System Anr^ . ^^ r ^ ] ,t,
J-: Electrical Work.
06/20/86
J369
Kent land_Drive_ Proper c Y_
Materials
Net -- 30
gj.oa;
1.25(
2,88( 00
SUB-rOTAL
^ess Down PYll^
TOTAL DUE;
? 7.567
4.136
$11.703 ? -^.'^l '^Mufyow ufo(f7 77^ 732 vATET.. INjC^Q^^ Zn\-ED \ZZ LA'FAYeTTE AVENUH! LAUREL. MD 20707 9 5 3 O057 KR. GLENN ROBINETTE 3265 ARCADIA PLACE, N.W. WASHINGTON, D.C. 20015 JULY 10, 198 6 DEAR MR. ROBINETTI COFt PER YOUR REQUEST, THE, FOLLOWING IS A SIMPLIFIED TECHNICAL EXPLAINATION OF THE SYSTEM DESIGNED AND INSTALLED BY "VATECINC AT THE NORTH RESIDENCE IN THE GREAT FALLS AREA OF FAIRFAX COUNTY VA. IN ORDER TO MEET SOME SPECIAL REQUIREMENTS WE BOTH FELT WERE NEEDED TO ENHANCE THE PROTECTION OF THE AFORKENTIONED PROPERTY, I DESIGNED AND ENGINEERED A SYSTEM TO DO CERTAIN OPERATIONS BOTH MANUALLY AND AUTOMATICALLY. THE BASIC SYSTEM CONSISTS OF A WIRELESS !-JLr.?r. SYSTEM WHICH PROTECTS THE HOUSE EY DETECTING UNAUTHORIZED ENTRY AND MOVEMENT WITHIN THE HOUSE WHILE ARMED. THE HOUSE IS ALSO PROTECTED FROM FIRE BY THE INSTALLATION OF THE "SMOKE DETECTORS". OUTSIDE LIGHTS, USING THE LATEST ADVANCES IN TECHNOLOGY, WE.RE INST.ALLED TO INCREASE THE PROTECTION. IT IS A WELL KNOWK FACT THAT THE GREATEST DETERANT TO BURGULARS AND VANDALS ETC., IS THE PRESENCE OF LIGHT. THESE LIGHTS ARE ARRANGED SO THAT THEY CAN BE USED FOR CONX^NIENCE AND ARE CONNECTED SO THAT AN ALARW BY THE SYSTEM TURNS ALL LIGHTS ON UNTIL THE AI,ARM IS TURNED OFF BY THE OWNER. THE SYSTEM IS ALSO CONNECTED BY THE PHONE TO A CENTRAL STATION WHICH CALLS THE PROPER AUTHORITIES WHEN THERE IS AN UNAUTHORIZED ENTRY, FIRE OR OTHER KIND OF EMERGENCY SITUTION, 3Y SPECIAL ELECTONIC CODE. I ALSO HAD A SPECIAL ELECTRICAL CIRCUIT INSTALLED AT THE FRONT OF THE PROPERTY NEAR THE GATE TO PROVIDE A MEANS BY V.-HICH VARIOUS CEVICES COULD BE OPERATED BY STANDARD "AC" LINE VOLTAGE. I MADE SURE 3Y MY SPECIFICATIONS THAT CERTAIN SAFETY PRECAUTIONS WERE INCORPORATED SO AS TO MAKE THAT CIRCUIT MORE RELIABLE. THE WORK ALSO INCLUDED THE INSTALLATION OF A SIREN IN ONE VEHICLE TO BE USED AS A DISTRESS SIGNAL. t/.7/f9 JUi 733 IN THE ONITED STATES DISTRICT COORT -- FOR. THE DISTRICT OP COLUMBIA HOOSE SELECT COMMITTEE TO INVESTIGATE COVERT ARMS TRANSACTIONS WITH IRAN O.S. House of Representatives Washington, O.C. 20515 Applicant. ORDER Misc. NO. S7- ^'^ FILED JUN 1 5 1937 CLE'JK. U. S. DISTRICT COURT DiSTRICT OF COLUMBIA On consideration of the application by the House Select Committee to Investigate Covert Arms Transactions with Iran and the memorandum of points and authorities, and exhibits, in support thereof, the Court finds that the procedural requisites set forth in 18 U.S.C. S 6005 for an order of the Court have been satisfied. Accordingly, it is ORDERED that Glen Robinette may not refuse to provide any evidence in proceedings before the House Select Committee to Investigate Covert Arma Transactions with Iran on the basis of his privilege against self-incrimination, and it is FORTHER ORDERED that no evidence obtained under this Order (or any information directly or indirectly derived from such evidence) may be used against Glen Robinette in any criminal case, except a prosecution for perjury, giving a false statement, or otherwise falling to comply with this Order. ■1- 6^. G-^-ilA 734 FURTHER OabBRED That this Order shall become effective June IS, 1987. Onrlted States District '5ud Onrited States District '<fudge Dated: June 15, 1987 -2- Unlted States District Court tor th» District or Coluxbu A THUS COPY JAMES r. DAVSy. rLIRK. Deputy Cler^ 735 Wher^Te, the Select Committee respectfully requests that this Court issue an order immunizing from use in prosecutions testimony and other information provided by Glen A. Robinette at proceedings of the Select Committee. Respectfully submitted. Of Counsel: Arthur L. Liman Paul J. Barbadoro Mark A. Belnick UDu.. Michael Davidson Senate Legal Counsel Ken U. Benjamin, Jr. Deputy Senate Legal Counsel Morgan J. Frankel Assistant Senate Legal Counsel Susan B. Fine Assistant Senate Legal Counsel 642 Hart Senate Office Building Washington, D.C. 20510 (202) 224-4435 Counsel for Senate Select Committee on Secret Military Assistance to Iran and the Nicaraguan Opposition Dated: June 15, 1987 736 UNITED "-STATES DISTRICT COURT FOR THE DISTRICT OF COLUMBIA SENATE SELECT COMMITTEE ON SECRET MILITARY ASSISTANCE TO IRAN AND THE NICARAGUAN OPPOSITION The United States Senate ) Misc No Ri-J}*f Washington, D.C. 20510. ^°- ^^-fSU Washington, D.C. 20510, Applicant MEMORANDUM OF POINTS AND AUTHORITIES IN SUPPORT OF APPLICATION FOR ORDER IMMUNIZING TESTIMONY AND OTHER INFORMATION PROVIDED BY GLEN A. ROBINETTE The Senate Select Committee on Secret Military Assistance to Iran and the Nicaraguan Opposition is applying to this Court for an order immunizing testimony and other information which will be provided to it by one of its witnesses. Glen A. Robinette. The application is presented pursuant to 18 U.S.C. § 6005 which provides, in relevant part: S 6005. Congressional proceedings. (a) In the case of any individual who has been or may be called to testify or provide other information at any proceeding before either House of Congress, or any committee ... a United States district court shall issue, in accordance with subsection (b) of this section, upon the request of a duly authorized representa- tive of the House of Congress or the committee concerned, an order requiring such individual to give testimony or provide other information which he refuses to give or provide on the basis of his privilege against self-incrimination, such order to become effective as provided in section 6002 of this part. (b) Before issuing an order under subsec- tion (a) of this section, a United States district court shall find that — (1) * * * * 737 (2) in the >case of a proceeding before a committee or a subcommittee of either House of Congr^^»- . . . the request for such an order has been approved by an affirmative vote of two-thirds of the members of the full committee; and (3) ten days or more prior to the day on which the request for such an order was made, the Attorney General was served with notice of an intention to request the order. (c) Upon application of the Attorney General, the United States district court shall defer the issuance of any order under subsection (a) of this section for such period, not longer than twenty days from the date of the request for such order, as the Attorney General may specify. This law provides the mechanism by which a witness before a congressional committee receives "use immunity" for testi- mony. The immunized witness remains subject to prosecution for the transactions ajsout which he or she testifies if the govern- ment sustains the burden of proving at trial that it did not use the immunized testimony or its fruits in the prosecution. See Kastigar v. United States , 406 U.S. 441, 459-62 (1972). Because the court's inquiry on an application for an immunity order is narrow and its tests are mechanical, the application may be decided ex parte without a hearing. Ryan v. Commis- sioner of Internal Revenue , 568 F.2d 531, 540 (7th Cir. 1977), cert, denied , 439 U.S. 820 (1978). Section 6005 sets out the two requirements for an immunity order, both of which have been met.i' First, "in the case of a 1/ The Select Committee may apply for this order prior to summoning the witness to testify or provide information at one of its proceedings. In re Application of United States Senate Permanent Subcommittee on Investigations (Cammisano) , 655 F.2d 1232, 1236-38 (D.C. Cir.), cert, denied, 454 U.S. 1084 (1981). 738 proceeding before a conunittee ... the request for such an order has been ap^oved by an affirmative vote of two-thirds of the members of the full co'mmittee. " 18 U.S.C. § 6005(b)(2). The Select Committee's resolution (Exhibit A to the application), shows that the Committee approved this request for an order by a unanimous vote of its eleven members on June 4, 1987. Second, "ten days or more prior to the day on which the request for such an order was made, the Attorney General was served with notice of an intention to request the order." is U.S.C.$ 6005(b)(3). Under 28 U.S.C. $594(a) and (a)(7), an independent counsel has, for all matters within his prose- cutorial jurisdiction, "full power and independent authority to exercise all investigative and prosecution functions and powers of the ... Attorney General ... includ(ing] ... for purposes of sectionO ... 6005 of title 18, exercising the authority vested in ... the Attorney General." The testimony and other information sought to be compelled from the witness is within the investigative and prosecutorial jurisdiction that the special division of the District of Columbia Circuit has vested in Independent Counsel Lawrence E. Walsh. In re Oliver L. North, et al.. Div. No. 86-6 (D.C. Cir. Division for the Purpose of Appointing Independent Counsels, Dec. 19, 1986). The accompanying certificate (Exhibit D) shows that Independent Counsel Lawrence E. Walsh was served with notice of our intention to request this order (Exhibit B); notice to the 739 Independent Counsel was ^iven on June 4, 1987, which is "ten days or morej>tior to" today.!/ Accordingly, the Select Conunittee requests that the Court issue an order inununizing the testimony and other information which Glen A. Robinette will provide at proceedings of the Select Committee. Respectfully submitted, Michael Davidson Senate Legal Counsel Ken U. Benjamin, Jr. Deputy Senate Legal Counsel Morgan J. Frankel Assistant Senate Legal Counsel Susan B. Fine Assistant Senate Legal Counsel 642 Hart Senate Office Building Washington, D.C. 20510 Of Counsel: (202) 224-4435 Arthur L. Liman Counsel for Senate Select Committee Paul J. Barbadoro on Secret Military Assistance to Iran Mark A. Belnick and the Nicaraguan Opposition Dated: June 15, 1987 2/ On June 4, 1987, we also notified the Attorney General (Exhibit C) in the event that he believes that notice should also be provided to him notwithstanding 28 U.S.C. S 594(a)(7) 740 t? f SELECT COMMITTEE TO INVESTIGATE COVERT ARMS TRANSACTIONS WITH IRAN U.S. HOUSE OF REPRESENTATIVES and SELECT COMMITTEE ON SECRET MILITARY ASSISTANCE TO IRAN AND THE NICARAGUAN OPPOSITION UNITED STATES SENATE Washington, D.C. Wednesday, June 17, 1987 The deposition of GLENN A. ROBINETTE, called for examination in the above-entitled matter, pursuant to notice, in the offices of the Senate Ethics Committee, Room 220, Hart Senate Office Building, Washington, D.C, convened at 10:41 a.m., before Pamela Briggle, a notary public in and for the District of Columbia, when were present on behalf of the parties: ^- /( V'^ 741 pb2 APPEARANCES : On Behalf of the Select Committee on Secret Military Assistance to Iran and Nicaraguan Opposition of the United States Senate: PAUL BARBADORO Deputy Chief Counsel KENNETH BALLEN, Staff Counsel JOHN R. MONSKY, Staff Counsel Room 901 Hart Senate Office Building Washington, D.C. On Behalf of the Select Committee t Transactions with Iran of the U.S. Representatives : ) Investigate Arms House of GEORGE W. VAN CLEVE Room H-149, U.S. Capitol House of Representatives Washington, D.C. On Behalf of the Witness: MARK H. TUOHEY, III, ESQUIRE Pierson, Ball & Dowd 1200 18th Street, N.W. Washington, D.C. Also Present: Thomas Polgar 742 pb3 ym C Soot. NX CONTENTS WITNESS GLENN A. ROBINETTE By Mr. Barbadoro By Mr. van CI eve NUMBER GR-1 GR-2A-B GR-3 GR-4A-B GR-5A GR-6A-B GR-7A-F GR-8A-E GR-9A-B GR-IOA-B GR-llA-B EXAMINATION EXHIBITS FOR IDENTIFICATION 743 UNITED STATES DISTRICT COURT — FOR THE DISTRICT OF COLUMBIA SENATE SELECT COMMITTEE ON SECRET MILITARY ASSISTANCE TO IRAN AND THE NICARAGUAN OPPOSITION The United States Senate Washington, D.C. 20510, Applicant. Misc. No. 91- p2J^ FILED JUi\ 1 5 1937 ORDER CLE^'<. u s 0'-"^"^^ COURT DISTRICT Oh- COLUMB^ " Upon consideration of the application by the Senate Select Committee on Secret Military Assistance to Iran and the Nicaraguan Opposition, and upon determining that the procedural requirements set forth in 18 U.S.C. S 6005 have been satisfied, it is, this 15th day of June, 1987, ORDERED That Glen A. Robinette may not refuse to testify, and provide other information, at proceedings of the Senate Select Committee on Secret Military Assistance to Iran and the Nicaraguan Opposition, on the basis of his privilege against self-incrimination, and it is FURTHER ORDERED That no testimony or other information compelled under this Order (or any information directly or indirectly derived from such testimony or other information) may be used against Glen A. Robinette in any criminal case, except a prosecution for perjury, giving a false statement, or otherwise failing to comply with this Order. United States District Cc-jrt for the ris'.T-loc of CjI t:.:^ A^,.:.^ TP.'JS zz.'i '^ " United States Distf.ict Judge JAiES F. :a;jy, Dv^auty Clerlt 744 MICHAEL OAVIOSOM SUSAN S riNC HBtal States Senate lOexMio-riM NOTICE OF INTENTION TO REQUEST ORDER CONFERRING IMMUNITY The Honorable Lawrence E. Walsh Independent Counsel 555 13th Street, N.W., Suite 701 Washington, D.C. 20004 Please take notice that the undersigned, as representative of the Senate Select Committee on Secret Military Assistance to Iran and the Nicaraguan Opposition, will request the United States District Court for the District of Columbia, pursuant to 18 U.S.C.$ 6005 and
2 U.S.C. SS 288b(d) and 288f, to issue an order immunizing
from use in prosecutions the testimony of, and other
information provided by. Glen A. Robinette at proceedings of
the Select Committee.
#.1J
Michael Davidson
Senate Legal Counsel
642 Senate Hart Building
Washington, D.C. 20510
(202) 224-4435
Dated: June 4, 1987
MICHAEL DAVIDSON
<ENU I
745
BnitDl States ^mtt
ofnci Of SiMATt iioAi couNsa
NOTICE OF INTENTION TO REQUEST
ORDER CONFERRING IMMUNITY
TO: The Honorable Edwin Meese III
The Attorney General of the United States
Washington, D.C. 20530
Please take notice that the undersigned, as
representative of the Senate Select Committee on Secret
Military Assistance to Iran and the Nicaraguan Opposition,
will request the United States District Court for the
?\^,'^o^S*^ °^ Columbia, pursuant to 18 U.S.C. § 6005 and
?ro; •' 288b(d) and 288f, to issue an order immunizing
from use in prosecutions the testimony of, and other
ih- c"f''^?V°''''^^'^ ''y' '^^®" '^- Robinette at proceedings of
the Select Committee.
4ichael Davidsc
Michael Davidson
Senate Legal Counsel
642 Senate Hart Building
Washington, D.C. 20510
(202) 224-4435
Dated: June 4, 1987
746
CERTIFICATE OF SERVICE
I certify that on June 4, 1987, in accordance with 18
U.S.C. S 6005(b)(3) and 28 U.S.C. S 594(a)(7), I caused to be
hand delivered to The Honorable Lawrence E. Walsh, Independent
Counsel, and the Honorable Edwin Meese III, the Attorney
General of the United States, notices of the intention of the
Senate Select Committee on Secret Military Assistance to Iran
and the Nicaraguan Opposition to seek an order conferring
immunity upon Glen A. Robinette.
Mu ^.
u..
Michael Davidson
Senate Legal Counsel
EXHIBIT D
747
748
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OF PROCEEDINGS
CONFIDENTIAL
UKITED STATES SENATE
SELECT COMMITTEE ON
SECRET MILITARY ASSISTANCE TO
IRAN AND THE NICARAGUAN OPPOSITION
DEPOSITION OF FELIX I. RODRIGUEZ
■ Declassified/ReleasMl nn QoAiq lAp
under provisions of E.0. 12356
2, Reger, National Security Council
57/ s
Washington, D. C.
Friday, May 1, 1987
UNCLASSlRONRDSmiAt
fUifnjX
Ace-Federal Reporters, Inc.
Stetwtype Reporten
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COPY NO.
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ii 22
UNITED STATES SENATE
SELECT COMMITTEE ON
SECRET MILITARY ASSISTANCE TO
IRAN AND THE NICARAGUAN OPPOSITION
DEPOSITION OF FELIX I. RODRIGUEZ
Washington, D.C.
Thursday, Aoril 30, 1987
Deposition of FELIX I. RODRIGUEZ, called for
examination pursuant to subpoena, at the Hart Senate Office
Building, Suite 901, at 10:35 a.m., before Michael G.
Paulus, a notary public in and for the District of
Columbia, when were present on behalf of the respective
parties:
Deputy Chief Counsel
United States Senate Select
Committee on Iran and the
Nicaraguan Opposition
- continued -
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UNCLASSIFIED
TOM P.foLGAR, ESQ.
RICHARD CULLEN, ESQ.
RICHARD ARENBERG, ESQ.
uwcussiF'in
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GNCLASSIF'.EI
WITNESS
Felix I. Rodriguez
CONTENT
EXAMINATION
EXHIBITS
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i;NCLASS]F:g9
PROCEEDINGS
Whereupon,
FELIX I. RODRIGUEZ
was called as a witness and, having been first duly sworn,
was examined and testified as follows:
EXAMINATION
Mr. Rodriguez, you received a letter from
Colonel North in September of 1985, did you not?
A Yes, sir, I did.
When did you receive that letter, exactly?
A It was dated the 20th and I received it on the
29th.
you have provided the committee with a copy of
that letter, correct?
A Yes, sir, I have.
Can you tell rae in general terms what that
A It was basically to set up a logistical asoect
of the Nicaraguan freedom fighters resupply network. The
letter actually said only to be able to produce maintenance
at the area where I was able to help in Central America.
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INCLASSIFIlD
Q Did this letter ask you to provide storage
facilities for ammunition and humanitarian' aid?
A No, sir. Not at that time.
Q It only asked you to provide maintenance
facilities?
A Right. Space in the area where airplanes could
be serviced on a week basis and two or three different
types of aircraft.
Q What did you do after you received the letter?
A I talked to the proper people that I was asked
to contact and that I knew and had good relations with and
acquired the okay to go ahead and use that area for
maintenance of the aircraft. On the following day I
notified Colonel North over the telephone that it was a go.
Did Colonel North give you any instructions at
that time?
A In the letter he said that the individual who
was going to help me to set this up will call me or contact
mo and identify himself as coming from Mr. Green.
Did you ever receive a call from someone who
identified himself as working for Mr. Green?
A Yes, I did, sir. I received a call, I would
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say, approximately (witness reviewing notebook) — i would
say it was the 14th of December 1985. I received a call in
my room at the air base where I was and the individual that
I knew from before identified himself as coming from
Mr. Green.
Who did you know this individual to be?
A Raphael Quintero.
What did the person say to you in the phone
call?
A He identified himself and then he said if I
could arrange the arrival of a Boeing 707 from Europe —
the way he described it was it was bringing heavy stuff",
and if I could keep it in the area of my responsibility. I
said I would check with the local people and to contact me
later. wWhich he did, and I was able to get the okay from
aircraft with the heavy stuff we had assumed was military
equipment.
Q Did he ask you to provide a facility to store
the material brought in on it?
A Yes. He asked me if it was possible for me to
store it in the area. It was possible in local facilities
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2 When did the aircraft arrive?
3 A The aircraft arrived on the following day, which
4 I believe was on the weekend, a Saturday, and it was a
5 Boeing 707 from Southern Air Transport.
6 Q What did the plane contain?
7 A The plane contained mainly, if I recall
8 correctly, hand grenades, 81 millimeter mortar rounds, 60
9 millimeter mortar rounds, ammunition of different calibers,
10 and perhaps some 40 millimeter rounds. There were several
^ 11 shipments later on. So I am taking all that arrived could
12 have been on that plane. The other three eventually did
13 all arrive with this type of equipment. Some C-4
14 explosives, detonators and primers, etc. It was
15 approximately 88,000 pounds.
16 What did you do with the material that was
17 brought in on the plane?
18 A The material that was brought in was stored in a
19 local facility belonging to a local officer of the area.
20 Did you meet with Colonel North in December of
21 1985 in Central America?
22 A Yes, sir. Colonel North visited the area where
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I was working on a helicopter program, on December 30,
1985, if I recall correctly.
How did he get to Central America?
A He arrived, I believe, in a Jetstar aircraft.
Who was with him?
A My understanding Is It was to coordinate the
legal humanitarian aid approved by Congress, and aboard
that aircraft was^HH^^^L I had known him before when
he was number three man for Ambassador]
^^^^^^H There was^^^^^^^^V, who was from
the agency. During that meeting were also present the
officer, if I recall correctly, andj
and myself. Probably
but I'm not sure.
In general terms, what was discussed at that
meeting?
A If I understand correctly, they were having
problems with being able to bring In humanitarian aid into
secause of some kind of political situation and
they thought of the possibility of temporarily usinq^H
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2 approved by Congress. They wanted to make sure that
3 nothing was stolen or lost and they had to create a balance
4 and check type of situation on everything that arrived and
5 departed from there.
6 Q Up to that point had any humanitarian aid
7 arrived at your location in Central America?
8 A No, sir.
9 At some point after that did humanitarian aid
10 arrive at that location?
11 A Yes, sir. Later on, in the beginning of 1986,
^ 12 there was an LlOO from Southern Air that did carry some
13 Butler buildings to be built for this purpose. And also
14 some humanitarian aid, I believe, came along on the same
15 aircraft.
16 Was that in January of 1986?
17 A To the best of ray recollection, it was January
18 17 when the first flight arrived, and I told you that later
19 on I would provide you with more details.
20 During the entire time that you were down there,
21 that being 1985 and 1986, how many flights of humanitarian
^ 22 aid arrived?
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A I cannot really be sure at that time. There
were not many. Maybe two, maybe less, maybe three. I will
be able to answer that question after I go back to Miami
and look at some notes that I may have, to be accurate.
Where would the humanitarian aid be stored?
A It was supposed to be stored in that warehouse
that was being built, the Butler buildings.
During 1985 and 1986 did more lethal aid arrive
A Yes, sir. In 1986 there were several 707s
coming from Europe, also for Southern Air, that arrived in
the area. At one point two aircraft came in one day after
the other, which I believe to be the 25th and 26th of May.
It was also military equipment, and approximated between
88,000 and 90,000 pounds apiece. Same type of material
In total, how many flights of lethal aid were
A To the best of ray recollection, there were
somewhere between five, probably six, but not much more
than that. I will try to provide more accurate records
later on.
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2 pounds?
3 A Yes, sir. The estimate that we believe we had
4 in the warehouse for military aid did not go over 500,000
5 pounds.
6 Do you recall a meeting again with Colonel North
7 in Central American in April 1986?
8 A Yes, sir. I recall a meeting with the colonel
9 on April 20, 1986.
10 How did Colonel North get to Central America on
11 that occasion?
^ 12 A He was using the same aircraft he had used
13 before, the Jetstar, and he arrived the 20th of April into
14 this friendly country, and he was accompanied by retired
15 General Secord, Dick Gadd, all the members of the crew that
16 had been recruited for the resupply operation. There was a
17 meeting held at that location. ^^^^^Bjfrom the FDN came
18 to discuss the aid to Nicaraguan freedom fighters.
19 What did you understand General Secord' s role to
20 be in this resupply operation?
21 A General Secord seemed to be the individual in
22 charge of all the operation itself as far as personnel was
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concerned and the logistics in the program. He was the one
who controlled the individuals who came on that plane.
discussions with General Secord over the phone.
A Well, I realized later on that I did have a
discussion with the general over the telephone over an
incident of a mechanic that was brought into the area where
I was, a conflicting type of situation.
Can you describe that incident?
A Yes, sir. One day we were called by Mr. Gadd,
if I recall correctly. They gave us a name, which I have
now forgotten, but I am sure that you have it. It Was an
individual who was going to be working for us as a mechanic
in this project. He arrived. We sent a couple of people
to pick him up at the airport. They really could not
recognize the individual, so they returned.
Later on this individual called from the hotel.
When they picked him up they said it was hard to recognize
him because he looked pretty old, that he could be going
into a nursing home.
This individual came to the house that we had
provided for him. The first night he drank 24 beers; the
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^'kepaulus 1 sacond night he drank 36 beers. He told one of our kickers
2 working^ in the project that he was told that this was a
3 money-making operation, that he had fixed one plane in
4 l^mP at one time was doing contraband in Mexico for
5 $5,000 in one night; and he also fixed drug planes in 6 Puerto Rico, from Colombia. point ^°^<^ HBI^BHHv ^h° 8 brought me the information, I didn't even want to meet him 9 or have him know what the operation was about, and tried to 10 prepare his return to the United States on the following ^ 11 day. 12 After that I did call Colonel North, to his 13 telephone in the White House. I started explaining to him 14 the circumstances of this individual and my decision to 15 send him back immediately without further explanation what 16 the program was. He said to me here is the man you have to 17 talk to .about it, who was in charge of that, if I 18 understand correctly. Or similar words. He put on the 19 phone a man he identified as Dick. At the beginning I 20 thought it was Mr. Gadd, but later on I realized he was 21 General Secord. ^22 I explained the situation to the general in a Ace-Federal RS^orte 'ORTERS. Inc. 202-347-3700 Nationwide Coverage unn-UA-^fc. 769 680 01 01 nlkepaulus 1 2 3 4 5 6 7 9 10 11 12 13 14 15 16 17 18 19 20 21 22 gnclassif:eo very strong voice like he has, and he told me he would take care of it. At that point I told hira I was sending this individual back to the states, and he agreed to it. Did the mechanic end up being sent back to the United States? A Yes, sir, and I don't think he ever knew what the operation was all about. Let's go back to the April 20 meeting. What was the purpose of that meeting? A The purpose of that meeting was trying to coordinate with the FDN the support to the north front also and explain to|HHthe use of these aircraft. The TON was apparently very unhappy with the type of aircraft, because of the poor condition of it and low speed of the aircraft, and also the small capability of carrying equipment in it. They thought it was taking a lot of risk in one of these aircraft to resupply their units. It would carry cargo of probably less than 5,000 pounds, and the 12 3 less than 10,000 pounds in reality when you have to fill them up. He explained his concerned and that the FDN fighters were not willing to fly this type of aircraft. He was told by Colonel North that they had Ij^A^'^S^^^^^ers. Inc. ■mi.-ui.-i-IOD Nationwid* Coverige 80O-33«-«646 770 7680 01 01 ^^kepaulua 1 2 3 4 5 6 7 8 9 10 12 13 14 15 16 17 18 19 20 21 GNCLflSS!Fvr> professional people who had done it very successfully In other parts of the world and they would prove to the PDN that these aircraft were adequate for the job and at the present time there would be a U.S. crew flying there, that there were European crews being prepared to come in and eventually train the Nicaraguan pilots to do the job afterwards. When ^mH complained to Colonel North about the condition of the aircraft did Colonel North give an explanation to^^^^H as to where the aircraft had come from? A Yes, sir. WhenJUH^I told the colonel why not give him the money to buy more decent aircraft than these Colonel North explained to him there was no money involved in this transaction, that these aircraft were a donation to the freedom fighters, and that If he had the money he would have bought for them a C-130> since he didn't. It Is better to have this type of aircraft than nothing, and we will provide whatever he was getting as donations from people. Mr. Rodriguez, could you describe what your rol< in this resupply operation was In general terms? mn ORTERS. Inc. 771 ■NCLASSIF'ED 16 7680 01 01 ^'kepaulus 1 A My main thing, which I self-imposed on myself, 2 in the area was to help the local people with the 3 helicopter concept to eliminate the communist guerillas in 4 the area. 5 That was working with the host government; is 6 that right? 7 A Yes, sir. 8 I do strongly support the Nicaraguan freedom 9 fighters after losing my native country to communism, and I 10 was all for supporting Colonel North in the effort to help 11 these people. ^ 12 What support did you give to this effort? 13 A Basically, I was the main liaison with the host 14 government in the area and was responsible for getting ID 15 cards on the base to come in and out, and to coordinate the 16 clearance to leave the air base on the missions and back, 17 and the arrival and departure of material in that area. 18 At some point did you decide to end your 19 involvement with the resupply effort? 20 A Yes, sir, I did. 21 When was that? ^ 22 A That was shortly after this meeting that Colonel n^03cftS&lF^^TE»^' Inc. 202-347-3700 Nationwide Coverage 800-336-6646 772 7680 01 01 W kepaulus 1 2 3 4 5 6 7 8 9 10 12 13 14 15 16 17 18 19 20 21 [UNCLASSIFIED 17 North came to the area. I hate to say* but I had known a lot o£. these people who came to be known to me as time went by in this process, and I was not very happy with the caliber o£ personnel involved in this operation. I felt that the background of these individuals would eventually create a problem not only for the Nicaraguan freedom fighters but for the administration. And that was the reason that you decided to leave the operation? A Yes, sir. Q What did you do when you made this decision to leave? A I went to the host officer that I had originally talked to to help me. I told him that I was tired, that I had been away from my family for over a year, and the program that I was involved in with the helicopters was working properly and I was going to leave. At that point he told me he felt that my presence in the area was important and that I should stay. I agreed with him that 1 would return later on and explain to him all of the details if I finally decided to leave the (Jl'^^jLfi^j^jin 16-' Ace-Federal Reporters. Inc. a)2-347-370O Nationwide Coverage 800-336-«646 773 UNCLASSIFIED 7680 01 01 >cepaulus 1 I "-lent to see the ambassador in the afternoon. 2 He had .no idea that I was involved in the military aspect 3 of it. He knew -that I had participated in the humanitarian 4 aid program. None of this did I express to the 5 ambassador. I just told him the same thing I told my 6 friend, that I was tired and that I had been away from the 7 family too long and I was going to leave the area, and that 8 I was also tired from begging for airline tickets from a 9 friend of mine to be able to commute back and forth from 10 that area. 11 At that point the ambassador saw that I was 12 doing a good job with the helicopter concept in the area, 13 that I should stay. He asked me to stay. He asked me for 14 my address and telephone number so that we could maintain a 15 personal relationship? that he appreciated it the same as I 16 did. 17 I also told hira that I was planning to come to 18 Washington soon to visit the vice president. I had 19 requested the meeting in order to brief him on what I done 20 in a little bit over a year in the area, my results with 21 the helicopter concept, and also explain to the vice 22 president the reason I was going to leave the area. yMQy^iFML 5. Inc. Nationwide Coverue 8<»-3J6^64* 774 bNCLASSIFSED 7680 01 01 i^ kepaulus 1 2 3 4 5 6 7 8 9 10 12 13 14 15 16 17 18 19 20 21 19 Did that meeting with the vice president take Yes, sir. That meeting took place on May 1, Before that meeting you met with Colonel North, place?. A 1986. correct? A Yes, sir, I did. Could you describe what happened in your meeting with Colonel North? A Yes,, sir. I asked to be cleared into the White House a little bit earlier. I basically told him the same thing I had said before. I explained to the colonel that I was tired, that I wanted to leave, and that I was planning to leave at that point in time to express it to the vice president. He told me that my help was very needed and useful in this program and that he knew that all soldiers get tired and I should consider staying; to go ahead and take two weeks vacation but stay in the program. Which I did not agree with, and I said I was still leaving. At that point I left, because my time was getting close to my meeting with the vice president. I came down to the second floor. At the time, if I recall UHfiLASSlM. rERS. Inc. 202-347-37Q0 Nationwide Coverage 80O-336-«646 775 ^UU^^ 20 7680 01 01 m 'tepaulus 1 correctly, the vice president was acting president since 2 president Reagan was in Japan or somewhere. 3 So we went to the other side of the White House, 4 Mr. Gregg, Sara Watson, his assistant, and myself, and we 5 met the vice president, who was with Nick Brady, former 6 senator. He told me he wanted the senator to stay since he 7 was very much interested in Central America and had been on 8 the Kissinger Commission. 9 So we had the meeting from approximately 11:30 10 in the morning until 12:00 noon. 11 In that meeting did you describe what you had ^ 12 done in implementing your helicopter concept? 13 A I explained to the vice president from the 14 beginning of my arrival in the area the problem I 15 confronted in establishing my concept until I had the good 16 luck of capturing ^^I^H^^^H, and from then on had a 17 lot of support from the local individuals. I explained to 18 hire the statistics that I had been given on the reduction 19 of the guerillas since I had been in the area and how good 20 the concept was going. 21 I also brought an album with pictures on the 1^ 22 concept that I was doing with helicopters, etc. ^^yssifS Reporters. Inc. Nitionwidt Coveraic 776 7680 01 01 ^'Icepaulus 1 2 3 4 5 6 7 8 9 10 11 13 14 15 16 17 18 19 20 21 ^ 22 UNCLflSS!F"EO 21 In the middle o£ that meeting one o£ his aides came and requested thatH^^^^^^^^^Hwanted to step in for a moment to say hello. The vice president said that he was already late for another appointment, but this individual insisted. So he said only for a short time. The Ambassador came in accompanied by Colonel North. Colonel North stayed in the background. The ambassador said hello to all of us and then asked the vice president to use his influence in getting me to stay! He explained to the vice president he was very happy with what I had done there, and as long he was arobassador^^^H ^l^^^^ffor me to stay in there and continue to help. Had you told the vice president that you were planning to leave at that point? A No, sir, I didn't. So I really believe that the vice president didn't know what the hell he was talking about. I guess we all have feelings, and I, of course, felt good that the ambassador would do that, and I made the mistake of not following through with my decision. I didn't mention emything to the vice president. I want to make sure to stress that at no point in time did I mention to the vice president anything else Ace-Federal Reporti Reporters, Inc. Nationwide Coverage 800-336-6646 777 yNOLASSiKtiD 7680 01 01 22 <cepaulus 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 that I was involved in. 0^ You didn't tell him anything about your efforts with the resupply? A Not to him. Only a member of his staff. So you decided at that point that you would continue to work in Central America? A Yes, sir. I figured out that eventually the agency would take over this project and the best thing that could happen is that it would be gone and the agency would take care of the operation and that would be the end of this program. So you returned to Central America and continued to work with both the host government in implementing your helicopter concept and with the resupply operation as a liaison to the host government; is that right? A Yes, sir, I did. Did you attend a meeting in the Old Executive Office Building with Colonel North in June 1986? A Yes, sir, I did. June 25, 1986. Q How did that meeting come about? A I was called in the area where I was in Central American on June 23rd by Mr. Quintero, and he told me they u^La^sjfm 5, Inc. Nationwide Coverage 800-336-6646 778 UNCLASSIFIED 23 7680 01 01 " -kepaulus 1 were reorganizing the whole program and they wanted me to 2 go up to Washington on the 25th for a consultation with 3 Colonel North and Mr. Dutton. 4 Did he tell you why they were reorganizing the 5 program? 6 A He just mentioned they were reorganizing the 7 whole thing. He didn't quite go into detail. 8 What happened when you got to Washington? 9 A I talked to Mr. Dutton on the 24th, in the 10 evening, and we agreed to meet at the Marriott Hotel on the ^ 11 25th, about 11:30, if I recall correctly. We had the . 12 meeting with Colonel North from 12:00 noon in the White 13 House. So we went to the White House. 14 On ray way there I was curious to find out from 15 him who actually brought him aboard this program, so I 16 asked him before we got into the White House door. He told 17 me that, it was General Secord. 18 He was cleared immediately and mine was 19 delayed. I don't know if it was done purposely or not. 20 That is, your clearance to get into the Old 21 Executive Office Building? 22 A Yes, sir. UNQl^ira TERS. Inc. Nationwide Coverage 779 7680 01 01 Mp^kepaulus 1 2 3 4 5 6 7 3 9 10 11 13 14 15 16 17 18 19 20 21 22 I also had requested a clearance, since I was in Washington, to go into the White House at 1:30 in the afternoon in order to be able to pick up some pictures that were taken on May 20th between a general friend of mine and his wife with the vice president. They asked me to come around at that time. So I called my friends up there to get me cleared since ray clearance was being delayed already for about 10 or 15 minutes. So I went with Mr. Dutton to the third floor, to a new office that I didn't know, that Colonel North had moved into. And that's where we had the meeting. What happened at the meeting? A When we first came in Mr. Dutton gave me the pamphlet or paper that he had done with the organization of the program. Can you describe what was on that piece of paper? A It was sort of a nice organization of the whole resupply network with names and coordinators and supervisors. It looked very organized. And my role in that was a liaison between his group and the host government in the area. \cE'-hEDERAL Reporters. Inc. Nationwide Coverage 780 7680 01 01 ^ikepaulus 1 2 3 4 5 6 7 8 9 10 11 13 14 15 16 17 18 19 20 21 A. 22 UNOLASSIFIcO 25 This was a diagram of the structure of the operation; is that right? A A diagram of responsibility for every post. And you were listed as the liaison to the host government on that diagram? A Yes, sir. What did you do when you were presented with the diagram? A I smiled and I gave it back to him. What was your reaction when you saw what they had envisioned for you on this diagram? A Not much. My speculation was that they thought the Congress was going to approve the aid to the Nicaraguan freedom fighters and they were preparing a schematic for an operation running and going and trying to get a contract from the Central Intelligence Agency to provide part of the resupply to the Nicaraguan freedom fighters. Had you heard any discussion among the employees of the private benefactors about the possibility that the CIA would contract out this service to this organization? A Yes, sir. Most of the pilots were very confident that they would get the contract to continue with m. Inc. ationwide Coverage 781 7680 01 01 ^^1 kepaulus 1 2 3 4 5 6 7 8 9 10 » ;: 13 14 15 16 17 18 19 20 21 ^ 22 UNCLASSIFKO 26 the program if the Congress approved — like it did — the aid to the Nicaraguan freedom fighters. Q What happened next in that meeting? A We went into a meeting between Mr. Dutton, Colonel North and myself. Colonel North started by telling me ~ he referred to Mr. Dutton as Bob — "Bob here has told me that you have been very helpful to the crews down there and the pilots have suggested that you become part of this organization. So we have suggested that in your role as liaison you be paid$3,000 a month." To which I
explained to the colonel that I was retired and I was not
able to receive a salary per se. Only operations
expenses.
He also told me right after that that he wasn't
too sure that could be done, even me being the liaison,
because he had information that I was a security risk, that
I used to talk too much over the telephone, on open lines,
and also on an amateur radio that I had in my area in
Central America.
Q What did you tell him when he told you you were
a security risk?
A If you will excuse my wording, sir, I told him
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that if he thought I was a security risk he can stick this
goddam operation — fuck it. I didn't want a goddam thing
to do with. And I asked him to show me where I had been a
security risk in all of this. He explained to me that the
Freedom of Information Act prohibits people from releasing
names, etc. So I asked him how he learned about it. He
said, well, there is only one American in the area who
talks over the telephone that we know of and who has an
To that I told the colonel that I would sign to
him a release from the CIA, from the FBI, from the National
Security Agency, and the National Security Council where
they will have access, and even if they wamt to publish in
the past, in the present and in the future any
conversations I might have had over the telephone or any
other means that would prove I have been a security risk or
put in jeopardy any operations I have participated in.
To that he lowered his face and he made some
notes, and he didn't mention about that anymore.
What happened then?
A During the conversation Mr. Dutton mentioned
that he had $1.5 million with which he had to buy one Ace-Federal Reporters. Inc. 202-347-3700 Naiionwide Covenge 800-336^646 783 7680 01 01 W kepaulus 1 2 3 4 5 6 7 8 9 10 11 13 14 15 16 17 18 19 20 21 k 22 Unclassified 28 aircraft. We had to be careful not to spend too much money, ^because the money would also have to take care of all the maintenance for one year of the program, and salaries and all expenditures to run the program for one year. At one point in time I told the colonel that I wanted to talk to him alone. He was looking at the hearings that were taking place that day. Actually, my understanding is during that day eventually the aid to the Nicaraguan freedom fighters was approved by Congress, the$100 million. He looked at the TV and he said "Those
people want to get me, but they cannot, because the Old Man
loves my ass."
When he pointed to the TV set Congress was on
the TV?
A Yes, sir. They were discussing the Nicaraguan
freedom fighters aid.
I told him I wanted to talk him privately. I
had learned through other sources — I don't know whether
it was true or not, but I had reason to believe it could
have been true — that a boat had arrived in|
before that and that the manifest was retrieved by the
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^<kepaui*J* jH^I^^H^^^^^^Hand they were
2 grenades In there for the Nlcaraguan freedom fighters that
3 were bought at $3.00 apiece and being sold to them at$9.00
4 apiece. The gentleman who was supposed to receive the
5 money for that was Tom Kline.
6 At that point I sort of recognized the part of
7 the old group of Mr. Wilson, with whom I used to friends
8 many years before. I had separated for ideological reasons
9 in 1979. I explained that to Colonel North. I actually
10 told him when we were alone, "Look, colonel, you will never
11 find any guy more dedicated or honest than I am in this,
^ 12 but there are people stealing here. My understanding is
13 there are hand grenades being bought at $3.00 apiece and 14 sold for$9.00, and it amounts to 100,000 hand grenades.
15 This is going to be worse than Watergate and is going to
16 des troy the President of the United States."
[7 To that, he told me it was not true, that Mr.
18 Kline was a patriot, that he was not buying any type of
19 equipment; they were all donations, and he didn't touch any
IP money in that.
2yTi I also explained the age of some of the 81
/22 millimeter rounds that were built in 1952 or 1954. They
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were very old. He told me that when they were a donatioa
he could not control the age of it.
He also explained to me if I said this to
anybody they would deny it, that he did carry a letter from
the President of the United States to the Government of
I where he requested the rate, and all of these
materials f rom^^^^^| are a donation and we didn't pay a
cent for it. Since I have been told by a lot other people
that we were buying the equipment, at that point I decided
I better terminate the conversation, which I did.
At some point during that meeting did you
discuss a letter that you had brought with you concerning
the condition of the aircraft?
A Yes, sir. There was an incident with one
C-123. Almost everybody got )tilled because of poor
navigational equipment.' They were off ten miles south in
territory going toward a mission and they hit
the top of a mountain. They actually had wood inside one
of the engines, which was completely destroyed, and there
was damage to the bottom of the 123 aircraft.
Right after that Copilot HJ^P^rote a very
emotional letter explaining all the problems with the
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aircraft and the special situation of why he got involved
in that operation, by pride, but it would never happen
again. It was a very emotional letter that I got a hold
of, and I gave it to the colonel.
Was Mr. Dutton in the room when you gave the
letter to Colonel North?
A Yes, sir, he was. When the colonel was reading
the letter he looked at me and said, 'This is a joke." I
said, "No, sir. I don't think it is a joke when almost all
of those people got killed the day before they wrote that
letter."
He showed the letter to Mr. Dutton and asked him
if he knew anything about it. Mr. Dutton told him that,
yes, he knew but he didn't feel it was important to bring
it to his attention.
Colonel North told him that this type of
situation if given to the press would create a helluva
problem for the program, to which Mr. Dutton answered that
who was the one who wrote the letter, had been
promoted to chief of maintenance for the program and his
salary had been increased tremendously starting the next
month and he would not pose a problem.
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Mr. Rodriguez, at some point in August you used
a plane to fly from Miami to Central America and as a
result oC that flight you were accused of air piracy. Can
you explain that incident for us?
A I'll try, sir. Just before the last part of
July or the very beginning of August I had I
^^^^^1 friend of mine who stayed at my house who wanted me
to stop by to say hello. So I took the opportunity that a
friend of mine was flying on a private aircraft from where
I was to Miami. I had the understanding from the pilot
that was in this operation that a C-123 was being prepared
This was one of the private benefactor 123s?
A Yes, a 123 that was stationed at Southern Air
Transport.
So I flew to the Miami area and spent some time
with my family and]m^H||. I discussed on that
weekend with Mr. Quintero that I was planning to fly this
aircraft back to where I was. I believe it was on the 4th
of August.
Mr. Quintero explained to me that there were
some medicines for mountain leprosy that had to be waited
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upon to be flovm into our area. It was meant for the
Nicaraguan freedom fighters.
My understanding from previous conversations was
this was just a big box and that it could have been sent
locally, and to me it was big waste to hold a C-123 loaded
with spare parts that were badly needed down there, and the
expenditure of the crews and the hotel just for that box.
I explained that to Mr. Quintero. Mr. Quintero told me it
was not just a case of a box, but that it was a half plane
full of medicines.
At that point I called Mr. Gene Stevenson from
Southern Air and explained to him the situation. He told
me that they had enough spare parts, or close to enough
spare parts, to fill a C-130 to our area. He said he would
consult with Mr. Langton from Southern Air. He thought it
was more convenient to go ahead and make the flight that we
medicine arrived it would be cheaper for the program to
lease a C-130 from Southern Air and fly the rest of the
maintenance equipment that we had waiting there plus the
medicines into our area.
So I asked him to make sure to clear it, and he
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So we did depart on the 4th of August for my
area, when we laoded there seven hours later, which it
would take that piece of junk to get there, I was told sort
of in a joking way that Mr. Quintero had called and said,
"Do you know what Max did? That man has stolen a goddam
aircraft." We were laughing, because the pilot said, "We
didn't steal anything. It was all authorized and
everything."
So the instruction that he gave to the people
down there was not to unload the aircraft but to refuel it
and just take personal things out and fly it right back to
Miami the following day.
Since all the equipment that was on board was
strictly spare parts for the aircraft that we had in that
aircraft.
That evening I had dinner with my friend at his
home. Mr. Quintero called. He said the airplane was ready
to return and he was told that it was unloaded on my
instruction, and he asked to talk to me.
When he talked to me he told me in Spanish, "Are
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you with me or are you against me?" So I explained the
best I. could. I said, "Look, this is not a situation of
being for or against anybody. The spare parts are needed
whole program is finished."
So he told me that is exactly what happened.
"The whole program has been terminated. I will be down
there in three days to close all the houses. You tell all
the pilots and the personnel there that they don't have the
blessing from anybody from up here, that if they do touch
or fly any of those aircraft it will be without our
authority, that there will be no payment for them, no
insurance for them, no gas or any more money at all, and
they will be on their own."
This is a call from Raphael Quintero, correct?
A Yes, sir.
I felt very strongly in support of these people
which are inside Nicaragua. I contacted^^m^^^^ who
I trust, one of the kickers in the program. I asked him if
he could find me a crew that will fly for free. I
explained to him the circumstances. He said he personally
would do it; he would check with others and let me know.
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He called roe later. He said, "I have found Mr.
Bob Sawyer" — who was later killed in the 123 — "who will
So I could count on this crew to be able to
continue to resupply these people. My purpose was to be
able to maintain the supply to them until the agency was in
a position to continue the aid to the Nicaragua freedom
fighters.
I contacted my local friend who was in charge of
the base. I explained to him the circumstances that we
were going through and asked him if he would provide the
fuel from his end to be able to maintain this operation.
This gentleman, who feels very strongly for the Nicaraguan
freedom fighters because he sees very clearly it is in the
best interest of his country, agreed to continue the supply
of fuel on his own.
At that point^^^^^^Btold me he
believed that if I did talk to the people most of them
would cooperate and fly on this mission. They were not
mercenaries. They needed money, but they respected and
supported the program.
So I called a meeting. I don't know whether it
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was the same night or the following night or later, but I
did hold a meeting and expressed what I had been told to
them so they were very clear that they no longer had the
blessing from their group, from their people, that the
operation, as far as I was told, was terminated, the house
was going to be closed, and that they would have no
salaries or no insurance policy for their families, and it
would be their responsibility if they flew any of those
planes.
I explained to them as best I could that I had
lost my native country to communism, and I knew what it
meant for these people to be down there without any
supplies for an extensive period of time until the agency
could take over the program.
I realized that they needed money for their
families to live on, but if any of them could afford a
month or two in this program it would be greatly
appreciated by a helluva lot of people.
Cooper was present, Hasenfus was present, and a
lot of the other pilots, and they all agreed that they
So I asked my friend to contact Mr. Quintero and
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kepaulus 1 explain to him that if he wanted to call that was fine, but
2 he would not be closing any base at this point in time,
3 that their group was willing to fly this mission for free
4 and I had been able to find the fuel to continue the
5 operation until the agency could take over.
6 At some point did you receive a telephone call
7 from Don Gregg?
8 A Yes, sir. I also had the understanding that
9 somebody else received a call down there and was told that
10 I had stolen the aircraft. And there was also a pending
11 suit by the owners of the aircraft. It was not quite clear
12 whether it was against me or the local people there.
13 So I received a phone call from Mr. Gregg in my
14 room. Mr. Gregg had been away during all of this time with
15 the vice president outside of the United States. I think
16 he was just approached upon his return. He told me on the
17 telephone, he said, "Felix, do you know anything about a
18 stolen aircraft and a suit?" I said, "Don, I have a
19 general idea."
20 He said, "Ollie has approached me. He said
21 there is a stolen aircraft down there. That could be very
22 embarrassing to the government." He didn't explain any
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details. He said, "You could be instrumental and help in
getting the aircraft released and it would be a great help
for the U.S. Government."
My understanding at the time was, and I still
believe, he had no idea what he was talking about. He was
just being used to use his influence auid friendship with me
to release this aircraft.
I discussed this with another friend locally
released. My idea at that point in time was that these
people probably learned that they were not going to get the
contract with the agency and they were just trying to move
out everything they had. It infuriated me quite a bit. I
explained to my friend, I said, "Look, there is no way I am
going to go to my friend here to release his aircraft for
these son of a bitches to steal another aircraft that might
be worth a half a million dollars.
So I did approach ray friend. I said, "Look, we
have been doing this without charging anything to these
people because we believe in this cause. They might have a
legal way to retrieve this aircraft." Because they had it
registered, I was told, in Panama. "But if that is the
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case, you have been providing space and support totally for
free because you believe in it, and if they want to take it
out legally, and they do have the means to do it, go ahead
and charge them for landing fees, guarding the aircraft,
There's a substantial amount of money that we can use to
buy a decent aircraft for the Nicaraguan freedom
fighters." To which he agreed, and he gave me permission
to go ahead and use his name in this proposal.
This is a discussion with your friend in the
host government?
A Yes, sir.
What did you do after you got the call from Don
Gregg?
A I also considered in my mind that the aid to the
Nicaraguan freedom fighters was already approved by
Congress and it would not be appropriate at this time for
me to approach Mr. Gregg and explain to him the situation
of these things. I was concerned that part of the program
could be taken to this group of people which I didn't
consider that well intentioned. So I decided to go to
Washington and explain to Don my concern about the
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kepaulus 1 possibility of these people getting part of the contract
2 with the agency, and also a situation that could be very
3 embarrassing for everybody, and I was pretty sure that he
4 didn't know anything about it.
5 So I called him over the telephone.
6 Q Let me stop you. You were concerned that these
7 people might get the agency contract and you didn't think
8 that they were the right people to have the contract; is
9 that what you just said?
10 A yes, sir.
11 You were also concerned that these people might
12 pull the aircraft out before the CIA could get back into
13 funding the operation and therefore the contras would be
14 without a logistics system to resupply them until the CIA
15 got back in; is that right?
16 A That's absolutely correct.
17 Q Tell me what you did.
18 A So I asked Don if I could meet with him at the
19 White House. This was, I believe, a Wednesday, So I could
20 fly on a Thursday all the way to Washington and meet him on
21 Friday. He agreed and said he would clear ma into the
22 White House at 9:30. So I flew into Washington.
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What day is this?
A I was to arrive and talk to him August 8, 1986.
What happened when you got there?
A I went to his office in the White House. He was
there. I don't know if Mr. Watson was there at the very
beginning. He later was. I started with telling Don that
I wished I never had to come to him under these
circumstances to explain this, but that I had learned of
this operation down there where Colonel North was involved
and he was using people that if known by the press, because
of their past background, with Wilson, etc., it could be
very embarrassing to the administration and everybody.
I also explained the condition of the aircraft
to him and explained my concern about possible corruption
in the program since I had been told, even though I didn't
have any concrete proof it, that hand grenades were being
bought at $3.00 apiece and sold to the contras for$9.00
apiece.
To that he was extremely upset. He picked up
the phone, even though I asked him not to, to bear with me
and not tell anybody. But he picked up the phone and
called upstairs to North's office. He was not there, but I
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kepaulus 1 understand that he did talk to Bob Earl. He started
2 telling him, "My friend Felix is here and what he is
3 telling me is outrageous. You should come down here and
4 hear what he has to say. He has mentioned the name of Tom
5 Kline, and goddamit, he's a dam snake. He doesn't have to
6 tell me anything about who he is."
7 He didn't want to come, but eventually Mr. Earl
8 came down. He tried to appease everybody, that it was best
9 to not really create a problem at this point in time.
11 been brought into this operation?
12 A No, sir, not at this time. I explained to him
13 the problem that was going on down there and that I had
14 become aware of it.
15 Q Do you recall telling him about the conversation
16 you had with Raphael Quintero where he said he was working
17 with. Mr, Green?
18 A I don't recall if I did or not. I might have.
19 It was a long conversation and it was a long time ago.
20 Did you tell him that Ollie North was associated
21 with this Wilson group and that that is what concerned you?
22 A Yes, sir. I am sure that he was also aware of
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th« individuals. Not that they were with hire, but he knew
the Individuals by name and their reputations.
Did you mention Secord's name In the meeting?
A Yes, sir.
Did Mr. Gregg appear to recognize who Secord
was?
A I just went on with all the names. The one that
he made the most out of was Kline when he was mentioned.
So you mentioned Kline and Secord. Did you .
mention Qulntero also?
A Yes, I did, sir.
He at least appeared to recognize Tore Kline
immediately as somebody that the government shouldn't be
dealing with) Is that right?
A Absolutely.
Do you remember whether you mentioned Mr. Gadd's
name In that meeting?
A Yes, I did. I thlnJt I mentioned Mr. Gadd In an
Incident that I heard from Mr. Qulntero, saying that two
guys were working, who I never met but only heard by name,
on the runway in^BllH °"* *'*' actually making a
$100 a day and the other was making$150 a day and Mr. Gadd
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was charging them $400 a day £or one and$450 a day for the
other. It was a substantial profit to him or whoever for a
considerable period of months.
So you told Mr. Gregg that Gadd was overcharging
for these employees that were working at the airstrip in
A Yes, sir.
Did you mention Mr. Dutton's name in that
meeting?
A I probably did, but I really can't be specific.
I cannot recall whether I did or not.
How long did you meet with Mr. Gregg before'
Mr. Earl was called on the phone?
A As soon as I started reporting the names to him
he almost immediately picked up the phone to call Mr. Earl,
but he didn't come down until a considerable time later.
Before he called Earl did you tell him what this
was with the private benefactor resupply operation?
A I really don't know exactly how I put it. My
main concern was that they would not get a contract.
you were concerned that they not get the CIA
contract to supply the contrasj is that right?
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V^kepaulus 1 A Basically, yes. If the press got a hold of it,
2 with the reputation that these people had, it would be a
3 disaster for the national security adviser to the president
4 to have people who had connection in the past and being
5 publicly exposed in problems with Qaddafi and Wilson, etc.
6 Did you tell Mr. Gregg that in that meeting on
7 August 8?
8 A I think I mentioned it. Yes, sir.
9 What did Don Gregg say to Earl on the telephone?
10 A Basically what I told you at the very
11 beginning. He said that he had heard this thing from "my
12 friend Felix, and he mentioned Mr. Kline's name," and he"
13 could not figure out how they could use people like that
14 and he wanted him to come down to listen to my story.
15 Did Mr. Earl come down to Mr. Gregg's office?
16 A He eventually came.
17 What happened then?
18 A I gave him part of my concern, and he just tried
19 to appease me. He didn't make much recommendation one way
20 or the other. Just to be calm, take it easy. He didn't
21 say much more th2m that, if I recall. All those things I
22 don't recall at this time.
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Was the problem resolved at that meeting?
A I later learned that Mr. Gregg called a meeting
to pass my concerns to other people. If I recall
correctly, after what I read, he called a representative
C
from the state Department, from the agency and the NS/ to
express ray concerns about the whole program so that they
would take appropriate action. I don't think he believed
that the Office of the Vice President would get involved in
something like this, but that he should pass it on to
people who could do something about it that would be
involved in this program. But he was not.
America?
A Yes, sir, I did.
What happened with the private benefactor
resupply effort after that meeting?
A After they reconsidered the situation they did
send a message down there that the owners of the aircraft,
the way they put it, were willing to continue the effort of
resupply until the agency would take over the program but
to be very clear that the aircraft did not belong to the
Nicaraguan freedom fighters, that they belonged to a
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private company, and as soon as the agency took it over
they were going to pull every single aircraft out with
them.
Did resupply flights continue after that point?
A Yes, sir, but it did continue with a Nicaraguan
guard on board to make sure the aircraft were not stolen.
That was the young guy that got killed on the October 123
crash.
He was on those flights to make sure that the
pilots didn't take the aircraft away; is that right?
A Absolutely.
A.
Where were you when the f^senfus plane went
down?
A I was in Miami.
How did you learn about the crash?
A My friend, ^H^^^H|^ft from the area
these flights were being staged called me over the
telephone and told me that the flight was overdue in
and how long they could have stayed in the air. I asked
him to make sure. It was a different area and a
possibility that they could land on an emergency basis, and
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'kepaulus 1 if he found out it wasn't that way, try to start a search
2 over the ocean area.
3 I f61t that this was the beginning of a big
4 problem. Since I was not on talking terms anymore with the
5 colonel, I felt that somebody in Washington should know of
6 this incident. So I called Sam Watson. I had not
7 discussed this with him before. I just told him that it
8 was my understanding that a Nicaraguan resupply plane was
9 lost and had either gone do%ni in the ocean or probably shot
10 down in Nicaragua.
11 I later learned through the press that he did
12 pass this information to the National Security Agency and
13 the White House situation room.
14 On the following morning we heard over the
15 Havana radio that the plane was shot dovm inside Nicaragua
16 and there was one prisoner. So I called him again to pass
17 this information to him.
19 country after the H^senfus incident?
20 A After that I didn't return until February 11,
21 1987.
22 The resupply operation completely ceased at that
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^ikepaulus 1 point; is that right?
2 A Yes, sir. After the H/^senfus crash the
3 operation completely ceased. I don't know what happened to
4 the owners of the aircraft who so badly wanted the
5 aircraft. The aircraft that was in Southern Air was asked
6 to be flown immediately into Central America, and if I
7 understand correctly, it was flown intomUmwith no
authority ^^^^^^^^^^^^^^^^^^^B. Apparently the
9 wanted to get rid of it as soon as possible, and it was
10 confiscated
11 Mr. Rodriguez, the last thing I want to ask you
13 group. Can you tell me what money you received from them?
A I was infl^Hm^with no pay from anybody.
15 Soon after the arrival of Mr. Quintero he came to us and
16 said that there was an operational fund fori
17 myself and himself of $1,000 per month to be used 18 operationally for us, for food and expenses or bringing 19 people to dinner, etc. So we took that during that time as 20 an operational expense. 21 So after I returned the offer was made to me to 22 be part of the resupply effort. I forgot to mention that WSiJ LPORTERS. Inc. 202-347-3700 Nationwide Coverage 80O-336-«46 806 7680 01 01 'kepaulus UNCLASSIFIED 51 during that meeting with Colonel North and Mr. Dutton in the White House after a while Colonel North told me he wanted me to sign a contract with Mr. Dutton to that effect. He asked me why I didn't want to be part of the organization. I told him I had done it so far and I didn't need to be paid for it. He- told me that I have to think of my family. Which didn't make me feel any better, because nobody had worried about my family before. He told me to 9 get together with Bob and write my own contract, but please 10 sign a contract with him. Which I did not. 11 When I went back to Central America my friend 12 ^^^^^fcame to me and said, "Look, Mr. Cooper has received 13 a specific instruction from Mr. Dutton not to pay you 14 anything because you are not part of the organization, but 15 Cooper insists that you were very, very helpful, and he 16 wants to pay you the$3,000 a month."
17 I told him, "Look, I cannot receive it. I don't
18 want the money. I don't need it here."
19 I^^^^^^^B told me, "Look, if you don't take it,
20 it will be another $3,000 these guys are going to be 21 making." 22 So at that point he convinced me on that basis. yNWSSIFIEfl Ace-Federal Reporters, Inc. 202-347-3700 Nationwide Coverage 800-336-6646 807 UNCLASSIFIED 52 7680 01 01 ^ikepaulus 1 So instead of getting my friends from Miami to support my 2 trips in here and back and forth to Miami, and my food 3 expenses, which I never received any amount of money or 4 other support fron the local ^^^^^^H I did receive the 5$3,000. I want to state that I did not sign the receipt.
6 H^H^^Hsigned the receipt for me. So legally if I
7 wanted to claim that I did not receive any money they could
8 not prove it, because the receipt is not signed by me. But
9 I did receive the money. I acknowledge it here
10 officially. There is no way I'm going to lie here or any
11 other statement.
12 So you received SI, 000 a month from
13 approximately January until June and then in June, July
14 A It wasn't effective until the following month,
15 after the meeting in the White House.
16 So it would be in July, August, September that
17 you received $3,000? 18 A Yes, and probably October. 19 Then after the H^senfus plane went down — 20 A After the H^senfus plane, I received, which I 21 did not sign a receipt for,$2,000 from Mr. Quintero for my
22 expenses to leave the house. Since the press was sort of
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hanging around my house all the time, I took the family to
the Keys for the weekend and stayed out of my house for
over three weeks. He suggested that I leave the country,
but I did not. I just stayed in the Florida area.
That is all the money that you received from
this operation, correct?
A Yes, sir. I handled the money on the fuel
account. I felt it was important to keep a record of it,
but it was in my hands never more than a few hours. I
guess one time 24 hours. When I received it I turned it
over to the local friends and received a receipt from them
and kept very clear records of dates, aircraft, gallons,
price per gallon. You have a copy of all of that.
You have given us a copy of all those receipts
and your records for the fuel expenditures; correct?
A Yes, sir, I have.
MR. BARBADORO: That's all I have. Thank you
very much, Mr. Rodriguez.
THE WITNESS: You're welcome, sir.
(Whereupon at 11:35 a.m. the deposition was
concluded.)
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yNOlASSIFIED
CERTIFICATE OF NOTARY PUBLIC & REPORTER
I, ."I'ichael G. Paulus, the officer before whom the
foregoing deposition was taken, do hereby certify that the
witness whose testimony appears in the foregoing deposition
was duly sworn by me; that the testimony of said witness was
taken in shorthand and thereafter reduced to typewriting by
rae or under my direction; that said deposition is a true
record of the testimony given by said witness; that I am
neither counsel for, related to, nor employed by any of the
parties to the action in which this deposition was taken;
and further, that I an not a relative or employee of any
attorney or counsel employed by the parties hereto, nor
financially or otherwise interested in the outcome of the
action.
Ily Commission Expires
February 29, 1992
:Jotary Public in and for the
District of Columbia
811
DEPOSITION OF DAVID ROSEMAN
Wednesday, June 10, 1987
U.S. House of Representatives,
Select Committee to Investigate Covert
Arms Transactions with Iran,
Washington, D. C.
The committee met, pursuant to notice, at 1:00 p.m.,
in Room B-352, Rayburn House Office Building, with Patrick
Carome, Staff Counsel, presiding.
On behalf of the House Select Committee: Patrick
Carome and Bruce Fein.
On behalf of the Senate Select Committee: Timothy
Woodcock.
On behalf of the Witness: Kathleen A. McGinn,
Assistant General Counsel, Office of General Counsel,
Central Intelligence Agency.
^iliCi Oeclassifie'i/Release-' nn JIJ>^87
under 3-oyis;jn' of E.U. 12r56
by IHA Nationa; Security Coufld ^ -^"^ T -r
812
T
1 MR. CAROME: If we could have the Notary please swear
2 in the witness, and if you could state your name for the
3 record on the record.
4 MR. MALLON: I am a Notary for the District of Columbia,
5 My name is Charles Mallon.
6 Whereupon,
7 DAVID ROSEMAN, ""^
8 having been duly sworn, was examined and testified as
9 follows:
10 EXAMINATION ON BEHALF OF THE HOUSE SELECT COMMITTEE
11 BY MR. CAROME:
13 A Yes. My name is David Roseman.
14 Q And what is your current oceu^tion?
15 A I am an attorney with the Central Intelligence
1g Agency and I serve as Chief of the Intelligence Law Division
17 at the Agency
^Q Q And how long have you been Chief of the
ig Intelligence Law Division?
20 A For a little more than one year.
2^1 Q You started in that position when?
22 A Approximately April of '86.
23 Q Why don't you just briefly tell me your
54 educational background, starting with college^ and the
25 positions which you've held since graduating?
niSSIElEIl
813
UHSa^Blft^T
A Certainly. I graduated from George Washington
University in 1970, and graduated from Georgetown University
Law School in 1973. I took the bar in 1973 in the State of
Maine and became a member of the bar, in Maine, in 1973,
and I began my legal career as an Assistant Attorney General
for the State of Maine.
I was in that position until 1980 when I got my
position with the Office of General Counsel at CIA. I
started at CIA as a position as a generalist, meaning that
I received assignments from a number of different divisions,
and within a year I was assigned to the Intelligence Law
Division and was subsequently named Deputy Chief of the
Intelligence Law Division.
Q And what time did you first become a lawyer in
the Intelligence Law Division?
A That would probably have been in 19 -- well, it
was within a year of my entering on duty with the Agency,
which was, I entered on duty in July of 1980, so it would
have been some time I think in 1981 that I began to work with
the Intelligence Law Division.
Q And your first position in that division was
what? '*' ^^ -1% '^
A I, at that time there was a Chief of the division
and I was — I simply served as his assistant, and to the
extent that there was additional work, which there always
IINClASSIFIEfi
814
25
isaissiffiBr
1 was, above and beyond what we could handle, it was assigned
2 out to other attorneys who were considered to be generalists.
3 Q Okay. And in or around the time of November
1985 what position were you holding?
A November 1985, I would have been the Deputy
Chief for the Law Division.
Q And is that the same for the period in or around
January 1986?
A Yes, that's correct.
10 Q And what were your general duties in that
11 position';
12 A My duties as Deputy Chief — well, let me
13 describe first what the — the overall responsibilities of
14 the division.
15 The division has primary responsibility for
15 handling questions relating to Executive Order 12333, which
■(7 deals in large part with collection ut j^ian^^ion and
retention and dissemination of information on U.S. persons,
19 and it also contains guidelines on the limited Agency
20 activities within the United States. These are guidelines
21 under Attorney General approved procedures. That's the
22 primary role of the division.
23 The division also handles questions involving
24 the Intelligence Oversight Board,
As Deputy Chief of the division, of course, I
UMCLASSIHEIU
815
mmm
received my assignments principally from the Division Chief,
whose name is Bernie Makowka; and in Bernie's absence, I
would serve as Acting Chief.
Q Okay.
MR. CAROME: It occurs to me that there is a
brief introduction I should have probably given at the start
of the deposition which I might as well do now.
Just for the record, my name is Patrick Carome .
I'm Staff Counsel for the House Select Committee to
Investigate Covert Arms Transactions with Iran. It is
possible that a staff counsel to the parallel Senate
committee is going to be joining us in this deposition
midway through.
Both of the committees were established pursuant
to resolutions and have various enacting roles. The Central
Intelligence Agency has previously been provided with copies
of our resolution and rules; and, just for the record, I
have earlier, before we started today, have provided you
with copies of both of those things.
The mandate of the House committee is to
investigate the circumstances surrounding the Iran affair
and also the U.S. involvement with the contras , and this
deposition is being conducted purmaaa* tc^fciujse rules.
BY MR. CAROME:
Q Turning now more to the substantive matters that
•l^^^QilL.
816
1 I want to cover, when was the first time — strike that.
2 The Intelligence Law Division is not normally
3 involved in the preparation of covert action findings; is
4 that right?
5 A That's correct.
MR. CAROME: The record should reflect that we
7 have just been joined by Bruce Fein, who is an attorney with
8 the House Select Committee.
g BY MR. CAROME:
•JO Q Is it correct, Mr. Rosemem, that the Intelligence
•J1 Law Division is not normally involved in the preparation of
12 covert action findings?
13 A That is correct.
Q In 1985, did there come a time where you working
on a covert action finding?
A Personally I was not involved in 1985 in working
on — let me step back, because the times — we got involved
on the Iran finding on 2 and 3 January 1986 and were involved
with another , ^^^^^H^^^^^^BH^finding, which may have
been in late 1985, so let me correct that.
Q You were involved in preparation of a covert
22 -action |ipHnt;^ 1985; is that right?
yj A It probably would have begun in late 1985, in
„. late December of 1985.
24 ^
When you say you, you mean my role personally?
Muma
817
m^^
1 Q That's right. I'm speaking of your role
2 personally.
3 A Yes.
4 Q And what did that finding that you were involved
5 in, in 1985, deal with:
6 A To the best of my recollection, we were involved
7 in a finding dealing with^^^^^^^^^^^B And have not
8 reviewed that finding, so that's the best recollection I have
9 at this time.
10 Q Did that finding deal with any partedcul ay-^
countries?
12 A I do not believe so.
Q And when you say "we were involved," who besides
14 yourself was involved in t ha tE^^^^^^^^^^^^H finding?
15 A It would have been, I am certain, Bernie Makowka,
1g the Chief of the division. It was myself and Gary Cole, who
^j was one of the attorneys working for us, assigned -- one of
1g the attorneys assigned to Intelligence Law Division,
Q Is Mr. Cole an attorney who reported directly to
you at that time?
A Yes, that's correct. To me and, or actually
22 directly to Bernie as Division Chief, but to me if you want
to say through the chain of command.
Q And is it correct that thii
finding was the first finding that you were ever involved in?
IIEUSSIEIEIL
818
lINEft^RIt^
1 A Well, to say the first finding that I was ever
2 involved in, I have been involved over the years in questions
3 related to findings, covert —
4 Q Let me see if I can be more specific with the
5 question.
6 Was that the first instance in which you were
7 ever involved in the drafting of the actual finding itself?
8 A I believe so; yes.
9 Q Was that also the first instance that you're
10 aware of in which the Intelligence Law Division was involved
•jl in the actual drafting of a covert action finding?
12 A Well based on my knowledge, what I know at this
13 point in time, the answer is no. Because I understand that
14 Mr. Makowka was involved in drafting what has been referred
15 to as the mini-finding of, I believe, November 1985. As to
1g whether or not Mr. Makowka has been involved in other findings
17 prior to that time, I do not know
^g When I say involved in, I should say the saime
^g thing, actually drafting. Because he, as well as I, have
2Q been involved over the years in a number of questions related
to covert action programs or special activities.
Other than one^^^^^^^^^^^Vfinding
findings that did pertain to Iran that are really the subject
of our investigation —
A Um hum
MAMP
819
mwm
ET
1 Q — are you aware of any other covert action
2 findings prepared by the Intelligence Law Division?
A No, I am not.
4 Q I take it that there did come a time where you
5 became involved in the preparation of a covert action finding
6 relating to Iran?
7 A That is correct.
8 Q And when did your involvement begin on that?
9 A My involvement began on that I would say on
10 2 January 1986.
11 Q And how did it begin?
12 A Well, I recall that our Division Chief was on
13 leave, or going on leave in the end of 1985 and —
14 Q Who was the Division Chief?
15 A Mr. Makowka.
1g Q And he asked Gary Cole and myself to finish the
17 drafting and the work on th^^^^^^^Hjj^^H finding by,
•J8 believe he probably said by the end of — by 31 December or
19 30 December, whatever the last working day of the year was;
20 and he indicated that that was something that needed to or
21 should be sent up to the General Counsel as quickly as
22 possible.
23 Mr. Cole and I did the work on that finding, and
24 in preparing the finding itself, in part because we had not
25 previously drafted "lindings ourselves and in part because
lUUSSiElL:
820
ll^MF
10
1 our practice is to do the most thorough legal job we can, we
2 contacted — I believe we would have contacted George
3 Jameson or — it was either George Jameson or Ernie
4 Mayerfeld, who may have been counsel — whoever was counsel
5 for the DO at that time who ordinarily dealt with these
6 kinds of matters, or it might have been George Clarke, who
7 George Jameson or Ernie Mayerfeld, I believe, reported to.
8 We contacted them to get background paperwork
9 on preparation of findings and the proper format and who it
10 goes through within the Agency and who it goes through
11 outside of the Agency, so that we could do the best possible
12 job on that.
13 Q Is your work on this matter all happening toward
14 the end of December? Is that correct?
15 A Yes. I'm referring now to the
16 'finding, which is a lead-in to your question as to how we got
17 involved or how I got involved in the Iran "finding.
18 Q And the activity you've just described took place
19 the last 10 days or so of December?
20 A I will say within the last 5 or 10 days in
21 December.
22 Q Do you know whether or not the activities you
23 were just describing on the^^^^^^^^^^^^^Hfinding were
24 related to a meeting that Mr. Makowka attended at Colonel
«c North's office on
>n Christmas Eve, 1985?
820
821
1 A I'm sorry . Could you repeat that?
2 Q Are the activities on the counterterrorism
3 finding that you have just described related to a meeting of
4 Mr. Makowka and Mr. North on December 24, 1985?
5 A To my knowledge, they were not related.
g Q Were you aware of that meeting?
7 A I might have been aware generally of the meeting,
but not of the substance or the specifics of tne meeting.
Q In other words, Mr. Makowka may have come back from that
meeting and said to me, I just met with Ollie North, or, I
just had a meeting at the White House; or he may have said,
Dave, I'm going down this afternoon to the White House to a
meeting with Lieutenant Colonel North, something of that
nature.
However, on certain matters as the then Division
Chief, the General Counsel would deal with Bernie Makowka
directly and not with me. Because we operated on a need-to-
know principle in certain sensitive matters, the General
Counsel would deal with the then Division Chief and it would
be — that information wouldn't be shared with me.
Getting back to our preparation on the
finding leading into our involvement in the
Iran finding, we finished that work, the work on the
■finding, on a timely basis. We presented
that Finding to the General Counsel, and I recall that the
iimjissiBfi
822
jiwtissffiiT
12
1 General Counsel was very, very pleased with the work we had
2 done, both substantively and the timeliness of our response.
3 And that probably would have been, we turned that in I will
4 say either the last day in December or the first working day
5 in January of 1986.
Q That would have been January 2nd, I believe.
7 A Probably January 2nd. But I recall that we
8 would have — I will — my best recollection would be that
we turned that in the last part of December 1985.
10 Q Could I just ask, did the
11 fcnding bear any relationship to discussions that were going
12 on in the Office of General Counsel about an enterprise
13 theory for prosecution of terrorists?
14 A I am aware of the enterprise theory that was
15 discussed at that time in the office. I can't recall that
1g specifically but I don't believe so. I don't believe it
^j dealt with that. But I really cannot recall, though, with
^g any specificity.
Q We have just now gotten up to the January 2nd
time frame —
A That's correct.
Q — and I think you're going to —
A That's right.
Q — begin to tell us what it was that brought you
25 into the drafting of the Iran finding.
llimSSIEI£lL
rn
823
'^(iSSii)i&'
1 A That's correct.
2 On the 2nd of January, and this would have been
after we completed our work, at least our draft work on the
4 ^^^^^^^^^^^^H finding, the General Counsel called me into
5 this office and said, in effect, that he was very pleased
6 with the work that we had done and that he had another matter
7 that was of extreme sensitivity and that he wanted me to
work on it.
g And he then described this next matter and it
10 was this, it was the finding related to — it was the
11 so-called Iran finding.
12 Q So this was described to you in a meeting in
13 Mr. Sporkin's office; is that right;
14 A That's correct,
,J5 Q And you are fairly certain this was on
1g January 2nd; is that right?
A I'm fairly certain only because I have reviewed
the two Iran findings, amd one is dated 2 January and one
is dated 3 January. And my recollection is that Mr. Sporkin
said that this was another finding that needed to be
prepared, and needed to be prepared expeditiously.
And I recall that we, Mr. Cole and I, prepared
17
18
19
20
21
22
23 that finding by close of business that day
Q All right. If we could turn to what it was that
Mr. Sporkin said to you in this first meeting on the subject
824
1 of the Iran finding.
2 A Yes.
3 Q What did he tell you needed to be done?
A The best that I can recall on that is that, as
I said, he called me into his office and said that there was
a matter of extreme sensitivity and he wanted me to work on
that. And he described the matter as —
MR. CAROME: Could we go off the record for just
a second?
10 (DiscussionF of f the record.)
11 MR. CAROME: Back on the record.
12 The record should probably reflect that Tim
13 Woodcock, from the Senate staff, has just joined us.
14 MR. WOODCOCK: 25 minutes late.
15 BY MR, CAROME:
16 Q Mr. Roseman, you were just describing what it
17 was that Mr. Sporkin said needed to be done, and X believe
18 you were just about at the point to describe what type of
19 project the finding was to relate to.
20 A Yes. My recollection on this, I should add, is
21 in large part based on my reviewing the finding itself
22 because, obviously, whatever was contained in there or most
of what was contained in there was based on what Mr. Sporkin
MR. CAROME: Why don't I have a copy of the
imCliSSlQEL
825
lilSWfi
ET
15
finding, the draft finding, marked as an exhibit, and I will
put it in front of you so you can look at it.
THE WITNESS: Thank you.
(A document was marked Deposition
Exhibit DR No. 1 for identification
BY MR. CAROME:
Q Mr. Roseman, I show you what has been marked as
Exhibit 1. It has a CIIN number 1119, and it's a document
dated January 2, 1986, and it appears to be a draft finding
on Iran.
A Mr. Sporkin basically said that we were, or words
to the effect that we were, the U.S. Government was trying
to establish an initiative or open a line of communication
with the moderate elements in Iran and that we, in order
to, you know, in furtherance of that -- in furtherance of
that goal a Finding needed to be prepared to support the
sensitive special activity or covert action.
Q What was said about the types of activities that
would be taken? What did Mr. Sporkin say at that meeting
on those subjects?
A Other than to tell you generally what I've just
described, I really can't — I can't recall specifically
any specifics of what he said at that point in time.
Q Let me see if I can ask you a few specific
questions on things that might have come up to find out
HMCliS£IEtEa
826
yfWSfflSBET
1 if you have a recollection whether they came up.
2 A Yes. There is one thing that I did just
3 remember, but why don't you go ahead.
4 Q What is the one thing that you remember?
5 A I remembered in part because — it's Mr.
Woodcock.
Q That's Mr. Woodcock.
A Yes. I have previously been interviewed by
g Mr. Woodcock and at the close of -- towards the close of that
10 interview, Mr. Woodcock asked me whether there was any
11 discussion during my meeting with Mr. Sporkin about the
12 Israelis being involved in this, whether Mr. Sporkin
13 mentioned that to me. And I had not previously mentioned
14 that in my interview with Mr. Woodcock, and I said at the
15 time that that sort of jogged my memory a bit and that I
recall that that was mentioned. I am not certain about that,
but I recall that that — that Mr. Sporkin may have said
something along the lines of, you know, this is -- in part,
the sensitivity of this is due to our working with our
allies on this including, or our ally Israel or our allies
including Israel.
Q Do you recall what he said on what specifically
Israel had to do with the activity?
A No, I do not. And it may have just been in
terms of sensitive project. That may have just been the
iMi&^lElEL
827
^^WSk'
_^_ 17
nature of it.
Q Did Mr. Sporkin say that arms or any other types
of material would be delivered to Iran?
A I presumed that he did because that is all
contained -- the finding states that — the finding, or part
two of the finding, if you will, the second paragraph of
the finding, states that we would, the U.S. Government would
provide arms, equipment and related materiel to the
Government of Iran. And I recall that when we, that when
Mr. Cole and I submitted this draft finding to Mr. Sporkin,
which I believe would have been on 2 January, that Mr..
Sporkin made, at least initially there were only minor
So I would -- I could only assume that in our
initial discussion he mentioned that this finding included
arms and equipment and related equipment.
Q Did Mr. Sporkin say anything in this initial
discussion about hostages and that one objective of the
activity contemplated was release of hostages?
A I really do not recall that.
Q You have no recollection of the subject of
hostages being mentioned?
A No, I do not. But we, you know, again the
finding talks in terms of our activities done in part to help
protect against terrorist activities directed against U.S.
\\m h^^mn
imctiiissiEiiifeT
18
1 persons. It's possible that he may have mentioned that. I
2 do not recall it.
3 But clearly, one of the purposes of the finding
4 was to help protect against terrorist acts directed against
5 U.S. persons, U.S. property, U.S. interests.
Q Did Mr. Sporkin say anything about an earlier
finding relating to Iran?
A I don't believe that he did. If you're referring
9 to the finding that Mr. Makowka — I later learned that
10 Mr- Makowka worked on in, I believe, November of '85, I
11 do not believe that Mr. Sporkin mentioned that earlier
12 finding to me at that time or any previous time or subsequent
13 time,
14 Q When did you first hear anything about the
15 November 1985 finding;
^g A I can't give you a specific date but I assume it
iy probably would have been in November or December of 1986
,|Q when the news became public about the whole Iran initiative.
19 But I do not believe that M(^. Makowka ever discussed that
20 finding with me.
2< And again, let me clarify. Mr. Makowka may have
22 said to me something along the lines of I'm working on a
very sensitive project for Stan or I had to stay late last
night working with the General Counsel, but that would have
been it.
IMASnL
lllTOSfflFirET
19
If he had been instructed by Mr. Sporkin not to
discuss the specifics with me, he would not have, nor would
I have asked. And that is our practice, certainly in our
division.
Q And I take it that in late 1985 and early '86
you heard nothing about a 1985 finding being signed relating
to Iran; is that right?
A I believe that's correct.
Q Did Mr. Sporkin mention Oliver North's name in
the initial discussion with you?
A He might have mentioned it to me . I will say
that Mr. Cole and our secretary and myself certainly knew
that he was bringing the 2 January or the 3 January finding,
the 3 January redraft of the White House, and certainly
my understanding was, my belief was that that was going to
Oliver North.
Q Did you know who North was at that time?
A Generally I knew who he was. I never had any
dealings with him myself. I knew that he was a senior
official in the National Security Council and seemed to be a
person who wielded a fair amount of power in the National
Security Council, but that was the extent of my knowledge of
Mr. North.
Q In what sense was it evident to you that Mr.
North wielded a fair amount of power?
iiNr.us<;ifiEJi
830
wmm
20
1 A In the sense that his name had been mentioned on
2 a number of occasions at office, division chief meetings.
3 Q Who would mention his name?
4 A Oh, possibly George Clarke, who, as I said
5 earlier, had responsibility in covert action areas. Possibly
6 the General Counsel.
7 Q What do you know about the relationship between
8 Mr. North and Mr. Sporkin at or around that time?
9 A I know nothing of the relationship between those
10 two gentlemen.
11 Q You knew that they would have meetings and phone
12 calls, didn't you?
13 A Well, certainly I knew that they had — again, as
14 I said — as I said earlier, not to repeat all of that, my
15 understanding was that Mr. Sporkin was going down to see
16 Mr. North to bring this finding. Either Mr. Sporkin had
17 said that to me directly, that he had to get down to the
18 National Security Council or to the White House, or I
19 surmised that.
20 Q Were you aware of any interaction between North
21 and Sporkin prior to January 2nd?
22 A Nothing specific, other than what I just said to
23 you. His, Mr. North's name I recall had been mentioned at
24 division chief meetings.
25 Q Did you ever see North at the CIA?
UNHAmitL
831
A No, I did not.
Q Have you ever met North?
A No, I have not.
Q Have you ever spoken to him on the phone?
A No, I have not.
Q Did Richard Secord's name come up in this
initial conversation with Mr. Sporkin?
A No, it did not.
Q Did Secord's name come up in any discussions you
had on this subject in January of '86?
A No, it did not.
Q Have you ever met Secord?
A No.
Q Have you ever spoken to him on the phone?
A No.
Q Was anyone else present during this initial
meeting with Mr. Sporkin and yourself?
A I'm not certain about that. The Deputy General
Counsel may have been present at that meeting.
Q And who would that have been? Who was that?
A That would have been Mr. Dietel.
Q What is your best recollection on whether or not
Mr. Dietel was present?
A As I said, I'm not certain. If he were present,
he was almost entirely or entj.rely__in__ijjst a — just present.
m\
yiw.ww^
22
•J The instructions I was receiving and the discussion was really
2 with Mr. Soorkin
3 Q Anyone else present for this meeting?
4 A No. Mr. Cole was not present at that meeting,
5 and Mr. Cole assisted me in drafting this finding, the
3 January finding.
Q I want to get to that, but I want to see if there
is anything else we can learn about the first, January 2nd
Q meeting.
About what time of day was that meeting held,
do you recall?
A I think it was held either late in the morning
or around the lunch hour, or perhaps early afternoon, in
that time frame. I knew -- 1 think we had several hours,
you know. Mr. Sporkin, again, told us that he needed
something back expeditiously, and he either said this or the
implication was he needed it by close of business that day.
And I know we had several hours to do it.
Q Did the subject of whether or not there would be
during this initial discussion with Mr. Sporkin?
A In reviewing the 2 January and the 3 January
to the committees. The 3 January finding has alternative
language. That subject came up. Whether it came up
ML&SSIflEIL
833
UIKi^ffi^T
23
on the first, or in my initial meeting with Mr. Sporkin or
the meeting the next day, I don't remember.
I think it might have, it might have come up in
the initial meeting and it might have come up along the lines
of this is just a sensitive matter, but I'm not certain on
that point.
Q I take it that it was clear during this
discussion, this initial discussion that the objective of
what Mr. Sporkin was asking you to do was to get a finding
prepared; is that right?
A ' That's correct.
Q Did you discuss whether or not there should be
a finding or was it clear right from the start that there
needed to be a finding?
A No, we did not discuss whether from — we did
not discuss whether there should be a finding. We did not
discuss any policy implications on the finding. It wa s a
matter of the General Counsel saying to — it was a matter
of the General Counsel giving me instructions to prepare
this, and then my reviewing section 501 of the National
Security Act and preparing the finding in accordance with
the statute and in accordance with the previous documents
that I have mentioned to you that we had located.
Q Did Mr. Sporkin in the initial discussion say
anything about the National Security Council and its role in
\e National security ijouncu
Mime.
834
im^HP'
24
1 its role in the contemplated activities?
2 A I do not believe so. I'm fairly confident he did
3 not.
4 Q Did you understand that the activities under
5 consideration were to be carried out by Central Intelligence
6 Agency people?
7 A That wasn't discussed but that would have been
8 my understanding. The executive order. Executive Order
9 12333 states that the agency within the United States that
10 will ordinary carry out what Executive Order 12333 defines
11 as special activities, or what's more commonly known as
12 covert action, is to be carried out by the Central
13 Intelligence Agency unless the President specifically finds
14 that another agency is more fully — is better suited to
15 conduct that kind of an activity.
Ig So my understanding would have been that this
nee Agency carrying this
17
18 out.
Q Did Mr. Sporkin give any indication to you at
that first meeting or any other time —
A Um hum.
Q — that there had been an earlier shipments of
arms to Iran that the CIA had been involved with?
A No, he did not.
MR. FEIN: Did he indicate whether private
mamL
835
OlTOKSStBIST
25
parties would be involved in the covert action contemplated?
Since that was a part of the drafting evolution —
THE WITNESS: When you say private parties
involved in — did you say private parties —
MR. FEIN: Yes, I did.
THE WITNESS: — involved in providing arms?
MR. FEIN: Well, in the overall covert action
that was the subject of the finding.
THE WITNESS: Well, with regard to providing arms,
I don't recall that there was any discussion of that. There
presumably was discussion of private parties in the sense
that the 2 and 3 January findings refer to working with
individuals; for example, working with individuals and
organizations both within and outside of Iran and liaison
services and other foreign government entities. So in that
general sense, that was probcibly mentioned that there would
be, you know, the finding should be written to include not
only working with another government but with a liaison
service or individuals or organizations.
But, as I said, there was no discussion on
using private persons, to the best of my recollection, to
provide arms to the Iranians.
BY MR. CAROME:
Q Did Sporkin, in this initial discussion, say
anything about who within Iran was to be the recipient of
UMPi i^^Ol
836
IRfti^ftSr
^ _^ 26
1 arms?
2 A I don't recall. I can only say that in reviewing
3 the 2 January finding and comparing it with the 3 January
4 finding, the 2 January finding refers to providing arms to
5 the government of Iran, whereas the 3 January finding refers
to providing arms to moderate elements within the government
7 of Iran, or moderate elements within Iran. I don't have the
3 3 January finding in front of me.
Could you repeat that one, please? Repeat the
IQ question?
^1 Q- The question was, was there any discussion at
this initial meeting with Sporkin on the subject of who
within Iran was to be the recipient of arms?
A Okay. I can't recall whether at the initial
meeting that discussion came up, but certainly during one
of the meetings that subject was discussed, or that subject
was, Mr. Sporkin said you — yes, that subject was discussed.
Q And what did he say on that subject?
A He — I can't remember specifically, but it was
along the lines of the finding should be drafted or needs to
be drafted so that we, so that we provide arms to the
moderate elements in Iran, or in the Iranian government.
And I do not recall that there was much discussion on that.
It was a we tt er of Mr. Sporkin as the General Counsel giving
me instructions as to how to draft, how to prepare this
IMASSIQEL
837
mmm
finding.
Q Mr. Sporkin said that this was a highly
sensitive matter, is that right?
A That's correct.
Q Did he explain to you why it was sensitive?
A I don't recall. But I do recall at the time
that he, the whole subject was — I do recall that at the
time that I was called in by Mr. Sporkin and he mentioned
the subject matter it seemed to me to be a very, an
extremely sensitive kind of subject in the sense that we
were establishing an initiative with the Iranian government.
Q And why would that be sensitive?
A Because at the time we did not^relations with
Iran. That was my perspective.
Q Was one of the factors that made it sensitive
at that time the fact that any public disclosure that the
United States was initiating relations with Iran would be
a political fire storm if disclosed to the public?
A Could you repeat that again, please?
Q Was one factor contributing to the sense of
sensitivity of this matter the fact that public disclosure
of the subject would cause a political fire storm?
A I do not know what Mr. Sporkin was thinking but
that was not a consideration of mine. It just seemed to be
to me that this was a — that, you know, Iran was a terrorist
ICUOTEi.
W85IFW
28
1 or is a terrorist — was and is a terrorist nation or nation
2 that supports international terrorism, and that we did not
3 have relations with Iran, and that this was an initiative
4 to establish relations, and in that sense, in a foreign
5 policy sense, if you will, it seemed to me to be very
6 significant and something that was very sensitive.
7 MR. FEIN: Well, isn't it true that those who
8 are related to the Shah in the United States in the
9 aftermath of the Khomeini takeover were summarily executed
10 in that, if they were moderates who it was publicized, in
11 Iran, were making contacts with the United States and that
12 fact was leaked, they could be summarily executed? So the
13 whole effort to establish a link with the moderates would
14 collapse because any publicity would be the demise of the
15 moderates in Iran, since there is no indication that the
16 Ayatollah himself has changed colors like a chameleon.
17 THE WITNESS: I don't know the answer to that
18 question.
19 BY MR, CAROME:
20 Q Did Mr. Sporkin say anything about the fact that
21 the weapons to be provided to Iran were to be used in the
22 Iran-Iraq conflict?
23 A Again my recollection is based on what's contained
24 in the finding, and I would presume that he did state that.
25 Q You have no independent recollection of the
16
17
18
19
20
21
22
23
24
25
m^^
29
1 discussion of use of the weapons in the Iran-Iraq war?
2 A Well, I do — I have, I have a, some recollection
3 that in these, that in this discussion or in these
4 discussions with Mr. Spor)tin that we — there was concern
5 that the weapons not be used against U.S. interests, and
6 that's reflected in the finding.
7 Q Was it also evident that the weapons would be
used against Iraq?
g A As I said, from reading the finding, I would
have to assume that that was something that was discussed.
Q How long did the first meeting with Mr. Sporkin
10
11
12 last?
A It may have lasted, more or less, 10 to 15
minutes.
^g Q And what happened after the meeting?
A Well, before the meeting closed, having worked
on a previous|^^^^^^||inding with Mr. Cole,
have initiated this or Mr. Sporkin may have initiated this,
but I certainly didn't, I certainly on something like this
would not have had Mr. Cole assist me on this without getting
specific authorization from the General Counsel.
So I may have said Mr. — I may have said,
Stan, do you want me to work on this alone or do you have
any objection if Gary Cole works on this with me; or Stan
may have said, you can do this alone or with Gary Cole. It's
840
IWSBISSieiilT
30
1 not to be discussed with anyone. It's not to be discussed
2 with anyone else.
3 But it was clear, my orders were clear that I
4 could work with Gary Cole but that this was not to be
5 discussed with anyone else within or outside of the office.
And your question was, what was the process after
that? I immediately called Gary Cole and described this,
described as Mr. Sporkin had described it to me, and the two
9 of us sat down and drafted this. We may have actually sat
10 down together and drafted it or we may have worked
11 independently or divided it up, you know, one person working
12 on one paragraph, one person working on the other.
13 Q Did Mr. Sporkin indicate to you that you should
14 complete a draft of the finding before the end of the day?
^5 A I think that he did. That certainly was my
16 understanding, and I recall that this finding was submitted
17 to Mr. Sporkin by the close of business. If it were not by
■jg close of business, it would have been -- well, it's dated
19 2 January. I'm assuming that it was done by the end of that
20 ^^y •
Q Did Mr. Sporkin say anything in the first meeting
about how soon the contemplated activity was to occur?
A No, he did not.
Q So that afternoon, I take it you and Mr. Cole
25 sat down and began working on the drafting of what became
841
mms
31
Exhibit No. 1; is that right?
A That's correct.
Q And what sources did you draw on to prepare this
first draft finding?
A I would say we drew on three sources. We drew
on the information, the directions that Mr. Sporkin had given
to me, number one. Number two, we drew on the previous
materials I mentioned at the outset of this deposition --
other findings and related papers, and the proper formatting
of those types of findings. And, number three, we drew on
the language of section 501 of the National Security Act of
1947 to ensure that the finding was consistent with that —
consistent with that language and fell within the parameters
of that statute.
Q And by the end of the you —
A And I should add we also certainly referred to
the Hughes-Ryan amendment, the so-called Hughes-Ryan
amendment .
Q And you completed the draft by the end of the
day, is that right?
A I believe that we did.
Q In looking at the draft I see that there is a
sentence at about the middle of the page that refers to
provide intelligence, counterintelligence, et cetera, to the
iiAinn^siflfo,.
842
m^!^
32
1 A Um hum.
2 Q What do you recall Mr. Sporkin saying on the
3 question of providing intelligence to alternative leaders?
A Well, he might have said, and he probably would
have if there is that language in this first draft -- he
probably said that the U.S. Government was attempting to
establish relations with more moderate elements within Iran
or within the Iranian government. But I don't believe that
9 he said anything substantially beyond that.
10 Q He must have said something along the lines of
11 we're going to provide these elements with intelligence,
12 is that right?
13 A He might have or this — no, this draft is dated
2 January 86. It's possible that Mr. Cole and I presented
him with the draft and Mr. Sporkin revised it, and then this
was printed out on our typewriters as the 2 January 86
finding at the end of the day.
So it's possible that the language that Mr. Cole
and I gave to Mr. Sporkin is not exactly what you see here.
Q I see.
A In other words, we may have gone back towards
the end of the afternoon and said, Stan, here is a draft,
and he looked at it and made some changes in it and then gave
it back to us for retyping.
Q Do you recall that's the way it happened? That
UJUCUmLl
843
W^^>1^
33
you presented Mr. Sporkin with a draft on the 2nd?
A You've asked me that before and I ~ to the best
of my recollection, I think we did.
Q So you recall having taken a draft back to Mr.
Sporkin later that day, is that right?
A Yes, I do.
Q Do you recall doing that personally, actually
walking it up to his office?
A Yes, I would have done that.
Q And did you have any conversation with Mr.
Sporkin at that time?
A I, I'm not certain but I don't believe so. I
believe that I probably showed him the draft and waited in
the office, either in his office and/or in my office,
waiting for him to give me any further instructions; and I
would not have left that evening I'm certain until the
General Counsel said that's fine for tonight.
But I don't recall whether we had any further
discussion at that period of time or whether it was a matter
of handing the General Counsel the draft and having him
review it and make whatever changes he might want to make
in that.
Q This draft that's marked Exhibit 1, do you recall
or can you tell whether that is what you and Mr. Cole
originally drafted;
WUISSIQLL
844
uimsswi^'
34
1 A It certainly is — I can't, as I said before, I
2 can't say with certainty that this is exactly the draft that
3 we gave to Mr. Sporkin and that there are no changes. But
4 this certainly had most of the elements of what we did;
5 in other words, we didn't give him a piece of paper and
6 Mr. Sporkin totally revised it — Mr. Sporkin totally
7 rejected our work and revised it and came up with this.
8 Q And you can't recall anything that Mr. Sporkin
9 would have told you at the time you presented him with this
10 first draft on the 2nd; is that right?
11 A No, I really can't. I would be speculating if
12 I tried to do that.
13 Q You don't recall him saying, you need to make
14 these changes in it, at that time, do you?
15 A Well, I'm not sure. You know, there are obvious
16 changes between the 2 January and the 3 January draft and
17 I am not certain whether he said that evening on 2 January,
18 I want some additional changes, or whether he called me back
19 into his office again on 3 January and asked us to work on
20 that again.
21 In fact, my best recollection of this was that
22 I provided the draft to Mr. Sporkin and that he made some
23 changes and — when I say my best recollection, my initial
24 recollection of the scenario was that I provided this to
25 Mr. Sporkin and he made some changes, and then he went down
IMiHSSlEe^
845
m&iMi^
to the National Security Council that first evening; however,
the records don't reflect that, so I assume that I'm
incorrect on that.
Q What you assume is incorrect is that Sporkin
didn't go down to the White House until January 3rd; is that
right?
A That's right. The records reflect that he did
not go down on the 2nd and that he brought the 3 January
finding down on the 3rd, and I have no reason to doubt the
record on that.
Q Is it possible that you didn't present the first
draft to Mr. Sporkin until the following morning; namely,
January 3rd?
A That's possible but I believe it's highly
unlikely. When the General Counsel indicated that he wanted
something of this nature done, done quickly, I can't imagine
that Mr. Cole and I would have left the office until that
would have been done. And I'm sure our secretary -- I know
our secretary would have stayed regardless of how late that
was.
Q And Mr. Sporkin would have stayed that late, too?
A Well, that would depend. If we finished at
nine o'clock at night, he might not have stayed. But again,
I don't — I believe that we, as I said before, I believe we
provided this to him the first evening.
'mASSlElElL
846
BNBII^IW'
1 (A document was marked
2 Deposition Exhibit DR No. 2 for
3 identification.)
4 MS. McGINN: Can we go off the record for a
5 minute?
6 MR, CAROME: Sure.
7 (Recess.)
5 BY MR. CAROME:
g Q What happened, Mr. Roseman, with respect to the
10 drafting of this finding on January 3rd?
11 A • As I just said — (pause) — it was, we either
12 completed the drafting on the 2nd or on the 3rd of January
13 Mr. Sporkin called me in and asked me to redraft the finding,
14 in part.
Q I show you what has been marked as Exhibit 2 .
A Yes.
Q Did you play a role in the drafting of this
Exhibit 2? Do you recognize this document?
A I -- yes, I do recognize the document.
Q What is it?
A What is thi-s document?
Q Yes,
A It's a finding, dated 3 January 86, dealing with
Iran.
And you played a role in the drafting of this.
wmm.
847
ONJa^WFT
WW-. . ^^
is that right?
A Well, what I recognize, really — specifically
what I recognize is the alternative language at the outset
in terms of "essential to limit prior notice" to the
committees or directing the DCI to provide notice to the
committees. That language I specifically recall.
The other language, I have no recollection
between the — let me rephrase that. With regard to the
body of the finding, I don't recall specifically what was
done in the first draft versus the second draft.
MR. CAROME: Could we go off the record for just
a second.
(Discussion off the record.)
BY MR. CAROME:
Q Just so it is clear, you do recall being asked
by Mr. Sporkin to include something on alternative language?
A Yes, I definitely recall that.
Q And when did Mr. Sporkin speak to you about that
subject?
A I am not, I cim not certain on that, but I do know
that — I am not certain when he asked me to draft
alternative language in the finding. The alternative
language dealing with notification to the Congress. However,
I am certain that that subject was discussed.
Q And what did he say on that subject?
wuma,
848
imu^er
1 A Well, he asked me to draft alternative language.
2 Q Did he say why that was to be done?
3 A Well, I don't recall specifically but I presume
4 that the discussion was along the lines of this matter is
5 extremely sensitive and under section 501 of the National
6 Security Act under certain limited circumstances prior notice
7 to the committees is not — may not be required and so we
should draft alternative language.
9 Q You recognize that that was at least highly
10 unusual that not notifying Congress would be contemplated;
11 is that' right?
12 A Well I am not the expert on that subject because,
13 as you said at the outset, we, the Intelligence Law Division,
14 doesn't otdinarily get involved in drafting findings. But
15 my sense was certainly that that was the exception rather
15 than the rule.
17 Q Did Mr. Sporkin indicate who would be the person
18 to choose between the alternatives on the question of
2Q A No, he did not.
Q And with respect to the body of the January 3rd
draft —
A Um hum.
Q — am I correct that what you say is that you
don't have a recollection of what caused these changes to be
849
16
21
m^m
2 A No, I do not.
3 Q You have no such recollection?
4 A That's correct.
5 Q I see that one change is the addition of a
paragraph number 2 referring to obtaining from them
intelligence.
Do you recall where that idea came from?
A No, I do not. In fact, as I said, I don't recall
10 whether, specifically in the body of this, how the final
12 Q You are not sure whether or not you even played
13 a role in the changes between the — to the body of the
14 finding between the January 2nd and January 3rd draft; is
15 that what you're saying?
A I'm not certain. I would assume that I played
17 some role in that.
Q And any changes that are made here are either
19 the result of suggestions or directions from Mr. Sporkin or
20 his own direct edits; is that right?
A That would be correct, yes. I think the way you
22 have just phrased it is the most accurate way of
23 characterizing this.
Q The second line of this, of the descriptive
portion of the January 3rd finding, refers to selected
utmffiL.
850
Uim^HEF
foreign liaison services. Do you know what that is a
reference to?
A No, I do not, except to reference my earlier
statement that I recall that there was a reference made to
Israel.
Q Do you recall any reference to any other
countries besides Israel?
A No, I do not.
Q That same second line of this description of the
January 3rd finding refers to third countries, in the
plural. •
Do you know whether additional countries besides
Israel were contemplated, even if you don't know the
identity of those countries?
A No, I do not. And with regard to the answer I
just gave to you, when you said "selected foreign liaison
services," I'm not certain whether the reference to Israel
was with regard to foreign liaison services or third
countries. It was just possibly a reference to Israel.
Q Other than Israel, you don't know what either the
phrase "liaison services" or "third countries" could refer to,
is that right?
A That's correct.
Q What else happened on January 3rd relating to this
finding that you know of?
ui^lAMlEL
851
mms
41
1 A Again, as I've stated before the best of my
2 recollection, if I worked on the finding on the 3rd, then I
3 continued drafting or redrafting, making suggested — making
4 changes that the General Counsel had suggested; and the only
5 other thing that I know that went on, based on my review of
6 the record, is that the record indicates Mr. Sporkin on
7 3 January brought the finding down to the National Security
8 Council.
9 And when I say the record indicates that, that's
10 a cover sheet that I believe our secretary would have
11 prepared to deal with handling of a Top Secret document.
12 (A document was marked
13 Deposition Exhibit DR No. 3 for
14 identification.)
15 BY MR. CAROME:
Q Mr. Roseman, I show you what's been marked as
Exhibit 3 and ask you is the front page of Exhibit 3 the
18 cover sheet that you just described?
19 A Yes, it is.
Q And that is the source of your understanding that
Mr. Sporkin took this to Mr. North on January 3rd; is that
22 rights
A Yes, that's correct.
Q Do you have any information independent of this
cover sheet that that's what took place? Did Mr. Sporkin
iiMQiiimi.
852
m^^
42
1 tell you that that was going to happen on January 3rd?
2 A I presume that he — he may not have mentioned
3 Mr. North, but I presume that he told me, or me and Mr. Cole,
that he was going down to the White House. I'm fairly
5 certain of that.
6 This reference here in Exhibit No. 3 really
7 confirms what my understanding was, at least insofar as
8 Mr. Sporkin's going to the National Security Council
Q What was Mr. Cole's role in the preparation of
10 the January 2nd and January 3rd drafts?
11 A • Well, as I think I've explained before, Mr.
12 Cole's role was essentially to assist me in drafting those
13 findings, getting his direction from me based on what Mr.
15 Q Did the three of you, that means you, Mr.
16 Sporkin and Mr. Cole, meet together on this matter?
17 A I don't recall that.
^Q Q If we could just briefly review the other pages
19 to what is Exhibit 3. The second page is something that is
20 marked "dummy copy." Do you know what that is?
A A dummy copy is the way we deal with certain
very sensitive documents in our, at least in our OGC
recordkeeping system. In other words, the full text copy
will go to the actual recipient, and may go to some other
recipients, but a dummy copy is put into what's called our
25 recip
llNfiUSSlHEIL.
853
ifflSSIfiS'
43
1 signer files, which is a record of everything an attorney
2 has drafted.
3 A dummy copy would be put into our OGC chrono --
chronology file — would be put into, perhaps, the OGC
5 registry; but it is done so that very sensitive matters are
not spread out, if you will, throughout the office.
Q Does this dummy copy page reflect that any of
materials?
A Well, to me the dummy copy says -- distribution:
original. Colonel Ollie North; ICA subject file, copy 2;
OGC chrono, dummy copy; ILD opinion — if your question was
would I receive that, personally I don't have control over
the ILD opinion files but that would be within my area.
And "GDC Signer" would be Gary Cole, signer.
Q And why was he the signer of this document?
A It could have been one of two reasons. The
secretary could have assumed that he did more of the actual
drafting or the secretary could have simply made a choice
between him and me.
Ordinarily, the secretaries will put the, will
put in the signer --will put a memo in the signer of the
attorney who has done most of the actual drafting. However,
that is not a hard and fast rule.
Q Did Mr. Cole do most of the drafting of the
IIUCltSSKlEL.
854
1 finding? The draft finding on January 2nd, January 3rd?
2 A I think he may have done the actual drafting.
3 I think he may have done a bit more, but I recall it was
fairly equal. We both played active roles in that.
Q And the next pages appear to be, first, the
January 3rd draft, marked "draft"; and the January 2nd
draft, marked "draft"; and the last page is an undated
document which is actually a copy of what appears to be the
g November mini-finding.
10 Is it correct that you did not see this last
■J1 page at any time prior to November 1986?
12 A That is correct,
13 Q Once the finding had been taken down by Mr.
14 Sporkin to the White House, did you hear anything more about
15 the finding?
,|g A To the best of my recollection, I did not.
17 Q Do you recall speaking to Mr. Sporkin about the
13 finding at any time after it had been taken down to the
White House on the 3rd?
A No, I do not recall having done that.
Q Did you ever hear anything in January or February
of 1986 about whether or not the finding you had worked on
A Certainly not from Mr. Sporkin and, no, nothing --
when you say did jab^^tf^^VViVIPtrfV'^^^^ nothing. The
mmm'
855
m^ms!^
only subsequent discussion or discussions that I would have
had on that would have been with Mr. Cole and with Mr.
Makowka when Mr. Makowka returned from — he was either on
leave at that time and/or had been ill. And when Mr. Makowka
came back I'm certain that I briefed him on this, and I'm
certain that Mr. Cole and Mr. Makowka and I on one or more
occasions among the three of us said has anybody heard
nobody knew anything more. Certainly Mr. Cole and I didn't.
Q Did you ever ask Mr. Sporkin , "What happened with
respect to the finding we had worked on"?
A I don't — I do not believe that I did.
Q Were yofl^tware of «5^eting« tSat vxe g^g on
on the subject of providing arms to- Iran during "January
•86? " - ■ = ' - J:.
out 0^he offi«e-f<^^ period of
A Yesf there was
Q And what were the dat«»- that you were out of the
office? , :-^ '^^^ "1_.5"- -^ -^ ~.
A z- WelV I'm at_l,iftAt: certeni^that t--**«« o^t of the
office the week of 6 Jairaary. ^-^^
a_ iFoxL.All of that week? _.r
A YesT --- "^
856
m^im
1 Q Were you aware that Mr. Cole participated in
2 meetings on the subject of the finding and related matters
3 during that week?
A Yes. I was subsequently made aware of that.
Exactly when I don't recall, but subsequently I was made
aware of that.
Q And what did you learn about those meetings or
meeting?
9 A Well I had a copy -- well let me backtrack.
10 When the — after November of '86, when the Iran
11 initiative became public and we received requests from
12 various, you know, the Independent Counsel and the
13 committees to review our files for documents, at least at
14 that point in time I reviewed my files, of course, and one
15 of the documents that I located in my files was a draft of a
•jg memo-, which I believe was dated 6 January 86, from Betty Ann
■J7 Smith to George Clarke, on arms transfer.
■^Q Q And you understand that that was the subject or
ig a subject at the meeting or meetings that Mr. Cole
participated in the week of January 6th?
A I am not certain but I believe that it was.
Q Did you have any discussions on that subject
during January of '86?
A No. In fact, you know, what may have happened
was that when I returned the following week Mr. Cole may have
liliiciji.OTm„.
857
ONtmEifiT
1 given me a co^^^' that memo and indicated tliat he was
2 involved in a follow-up meeting. I probably retained that
3 memo because it was of interest to me, the legal analysis on
4 foreign military sales, not in terms of any Iran initiative.
5 I retained that document I am certain just because it had
6 reference to statutes and some legal analysis on a number of
7 different statutes.
Q In any of your discussions that you participated
9 in in January of '86, were you ever told that freeing hostages
10 was one of the objectives of the activities to be undertaken?
11 AT don't believe so.
12 Your question was, was I — could you go over
14 Q The question was, did you ever learn in
15 January of '86 that freeing hostages was one of the
16 objectives of the finding?
A No. I don't believe that I ever learned that.
Q In January '86 did you ever come to learn what
the NSC's relationship to the finding was?
A Other than what I have previously stated here
Q I'm not sure of what you're referring to.
A Well, in other words, knowing that Mr. Sporkin
brought the finding down to the National Security Council,
other than that fact, no, I have no — I was not told about
iiiiicysfiigj^&».
858
imssRi^
1 what role the NSC may have played in all of this.
2 Q The activity that kept you out of the office
3 during the week of January 6 was a management course; is
4 that right?
5 A That's correct.
Q And not only did you hear nothing more about the
findings that you had worked on in early January, you also
heard nothing about a January 17th, 1986 finding; is that
9 right?
10 A That's correct; I heard nothing about that.
11 Q ■ Do you recall writing a note to Mr. Makowka on
12 the subject of the drafting of the finding in early January?
13 A I can't recall specifically having done that;
1^ however, when Mr. Makowka would be out of the office for a
15 period of time, say, several days or a week, if I for some
reason was not going to be in the office on the day he
returned, my ordinary practice would be to dictate a note to
the secretary, just going over a whole list of all of the
activities that came to our division in the last few days
or in the last week or in the last month, however long Mr.
Makowka might have been out.
-_ In fact, prior to my interview with Mr. Woodcock
I had thought of that. That there might be something in that
secretary to review division files, review her own, you know.
IINiHMlfJL.
859
nR»$smT 1 her own files. She even reviewed her own steno notebook and 2 she couldn't find any such note. So I may have written one 3 and I may not have. 4 Q But you're satisfied that an adequate search 5 has been done for that and one wasn't located; is that right? 6 A Yes, I am satisfied. 7 MR. FEIN: Could I interrupt for just one second and go off the record; g (Discussion off the record.) 10 BY MR. CAROME: •J1 Q ■ Other than the drafts of the findings we have 12 already looked at today 13 A Um hum. 14 Q — are you aware of the existence of any 15 documents that relate to the drafting work in early January; ^g A Drafting work on these findings? 17 Q That's right. A No, with the qualification that I indicated earlier, that Mr. Cole and I had used some other background- type of papers to assist us in drafting these types of findings. But that's the only other. Q Did you take any notes of your discussions with Mr. Sporkin? A Yes, I did. Q And did you keep those notes? llIiltliOTElL 860 mi^tiir 50 A No. I would have discarded those notes pretty - at the time we drafted this or pretty shortly thereafter. Q Was that because Mr. Sporkin said something about not keeping papers on the subject? A No, he said nothing of that sort. He said absolutely nothing of that sort. That was just a matter of practice, if you will. Just taking notes down on what -somebody is giving instructions on and doing the assignment, and the notes have no independent value. There was nothing unusual in discarding those notes in connection with this particular matter than in connection with any other matter I would have hemdled. 861 T5 ] c\ci,es S I —- S 3i '^ 862 IJiKIASaElii&T 1 2 3 Q Let me turn back to the point at which you became 4 involved in drafting the January 1 — excuse me — January 2 5 and 3 finding. I was not present at the beginning of this 6 deposition but I recall from our interview that as a member 7 of the Intelligence Division of the Office of General Counsel 8 it was not a usual thing for you to be involved in the 9 drafting of a finding; is that correct? 10 A That's correct. 11 Q' And when you had this task brought to your domain 12 you sought guidance from earlier findings; is that correct? 13 A 'That's correct. 14 Q Had you known about a November finding on the 15 same subject, then, presumably, you would have used that as 1g well; is that correct? 17 A Presumably we would have. 1g Q But you did not use that, is that correct? A We were not aware of the November finding and we did not use the November finding. Q Let me turn to the two findings that have been 22 marked Deposition Exhibits Nos. 1 and 2. If you would direct 23 your attention to both of those. 24 The finding that is dated January 3, Deposition 25 Exhibit No. 2, contains a reference to providing training l^MHiSSlElEll 863 BH8R^»T 55 and guidance to the moderate elements. Do you have any understanding as to what that meant? A No, I do not. Q That does appear to be a change from the previous day's effort, but I gather you have no understanding as to whether that meant U.S. personnel might go to Iran or what they might be training the moderates to do? A No. I have no understanding of what that term meant. Q Do you have any idea where it came from? A ' It could have come from another finding that Mr. Cole and I had used as a -- used in assisting us in drafting this. It could have been Mr. Sporkin's addition. Those are two possibilities. Q You have no independent recollection, however, I gather? A No, I do not. It could have been Mr. Sporkin saying to us add in the word "training" or making some suggestions, but I have no recollection on that at this time. Q The January 3 finding. Deposition Exhibit No. 2, also uses the term, in the second paragraph, "establish contact with the moderate elements." A Um hum. Q At the time this finding was drafted did you have any understanding as to whether contact had already been made 1 ng as to whether contact naa llUtUSSlBQL 864 ^KSStPKlT 56 1 with the moderate elements or whether this was something 2 prospective? 3 A My best recollection would be that this was 4 prospective. 5 Q And what would you base that recollection on? 6 A I base that recollection on the language of the 7 finding here. I would really be purely speculating if I said 8 that, you know, in my discussions with Mr. Sporkin that he 9 had indicated that there had already been any contact. I 10 have no recollection of that. 11 Q ' You, I believe, probably were already asked this 12 in the deposition but let me — 13 A Let me just clarify that last point. Obviously, 14 the discussions went along the lines, something along the 15 lines of we are trying to establish, establish initiative, •jg something along — you know, or we had tried to make efforts to do this. Q When you say obviously, you're gleaning that from 19 the language of the finding, I gather? 2Q A Yes, I'm gleaning that from the leuiguage of the 21 finding. 22 Q Did you have an understanding as to whether the arms and equipment that are referred to in Deposition Exhibit No. 2 refer to any particular kinds of arms; whether, say, anything from handguns to missiles were contemplated? llNOii^ElElL 865 isj^ffir 57 A No; I don't believe that any of that was discussed with me. Q The initial finding that was drafted — A Urn hum. Q — Deposition Exhibit No. 1, refers to providing arms to the government of Iran. That contrasts with language in Deposition Exhibit No. 2 that refers to providing arms to the moderate elements. A That's correct. Q Did you have any understanding as to how you could provide arms to the moderate elements that would not ipso facto be provided to the government of Iran? A No, I had no understanding of that. And in fact, that particular point puzzled me and I recall discussing that with Mr. Cole, and I recall that it puzzled him somewhat, too. Q Let rae try and sharpen the point a bit. Presumably, if something as low power as handguns are being provided, then you might be able to provide those to a moderate faction within Iran and not have it go to the government of Iran; is that correct? A I would be just — I would merely be speculating on that. Q Okay . A I'm not an expert on the Iranian hierarchy. tiiiiciiiimiL. 866 m«5Si«iir 58 1 Q I understand. I'm trying to make a point of 2 contrast here. 3 If, however, you provide a missile or a series 4 of missiles, that's the kind of item that it is going to be 5 hard for a moderate group to hold unto themselves, just in terms of common sense. Would you agree with that? 7 A I would have to agree that it would be more 8 difficult to deal with a missile than with a handgun. Q Okay. Now the reason I asked for that, or tried 10 to make that contrast is to see if that would assist your 11 recollection in this conversation that you had with Mr. Cole 12 as to why it was that you thought there would be a problem 13 providing weapons to a small faction that would not ipso 14 facto go to the government. .^5 In other words , did you have an understanding as 1g to what kind of weapons would be involved, given that you ■J7 focused on that problem? .fg A It's possible that we did but I think unlikely, ^g and certainly now I have no recollection of that. I might add that you talked about common sense before and that, you know, it may have been that at the time common sense led us to think that if this was being used in an Iran-Iraq conflict it would be more than handguns. Q That certainly would be an exercise of common sense. ^^.^nwlifc^Wfe 867 iaisw A Yes. Q The January 3 finding has the alternative language in it, which you have recognized, on notice to Congress. A Um hum. Q It contains in the first alternative a delay of notice by the President until he shall otherwise direct. Is that right? A That's correct. Q Now, if the law requires that a finding, notice of a finding can be delayed, however, Congress is to be notified in a timely fashion; is that your recollection of the law? A Section 501 states that Congress will be kept fully — currently informed of intelligence activities which specifically include significant and anticipated intelligent activities, which under the Hughes-Ryan amendment includes covert action or special activities. The law then says that — and it uses this language. If says, if — well it says, I believe, in extraordinary circumstances where it's — in extraordinary circumstances to protect the vital interests of the United States where it is essential to limit prior notice, prior notice may be limited to, or notice may be limited to, and there are eight senior officials in Congress: the chairman. ii^ii;^^^ UlffiEASSIFISlT 60 1 you know, ranking minority member of the Intelligence 2 Committees and four others. 3 But there is another section of another ~ I 4 believe it's Part B of that section of the National Security 5 Act that says, if there has not been — if the President has 6 not provided the notice as required under subsection (a) , 7 which was the section I was just referring to, the President will provide a timely — a full report on a timely basis to 9 Congress of that. 10 Q The reason I asked that question is that the 11 formula used in this first alternative, which is "until I 12 otherwise direct," is really quite indefinite in the time 13 period. 14 Do you recall where it was that particular 15 formula came from? 1g A No, not specifically. I do know that Mr. Cole 17 and I reviewed the National Security Act very carefully to 18 make certain that this alternative language was consistent 19 with the requirements of the law. Again, I am — this is speculation, but it may have been that Mr. Sporkin asked that that language be put in or it may have been language that Mr. Cole and I drafted ourselves. Q Do you think leaving it that indistinct is consistent with the law? lICLiSSlEiti 61 A I beTieve'tliat this was consistent with the law when we drafted it, as I said earlier; and as I have just said, we made every effort to review the statute and ensure that this type of language met the requirements of the law. And there was nothing in here, or there is nothing on the face of this nor nothing that was brought to our attention at that time that would have indicated that notification would have been — notification" would not. have been provided for a period of time. Q Is it your understanding that notice can be delayed indefinitely? A As yott two gentlemen have pointed out earlier, we are not the experts on special activities and covert action in Intelligence Law Division, so I would have to defer to other — others in my office who have that responsibility and that expertise on that precise question. Q So the answer would be you're not really sure, is that correct? A I would rather let my answer stand as I have just stated it. Q There is another point of comparison in these two exhibits. Deposition Exhibit 1 and Deposition Exhibit 2, that I'd like to draw your attention to. The final paragraph of Deposition Exhibit No. 1 provides that the^ asaistanre^ smd the^ is a wide variety of 'mi r ^jn i g^ ^ iwn 870 URBEIiSStPtllT 62 1 existence, to Iran will be terminated if the U.S. Government 2 learns that this materiel is being used for purposes other 3 than the furtherance of Iran's war effort against Iraq. 4 That language contrasts with language in the 5 second version of the finding, January 3, which states that 6 these materiels are limited in their use essentially to the 7 Iran-Iraq conflict. This assistance will beycontinued if 8 the U.S. Government learns that these elements are misusing 9 or intend to misuse this assistance for the purpose of 10 reinstituting terrorist actions against U.S. persons, 11 property or interests, or otherwise. 12 Do you recall how that transformation occurred? 13 A No, I do not recall that. 14 Q Did you have any understanding at that time as to 15 whether, if the moderate elements used this materiel to, say, 15 repel a Soviet invasion, that that would have been considered 17 inconsistent with the purposes of this Jinding? ig A I'm sorry. Repeat that question, please. 19 Q Had the Iranian moderate factions used the 20 materiel that they were going to receive under this initiative 21 to repeil, say, a Soviet invasion, would that have been 22 inconsistent, in your view, with the purposes expressed in 23 either of these two documents? «. A We really did not discuss any hypotheticals or 25 ^"y scenarios at that time as to when the assistance would be IIMCliRRlEP. 871 « cut off. I do recall that, you know, a clear thrust of this was to help prevent terrorist acts against the United States, against U.S. citizens, U.S. property, any U.S. interests. Q What I'm driving at with this question, and hoping perhaps to refresh your recollection on the point, if there was conversation on this point, is whether the Soviet Union was considered to be a military threat that needed to be addressed in either of these documents when you were called upon to draft them? A I do not recall that the Soviet Union was discussed with regard to either of these documents. Q In any way, shape or form, is that correct? A That's correct. MR. CAROME: Tim, can I follow-up with something on that sentence? MR. WOODCOCK: Yes. FURTHER EXAMINATION ON BEHALF OF THE HOUSE SELECT COMMITTEE BY MR. CAROME: Q That last sentence in the January 3rd version of the finding, which is Exhibit 2, refers to reinstituting terrorist actions. Was there any discussion to the effect that the elements receiving these weapons had previously engaged in terrorist actions? A Well, if you're referring to Deposition Exhibit ** TTOlAwi l Jpt P lP« T k 872 1 No. 2, and you just said the elements receiving these weapons. 2 I, to my knowledge — I mean, I have no knowledge that prior 3 to this finding anyone was — any moderates or anyone in the 4 Iranian government were receiving any weapons. 5 Q No. My focus is on the word "reinstituting , " which seems to suggest that there had been terrorist actions and the goal here was to avoid reinstitution of such terrorist actions by these people. And it seems to be that 9 the reinstituting under discussion here is by the elements 10 receiving the weapons. 11 And I am wondering if you can recall, having 12 focused on this point, any discussion on the question of 13 whether or not the elements receiving these weapons had 14 previously engaged in terrorist acts. 15 A It's possible that there was discussion about 15 dealing with moderates who were acting somewhat more 17 moderate now, somewhat more civilized. But again, to say that that kind of discussion went on with any kind of 19 certainty is pure speculation on my part. Q You said that you came to understand at this time that one goal of the activities contemplated was to control or stop terrorism; is that right? A That's correct. Q Now that goal doesn't seem to appear — I withdraw JUSSL 873 mmm 65 A Yes, that is — I believe that is stated in both findings. Q And do you recall what Mr. Sporkin said about how the reduction of terrorism fit in with the activities contemplated here? A Not specifically. I think I've, you know, answered that in terms of that there was an interest there in curtailing terrorist activities against the United States. FURTHER EXAMINATION ON BEHALF OF THE SENATE SELECT COMMITTEE BY MR. WOODCOCK: Q ■ Do you recall any discussion of having any commercial entity or private citizen play a role in the transferral of weapons or the acceptance of monies from Iran and putting this policy into effect? A No. I recall no such discussion. Q Did you have any understanding as to whether the United States was going to deal directly with Iran or was going to use any kind of a screen in its dealings with Iran? A No, I do not, other than to reference my earlier statements about recalling that there might have been a reference to Israel. But other than that, no discussions of third parties. I'm fairly — I'm very confident that there was no discussion of private U.S. persons or U.S. groups or corporations being used to channel this. Q Or private citizens from any area of the world? I IvURITb X^Drfwi t*t 874 URcuSSSflHW^ 66 A Or private citizens; that's correct. MR. WOODCOCK: I don't have any more questions. FURTHER EXAMINATION ON BEHALF OF THE HOUSE SELECT COMMITTEE BY MR. CAROME: Q Just one small point — A Sure. Q — to clean something up. You talked earlier about a1 finding that had been worked on in late 1985, isi that right? A Yes. Did you ever learn whether or not that finding was signed? A No, I never learned the result of that finding either. MR. CAROME: I don't have anything more. We can go off the record. (Whereupon, at 3:02 p.m., the taking of the deposition was concluded.) WU&ClflCJi,^ 875 .^/ f mf 2^^^<^ ion 652 -gn Assisr ancg Act of ig^i' -ea, _Concer n J nq Opera c Ion r jTnci Ot.'er tJ •pepoi e^L.u -1- SCOPE Iran DESCRIPTION foreign liaison f^vfJ^' f"*^ r^'^ selected government en?Ue to iclenJif;^ '°f'^^" r::s:;nri?fr"T^"v"----'---"ve ??:ti".r:n:;; :;:::.;";;.,"• -"».'.-:'o, The White House '•'ash ington, O.C. ■'ate: 2 January 1986 Uki CXxaJ ^//f - S t C RE 876 : DEPOSITION ? EXHISIT I -hit --^2. Finding PurBU«nt to Stction %%\ r rnn TT»TM^Tm-mT7 iTTn »nLi3j jEm iji3iirhm-prTiT?rTT«'i ^T T» in f^ ;TrrwnT7T-rT-gT:>r>rMfT DRAFT I b«c«by find that tht following operation in a fortign countcv (inclading all support nacaaaary to such operation) ia importLnt to th« national aacurity of tha Onltad Stataa, (and due to^ts aitraaa^aansitivity and aacurity rlaka, I dataraina it ia aMontial'tb Halt prior notica, and dlract tha l^iractor of Cantralvlntallifanca to rafrain from reporting thla Finding to tha Congress «s provided in Section SOI of the National Security Act of 1947, aa amended, until I otherwise direct.] -or- (and direct the Director of Central Intelligence, or his deaignec, to report thia Finding to the intelligence conittees of the Congreas purauant to Section 501 of the National Security Act of 1947, aa aaended, and to provide auch briefings as necessary.] SCOPE Iran )E^ DEiOtlPTIOH Work with Iranian elemeAts, groups and individuals, selected foreign liaiaok servicea and third countries, all of which are ayapathetic to O.S. Governaent interests and which do kot conduct or support terrorist actions directed againat O.S. persons, property or interests, cor the purpose of: (1) establishing a aorC aoderate governaent in Iran, and (2) obtaining f roa kbea aignificant Intelligence not otherwise obtainabW,-^o deteraine the current Iranian Governaent 'a intentiona with respect to its neighbors and with respect to terrorist acts. Provide funds, intelligence, counterintelligence, training, guidance and coaaunieations aasistance to theae eleaents, groups, individuala, liaiaon aervices and third countries in support of these activities. EsUblish contact with the aore aoderata eleaenta within and outside the Governaent of Iran tb eatablish their credibility with that Governaent by pM provision of eras, equipaent and related Matarlel to these eleaents on condition that these aateciV* ^« Halted in their use essentially to the Iran- Itaqi conflict. This asaiatance will be diac«)tinued if the O.S. Governaent learna that theae eleaabts araj Blsuslng or intend to aisuse this aaai/Unce, for the purpose of reinstituting terrorist actions against O.S. persons^, property or Interests, yhr otherwise. The White House Washington, D.C. Date: 3 January 1986 ■'^y ^^tetrJjEIlaJ^^ 877 878 UL" AS:";f!Ei d::-S6-5oo3i 3 .'a.-uary 198 6 D U M M C p Y The White House Washington, D.C. Date: 3 January 1986 Distribution: Original - Col. Oil North (copy 1) 1 - ICA Subject file (copy 2) 1 - OGC Chrono (dummy copy) 1 - ILD Opinion file -(dummy copy) 1 - GDC Signer (dummy copy) OGCR TS 0801-86 copy 1 r ^ -» Partially Declassified /Released on.^^^i^-:i]li'] under provitjns of E.3. 1235?^ by S. Reger, f;:tiGr!a! Security Council djxv^//; lji?si/iioifl£ 879 UUiimodii c^ <W>'^'^ xf^ Pr^.Jinq Pursuant to Section 662 of ^.■^>_"^^ T.-.e Poreign Aaslatance Act of 1961 -cN-^- , .v,v"' . :;^'' ^ wPdertancn py tr.t Central Intelligence i'^ aC'''^.,Av'*^ " Agency in Poreign Countries, Ot.-er BRAFt 3 ^\ - J^"'''" ,j,\v"''' Those Intended Solely for t^.e Pjrpcse ■^"'' "■■ <:^ of Intelligence Collection I hereby find that the following operation in a foreign country (incl-ding all support necessary to such operation) is irportant to t.-e national security of the United States, land due to Its extrene sensitivity and security risKs, I determine • t IS essential to li.-nit prior notice, and direct the Director of Central Intelligence to refrain from r eporting this Finding to the Congress as provided in Section 501 of" t"he~ Nat ional Security Act of 1947, as amended, until I otherwise direct,] -or- [and direct the Directoc of Central Intelligence, or his designee, to report this Finding to the intelligence conunittees of the Congress pursuant to Section 501 of the National Security Act of 1947, as amended, And to provide such briefings as necessary. ) SCOPE DESCRIPTION Iran Work with Iranian elements, groups and individuals, selected foreign liaison services and third countries, all of which are sympathetic to U.S. Government interests and which do not conduct or support terrorist actions directed against U.S. persons, property or interests, for the purpose of: (1) establishing a more moderate government in Iran, and (2) obtaining from them significant intelligence not otherwise obtainable, to determine the current Iranian Government's intentions with respect to its neighbors and with respect to terrorist acts. Provide funds, lntelliqenc«, counter in:elligence, training, guidance and communications assistance to these elements, groups, individuals, liaison services and third countries in support of these activities. Establish contact with the more moderate elements within and outside the Government of Iran to establish their credibility with that Government by the provision of arms, equipment and related materiel to these element* on condition that these materials be limited In their use tsaentlally to the Iran-Iraqi conflict. Thla aatlitance will be discontinued if the O.S. Government learns that these elements are misusing or Intend to aliuse thia assistance, for the purpose of rtinstltutlng terrorist actions against O.S. person*, property or Interests, or otherwise. The White Bouse Washington, D.C. Oats: 3 January <^xr/j^//S' 880 i^ \v- 3|»c^f; ^~ri i^ As •■-ed, Cone <v^^ ■sse r-ten^Trt ^ ■"■ - t o Section 6g 2 o 196 rninq Opera t ion 3 t-ent.-al In telirjin ce 1 .- e r T ^^ITTT [r. Coun tr i SoTeT^ T^ an gence Col, • e P u r so s e ion •ry (including all ■ •-port ant to trie national t^e following operation sjppcrt necessary to SCOPE Iran DESCRIPTION work with individuals and organizations both foreign liaison services, and other foreign government entities, to identify, develop and promote the advancement of moderate alternative leaders in Iran. Provide intelligence, counterintelligence, communications assistance and funding to the identified potential alternative leaders to promote the ?r.'n^\'f rr' °^* """^ moderate government in Hif2,-r^ "^ "''"" ^^' threat of terrorism directed against U.S. persons, property and interests. Protect and support these operations by conducting a program of deception, unilaterally and through third countries, which may include the use of all torms of propaganda. Provide arms, equipment and related materiel to the Government of Iran to assist in its military operations against Iraq in order to encourage to curtailment of terrorist activity directed against U.S. targets and interests. This assistance will be terminated if the U S Government learns that this materiel is being ased for purposes other than the furtherance of Iran's war effort against Iraq. The White House Washington, D.C. "■ate: 2 January 1986 <:ZxrAJ ^//^ (^ 881 Fi ndmq Pur s-ar: to Sec tior 1 662 of f-e For e A3 s : s tance Act of 1561, AS Ar.e-ded. Cor, cer n C = era t ions V-der ta«.e- = Y -■ e Ce' '. t r a 1 In tel i<^e.- ce Ac e r c V ; -. F or sign Co.- t r .es ;, ct^ ■er T ' a n - se : - te-ded Sc lely for f-e Pur 00 se of Ir. te ence LZ . .ect:on I .'■.ave Seen 5r:efed on t.-.e efforts being rrade by private parties to obtain t.-.e release of Americans held hostage in the Middle East, and hereby find that the following operations m foreign countries (including all support necessary to such operations) are important to the national security of the United States. Because of the extreme sensitivity of these operations, m the exercise of the President's constitutional authorities, I direct t.T Director of Central Intelligence .lot to brief the Congress of the United States, as provided for in Section 501 of the National Security Act of 1947, as amended, until such time as I may direct otherwise. Icstage Middl. Reset ! East Part ially Declassifi"; 'iv.te: p.v by :. R=;er, ' ;oie3Sc(i craaVM^'^'ti DESCRIPTION The provision of assistance by the Central Intelligence Agency to private parties in their attempt to obtain the release of Americans held hostage in the Middle East. Such assistance is to include the provision of transportation, communications, and other necessary support. As part of these efforts certain foreign material and munitions may be provided to the Government of Iran which is taking steps to facilitate the release of the American hostages. All prior actions taken by U.S. Government officials in furtherance of this effort are hereby ratified . The White House Washington, D.C, drx/y "^/^o m^m^^ 882 £r&NOGRAFHIC MINUTBB ijiiravlse Not for I iEr^ %;< /87 rm-nfc ' ifiF I — COPIES UJS. ^yUSE OF BEPBESENTATIVBS t W Partially Declassified/Released on. under provisions ol E 12356 V^ by K Johnson National Security Coi •l-l an85 omci OP ra> CLBK OflMiCOadal yHClASMB....^-^- 884 Dotson/drg Take #1 BNttASStPKlT DEPOSITION OF WILLIAM PAUL ROSENBLATT Friday, September 25, 1987 U.S. House of Representatives, Select Committee to Investigate Covert Arms Transactions with Iran, Washington, D.C. The committee met, pursuant to call, at 9:10 a.m., in Room B-336, Rayburn House Office Building, Pamela Naughton presiding. Present: Pamela Naughton, on behalf of the House Select Committee. Robert Genzman, on behalf of the House Select Committee. Thomas McGough, on behalf of the House Select Committee. Also present: Elizabeth B. Anderson, on behalf of the Partially Declassified/Released on /4J<^fV ■ 88 under pfovisions of E 12356 by K Johnson. National Secutity Council Witness • MBm VLJBWl I If IMLff Ifl DNfiEASSIffir' Whereupon, 2 WILLIAM PAUL ROSENBLATT, 3 was called as a witness on behalf of the House Select Com- * mittee and having been duly sworn, was examined and testified 5 as follows: 6 EXAMINATION BY COUNSEL FOR THE HOUoE SELECT 7 COMMITTEE 8 BY MS. llAUGHTON: 9 Q Could you state your full name for the record. 10 A William Paul Rosenblatt. R-o-s-e-n-b-l-a-t-t. 11 Q Could you state your title please? 12 A Assistant Commissioner Enforcement, United States 13 Customs Service. 14 Q My neime is Pamela Naughton, Staff Counsel for the 15 House Select Committee to Investigate Covert Arms Trans- 16 actions with Iran. I would ask those present in the room 17 to state their names and title. MR. MC GOUGH: Thomas McGough, Assistant Counsel to the House Select Committee. MR. GENZMAN: Robert W. Genzman, Associate Minority Counsel to the House Committee. MS. ANDERSON: Elizabeth Anderson. I represent Mr. Rosenblatt. BY MS. NAUGHTON: Q Now, Mr. Rosenblatt, we interviewed you a while Hvlib Afflfiit w&F 886 UNSaSHREfl^' 1 ago on basically three different areas, and I want to go 2 through those in perhaps a little more detail today. Hope- 3 fully, we can take these areas chronologically, but complete the subject matter before we turn to another. The first issue I would like to turn to, and I hope this is the correct chronological order, is the Maule Aircraft investigation, and it is M-a-u-1-e. If we can start with a couple preliminaries first, could you tell us in your capacity what your functions are at Customs? 10 A As the Assistant Commissioner for Enforcement, I 11 am responsible for all enforcement investigative matters as 12 it relates to the jurisdiction authorized by the Customs 13 Service in various United States codes. There are approximate- 14 ly 4 00 laws that we enforce. 15 Q This enforcement would include criminal prosecutions: 16 A Criminal and civil, yes. 17 Q Now, prior to the investigation concerning Maule fg Aircraft, did you have any contact with Colonel North? A No. 2Q Q Could you tell me how this particular investigation 21 came to your attention? A Approximately middle to latter part of August, maybe even beginning of September, I had occasion to be in the Commissioner of Customs, William VonRabb's, office, at which time he mentioned to me that he had a conversation with ImlwwWKfh^ 887 WiSSKIilT ^ Colonel North relative to an inquiry made by Colonel North 2 on Maule Aviation, and the way the Commissioner put it to 3 me, that according to Mr. North, or Colonel North rather, we ^ were being very heavy-handed in our investigative pursuit 5 of the case in the Atlanta, Georgia area, and, therefore, 6 the Comiiiissioner wanted me to look into it to determine 7 whether or not Colonel North's contentions were accurate or 8 not. 9 Q Did the Commissioner tell you what Colonel North 10 had told him? 11 A In substance. I don't believe in verbatim — the 12 Commissioner and I do not operate that way that we would 13 state verbatim the conversation. 14 Q Did the Commissioner tell you Colonel North's 15 concern was over the substance of the investigation or of the 16 manner in which the agents were going about the investigation? 17 A The manner in which the investigation was being 18 conducted. 19 Q Exactly what do you mean when you say manner? 20 A In other words, being too aggressive in conducting 21 their investigation. 22 Q Where was the investigation taking place? 23 A I believe in what I consider the Atlanta, Georgia 24 area. 25 Q Which region is that for Customs? umiissKm wsmm 1 A The Southeast Region. 2 Q Who is the Customs person in charge of the South- 3 eastern Region? 4 A The Regional Commissioner is George Heavey. 5 Q Would you spell that? 6 A H-e-a-v-e-y. 7 MS. ANDERSON: At the time. 8 THE WITNESS: Oh, at the time? Edward Kwas at 9 the time. 10 BY MS. NAUGHTON: 11 Q Could you spell that, please? 12 A Edward and then K-w-a-s. 13 Q Do you know what Commissioner VonRabb's relation- 14 ship had been with Colonel North up to this time? 15 A No, I don't. 1g Q- Did the Commissioner ever speak to you about Colonel North's involvement or connection with General Singlaub? 19 A Not that I can recall. 2Q Q Do you recall any discussion of a helicopter 21 purchased named Lady Ellen? A That I recall. Q What can you tell me about that? A Apparently, there had been some conversation between 25 the Commissioner and either General Singlaub or possibly 17 itNiliSSMEft' Colonel North, I am not sure which, relative to the Lady Ellen. Customs had detained the helicopter in the South Florida area, I believe Fort Lauderdale. We were determin- ing, based on that detention, whether or not State Department had issued a license for the exportation of that helicopter. We subsequently determined that it had not been, a license had not been issued, and, therefore, the Commissioner was advised of that, and I believe General Singlaub was subse- quently advised, I did not personally advise him, I don't know who did, that a license was required. I subsequently found out that a license was issued for the exportation of that helicopter by, I presume. General Singlaub. Q The exportation office, not the issuance of the license? A The license was issued for the exportation of the helicopter. Q Do you know what Colonel North's connection was to this helicopter? A No, I do not. Q Do you know if he communicated to the Commissioner the desire for a license to be issued? A No, I do not. Q Do you know if he had any input? A I do not. iiMpL nooinrn 890 UNSHSSWHT Q Now, could you tell us how it is the Maule investigation began, what precipitated the investigation? A To the best of my recollection, I believe it was CBS News had a segment of a news broadcast wherein it inter- viewed a pilot who claimed to have ferried aircraft from Maule toJ The Department of Justice was watching this iV broadcast, and on the basis of this broadcast, requested Customs to conduct an appropriate investigation. Q Were they ferried into^^^^^^|or into Nicaragua Q At any rate, one of the things you wanted to determine from the investigation was whether or not it had been ferried into eithei^^^^^^^or Nicaragua? A That is correct. Q Was Joe Tafe the person at the Department of Justice that asked Customs to look into the case? A I am not absolutely positive. I know in our initial discussion, I probably used the name of Joe Tafe, since that is the individual I am most familiar with over at the Department of Justice, to get involved in these matters It could well have been some other individual. I wouldn't 891 necessarily know that detail because it would come over in writing and go directly to our Strategic Investigations Division. Q Now, what kind of aircraft was it that was the subject of this investigation? A It was my understanding the«-e were — nomenclature was Super Piper cubs or Seneca Piper aircraft. Q Can you tell me what type of aircraft that is? A I am not absolutely positive, but I gather they are single-engine high-wing aircraft. Q Now, could you tell us precisely what violations of law would Customs be looking at in this type of investigation? A Basically, there would be two segments or sections of law we would be concerned with: one. Arms Export Control Act, whereby these aircraft would have what we call military hard points that require a State Department License; secondly, whether or not there was some special equipment on it, such as a STOL kit, S-T-O-L, which stands for short takeoff and lemding equipment, which would require a Commerce Department license. Looking back on this, of course, there is also the aspect of a foreign asset control license to an embargoed country such as Nicaragua. We were fairly confident right from the inception that the aircraft was practically in- capable of having what we call military hard points put on it, HbIvi) AAKfEiEuT 892 25 llflliU^Mr not beyond the realm of possibility, but not probable, 2 because of a variety of technical aspects. So, basically, 3 we were dealing with two areas, whether or not it required a 4 Commerce license or — and/or required a license from the 5 foreign assets control because of an embargoed country. Q Also, if on the form the actual point of destina- tion was erroneous, in other words, if the plane actually was intended to go or did indeed go to Nicaragua but a 9 different end-user or different point of destination had 10 been put on the government form, would that also have been 11 a falsifying? 12 A Yes, we could have gone after that too. 13 Q When you say hard points, would such a hard point, 14 for instance, be a gun mount? 15 A Yes, that would be correct. 18 Q After Commissioner VonRabb asked you to or told you 17 about his conversation with North, what did he ask you to do 18 about it? 19 A Just to look into it and ascertain whether our 20 people were being over-aggressive about the investigation, 21 and the general nature of our investigation and our pursuit. 22 Q And did you call Colonel North? 23 A I did later that day, the same day. 24 Q Had you spoken to him ever before? A No. UNCLASSIEIEj). UNtnm!^^ 10 Q What did you tell North when you called him? A That I was calling him in connection with his conversation with the Commissioner relative to the Maule investigation. At that time, he thanked me, and he indicated that our people were being very aggressive and were asking for all kinds of records from Maule relative to the shipment of these aircraft. He indicated at that time that the Maule people were good guys and that we were basically, these are my words, not his words, that we were barking up the wrong tree. At that time, I indicated, I said, well, are our people being overly-aggressive, or exactly what was wrong with our people's conduct? And he said, no, you know, our people had been courteous, but that we were demanding all kinds of records from Maule, and I indicated to him, I said to him, look, the easiest way for us to determine any violations of law, and I went into the potential violations of law as I have already done with you on the exposure and what we needed to do was get documentation as quickly as possible and photographs of these aircraft so we could determine whether or not there was a STOL kit on these aircraft, which would require a license, and also shipping documents and invoices, purchase orders relative to these four aircraft. It was at this time, he indicated to me that one Hmn^iFiPfiT BNRIffifffBT 11 of the aircraft had crashed, it was located and that the other three were over^^^^^^^^| being used for shipments of medical supplies and other humanitarian purposes. And I said, well, if that's truly the case, then we would be able to clear this matter up rather rapidly if he could provide me, since he had offered to provide me, the documentation that I had enumerated earlier in my conversation with him. Q Well, did his volunteering of the information that one had crashed and two were ^^^^^^^^H and so forth — A Three . Three were ^^^^^^^^B A Yes. Q - Were any i A One crashed Q Did he say it crashed A The best Z can remember, it crashed and was in Whether crashed in^^^H^Hor can't tell you. Q Did he impart this information to you during that very first phone call you had with him? A As best as I can recollect, yes. Q My notes of our interview indicated that he volunteered that information to you at a subsequent a total of four. rtiJHlitl HwilTffnhrl^n 895 "TOd^^BISiT 12 conversation, but, again, this is your deposition, and this is what is going to be on the record. So, to the best of your recollection, was this all a part of that same initial conversation? A I think you are correct, I think it was in the second telephone conversation we had about it, because it was also during that period of time he offered that one of my f agents could go down and see the aircraft, and that's where we got into him detailing to me where the aircraft were located. Q If we can step back to the first conversation, did he tell you that the planes were b-?ing used to carry medical and humanitarian supplies? A That is what he indicated to me. Q Did he mention who actually purchased the aircraft? A No, I don't recall him mentioning that, no. Q If we can explain the term, "Maule", is that the name of a company or the neune of an aircraft? A That's the name of a company. Q What does the company do, to your knowledge? A Manufactures and builds aircraft, assembles air- craft. Q Maule was not the purchaser of the aircraft, it sold it to someone else? A That is correct. Um&££[i:tfA T 896 14 l]NI!fii$Slfl!F
13
1 Q Colonel North did not give you the name of the
2 individuals or corporations that purchased the aircraft?
3 A No. I didn't think he would know that information,
that is why I was asking for the purchase orders, the invoices,
5 the documentation associated with a sale, particularly this
6 sale of four aircraft.
7 Q In any of your conversations with Colonel North, did
8 he ever mention Richard Secord was involved with this air-
g craft?
10 A Not that I recall.
•J1 Q Do you want to go off the record?
12 A Yes.
13 (Discussion off the record.)
BY MS. NAUGHTON:
15 Q If we can go on the record.
^g Would you answer that question and tell me what you
said off the record?
A To the best of my recollection. Colonel North did
not mention Mr. Secord 's name at that time. However, later
on, when I acquired some records from Colonel North, I
happened to have observed the name, Secord, on one of the
documents provided to me.
Q And did he provide you the documents sometime in
November of 1986?
A Yes. My best recollection of that would have been
IJIJIU ikCCiClCftn
nfflD UJlMrlKITr
897
wmwip'
November 17, the morning of November 17, they were picked up
by my Enforcement Assistant at my direction after I had a
telephone conversation with Colonel North.
Q Could you explain to me when -- at the time that
you first made the phone call to Colonel North, what did you
understand his job to be at tl.<i NSC? Who did you understand
that he was?
A That he was a — my impression was he was a high-
ranking official within the National Security Council.
Q Did you know what it is he did there?
No.
No.
Do you know what his — did he explain to you what
his involvement was at all in this whole issue of this air-
craft?
A No. But that's not unusual for me to get calls or
even a Commissioner to get calls in our capacity, nor was
it unusual for me when 1 was working in the field as a
special agent in charge to get a call from different indi-
viduals. Sometimes they were businessmen, sometimes they
were congressional staffers, making inquiry about a case or
making representations about individuals or corporations.
It's not the first time I have heard the term
"good guys" by people that would call up and make an inquiry
Tnilii MtMUtir
82-732 O-88-30
wsmm
15
' about an investigation being conducted by special agents of
2 U.S. Customs.
3 Q Did Colonel North tell you how he learned this
^ information?
5 A No. However, let me qualify my answer. During the
6 course of tuat initial conversation and the subsequent con-
7 versation, it beccune obvious to me that somebody in Maule
8 had communicated either directly with Colonel North or through
9 an intermediary. Otherwise how would he know our people were
10 conducting an investigation?
11 Q Did you discuss any other case with Colonel North
12 on that initial conversation?
13 A No,
14 Q We will discuss later on what I will refer to as
15 the Kelso case.
16 Did you discuss that with Colonel North during that
17 initial conversation?
18 A Not at that time, no.
19 Q At that point, that first conversation, had a grand
20 jury subpoena actually been served to Maule?
21 A No.
22 Q Did you and Colonel North discuss the service of
23 such a subpoena?
24 A No.
25 Q After speaking with North, what did you do?
MMin HjiawVAIill 1 1
899
INRIOTSBr
16
A Subsequent to speaking with Colonel North, I called
Mr. Leon Guinn, who is the Assistant Commissioner for En-
forcement, Southeast Region, inquired about the case, the
Maule investigation specifically, asked him what the status
was. He informed me that Maule Aviation officials had been
uncooperative in the course of our investigation and that the
special agent and the special agent in charge were discussing
with the Assistant U.S. Attorney assigned to the case, or
at least the Assistant U.S. Attorney, and our people were
10 discussing the matter about going for a grand jury subpoena.
11 I indicated to Leon that I had a i»rce whereby I
12 thought I could expedite the investigation and make a
13 preliminary determination whether we had a violation or did
14 not have a violation and how much more we should pursue this
15 matter. I would like to pause here in my deposition to
16 point out to you, we have gotten — we, the U.S. Customs
17 Service -- has gotten a lot of allegations about various
18 materials being sent to the contras. Principally, we got
19 these leads from the Federal Bureau of Investigation, and
20 invariably when we pursued them, the allegations were either
21 unfounded or it was difficult, if not impossible, to pursue
22 them, because you would have to go into Nicaragua. Our agents
23 were just not allowed into Nicaragua.
24 So I indicated to Mr. Guinn, if he had no objections
25 I would like to utilize this source and see if we can get
imryjiocicicn
VnilLnodnflinir
900
25
ONttKSSIPIlii'
17
1 these documents to make a determination of whether to pursue
2 it and how intense we should pursue it.
3 Q Did you tell Mr. Guinn who your source was?
4 A No, I did not.
5 Q Any reason why not?
6 A I didn't think he needed to know.
7 Q Did Guinn, in effect, tell you that Maule Aircraft
8 was stonewalling the investigation and not being cooperative?
9 A Yes. I have already indicated that. That's the
10 term I used during our interval. I think I basically said the
11 seime thing, they were being very uncooperative.
12 Q When is the next time that you communicated with
13 Colonel North regarding this investigation?
^4 A I would say a couple weeks after my initial tele-
^Q documents or any call from him, so I pursued the matter by
17 calling him —
1g Q If I can stop you there for one second, did you
19 ever send any written materials to Colonel North, any notes,
2Q any letters, anything of that type?
21 A NO.
22 Q Other than the documents provided to you on this
23 investigation, did he send to you any memoranda, letters.
24 notes, any documents?
A No. We are jumping ahead now. Other than what
iiM^ni MnTwfi ■vrwTi
901
Mmm^
we have discussed at our initial interview.
Q That he delivered on November 14?
A Well, he or — what is his name — Owens
delivered. I don't want to jump ahead. You have to guide
this thing.
Q Did you make any contemporaneous notes during any
of your conversations with Colonel North?
A No.
Q Did you make any notes afterwards or any memoranda
of your conversations with Colonel North?
A No.
Q Did you keep any logs which would indicate when you
spoke to Colonel North?
A The only thing that I kept was the telephone number
for Colonel North's office and also the telephone number for
Mr. Owens and the name of the firm, if you will, or the name
that Mr. Owens gave to me for his particular position there
too.
Q You said approximately two weeks later you called
North to ask him where the documents and photographs were.
What did he tell you about them?
A That he was still trying to obtain them from Maule.
This is when he offered to have me send an agent down^^^^^H
because that was one of the require-
ments I wanted with respect to our initial conversation on it,
902
''VpL/IWnTHr
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
because this would
a gil^ejus a good idea whether or not it
had a STOL kit, also whether or not it had hard points. He
was a little apologetic he had not gotten the documents to
me during the intervening two weeks. I reiterated that the
sooner we got the documents, the sooner we would be able to
make a determination. And if he could get the documents, then
we would be proceeding with our investigation.
Q Had Colonel North told you that all of the planes
A I am not positive, but I recollect that there was a
reference to]
Q And he told you one had crashed, but he was not
sure where, is that correct?
A Yes, I am not sure where it crashed other than he
stated it had crashed, it was ^^^^^^^^^H Based on what
one would assume, without asking a follow-up question, that
it had crashed ^^^^^^H^^H Technically, from the way
you are asking me the question, it could have crashed any
place, and someone could have ferried it over and put it in
Q As far as you understood, the remnants of the
airplane —
A Yes, the remnants of the airplane were)
IIVIIUI 0IIMHJLIII
VNSU^IRiSr
A He used the term "crashed" with me, okay?
Q And the remaining three were
A
Q Did he mention to you how it crashed?
A No.
Q Did he offer to arrange for your agents to view
the aircraft in Central America?
A Yes. And I asked him whether this had to be done
openly or otherwise, and he said, no, it could not be
openly, and I said, well, we can't get involved in that,
and I just courteously asked him to get the documents and
photographs I had requested in my initial conversation with
him to me as quickly as possible.
Q Did he explain to you why your agents would not be
able to go down there overtly and check into the embassy and
do things according to regular procedure?
A No. And I didn't ask him.
Q Did you find this to be suspicious?
A It is an interesting phenomena. There is times
when various agencies that are stationed in foreign countries
will say, "Gee, we have no problem", and sometimes the
embassy will say, "No, we don't want you down" or vice-versa,
the embassy has no problem but the agency may have a problem
with us coming down, and we have to work all these things
out.
ilAlCIAJUMOn
904
24
oNuLmJainni
21
1 I didn't find it unusual that he wouldn't explain
2 it. You have got to remember that I am — I ,was somewhat
3 conversant with current events about^^^^^^^^^Bthe
4 Nicaraguan matter, and if he said that he had — my agent
5 would have to go down ^^^^^H^^H not in the official
6 capcwity as an agent, I assumed there had to be a reason
7 that he was knowledgeable about, and since he was with the
8 NSC, I had to respect that.
9 Q Did Colonel North, after this conversation, which
10 is approximately two weeks after the first, and mid-Sep-
12 or was it always a matter of you checking back?
13 A As it relates to this investigation, it was always
14 me calling him.
■J5 Q And then after that second conversation, do you
15 recall if you called him again? This would be after mid-
•J7 September.
13 A Relating to this investigation?
19 Q Yes.
20 A Yes.
21 Q Do you recall approximately how many times?
22 A I would estimate, it had to be either three or
23 four times, I can't tell you exactly was it three or four.
but it was one of the two.
25 Q During this period xl time, were you also in contact
nnjiiBi_miiniuili 1 1
905
DNtOtSSIPilT
with the Southeast Region telling them what was going on, or
were they inquiring what they could do next, that sort of
thing?
A I would say approximately three to four weeks after
my initial telephone conversation with Mr. Guinn, we were
having a telephone conversation about other Customs matters,
and this issue came up. And as a result, I am confident
that it stimulated my making the third phone call, if you
will, and, once again, when I called Colonel North, he was
very apologetic this time that he had not gotten the material
to me, he told me once again he was going to get right on it.
And I would say that this had to be near the end of September
by this time.
There was subsequent conversation with Mr. Guinn in
a conference call, and this would have been in November, I
would say mid-November, whereby we had a conference call,
he and I, along with Clark Settles, who was a special agent
in charge in Charleston, and both of them were inquiring
about the investigation, and I said, gee, I am surprised that
you to continue the investigation, and I related to him at
that time that based upon the documents submitted by my
source and upon review of those documents, that they were
very shallow, they were not responsive to answer the questions
that needed to be answered to determine whether or not a
wiiuUiiiffi rililf 1 1
906
DNSmKftT
23
2 to our Strategic Division and that their case agent from
3 Atlanta had reviewed them, along with the Division Director
* in Strategic, and we all agree that they, they did not
5 address the issue, and they were going to continue to conduct
6 the investigation.
7 Q That was sometime in mid or late November?
8 A It was mid-November.
9 Q Now, between that time, then, from late September
10 until mid-November, did you continue to try to get the docu-
11 ments from Colonel North?
12 A Yes. Like I said, there had to be some time in
13 October, and I am not sure, probably middle of October, that
15 Q If I can freeze you in time for a moment of that,
16 let's say October of 1986. In October of 1986, if you had
17 been told the name Richard Secord, would that have run any
18 bells with you at all concerning other investigations?
19 A Yes, the name, Richard Secord, not only in con-
20 junction with the investigation, but it was a name appearing
21 in the paper, so I was feuniliar with the name, Richard
22 Secord.
23 Q When it was appearing in the paper, was that in
24 connection with possible contra supply programs?
25 A Yes.
innii.ffuiMiiijifP
907
VttOU^fflEfiT
24
Q Do you ever recall discussing the Maule investiga-
tion with Colonel North at the same time or in the same
conversation which you were discussing the Southern Air
Transport investigation? I know we are jumping ahead a
little bit.
A I am not absolutely positive of this, but I think
that at one time when I was discussing the Southern Air
Transport, I had mentioned to, or not only mentioned, but I
reiterated to Colonel North that I was still waiting for the
documentation on the Maule, and I wasn't as courteous as I
was in the previous conversations because I was getting very
exacerbated because we are talking six to eight weeks, and I
still don't have documentation. I was put out.
Q Now, in early November, I believe, you were
visited by an attorney from the Public Integrity Section of
the Department of Justice named Ralph Martin, who had been
assigned to review contra-related cases and review of the
House Judiciary Committee's inquiry to appoint Independent
Counsel to study the whole problem after the Hasenfus crash
in October of 1986. Do you recall that meeting?
A Yes.
A He asked — he had a letter that contained a, quite
a few names in a letter, and he asked me whether or not I was
familiar with some of those names, or any of those names.
■nrD ikVrtiiJiiii'
908
WitHiSaaElT
25
1 Q Okay. Now, who was the letter from?
2 A I think it was from Congressman or Senator Kerry
3 going over to the Attorney General.
4 Q Did that list of names include Richard Secord?
5 A It may have. I don't recall. I mean, for me to
6 look at that letter, with all the names on it, I don't keep
7 all these names in my head. That meeting, by the way, so we
8 get it on the record, it was not only Mr. Martin, but there
9 was another attorney there as well. There were people from
10 my office there specifically —
11 Q Excuse me, when you say another attorney, you mean
12 from the Department of Justice?
13 A Yes.
14 Q Was that Marshall Jarrett?
15 A It could have been. I just don't remember the
^5 n£une .
^7 From Customs, Rafael Lopez, who was our Branch
18 Chief for Munitions, as well as Gary W-a-u-g-h, who was our
19 Strategic Division Director — Branch Chief, rather. At the
20 time I asked Ray to make sure they go against all the names
21 against our files, and as I was out of town, I was going down
22 to the Southwest, as well as overseas as best I can recollect
23 now, 1 wanted to make sure that we were responsive to Mr.
24 Martin's inquiry and whether or not we had any active
25 investigations or any kind of inquiries or anything like that,
■tlllBLJIlUilTIHiJIP
909
inm^M^
26
I wanted that to be responsive.
In my absence, a memorandum was prepared by Mr.
Lopez, signed by Mr. Lopez, going over to Mr. Martin with
the result of our inquiry against our indices, whether or not
these names meant anything to us.
Q Aside from the names, did Mr. Martin inquire about
any ongoing investigations you had relating to the contras?
A Yes. And I believe again Mr. Lopez discussed with
him whatever investigations we may have had. I believe he
was talking about active investigations. And as I have
already stated in this deposition, there was a number of
allegations over the course of the last several years about
arms going down to the contras and arms going to the
Sandinistas that they were compelled to check out. In most
of the cases, I would say invariably they proved to be un-
founded.
Q Did you tell Mr. Martin anything about the Maule
Aircraft investigation?
A No, I did not.
Q Why not?
A Because Ray Lopez could just have easily have
Colonel North?
A No, he did not know about my communications with
Hm&SSiflFBT
910
eNRKSSffPT
27
1 Colonel North, but they were aware that I was dealing with
2 a source in hopes to get information; that had no bearing
3 on whether or not we told Martin whether or not we had an
4 investigation. It was no secret that we had an investiga-
5 tion, that was open and above board.
Q You didn't tell Mr. Martin about the Maule investi-
7 gation, is that correct? You left that to Mr. Lopez?
8 A I am not saying I did or didn't. I don't recall
g if I did or did not mention the Maule. I could well have.
•JO If I didn't, it wasn't because I was holding something back,
11 it was an open investigation on our inventory that would be
12 easily discernible if the Maule name came up or insofar as
would be something that would be known not only to me but
also to my Branch Chiefs and Division Directors.
Q In answer to my question, do you remember
17 specifically discussing the Maule investigation with Mr.
Martin?
A At this time, no, I do not remember, but I want to
maJce sure it is clear on the record that if the Maule
investigation had come up in the context of our conversation,
Mr. Martin would have been advised.
Q Would you have told Mr. Martin — well, that is
2- with Colonel North regarding this investigation?
911
DNIiEASSIHffiT
28
A No.
Q Regarding the Southern Air Transport investigation,
was that discussed with Mr. Martin at this meeting?
A It may have been, because -- if you could refresh
my memory with respect to the date you are talking about,
Mr. Martin came over to my office, it would be helpful.
Q I believe it is around November 2.
A If it is November 2, then I believe the SAT
happened around October 5, if I am not mistaken. So if they
were pursuing that, that — I cannot believe it would not
come up in our conversation, okay? And if it did, even if
it didn't, I would have indicated we were conducting an
investigation, which we were.
Q Do you recall whether or not you told Mr. Martin
SAT investigation?
A I don't recall, but in all likelihood, I probably
did not say anything about my conversation with Colonel North.
Q When you say you probably did not, on what would
you base that statement?
A I don't recall Colonel North's name ever coming up
in a conversation, in my conversation with Mr. Martin.
Q Mr. Martin did not bring it up?
A No.
Q You did not bring it up?
llfilN.NBu1llCtr
912
ONKimiirr
29
1 A No.
2 Q Was there any discussion with Mr. Martin regarding
3 the Kelso case?
4 A I don't recall. I don't believe so. I can't
5 believe that would come up, because I did not perceive that
Kelso case as a contra matter. Okay? If you want to get
into it, we can get into it, but it will be out of sequence.
To me, that's more of an informant situation, okay, vis-a-vis
9 allegations of counterfeit money and narcotics allegations
■JO relative to the Drug Enforcement Administration, and the
•)•) status of Kelso, subsequent to all that and him going to
12 this farm or ranch and going back to the United States, you
•J3 know, I happened to be in Costa Rica, but I don't see that
14 fitting into the Kerry inquiry.
Q When you received the documents from Colonel North
on November 14, is that the first —
A Go over that again. When I received the documents
from?
Q Colonel North.
A What date?
Q Fourteenth.
A The 17th I believe I said.
Q Did they indicate that Udall Corporation was in-
volved in the purchase of the aircraft?
A Within the documents I recall seeing the name.
onutiKMiirUwr
913
mmsm
1 Udall, on a piece of documentation. What that documentation
2 was, I do not recall at this late date.
3 Q Is that the first time that you were aware that
4 Udall was involved in the Maule Aircraft investigation?
5 A In the Maule Aircraft investigation, yes.
6 Q In other words, Colonel North did -ot tell you
8 A No, ma'am.
9 Q Now, the story regarding the Iranian arms sales
10 broke on or about November 3 or 4, 1986. I believe you told
11 us in your interview on or cibout November 10, you discussed
12 your concerns regarding Colonel North's activities with the
13 Commissioner, is that correct?
14 A That is correct.
15 Q Can you tell us why you discussed it and what you
1g discussed?
•J7 A That would bring us back to the telephone conversa-
18 tion that I had on or about October 29 or 30.
19 Q With whom?
20 A We are talking about SAT, are we not?
21 Q No. Let me rephrase my question. When you went
22 to speak to the Commissioner on November 10, were your
23 concerns centered around the SAT investigation or the Maule
24 Aircraft investigation?
25 A Primarily the SAT. And my conversation that I had
UiiifiUS&iHE&ai
914
KNftASSIPKST
31
1 with Colonel North on or about the evening of October 29 or
2 30.
3 Q Okay. Then let me — let's stay with Maule, and
5 A I don't want to mislead you, that doesn't mean I
didn't mention to the Comr.issioner abou# Maule.
Q Sure.
A That wasn't what drove me to meet with him and
discuss my conversations and dialogue with Colonel North.
10 Q I understand. You agreed with the Commissioner,
11 correct me if I am wrong, to meet with Mr. Kimmet and dis-
12 cuss the issues with him, is that correct?
13 A It is not a question of agreeing, this is what the
■J4 Commissioner advised me, told me to do. It is not a question
15 of agreeing.
■\Q Q Can you tell us who Mr. Kimmet is?
•J7 A He is the General Counsel, United States Treasury
1g Department.
ig Q Now, when was your scheduled meeting to be with
20 Mr, Kimmet?
21 A The 17th, around 3:00, 3:00, 3:30 in the afternoon.
22 Q Did you talk to Colonel North the morning of
November 17?
A Yes. I already indicated I did.
Q Regarding the Maule case, what, if anything, did
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1 he tell you?
2 A I initiated the phone call in an effort to obtain
3 the documents that I had requested back the end of August,
4 beginning of September on Maule, and I was, quite frankly,
5 surprised during that conversation that Colonel North said
6 he had ^he documents and that he was waiting to give me the
7 documents. I indicated to him that I had a pretty busy
8 schedule that day, and I would like to send over my Enforce-
9 ment Assistant to get a copy. He said, well, you could have
10 the original. I told him, no, I did not want the originals
11 of the documents, that I wanted the originals of the aocuments
12 to be given to the investigative agent by Maule and that I
would like to have a copy.
Arrangements were made between Colonel North and
myself to have my Enforcement Assistant go over and pick
up a sealed envelope which later turned out to be a copy of
documents — I presume a copy of documents, and as I said, I
reviewed them, and subsequent, not that same day, maybe that
evening or later, and then sent them up to my Strategic
Investigations Division with word I wanted the investigation
to resume.
documentation that Colonel North had provided?
A It did not clearly show what I would consider
iiMpi A pci nrn..
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1 purchase orders, and particularly destination of the air-
2 craft. There were no photographs included in the package,
3 which I believe were vital to determine whether or not a
5 Q Did the documents indicate who all of the purchasers
6 were? That is, there were four aircraft —
7 A I don't recall.
8 Q Now, when you discussed this with Colonel North on
9 the morning of November 17, did you tell him that you had
10 talked to the Commissioner?
11 A No.
12 Q Did you tell him that you were going to meet with
13 Kimmet?
14 A No.
15 Q Any reason why you didn't?
15 A I didn't think it was very prudent since — you
17 recall, in our earlier discussion, I indicated to you when
18 I talked to Colonel North on the evening of October 29 or 30,
19 when he was out of the country, that I asked him when he
20 came back that he and I and the Commissioner had to get
21 together. When I called on the 17th, it was obvious to me
22 he had been in town for some time and for some reason had
23 not contacted me or the Commissioner about getting together.
24 My main concern was that I wanted to see if I could
25 get the docviments that he had indicated that he would get to
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17
22
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34
1 me for the Maule investigation. Therefore, when I called
2 him on the morning of the 17th and I, in my conversation
3 with the Commissioner on the 10th of November, where he
4 directed me to meet with Mr. Kimraet to discuss this whole
5 matter and get some advice from him, it beccune clear to me
6 that some of my concerns may have been somewhat valid if the
7 Commissioner was asking me to go over and discuss the matter
8 with Mr. Kimmet. I may not have any subsequent conversation
9 with Colonel North from that point on, and I didn't feel I
11 this matter and how I was going to resolve my uneasiness and
12 concerns and my lack of getting this documentation I had been
13 promised six or eight weeks ago.
14 Q Do you know whether or not Colonel North intended
15 to call the Commissioner? Did he express any intent, or did
1g you suggest he do so at the end of that conversation?
A You mean the conversation of the 17th —
^g Q Of the 17th of November.
19 A No.
21 to which question? Did he express any intent to call the
Commissioner?
23 A No, he did not.
24 Q Did you suggest that?
25 A No, ito did not.
imA^lflPfiT
918
omwMWffT
35
1 Q Did you suggest he call the Commissioner?
2 A No. I did suggest — as I said, just to reiterate,
3 when I talked to him the evening of October 29 or 30, I
4 indicated to him let's get together.
5 Q You don't recall such a thing on November 17?
6 A No.
7 Q Was that the last conversation you had with Colonel
8 North?
9 A I believe it was. I was just trying to think psat
10 that date. I just don't recall ever having a conversation —
11 a face-to-face or telephone conversation with him since.
12 Q By the way, did you tell Colonel North about your
13 visit with Mr. Martin from the Department of Justice?
14 A Not that I recall.
15 Q Let's tie that up. After your conversation with
15 Colonel North on the 17th, and you reviewed the documents
17 that had been provided to you from him, what did you do
18 with regard to the Maule investigation from that point on?
19 A As I said, I forwarded those documents up to the
20 Director of the Strategic Investigations Division, indicating
21 that I did not believe that the documents were responsive or
22 worthwhile and that if he concurred, and that is when he
23 mentioned the case agent from Atlanta happened to be in, I
24 said, if you guys agree they are worthless, go conduct the
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https://www.science.gov/topicpages/c/coarse-graining+protein+energetics.html | #### Sample records for coarse-graining protein energetics
1. Coarse-Grain Modeling of Energetic Materials
Brennan, John
2015-06-01
Mechanical and thermal loading of energetic materials can incite responses over a wide range of spatial and temporal scales due to inherent nano- and microscale features. Many energy transfer processes within these materials are atomistically governed, yet the material response is manifested at the micro- and mesoscale. The existing state-of-the-art computational methods include continuum level approaches that rely on idealized field-based formulations that are empirically based. Our goal is to bridge the spatial and temporal modeling regimes while ensuring multiscale consistency. However, significant technical challenges exist, including that the multiscale methods linking the atomistic and microscales for molecular crystals are immature or nonexistent. To begin addressing these challenges, we have implemented a bottom-up approach for deriving microscale coarse-grain models directly from quantum mechanics-derived atomistic models. In this talk, a suite of computational tools is described for particle-based microscale simulations of the nonequilibrium response of energetic solids. Our approach builds upon recent advances both in generating coarse-grain models under high strains and in developing a variant of dissipative particle dynamics that includes chemical reactions.
2. COARSE-GRAINED MODELING OF PROTEIN UNFOLDING DYNAMICS*
PubMed Central
DENG, MINGGE
2014-01-01
We present a new dynamic elastic network model (DENM) that describes the unfolding process of a force-loaded protein. The protein interaction network and its potentials are constructed based on information of its native-state structure obtained from the Protein Data Bank, with network nodes positioned at the Cα coordinates of the protein backbone. Specifically, to mimic the unfolding process, i.e., to simulate the process of overcoming the local energy barrier on the free energy landscape with force loading, the noncovalent protein network bonds (i.e., hydrogen bonds, salt bridges, hydrophobic contacts, etc.) are broken one-by-one with a certain probability, while the strong covalent bonds along the backbone (i.e., peptide bonds, disulfide bonds, etc.) are kept intact. The jumping event from local energy minima (bonds breaking rate) are chosen according to Kramer’s theory and the Bell model. Moreover, we exploit the self-similar structure of proteins at different scales to design an effective coarse-graining procedure for DENM with optimal parameter selection. The robustness of DENM is validated by coarse-grained molecular dynamics (MD) simulation against atomistic MD simulation of force-extension processes of the Fibrinogen and Titin Immunoglobulin proteins. We observe that the native structure of the proteins determines the total unfolding dynamics (including large deviations) and not just the fluctuations around the native state. PMID:25400515
3. A coarse grain model for protein-surface interactions
Wei, Shuai; Knotts, Thomas A.
2013-09-01
The interaction of proteins with surfaces is important in numerous applications in many fields—such as biotechnology, proteomics, sensors, and medicine—but fundamental understanding of how protein stability and structure are affected by surfaces remains incomplete. Over the last several years, molecular simulation using coarse grain models has yielded significant insights, but the formalisms used to represent the surface interactions have been rudimentary. We present a new model for protein surface interactions that incorporates the chemical specificity of both the surface and the residues comprising the protein in the context of a one-bead-per-residue, coarse grain approach that maintains computational efficiency. The model is parameterized against experimental adsorption energies for multiple model peptides on different types of surfaces. The validity of the model is established by its ability to quantitatively and qualitatively predict the free energy of adsorption and structural changes for multiple biologically-relevant proteins on different surfaces. The validation, done with proteins not used in parameterization, shows that the model produces remarkable agreement between simulation and experiment.
4. Coarse-Grained Models for Protein-Cell Membrane Interactions
PubMed Central
2015-01-01
The physiological properties of biological soft matter are the product of collective interactions, which span many time and length scales. Recent computational modeling efforts have helped illuminate experiments that characterize the ways in which proteins modulate membrane physics. Linking these models across time and length scales in a multiscale model explains how atomistic information propagates to larger scales. This paper reviews continuum modeling and coarse-grained molecular dynamics methods, which connect atomistic simulations and single-molecule experiments with the observed microscopic or mesoscale properties of soft-matter systems essential to our understanding of cells, particularly those involved in sculpting and remodeling cell membranes. PMID:26613047
5. Recent advances in transferable coarse-grained modeling of proteins.
PubMed
Kar, Parimal; Feig, Michael
2014-01-01
Computer simulations are indispensable tools for studying the structure and dynamics of biological macromolecules. Biochemical processes occur on different scales of length and time. Atomistic simulations cannot cover the relevant spatiotemporal scales at which the cellular processes occur. To address this challenge, coarse-grained (CG) modeling of the biological systems is employed. Over the last few years, many CG models for proteins continue to be developed. However, many of them are not transferable with respect to different systems and different environments. In this review, we discuss those CG protein models that are transferable and that retain chemical specificity. We restrict ourselves to CG models of soluble proteins only. We also briefly review recent progress made in the multiscale hybrid all-atom/CG simulations of proteins.
6. Unconstrained Structure Formation in Coarse-Grained Protein Simulations
Bereau, Tristan
The ability of proteins to fold into well-defined structures forms the basis of a wide variety of biochemical functions in and out of the cell membrane. Many of these processes, however, operate at time- and length-scales that are currently unattainable by all-atom computer simulations. To cope with this difficulty, increasingly more accurate and sophisticated coarse-grained models are currently being developed. In the present thesis, we introduce a solvent-free coarse-grained model for proteins. Proteins are modeled by four beads per amino acid, providing enough backbone resolution to allow for accurate sampling of local conformations. It relies on simple interactions that emphasize structure, such as hydrogen bonds and hydrophobicity. Realistic alpha/beta content is achieved by including an effective nearest-neighbor dipolar interaction. Parameters are tuned to reproduce both local conformations and tertiary structures. By studying both helical and extended conformations we make sure the force field is not biased towards any particular secondary structure. Without any further adjustments or bias a realistic oligopeptide aggregation scenario is observed. The model is subsequently applied to various biophysical problems: (i) kinetics of folding of two model peptides, (ii) large-scale amyloid-beta oligomerization, and (iii) protein folding cooperativity. The last topic---defined by the nature of the finite-size thermodynamic transition exhibited upon folding---was investigated from a microcanonical perspective: the accurate evaluation of the density of states can unambiguously characterize the nature of the transition, unlike its corresponding canonical analysis. Extending the results of lattice simulations and theoretical models, we find that it is the interplay between secondary structure and the loss of non-native tertiary contacts which determines the nature of the transition. Finally, we combine the peptide model with a high-resolution, solvent-free, lipid
7. Interactions of membranes with coarse-grain proteins: a comparison
Neder, Jörg; Nielaba, Peter; West, Beate; Schmid, Friederike
2012-12-01
We study the interactions between lipid bilayers and rigid transmembrane proteins by Monte Carlo simulations of generic coarse-grain models. Different popular protein models are considered and compared with each other, and key parameters such as the hydrophobicity and the hydrophobic mismatch are varied systematically. Furthermore, the properties of the membrane are manipulated by applying different tensions. The response of the membrane to the insertion of single proteins is found to be mostly generic and independent of the choice of the protein model. Likewise, the orientational distributions of single proteins depend mainly on the hydrophobic mismatch and the hydrophobicity of the proteins, and are otherwise similar for all protein models. Orientational distributions are generally found to be very broad, i.e. tilt angles fluctuate very much, in agreement with experimental findings. Weakly hydrophobic proteins respond to positive hydrophobic mismatch by tilting. Strongly hydrophobic (strongly bound) proteins distort the surrounding membrane and tend to remain upright. For proteins with intermediate hydrophobicity, the two mechanisms compete, and as a result, the tilt only sets in if the hydrophobic mismatch exceeds a threshold. Clusters of several strongly hydrophobic proteins with negative positive mismatch may nucleate raft-like structures in membranes. This effect is more pronounced for proteins with rough, structured surfaces.
8. Refining the treatment of membrane proteins by coarse-grained models.
PubMed
Vorobyov, Igor; Kim, Ilsoo; Chu, Zhen T; Warshel, Arieh
2016-01-01
Obtaining a quantitative description of the membrane proteins stability is crucial for understanding many biological processes. However the advance in this direction has remained a major challenge for both experimental studies and molecular modeling. One of the possible directions is the use of coarse-grained models but such models must be carefully calibrated and validated. Here we use a recent progress in benchmark studies on the energetics of amino acid residue and peptide membrane insertion and membrane protein stability in refining our previously developed coarse-grained model (Vicatos et al., Proteins 2014;82:1168). Our refined model parameters were fitted and/or tested to reproduce water/membrane partitioning energetics of amino acid side chains and a couple of model peptides. This new model provides a reasonable agreement with experiment for absolute folding free energies of several β-barrel membrane proteins as well as effects of point mutations on a relative stability for one of those proteins, OmpLA. The consideration and ranking of different rotameric states for a mutated residue was found to be essential to achieve satisfactory agreement with the reference data.
9. PRIMO: A Transferable Coarse-grained Force Field for Proteins.
PubMed
Kar, Parimal; Gopal, Srinivasa Murthy; Cheng, Yi-Ming; Predeus, Alexander; Feig, Michael
2013-08-13
We describe here the PRIMO (PRotein Intermediate Model) force field, a physics-based fully transferable additive coarse-grained potential energy function that is compatible with an all-atom force field for multi-scale simulations. The energy function consists of standard molecular dynamics energy terms plus a hydrogen-bonding potential term and is mainly parameterized based on the CHARMM22/CMAP force field in a bottom-up fashion. The solvent is treated implicitly via the generalized Born model. The bonded interactions are either harmonic or distance-based spline interpolated potentials. These potentials are defined on the basis of all-atom molecular dynamics (MD) simulations of dipeptides with the CHARMM22/CMAP force field. The non-bonded parameters are tuned by matching conformational free energies of diverse set of conformations with that of CHARMM all-atom results. PRIMO is designed to provide a correct description of conformational distribution of the backbone (ϕ/ψ) and side chains (χ1) for all amino acids with a CMAP correction term. The CMAP potential in PRIMO is optimized based on the new CHARMM C36 CMAP. The resulting optimized force field has been applied in MD simulations of several proteins of 36-155 amino acids and shown that the root-mean-squared-deviation of the average structure from the corresponding crystallographic structure varies between 1.80 and 4.03 Å. PRIMO is shown to fold several small peptides to their native-like structures from extended conformations. These results suggest the applicability of the PRIMO force field in the study of protein structures in aqueous solution, structure predictions as well as ab initio folding of small peptides.
10. Microcanonical thermostatistics of coarse-grained proteins with amyloidogenic propensity
Frigori, Rafael B.; Rizzi, Leandro G.; Alves, Nelson A.
2013-01-01
The formation of fibrillar aggregates seems to be a common characteristic of polypeptide chains, although the observation of these aggregates may depend on appropriate experimental conditions. Partially folded intermediates seem to have an important role in the generation of protein aggregates, and a mechanism for this fibril formation considers that these intermediates also correspond to metastable states with respect to the fibrillar ones. Here, using a coarse-grained (CG) off-lattice model, we carry out a comparative analysis of the thermodynamic aspects characterizing the folding transition with respect to the propensity for aggregation of four different systems: two isoforms of the amyloid β-protein, the Src SH3 domain, and the human prion proteins (hPrP). Microcanonical analysis of the data obtained from replica exchange method is conducted to evaluate the free-energy barrier and latent heat in these models. The simulations of the amyloid β isoforms and Src SH3 domain indicated that the folding process described by this CG model is related to a negative specific heat, a phenomenon that can only be verified in the microcanonical ensemble in first-order phase transitions. The CG simulation of the hPrP heteropolymer yielded a continuous folding transition. The absence of a free-energy barrier and latent heat favors the presence of partially unfolded conformations, and in this context, this thermodynamic aspect could explain the reason why the hPrP heteropolymer is more aggregation-prone than the other heteropolymers considered in this study. We introduced the hydrophobic radius of gyration as an order parameter and found that it can be used to obtain reliable information about the hydrophobic packing and the transition temperatures in the folding process.
11. Coarse Grained Molecular Dynamics Simulations of Transmembrane Protein-Lipid Systems
PubMed Central
Spijker, Peter; van Hoof, Bram; Debertrand, Michel; Markvoort, Albert J.; Vaidehi, Nagarajan; Hilbers, Peter A.J.
2010-01-01
Many biological cellular processes occur at the micro- or millisecond time scale. With traditional all-atom molecular modeling techniques it is difficult to investigate the dynamics of long time scales or large systems, such as protein aggregation or activation. Coarse graining (CG) can be used to reduce the number of degrees of freedom in such a system, and reduce the computational complexity. In this paper the first version of a coarse grained model for transmembrane proteins is presented. This model differs from other coarse grained protein models due to the introduction of a novel angle potential as well as a hydrogen bonding potential. These new potentials are used to stabilize the backbone. The model has been validated by investigating the adaptation of the hydrophobic mismatch induced by the insertion of WALP-peptides into a lipid membrane, showing that the first step in the adaptation is an increase in the membrane thickness, followed by a tilting of the peptide. PMID:20640160
12. A coarse-grained protein-protein potential derived from an all-atom force field.
PubMed
Basdevant, Nathalie; Borgis, Daniel; Ha-Duong, Tap
2007-08-01
In order to study protein-protein nonbonded interactions, we present the development of a new reduced protein model that represents each amino acid residue with one to three coarse grains, whose physical properties are derived in a consistent bottom-up procedure from the higher-resolution all-atom AMBER force field. The resulting potential energy function is pairwise additive and includes distinct van-der-Waals and Coulombic terms. The van-der-Waals effective interactions are deduced from preliminary molecular dynamics simulations of all possible amino acid homodimers. They are best represented by a soft 1/r6 repulsion and a Gaussian attraction, with parameters obeying Lorentz-Berthelot mixing rules. For the Coulombic interaction, coarse grain charges are optimized for each separate protein in order to best represent the all-atom electrostatic potential outside the protein core. This approach leaves the possibility of using any implicit solvent model to describe solvation effects and electrostatic screening. The coarse-grained force field is tested carefully for a small homodimeric complex, the magainin. It is shown to reproduce satisfactorily the specificity of the all-atom underlying potential, in particular within a PB/SA solvation model. The coarse-grained potential is applied to the redocking prediction of three different protein-protein complexes: the magainin dimer, the barnase-barstar, and the trypsin-BPTI complexes. It is shown to provide per se an efficient and discriminating scoring energy function for the protein-protein docking problem that remains pertinent at both the global and refinement stage. PMID:17616119
13. A coarse-grained protein-protein potential derived from an all-atom force field.
PubMed
Basdevant, Nathalie; Borgis, Daniel; Ha-Duong, Tap
2007-08-01
In order to study protein-protein nonbonded interactions, we present the development of a new reduced protein model that represents each amino acid residue with one to three coarse grains, whose physical properties are derived in a consistent bottom-up procedure from the higher-resolution all-atom AMBER force field. The resulting potential energy function is pairwise additive and includes distinct van-der-Waals and Coulombic terms. The van-der-Waals effective interactions are deduced from preliminary molecular dynamics simulations of all possible amino acid homodimers. They are best represented by a soft 1/r6 repulsion and a Gaussian attraction, with parameters obeying Lorentz-Berthelot mixing rules. For the Coulombic interaction, coarse grain charges are optimized for each separate protein in order to best represent the all-atom electrostatic potential outside the protein core. This approach leaves the possibility of using any implicit solvent model to describe solvation effects and electrostatic screening. The coarse-grained force field is tested carefully for a small homodimeric complex, the magainin. It is shown to reproduce satisfactorily the specificity of the all-atom underlying potential, in particular within a PB/SA solvation model. The coarse-grained potential is applied to the redocking prediction of three different protein-protein complexes: the magainin dimer, the barnase-barstar, and the trypsin-BPTI complexes. It is shown to provide per se an efficient and discriminating scoring energy function for the protein-protein docking problem that remains pertinent at both the global and refinement stage.
14. Coarse-grained representation of protein flexibility. Foundations, successes, and shortcomings.
PubMed
Orozco, Modesto; Orellana, Laura; Hospital, Adam; Naganathan, Athi N; Emperador, Agustí; Carrillo, Oliver; Gelpí, J L
2011-01-01
Flexibility is the key magnitude to understand the variety of functions of proteins. Unfortunately, its experimental study is quite difficult, and in fact, most experimental procedures are designed to reduce flexibility and allow a better definition of the structure. Theoretical approaches have become then the alternative but face serious timescale problems, since many biologically relevant deformation movements happen in a timescale that is far beyond the possibility of current atomistic models. In this complex scenario, coarse-grained simulation methods have emerged as a powerful and inexpensive alternative. Along this chapter, we will review these coarse-grained methods, and explain their physical foundations and their range of applicability. PMID:21920324
15. Simulation of Coarse-Grained Protein-Protein Interactions with Graphics Processing Units.
PubMed
Tunbridge, Ian; Best, Robert B; Gain, James; Kuttel, Michelle M
2010-11-01
We report a hybrid parallel central and graphics processing units (CPU-GPU) implementation of a coarse-grained model for replica exchange Monte Carlo (REMC) simulations of protein assemblies. We describe the design, optimization, validation, and benchmarking of our algorithms, particularly the parallelization strategy, which is specific to the requirements of GPU hardware. Performance evaluation of our hybrid implementation shows scaled speedup as compared to a single-core CPU; reference simulations of small 100 residue proteins have a modest speedup of 4, while large simulations with thousands of residues are up to 1400 times faster. Importantly, the combination of coarse-grained models with highly parallel GPU hardware vastly increases the length- and time-scales accessible for protein simulation, making it possible to simulate much larger systems of interacting proteins than have previously been attempted. As a first step toward the simulation of the assembly of an entire viral capsid, we have demonstrated that the chosen coarse-grained model, together with REMC sampling, is capable of identifying the correctly bound structure, for a pair of fragments from the human hepatitis B virus capsid. Our parallel solution can easily be generalized to other interaction functions and other types of macromolecules and has implications for the parallelization of similar N-body problems that require random access lookups. PMID:26617104
16. Folding of small knotted proteins: Insights from a mean field coarse-grained model
SciTech Connect
Najafi, Saeed; Potestio, Raffaello
2015-12-28
A small but relevant number of proteins whose native structure is known features nontrivial topology, i.e., they are knotted. Understanding the process of folding from a swollen unknotted state to the biologically relevant native conformation is, for these proteins, particularly difficult, due to their rate-limiting topological entanglement. To shed some light into this conundrum, we introduced a structure-based coarse-grained model of the protein, where the information about the folded conformation is encoded in bonded angular interactions only, which do not favor the formation of native contacts. A stochastic search scheme in parameter space is employed to identify a set of interactions that maximizes the probability to attain the knotted state. The optimal knotting pathways of the two smallest knotted proteins, obtained through this approach, are consistent with the results derived by means of coarse-grained as well as full atomistic simulations.
17. A Generic Force Field for Protein Coarse-Grained Molecular Dynamics Simulation
PubMed Central
Gu, Junfeng; Bai, Fang; Li, Honglin; Wang, Xicheng
2012-01-01
Coarse-grained (CG) force fields have become promising tools for studies of protein behavior, but the balance of speed and accuracy is still a challenge in the research of protein coarse graining methodology. In this work, 20 CG beads have been designed based on the structures of amino acid residues, with which an amino acid can be represented by one or two beads, and a CG solvent model with five water molecules was adopted to ensure the consistence with the protein CG beads. The internal interactions in protein were classified according to the types of the interacting CG beads, and adequate potential functions were chosen and systematically parameterized to fit the energy distributions. The proposed CG force field has been tested on eight proteins, and each protein was simulated for 1000 ns. Even without any extra structure knowledge of the simulated proteins, the Cα root mean square deviations (RMSDs) with respect to their experimental structures are close to those of relatively short time all atom molecular dynamics simulations. However, our coarse grained force field will require further refinement to improve agreement with and persistence of native-like structures. In addition, the root mean square fluctuations (RMSFs) relative to the average structures derived from the simulations show that the conformational fluctuations of the proteins can be sampled. PMID:23203075
18. Coarse grained simulation reveals antifreeze properties of hyperactive antifreeze protein from Antarctic bacterium Colwellia sp.
Nguyen, Hung; Van, Thanh Dac; Le, Ly
2015-10-01
The novel hyperactive antifreeze protein (AFP) of Antarctic sea ice bacterium Colwellia sp. provides a target for studying the protection of psychrophilic microgoranisms against freezing environment. Interestingly, the Colwellia sp. hyperactive antifreeze protein (ColAFP) was crystallized without the structural dynamic characteristics. Here, the result indicated, through coarse grained simulation of ColAFP under various subfreezing temperature, that ColAFP remains active at temperature of equal and greater than 275 K (∼2 °C). Extensive simulation analyses also revealed the adaptive mechanism of ColAFP in subfreezing environment. Our result provides a structural dynamic understanding of the ColAFP.
19. Coarse-grained molecular dynamics simulations of protein-ligand binding.
PubMed
Negami, Tatsuki; Shimizu, Kentaro; Terada, Tohru
2014-09-30
Coarse-grained molecular dynamics (CGMD) simulations with the MARTINI force field were performed to reproduce the protein-ligand binding processes. We chose two protein-ligand systems, the levansucrase-sugar (glucose or sucrose), and LinB-1,2-dichloroethane systems, as target systems that differ in terms of the size and shape of the ligand-binding pocket and the physicochemical properties of the pocket and the ligand. Spatial distributions of the Coarse-grained (CG) ligand molecules revealed potential ligand-binding sites on the protein surfaces other than the real ligand-binding sites. The ligands bound most strongly to the real ligand-binding sites. The binding and unbinding rate constants obtained from the CGMD simulation of the levansucrase-sucrose system were approximately 10 times greater than the experimental values; this is mainly due to faster diffusion of the CG ligand in the CG water model. We could obtain dissociation constants close to the experimental values for both systems. Analysis of the ligand fluxes demonstrated that the CG ligand molecules entered the ligand-binding pockets through specific pathways. The ligands tended to move through grooves on the protein surface. Thus, the CGMD simulations produced reasonable results for the two different systems overall and are useful for studying the protein-ligand binding processes.
20. Distributions of experimental protein structures on coarse-grained free energy landscapes
Sankar, Kannan; Liu, Jie; Wang, Yuan; Jernigan, Robert L.
2015-12-01
Predicting conformational changes of proteins is needed in order to fully comprehend functional mechanisms. With the large number of available structures in sets of related proteins, it is now possible to directly visualize the clusters of conformations and their conformational transitions through the use of principal component analysis. The most striking observation about the distributions of the structures along the principal components is their highly non-uniform distributions. In this work, we use principal component analysis of experimental structures of 50 diverse proteins to extract the most important directions of their motions, sample structures along these directions, and estimate their free energy landscapes by combining knowledge-based potentials and entropy computed from elastic network models. When these resulting motions are visualized upon their coarse-grained free energy landscapes, the basis for conformational pathways becomes readily apparent. Using three well-studied proteins, T4 lysozyme, serum albumin, and sarco-endoplasmic reticular Ca2+ adenosine triphosphatase (SERCA), as examples, we show that such free energy landscapes of conformational changes provide meaningful insights into the functional dynamics and suggest transition pathways between different conformational states. As a further example, we also show that Monte Carlo simulations on the coarse-grained landscape of HIV-1 protease can directly yield pathways for force-driven conformational changes.
1. Membrane-Protein Interactions in a Generic Coarse-Grained Model for Lipid Bilayers
PubMed Central
West, Beate; Brown, Frank L.H.; Schmid, Friederike
2009-01-01
Abstract We study membrane-protein interactions and membrane-mediated protein-protein interactions by Monte Carlo simulations of a generic coarse-grained model for lipid bilayers with cylindrical hydrophobic inclusions. The strength of the hydrophobic force and the hydrophobic thickness of the proteins are systematically varied. The results are compared with analytical predictions of two popular analytical theories: The Landau-de Gennes theory and the elastic theory. The elastic theory provides an excellent description of the fluctuation spectra of pure membranes and successfully reproduces the deformation profiles of membranes around single proteins. However, its prediction for the potential of mean force between proteins is not compatible with the simulation data for large distances. The simulations show that the lipid-mediated interactions are governed by five competing factors: direct interactions; lipid-induced depletion interactions; lipid bridging; lipid packing; and a smooth long-range contribution. The mechanisms leading to hydrophobic mismatch interactions are critically analyzed. PMID:18835907
2. A polarizable coarse-grained protein model for dissipative particle dynamics.
PubMed
Peter, Emanuel K; Lykov, Kirill; Pivkin, Igor V
2015-10-01
We present a new coarse-grained polarizable protein model for dissipative particle dynamics (DPD) method. This method allows large timesteps in particle-based systems and speeds up sampling by many orders of magnitude. Our new model is based on the electrostatic polarization of the protein backbone and a detailed representation of the sidechains in combination with a polarizable water model. We define our model parameters using the experimental structures of two proteins, TrpZip2 and TrpCage. Backmapping and subsequent short replica-exchange molecular dynamics runs verify our approach and show convergence to the experimental structures on the atomistic level. We validate our model on five different proteins: GB1, the WW-domain, the B-domain of Protein A, the peripheral binding subunit and villin headpiece. PMID:26339692
3. Design of a rotamer library for coarse-grained models in protein-folding simulations.
PubMed
Larriva, María; Rey, Antonio
2014-01-27
Rotamer libraries usually contain geometric information to trace an amino acid side chain, atom by atom, onto a protein backbone. These libraries have been widely used in protein design, structure refinement and prediction, homology modeling, and X-ray and NMR structure validation. However, they usually present too much information and are not always fully compatible with the coarse-grained models of the protein geometry that are frequently used to tackle the protein-folding problem through molecular simulation. In this work, we introduce a new backbone-dependent rotamer library for side chains compatible with low-resolution models in polypeptide chains. We have dispensed with an atomic description of proteins, representing each amino acid side chain by its geometric center (or centroid). The resulting rotamers have been estimated from a statistical analysis of a large structural database consisting of high-resolution X-ray protein structures. As additional information, each rotamer includes the frequency with which it has been found during the statistical analysis. More importantly, the library has been designed with a careful control to ensure that the vast majority of side chains in protein structures (at least 95% of residues) are properly represented. We have tested our library using an independent set of proteins, and our results support a good correlation between the reconstructed centroids from our rotamer library and those in the experimental structures. This new library can serve to improve the definition of side chain centroids in coarse-grained models, avoiding at the same time an excessive additional complexity in a geometric model for the polypeptide chain.
4. CAMELOT: A machine learning approach for coarse-grained simulations of aggregation of block-copolymeric protein sequences
SciTech Connect
Ruff, Kiersten M.; Harmon, Tyler S.; Pappu, Rohit V.
2015-12-28
We report the development and deployment of a coarse-graining method that is well suited for computer simulations of aggregation and phase separation of protein sequences with block-copolymeric architectures. Our algorithm, named CAMELOT for Coarse-grained simulations Aided by MachinE Learning Optimization and Training, leverages information from converged all atom simulations that is used to determine a suitable resolution and parameterize the coarse-grained model. To parameterize a system-specific coarse-grained model, we use a combination of Boltzmann inversion, non-linear regression, and a Gaussian process Bayesian optimization approach. The accuracy of the coarse-grained model is demonstrated through direct comparisons to results from all atom simulations. We demonstrate the utility of our coarse-graining approach using the block-copolymeric sequence from the exon 1 encoded sequence of the huntingtin protein. This sequence comprises of 17 residues from the N-terminal end of huntingtin (N17) followed by a polyglutamine (polyQ) tract. Simulations based on the CAMELOT approach are used to show that the adsorption and unfolding of the wild type N17 and its sequence variants on the surface of polyQ tracts engender a patchy colloid like architecture that promotes the formation of linear aggregates. These results provide a plausible explanation for experimental observations, which show that N17 accelerates the formation of linear aggregates in block-copolymeric N17-polyQ sequences. The CAMELOT approach is versatile and is generalizable for simulating the aggregation and phase behavior of a range of block-copolymeric protein sequences.
5. CAMELOT: A machine learning approach for coarse-grained simulations of aggregation of block-copolymeric protein sequences
Ruff, Kiersten M.; Harmon, Tyler S.; Pappu, Rohit V.
2015-12-01
We report the development and deployment of a coarse-graining method that is well suited for computer simulations of aggregation and phase separation of protein sequences with block-copolymeric architectures. Our algorithm, named CAMELOT for Coarse-grained simulations Aided by MachinE Learning Optimization and Training, leverages information from converged all atom simulations that is used to determine a suitable resolution and parameterize the coarse-grained model. To parameterize a system-specific coarse-grained model, we use a combination of Boltzmann inversion, non-linear regression, and a Gaussian process Bayesian optimization approach. The accuracy of the coarse-grained model is demonstrated through direct comparisons to results from all atom simulations. We demonstrate the utility of our coarse-graining approach using the block-copolymeric sequence from the exon 1 encoded sequence of the huntingtin protein. This sequence comprises of 17 residues from the N-terminal end of huntingtin (N17) followed by a polyglutamine (polyQ) tract. Simulations based on the CAMELOT approach are used to show that the adsorption and unfolding of the wild type N17 and its sequence variants on the surface of polyQ tracts engender a patchy colloid like architecture that promotes the formation of linear aggregates. These results provide a plausible explanation for experimental observations, which show that N17 accelerates the formation of linear aggregates in block-copolymeric N17-polyQ sequences. The CAMELOT approach is versatile and is generalizable for simulating the aggregation and phase behavior of a range of block-copolymeric protein sequences.
6. A coarse-grained α-carbon protein model with anisotropic hydrogen-bonding
PubMed Central
Yap, Eng-Hui; Fawzi, Nicolas Lux; Head-Gordon, Teresa
2012-01-01
We develop a sequence based α-carbon model to incorporate a mean field estimate of the orientation dependence of the polypeptide chain that gives rise to specific hydrogen bond pairing to stabilize α-helices and β-sheets. We illustrate the success of the new protein model in capturing thermodynamic measures and folding mechanism of proteins L and G. Compared to our previous coarse-grained model, the new model shows greater folding cooperativity and improvements in designability of protein sequences, as well as predicting correct trends for kinetic rates and mechanism for proteins L and G. We believe the model is broadly applicable to other protein folding and protein–protein co-assembly processes, and does not require experimental input beyond the topology description of the native state. Even without tertiary topology information, it can also serve as a mid-resolution protein model for more exhaustive conformational search strategies that can bridge back down to atomic descriptions of the polypeptide chain. PMID:17879350
7. THE OPEP COARSE-GRAINED PROTEIN MODEL: FROM SINGLE MOLECULES, AMYLOID FORMATION, ROLE OF MACROMOLECULAR CROWDING AND HYDRODYNAMICS TO RNA/DNA COMPLEXES
PubMed Central
Sterpone, Fabio; Melchionna, Simone; Tuffery, Pierre; Pasquali, Samuela; Mousseau, Normand; Cragnolini, Tristan; Chebaro, Yassmine; Saint-Pierre, Jean-Francois; Kalimeri, Maria; Barducci, Alessandro; Laurin, Yohan; Tek, Alex; Baaden, Marc; Nguyen, Phuong Hoang; Derreumaux, Philippe
2015-01-01
The OPEP coarse-grained protein model has been applied to a wide range of applications since its first release 15 years ago. The model, which combines energetic and structural accuracy and chemical specificity, allows studying single protein properties, DNA/RNA complexes, amyloid fibril formation and protein suspensions in a crowded environment. Here we first review the current state of the model and the most exciting applications using advanced conformational sampling methods. We then present the current limitations and a perspective on the on-going developments. PMID:24759934
8. Coarse-Grained Structure-Based Model for RNA-Protein Complexes Developed by Fluctuation Matching.
PubMed
2012-09-11
RNA and RNA-protein complexes have recently been intensively studied in experiments, but the corresponding molecular simulation work is much less abundant, primarily due to its large system size and the long time scale involved. Here, to overcome these bottlenecks, we develop a coarse-grained (CG) structure-based simulation model for RNA and RNA-protein complexes and test it for several molecular systems. The CG model for RNA contains three particles per nucleotide, each for phosphate, sugar, and a base. Focusing on RNA molecules that fold to well-defined native structures, we employed a structure-based potential, which is similar to the Go-like potential successfully used in CG modeling of proteins. In addition, we tested three means to approximate electrostatic interactions. Many parameters involved in the CG potential were determined via a multiscale method: We matched the native fluctuation of the CG model with that by all-atom simulations for 16 RNA molecules and 10 RNA-protein complexes, from which we derived a generic set of CG parameters. We show that the derived parameters can reproduce native fluctuations well for four RNA and two RNA-protein complexes. For tRNA, the native fluctuation in solution includes large-amplitude motions that reach conformations nearly corresponding to the hybrid state P/E and EF-Tu-bound state A/T seen in the complexes with ribosome. Finally, large-amplitude modes of ribosome are briefly described.
9. Protein secondary-structure description with a coarse-grained model.
PubMed
2015-07-01
A coarse-grained geometrical model for protein secondary-structure description and analysis is presented which uses only the positions of the C(α) atoms. A space curve connecting these positions by piecewise polynomial interpolation is constructed and the folding of the protein backbone is described by a succession of screw motions linking the Frenet frames at consecutive C(α) positions. Using the ASTRAL subset of the SCOPe database of protein structures, thresholds are derived for the screw parameters of secondary-structure elements and demonstrate that the latter can be reliably assigned on the basis of a C(α) model. For this purpose, a comparative study with the widely used DSSP (Define Secondary Structure of Proteins) algorithm was performed and it was shown that the parameter distribution corresponding to the ensemble of all pure C(α) structures in the RCSB Protein Data Bank matches that of the ASTRAL database. It is expected that this approach will be useful in the development of structure-refinement techniques for low-resolution data. PMID:26143913
10. Prediction and validation of protein intermediate states from structurally rich ensembles and coarse-grained simulations
PubMed Central
Orellana, Laura; Yoluk, Ozge; Carrillo, Oliver; Orozco, Modesto; Lindahl, Erik
2016-01-01
Protein conformational changes are at the heart of cell functions, from signalling to ion transport. However, the transient nature of the intermediates along transition pathways hampers their experimental detection, making the underlying mechanisms elusive. Here we retrieve dynamic information on the actual transition routes from principal component analysis (PCA) of structurally-rich ensembles and, in combination with coarse-grained simulations, explore the conformational landscapes of five well-studied proteins. Modelling them as elastic networks in a hybrid elastic-network Brownian dynamics simulation (eBDIMS), we generate trajectories connecting stable end-states that spontaneously sample the crystallographic motions, predicting the structures of known intermediates along the paths. We also show that the explored non-linear routes can delimit the lowest energy passages between end-states sampled by atomistic molecular dynamics. The integrative methodology presented here provides a powerful framework to extract and expand dynamic pathway information from the Protein Data Bank, as well as to validate sampling methods in general. PMID:27578633
11. Prediction and validation of protein intermediate states from structurally rich ensembles and coarse-grained simulations.
PubMed
Orellana, Laura; Yoluk, Ozge; Carrillo, Oliver; Orozco, Modesto; Lindahl, Erik
2016-01-01
Protein conformational changes are at the heart of cell functions, from signalling to ion transport. However, the transient nature of the intermediates along transition pathways hampers their experimental detection, making the underlying mechanisms elusive. Here we retrieve dynamic information on the actual transition routes from principal component analysis (PCA) of structurally-rich ensembles and, in combination with coarse-grained simulations, explore the conformational landscapes of five well-studied proteins. Modelling them as elastic networks in a hybrid elastic-network Brownian dynamics simulation (eBDIMS), we generate trajectories connecting stable end-states that spontaneously sample the crystallographic motions, predicting the structures of known intermediates along the paths. We also show that the explored non-linear routes can delimit the lowest energy passages between end-states sampled by atomistic molecular dynamics. The integrative methodology presented here provides a powerful framework to extract and expand dynamic pathway information from the Protein Data Bank, as well as to validate sampling methods in general. PMID:27578633
12. Prediction and validation of protein intermediate states from structurally rich ensembles and coarse-grained simulations
Orellana, Laura; Yoluk, Ozge; Carrillo, Oliver; Orozco, Modesto; Lindahl, Erik
2016-08-01
Protein conformational changes are at the heart of cell functions, from signalling to ion transport. However, the transient nature of the intermediates along transition pathways hampers their experimental detection, making the underlying mechanisms elusive. Here we retrieve dynamic information on the actual transition routes from principal component analysis (PCA) of structurally-rich ensembles and, in combination with coarse-grained simulations, explore the conformational landscapes of five well-studied proteins. Modelling them as elastic networks in a hybrid elastic-network Brownian dynamics simulation (eBDIMS), we generate trajectories connecting stable end-states that spontaneously sample the crystallographic motions, predicting the structures of known intermediates along the paths. We also show that the explored non-linear routes can delimit the lowest energy passages between end-states sampled by atomistic molecular dynamics. The integrative methodology presented here provides a powerful framework to extract and expand dynamic pathway information from the Protein Data Bank, as well as to validate sampling methods in general.
13. De novo inference of protein function from coarse-grained dynamics.
PubMed
2014-10-01
Inference of molecular function of proteins is the fundamental task in the quest for understanding cellular processes. The task is getting increasingly difficult with thousands of new proteins discovered each day. The difficulty arises primarily due to lack of high-throughput experimental technique for assessing protein molecular function, a lacunae that computational approaches are trying hard to fill. The latter too faces a major bottleneck in absence of clear evidence based on evolutionary information. Here we propose a de novo approach to annotate protein molecular function through structural dynamics match for a pair of segments from two dissimilar proteins, which may share even <10% sequence identity. To screen these matches, corresponding 1 µs coarse-grained (CG) molecular dynamics trajectories were used to compute normalized root-mean-square-fluctuation graphs and select mobile segments, which were, thereafter, matched for all pairs using unweighted three-dimensional autocorrelation vectors. Our in-house custom-built forcefield (FF), extensively validated against dynamics information obtained from experimental nuclear magnetic resonance data, was specifically used to generate the CG dynamics trajectories. The test for correspondence of dynamics-signature of protein segments and function revealed 87% true positive rate and 93.5% true negative rate, on a dataset of 60 experimentally validated proteins, including moonlighting proteins and those with novel functional motifs. A random test against 315 unique fold/function proteins for a negative test gave >99% true recall. A blind prediction on a novel protein appears consistent with additional evidences retrieved therein. This is the first proof-of-principle of generalized use of structural dynamics for inferring protein molecular function leveraging our custom-made CG FF, useful to all.
14. Fast side chain replacement in proteins using a coarse-grained approach for evaluating the effects of mutation during evolution.
PubMed
Grahnen, Johan A; Kubelka, Jan; Liberles, David A
2011-08-01
For high-throughput structural genomic and evolutionary bioinformatics approaches, there is a clear need for fast methods to evaluate substitutions structurally. Coarse-grained methods are both powerful and fast, and a coarse-grained approach to position the substituted side chains is presented. Through the application of a coarse-grained method, a speed-up on the single- residue replacement, of at least sevenfold is achieved compared with modern all-atom approaches. At the same time, this approach maintains a small median RMSD from the leading all-atom approach (as measured in coarse-grained space), and predicts the conformation of point mutants with similar accuracy and generates biologically realistic side chain angles. This method is also substantially more predictable in its run time, making it useful for high-throughput studies of protein structural evolution. To demonstrate the utility of this method, it has been implemented in a forward simulation of sequences threaded through the SH2 domains, with selective pressures to fold and bind specifically. The relative substitution rates across the protein structure and at the binding interface are reflective of those observed in SH2 domain evolution. The algorithm has been implemented in C++, with the source code and binaries (currently supported for Linux systems) freely available as SARA at http://www.wyomingbioinformatics.org/LiberlesGroup/SARA .
15. A coarse grained protein model with internal degrees of freedom. Application to α-synuclein aggregation
Ilie, Ioana M.; den Otter, Wouter K.; Briels, Wim J.
2016-02-01
Particles in simulations are traditionally endowed with fixed interactions. While this is appropriate for particles representing atoms or molecules, objects with significant internal dynamics—like sequences of amino acids or even an entire protein—are poorly modelled by invariable particles. We develop a highly coarse grained polymorph patchy particle with the ultimate aim of simulating proteins as chains of particles at the secondary structure level. Conformational changes, e.g., a transition between disordered and β-sheet states, are accommodated by internal coordinates that determine the shape and interaction characteristics of the particles. The internal coordinates, as well as the particle positions and orientations, are propagated by Brownian Dynamics in response to their local environment. As an example of the potential offered by polymorph particles, we model the amyloidogenic intrinsically disordered protein α-synuclein, involved in Parkinson's disease, as a single particle with two internal states. The simulations yield oligomers of particles in the disordered state and fibrils of particles in the "misfolded" cross-β-sheet state. The aggregation dynamics is complex, as aggregates can form by a direct nucleation-and-growth mechanism and by two-step-nucleation through conversions between the two cluster types. The aggregation dynamics is complex, with fibrils formed by direct nucleation-and-growth, by two-step-nucleation through the conversion of an oligomer and by auto-catalysis of this conversion.
16. REACH Coarse-Grained Normal Mode Analysis of Protein Dimer Interaction Dynamics
PubMed Central
Moritsugu, Kei; Kurkal-Siebert, Vandana; Smith, Jeremy C.
2009-01-01
Abstract The REACH (realistic extension algorithm via covariance Hessian) coarse-grained biomolecular simulation method is a self-consistent multiscale approach directly mapping atomistic molecular dynamics simulation results onto a residue-scale model. Here, REACH is applied to calculate the dynamics of protein-protein interactions. The intra- and intermolecular fluctuations and the intermolecular vibrational densities of states derived from atomistic molecular dynamics are well reproduced by the REACH normal modes. The phonon dispersion relations derived from the REACH lattice dynamics model of crystalline ribonuclease A are also in satisfactory agreement with the corresponding all-atom results. The REACH model demonstrates that increasing dimer interaction strength decreases the translational and rotational intermolecular vibrational amplitudes, while their vibrational frequencies are relatively unaffected. A comparative study of functionally interacting biological dimers with crystal dimers, which are formed artificially via crystallization, reveals a relation between their static structures and the interprotein dynamics: i.e., the consequence of the extensive interfaces of biological dimers is reduction of the intermonomer translational and rotational amplitudes, but not the frequencies. PMID:19686664
17. Validating a Coarse-Grained Potential Energy Function through Protein Loop Modelling
PubMed Central
MacDonald, James T.; Kelley, Lawrence A.; Freemont, Paul S.
2013-01-01
Coarse-grained (CG) methods for sampling protein conformational space have the potential to increase computational efficiency by reducing the degrees of freedom. The gain in computational efficiency of CG methods often comes at the expense of non-protein like local conformational features. This could cause problems when transitioning to full atom models in a hierarchical framework. Here, a CG potential energy function was validated by applying it to the problem of loop prediction. A novel method to sample the conformational space of backbone atoms was benchmarked using a standard test set consisting of 351 distinct loops. This method used a sequence-independent CG potential energy function representing the protein using -carbon positions only and sampling conformations with a Monte Carlo simulated annealing based protocol. Backbone atoms were added using a method previously described and then gradient minimised in the Rosetta force field. Despite the CG potential energy function being sequence-independent, the method performed similarly to methods that explicitly use either fragments of known protein backbones with similar sequences or residue-specific /-maps to restrict the search space. The method was also able to predict with sub-Angstrom accuracy two out of seven loops from recently solved crystal structures of proteins with low sequence and structure similarity to previously deposited structures in the PDB. The ability to sample realistic loop conformations directly from a potential energy function enables the incorporation of additional geometric restraints and the use of more advanced sampling methods in a way that is not possible to do easily with fragment replacement methods and also enable multi-scale simulations for protein design and protein structure prediction. These restraints could be derived from experimental data or could be design restraints in the case of computational protein design. C++ source code is available for download from http
18. Solvating atomic level fine-grained proteins in supra-molecular level coarse-grained water for molecular dynamics simulations.
PubMed
Riniker, Sereina; Eichenberger, Andreas P; van Gunsteren, Wilfred F
2012-08-01
Simulation of the dynamics of a protein in aqueous solution using an atomic model for both the protein and the many water molecules is still computationally extremely demanding considering the time scale of protein motions. The use of supra-atomic or supra-molecular coarse-grained (CG) models may enhance the computational efficiency, but inevitably at the cost of reduced accuracy. Coarse-graining solvent degrees of freedom is likely to yield a favourable balance between reduced accuracy and enhanced computational speed. Here, the use of a supra-molecular coarse-grained water model that largely preserves the thermodynamic and dielectric properties of atomic level fine-grained (FG) water in molecular dynamics simulations of an atomic model for four proteins is investigated. The results of using an FG, a CG, an implicit, or a vacuum solvent environment of the four proteins are compared, and for hen egg-white lysozyme a comparison to NMR data is made. The mixed-grained simulations do not show large differences compared to the FG atomic level simulations, apart from an increased tendency to form hydrogen bonds between long side chains, which is due to the reduced ability of the supra-molecular CG beads that represent five FG water molecules to make solvent-protein hydrogen bonds. But, the mixed-grained simulations are at least an order of magnitude faster than the atomic level ones.
19. Multi-scale morphology in self-assembly of peptides to proteins via a coarse-grain model
Pandey, Ras; Farmer, Barry
2015-03-01
Self-organizing structures of short peptides (6-7 residues) and proteins (136 residues) are studied by a coarse-grained Monte Carlo simulation. Peptides and proteins are described by coarse-grained chains of residues whose interactions are described by a knowledge-based residue-residue interaction potential that captures the compositional specificity. Large-scale computer simulations are performed to study the structural evolution e.g. aggregation, network, etc. at a range of temperatures and concentrations. A number of local and global physical quantities including structure factor are examined. We find that the residue interactions, concentration, and size of chains are very important in modulating the structure of emerging morphologies in the specified temperature range. Estimates are provided for the effective (fractal) dimension of the assembly over various length scales as a function of temperature. This work is supported by the Air Force Research Laboratory.
20. Coarse-grained molecular dynamics of ligands binding into protein: The case of HIV-1 protease inhibitors
Li, Dechang; Liu, Ming S.; Ji, Baohua; Hwang, Kehchih; Huang, Yonggang
2009-06-01
Binding dynamics and pathways of ligands or inhibitors to target proteins are challenging both experimental and theoretical biologists. A dynamics understanding of inhibitors interacting with protein is essential for the design of novel potent drugs. In this work we applied a coarse-grained molecular dynamics method for simulating inhibitors entering the binding cavity of human immunodeficiency virus type 1 protease (PR). It shows that the coarse-grained dynamics, consistent with the experimental results, can capture the essential molecular dynamics of various inhibitors binding into PR. The primary driving force for the binding processes is the nonbond interaction between inhibitors and PR. The size and topology of inhibitors and the interacting strength between inhibitors and PR have great influence on the binding mode and processes. The interaction strength between the PR and various inhibitors is also analyzed by atomistic molecular mechanics and Poisson-Boltzmann solvation area method.
1. Sliding of proteins non-specifically bound to DNA: Brownian dynamics studies with coarse-grained protein and DNA models.
PubMed
2014-12-01
DNA binding proteins efficiently search for their cognitive sites on long genomic DNA by combining 3D diffusion and 1D diffusion (sliding) along the DNA. Recent experimental results and theoretical analyses revealed that the proteins show a rotation-coupled sliding along DNA helical pitch. Here, we performed Brownian dynamics simulations using newly developed coarse-grained protein and DNA models for evaluating how hydrodynamic interactions between the protein and DNA molecules, binding affinity of the protein to DNA, and DNA fluctuations affect the one dimensional diffusion of the protein on the DNA. Our results indicate that intermolecular hydrodynamic interactions reduce 1D diffusivity by 30%. On the other hand, structural fluctuations of DNA give rise to steric collisions between the CG-proteins and DNA, resulting in faster 1D sliding of the protein. Proteins with low binding affinities consistent with experimental estimates of non-specific DNA binding show hopping along the CG-DNA. This hopping significantly increases sliding speed. These simulation studies provide additional insights into the mechanism of how DNA binding proteins find their target sites on the genome.
2. Modeling protein conformational transitions by a combination of coarse-grained normal mode analysis and robotics-inspired methods
PubMed Central
2013-01-01
Background Obtaining atomic-scale information about large-amplitude conformational transitions in proteins is a challenging problem for both experimental and computational methods. Such information is, however, important for understanding the mechanisms of interaction of many proteins. Methods This paper presents a computationally efficient approach, combining methods originating from robotics and computational biophysics, to model protein conformational transitions. The ability of normal mode analysis to predict directions of collective, large-amplitude motions is applied to bias the conformational exploration performed by a motion planning algorithm. To reduce the dimension of the problem, normal modes are computed for a coarse-grained elastic network model built on short fragments of three residues. Nevertheless, the validity of intermediate conformations is checked using the all-atom model, which is accurately reconstructed from the coarse-grained one using closed-form inverse kinematics. Results Tests on a set of ten proteins demonstrate the ability of the method to model conformational transitions of proteins within a few hours of computing time on a single processor. These results also show that the computing time scales linearly with the protein size, independently of the protein topology. Further experiments on adenylate kinase show that main features of the transition between the open and closed conformations of this protein are well captured in the computed path. Conclusions The proposed method enables the simulation of large-amplitude conformational transitions in proteins using very few computational resources. The resulting paths are a first approximation that can directly provide important information on the molecular mechanisms involved in the conformational transition. This approximation can be subsequently refined and analyzed using state-of-the-art energy models and molecular modeling methods. PMID:24564964
3. Folding 19 proteins to their native state and stability of large proteins from a coarse-grained model.
PubMed
Kapoor, Abhijeet; Travesset, Alex
2014-03-01
We develop an intermediate resolution model, where the backbone is modeled with atomic resolution but the side chain with a single bead, by extending our previous model (Proteins (2013) DOI: 10.1002/prot.24269) to properly include proline, preproline residues and backbone rigidity. Starting from random configurations, the model properly folds 19 proteins (including a mutant 2A3D sequence) into native states containing β sheet, α helix, and mixed α/β. As a further test, the stability of H-RAS (a 169 residue protein, critical in many signaling pathways) is investigated: The protein is stable, with excellent agreement with experimental B-factors. Despite that proteins containing only α helices fold to their native state at lower backbone rigidity, and other limitations, which we discuss thoroughly, the model provides a reliable description of the dynamics as compared with all atom simulations, but does not constrain secondary structures as it is typically the case in more coarse-grained models. Further implications are described.
4. Structure and dynamics of Ebola virus matrix protein VP40 by a coarse-grained Monte Carlo simulation
Pandey, Ras; Farmer, Barry
Ebola virus matrix protein VP40 (consisting of 326 residues) plays a critical role in viral assembly and its functions such as regulation of viral transcription, packaging, and budding of mature virions into the plasma membrane of infected cells. How does the protein VP40 go through structural evolution during the viral life cycle remains an open question? Using a coarse-grained Monte Carlo simulation we investigate the structural evolution of VP40 as a function of temperature with the input of a knowledge-based residue-residue interaction. A number local and global physical quantities (e.g. mobility profile, contact map, radius of gyration, structure factor) are analyzed with our large-scale simulations. Our preliminary data show that the structure of the protein evolves through different state with well-defined morphologies which can be identified and quantified via a detailed analysis of structure factor.
5. SIRAH: a structurally unbiased coarse-grained force field for proteins with aqueous solvation and long-range electrostatics.
PubMed
Darré, Leonardo; Machado, Matías Rodrigo; Brandner, Astrid Febe; González, Humberto Carlos; Ferreira, Sebastián; Pantano, Sergio
2015-02-10
Modeling of macromolecular structures and interactions represents an important challenge for computational biology, involving different time and length scales. However, this task can be facilitated through the use of coarse-grained (CG) models, which reduce the number of degrees of freedom and allow efficient exploration of complex conformational spaces. This article presents a new CG protein model named SIRAH, developed to work with explicit solvent and to capture sequence, temperature, and ionic strength effects in a topologically unbiased manner. SIRAH is implemented in GROMACS, and interactions are calculated using a standard pairwise Hamiltonian for classical molecular dynamics simulations. We present a set of simulations that test the capability of SIRAH to produce a qualitatively correct solvation on different amino acids, hydrophilic/hydrophobic interactions, and long-range electrostatic recognition leading to spontaneous association of unstructured peptides and stable structures of single polypeptides and protein-protein complexes. PMID:26575407
6. Temperature-enhanced association of proteins due to electrostatic interaction: a coarse-grained simulation of actin-myosin binding.
PubMed
Okazaki, Kei-ichi; Sato, Takato; Takano, Mitsunori
2012-05-30
Association of protein molecules constitutes the basis for the interaction network in a cell. Despite its fundamental importance, the thermodynamic aspect of protein-protein binding, particularly the issues relating to the entropy change upon binding, remains elusive. The binding of actin and myosin, which are vital proteins in motility, is a typical example, in which two different binding mechanisms have been argued: the binding affinity increases with increasing temperature and with decreasing salt-concentration, indicating the entropy-driven binding and the enthalpy-driven binding, respectively. How can these thermodynamically different binding mechanisms coexist? To address this question, which is of general importance in understanding protein-protein bindings, we conducted an in silico titration of the actin-myosin system by molecular dynamics simulation using a residue-level coarse-grained model, with particular focus on the role of the electrostatic interaction. We found a good agreement between in silico and in vitro experiments on the salt-concentration dependence and the temperature dependence of the binding affinity. We then figured out how the two binding mechanisms can coexist: the enthalpy (due to electrostatic interaction between actin and myosin) provides the basal binding affinity, and the entropy (due to the orientational disorder of water molecules) enhances it at higher temperatures. In addition, we analyzed the actin-myosin complex structures observed during the simulation and obtained a variety of weak-binding complex structures, among which were found an unusual binding mode suggested by an earlier experiment and precursor structures of the strong-binding complex proposed by electron microscopy. These results collectively indicate the potential capability of a residue-level coarse-grained model to simulate the association-dissociation dynamics (particularly for transient weak-bindings) exhibited by larger and more complicated systems, as in a
7. Tunable Coarse Graining for Monte Carlo Simulations of Proteins via Smoothed Energy Tables: Direct and Exchange Simulations
PubMed Central
2015-01-01
Many commonly used coarse-grained models for proteins are based on simplified interaction sites and consequently may suffer from significant limitations, such as the inability to properly model protein secondary structure without the addition of restraints. Recent work on a benzene fluid (LettieriS.; ZuckermanD. M.J. Comput. Chem.2012, 33, 268−27522120971) suggested an alternative strategy of tabulating and smoothing fully atomistic orientation-dependent interactions among rigid molecules or fragments. Here we report our initial efforts to apply this approach to the polar and covalent interactions intrinsic to polypeptides. We divide proteins into nearly rigid fragments, construct distance and orientation-dependent tables of the atomistic interaction energies between those fragments, and apply potential energy smoothing techniques to those tables. The amount of smoothing can be adjusted to give coarse-grained models that range from the underlying atomistic force field all the way to a bead-like coarse-grained model. For a moderate amount of smoothing, the method is able to preserve about 70–90% of the α-helical structure while providing a factor of 3–10 improvement in sampling per unit computation time (depending on how sampling is measured). For a greater amount of smoothing, multiple folding–unfolding transitions of the peptide were observed, along with a factor of 10–100 improvement in sampling per unit computation time, although the time spent in the unfolded state was increased compared with less smoothed simulations. For a β hairpin, secondary structure is also preserved, albeit for a narrower range of the smoothing parameter and, consequently, for a more modest improvement in sampling. We have also applied the new method in a “resolution exchange” setting, in which each replica runs a Monte Carlo simulation with a different degree of smoothing. We obtain exchange rates that compare favorably to our previous efforts at resolution exchange
8. Discriminating binding mechanisms of an intrinsically disordered protein via a multi-state coarse-grained model
SciTech Connect
Knott, Michael; Best, Robert B.
2014-05-07
Many proteins undergo a conformational transition upon binding to their cognate binding partner, with intrinsically disordered proteins (IDPs) providing an extreme example in which a folding transition occurs. However, it is often not clear whether this occurs via an “induced fit” or “conformational selection” mechanism, or via some intermediate scenario. In the first case, transient encounters with the binding partner favour transitions to the bound structure before the two proteins dissociate, while in the second the bound structure must be selected from a subset of unbound structures which are in the correct state for binding, because transient encounters of the incorrect conformation with the binding partner are most likely to result in dissociation. A particularly interesting situation involves those intrinsically disordered proteins which can bind to different binding partners in different conformations. We have devised a multi-state coarse-grained simulation model which is able to capture the binding of IDPs in alternate conformations, and by applying it to the binding of nuclear coactivator binding domain (NCBD) to either ACTR or IRF-3 we are able to determine the binding mechanism. By all measures, the binding of NCBD to either binding partner appears to occur via an induced fit mechanism. Nonetheless, we also show how a scenario closer to conformational selection could arise by choosing an alternative non-binding structure for NCBD.
9. Computational Calculation Of The Ionization Energies Of The Human Prion Protein By The Coarse-grain Method
Lyu, Justin; Andrianarijaona, V. M.
2016-05-01
The causes of the misfolding of prion protein -i.e. the transformation of PrPC to PrPSc - have not been clearly elucidated. Many studies have focused on identifying possible chemical conditions, such as pH, temperature and chemical denaturation, that may trigger the pathological transformation of prion proteins (Weiwei Tao, Gwonchan Yoon, Penghui Cao, β-sheet-like formation during the mechanical unfolding of prion protein'', The Journal of Chemical Physics, 2015, 143, 125101). Here, we attempt to calculate the ionization energies of the prion protein, which will be able to shed light onto the possible causes of the misfolding. We plan on using the coarse-grain method which allows for a more feasible calculation time by means of approximation. We believe that by being able to approximate the ionization potential, particularly that of the regions known to form stable β-strands of the PrPSc form, the possible sources of denaturation, be it chemical or mechanical, may be narrowed down.
10. AWSEM-MD: Protein Structure Prediction Using Coarse-grained Physical Potentials and Bioinformatically Based Local Structure Biasing
PubMed Central
Davtyan, Aram; Schafer, Nicholas P.; Zheng, Weihua; Clementi, Cecilia; Wolynes, Peter G.; Papoian, Garegin A.
2012-01-01
The Associative memory, Water mediated, Structure and Energy Model (AWSEM) is a coarse-grained protein force field. AWSEM contains physically motivated terms, such as hydrogen bonding, as well as a bioinformatically based local structure biasing term, which efficiently takes into account many-body effects that are modulated by the local sequence. When combined with appropriate local or global alignments to choose memories, AWSEM can be used to perform de novo protein structure prediction. Herein we present structure prediction results for a particular choice of local sequence alignment method based on short residue sequences called fragments. We demonstrate the model’s structure prediction capabilities for three levels of global homology between the target sequence and those proteins used for local structure biasing, all of which assume that the structure of the target sequence is not known. When there are no homologs in the database of structures used for local structure biasing, AWSEM calculations produce structural predictions that are somewhat improved compared with prior works using related approaches. The inclusion of a small number of structures from homologous sequences improves structure prediction only marginally but when the fragment search is restricted to only homologous sequences, AWSEM can perform high resolution structure prediction and can be used for kinetics and dynamics studies. PMID:22545654
11. Three-Dimensional Stress Field around a Membrane Protein: Atomistic and Coarse-Grained Simulation Analysis of Gramicidin A
PubMed Central
Yoo, Jejoong; Cui, Qiang
2013-01-01
Using both atomistic and coarse-grained (CG) models, we compute the three-dimensional stress field around a gramicidin A (gA) dimer in lipid bilayers that feature different degrees of negative hydrophobic mismatch. The general trends in the computed stress field are similar at the atomistic and CG levels, supporting the use of the CG model for analyzing the mechanical features of protein/lipid/water interfaces. The calculations reveal that the stress field near the protein-lipid interface exhibits a layered structure with both significant repulsive and attractive regions, with the magnitude of the stress reaching 1000 bar in certain regions. Analysis of density profiles and stress field distributions helps highlight the Trp residues at the protein/membrane/water interface as mechanical anchors, suggesting that similar analysis is useful for identifying tension sensors in other membrane proteins, especially membrane proteins involved in mechanosensation. This work fosters a connection between microscopic and continuum mechanics models for proteins in complex environments and makes it possible to test the validity of assumptions commonly made in continuum mechanics models for membrane mediated processes. For example, using the calculated stress field, we estimate the free energy of membrane deformation induced by the hydrophobic mismatch, and the results for regions beyond the annular lipids are in general consistent with relevant experimental data and previous theoretical estimates using elasticity theory. On the other hand, the assumptions of homogeneous material properties for the membrane and a bilayer thickness at the protein/lipid interface being independent of lipid type (e.g., tail length) appear to be oversimplified, highlighting the importance of annular lipids of membrane proteins. Finally, the stress field analysis makes it clear that the effect of even rather severe hydrophobic mismatch propagates to only about two to three lipid layers, thus putting a
12. Three-dimensional stress field around a membrane protein: atomistic and coarse-grained simulation analysis of gramicidin A.
PubMed
Yoo, Jejoong; Cui, Qiang
2013-01-01
Using both atomistic and coarse-grained (CG) models, we compute the three-dimensional stress field around a gramicidin A (gA) dimer in lipid bilayers that feature different degrees of negative hydrophobic mismatch. The general trends in the computed stress field are similar at the atomistic and CG levels, supporting the use of the CG model for analyzing the mechanical features of protein/lipid/water interfaces. The calculations reveal that the stress field near the protein-lipid interface exhibits a layered structure with both significant repulsive and attractive regions, with the magnitude of the stress reaching 1000 bar in certain regions. Analysis of density profiles and stress field distributions helps highlight the Trp residues at the protein/membrane/water interface as mechanical anchors, suggesting that similar analysis is useful for identifying tension sensors in other membrane proteins, especially membrane proteins involved in mechanosensation. This work fosters a connection between microscopic and continuum mechanics models for proteins in complex environments and makes it possible to test the validity of assumptions commonly made in continuum mechanics models for membrane mediated processes. For example, using the calculated stress field, we estimate the free energy of membrane deformation induced by the hydrophobic mismatch, and the results for regions beyond the annular lipids are in general consistent with relevant experimental data and previous theoretical estimates using elasticity theory. On the other hand, the assumptions of homogeneous material properties for the membrane and a bilayer thickness at the protein/lipid interface being independent of lipid type (e.g., tail length) appear to be oversimplified, highlighting the importance of annular lipids of membrane proteins. Finally, the stress field analysis makes it clear that the effect of even rather severe hydrophobic mismatch propagates to only about two to three lipid layers, thus putting a
13. Coarse-grained molecular simulation of epidermal growth factor receptor protein tyrosine kinase multi-site self-phosphorylation.
PubMed
Koland, John G
2014-01-01
Upon the ligand-dependent dimerization of the epidermal growth factor receptor (EGFR), the intrinsic protein tyrosine kinase (PTK) activity of one receptor monomer is activated, and the dimeric receptor undergoes self-phosphorylation at any of eight candidate phosphorylation sites (P-sites) in either of the two C-terminal (CT) domains. While the structures of the extracellular ligand binding and intracellular PTK domains are known, that of the ∼225-amino acid CT domain is not, presumably because it is disordered. Receptor phosphorylation on CT domain P-sites is critical in signaling because of the binding of specific signaling effector molecules to individual phosphorylated P-sites. To investigate how the combination of conventional substrate recognition and the unique topological factors involved in the CT domain self-phosphorylation reaction lead to selectivity in P-site phosphorylation, we performed coarse-grained molecular simulations of the P-site/catalytic site binding reactions that precede EGFR self-phosphorylation events. Our results indicate that self-phosphorylation of the dimeric EGFR, although generally believed to occur in trans, may well occur with a similar efficiency in cis, with the P-sites of both receptor monomers being phosphorylated to a similar extent. An exception was the case of the most kinase-proximal P-site-992, the catalytic site binding of which occurred exclusively in cis via an intramolecular reaction. We discovered that the in cis interaction of P-site-992 with the catalytic site was facilitated by a cleft between the N-terminal and C-terminal lobes of the PTK domain that allows the short CT domain sequence tethering P-site-992 to the PTK core to reach the catalytic site. Our work provides several new mechanistic insights into the EGFR self-phosphorylation reaction, and demonstrates the potential of coarse-grained molecular simulation approaches for investigating the complexities of self-phosphorylation in molecules such as EGFR
14. Efficient Parameter Estimation of Generalizable Coarse-Grained Protein Force Fields Using Contrastive Divergence: A Maximum Likelihood Approach
PubMed Central
2013-01-01
Maximum Likelihood (ML) optimization schemes are widely used for parameter inference. They maximize the likelihood of some experimentally observed data, with respect to the model parameters iteratively, following the gradient of the logarithm of the likelihood. Here, we employ a ML inference scheme to infer a generalizable, physics-based coarse-grained protein model (which includes Go̅-like biasing terms to stabilize secondary structure elements in room-temperature simulations), using native conformations of a training set of proteins as the observed data. Contrastive divergence, a novel statistical machine learning technique, is used to efficiently approximate the direction of the gradient ascent, which enables the use of a large training set of proteins. Unlike previous work, the generalizability of the protein model allows the folding of peptides and a protein (protein G) which are not part of the training set. We compare the same force field with different van der Waals (vdW) potential forms: a hard cutoff model, and a Lennard-Jones (LJ) potential with vdW parameters inferred or adopted from the CHARMM or AMBER force fields. Simulations of peptides and protein G show that the LJ model with inferred parameters outperforms the hard cutoff potential, which is consistent with previous observations. Simulations using the LJ potential with inferred vdW parameters also outperforms the protein models with adopted vdW parameter values, demonstrating that model parameters generally cannot be used with force fields with different energy functions. The software is available at https://sites.google.com/site/crankite/. PMID:24683370
15. Transferable Coarse-Grained Potential for De Novo Protein Folding and Design
PubMed Central
Coluzza, Ivan
2014-01-01
Protein folding and design are major biophysical problems, the solution of which would lead to important applications especially in medicine. Here we provide evidence of how a novel parametrization of the Caterpillar model may be used for both quantitative protein design and folding. With computer simulations it is shown that, for a large set of real protein structures, the model produces designed sequences with similar physical properties to the corresponding natural occurring sequences. The designed sequences require further experimental testing. For an independent set of proteins, previously used as benchmark, the correct folded structure of both the designed and the natural sequences is also demonstrated. The equilibrium folding properties are characterized by free energy calculations. The resulting free energy profiles not only are consistent among natural and designed proteins, but also show a remarkable precision when the folded structures are compared to the experimentally determined ones. Ultimately, the updated Caterpillar model is unique in the combination of its fundamental three features: its simplicity, its ability to produce natural foldable designed sequences, and its structure prediction precision. It is also remarkable that low frustration sequences can be obtained with such a simple and universal design procedure, and that the folding of natural proteins shows funnelled free energy landscapes without the need of any potentials based on the native structure. PMID:25436908
16. Tabulation as a high-resolution alternative to coarse-graining protein interactions: Initial application to virus capsid subunits
Spiriti, Justin; Zuckerman, Daniel M.
2015-12-01
Traditional coarse-graining based on a reduced number of interaction sites often entails a significant sacrifice of chemical accuracy. As an alternative, we present a method for simulating large systems composed of interacting macromolecules using an energy tabulation strategy previously devised for small rigid molecules or molecular fragments [S. Lettieri and D. M. Zuckerman, J. Comput. Chem. 33, 268-275 (2012); J. Spiriti and D. M. Zuckerman, J. Chem. Theory Comput. 10, 5161-5177 (2014)]. We treat proteins as rigid and construct distance and orientation-dependent tables of the interaction energy between them. Arbitrarily detailed interactions may be incorporated into the tables, but as a proof-of-principle, we tabulate a simple α-carbon Gō-like model for interactions between dimeric subunits of the hepatitis B viral capsid. This model is significantly more structurally realistic than previous models used in capsid assembly studies. We are able to increase the speed of Monte Carlo simulations by a factor of up to 6700 compared to simulations without tables, with only minimal further loss in accuracy. To obtain further enhancement of sampling, we combine tabulation with the weighted ensemble (WE) method, in which multiple parallel simulations are occasionally replicated or pruned in order to sample targeted regions of a reaction coordinate space. In the initial study reported here, WE is able to yield pathways of the final ˜25% of the assembly process.
17. Kinetics of fragmentation and dissociation of two-strand protein filaments: Coarse-grained simulations and experiments.
PubMed
Zaccone, A; Terentjev, I; Herling, T W; Knowles, T P J; Aleksandrova, A; Terentjev, E M
2016-09-14
While a significant body of investigations have been focused on the process of protein self-assembly, much less is understood about the reverse process of a filament breaking due to thermal motion into smaller fragments, or depolymerization of subunits from the filament ends. Indirect evidence for actin and amyloid filament fragmentation has been reported, although the phenomenon has never been directly observed either experimentally or in simulations. Here we report the direct observation of filament depolymerization and breakup in a minimal, calibrated model of coarse-grained molecular simulation. We quantify the orders of magnitude by which the depolymerization rate from the filament ends koff is larger than fragmentation rate k- and establish the law koff/k- = exp[(ε‖ - ε⊥)/kBT] = exp[0.5ε/kBT], which accounts for the topology and energy of bonds holding the filament together. This mechanism and the order-of-magnitude predictions are well supported by direct experimental measurements of depolymerization of insulin amyloid filaments. PMID:27634278
18. Kinetics of fragmentation and dissociation of two-strand protein filaments: Coarse-grained simulations and experiments
Zaccone, A.; Terentjev, I.; Herling, T. W.; Knowles, T. P. J.; Aleksandrova, A.; Terentjev, E. M.
2016-09-01
While a significant body of investigations have been focused on the process of protein self-assembly, much less is understood about the reverse process of a filament breaking due to thermal motion into smaller fragments, or depolymerization of subunits from the filament ends. Indirect evidence for actin and amyloid filament fragmentation has been reported, although the phenomenon has never been directly observed either experimentally or in simulations. Here we report the direct observation of filament depolymerization and breakup in a minimal, calibrated model of coarse-grained molecular simulation. We quantify the orders of magnitude by which the depolymerization rate from the filament ends koff is larger than fragmentation rate k- and establish the law koff/k- = exp[(ɛ‖ - ɛ⊥)/kBT] = exp[0.5ɛ/kBT], which accounts for the topology and energy of bonds holding the filament together. This mechanism and the order-of-magnitude predictions are well supported by direct experimental measurements of depolymerization of insulin amyloid filaments.
19. On the application of the MARTINI coarse-grained model to immersion of a protein in a phospholipid bilayer
Mustafa, Ghulam; Nandekar, Prajwal P.; Yu, Xiaofeng; Wade, Rebecca C.
2015-12-01
An important step in the simulation of a membrane protein in a phospholipid bilayer is the correct immersion of the protein in the bilayer. Crystal structures are determined without the bilayer. Particularly for proteins with monotopic domains, it can be unclear how deeply and in which orientation the protein is being inserted in the membrane. We have previously developed a procedure combining coarse-grain (CG) with all-atom (AA) molecular dynamics (MD) simulations to insert and simulate a cytochrome P450 (CYP) possessing an N-terminal transmembrane helix connected by a flexible linker region to a globular domain that dips into the membrane. The CG simulations provide a computationally efficient means to explore different orientations and conformations of the CYP in the membrane. Converged configurations obtained in the CG simulations are then refined in AA simulations. Here, we tested different variants of the MARTINI CG model, differing in the water model, the treatment of long-range non-bonded interactions, and the implementation (GROMACS 4.5.5 vs 5.0.4), for this purpose. We examined the behavior of the models for simulating a 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) bilayer in water and for the immersion of CYP3A4 in a POPC bilayer, and compared the CG-MD results with the previously reported experimental and simulation results. We also tested the methodology on a set of four other CYPs. Finally, we propose an optimized protocol for modeling such protein-membrane systems that provides the most plausible configurations and is computationally efficient; this incorporates the standard non-polar water model and the GROMACS 5.0.4 implementation with a reaction field treatment of long-range interactions.
20. On the application of the MARTINI coarse-grained model to immersion of a protein in a phospholipid bilayer
SciTech Connect
2015-12-28
An important step in the simulation of a membrane protein in a phospholipid bilayer is the correct immersion of the protein in the bilayer. Crystal structures are determined without the bilayer. Particularly for proteins with monotopic domains, it can be unclear how deeply and in which orientation the protein is being inserted in the membrane. We have previously developed a procedure combining coarse-grain (CG) with all-atom (AA) molecular dynamics (MD) simulations to insert and simulate a cytochrome P450 (CYP) possessing an N-terminal transmembrane helix connected by a flexible linker region to a globular domain that dips into the membrane. The CG simulations provide a computationally efficient means to explore different orientations and conformations of the CYP in the membrane. Converged configurations obtained in the CG simulations are then refined in AA simulations. Here, we tested different variants of the MARTINI CG model, differing in the water model, the treatment of long-range non-bonded interactions, and the implementation (GROMACS 4.5.5 vs 5.0.4), for this purpose. We examined the behavior of the models for simulating a 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) bilayer in water and for the immersion of CYP3A4 in a POPC bilayer, and compared the CG-MD results with the previously reported experimental and simulation results. We also tested the methodology on a set of four other CYPs. Finally, we propose an optimized protocol for modeling such protein-membrane systems that provides the most plausible configurations and is computationally efficient; this incorporates the standard non-polar water model and the GROMACS 5.0.4 implementation with a reaction field treatment of long-range interactions.
1. Transferring the PRIMO Coarse-Grained Force Field to the Membrane Environment: Simulations of Membrane Proteins and Helix-Helix Association.
PubMed
Kar, Parimal; Gopal, Srinivasa Murthy; Cheng, Yi-Ming; Panahi, Afra; Feig, Michael
2014-08-12
An extension of the recently developed PRIMO coarse-grained force field to membrane environments, PRIMO-M, is described. The membrane environment is modeled with the heterogeneous dielectric generalized Born (HDGB) methodology that simply replaces the standard generalized Born model in PRIMO without further parametrization. The resulting model was validated by comparing amino acid insertion free energy profiles and application in molecular dynamics simulations of membrane proteins and membrane-interacting peptides. Membrane proteins with 148-661 amino acids show stable root-mean-squared-deviations (RMSD) between 2 and 4 Å for most systems. Transmembrane helical peptides maintain helical shape and exhibit tilt angles in good agreement with experimental or other simulation data. The association of two glycophorin A (GpA) helices was simulated using replica exchange molecular dynamics simulations yielding the correct dimer structure with a crossing angle in agreement with previous studies. Finally, conformational sampling of the influenza fusion peptide also generates structures in agreement with previous studies. Overall, these findings suggest that PRIMO-M can be used to study membrane bound peptides and proteins and validates the transferable nature of the PRIMO coarse-grained force field.
2. COFFDROP: A Coarse-Grained Nonbonded Force Field for Proteins Derived from All-Atom Explicit-Solvent Molecular Dynamics Simulations of Amino Acids
PubMed Central
2015-01-01
We describe the derivation of a set of bonded and nonbonded coarse-grained (CG) potential functions for use in implicit-solvent Brownian dynamics (BD) simulations of proteins derived from all-atom explicit-solvent molecular dynamics (MD) simulations of amino acids. Bonded potential functions were derived from 1 μs MD simulations of each of the 20 canonical amino acids, with histidine modeled in both its protonated and neutral forms; nonbonded potential functions were derived from 1 μs MD simulations of every possible pairing of the amino acids (231 different systems). The angle and dihedral probability distributions and radial distribution functions sampled during MD were used to optimize a set of CG potential functions through use of the iterative Boltzmann inversion (IBI) method. The optimized set of potential functions—which we term COFFDROP (COarse-grained Force Field for Dynamic Representation Of Proteins)—quantitatively reproduced all of the “target” MD distributions. In a first test of the force field, it was used to predict the clustering behavior of concentrated amino acid solutions; the predictions were directly compared with the results of corresponding all-atom explicit-solvent MD simulations and found to be in excellent agreement. In a second test, BD simulations of the small protein villin headpiece were carried out at concentrations that have recently been studied in all-atom explicit-solvent MD simulations by Petrov and Zagrovic (PLoS Comput. Biol.2014, 5, e1003638). The anomalously strong intermolecular interactions seen in the MD study were reproduced in the COFFDROP simulations; a simple scaling of COFFDROP’s nonbonded parameters, however, produced results in better accordance with experiment. Overall, our results suggest that potential functions derived from simulations of pairwise amino acid interactions might be of quite broad applicability, with COFFDROP likely to be especially useful for modeling unfolded or intrinsically
3. Membrane-mediated protein-protein interactions and connection to elastic models: a coarse-grained simulation analysis of gramicidin A association.
PubMed
Yoo, Jejoong; Cui, Qiang
2013-01-01
To further foster the connection between particle based and continuum mechanics models for membrane mediated biological processes, we carried out coarse-grained (CG) simulations of gramicidin A (gA) dimer association and analyzed the results based on the combination of potential of mean force (PMF) and stress field calculations. Similar to previous studies, we observe that the association of gA dimers depends critically on the degree of hydrophobic mismatch, with the estimated binding free energy of >10 kcal/mol in a distearoylphosphatidylcholine bilayer. Qualitative trends in the computed PMF can be understood based on the stress field distributions near a single gA dimer and between a pair of gA dimers. For example, the small PMF barrier, which is ∼1 kcal/mol independent of lipid type, can be captured nearly quantitatively by considering membrane deformation energy associated with the region confined by two gA dimers. However, the PMF well depth is reproduced poorly by a simple continuum model that only considers membrane deformation energy beyond the annular lipids. Analysis of lipid orientation, configuration entropy, and stress distribution suggests that the annular lipids make a significant contribution to the association of two gA dimers. These results highlight the importance of explicitly considering contributions from annular lipids when constructing approximate models to study processes that involve a significant reorganization of lipids near proteins, such as protein-protein association and protein insertion into biomembranes. Finally, large-scale CG simulations indicate that multiple gA dimers also form clusters, although the preferred topology depends on the protein concentration. Even at high protein concentrations, every gA dimer requires contact to lipid hydrocarbons to some degree, and at most three to four proteins are in contact with each gA dimer; this observation highlights another aspect of the importance of interactions between proteins
4. The Theory of Ultra Coarse-graining
Voth, Gregory
2013-03-01
Coarse-grained (CG) models provide a computationally efficient means to study biomolecular and other soft matter processes involving large numbers of atoms correlated over distance scales of many covalent bond lengths and long time scales. Variational methods based on information from simulations of finer-grained (e.g., all-atom) models, for example the multiscale coarse-graining (MS-CG) and relative entropy minimization methods, provide attractive tools for the systematic development of CG models. However, these methods have important drawbacks when used in the ultra coarse-grained'' (UCG) regime, e.g., at a resolution level coarser or much coarser than one amino acid residue per effective CG particle in proteins. This is due to the possible existece of multiple metastable states within'' the CG sites for a given UCG model configuration. In this talk I will describe systematic variational UCG methods specifically designed to CG entire protein domains and subdomains into single effective CG particles. This is accomplished by augmenting existing effective particle CG schemes to allow for discrete state transitions and configuration-dependent resolution. Additionally, certain conclusions of this work connect back to single-state force matching and open up new avenues for method development in that area. These results provide a formal statistical mechanical basis for UCG methods related to force matching and relative entropy CG methods and suggest practical algorithms for constructing optimal approximate UCG models from fine-grained simulation data.
5. Structural effects of an atomic-level layer of water molecules around proteins solvated in supra-molecular coarse-grained water.
PubMed
Riniker, Sereina; Eichenberger, Andreas P; van Gunsteren, Wilfred F
2012-08-01
Atomistic molecular dynamics simulations of proteins in aqueous solution are still limited to the multinanosecond time scale and multinanometer range by computational cost. Combining atomic solutes with a supra-molecular solvent model in hybrid fine-grained/coarse-grained (FG/CG) simulations allows atomic detail in the region of interest while being computationally more efficient. A recent comparison of the properties of four proteins in CG water versus FG water showed the preservation of the secondary and tertiary structure with a computational speed-up of at least an order of magnitude. However, an increased occurrence of hydrogen bonds between side chains was observed due to a lack of hydrogen-bonding partners in the supra-molecular solvent. Here, the introduction of a FG water layer around the protein to recover the hydrogen-bonding pattern of the atomistic simulations is studied. Three layer thicknesses of 0.2, 0.4, and 0.8 nm are considered. A layer thickness of 0.8 nm is found sufficient to recover the behavior of the proteins in the atomistic simulations, whereas the hybrid simulation is still three times more efficient than the atomistic one and the cutoff radius for nonbonded interactions could be increased from 1.4 to 2.0 nm.
6. Aggregation and network formation in self-assembly of protein (H3.1) by a coarse-grained Monte Carlo simulation.
PubMed
Pandey, R B; Farmer, B L
2014-11-01
Multi-scale aggregation to network formation of interacting proteins (H3.1) are examined by a knowledge-based coarse-grained Monte Carlo simulation as a function of temperature and the number of protein chains, i.e., the concentration of the protein. Self-assembly of corresponding homo-polymers of constitutive residues (Cys, Thr, and Glu) with extreme residue-residue interactions, i.e., attractive (Cys-Cys), neutral (Thr-Thr), and repulsive (Glu-Glu), are also studied for comparison with the native protein. Visual inspections show contrast and similarity in morphological evolutions of protein assembly, aggregation of small aggregates to a ramified network from low to high temperature with the aggregation of a Cys-polymer, and an entangled network of Glu and Thr polymers. Variations in mobility profiles of residues with the concentration of the protein suggest that the segmental characteristic of proteins is altered considerably by the self-assembly from that in its isolated state. The global motion of proteins and Cys polymer chains is enhanced by their interacting network at the low temperature where isolated chains remain quasi-static. Transition from globular to random coil transition, evidenced by the sharp variation in the radius of gyration, of an isolated protein is smeared due to self-assembly of interacting networks of many proteins. Scaling of the structure factor S(q) with the wave vector q provides estimates of effective dimension D of the mass distribution at multiple length scales in self-assembly. Crossover from solid aggregates (D ∼ 3) at low temperature to a ramified fibrous network (D ∼ 2) at high temperature is observed for the protein H3.1 and Cys polymers in contrast to little changes in mass distribution (D ∼ 1.6) of fibrous Glu- and Thr-chain configurations.
7. Aggregation and network formation in self-assembly of protein (H3.1) by a coarse-grained Monte Carlo simulation
Pandey, R. B.; Farmer, B. L.
2014-11-01
Multi-scale aggregation to network formation of interacting proteins (H3.1) are examined by a knowledge-based coarse-grained Monte Carlo simulation as a function of temperature and the number of protein chains, i.e., the concentration of the protein. Self-assembly of corresponding homo-polymers of constitutive residues (Cys, Thr, and Glu) with extreme residue-residue interactions, i.e., attractive (Cys-Cys), neutral (Thr-Thr), and repulsive (Glu-Glu), are also studied for comparison with the native protein. Visual inspections show contrast and similarity in morphological evolutions of protein assembly, aggregation of small aggregates to a ramified network from low to high temperature with the aggregation of a Cys-polymer, and an entangled network of Glu and Thr polymers. Variations in mobility profiles of residues with the concentration of the protein suggest that the segmental characteristic of proteins is altered considerably by the self-assembly from that in its isolated state. The global motion of proteins and Cys polymer chains is enhanced by their interacting network at the low temperature where isolated chains remain quasi-static. Transition from globular to random coil transition, evidenced by the sharp variation in the radius of gyration, of an isolated protein is smeared due to self-assembly of interacting networks of many proteins. Scaling of the structure factor S(q) with the wave vector q provides estimates of effective dimension D of the mass distribution at multiple length scales in self-assembly. Crossover from solid aggregates (D ˜ 3) at low temperature to a ramified fibrous network (D ˜ 2) at high temperature is observed for the protein H3.1 and Cys polymers in contrast to little changes in mass distribution (D ˜ 1.6) of fibrous Glu- and Thr-chain configurations.
8. Accurate flexible fitting of high-resolution protein structures to small-angle x-ray scattering data using a coarse-grained model with implicit hydration shell.
PubMed
Zheng, Wenjun; Tekpinar, Mustafa
2011-12-21
Small-angle x-ray scattering (SAXS) is a powerful technique widely used to explore conformational states and transitions of biomolecular assemblies in solution. For accurate model reconstruction from SAXS data, one promising approach is to flexibly fit a known high-resolution protein structure to low-resolution SAXS data by computer simulations. This is a highly challenging task due to low information content in SAXS data. To meet this challenge, we have developed what we believe to be a novel method based on a coarse-grained (one-bead-per-residue) protein representation and a modified form of the elastic network model that allows large-scale conformational changes while maintaining pseudobonds and secondary structures. Our method optimizes a pseudoenergy that combines the modified elastic-network model energy with a SAXS-fitting score and a collision energy that penalizes steric collisions. Our method uses what we consider a new implicit hydration shell model that accounts for the contribution of hydration shell to SAXS data accurately without explicitly adding waters to the system. We have rigorously validated our method using five test cases with simulated SAXS data and three test cases with experimental SAXS data. Our method has successfully generated high-quality structural models with root mean-squared deviation of 1 ∼ 3 Å from the target structures.
9. Asymmetry in structural response of inner and outer transmembrane segments of CorA protein by a coarse-grain model
Kitjaruwankul, Sunan; Khrutto, Channarong; Sompornpisut, Pornthep; Farmer, B. L.; Pandey, R. B.
2016-10-01
Structure of CorA protein and its inner (i.corA) and outer (o.corA) transmembrane (TM) components are investigated as a function of temperature by a coarse-grained Monte Carlo simulation. Thermal response of i.corA is found to differ considerably from that of the outer component, o.corA. Analysis of the radius of gyration reveals that the inner TM component undergoes a continuous transition from a globular conformation to a random coil structure on raising the temperature. In contrast, the outer transmembrane component exhibits an abrupt (nearly discontinuous) thermal response in a narrow range of temperature. Scaling of the structure factor shows a globular structure of i.corA at a low temperature with an effective dimension D ˜ 3 and a random coil at a high temperature with D ˜ 2. The residue distribution in o.corA is slightly sparser than that of i.corA in a narrow thermos-responsive regime. The difference in thermos-response characteristics of these components (i.corA and o.corA) may reflect their unique transmembrane functions.
10. Thermal response of proteins (histone H2AX, H3.1) by a coarse-grained Monte Carlo simulation with a knowledge-based phenomenological potential
Fritsche, Miriam; Heermann, Dieter; Pandey, Ras; Farmer, Barry
2012-02-01
Using a coarse-grained bond fluctuating model, we investigate structure and dynamics of two histones, H2AX (143 residues) and H3.1 (136 residues) as a function of temperature (T). A knowledged based contact matrix is used as an input for a phenomenological residue-residue interaction in a generalized Lennard-Jones potential. Metropolis algorithm is used to execute stochastic movement of each residue. A number of local and global physical quantities are analyzed. Despite unique energy and mobility profiles of its residues in a specific sequence, the histone H3.1 appears to undergo a structural transformation from a random coil to a globular conformation on reducing the temperature. The radius of gyration of the histone H2AX, in contrast, exhibits a non-monotonic dependence on temperature with a maximum at a characteristic temperature (Tc) where crossover occurs from a positive (stretching below Tc) to negative (contraction above Tc) thermal response on increasing T. Multi-scale structures of the proteins are examined by a detailed analysis of their structure functions.
11. Equilibration of complexes of DNA and H-NS proteins on charged surfaces: A coarse-grained model point of view
Joyeux, Marc
2014-09-01
The Histone-like Nucleoid Structuring protein (H-NS) is a nucleoid-associated protein, which is involved in both gene regulation and DNA compaction. Although it is a key player in genome organization by forming bridges between DNA duplexes, the precise structure of complexes of DNA and H-NS proteins is still not well understood. In particular, it is not clear whether the structure of DNA/H-NS complexes in the living cell is similar to that of complexes deposited on mica surfaces, which may be observed by AFM microscopy. A coarse-grained model, which helps getting more insight into this question, is described and analyzed in the present paper. This model is able of describing both the bridging of bacterial DNA by H-NS in the bulk and the deposition and equilibration of the complex on a charged surface. Simulations performed with the model reveal that a slight attraction between DNA and the charged surface is sufficient to let DNA/H-NS complexes reorganize from 3D coils to planar plasmids bridged by H-NS proteins similar to those observed by AFM microscopy. They furthermore highlight the antagonistic effects of the interactions between DNA and the surface. Indeed, increasing these interactions slows down the equilibration of naked plasmids on the surface but, on the other hand, enables a faster equilibration of DNA/H-NS complexes. Based on the distribution of the lifetimes of H-NS bridges and the time evolution of the number of trans-binding protein dimers during equilibration of the complexes on the surface, it is argued that the decrease of the equilibration time of the complex upon increase of the interaction strength between DNA and the surface is ascribable to the associated decrease of the probability to form new bridges between DNA and the proteins.
12. Coarse-Grained Simulations of Topology-Dependent Mechanisms of Protein Unfolding and Translocation Mediated by ClpY ATPase Nanomachines.
PubMed
Kravats, Andrea N; Tonddast-Navaei, Sam; Stan, George
2016-01-01
Clp ATPases are powerful ring shaped nanomachines which participate in the degradation pathway of the protein quality control system, coupling the energy from ATP hydrolysis to threading substrate proteins (SP) through their narrow central pore. Repetitive cycles of sequential intra-ring ATP hydrolysis events induce axial excursions of diaphragm-forming central pore loops that effect the application of mechanical forces onto SPs to promote unfolding and translocation. We perform Langevin dynamics simulations of a coarse-grained model of the ClpY ATPase-SP system to elucidate the molecular details of unfolding and translocation of an α/β model protein. We contrast this mechanism with our previous studies which used an all-α SP. We find conserved aspects of unfolding and translocation mechanisms by allosteric ClpY, including unfolding initiated at the tagged C-terminus and translocation via a power stroke mechanism. Topology-specific aspects include the time scales, the rate limiting steps in the degradation pathway, the effect of force directionality, and the translocase efficacy. Mechanisms of ClpY-assisted unfolding and translocation are distinct from those resulting from non-allosteric mechanical pulling. Bulk unfolding simulations, which mimic Atomic Force Microscopy-type pulling, reveal multiple unfolding pathways initiated at the C-terminus, N-terminus, or simultaneously from both termini. In a non-allosteric ClpY ATPase pore, mechanical pulling with constant velocity yields larger effective forces for SP unfolding, while pulling with constant force results in simultaneous unfolding and translocation. PMID:26734937
13. Coarse-Grained Simulations of Topology-Dependent Mechanisms of Protein Unfolding and Translocation Mediated by ClpY ATPase Nanomachines.
PubMed
Kravats, Andrea N; Tonddast-Navaei, Sam; Stan, George
2016-01-01
Clp ATPases are powerful ring shaped nanomachines which participate in the degradation pathway of the protein quality control system, coupling the energy from ATP hydrolysis to threading substrate proteins (SP) through their narrow central pore. Repetitive cycles of sequential intra-ring ATP hydrolysis events induce axial excursions of diaphragm-forming central pore loops that effect the application of mechanical forces onto SPs to promote unfolding and translocation. We perform Langevin dynamics simulations of a coarse-grained model of the ClpY ATPase-SP system to elucidate the molecular details of unfolding and translocation of an α/β model protein. We contrast this mechanism with our previous studies which used an all-α SP. We find conserved aspects of unfolding and translocation mechanisms by allosteric ClpY, including unfolding initiated at the tagged C-terminus and translocation via a power stroke mechanism. Topology-specific aspects include the time scales, the rate limiting steps in the degradation pathway, the effect of force directionality, and the translocase efficacy. Mechanisms of ClpY-assisted unfolding and translocation are distinct from those resulting from non-allosteric mechanical pulling. Bulk unfolding simulations, which mimic Atomic Force Microscopy-type pulling, reveal multiple unfolding pathways initiated at the C-terminus, N-terminus, or simultaneously from both termini. In a non-allosteric ClpY ATPase pore, mechanical pulling with constant velocity yields larger effective forces for SP unfolding, while pulling with constant force results in simultaneous unfolding and translocation.
14. Coarse-Grained Simulations of Topology-Dependent Mechanisms of Protein Unfolding and Translocation Mediated by ClpY ATPase Nanomachines
PubMed Central
Kravats, Andrea N.; Tonddast-Navaei, Sam; Stan, George
2016-01-01
Clp ATPases are powerful ring shaped nanomachines which participate in the degradation pathway of the protein quality control system, coupling the energy from ATP hydrolysis to threading substrate proteins (SP) through their narrow central pore. Repetitive cycles of sequential intra-ring ATP hydrolysis events induce axial excursions of diaphragm-forming central pore loops that effect the application of mechanical forces onto SPs to promote unfolding and translocation. We perform Langevin dynamics simulations of a coarse-grained model of the ClpY ATPase-SP system to elucidate the molecular details of unfolding and translocation of an α/β model protein. We contrast this mechanism with our previous studies which used an all-α SP. We find conserved aspects of unfolding and translocation mechanisms by allosteric ClpY, including unfolding initiated at the tagged C-terminus and translocation via a power stroke mechanism. Topology-specific aspects include the time scales, the rate limiting steps in the degradation pathway, the effect of force directionality, and the translocase efficacy. Mechanisms of ClpY-assisted unfolding and translocation are distinct from those resulting from non-allosteric mechanical pulling. Bulk unfolding simulations, which mimic Atomic Force Microscopy-type pulling, reveal multiple unfolding pathways initiated at the C-terminus, N-terminus, or simultaneously from both termini. In a non-allosteric ClpY ATPase pore, mechanical pulling with constant velocity yields larger effective forces for SP unfolding, while pulling with constant force results in simultaneous unfolding and translocation. PMID:26734937
15. Systematic Coarse-graining of Molecular Dynamics Simulations
Voth, Gregory
2015-03-01
Coarse-grained (CG) models can provide a computationally efficient means to study biomolecular and other soft matter processes involving large numbers of atoms that are correlated over distance scales of many covalent bond lengths and at long time scales. Systematic variational coarse-graining methods based on information from molecular dynamics simulations of finer-grained (e.g., all-atom) models provide attractive tools for the systematic development of CG models. Examples include the multiscale coarse-graining (MS-CG) and relative entropy minimization methods, and results from the former theory will be presented in this talk. In addition, a new approach will be presented that is appropriate for the ultra coarse-grained'' (UCG) regime, e.g., at a coarse-grained resolution that is much coarser than one amino acid residue per CG particle in a protein. At this level of coarse-graining, one is faced with the possible existence of multiple metastable states within'' the CG sites for a given UCG model configuration. I will therefore describe newer systematic variational UCG methods specifically designed to CG entire protein domains and subdomains into single effective CG particles. This is accomplished by augmenting existing effective particle CG schemes to allow for discrete state transitions and configuration-dependent resolution. Additionally, certain aspects of this work connect back to single-state force matching and open up new avenues for method development. This general body of theory and algorithm provides a formal statistical mechanical basis for the coarse-graining of fine-grained molecular dynamics simulation data at various levels of CG resolution. Representative applications will be described as time allows.
16. Coarse-grained modeling of DNA curvature
Freeman, Gordon S.; Hinckley, Daniel M.; Lequieu, Joshua P.; Whitmer, Jonathan K.; de Pablo, Juan J.
2014-10-01
The interaction of DNA with proteins occurs over a wide range of length scales, and depends critically on its local structure. In particular, recent experimental work suggests that the intrinsic curvature of DNA plays a significant role on its protein-binding properties. In this work, we present a coarse grained model of DNA that is capable of describing base-pairing, hybridization, major and minor groove widths, and local curvature. The model represents an extension of the recently proposed 3SPN.2 description of DNA [D. M. Hinckley, G. S. Freeman, J. K. Whitmer, and J. J. de Pablo, J. Chem. Phys. 139, 144903 (2013)], into which sequence-dependent shape and mechanical properties are incorporated. The proposed model is validated against experimental data including melting temperatures, local flexibilities, dsDNA persistence lengths, and minor groove width profiles.
17. Coarse graining of polystyrene sulfonate
Perahia, Dvora; Agrawal, Anupriya; Grest, Gary S.
2015-03-01
Capturing large length scales in soft matter while retaining atomistic properties is imperative to computational studies. Here we develop a new coarse-grained model for polystyrene sulfonate (PSS) that often serves as a model system because of its narrow molecular weight distribution and defined degree of sulfonation. Four beads are used to represent polymer where the backbone, the phenyl group, and the sulfonated group are each represented by a different bead and the fourth one represents counterion, which is sodium in our case. Initial atomistic simulations of PSS melt with sulfonation levels of 2-10%, with a dielectric constant ɛ = 1 revealed a locked'' phase where motion of the polymer is limited. Dielectric constant of ɛ = 5 was used to accelerate the dynamics. Bonded interactions were obtained using Boltzmann inversion on the bonded distributions extracted from atomistic simulation. Non-bonded interaction of polystyrene monomer was taken from our previous work and potential of mean force was used as the initial guess for interaction of the ionic beads. This set of potential was subsequently iterated to get a good match with radial distribution functions. This potential and its transferability across dielectric constants and temperatures will be presented. Grant DE-SC007908.
18. Coarse-grained model of glycosaminoglycans.
PubMed
Samsonov, Sergey A; Bichmann, Leon; Pisabarro, M Teresa
2015-01-26
Glycosaminoglycans (GAGs) represent a class of anionic periodic linear polysaccharides, which mediate cell communication processes by interactions with their protein targets in the extracellular matrix. Due to their high flexibility, charged nature, periodicity, and polymeric nature, GAGs are challenging systems for computational approaches. To deal with the length challenge, coarse-grained (CG) modeling could be a promising approach. In this work, we develop AMBER-compatible CG parameters for GAGs using all-atomic (AA) molecular dynamics (MD) simulations in explicit solvent and the Boltzmann conversion approach. We compare both global and local properties of GAGs obtained in the simulations with AA and CG approaches, and we conclude that our CG model is appropriate for the MD approach of long GAG molecules at long time scales.
19. Coarse-grained computer simulation of dynamics in thylakoid membranes: methods and opportunities
PubMed Central
Schneider, Anna R.; Geissler, Phillip L.
2013-01-01
Coarse-grained simulation is a powerful and well-established suite of computational methods for studying structure and dynamics in nanoscale biophysical systems. As our understanding of the plant photosynthetic apparatus has become increasingly nuanced, opportunities have arisen for coarse-grained simulation to complement experiment by testing hypotheses and making predictions. Here, we give an overview of best practices in coarse-grained simulation, with a focus on techniques and results that are applicable to the plant thylakoid membrane–protein system. We also discuss current research topics for which coarse-grained simulation has the potential to play a key role in advancing the field. PMID:24478781
20. Quasiclassical coarse graining and thermodynamic entropy
SciTech Connect
Gell-Mann, Murray; Hartle, James B.
2007-08-15
Our everyday descriptions of the universe are highly coarse grained, following only a tiny fraction of the variables necessary for a perfectly fine-grained description. Coarse graining in classical physics is made natural by our limited powers of observation and computation. But in the modern quantum mechanics of closed systems, some measure of coarse graining is inescapable because there are no nontrivial, probabilistic, fine-grained descriptions. This essay explores the consequences of that fact. Quantum theory allows for various coarse-grained descriptions, some of which are mutually incompatible. For most purposes, however, we are interested in the small subset of 'quasiclassical descriptions' defined by ranges of values of averages over small volumes of densities of conserved quantities such as energy and momentum and approximately conserved quantities such as baryon number. The near-conservation of these quasiclassical quantities results in approximate decoherence, predictability, and local equilibrium, leading to closed sets of equations of motion. In any description, information is sacrificed through the coarse graining that yields decoherence and gives rise to probabilities for histories. In quasiclassical descriptions, further information is sacrificed in exhibiting the emergent regularities summarized by classical equations of motion. An appropriate entropy measures the loss of information. For a 'quasiclassical realm' this is connected with the usual thermodynamic entropy as obtained from statistical mechanics. It was low for the initial state of our universe and has been increasing since.
1. Parameterization of backbone flexibility in a coarse-grained force field for proteins (COFFDROP) derived from all-atom explicit-solvent molecular dynamics simulations of all possible two-residue peptides
PubMed Central
Frembgen-Kesner, Tamara; Andrews, Casey T.; Li, Shuxiang; Ngo, Nguyet Anh; Shubert, Scott A.; Jain, Aakash; Olayiwola, Oluwatoni; Weishaar, Mitch R.; Elcock, Adrian H.
2015-01-01
Recently, we reported the parameterization of a set of coarse-grained (CG) nonbonded potential functions, derived from all-atom explicit-solvent molecular dynamics (MD) simulations of amino acid pairs, and designed for use in (implicit-solvent) Brownian dynamics (BD) simulations of proteins; this force field was named COFFDROP (COarse-grained Force Field for Dynamic Representations Of Proteins). Here, we describe the extension of COFFDROP to include bonded backbone terms derived from fitting to results of explicit-solvent MD simulations of all possible two-residue peptides containing the 20 standard amino acids, with histidine modeled in both its protonated and neutral forms. The iterative Boltzmann inversion (IBI) method was used to optimize new CG potential functions for backbone-related terms by attempting to reproduce angle, dihedral and distance probability distributions generated by the MD simulations. In a simple test of the transferability of the extended force field, the angle, dihedral and distance probability distributions obtained from BD simulations of 56 three-residue peptides were compared to results from corresponding explicit-solvent MD simulations. In a more challenging test of the COFFDROP force field, it was used to simulate eight intrinsically disordered proteins and was shown to quite accurately reproduce the experimental hydrodynamic radii (Rhydro), provided that the favorable nonbonded interactions of the force field were uniformly scaled downwards in magnitude. Overall, the results indicate that the COFFDROP force field is likely to find use in modeling the conformational behavior of intrinsically disordered proteins and multi-domain proteins connected by flexible linkers. PMID:26574429
2. Molecular Dynamics Trajectory Compression with a Coarse-Grained Model
PubMed Central
Cheng, Yi-Ming; Gopal, Srinivasa Murthy; Law, Sean M.; Feig, Michael
2012-01-01
Molecular dynamics trajectories are very data-intensive thereby limiting sharing and archival of such data. One possible solution is compression of trajectory data. Here, trajectory compression based on conversion to the coarse-grained model PRIMO is proposed. The compressed data is about one third of the original data and fast decompression is possible with an analytical reconstruction procedure from PRIMO to all-atom representations. This protocol largely preserves structural features and to a more limited extent also energetic features of the original trajectory. PMID:22025759
3. Coarse-grained Simulations of Viral Assembly
2011-12-01
The formation of viral capsids is a marvel of natural engineering and design. A large number (from 60 to thousands) of protein subunits assemble into complete, reproducible structures under a variety of conditions while avoiding kinetic and thermodynamic traps. Small single-stranded RNA viruses not only assemble their coat proteins in this fashion but also package their genome during the self-assembly process. Recent experiments have shown that the coat proteins are competent to assemble not merely around their own genomes but heterologous RNA, synthetic polyanions and even functionalized gold nanoparticles. Remarkably these viruses can even assemble around cargo not commensurate with their native state by adopting different morphologies. Understanding the properties that confer such exquisite precision and flexibility to the assembly process could aid biomedical research in the search for novel antiviral remedies, drug-delivery vehicles and contrast agents used in bioimaging. At the same time, viral assembly provides an excellent model system for the development of a statistical mechanical understanding of biological self-assembly, in the hopes of that we will identify some universal principles that underly such processes. This work consists of computational studies using coarse-grained representations of viral coat proteins and their cargoes. We find the relative strength of protein-cargo and protein-protein interactions has a profound effect on the assembly pathway, in some cases leading to assembly mechanisms that are markedly different from those found in previous work on the assembly of empty capsids. In the case of polymeric cargo, we find the first evidence for a previously theorized mechanism in which the polymer actively participates in recruiting free subunits to the assembly process through cooperative polymer-protein motions. We find that successful assembly is non-monotonic in protein-cargo affinity, such affinity can be detrimental to assembly if it
4. Coarse-Grained Model of SNARE-Mediated Docking
PubMed Central
Fortoul, Nicole; Singh, Pankaj; Hui, Chung-Yuen; Bykhovskaia, Maria; Jagota, Anand
2015-01-01
Synaptic transmission requires that vesicles filled with neurotransmitter molecules be docked to the plasma membrane by the SNARE protein complex. The SNARE complex applies attractive forces to overcome the long-range repulsion between the vesicle and membrane. To understand how the balance between the attractive and repulsive forces defines the equilibrium docked state we have developed a model that combines the mechanics of vesicle/membrane deformation with an apparently new coarse-grained model of the SNARE complex. The coarse-grained model of the SNARE complex is calibrated by comparison with all-atom molecular dynamics simulations as well as by force measurements in laser tweezer experiments. The model for vesicle/membrane interactions includes the forces produced by membrane deformation and hydration or electrostatic repulsion. Combining these two parts, the coarse-grained model of the SNARE complex with membrane mechanics, we study how the equilibrium docked state varies with the number of SNARE complexes. We find that a single SNARE complex is able to bring a typical synaptic vesicle to within a distance of ∼3 nm from the membrane. Further addition of SNARE complexes shortens this distance, but an overdocked state of >4–6 SNAREs actually increases the equilibrium distance. PMID:25954883
5. Deriving Coarse-Grained Charges from All-Atom Systems: An Analytic Solution.
PubMed
McCullagh, Peter; Lake, Peter T; McCullagh, Martin
2016-09-13
An analytic method to assign optimal coarse-grained charges based on electrostatic potential matching is presented. This solution is the infinite size and density limit of grid-integration charge-fitting and is computationally more efficient by several orders of magnitude. The solution is also minimized with respect to coarse-grained positions which proves to be an extremely important step in reproducing the all-atom electrostatic potential. The joint optimal-charge optimal-position coarse-graining procedure is applied to a number of aggregating proteins using single-site per amino acid resolution. These models provide a good estimate of both the vacuum and Debye-Hückel screened all-atom electrostatic potentials in the vicinity and in the far-field of the protein. Additionally, these coarse-grained models are shown to approximate the all-atom dimerization electrostatic potential energy of 10 aggregating proteins with good accuracy.
6. Measuring Crack Length in Coarse Grain Ceramics
NASA Technical Reports Server (NTRS)
Salem, Jonathan A.; Ghosn, Louis J.
2010-01-01
Due to a coarse grain structure, crack lengths in precracked spinel specimens could not be measured optically, so the crack lengths and fracture toughness were estimated by strain gage measurements. An expression was developed via finite element analysis to correlate the measured strain with crack length in four-point flexure. The fracture toughness estimated by the strain gaged samples and another standardized method were in agreement.
7. The power of coarse graining in biomolecular simulations
PubMed Central
Ingólfsson, Helgi I; Lopez, Cesar A; Uusitalo, Jaakko J; de Jong, Djurre H; Gopal, Srinivasa M; Periole, Xavier; Marrink, Siewert J
2014-01-01
Computational modeling of biological systems is challenging because of the multitude of spatial and temporal scales involved. Replacing atomistic detail with lower resolution, coarse grained (CG), beads has opened the way to simulate large-scale biomolecular processes on time scales inaccessible to all-atom models. We provide an overview of some of the more popular CG models used in biomolecular applications to date, focusing on models that retain chemical specificity. A few state-of-the-art examples of protein folding, membrane protein gating and self-assembly, DNA hybridization, and modeling of carbohydrate fibers are used to illustrate the power and diversity of current CG modeling. PMID:25309628
8. Implementation of molecular dynamics and its extensions with the coarse-grained UNRES force field on massively parallel systems; towards millisecond-scale simulations of protein structure, dynamics, and thermodynamics.
PubMed
Liwo, Adam; Ołdziej, Stanisław; Czaplewski, Cezary; Kleinerman, Dana S; Blood, Philip; Scheraga, Harold A
2010-03-01
We report the implementation of our united-residue UNRES force field for simulations of protein structure and dynamics with massively parallel architectures. In addition to coarse-grained parallelism already implemented in our previous work, in which each conformation was treated by a different task, we introduce a fine-grained level in which energy and gradient evaluation are split between several tasks. The Message Passing Interface (MPI) libraries have been utilized to construct the parallel code. The parallel performance of the code has been tested on a professional Beowulf cluster (Xeon Quad Core), a Cray XT3 supercomputer, and two IBM BlueGene/P supercomputers with canonical and replica-exchange molecular dynamics. With IBM BlueGene/P, about 50 % efficiency and 120-fold speed-up of the fine-grained part was achieved for a single trajectory of a 767-residue protein with use of 256 processors/trajectory. Because of averaging over the fast degrees of freedom, UNRES provides an effective 1000-fold speed-up compared to the experimental time scale and, therefore, enables us to effectively carry out millisecond-scale simulations of proteins with 500 and more amino-acid residues in days of wall-clock time.
9. Structural classification of steroid-binding sites on proteins by coarse-grained atomic environment and its correlation with their biological function.
PubMed
Hori-Tanaka, Yasuha; Yura, Kei; Takai-Igarashi, Takako; Tanaka, Hiroshi
2015-04-01
Steroid hormone is extensively used for transmitting variety of biological signals in organisms. Natural steroid hormone is synthesized from cholesterol in adrenal cortex and in sexual gland in vertebrates. Appropriately dosed synthetic steroid hormones can be used for medication. Despite their positive effects as medicine, they sometimes cause significant side effects due to their wide range of actions, and the studies for discovering the mechanisms of side effects were carried out aiming to reduce the side effects. The fundamental cause of the side effects seems to be interactions between the steroid and a non-target protein. To understand the possible range of interaction of steroid molecule, we gathered all the three-dimensional structures of protein-steroid complex determined by X-ray crystallography, compared the atomic environments of the steroid-binding sites in proteins and classified the pattern of steroid binding. Protein Data Bank contained 871 structures of steroid-protein complexes in 382 entries. For this study, we selected 832 steroid binding proteins. Using a newly developed method to describe the atomic environments of these steroid molecules and their function, we were able to separate the environments into six patterns. This classification had a potential to predict the function of function-unknown proteins with a co-crystallized steroid molecule. We speculated that the proteins grouped into the same pattern of nuclear receptors were the candidates of non-targeted proteins causing a side effect by a therapeutic prescription of steroid hormone.
10. Equilibrium behavior of coarse-grained chaos
Egolf, David A.; Ballard, Christopher C.; Esty, C. Clark
2015-03-01
A wide variety of systems exhibiting spatiotemporal chaos have been shown to be extensive, in that their fractal dimensions grow linearly with volume. Ruelle argued that this extensivity is evidence that these systems can be viewed as a gas of weakly-interacting regions. We have tested this idea by performing large-scale computational studies of spatiotemporal chaos in the 1D complex Ginzburg-Landau equation, and we have found that aspects of the coarse-grained system are well-described not only as a gas, but as an equilibrium gas -- in particular, a Tonks gas (and variants) in the grand canonical ensemble. Furthermore, for small system sizes, the average number of particles in the corresponding Tonks gas exhibits oscillatory, decaying deviations from extensivity in agreement with deviations in the fractal dimension found by Fishman and Egolf. This result not only supports Ruelle's picture but also suggests that the coarse-grained behavior of this far-from-equilibrium system might be understood using equilibrium statistical mechanics.
11. Multiresolution Modeling of Polymer Solutions: Wavelet-Based Coarse-Graining and Reverse-Mapping
Ismail, Ahmed; Adorf, Carl Simon; Agarwal, Animesh; Iacovella, Christopher R.
2014-03-01
Unlike multiscale methods, which encompass multiple simulation techniques, multiresolution models uses one modeling technique at different length and time scales. We present a combined coarse-graining and reverse-mapping framework for modeling of semidilute polymer solutions, based on the wavelet-accelerated Monte Carlo (WAMC) method, which forms a hierarchy of resolutions to model polymers at length scales that cannot be reached via atomistic or even standard'' coarse-grained simulations. A universal scaling function is obtained so that potentials do not need to be recomputed as the scale of the system is changed. We show that coarse-grained polymer solutions can reproduce results obtained from the simulations of the more detailed atomistic system to a reasonable degree of accuracy. Reverse mapping proceeds similarly: using probability distributions obtained from coarse-graining the bond lengths, angles, torsions, and the non-bonded potentials, we can reconstruct a more detailed polymer consistent with both geometric constraints and energetic considerations. Using a convergence factor'' within a Monte Carlo-based energy optimization scheme, we can successfully reconstruct entire atomistic configurations from coarse-grained descriptions.
12. A coarse-grained model of microtubule self-assembly
Regmi, Chola; Cheng, Shengfeng
Microtubules play critical roles in cell structures and functions. They also serve as a model system to stimulate the next-generation smart, dynamic materials. A deep understanding of their self-assembly process and biomechanical properties will not only help elucidate how microtubules perform biological functions, but also lead to exciting insight on how microtubule dynamics can be altered or even controlled for specific purposes such as suppressing the division of cancer cells. Combining all-atom molecular dynamics (MD) simulations and the essential dynamics coarse-graining method, we construct a coarse-grained (CG) model of the tubulin protein, which is the building block of microtubules. In the CG model a tubulin dimer is represented as an elastic network of CG sites, the locations of which are determined by examining the protein dynamics of the tubulin and identifying the essential dynamic domains. Atomistic MD modeling is employed to directly compute the tubulin bond energies in the surface lattice of a microtubule, which are used to parameterize the interactions between CG building blocks. The CG model is then used to study the self-assembly pathways, kinetics, dynamics, and nanomechanics of microtubules.
13. Glasses in coarse-grained micrometeorites
Varela, M. E.; Kurat, G.
2009-06-01
Micrometeorites (MMs, interplanetary dust particles with 25 - 500 μm diameters) carry the main mass of extraterrestrial matter that is captured by Earth. The coarse-grained MMs mainly consist of olivine aggregates, which - as their counterparts in CC chondrites - also contain pyroxenes and glass. We studied clear glasses in four coarse-grained crystalline MMs (10M12, M92-6b, AM9, and Mc7-10), which were collected from the ice at Cap Prudhomme, Antarctica. Previous studies of glasses (e.g., glass inclusions trapped in olivine and clear mesostasis glass) in carbonaceous and ordinary chondrites showed that these phases could keep memory of the physical-chemical conditions to which extraterrestrial matter was exposed. Here we compare the chemical compositions of MM glasses and glasses from CM chondrites with that in experimentally heated objects from the Allende CV chondrite and with glasses from cometary particles. Our results show that MMs were heated to variable degrees (during entry through the terrestrial atmosphere), which caused a range from very little chemical modification of the glass to total melting of the precursor object. Such modifications include dissolution of minerals in the melted glass precursor and some loss of volatile alkali elements. The chemical composition of all precursor glasses in the MMs investigated is not primitive such as glasses in CM and CR chondrite objects. It shows signs of pre-terrestrial chemical modification, e.g., metasomatic enrichments in Na and Fe 2+ presumably in the solar nebula. Glasses of MMs heated to very low degree have a chemical composition indistinguishable from that of glasses in comet Wild 2 particles; giving additional evidence that interplanetary dust (e.g., Antarctic MMs) possibly represents samples from comets.
14. Simulating the Entropic Collapse of Coarse-Grained Chromosomes
PubMed Central
Shendruk, Tyler N.; Bertrand, Martin; de Haan, Hendrick W.; Harden, James L.; Slater, Gary W.
2015-01-01
Depletion forces play a role in the compaction and decompaction of chromosomal material in simple cells, but it has remained debatable whether they are sufficient to account for chromosomal collapse. We present coarse-grained molecular dynamics simulations, which reveal that depletion-induced attraction is sufficient to cause the collapse of a flexible chain of large structural monomers immersed in a bath of smaller depletants. These simulations use an explicit coarse-grained computational model that treats both the supercoiled DNA structural monomers and the smaller protein crowding agents as combinatorial, truncated Lennard-Jones spheres. By presenting a simple theoretical model, we quantitatively cast the action of depletants on supercoiled bacterial DNA as an effective solvent quality. The rapid collapse of the simulated flexible chromosome at the predicted volume fraction of depletants is a continuous phase transition. Additional physical effects to such simple chromosome models, such as enthalpic interactions between structural monomers or chain rigidity, are required if the collapse is to be a first-order phase transition. PMID:25692586
15. Simulating the entropic collapse of coarse-grained chromosomes.
PubMed
Shendruk, Tyler N; Bertrand, Martin; de Haan, Hendrick W; Harden, James L; Slater, Gary W
2015-02-17
Depletion forces play a role in the compaction and decompaction of chromosomal material in simple cells, but it has remained debatable whether they are sufficient to account for chromosomal collapse. We present coarse-grained molecular dynamics simulations, which reveal that depletion-induced attraction is sufficient to cause the collapse of a flexible chain of large structural monomers immersed in a bath of smaller depletants. These simulations use an explicit coarse-grained computational model that treats both the supercoiled DNA structural monomers and the smaller protein crowding agents as combinatorial, truncated Lennard-Jones spheres. By presenting a simple theoretical model, we quantitatively cast the action of depletants on supercoiled bacterial DNA as an effective solvent quality. The rapid collapse of the simulated flexible chromosome at the predicted volume fraction of depletants is a continuous phase transition. Additional physical effects to such simple chromosome models, such as enthalpic interactions between structural monomers or chain rigidity, are required if the collapse is to be a first-order phase transition. PMID:25692586
16. Bridging between NMA and Elastic Network Models: Preserving All-Atom Accuracy in Coarse-Grained Models
PubMed Central
Na, Hyuntae; Jernigan, Robert L.; Song, Guang
2015-01-01
Dynamics can provide deep insights into the functional mechanisms of proteins and protein complexes. For large protein complexes such as GroEL/GroES with more than 8,000 residues, obtaining a fine-grained all-atom description of its normal mode motions can be computationally prohibitive and is often unnecessary. For this reason, coarse-grained models have been used successfully. However, most existing coarse-grained models use extremely simple potentials to represent the interactions within the coarse-grained structures and as a result, the dynamics obtained for the coarse-grained structures may not always be fully realistic. There is a gap between the quality of the dynamics of the coarse-grained structures given by all-atom models and that by coarse-grained models. In this work, we resolve an important question in protein dynamics computations—how can we efficiently construct coarse-grained models whose description of the dynamics of the coarse-grained structures remains as accurate as that given by all-atom models? Our method takes advantage of the sparseness of the Hessian matrix and achieves a high efficiency with a novel iterative matrix projection approach. The result is highly significant since it can provide descriptions of normal mode motions at an all-atom level of accuracy even for the largest biomolecular complexes. The application of our method to GroEL/GroES offers new insights into the mechanism of this biologically important chaperonin, such as that the conformational transitions of this protein complex in its functional cycle are even more strongly connected to the first few lowest frequency modes than with other coarse-grained models. PMID:26473491
17. Bridging between NMA and Elastic Network Models: Preserving All-Atom Accuracy in Coarse-Grained Models.
PubMed
Na, Hyuntae; Jernigan, Robert L; Song, Guang
2015-10-01
Dynamics can provide deep insights into the functional mechanisms of proteins and protein complexes. For large protein complexes such as GroEL/GroES with more than 8,000 residues, obtaining a fine-grained all-atom description of its normal mode motions can be computationally prohibitive and is often unnecessary. For this reason, coarse-grained models have been used successfully. However, most existing coarse-grained models use extremely simple potentials to represent the interactions within the coarse-grained structures and as a result, the dynamics obtained for the coarse-grained structures may not always be fully realistic. There is a gap between the quality of the dynamics of the coarse-grained structures given by all-atom models and that by coarse-grained models. In this work, we resolve an important question in protein dynamics computations--how can we efficiently construct coarse-grained models whose description of the dynamics of the coarse-grained structures remains as accurate as that given by all-atom models? Our method takes advantage of the sparseness of the Hessian matrix and achieves a high efficiency with a novel iterative matrix projection approach. The result is highly significant since it can provide descriptions of normal mode motions at an all-atom level of accuracy even for the largest biomolecular complexes. The application of our method to GroEL/GroES offers new insights into the mechanism of this biologically important chaperonin, such as that the conformational transitions of this protein complex in its functional cycle are even more strongly connected to the first few lowest frequency modes than with other coarse-grained models.
18. Biomembranes in atomistic and coarse-grained simulations
Pluhackova, Kristyna; Böckmann, Rainer A.
2015-08-01
The architecture of biological membranes is tightly coupled to the localization, organization, and function of membrane proteins. The organelle-specific distribution of lipids allows for the formation of functional microdomains (also called rafts) that facilitate the segregation and aggregation of membrane proteins and thus shape their function. Molecular dynamics simulations enable to directly access the formation, structure, and dynamics of membrane microdomains at the molecular scale and the specific interactions among lipids and proteins on timescales from picoseconds to microseconds. This review focuses on the latest developments of biomembrane force fields for both atomistic and coarse-grained molecular dynamics (MD) simulations, and the different levels of coarsening of biomolecular structures. It also briefly introduces scale-bridging methods applicable to biomembrane studies, and highlights selected recent applications.
19. Molecular modeling of the binding modes of the Iron-sulfur protein to the Jac1 co-chaperone from Saccharomyces cerevisiae by all-atom and coarse-grained approaches
PubMed Central
Mozolewska, Magdalena A.; Krupa, Paweł; Scheraga, Harold A.; Liwo, Adam
2015-01-01
The Iron sulfur protein 1 (Isu1) from yeast, and the J-type co-chaperone Jac1, are part of a huge ATP-dependent system, and both interact with Hsp70 chaperones. Interaction of Isu1 and Jac1 is a part of the iron-sulfur cluster biogenesis system in mitochondria. In this study, the structure and dynamics of the yeast Isu1-Jac1 complex has been modeled. First, the complete structure of Isu1 was obtained by homology modeling using the I-TASSER server and YASARA software and thereafter tested for stability in the all-atom force field AMBER. Then, the known experimental structure of Jac1 was adopted to obtain initial models of the Isu1-Jac1 complex by using the ZDOCK server for global and local docking and the AutoDock software for local docking. Three most probable models were subsequently subjected to the coarse-grained molecular dynamics simulations with the UNRES force field to obtain the final structures of the complex. In the most probable model, Isu1 binds to the left face of the “Γ” shaped Jac1 molecule by the β-sheet section of Isu1. Residues L105, L109, and Y163 of Jac1 have been assessed by mutation studies to be essential for binding (Ciesielski et al., J. Mol. Biol. 2012, 417, 1–12). These residues were also found, by UNRES/MD simulations, to be involved in strong interactions between Isu1 and Jac1 in the complex. Moreover, N95, T98, P102, H112, V159, L167 and A170 of Jac1, not yet tested experimentally, were also found important in binding. PMID:25973573
20. Molecular modeling of the binding modes of the iron-sulfur protein to the Jac1 co-chaperone from Saccharomyces cerevisiae by all-atom and coarse-grained approaches.
PubMed
Mozolewska, Magdalena A; Krupa, Paweł; Scheraga, Harold A; Liwo, Adam
2015-08-01
The iron-sulfur protein 1 (Isu1) and the J-type co-chaperone Jac1 from yeast are part of a huge ATP-dependent system, and both interact with Hsp70 chaperones. Interaction of Isu1 and Jac1 is a part of the iron-sulfur cluster biogenesis system in mitochondria. In this study, the structure and dynamics of the yeast Isu1-Jac1 complex has been modeled. First, the complete structure of Isu1 was obtained by homology modeling using the I-TASSER server and YASARA software and thereafter tested for stability in the all-atom force field AMBER. Then, the known experimental structure of Jac1 was adopted to obtain initial models of the Isu1-Jac1 complex by using the ZDOCK server for global and local docking and the AutoDock software for local docking. Three most probable models were subsequently subjected to the coarse-grained molecular dynamics simulations with the UNRES force field to obtain the final structures of the complex. In the most probable model, Isu1 binds to the left face of the Γ-shaped Jac1 molecule by the β-sheet section of Isu1. Residues L105 , L109 , and Y163 of Jac1 have been assessed by mutation studies to be essential for binding (Ciesielski et al., J Mol Biol 2012; 417:1-12). These residues were also found, by UNRES/molecular dynamics simulations, to be involved in strong interactions between Isu1 and Jac1 in the complex. Moreover, N(95), T(98), P(102), H(112), V(159), L(167), and A(170) of Jac1, not yet tested experimentally, were also found to be important in binding.
1. Investigating the impact of representation upon coarse-grained models
Foley, Thomas; Shell, M. Scott; Noid, William
The first step in building a coarse-grained (CG) model is choosing a representation or mapping' of the original system at a reduced resolution. In practice, the mapping is often chosen on the basis of physical intuition.' Consequently this crucial step would greatly benefit from the development of systematic and principled methodologies. Accordingly, we have studied the relationship between the mapping and the resulting CG model. As a starting point, we have analytically derived, as a function of the CG mapping, the exact many-body potential of mean force (PMF) for the simple Gaussian Network Model (GNM) of protein fluctuations. We use this as a simple model for investigating the effect of the CG mapping upon the information loss and quality of the CG model. Moreover, by considering the GNM's for different proteins, we investigate the significance of high resolution structural features for the quality of the CG model. We acknowledge support from the NSF, Alfred P. Sloan Foundation, and KITP.
2. A coarse-grained spectral signature generator
Lam, K. P.; Austin, J. C.; Day, C. R.
2007-01-01
This paper investigates the method for object fingerprinting in the context of element specific x-ray imaging. In particular, the use of spectral descriptors that are illumination invariant and viewpoint independent for pattern identification was examined in some detail. To improve generating the relevant "signature", the spectral descriptor constructed is enhanced with a differentiator which has built-in noise filtration capability and good localisation properties, thus facilitating the extraction of element specific features at a coarse-grained level. In addition to the demonstrable efficacy in identifying significant image intensity transitions that are associated with the underlying physical process of interest, the method has the distinct advantage of being conceptually simple and computationally efficient. These latter properties allow the descriptor to be further utilised by an intelligent system capable of performing a fine-grained analysis of the extracted pattern signatures. The performance of the spectral descriptor has been studied in terms of the quality of the signature vectors that it generated, quantitatively based on the established framework of Spectral Information Measure (SIM). Early results suggested that such a multiscale approach of image sequence analysis offers a considerable potential for real-time applications.
3. Coarse-grained models for biological simulations
Wu, Zhe; Cui, Qiang; Yethiraj, Arun
2011-03-01
The large timescales and length-scales of interest in biophysics preclude atomistic study of many systems and processes. One appealing approach is to use coarse-grained (CG) models where several atoms are grouped into a single CG site. In this work we describe a new CG force field for lipids, surfactants, and amino acids. The topology of CG sites is the same as in the MARTINI force field, but the new model is compatible with a recently developed CG electrostatic water (Big Multiple Water, BMW) model. The model not only gives correct structural, elastic properties and phase behavior for lipid and surfactants, but also reproduces electrostatic properties at water-membrane interface that agree with experiment and atomistic simulations, including the potential of mean force for charged amino acid residuals at membrane. Consequently, the model predicts stable attachment of cationic peptides (i.e., poly-Arg) on lipid bilayer surface, which is not shown in previous models with non-electrostatic water.
4. Resolution-Adapted All-Atomic and Coarse-Grained Model for Biomolecular Simulations.
PubMed
Shen, Lin; Hu, Hao
2014-06-10
We develop here an adaptive multiresolution method for the simulation of complex heterogeneous systems such as the protein molecules. The target molecular system is described with the atomistic structure while maintaining concurrently a mapping to the coarse-grained models. The theoretical model, or force field, used to describe the interactions between two sites is automatically adjusted in the simulation processes according to the interaction distance/strength. Therefore, all-atomic, coarse-grained, or mixed all-atomic and coarse-grained models would be used together to describe the interactions between a group of atoms and its surroundings. Because the choice of theory is made on the force field level while the sampling is always carried out in the atomic space, the new adaptive method preserves naturally the atomic structure and thermodynamic properties of the entire system throughout the simulation processes. The new method will be very useful in many biomolecular simulations where atomistic details are critically needed.
5. An implicit solvent coarse-grained lipid model with correct stress profile
2010-05-01
We develop a coarse-grained parametrization strategy for lipid membranes that we illustrate for a dipalmitoylphosphatidylcholine bilayer. Our coarse-graining approach eliminates the high cost of explicit solvent but maintains more lipid interaction sites. We use a broad attractive tail-tail potential and extract realistic bonded potentials of mean force from all-atom simulations, resulting in a model with a sharp gel to fluid transition, a correct bending modulus, and overall very reasonable dynamics when compared with experiment. We also determine a quantitative stress profile and correct breakdown of contributions from lipid components when compared with detailed all-atom simulation benchmarks, which has been difficult to achieve for implicit membrane models. Such a coarse-grained lipid model will be necessary for efficiently simulating complex constructs of the membrane, such as protein assembly and lipid raft formation, within these nonaqueous chemical environments.
6. Mesoscopic coarse-grained simulations of lysozyme adsorption.
PubMed
Yu, Gaobo; Liu, Jie; Zhou, Jian
2014-05-01
Coarse-grained simulations are adopted to study the adsorption behavior of lysozyme on different (hydrophobic, neutral hydrophilic, zwitterionic, negatively charged, and positively charged) surfaces at the mesoscopic microsecond time scale (1.2 μs). Simulation results indicate the following: (i) the conformation change of lysozyme on the hydrophobic surface is bigger than any other studied surfaces; (ii) the active sites of lysozyme are faced to the hydrophobic surface with a "top end-on" orientation, while they are exposed to the liquid phase on the hydrophilic surface with a "back-on" orientation; (iii) the neutral hydrophilic surface can induce the adsorption of lysozyme, while the nonspecific protein adsorption can be resisted by the zwitterionic surface; (iv) when the solution ionic strength is low, lysozyme can anchor on the negatively charged surface easily but cannot adsorb on the positively charged surface; (v) when the solution ionic strength is high, the positively charged lysozyme can also adsorb on the like-charged surface; (vi) the major positive potential center of lysozyme, especially the residue ARG128, plays a vital role in leading the adsorption of lysozyme on charged surfaces; (vii) when the ionic strength is high, a counterion layer is formed above the positively charged surface, which is the key factor why lysozyme can adsorb on a like-charged surface. The coarse-grained method based on the MARTINI force field for proteins and the BMW water model could provide an efficient way to understand protein interfacial adsorption behavior at a greater length scale and time scale. PMID:24785197
7. Coarse grained modeling of transport properties in monoclonal antibody solution
Swan, James; Wang, Gang
Monoclonal antibodies and their derivatives represent the fastest growing segment of the bio pharmaceutical industry. For many applications such as novel cancer therapies, high concentration, sub-cutaneous injections of these protein solutions are desired. However, depending on the peptide sequence within the antibody, such high concentration formulations can be too viscous to inject via human derived force alone. Understanding how heterogenous charge distribution and hydrophobicity within the antibodies leads to high viscosities is crucial to their future application. In this talk, we explore a coarse grained computational model of therapeutically relevant monoclonal antibodies that accounts for electrostatic, dispersion and hydrodynamic interactions between suspended antibodies to predict assembly and transport properties in concentrated antibody solutions. We explain the high viscosities observed in many experimental studies of the same biologics.
8. Adaptive coarse graining, environment, strong decoherence, and quasiclassical realms
Gell-Mann, Murray; Hartle, James B.
2014-05-01
Three ideas are introduced that when brought together characterize the realistic quasiclassical realms of our quantum universe as particular kinds of sets of alternative coarse-grained histories defined by quasiclassical variables: (i) branch-dependent adaptive coarse grainings that can be close to maximally refined and can simplify calculation, (ii) narrative coarse grainings that describe how features of the universe change over time and allow the construction of an environment, and (iii) a notion of strong decoherence that characterizes realistic mechanisms of decoherence.
9. Coarse-grained mechanics of viral shells
Klug, William S.; Gibbons, Melissa M.
2008-03-01
We present an approach for creating three-dimensional finite element models of viral capsids from atomic-level structural data (X-ray or cryo-EM). The models capture heterogeneous geometric features and are used in conjunction with three-dimensional nonlinear continuum elasticity to simulate nanoindentation experiments as performed using atomic force microscopy. The method is extremely flexible; able to capture varying levels of detail in the three-dimensional structure. Nanoindentation simulations are presented for several viruses: Hepatitis B, CCMV, HK97, and φ29. In addition to purely continuum elastic models a multiscale technique is developed that combines finite-element kinematics with MD energetics such that large-scale deformations are facilitated by a reduction in degrees of freedom. Simulations of these capsid deformation experiments provide a testing ground for the techniques, as well as insight into the strength-determining mechanisms of capsid deformation. These methods can be extended as a framework for modeling other proteins and macromolecular structures in cell biology.
10. Entrainment of coarse grains using a discrete particle model
SciTech Connect
Valyrakis, Manousos; Arnold, Roger B. Jr.
2014-10-06
Conventional bedload transport models and incipient motion theories relying on a time-averaged boundary shear stress are incapable of accounting for the effects of fluctuating near-bed velocity in turbulent flow and are therefore prone to significant errors. Impulse, the product of an instantaneous force magnitude and its duration, has been recently proposed as an appropriate criterion for quantifying the effects of flow turbulence in removing coarse grains from the bed surface. Here, a discrete particle model (DPM) is used to examine the effects of impulse, representing a single idealized turbulent event, on particle entrainment. The results are classified according to the degree of grain movement into the following categories: motion prior to entrainment, initial dislodgement, and energetic displacement. The results indicate that in all three cases the degree of particle motion depends on both the force magnitude and the duration of its application and suggest that the effects of turbulence must be adequately accounted for in order to develop a more accurate method of determining incipient motion. DPM is capable of simulating the dynamics of grain entrainment and is an appropriate tool for further study of the fundamental mechanisms of sediment transport.
11. Spectral coarse graining for random walks in bipartite networks
Wang, Yang; Zeng, An; Di, Zengru; Fan, Ying
2013-03-01
Many real-world networks display a natural bipartite structure, yet analyzing and visualizing large bipartite networks is one of the open challenges in complex network research. A practical approach to this problem would be to reduce the complexity of the bipartite system while at the same time preserve its functionality. However, we find that existing coarse graining methods for monopartite networks usually fail for bipartite networks. In this paper, we use spectral analysis to design a coarse graining scheme specific for bipartite networks, which keeps their random walk properties unchanged. Numerical analysis on both artificial and real-world networks indicates that our coarse graining can better preserve most of the relevant spectral properties of the network. We validate our coarse graining method by directly comparing the mean first passage time of the walker in the original network and the reduced one.
12. Improving the treatment of coarse-grain electrostatics: CVCEL
SciTech Connect
Ceres, N.; Lavery, R.
2015-12-28
We propose an analytic approach for calculating the electrostatic energy of proteins or protein complexes in aqueous solution. This method, termed CVCEL (Circular Variance Continuum ELectrostatics), is fitted to Poisson calculations and is able to reproduce the corresponding energies for different choices of solute dielectric constant. CVCEL thus treats both solute charge interactions and charge self-energies, and it can also deal with salt solutions. Electrostatic damping notably depends on the degree of solvent exposure of the charges, quantified here in terms of circular variance, a measure that reflects the vectorial distribution of the neighbors around a given center. CVCEL energies can be calculated rapidly and have simple analytical derivatives. This approach avoids the need for calculating effective atomic volumes or Born radii. After describing how the method was developed, we present test results for coarse-grain proteins of different shapes and sizes, using different internal dielectric constants and different salt concentrations and also compare the results with those from simple distance-dependent models. We also show that the CVCEL approach can be used successfully to calculate the changes in electrostatic energy associated with changes in protein conformation or with protein-protein binding.
13. Interlaced coarse-graining for the dynamical cluster approximation
Haehner, Urs; Staar, Peter; Jiang, Mi; Maier, Thomas; Schulthess, Thomas
The negative sign problem remains a challenging limiting factor in quantum Monte Carlo simulations of strongly correlated fermionic many-body systems. The dynamical cluster approximation (DCA) makes this problem less severe by coarse-graining the momentum space to map the bulk lattice to a cluster embedded in a dynamical mean-field host. Here, we introduce a new form of an interlaced coarse-graining and compare it with the traditional coarse-graining. We show that it leads to more controlled results with weaker cluster shape and smoother cluster size dependence, which with increasing cluster size converge to the results obtained using the standard coarse-graining. In addition, the new coarse-graining reduces the severity of the fermionic sign problem. Therefore, it enables calculations on much larger clusters and can allow the evaluation of the exact infinite cluster size result via finite size scaling. To demonstrate this, we study the hole-doped two-dimensional Hubbard model and show that the interlaced coarse-graining in combination with the DCA+ algorithm permits the determination of the superconducting Tc on cluster sizes, for which the results can be fitted with the Kosterlitz-Thouless scaling law. This research used resources of the Oak Ridge Leadership Computing Facility (OLCF) awarded by the INCITE program, and of the Swiss National Supercomputing Center. OLCF is a DOE Office of Science User Facility supported under Contract DE-AC05-00OR22725.
14. Symmetry-adapted digital modeling III. Coarse-grained icosahedral viruses.
PubMed
Janner, A
2016-05-01
Considered is the coarse-grained modeling of icosahedral viruses in terms of a three-dimensional lattice (the digital modeling lattice) selected among the projected points in space of a six-dimensional icosahedral lattice. Backbone atomic positions (Cα's for the residues of the capsid and phosphorus atoms P for the genome nucleotides) are then indexed by their nearest lattice point. This leads to a fine-grained lattice point characterization of the full viral chains in the backbone approximation (denoted as digital modeling). Coarse-grained models then follow by a proper selection of the indexed backbone positions, where for each chain one can choose the desired coarseness. This approach is applied to three viruses, the Satellite tobacco mosaic virus, the bacteriophage MS2 and the Pariacoto virus, on the basis of structural data from the Brookhaven Protein Data Bank. In each case the various stages of the procedure are illustrated for a given coarse-grained model and the corresponding indexed positions are listed. Alternative coarse-grained models have been derived and compared. Comments on related results and approaches, found among the very large set of publications in this field, conclude this article. PMID:27126109
15. Energy-conserving coarse-graining of complex molecules.
PubMed
Español, Pep; Serrano, Mar; Pagonabarraga, Ignacio; Zúñiga, Ignacio
2016-05-25
Coarse-graining (CG) of complex molecules is a method to reach time scales that would be impossible to access through brute force molecular simulations. In this paper, we formulate a coarse-grained model for complex molecules using first principles caculations that ensures energy conservation. Each molecule is described in a coarse way by a thermal blob characterized by the position and momentum of the center of mass of the molecule, together with its internal energy as an additional degree of freedom. This level of description gives rise to an entropy-based framework instead of the usual one based on the configurational free energy (i.e. potential of mean force). The resulting dynamic equations, which account for an appropriate description of heat transfer at the coarse-grained level, have the structure of the dissipative particle dynamics with energy conservation (DPDE) model but with a clear microscopic underpinning. Under suitable approximations, we provide explicit microscopic expressions for each component (entropy, mean force, friction and conductivity coefficients) appearing in the coarse-grained model. These quantities can be computed directly using MD simulations. The proposed non-isothermal coarse-grained model is thermodynamically consistent and opens up a first principles CG strategy for the study of energy transport issues that are not accessible using current isothermal models. PMID:27127809
16. Volumes and surface areas: geometries and scaling relationships between coarse- grained and atomic structures.
PubMed
Flatow, Daniel; Leelananda, Sumudu P; Skliros, Aris; Kloczkowski, Andrzej; Jernigan, Robert L
2014-01-01
Computing volumes and surface areas of molecular structures is generally considered to be a solved problem, however, comparisons presented in this review show that different ways of computing surface areas and volumes can yield dramatically different values. Volumes and surface areas are the most basic geometric properties of structures, and estimating these becomes especially important for large scale simulations when individual components are being assembled in protein complexes or drugs being fitted into proteins. Good approximations of volumes and surfaces are derived from Delaunay tessellations, but these values can differ significantly from those from the rolling ball approach of Lee and Richards (3V webserver). The origin of these differences lies in the extended parts and the less well packed parts of the proteins, which are ignored in some approaches. Even though surface areas and volumes from the two approaches differ significantly, their correlations are high. Atomic models have been compared, and the poorly packed regions of proteins are found to be most different between the two approaches. The Delaunay complexes have been explored for both fully atomic and for coarse-grained representations of proteins based on only C(α) atoms. The scaling relationships between the fully atomic models and the coarse-grained model representations of proteins are reported, and the lines fit yield simple relationships for the surface areas and volumes as a function of the number of protein residues and the number of heavy atoms. Further, the atomic and coarse-grained values are strongly correlated and simple relationships are reported.
17. Coarse-grained dynamics of alignment in animal group models
Moon, Sung Joon; Levin, Simon; Kevrekidis, Yannis
2006-03-01
Coordinated motion in animal groups, such as bird flocks and fish schools, and their models gives rise to remarkable coherent structures. Using equation-free computational tools we explore the coarse-grained dynamics of a model for the orientational movement decision in animal groups, consisting of a small number of informed "leaders" and a large number of uninformed, nonidentical followers.'' The direction in which each group member is headed is characterized by a phase angle of a limit-cycle oscillator, whose dynamics are nonlinearly coupled with those of all the other group members. We identify a small number of proper coarse-grained variables (using uncertainty quantification methods) that describe the collective dynamics, and perform coarse projective integration and equation-free bifurcation analysis of the coarse-grained model behavior in these variables.
18. Mechanics of severing for large microtubule complexes revealed by coarse-grained simulations
Theisen, Kelly E.; Desai, Neha J.; Volski, Allison M.; Dima, Ruxandra I.
2013-09-01
We investigate the mechanical behavior of microtubule (MT) protofilaments under the action of bending forces, ramped up linearly in time, to provide insight into the severing of MTs by microtubule associated proteins (MAPs). We used the self-organized polymer model which employs a coarse-grained description of the protein chain and ran Brownian dynamics simulations accelerated on graphics processing units that allow us to follow the dynamics of a MT system on experimental timescales. Our study focused on the role played in the MT depolymerization dynamics by the inter-tubulin contacts a protofilament experiences when embedded in the MT lattice, and the number of binding sites of MAPs on MTs. We found that proteins inducing breaking of MTs must have at least three attachment points on any tubulin dimer from an isolated protofilament. In contrast, two points of contact would suffice when dimers are located in an intact MT lattice, in accord with experimental findings on MT severing proteins. Our results show that confinement of a protofilament in the MT lattice leads to a drastic reduction in the energy required for the removal of tubulin dimers, due to the drastic reduction in entropy. We further showed that there are differences in the energetic requirements based on the location of the dimer to be removed by severing. Comparing the energy of tubulin dimers removal revealed by our simulations with the amount of energy resulting from one ATP hydrolysis, which is the source of energy for all MAPs, we provided strong evidence for the experimental finding that severing proteins do not bind uniformly along the MT wall.
19. Coarse-Grained Prediction of RNA Loop Structures
PubMed Central
Liu, Liang; Chen, Shi-Jie
2012-01-01
One of the key issues in the theoretical prediction of RNA folding is the prediction of loop structure from the sequence. RNA loop free energies are dependent on the loop sequence content. However, most current models account only for the loop length-dependence. The previously developed “Vfold” model (a coarse-grained RNA folding model) provides an effective method to generate the complete ensemble of coarse-grained RNA loop and junction conformations. However, due to the lack of sequence-dependent scoring parameters, the method is unable to identify the native and near-native structures from the sequence. In this study, using a previously developed iterative method for extracting the knowledge-based potential parameters from the known structures, we derive a set of dinucleotide-based statistical potentials for RNA loops and junctions. A unique advantage of the approach is its ability to go beyond the the (known) native structures by accounting for the full free energy landscape, including all the nonnative folds. The benchmark tests indicate that for given loop/junction sequences, the statistical potentials enable successful predictions for the coarse-grained 3D structures from the complete conformational ensemble generated by the Vfold model. The predicted coarse-grained structures can provide useful initial folds for further detailed structural refinement. PMID:23144887
20. Coarse-Grained and Atomistic Modeling of Polyimides
NASA Technical Reports Server (NTRS)
Clancy, Thomas C.; Hinkley, Jeffrey A.
2004-01-01
A coarse-grained model for a set of three polyimide isomers is developed. Each polyimide is comprised of BPDA (3,3,4,4' - biphenyltetracarboxylic dianhydride) and one of three APB isomers: 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene or 1,3-bis(3-aminophenoxy)benzene. The coarse-grained model is constructed as a series of linked vectors following the contour of the polymer backbone. Beads located at the midpoint of each vector define centers for long range interaction energy between monomer subunits. A bulk simulation of each coarse-grained polyimide model is performed with a dynamic Monte Carlo procedure. These coarsegrained models are then reverse-mapped to fully atomistic models. The coarse-grained models show the expected trends in decreasing chain dimensions with increasing meta linkage in the APB section of the repeat unit, although these differences were minor due to the relatively short chains simulated here. Considerable differences are seen among the dynamic Monte Carlo properties of the three polyimide isomers. Decreasing relaxation times are seen with increasing meta linkage in the APB section of the repeat unit.
1. Development and application of coarse-grained models for lipids
Cui, Qiang
2013-03-01
I'll discuss a number of topics that represent our efforts in developing reliable molecular models for describing chemical and physical processes involving biomembranes. This is an exciting yet challenging research area because of the multiple length and time scales that are present in the relevant problems. Accordingly, we attempt to (1) understand the value and limitation of popular coarse-grained (CG) models for lipid membranes with either a particle or continuum representation; (2) develop new CG models that are appropriate for the particular problem of interest. As specific examples, I'll discuss (1) a comparison of atomistic, MARTINI (a particle based CG model) and continuum descriptions of a membrane fusion pore; (2) the development of a modified MARTINI model (BMW-MARTINI) that features a reliable description of membrane/water interfacial electrostatics and its application to cell-penetration peptides and membrane-bending proteins. Motivated specifically by the recent studies of Wong and co-workers, we compare the self-assembly behaviors of lipids with cationic peptides that include either Arg residues or a combination of Lys and hydrophobic residues; in particular, we attempt to reveal factors that stabilize the cubic double diamond'' Pn3m phase over the inverted hexagonal HII phase. For example, to explicitly test the importance of the bidentate hydrogen-bonding capability of Arg to the stabilization of negative Gaussian curvature, we also compare results using variants of the BMW-MARTINI model that treat the side chain of Arg with different levels of details. Collectively, the results suggest that both the bidentate feature of Arg and the overall electrostatic properties of cationic peptides are important to the self-assembly behavior of these peptides with lipids. The results are expected to have general implications to the mechanism of peptides and proteins that stimulate pore formation in biomembranes. Work in collaboration with Zhe Wu, Leili Zhang
2. Inferring a weighted elastic network from partial unfolding with coarse-grained simulations.
PubMed
de Mendonça, Matheus R; Rizzi, Leandro G; Contessoto, Vinicius; Leite, Vitor B P; Alves, Nelson A
2014-01-01
A number of studies have demonstrated that simple elastic network models can reproduce experimental B-factors, providing insights into the structure-function properties of proteins. Here, we report a study on how to improve an elastic network model and explore its performance by predicting the experimental B-factors. Elastic network models are built on the experimental Cα coordinates, and they only take the pairs of Cα atoms within a given cutoff distance rc into account. These models describe the interactions by elastic springs with the same force constant. We have developed a method based on numerical simulations with a simple coarse-grained force field, to attribute weights to these spring constants. This method considers the time that two Cα atoms remain connected in the network during partial unfolding, establishing a means of measuring the strength of each link. We examined two different coarse-grained force fields and explored the computation of these weights by unfolding the native structures.
3. Pairwise energies for polypeptide coarse-grained models derived from atomic force fields
Betancourt, Marcos R.; Omovie, Sheyore J.
2009-05-01
The energy parametrization of geometrically simplified versions of polypeptides, better known as polypeptide or protein coarse-grained models, is obtained from molecular dynamics and statistical methods. Residue pairwise interactions are derived by performing atomic-level simulations in explicit water for all 210 pairs of amino acids, where the amino acids are modified to closer match their structure and charges in polypeptides. Radial density functions are computed from equilibrium simulations for each pair of residues, from which statistical energies are extracted using the Boltzmann inversion method. The resulting models are compared to similar potentials obtained by knowledge based methods and to hydrophobic scales, resulting in significant similarities in spite of the model simplicity. However, it was found that glutamine, asparagine, lysine, and arginine are more attractive to other residues than anticipated, in part, due to their amphiphilic nature. In addition, equally charged residues appear more repulsive than expected. Difficulties in the calculation of knowledge based potentials and hydrophobicity scale for these cases, as well as sensitivity of the force field to polarization effects are suspected to cause this discrepancy. It is also shown that the coarse-grained model can identify native structures in decoy databases nearly as well as more elaborate knowledge based methods, in spite of its resolution limitations. In a test conducted with several proteins and corresponding decoys, the coarse-grained potential was able to identify the native state structure but not the original atomic force field.
4. Pairwise energies for polypeptide coarse-grained models derived from atomic force fields.
PubMed
Betancourt, Marcos R; Omovie, Sheyore J
2009-05-21
The energy parametrization of geometrically simplified versions of polypeptides, better known as polypeptide or protein coarse-grained models, is obtained from molecular dynamics and statistical methods. Residue pairwise interactions are derived by performing atomic-level simulations in explicit water for all 210 pairs of amino acids, where the amino acids are modified to closer match their structure and charges in polypeptides. Radial density functions are computed from equilibrium simulations for each pair of residues, from which statistical energies are extracted using the Boltzmann inversion method. The resulting models are compared to similar potentials obtained by knowledge based methods and to hydrophobic scales, resulting in significant similarities in spite of the model simplicity. However, it was found that glutamine, asparagine, lysine, and arginine are more attractive to other residues than anticipated, in part, due to their amphiphilic nature. In addition, equally charged residues appear more repulsive than expected. Difficulties in the calculation of knowledge based potentials and hydrophobicity scale for these cases, as well as sensitivity of the force field to polarization effects are suspected to cause this discrepancy. It is also shown that the coarse-grained model can identify native structures in decoy databases nearly as well as more elaborate knowledge based methods, in spite of its resolution limitations. In a test conducted with several proteins and corresponding decoys, the coarse-grained potential was able to identify the native state structure but not the original atomic force field.
5. Quantitative comparison of alternative methods for coarse-graining biological networks.
PubMed
Bowman, Gregory R; Meng, Luming; Huang, Xuhui
2013-09-28
Markov models and master equations are a powerful means of modeling dynamic processes like protein conformational changes. However, these models are often difficult to understand because of the enormous number of components and connections between them. Therefore, a variety of methods have been developed to facilitate understanding by coarse-graining these complex models. Here, we employ Bayesian model comparison to determine which of these coarse-graining methods provides the models that are most faithful to the original set of states. We find that the Bayesian agglomerative clustering engine and the hierarchical Nyström expansion graph (HNEG) typically provide the best performance. Surprisingly, the original Perron cluster cluster analysis (PCCA) method often provides the next best results, outperforming the newer PCCA+ method and the most probable paths algorithm. We also show that the differences between the models are qualitatively significant, rather than being minor shifts in the boundaries between states. The performance of the methods correlates well with the entropy of the resulting coarse-grainings, suggesting that finding states with more similar populations (i.e., avoiding low population states that may just be noise) gives better results. PMID:24089717
6. Quantitative comparison of alternative methods for coarse-graining biological networks
Bowman, Gregory R.; Meng, Luming; Huang, Xuhui
2013-09-01
Markov models and master equations are a powerful means of modeling dynamic processes like protein conformational changes. However, these models are often difficult to understand because of the enormous number of components and connections between them. Therefore, a variety of methods have been developed to facilitate understanding by coarse-graining these complex models. Here, we employ Bayesian model comparison to determine which of these coarse-graining methods provides the models that are most faithful to the original set of states. We find that the Bayesian agglomerative clustering engine and the hierarchical Nyström expansion graph (HNEG) typically provide the best performance. Surprisingly, the original Perron cluster cluster analysis (PCCA) method often provides the next best results, outperforming the newer PCCA+ method and the most probable paths algorithm. We also show that the differences between the models are qualitatively significant, rather than being minor shifts in the boundaries between states. The performance of the methods correlates well with the entropy of the resulting coarse-grainings, suggesting that finding states with more similar populations (i.e., avoiding low population states that may just be noise) gives better results.
7. Energetic frustrations in protein folding at residue resolution: a homologous simulation study of Im9 proteins.
PubMed
Sun, Yunxiang; Ming, Dengming
2014-01-01
Energetic frustration is becoming an important topic for understanding the mechanisms of protein folding, which is a long-standing big biological problem usually investigated by the free energy landscape theory. Despite the significant advances in probing the effects of folding frustrations on the overall features of protein folding pathways and folding intermediates, detailed characterizations of folding frustrations at an atomic or residue level are still lacking. In addition, how and to what extent folding frustrations interact with protein topology in determining folding mechanisms remains unclear. In this paper, we tried to understand energetic frustrations in the context of protein topology structures or native-contact networks by comparing the energetic frustrations of five homologous Im9 alpha-helix proteins that share very similar topology structures but have a single hydrophilic-to-hydrophobic mutual mutation. The folding simulations were performed using a coarse-grained Gō-like model, while non-native hydrophobic interactions were introduced as energetic frustrations using a Lennard-Jones potential function. Energetic frustrations were then examined at residue level based on φ-value analyses of the transition state ensemble structures and mapped back to native-contact networks. Our calculations show that energetic frustrations have highly heterogeneous influences on the folding of the four helices of the examined structures depending on the local environment of the frustration centers. Also, the closer the introduced frustration is to the center of the native-contact network, the larger the changes in the protein folding. Our findings add a new dimension to the understanding of protein folding the topology determination in that energetic frustrations works closely with native-contact networks to affect the protein folding.
8. A nucleotide-level coarse-grained model of RNA
SciTech Connect
Šulc, Petr; Ouldridge, Thomas E.; Louis, Ard A.; Romano, Flavio; Doye, Jonathan P. K.
2014-06-21
We present a new, nucleotide-level model for RNA, oxRNA, based on the coarse-graining methodology recently developed for the oxDNA model of DNA. The model is designed to reproduce structural, mechanical, and thermodynamic properties of RNA, and the coarse-graining level aims to retain the relevant physics for RNA hybridization and the structure of single- and double-stranded RNA. In order to explore its strengths and weaknesses, we test the model in a range of nanotechnological and biological settings. Applications explored include the folding thermodynamics of a pseudoknot, the formation of a kissing loop complex, the structure of a hexagonal RNA nanoring, and the unzipping of a hairpin motif. We argue that the model can be used for efficient simulations of the structure of systems with thousands of base pairs, and for the assembly of systems of up to hundreds of base pairs. The source code implementing the model is released for public use.
9. Coarse-Grained Molecular Dynamics: Dissipation Due to Internal Modes
SciTech Connect
Rudd, R E
2001-12-21
We describe progress on the issue of pathological elastic wave reflection in atomistic and multiscale simulation. First we briefly review Coarse-Grained Molecular Dynamics (CGMD). Originally CGMD was formulated as a Hamiltonian system in which energy is conserved. This formulation is useful for many applications, but recently CGMD has been extended to include generalized Langevin forces. Here we describe how Langevin dynamics arise naturally in CGMD, and we examine the implication for elastic wave scattering.
10. Systematic and Simulation-Free Coarse Graining of Polymeric Systems: A Structure-based Study
Yang, Delian; Wang, Qiang
2015-03-01
We propose a systematic and simulation-free strategy for coarse graining of multicomponent polymeric systems, where we use the Polymer Reference Interaction Site Model theory, instead of many-chain molecular simulations, to calculate the structure and thermodynamic properties of both the original and coarse-grained (CG) models, and quantitatively examine how the effective CG pair potentials and properties of CG systems vary with the coarse-graining level. Our strategy is general and versatile, is much faster than those using many-chain simulations, and practically solves the transferability problem of coarse graining. As an example, here we apply it to structure-based coarse graining of homopolymer melts, which matches the structure correlations of CG segments between the original and CG systems. Our numerical results clearly show that structure-based coarse graining cannot give thermodynamic consistency between the original and CG systems at any coarse-graining level due to the information loss of coarse graining.
11. REACH coarse-grained simulation of a cellulose fiber.
PubMed
Glass, Dennis C; Moritsugu, Kei; Cheng, Xiaolin; Smith, Jeremy C
2012-09-10
A molecular level understanding of the structure, dynamics and mechanics of cellulose fibers can aid in understanding the recalcitrance of biomass to hydrolysis in cellulosic biofuel production. Here, a residue-scale REACH (Realistic Extension Algorithm via Covariance Hessian) coarse-grained force field was derived from all-atom molecular dynamics (MD) simulations of the crystalline Iβ cellulose fibril. REACH maps the atomistic covariance matrix onto coarse-grained elastic force constants. The REACH force field was found to reproduce the positional fluctuations and low-frequency vibrational spectra from the all-atom model, allowing elastic properties of the cellulose fibril to be characterized using the coarse-grained force field with a speedup of >20 relative to atomistic MD on systems of the same size. The calculated longitudinal/transversal Young's modulus and the velocity of sound are in agreement with experiment. The persistence length of a 36-chain cellulose microcrystal was estimated to be ~380 μm. Finally, the normal-mode analysis with the REACH force field suggests that intrinsic dynamics might facilitate the deconstruction of the cellulose fibril from the hydrophobic surface.
12. Coarse graining of force fields for metal-organic frameworks.
PubMed
Dürholt, Johannes P; Galvelis, Raimondas; Schmid, Rochus
2016-03-14
We have adapted our genetic algorithm based optimization approach, originally developed to generate force field parameters from quantum mechanic reference data, to derive a first coarse grained force field for a MOF, taking the atomistic MOF-FF as a reference. On the example of the copper paddle-wheel based HKUST-1, a maximally coarse grained model, using a single bead for each three and four coordinated vertex, was developed as a proof of concept. By adding non-bonded interactions with a modified Buckingham potential, the resulting MOF-FF-CGNB is able to predict local deformation energies of the building blocks as well as bulk properties like the tbovs.pto energy difference or elastic constants in a semi-quantitative way. As expected, the negative thermal expansion of HKUST-1 is not reproduced by the maximally coarse grained model. At the expense of atomic resolution, substantially larger systems (up to tens of nanometers in size) can be simulated with respect to structural and mechanical properties, bridging the gap to the mesoscale. As an example the deformation of the [111] surface of HKUST-1 by a "tip" could be computed without artifacts from periodic images. PMID:26732756
13. Atomistic and Coarse-grained Simulations of Hexabenzocoronene Crystals
Ziogos, G.; Megariotis, G.; Theodorou, D. N.
2016-08-01
This study concerns atomistic and coarse-grained Molecular Dynamics simulations of pristine hexabenzocoronene (HBC) molecular crystals. HBC is a symmetric graphene flake of nanometric size that falls in the category of polyaromatic hydrocarbons, finding numerous applications in the field of organic electronics. The HBC molecule is simulated in its crystalline phase initially by means of an all-atom representation, where the molecules self- organize into well aligned molecular stacks, which in turn create a perfect monoclinic molecular crystal. The atomistic model reproduces fairly well the structural experimental properties and thus can be used as a reliable starting point for the development of a coarsegrained model following a bottom-up approach. The coarse-grained model is developed by applying Iterative Boltzmann Inversion, a systematic coarse-graining method which reproduces a set of target atomistic radial distribution functions and intramolecular distributions at the coarser level of description. This model allows the simulation of HBC crystals over longer time and length scales. The crystalline phase is analyzed in terms of the Saupe tensor and thermomechanical properties are probed at the atomistic level.
14. High capacitance of coarse-grained carbide derived carbon electrodes
DOE PAGESBeta
Dyatkin, Boris; Gogotsi, Oleksiy; Malinovskiy, Bohdan; Zozulya, Yuliya; Simon, Patrice; Gogotsi, Yury
2016-01-01
Here, we report exceptional electrochemical properties of supercapacitor electrodes composed of large, granular carbide-derived carbon (CDC) particles. We synthesized 70–250 μm sized particles with high surface area and a narrow pore size distribution, using a titanium carbide (TiC) precursor. Electrochemical cycling of these coarse-grained powders defied conventional wisdom that a small particle size is strictly required for supercapacitor electrodes and allowed high charge storage densities, rapid transport, and good rate handling ability. Moreover, the material showcased capacitance above 100 F g-1 at sweep rates as high as 250 mV s-1 in organic electrolyte. 250–1000 micron thick dense CDC films withmore » up to 80 mg cm-2 loading showed superior areal capacitances. The material significantly outperformed its activated carbon counterpart in organic electrolytes and ionic liquids. Furthermore, large internal/external surface ratio of coarse-grained carbons allowed the resulting electrodes to maintain high electrochemical stability up to 3.1 V in ionic liquid electrolyte. In addition to presenting novel insights into the electrosorption process, these coarse-grained carbons offer a pathway to low-cost, high-performance implementation of supercapacitors in automotive and grid-storage applications.« less
15. High capacitance of coarse-grained carbide derived carbon electrodes
SciTech Connect
Dyatkin, Boris; Gogotsi, Oleksiy; Malinovskiy, Bohdan; Zozulya, Yuliya; Simon, Patrice; Gogotsi, Yury
2016-01-01
Here, we report exceptional electrochemical properties of supercapacitor electrodes composed of large, granular carbide-derived carbon (CDC) particles. We synthesized 70–250 μm sized particles with high surface area and a narrow pore size distribution, using a titanium carbide (TiC) precursor. Electrochemical cycling of these coarse-grained powders defied conventional wisdom that a small particle size is strictly required for supercapacitor electrodes and allowed high charge storage densities, rapid transport, and good rate handling ability. Moreover, the material showcased capacitance above 100 F g-1 at sweep rates as high as 250 mV s-1 in organic electrolyte. 250–1000 micron thick dense CDC films with up to 80 mg cm-2 loading showed superior areal capacitances. The material significantly outperformed its activated carbon counterpart in organic electrolytes and ionic liquids. Furthermore, large internal/external surface ratio of coarse-grained carbons allowed the resulting electrodes to maintain high electrochemical stability up to 3.1 V in ionic liquid electrolyte. In addition to presenting novel insights into the electrosorption process, these coarse-grained carbons offer a pathway to low-cost, high-performance implementation of supercapacitors in automotive and grid-storage applications.
16. High capacitance of coarse-grained carbide derived carbon electrodes
Dyatkin, Boris; Gogotsi, Oleksiy; Malinovskiy, Bohdan; Zozulya, Yuliya; Simon, Patrice; Gogotsi, Yury
2016-02-01
We report exceptional electrochemical properties of supercapacitor electrodes composed of large, granular carbide-derived carbon (CDC) particles. Using a titanium carbide (TiC) precursor, we synthesized 70-250 μm sized particles with high surface area and a narrow pore size distribution. Electrochemical cycling of these coarse-grained powders defied conventional wisdom that a small particle size is strictly required for supercapacitor electrodes and allowed high charge storage densities, rapid transport, and good rate handling ability. The material showcased capacitance above 100 F g-1 at sweep rates as high as 250 mV s-1 in organic electrolyte. 250-1000 micron thick dense CDC films with up to 80 mg cm-2 loading showed superior areal capacitances. The material significantly outperformed its activated carbon counterpart in organic electrolytes and ionic liquids. Furthermore, large internal/external surface ratio of coarse-grained carbons allowed the resulting electrodes to maintain high electrochemical stability up to 3.1 V in ionic liquid electrolyte. In addition to presenting novel insights into the electrosorption process, these coarse-grained carbons offer a pathway to low-cost, high-performance implementation of supercapacitors in automotive and grid-storage applications.
17. Coarse-grained models for aqueous polyethylene glycol solutions.
PubMed
Choi, Eunsong; Mondal, Jagannath; Yethiraj, Arun
2014-01-01
A new coarse-grained force field is developed for polyethylene glycol (PEG) in water. The force field is based on the MARTINI model but with the big multipole water (BMW) model for the solvent. The polymer force field is reparameterized using the MARTINI protocol. The new force field removes the ring-like conformations seen in simulations of short chains with the MARTINI force field; these conformations are not observed in atomistic simulations. We also investigate the effect of using parameters for the end-group that are different from those for the repeat units, with the MARTINI and BMW/MARTINI models. We find that the new BMW/MARTINI force field removes the ring-like conformations seen in the MARTINI models and has more accurate predictions for the density of neat PEG. However, solvent-separated-pairs between chain ends and slow dynamics of the PEG reflect its own artifacts. We also carry out fine-grained simulations of PEG with bundled water clusters and show that the water bundling can lead to ring-like conformations of the polymer molecules. The simulations emphasize the pitfalls of coarse-graining several molecules into one site and suggest that polymer-solvent systems might be a stringent test for coarse-grained force fields. PMID:24350686
18. Bayesian calibration of coarse-grained forces: Efficiently addressing transferability
Patrone, Paul N.; Rosch, Thomas W.; Phelan, Frederick R.
2016-04-01
Generating and calibrating forces that are transferable across a range of state-points remains a challenging task in coarse-grained (CG) molecular dynamics. In this work, we present a coarse-graining workflow, inspired by ideas from uncertainty quantification and numerical analysis, to address this problem. The key idea behind our approach is to introduce a Bayesian correction algorithm that uses functional derivatives of CG simulations to rapidly and inexpensively recalibrate initial estimates f0 of forces anchored by standard methods such as force-matching. Taking density-temperature relationships as a running example, we demonstrate that this algorithm, in concert with various interpolation schemes, can be used to efficiently compute physically reasonable force curves on a fine grid of state-points. Importantly, we show that our workflow is robust to several choices available to the modeler, including the interpolation schemes and tools used to construct f0. In a related vein, we also demonstrate that our approach can speed up coarse-graining by reducing the number of atomistic simulations needed as inputs to standard methods for generating CG forces.
19. Coarse-graining two-dimensional turbulence via dynamical optimization
Turkington, Bruce; Chen, Qian-Yong; Thalabard, Simon
2016-10-01
A model reduction technique based on an optimization principle is employed to coarse-grain inviscid, incompressible fluid dynamics in two dimensions. In this reduction the spectrally-truncated vorticity equation defines the microdynamics, while the macroscopic state space consists of quasi-equilibrium trial probability densities on the microscopic phase space, which are parameterized by the means and variances of the low modes of the vorticity. A macroscopic path therefore represents a coarse-grained approximation to the evolution of a nonequilibrium ensemble of microscopic solutions. Closure in terms of the vector of resolved variables, namely, the means and variances of the low modes, is achieved by minimizing over all feasible paths the time integral of their mean-squared residual with respect to the Liouville equation. The equations governing the optimal path are deduced from Hamilton-Jacobi theory. The coarse-grained dynamics derived by this optimization technique contains a scale-dependent eddy viscosity, modified nonlinear interactions between the low mode means, and a nonlinear coupling between the mean and variance of each low mode. The predictive skill of this optimal closure is validated quantitatively by comparing it against direct numerical simulations. These tests show that good agreement is achieved without adjusting any closure parameters.
20. Coarse-graining stochastic biochemical networks: adiabaticity and fast simulations
SciTech Connect
Nemenman, Ilya; Sinitsyn, Nikolai; Hengartner, Nick
2008-01-01
We propose a universal approach for analysis and fast simulations of stiff stochastic biochemical kinetics networks, which rests on elimination of fast chemical species without a loss of information about mesoscoplc, non-Poissonian fluctuations of the slow ones. Our approach, which is similar to the Born-Oppenhelmer approximation in quantum mechanics, follows from the stochastic path Integral representation of the cumulant generating function of reaction events. In applications with a small number of chemIcal reactions, It produces analytical expressions for cumulants of chemical fluxes between the slow variables. This allows for a low-dimensional, Interpretable representation and can be used for coarse-grained numerical simulation schemes with a small computational complexity and yet high accuracy. As an example, we derive the coarse-grained description for a chain of biochemical reactions, and show that the coarse-grained and the microscopic simulations are in an agreement, but the coarse-gralned simulations are three orders of magnitude faster.
1. Optimization of Analytical Potentials for Coarse-Grained Biopolymer Models.
PubMed
Mereghetti, Paolo; Maccari, Giuseppe; Spampinato, Giulia Lia Beatrice; Tozzini, Valentina
2016-08-25
The increasing trend in the recent literature on coarse grained (CG) models testifies their impact in the study of complex systems. However, the CG model landscape is variegated: even considering a given resolution level, the force fields are very heterogeneous and optimized with very different parametrization procedures. Along the road for standardization of CG models for biopolymers, here we describe a strategy to aid building and optimization of statistics based analytical force fields and its implementation in the software package AsParaGS (Assisted Parameterization platform for coarse Grained modelS). Our method is based on the use and optimization of analytical potentials, optimized by targeting internal variables statistical distributions by means of the combination of different algorithms (i.e., relative entropy driven stochastic exploration of the parameter space and iterative Boltzmann inversion). This allows designing a custom model that endows the force field terms with a physically sound meaning. Furthermore, the level of transferability and accuracy can be tuned through the choice of statistical data set composition. The method-illustrated by means of applications to helical polypeptides-also involves the analysis of two and three variable distributions, and allows handling issues related to the FF term correlations. AsParaGS is interfaced with general-purpose molecular dynamics codes and currently implements the "minimalist" subclass of CG models (i.e., one bead per amino acid, Cα based). Extensions to nucleic acids and different levels of coarse graining are in the course. PMID:27150459
2. Bayesian calibration of coarse-grained forces: Efficiently addressing transferability.
PubMed
Patrone, Paul N; Rosch, Thomas W; Phelan, Frederick R
2016-04-21
Generating and calibrating forces that are transferable across a range of state-points remains a challenging task in coarse-grained (CG) molecular dynamics. In this work, we present a coarse-graining workflow, inspired by ideas from uncertainty quantification and numerical analysis, to address this problem. The key idea behind our approach is to introduce a Bayesian correction algorithm that uses functional derivatives of CG simulations to rapidly and inexpensively recalibrate initial estimates f0 of forces anchored by standard methods such as force-matching. Taking density-temperature relationships as a running example, we demonstrate that this algorithm, in concert with various interpolation schemes, can be used to efficiently compute physically reasonable force curves on a fine grid of state-points. Importantly, we show that our workflow is robust to several choices available to the modeler, including the interpolation schemes and tools used to construct f0. In a related vein, we also demonstrate that our approach can speed up coarse-graining by reducing the number of atomistic simulations needed as inputs to standard methods for generating CG forces.
3. The multiscale coarse-graining method. XI. Accurate interactions based on the centers of charge of coarse-grained sites.
PubMed
Cao, Zhen; Voth, Gregory A
2015-12-28
It is essential to be able to systematically construct coarse-grained (CG) models that can efficiently and accurately reproduce key properties of higher-resolution models such as all-atom. To fulfill this goal, a mapping operator is needed to transform the higher-resolution configuration to a CG configuration. Certain mapping operators, however, may lose information related to the underlying electrostatic properties. In this paper, a new mapping operator based on the centers of charge of CG sites is proposed to address this issue. Four example systems are chosen to demonstrate this concept. Within the multiscale coarse-graining framework, CG models that use this mapping operator are found to better reproduce the structural correlations of atomistic models. The present work also demonstrates the flexibility of the mapping operator and the robustness of the force matching method. For instance, important functional groups can be isolated and emphasized in the CG model. PMID:26723601
4. The multiscale coarse-graining method. XI. Accurate interactions based on the centers of charge of coarse-grained sites
SciTech Connect
Cao, Zhen; Voth, Gregory A.
2015-12-28
It is essential to be able to systematically construct coarse-grained (CG) models that can efficiently and accurately reproduce key properties of higher-resolution models such as all-atom. To fulfill this goal, a mapping operator is needed to transform the higher-resolution configuration to a CG configuration. Certain mapping operators, however, may lose information related to the underlying electrostatic properties. In this paper, a new mapping operator based on the centers of charge of CG sites is proposed to address this issue. Four example systems are chosen to demonstrate this concept. Within the multiscale coarse-graining framework, CG models that use this mapping operator are found to better reproduce the structural correlations of atomistic models. The present work also demonstrates the flexibility of the mapping operator and the robustness of the force matching method. For instance, important functional groups can be isolated and emphasized in the CG model.
5. Application of information theory to a three-body coarse-grained representation of proteins in the PDB: insights into the structural and evolutionary roles of residues in protein structure.
PubMed
Thompson, Jared J; Tabatabaei Ghomi, Hamed; Lill, Markus A
2014-12-01
Knowledge-based methods for analyzing protein structures, such as statistical potentials, primarily consider the distances between pairs of bodies (atoms or groups of atoms). Considerations of several bodies simultaneously are generally used to characterize bonded structural elements or those in close contact with each other, but historically do not consider atoms that are not in direct contact with each other. In this report, we introduce an information-theoretic method for detecting and quantifying distance-dependent through-space multibody relationships between the sidechains of three residues. The technique introduced is capable of producing convergent and consistent results when applied to a sufficiently large database of randomly chosen, experimentally solved protein structures. The results of our study can be shown to reproduce established physico-chemical properties of residues as well as more recently discovered properties and interactions. These results offer insight into the numerous roles that residues play in protein structure, as well as relationships between residue function, protein structure, and evolution. The techniques and insights presented in this work should be useful in the future development of novel knowledge-based tools for the evaluation of protein structure.
6. Dynamical coarse grained models with realistic time dependence
Andersen, Hans
2015-03-01
Coarse grained (CG) models of molecular systems, with fewer mechanical degrees of freedom than an all-atom model, are used extensively in chemical physics. It is generally accepted that a coarse grained model that accurately describes equilibrium structural properties (as a result of having a well constructed CG potential energy function) does not necessarily exhibit appropriate dynamical behavior when simulated using conservative Hamiltonian dynamics for the CG degrees of freedom on the CG potential energy surface. Attempts to develop accurate CG dynamic models usually focus on replacing Hamiltonian motion by stochastic but Markovian dynamics on that surface, such as Langevin or Brownian dynamics. However, depending on the nature of the system and the extent of the coarse graining, a Markovian dynamics for the CG degrees of freedom may not be appropriate. We consider the problem of constructing dynamic CG models within the context of the Multi-Scale Coarse Graining (MS-CG) method of Voth and coworkers. We propose a method of converting an MS-CG model into a dynamic CG model by adding degrees of freedom to it in the form of a small number of fictitious particles that interact with the CG degrees of freedom in simple ways and that are subject to Langevin forces. The dynamic models are members of a class of nonlinear systems interacting with special heat baths that was studied by Zwanzig [R. Zwanzig, J. Stat. Phys. 9, 215 (1973)]. The dynamic models generate a non-Markovian dynamics for the CG degrees of freedom, but they can be easily simulated using standard molecular dynamics simulation programs. We present tests of this method on a series of simple examples that demonstrate that the method provides realistic dynamical CG models that have non-Markovian or close to Markovian behavior that is consistent with the actual dynamical behavior of the all-atom system used to construct the CG model. The dynamic CG models have computational requirements that are similar to
7. The multiscale coarse-graining method. X. Improved algorithms for constructing coarse-grained potentials for molecular systems
Das, Avisek; Lu, Lanyuan; Andersen, Hans C.; Voth, Gregory A.
2012-05-01
The multiscale coarse-graining (MS-CG) method uses simulation data for an atomistic model of a system to construct a coarse-grained (CG) potential for a coarse-grained model of the system. The CG potential is a variational approximation for the true potential of mean force of the degrees of freedom retained in the CG model. The variational calculation uses information about the atomistic positions and forces in the simulation data. In principle, the resulting MS-CG potential will be an accurate representation of the true CG potential if the basis set for the variational calculation is complete enough and the canonical distribution of atomistic states is well sampled by the data set. In practice, atomistic configurations that have very high potential energy are not sampled. As a result there usually is a region of CG configuration space that is not sampled and about which the data set contains no information regarding the gradient of the true potential. The MS-CG potential obtained from a variational calculation will not necessarily be accurate in this unsampled region. A priori considerations make it clear that the true CG potential of mean force must be very large and positive in that region. To obtain an MS-CG potential whose behavior in the sampled region is determined by the atomistic data set, and whose behavior in the unsampled region is large and positive, it is necessary to intervene in the variational calculation in some way. In this paper, we discuss and compare two such methods of intervention, which have been used in previous MS-CG calculations for dealing with nonbonded interactions. For the test systems studied, the two methods give similar results and yield MS-CG potentials that are limited in accuracy only by the incompleteness of the basis set and the statistical error of associated with the set of atomistic configurations used. The use of such methods is important for obtaining accurate CG potentials.
8. Hybrid simulations: combining atomistic and coarse-grained force fields using virtual sites.
PubMed
Rzepiela, Andrzej J; Louhivuori, Martti; Peter, Christine; Marrink, Siewert J
2011-06-14
Hybrid simulations, in which part of the system is represented at atomic resolution and the remaining part at a reduced, coarse-grained, level offer a powerful way to combine the accuracy associated with the atomistic force fields to the sampling speed obtained with coarse-grained (CG) potentials. In this work we introduce a straightforward scheme to perform hybrid simulations, making use of virtual sites to couple the two levels of resolution. With the help of these virtual sites interactions between molecules at different levels of resolution, i.e. between CG and atomistic molecules, are treated the same way as the pure CG-CG interactions. To test our method, we combine the Gromos atomistic force field with a number of coarse-grained potentials, obtained through several approaches that are designed to obtain CG potentials based on an existing atomistic model, namely iterative Boltzmann inversion, force matching, and a potential of mean force subtraction procedure (SB). We also explore the use of the MARTINI force field for the CG potential. A simple system, consisting of atomistic butane molecules dissolved in CG butane, is used to study the performance of our hybrid scheme. Based on the potentials of mean force for atomistic butane in CG solvent, and the properties of 1:1 mixtures of atomistic and CG butane which should exhibit ideal mixing behavior, we conclude that the MARTINI and SB potentials are particularly suited to be combined with the atomistic force field. The MARTINI potential is subsequently used to perform hybrid simulations of atomistic dialanine peptides in both CG butane and water. Compared to a fully atomistic description of the system, the hybrid description gives similar results provided that the dielectric screening of water is accounted for. Within the field of biomolecules, our method appears ideally suited to study e.g. protein-ligand binding, where the active site and ligand are modeled in atomistic detail and the rest of the protein
9. Coarse-grained modeling of RNA 3D structure.
PubMed
Dawson, Wayne K; Maciejczyk, Maciej; Jankowska, Elzbieta J; Bujnicki, Janusz M
2016-07-01
Functional RNA molecules depend on three-dimensional (3D) structures to carry out their tasks within the cell. Understanding how these molecules interact to carry out their biological roles requires a detailed knowledge of RNA 3D structure and dynamics as well as thermodynamics, which strongly governs the folding of RNA and RNA-RNA interactions as well as a host of other interactions within the cellular environment. Experimental determination of these properties is difficult, and various computational methods have been developed to model the folding of RNA 3D structures and their interactions with other molecules. However, computational methods also have their limitations, especially when the biological effects demand computation of the dynamics beyond a few hundred nanoseconds. For the researcher confronted with such challenges, a more amenable approach is to resort to coarse-grained modeling to reduce the number of data points and computational demand to a more tractable size, while sacrificing as little critical information as possible. This review presents an introduction to the topic of coarse-grained modeling of RNA 3D structures and dynamics, covering both high- and low-resolution strategies. We discuss how physics-based approaches compare with knowledge based methods that rely on databases of information. In the course of this review, we discuss important aspects in the reasoning process behind building different models and the goals and pitfalls that can result.
10. Effective mobility of dislocations from systematic coarse-graining
Kooiman, M.; Hütter, M.; Geers, MGD
2015-06-01
The dynamics of large amounts of dislocations governs the plastic response of crystalline materials. In this contribution we discuss the relation between the mobility of discrete dislocations and the resulting flow rule for coarse-grained dislocation densities. The mobilities used in literature on these levels are quite different, for example in terms of their intrinsic the stress dependence. To establish the relation across the scales, we have derived the macroscopic evolution equations of dislocation densities from the equations of motion of individual dislocations by means of systematic coarse-graining. From this, we can identify a memory kernel relating the driving force and the flux of dislocations. This kernel can be considered as an effective macroscopic mobility with two contributions; a direct contribution related to the overdamped motion of individual dislocations, and an emergent contribution that arises from time correlations of fluctuations in the Peach-Koehler force. Scaling analysis shows that the latter contribution is dominant for dislocations in metals at room temperature. We also discuss several concerns related to the separation of timescales.
11. Coarse-graining the structure of polycyclic aromatic hydrocarbons clusters.
PubMed
Hernández-Rojas, J; Calvo, F; Wales, D J
2016-05-18
Clusters of polycyclic aromatic hydrocarbons (PAHs) are essential components of soot and may concentrate a significant fraction of carbon matter in the interstellar medium. In this contribution, coarse-grained potentials are parameterized using all-atom reference data to model PAH molecules, such as coronene (C24H12) or circumcoronene (C54H18), and their aggregates. Low-energy structures of pure coronene or circumcoronene clusters obtained using basin-hopping global optimization are found to agree with atomistic results, and consist of finite 1D columnar motifs, sometimes juxtaposed in larger clusters. The structures are only weakly perturbed when quadrupolar interactions are included. π-Stacking also dominates in binary coronene/circumcoronene aggregates, although intriguing motifs are predicted in which one or more molecules are sandwiched between the other PAH species. The coarse-grained model is also extended to account for interaction with a flat graphitic substrate. In this case, binding is stronger with the substrate than with other molecules, and the PAHs are predicted to arrange into a flat triangular monolayer. PMID:27055581
12. Tensile fracture of coarse-Grained cast austenitic manganese steels
Rittel, D.; Roman, I.
1988-09-01
Tensile fracture of coarse-grained (0.25 to 1 mm) cast austenitic manganese (Hadfield) steels has been investigated. Numerous surface discontinuities nucleate in coarse slip bands, on the heavily deformed surface of tensile specimens. These discontinuities do not propagate radially and final fracture results from central specimen cracking at higher strains. On the microscopic scale, bulk voids nucleate during the entire plastic deformation and they do not coalesce by shear localization (e.g., void-sheet) mechanism. Close voids coalesce by internal necking, whereas distant voids are bridged by means of small voids which nucleate at later stages of the plastic deformation. The high toughness of Hadfield steels is due to their high strain-hardening capacity which stabilizes the plastic deformation, and avoids shear localization and loss of load-bearing capacity. The observed dependence of measured mechanical properties on the specimen’s geometry results from the development of a surface layer which charac-terizes the deformation of this coarse-grained material.
Gupta, Satish
2013-06-01
To develop better understanding of the shock wave induced deformation behavior of coarse grain alumina ceramics, and for measurement of its Hugoniot Elastic Limit (HEL), in-situ and recovery gas gun experiments have been carried out on coarse grain alumina (grain size ~ 10 μm), prepared in the form of discs (>99.9% TMD) by pressure-less sintering of alpha alumina powder at 1583 K. The HEL value of 1.9 GPa has been determined from the kink in the pressure history recorded using piezoresistance gauge and also from the free surface velocity history of the sample shocked to 9 GPa. The nano-indentation measurements on the alumina samples shocked to 6.5 GPa showed hardness value 15% lower than 21.3 GPa for unshocked alumina, and strong Indentation Size Effect (ISE); the hardness value was still lower and the ISE was stronger for the sample shocked to 12 GPa. The XRD measurements showed reduced particle size and increased microstrains in the shocked alumina fragments. SEM, FESEM and TEM measurements on shock treated samples showed presence of grain localized micro- and nano-scale deformations, micro-cleavages, grain-boundary microcracks, extensive shear induced deformations, and localized micro-fractures, etc. These observations led to the development of a qualitative model for the damage initiation and its subsequent growth mechanisms in shocked alumina. The work performed in collaboration with K.D. Joshi of BARC and A.K. Mukhopadhyay of CGCRI.
14. An exactly solvable coarse-grained model for species diversity
Suweis, Samir; Rinaldo, Andrea; Maritan, Amos
2012-07-01
We present novel analytical results concerning ecosystem species diversity that stem from a proposed coarse-grained neutral model based on birth-death processes. The relevance of the problem lies in the urgency for understanding and synthesizing both theoretical results from ecological neutral theory and empirical evidence on species diversity preservation. The neutral model of biodiversity deals with ecosystems at the same trophic level, where per capita vital rates are assumed to be species independent. Closed-form analytical solutions for the neutral theory are obtained within a coarse-grained model, where the only input is the species persistence time distribution. Our results pertain to: the probability distribution function of the number of species in the ecosystem, both in transient and in stationary states; the n-point connected time correlation function; and the survival probability, defined as the distribution of time spans to local extinction for a species randomly sampled from the community. Analytical predictions are also tested on empirical data from an estuarine fish ecosystem. We find that emerging properties of the ecosystem are very robust and do not depend on specific details of the model, with implications for biodiversity and conservation biology.
15. DNA Duplex Formation with a Coarse-Grained Model
PubMed Central
2015-01-01
A middle-resolution coarse-grained model of DNA is proposed. The DNA chain is built of spherical and planar rigid bodies connected by elastic virtual bonds. The bonded part of the potential energy function is fit to potentials of mean force of model systems. The rigid bodies are sets of neutral, charged, and dipolar beads. Electrostatic and van der Waals interactions are parametrized by our recently developed procedure [Maciejczyk, M.; Spasic, A.; Liwo, A.; Scheraga, H.A. J. Comp. Chem.2010, 31, 1644]. Interactions with the solvent and an ionic cloud are approximated by a multipole–multipole Debye–Hückel model. A very efficient R-RATTLE algorithm, for integrating the movement of rigid bodies, is implemented. It is the first coarse-grained model, in which both bonded and nonbonded interactions were parametrized ab initio and which folds stable double helices from separated complementary strands, with the final conformation close to the geometry of experimentally determined structures. PMID:25400520
16. Coarse-grained rigid blob model for soft matter simulations
Chao, Sheng D.; Kress, Joel D.; Redondo, Antonio
2005-06-01
We have developed a coarse-grained multiscale molecular simulation method for soft matter systems that directly incorporates stereochemical information. We divide the material into disjoint groups of atoms or particles that move as separate rigid bodies; we call these groups "rigid blobs," hence the name coarse-grained rigid blob model. The method is enabled by the construction of transferable interblob potentials that approximate the net intermolecular interactions, as obtained from ab initio electronic structure calculations, other all-atom empirical potentials, experimental data, or any combination of the above. We utilize a multipolar expansion to obtain the interblob potential-energy functions. The series, which contains controllable approximations that allow us to estimate the errors, approaches the original intermolecular potential as the number of terms increases. Using a novel numerical algorithm, we can calculate the interblob potentials very efficiently in terms of a few interaction moment tensors. This reduces the labor well beyond what is required in standard molecular-dynamics calculations and allows large-scale simulations for temporal scales commensurate with characteristic times of nano- and mesoscale systems. A detailed derivation of the formulas is presented, followed by illustrative applications to several systems showing that the method can effectively capture realistic microscopic details and can easily extend to large-scale simulations.
17. Multiscale design of coarse-grained elastic network-based potentials for the μ opioid receptor.
PubMed
Fossépré, Mathieu; Leherte, Laurence; Laaksonen, Aatto; Vercauteren, Daniel P
2016-09-01
Despite progress in computer modeling, most biological processes are still out of reach when using all-atom (AA) models. Coarse-grained (CG) models allow classical molecular dynamics (MD) simulations to be accelerated. Although simplification of spatial resolution at different levels is often investigated, simplification of the CG potential in itself has been less common. CG potentials are often similar to AA potentials. In this work, we consider the design and reliability of purely mechanical CG models of the μ opioid receptor (μOR), a G protein-coupled receptor (GPCR). In this sense, CG force fields (FF) consist of a set of holonomic constraints guided by an elastic network model (ENM). Even though ENMs are used widely to perform normal mode analysis (NMA), they are not often implemented as a single FF in the context of MD simulations. In this work, various ENM-like potentials were investigated by varying their force constant schemes and connectivity patterns. A method was established to systematically parameterize ENM-like potentials at different spatial resolutions by using AA data. To do so, new descriptors were introduced. The choice of conformation descriptors that also include flexibility information is important for a reliable parameterization of ENMs with different degrees of sensitivity. Hence, ENM-like potentials, with specific parameters, can be sufficient to accurately reproduce AA MD simulations of μOR at highly coarse-grained resolutions. Therefore, the essence of the flexibility properties of μOR can be captured with simple models at different CG spatial resolutions, opening the way to mechanical approaches to understanding GPCR functions. Graphical Abstract All atom structure, residue interaction network and coarse-grained elastic network models of the μ opioid receptor (μOR). PMID:27566318
18. Multiscale design of coarse-grained elastic network-based potentials for the μ opioid receptor.
PubMed
Fossépré, Mathieu; Leherte, Laurence; Laaksonen, Aatto; Vercauteren, Daniel P
2016-09-01
Despite progress in computer modeling, most biological processes are still out of reach when using all-atom (AA) models. Coarse-grained (CG) models allow classical molecular dynamics (MD) simulations to be accelerated. Although simplification of spatial resolution at different levels is often investigated, simplification of the CG potential in itself has been less common. CG potentials are often similar to AA potentials. In this work, we consider the design and reliability of purely mechanical CG models of the μ opioid receptor (μOR), a G protein-coupled receptor (GPCR). In this sense, CG force fields (FF) consist of a set of holonomic constraints guided by an elastic network model (ENM). Even though ENMs are used widely to perform normal mode analysis (NMA), they are not often implemented as a single FF in the context of MD simulations. In this work, various ENM-like potentials were investigated by varying their force constant schemes and connectivity patterns. A method was established to systematically parameterize ENM-like potentials at different spatial resolutions by using AA data. To do so, new descriptors were introduced. The choice of conformation descriptors that also include flexibility information is important for a reliable parameterization of ENMs with different degrees of sensitivity. Hence, ENM-like potentials, with specific parameters, can be sufficient to accurately reproduce AA MD simulations of μOR at highly coarse-grained resolutions. Therefore, the essence of the flexibility properties of μOR can be captured with simple models at different CG spatial resolutions, opening the way to mechanical approaches to understanding GPCR functions. Graphical Abstract All atom structure, residue interaction network and coarse-grained elastic network models of the μ opioid receptor (μOR).
19. Coarse Graining to Investigate Membrane Induced Peptide Folding of Anticancer Peptides
Ganesan, Sai; Xu, Hongcheng; Matysiak, Silvina
Information about membrane induced peptide folding mechanisms using all-atom molecular dynamics simulations is a challenge due to time and length scale issues.We recently developed a low resolution Water Explicit Polarizable PROtein coarse-grained Model by adding oppositely charged dummy particles inside protein backbone beads.These two dummy particles represent a fluctuating dipole,thus introducing structural polarization into the coarse-grained model.With this model,we were able to achieve significant α- β secondary structure content de novo,without any added bias.We extended the model to zwitterionic and anionic lipids,by adding oppositely charged dummy particles inside polar beads, to capture the ability of the head group region to form hydrogen bonds.We use zwitterionic POPC and anionic POPS as our model lipids, and a cationic anticancer peptide,SVS1,as our model peptide.We have characterized the driving forces for SVS1 folding on lipid bilayers with varying anionic and zwitterionic lipid compositions.Based on our results, dipolar interactions between peptide backbone and lipid head groups contribute to stabilize folded conformations.Cooperativity in folding is induced by both intra peptide and membrane-peptide interaction.
20. Systematic hierarchical coarse-graining with the inverse Monte Carlo method
SciTech Connect
Lyubartsev, Alexander P.; Naômé, Aymeric; Vercauteren, Daniel P.; Laaksonen, Aatto
2015-12-28
We outline our coarse-graining strategy for linking micro- and mesoscales of soft matter and biological systems. The method is based on effective pairwise interaction potentials obtained in detailed ab initio or classical atomistic Molecular Dynamics (MD) simulations, which can be used in simulations at less accurate level after scaling up the size. The effective potentials are obtained by applying the inverse Monte Carlo (IMC) method [A. P. Lyubartsev and A. Laaksonen, Phys. Rev. E 52(4), 3730–3737 (1995)] on a chosen subset of degrees of freedom described in terms of radial distribution functions. An in-house software package MagiC is developed to obtain the effective potentials for arbitrary molecular systems. In this work we compute effective potentials to model DNA-protein interactions (bacterial LiaR regulator bound to a 26 base pairs DNA fragment) at physiological salt concentration at a coarse-grained (CG) level. Normally the IMC CG pair-potentials are used directly as look-up tables but here we have fitted them to five Gaussians and a repulsive wall. Results show stable association between DNA and the model protein as well as similar position fluctuation profile.
1. Systematic hierarchical coarse-graining with the inverse Monte Carlo method
Lyubartsev, Alexander P.; Naômé, Aymeric; Vercauteren, Daniel P.; Laaksonen, Aatto
2015-12-01
We outline our coarse-graining strategy for linking micro- and mesoscales of soft matter and biological systems. The method is based on effective pairwise interaction potentials obtained in detailed ab initio or classical atomistic Molecular Dynamics (MD) simulations, which can be used in simulations at less accurate level after scaling up the size. The effective potentials are obtained by applying the inverse Monte Carlo (IMC) method [A. P. Lyubartsev and A. Laaksonen, Phys. Rev. E 52(4), 3730-3737 (1995)] on a chosen subset of degrees of freedom described in terms of radial distribution functions. An in-house software package MagiC is developed to obtain the effective potentials for arbitrary molecular systems. In this work we compute effective potentials to model DNA-protein interactions (bacterial LiaR regulator bound to a 26 base pairs DNA fragment) at physiological salt concentration at a coarse-grained (CG) level. Normally the IMC CG pair-potentials are used directly as look-up tables but here we have fitted them to five Gaussians and a repulsive wall. Results show stable association between DNA and the model protein as well as similar position fluctuation profile.
2. Shock Simulations of Single-Site Coarse-Grain RDX using the Dissipative Particle Dynamics Method with Reactivity
Sellers, Michael; Lisal, Martin; Schweigert, Igor; Larentzos, James; Brennan, John
2015-06-01
In discrete particle simulations, when an atomistic model is coarse-grained, a trade-off is made: a boost in computational speed for a reduction in accuracy. Dissipative Particle Dynamics (DPD) methods help to recover accuracy in viscous and thermal properties, while giving back a small amount of computational speed. One of the most notable extensions of DPD has been the introduction of chemical reactivity, called DPD-RX. Today, pairing the current evolution of DPD-RX with a coarse-grained potential and its chemical decomposition reactions allows for the simulation of the shock behavior of energetic materials at a timescale faster than an atomistic counterpart. In 2007, Maillet et al. introduced implicit chemical reactivity in DPD through the concept of particle reactors and simulated the decomposition of liquid nitromethane. We have recently extended the DPD-RX method and have applied it to solid hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) under shock conditions using a recently developed single-site coarse-grain model and a reduced RDX decomposition mechanism. A description of the methods used to simulate RDX and its tranition to hot product gases within DPD-RX will be presented. Additionally, examples of the effect of microstructure on shock behavior will be shown. Approved for public release. Distribution is unlimited.
3. Aggregation of alpha-synuclein by a coarse-grained Monte Carlo simulation
Farmer, Barry; Pandey, Ras
Alpha-synuclein, an intrinsic protein abundant in neurons, is believed to be a major cause of neurodegenerative diseases (e.g. Alzheimer, Parkinson's disease). Abnormal aggregation of ASN leads to Lewy bodies with specific morphologies. We investigate the self-organizing structures in a crowded environment of ASN proteins by a coarse-grained Monte Carlo simulation. ASN is a chain of 140 residues. Structure detail of residues is neglected but its specificity is captured via unique knowledge-based residue-residue interactions. Large-scale simulations are performed to analyze a number local and global physical quantities (e.g. mobility profile, contact map, radius of gyration, structure factor) as a function of temperature and protein concentration. Trend in multi-scale structural variations of the protein in a crowded environment is compared with that of a free protein chain.
4. A Coarse-Grained Model for Simulating Chitosan Hydrogels
Xu, Hongcheng; Matysiak, Silvina
Hydrogels are biologically-derived materials composed of water-filled cross-linking polymer chains. It has widely been used as biodegradable material and has many applications in medical devices. The chitosan hydrogel is stimuli-responsive for undergoing pH-sensitive self-assembly process, allowing programmable tuning of the chitosan deposition through electric pulse. To explore the self-assembly mechanism of chitosan hydroge, we have developed an explicit-solvent coarse-grained chitosan model that has roots in the MARTINI force field, and the pH change is modeled by protonating chitosan chains using the Henderson-Hasselbalch equation. The mechanism of hydrogel network formation will be presented. The self-assembled polymer network qualitatively reproduce many experimental observables such as the pH-dependent strain-stress curve, bulk moduli, and structure factor. Our model is also capable of simulating other similar polyelectrolyte polymer systems.
5. Coarse-grained theory of a realistic tetrahedral liquid model
Procaccia, I.; Regev, I.
2012-02-01
Tetrahedral liquids such as water and silica-melt show unusual thermodynamic behavior such as a density maximum and an increase in specific heat when cooled to low temperatures. Previous work had shown that Monte Carlo and mean-field solutions of a lattice model can exhibit these anomalous properties with or without a phase transition, depending on the values of the different terms in the Hamiltonian. Here we use a somewhat different approach, where we start from a very popular empirical model of tetrahedral liquids —the Stillinger-Weber model— and construct a coarse-grained theory which directly quantifies the local structure of the liquid as a function of volume and temperature. We compare the theory to molecular-dynamics simulations and show that the theory can rationalize the simulation results and the anomalous behavior.
6. Coarse-grained kinetic equations for quantum systems
Petrov, E. G.
2013-01-01
The nonequilibrium density matrix method is employed to derive a master equation for the averaged state populations of an open quantum system subjected to an external high frequency stochastic field. It is shown that if the characteristic time τstoch of the stochastic process is much lower than the characteristic time τsteady of the establishment of the system steady state populations, then on the time scale Δ t ˜ τsteady, the evolution of the system populations can be described by the coarse-grained kinetic equations with the averaged transition rates. As an example, the exact averaging is carried out for the dichotomous Markov process of the kangaroo type.
7. Exact dynamical coarse-graining without time-scale separation
Lu, Jianfeng; Vanden-Eijnden, Eric
2014-07-01
A family of collective variables is proposed to perform exact dynamical coarse-graining even in systems without time scale separation. More precisely, it is shown that these variables are not slow in general, yet satisfy an overdamped Langevin equation that statistically preserves the sequence in which any regions in collective variable space are visited and permits to calculate exactly the mean first passage times from any such region to another. The role of the free energy and diffusion coefficient in this overdamped Langevin equation is discussed, along with the way they transform under any change of variable in collective variable space. These results apply both to systems with and without inertia, and they can be generalized to using several collective variables simultaneously. The view they offer on what makes collective variables and reaction coordinates optimal breaks from the standard notion that good collective variable must be slow variable, and it suggests new ways to interpret data from molecular dynamics simulations and experiments.
8. Coarse-grained molecular simulations of membrane adhesion domains
2014-07-01
We use a coarse-grained molecular model of supported lipid bilayers to study the formation of adhesion domains. We find that this process is a first order phase transition, triggered by a combination of pairwise short range attractive interactions between the adhesion bonds and many-body Casimir-like interactions, mediated by the membrane thermal undulations. The simulation results display an excellent agreement with the recently proposed Weil-Farago two-dimensional lattice model, in which the occupied and empty sites represent, respectively, the adhesion bonds and unbound segments of the membrane. A second phase transition, into a hexatic phase, is observed when the attraction between the adhesion bonds is further strengthened.
9. A coarse-grained model to study calcium activation of the cardiac thin filament
Zhang, Jing; Schwartz, Steven
2015-03-01
Familial hypertrophic cardiomyopathy (FHC) is one of the most common heart disease caused by genetic mutations. Cardiac muscle contraction and relaxation involve regulation of crossbridge binding to the cardiac thin filament, which regulates actomyosin interactions through calcium-dependent alterations in the dynamics of cardiac troponin (cTn) and tropomyosin (Tm). An atomistic model of cTn complex interacting with Tm has been studied by our group. A more realistic model requires the inclusion of the dynamics of actin filament, which is almost 6 times larger than cTn and Tm in terms of atom numbers, and extensive sampling of the model becomes very resource-demanding. By using physics-based protein united-residue force field, we introduce a coarse-grained model to study the calcium activation of the thin filament resulting from cTn's allosteric regulation of Tm dynamics on actin. The time scale is much longer than that of all-atom molecular dynamics simulation because of the reduction of the degrees of freedom. The coarse-grained model is a good template for studying cardiac thin filament mutations that cause FHC, and reduces the cost of computational resources.
10. Classical predictability and coarse-grained evolution of the quantum baker's map
SciTech Connect
Scherer, Artur; Soklakov, Andrei N.; Schack, Ruediger
2006-06-15
We investigate how classical predictability of the coarse-grained evolution of the quantum baker's map depends on the character of the coarse-graining. Our analysis extends earlier work by Brun and Hartle [Phys. Rev. D 60, 123503 (1999)] to the case of a chaotic map. To quantify predictability, we compare the rate of entropy increase for a family of coarse-grainings in the decoherent histories formalism. We find that the rate of entropy increase is dominated by the number of scales characterizing the coarse-graining.
11. Relative entropy and optimization-driven coarse-graining methods in VOTCA
SciTech Connect
Mashayak, S. Y.; Jochum, Mara N.; Koschke, Konstantin; Aluru, N. R.; Rühle, Victor; Junghans, Christoph; Huang, Xuhui
2015-07-20
We discuss recent advances of the VOTCA package for systematic coarse-graining. Two methods have been implemented, namely the downhill simplex optimization and the relative entropy minimization. We illustrate the new methods by coarse-graining SPC/E bulk water and more complex water-methanol mixture systems. The CG potentials obtained from both methods are then evaluated by comparing the pair distributions from the coarse-grained to the reference atomistic simulations.We have also added a parallel analysis framework to improve the computational efficiency of the coarse-graining process.
12. Relative Entropy and Optimization-Driven Coarse-Graining Methods in VOTCA
PubMed Central
Mashayak, S. Y.; Jochum, Mara N.; Koschke, Konstantin; Aluru, N. R.; Rühle, Victor; Junghans, Christoph
2015-01-01
We discuss recent advances of the VOTCA package for systematic coarse-graining. Two methods have been implemented, namely the downhill simplex optimization and the relative entropy minimization. We illustrate the new methods by coarse-graining SPC/E bulk water and more complex water-methanol mixture systems. The CG potentials obtained from both methods are then evaluated by comparing the pair distributions from the coarse-grained to the reference atomistic simulations. In addition to the newly implemented methods, we have also added a parallel analysis framework to improve the computational efficiency of the coarse-graining process. PMID:26192992
13. Atomistic and Coarse Grain Topologies for the Cofactors Associated with the Photosystem II Core Complex.
PubMed
de Jong, Djurre H; Liguori, Nicoletta; van den Berg, Tom; Arnarez, Clement; Periole, Xavier; Marrink, Siewert J
2015-06-25
Electron transfers within and between protein complexes are core processes of the electron transport chains occurring in thylakoid (chloroplast), mitochondrial, and bacterial membranes. These electron transfers involve a number of cofactors. Here we describe the derivation of molecular mechanics parameters for the cofactors associated with the function of the photosystem II core complex: plastoquinone, plastoquinol, heme b, chlorophyll A, pheophytin, and β-carotene. Parameters were also obtained for ubiquinol and ubiquinone, related cofactors involved in the respiratory chain. Parameters were derived at both atomistic and coarse grain (CG) resolutions, compatible with the building blocks of the GROMOS united-atom and Martini CG force fields, respectively. Structural and thermodynamic properties of the cofactors were compared to experimental values when available. The topologies were further tested in molecular dynamics simulations of the cofactors in their physiological environment, e.g., either in a lipid membrane environment or in complex with the heme binding protein bacterioferritin.
14. Coarse-Grained Molecular Models of Water: A Review
PubMed Central
2012-01-01
Coarse-grained (CG) models have proven to be very effective tools in the study of phenomena or systems that involve large time- and length-scales. By decreasing the degrees of freedom in the system and using softer interactions than seen in atomistic models, larger timesteps can be used and much longer simulation times can be studied. CG simulations are widely used to study systems of biological importance that are beyond the reach of atomistic simulation, necessitating a computationally efficient and accurate CG model for water. In this review, we discuss the methods used for developing CG water models and the relative advantages and disadvantages of the resulting models. In general, CG water models differ with regards to how many waters each CG group or bead represents, whether analytical or tabular potentials have been used to describe the interactions, and how the model incorporates electrostatic interactions. Finally, how the models are parameterized depends on their application, so, while some are fitted to experimental properties such as surface tension and density, others are fitted to radial distribution functions extracted from atomistic simulations. PMID:22904601
15. Cellulose microfibril formation within a coarse grained molecular dynamics
Nili, Abdolmadjid; Shklyaev, Oleg; Crespi, Vincent; Zhao, Zhen; Zhong, Linghao; CLSF Collaboration
2014-03-01
Cellulose in biomass is mostly in the form of crystalline microfibrils composed of 18 to 36 parallel chains of polymerized glucose monomers. A single chain is produced by cellular machinery (CesA) located on the preliminary cell wall membrane. Information about the nucleation stage can address important questions about intermediate region between cell wall and the fully formed crystalline microfibrils. Very little is known about the transition from isolated chains to protofibrils up to a full microfibril, in contrast to a large body of studies on both CesA and the final crystalline microfibril. In addition to major experimental challenges in studying this transient regime, the length and time scales of microfibril nucleation are inaccessible to atomistic molecular dynamics. We have developed a novel coarse grained model for cellulose microfibrils which accounts for anisotropic interchain interactions. The model allows us to study nucleation, kinetics, and growth of cellulose chains/protofibrils/microfibrils. This work is supported by the US Department of Energy, Office of Basic Energy Sciences as part of The Center for LignoCellulose Structure and Formation, an Energy Frontier Research Center.
16. Nanodomained Nickel Unite Nanocrystal Strength with Coarse-Grain Ductility
PubMed Central
Wu, Xiaolei; Yuan, Fuping; Yang, Muxin; Jiang, Ping; Zhang, Chuanxin; Chen, Liu; Wei, Yueguang; Ma, Evan
2015-01-01
Conventional metals are routinely hardened by grain refinement or by cold working with the expense of their ductility. Recent nanostructuring strategies have attempted to evade this strength versus ductility trade-off, but the paradox persists. It has never been possible to combine the strength reachable in nanocrystalline metals with the large uniform tensile elongation characteristic of coarse-grained metals. Here a defect engineering strategy on the nanoscale is architected to approach this ultimate combination. For Nickel, spread-out nanoscale domains (average 7 nm in diameter) were produced during electrodeposition, occupying only ~2.4% of the total volume. Yet the resulting Ni achieves a yield strength approaching 1.3 GPa, on par with the strength for nanocrystalline Ni with uniform grains. Simultaneously, the material exhibits a uniform elongation as large as ~30%, at the same level of ductile face-centered-cubic metals. Electron microscopy observations and molecular dynamics simulations demonstrate that the nanoscale domains effectively block dislocations, akin to the role of precipitates for Orowan hardening. In the meantime, the abundant domain boundaries provide dislocation sources and trapping sites of running dislocations for dislocation multiplication, and the ample space in the grain interior allows dislocation storage; a pronounced strain-hardening rate is therefore sustained to enable large uniform elongation. PMID:26122728
17. Perspective: Coarse-grained models for biomolecular systems
Noid, W. G.
2013-09-01
By focusing on essential features, while averaging over less important details, coarse-grained (CG) models provide significant computational and conceptual advantages with respect to more detailed models. Consequently, despite dramatic advances in computational methodologies and resources, CG models enjoy surging popularity and are becoming increasingly equal partners to atomically detailed models. This perspective surveys the rapidly developing landscape of CG models for biomolecular systems. In particular, this review seeks to provide a balanced, coherent, and unified presentation of several distinct approaches for developing CG models, including top-down, network-based, native-centric, knowledge-based, and bottom-up modeling strategies. The review summarizes their basic philosophies, theoretical foundations, typical applications, and recent developments. Additionally, the review identifies fundamental inter-relationships among the diverse approaches and discusses outstanding challenges in the field. When carefully applied and assessed, current CG models provide highly efficient means for investigating the biological consequences of basic physicochemical principles. Moreover, rigorous bottom-up approaches hold great promise for further improving the accuracy and scope of CG models for biomolecular systems.
18. Coarse-grained, foldable, physical model of the polypeptide chain
PubMed Central
Chakraborty, Promita; Zuckermann, Ronald N.
2013-01-01
Although nonflexible, scaled molecular models like Pauling–Corey’s and its descendants have made significant contributions in structural biology research and pedagogy, recent technical advances in 3D printing and electronics make it possible to go one step further in designing physical models of biomacromolecules: to make them conformationally dynamic. We report here the design, construction, and validation of a flexible, scaled, physical model of the polypeptide chain, which accurately reproduces the bond rotational degrees of freedom in the peptide backbone. The coarse-grained backbone model consists of repeating amide and α-carbon units, connected by mechanical bonds (corresponding to φ and ψ) that include realistic barriers to rotation that closely approximate those found at the molecular scale. Longer-range hydrogen-bonding interactions are also incorporated, allowing the chain to readily fold into stable secondary structures. The model is easily constructed with readily obtainable parts and promises to be a tremendous educational aid to the intuitive understanding of chain folding as the basis for macromolecular structure. Furthermore, this physical model can serve as the basis for linking tangible biomacromolecular models directly to the vast array of existing computational tools to provide an enhanced and interactive human–computer interface. PMID:23898168
19. Coarse-grained potentials of single-walled carbon nanotubes
Zhao, Junhua; Jiang, Jin-Wu; Wang, Lifeng; Guo, Wanlin; Rabczuk, Timon
2014-11-01
We develop the coarse-grained (CG) potentials of single-walled carbon nanotubes (SWCNTs) in CNT bundles and buckypaper for the study of the static and dynamic behaviors. The explicit expressions of the CG stretching, bending and torsion potentials for the nanotubes are obtained by the stick-spiral and the beam models, respectively. The non-bonded CG potentials between two different CG beads are derived from analytical results based on the cohesive energy between two parallel and crossing SWCNTs from the van der Waals interactions. We show that the CG model is applicable to large deformations of complex CNT systems by combining the bonded potentials with non-bonded potentials. Checking against full atom molecular dynamics calculations and our analytical results shows that the present CG potentials have high accuracy. The established CG potentials are used to study the mechanical properties of the CNT bundles and buckypaper efficiently at minor computational cost, which shows great potential for the design of micro- and nanomechanical devices and systems.
20. Multi-blob coarse graining for ring polymer solutions.
PubMed
Narros, Arturo; Likos, Christos N; Moreno, Angel J; Capone, Barbara
2014-12-28
We present a multi-scale molecular modeling of concentrated solutions of unknotted and non-concatenated ring polymers under good solvent conditions. The approach is based on a multi-blob representation of each ring polymer, which is capable of overcoming the shortcomings of single-blob approaches that lose their validity at concentrations exceeding the overlap density of the solution [A. Narros, A. J. Moreno, and C. N. Likos, Soft Matter, 2010, 6, 2435]. By means of a first principles coarse-graining strategy based on analytically determined effective pair potentials between the blobs, computed at zero density, we quantitatively reproduce the single molecule and solution properties of a system with well-defined topological constraints. Detailed comparisons with the underlying, monomer-resolved model demonstrate the validity of our approach, which employs fully transferable pair potentials between connected and unconnected blobs. We demonstrate that the pair structure between the centers of mass of the rings is accurately reproduced by the multi-blob approach, thus opening the way for simulation of arbitrarily long polymers. Finally, we show the importance of the topological constraint of non-concatenation on the structure of the concentrated solution and in particular on the size of the correlation hole and the shrinkage of the rings as melt concentrations are approached.
1. Coarse-Grained Model for Water Involving a Virtual Site.
PubMed
Deng, Mingsen; Shen, Hujun
2016-02-01
In this work, we propose a new coarse-grained (CG) model for water by combining the features of two popular CG water models (BMW and MARTINI models) as well as by adopting a topology similar to that of the TIP4P water model. In this CG model, a CG unit, representing four real water molecules, consists of a virtual site, two positively charged particles, and a van der Waals (vdW) interaction center. Distance constraint is applied to the bonds formed between the vdW interaction center and the positively charged particles. The virtual site, which carries a negative charge, is determined by the locations of the two positively charged particles and the vdW interaction center. For the new CG model of water, we coined the name "CAVS" (charge is attached to a virtual site) due to the involvment of the virtual site. After being tested in molecular dynamic (MD) simulations of bulk water at various time steps, under different temperatures and in different salt (NaCl) concentrations, the CAVS model offers encouraging predictions for some bulk properties of water (such as density, dielectric constant, etc.) when compared to experimental ones. PMID:26747089
2. Nanodomained Nickel Unite Nanocrystal Strength with Coarse-Grain Ductility
Wu, Xiaolei; Yuan, Fuping; Yang, Muxin; Jiang, Ping; Zhang, Chuanxin; Chen, Liu; Wei, Yueguang; Ma, Evan
2015-06-01
Conventional metals are routinely hardened by grain refinement or by cold working with the expense of their ductility. Recent nanostructuring strategies have attempted to evade this strength versus ductility trade-off, but the paradox persists. It has never been possible to combine the strength reachable in nanocrystalline metals with the large uniform tensile elongation characteristic of coarse-grained metals. Here a defect engineering strategy on the nanoscale is architected to approach this ultimate combination. For Nickel, spread-out nanoscale domains (average 7 nm in diameter) were produced during electrodeposition, occupying only ~2.4% of the total volume. Yet the resulting Ni achieves a yield strength approaching 1.3 GPa, on par with the strength for nanocrystalline Ni with uniform grains. Simultaneously, the material exhibits a uniform elongation as large as ~30%, at the same level of ductile face-centered-cubic metals. Electron microscopy observations and molecular dynamics simulations demonstrate that the nanoscale domains effectively block dislocations, akin to the role of precipitates for Orowan hardening. In the meantime, the abundant domain boundaries provide dislocation sources and trapping sites of running dislocations for dislocation multiplication, and the ample space in the grain interior allows dislocation storage; a pronounced strain-hardening rate is therefore sustained to enable large uniform elongation.
3. Nanodomained Nickel Unite Nanocrystal Strength with Coarse-Grain Ductility.
PubMed
Wu, Xiaolei; Yuan, Fuping; Yang, Muxin; Jiang, Ping; Zhang, Chuanxin; Chen, Liu; Wei, Yueguang; Ma, Evan
2015-01-01
Conventional metals are routinely hardened by grain refinement or by cold working with the expense of their ductility. Recent nanostructuring strategies have attempted to evade this strength versus ductility trade-off, but the paradox persists. It has never been possible to combine the strength reachable in nanocrystalline metals with the large uniform tensile elongation characteristic of coarse-grained metals. Here a defect engineering strategy on the nanoscale is architected to approach this ultimate combination. For Nickel, spread-out nanoscale domains (average 7 nm in diameter) were produced during electrodeposition, occupying only ~2.4% of the total volume. Yet the resulting Ni achieves a yield strength approaching 1.3 GPa, on par with the strength for nanocrystalline Ni with uniform grains. Simultaneously, the material exhibits a uniform elongation as large as ~30%, at the same level of ductile face-centered-cubic metals. Electron microscopy observations and molecular dynamics simulations demonstrate that the nanoscale domains effectively block dislocations, akin to the role of precipitates for Orowan hardening. In the meantime, the abundant domain boundaries provide dislocation sources and trapping sites of running dislocations for dislocation multiplication, and the ample space in the grain interior allows dislocation storage; a pronounced strain-hardening rate is therefore sustained to enable large uniform elongation. PMID:26122728
4. Coarse-grained simulation reveals key features of HIV-1 capsid self-assembly
Grime, John M. A.; Dama, James F.; Ganser-Pornillos, Barbie K.; Woodward, Cora L.; Jensen, Grant J.; Yeager, Mark; Voth, Gregory A.
2016-05-01
The maturation of HIV-1 viral particles is essential for viral infectivity. During maturation, many copies of the capsid protein (CA) self-assemble into a capsid shell to enclose the viral RNA. The mechanistic details of the initiation and early stages of capsid assembly remain to be delineated. We present coarse-grained simulations of capsid assembly under various conditions, considering not only capsid lattice self-assembly but also the potential disassembly of capsid upon delivery to the cytoplasm of a target cell. The effects of CA concentration, molecular crowding, and the conformational variability of CA are described, with results indicating that capsid nucleation and growth is a multi-stage process requiring well-defined metastable intermediates. Generation of the mature capsid lattice is sensitive to local conditions, with relatively subtle changes in CA concentration and molecular crowding influencing self-assembly and the ensemble of structural morphologies.
5. Coarse-grained simulation reveals key features of HIV-1 capsid self-assembly
PubMed Central
Grime, John M. A.; Dama, James F.; Ganser-Pornillos, Barbie K.; Woodward, Cora L.; Jensen, Grant J.; Yeager, Mark; Voth, Gregory A.
2016-01-01
The maturation of HIV-1 viral particles is essential for viral infectivity. During maturation, many copies of the capsid protein (CA) self-assemble into a capsid shell to enclose the viral RNA. The mechanistic details of the initiation and early stages of capsid assembly remain to be delineated. We present coarse-grained simulations of capsid assembly under various conditions, considering not only capsid lattice self-assembly but also the potential disassembly of capsid upon delivery to the cytoplasm of a target cell. The effects of CA concentration, molecular crowding, and the conformational variability of CA are described, with results indicating that capsid nucleation and growth is a multi-stage process requiring well-defined metastable intermediates. Generation of the mature capsid lattice is sensitive to local conditions, with relatively subtle changes in CA concentration and molecular crowding influencing self-assembly and the ensemble of structural morphologies. PMID:27174390
6. Coarse grained molecular dynamics simulation of nanoconfined water.
PubMed
Eslami, Hossein; Jaafari, Bahram; Mehdipour, Nargess
2013-04-01
A coarse-grained (CG) model for the simulation of nanoconfined water between graphene surfaces is developed. For this purpose, mixed-grained simulations are done, in which the two-site water model of Riniker and van Gunsteren [S. Riniker, W. F. van Gunsteren, J. Chem. Phys. 2011, 134, 084110] is simulated between atomistically resolved graphene surfaces. In the developed pure CG model, the two interaction sites of water and a combination of eight carbon atoms in the graphene surface are grouped together to construct water and surface CG beads. The pure CG potentials are constructed by iteratively matching the radial distribution functions and the density profiles of water beads in the pore with the corresponding mixed-grained distributions. The constructed potentials are shown to be pore-size transferable, capable of predicting structural properties of confined water over the whole range of pore sizes, ranging from extremely narrow pores to bulk water. The model is used to simulate a number of nanoconfined systems of a variety of pore sizes at constant temperature, constant parallel component of pressure, and constant surface area of the confining surfaces. The model is shown to predict the layering of water in contact with the surfaces, and the solvation force is in complete agreement with the mixed-grained model. It is shown that water molecules in the pore have smaller parallel diffusion coefficients compared to bulk water. Well-organized layers beside the surfaces are shown to have lower diffusion coefficients than diffuse layers. More information on the dynamics of water in the pore is obtained by calculating the rate of water exchange between slabs parallel to the surfaces. The time scale to achieve equilibrium for this process, depending on the pore width and on the degree of layering of water beside the surfaces, is a few nanoseconds in nanometric pores.
7. Coarse-grained DNA modeling: Hybridization and ionic effects
Hinckley, Daniel M.
Deoxyribonucleic acid (DNA) is a biopolymer of enormous significance in living systems. The utility of DNA in such systems is derived from the programmable nature of DNA and its unique mechanical properties. Recently, material scientists have harnessed these properties in order to create systems that spontaneous self-assemble on the nanoscale. Both biologists and material scientists are hindered by an incomplete understanding of the physical interactions that together govern DNA's behavior. Computer simulations, especially those at the coarse-grained (CG) level, can potentially complete this understanding by resolving details indiscernible with current experimental techniques. In this thesis, we advance the state-of-the-art of DNA CG simulations by first reviewing the relevant theory and the evolution of CG DNA models since their inception. Then we present 3SPN.2, an improved CG model for DNA that should provide new insights into biological and nanotechnological systems which incorporate DNA. We perform forward flux sampling simulations in order to examine the effect of sequence, oligomer length, and ionic strength on DNA oligomer hybridization. Due to the limitations inherent in continuum treatments of electrostatic interactions in biological systems, we generate a CG model of biological ions for use with 3SPN.2 and other CG models. Lastly, we illustrate the potential of 3SPN.2 and CG ions by using the models in simulations of viral capsid packaging experiments. The models and results described in this thesis will be useful in future modeling efforts that seek to identify the fundamental physics that govern behavior such as nucleosome positioning, DNA hybridization, and DNA nanoassembly.
8. Comparing normal modes across different models and scales: Hessian reduction versus coarse-graining.
PubMed
Ghysels, An; Miller, Benjamin T; Pickard, Frank C; Brooks, Bernard R
2012-10-30
Dimension reduction is often necessary when attempting to reach longer length and time scales in molecular simulations. It is realized by constraining degrees of freedom or by coarse-graining the system. When evaluating the accuracy of a dimensional reduction, there is a practical challenge: the models yield vectors with different lengths, making a comparison by calculating their dot product impossible. This article investigates mapping procedures for normal mode analysis. We first review a horizontal mapping procedure for the reduced Hessian techniques, which projects out degrees of freedom. We then design a vertical mapping procedure for the "implosion" of the all-atom (AA) Hessian to a coarse-grained scale that is based upon vibrational subsystem analysis. This latter method derives both effective force constants and an effective kinetic tensor. Next, a series of metrics is presented for comparison across different scales, where special attention is given to proper mass-weighting. The dimension-dependent metrics, which require prior mapping for proper evaluation, are frequencies, overlap of normal mode vectors, probability similarity, Hessian similarity, collectivity of modes, and thermal fluctuations. The dimension-independent metrics are shape derivatives, elastic modulus, vibrational free energy differences, heat capacity, and projection on a predefined basis set. The power of these metrics to distinguish between reasonable and unreasonable models is tested on a toy alpha helix system and a globular protein; both are represented at several scales: the AA scale, a Gō-like model, a canonical elastic network model, and a network model with intentionally unphysical force constants.
9. STOCK: Structure mapper and online coarse-graining kit for molecular simulations
DOE PAGESBeta
Bevc, Staš; Junghans, Christoph; Praprotnik, Matej
2015-03-15
We present a web toolkit STructure mapper and Online Coarse-graining Kit for setting up coarse-grained molecular simulations. The kit consists of two tools: structure mapping and Boltzmann inversion tools. The aim of the first tool is to define a molecular mapping from high, e.g. all-atom, to low, i.e. coarse-grained, resolution. Using a graphical user interface it generates input files, which are compatible with standard coarse-graining packages, e.g. VOTCA and DL_CGMAP. Our second tool generates effective potentials for coarse-grained simulations preserving the structural properties, e.g. radial distribution functions, of the underlying higher resolution model. The required distribution functions can be providedmore » by any simulation package. Simulations are performed on a local machine and only the distributions are uploaded to the server. The applicability of the toolkit is validated by mapping atomistic pentane and polyalanine molecules to a coarse-grained representation. Effective potentials are derived for systems of TIP3P (transferable intermolecular potential 3 point) water molecules and salt solution. The presented coarse-graining web toolkit is available at http://stock.cmm.ki.si.« less
10. STOCK: Structure mapper and online coarse-graining kit for molecular simulations
SciTech Connect
Bevc, Staš; Junghans, Christoph; Praprotnik, Matej
2015-03-15
We present a web toolkit STructure mapper and Online Coarse-graining Kit for setting up coarse-grained molecular simulations. The kit consists of two tools: structure mapping and Boltzmann inversion tools. The aim of the first tool is to define a molecular mapping from high, e.g. all-atom, to low, i.e. coarse-grained, resolution. Using a graphical user interface it generates input files, which are compatible with standard coarse-graining packages, e.g. VOTCA and DL_CGMAP. Our second tool generates effective potentials for coarse-grained simulations preserving the structural properties, e.g. radial distribution functions, of the underlying higher resolution model. The required distribution functions can be provided by any simulation package. Simulations are performed on a local machine and only the distributions are uploaded to the server. The applicability of the toolkit is validated by mapping atomistic pentane and polyalanine molecules to a coarse-grained representation. Effective potentials are derived for systems of TIP3P (transferable intermolecular potential 3 point) water molecules and salt solution. The presented coarse-graining web toolkit is available at http://stock.cmm.ki.si.
11. Evaluation of coarse-grained mapping schemes for polysaccharide chains in cellulose
Markutsya, Sergiy; Devarajan, Ajitha; Baluyut, John Y.; Windus, Theresa L.; Gordon, Mark S.; Lamm, Monica H.
2013-06-01
A fundamental understanding of the intermolecular forces that bind polysaccharide chains together in cellulose is crucial for designing efficient methods to overcome the recalcitrance of lignocellulosic biomass to hydrolysis. Because the characteristic time and length scales for the degradation of cellulose by enzymatic hydrolysis or chemical pretreatment span orders of magnitude, it is important to closely integrate the molecular models used at each scale so that, ultimately, one may switch seamlessly between quantum, atomistic, and coarse-grained descriptions of the system. As a step towards that goal, four multiscale coarse-grained models for polysaccharide chains in a cellulose-Iα microfiber are considered. Using the force matching method, effective coarse-grained forces are derived from all-atom trajectories. Performance of the coarse-grained models is evaluated by comparing the intrachain radial distribution functions with those obtained using the all-atom reference data. The all-atom simulation reveals a double peak in the radial distribution function for sites within each glucose residue that arises from the distinct conformations sampled by the primary alcohol group in the glucose residues. The three-site and four-site coarse-grained models have sufficient degrees of freedom to predict this double peak while the one-site and two-site models do not. This is the first time that coarse-grained models have been shown to reproduce such subtle, yet important, molecular features in a polysaccharide chain. The relative orientations between glucose residues along the polysaccharide chain are evaluated and it is found that the four-site coarse-grained model is best at reproducing the glucose-glucose conformations observed in the all-atom simulation. The success of the four-site coarse-grained model underscores the importance of decoupling the pyranose ring from the oxygen atom in the glycosidic bond when developing all-atom to coarse-grained mapping schemes for
12. First-principle approach to rescale the dynamics of simulated coarse-grained macromolecular liquids
Lyubimov, I.; Guenza, M. G.
2011-09-01
We present a detailed derivation and testing of our approach to rescale the dynamics of mesoscale simulations of coarse-grained polymer melts (I. Y. Lyubimov, J. McCarty, A. Clark, and M. G. Guenza, J. Chem. Phys.JCPSA60021-960610.1063/1.3450301 132, 224903 (2010)). Starting from the first-principle Liouville equation and applying the Mori-Zwanzig projection operator technique, we derive the generalized Langevin equations (GLEs) for the coarse-grained representations of the liquid. The chosen slow variables in the projection operators define the length scale of coarse graining. Each polymer is represented at two levels of coarse graining: monomeric as a bead-and-spring model and molecular as a soft colloid. In the long-time regime where the center-of-mass follows Brownian motion and the internal dynamics is completely relaxed, the two descriptions must be equivalent. By enforcing this formal relation we derive from the GLEs the analytical rescaling factors to be applied to dynamical data in the coarse-grained representation to recover the monomeric description. Change in entropy and change in friction are the two corrections to be accounted for to compensate the effects of coarse graining on the polymer dynamics. The solution of the memory functions in the coarse-grained representations provides the dynamical rescaling of the friction coefficient. The calculation of the internal degrees of freedom provides the correction of the change in entropy due to coarse graining. The resulting rescaling formalism is a function of the coarse-grained model and thermodynamic parameters of the system simulated. The rescaled dynamics obtained from mesoscale simulations of polyethylene, represented as soft-colloidal particles, by applying our rescaling approach shows a good agreement with data of translational diffusion measured experimentally and from simulations. The proposed method is used to predict self-diffusion coefficients of new polyethylene samples.
13. A combined coarse-grained and all-atom simulation of TRPV1 channel gating and heat activation
PubMed Central
Qin, Feng
2015-01-01
The transient receptor potential (TRP) channels act as key sensors of various chemical and physical stimuli in eukaryotic cells. Despite years of study, the molecular mechanisms of TRP channel activation remain unclear. To elucidate the structural, dynamic, and energetic basis of gating in TRPV1 (a founding member of the TRPV subfamily), we performed coarse-grained modeling and all-atom molecular dynamics (MD) simulation based on the recently solved high resolution structures of the open and closed form of TRPV1. Our coarse-grained normal mode analysis captures two key modes of collective motions involved in the TRPV1 gating transition, featuring a quaternary twist motion of the transmembrane domains (TMDs) relative to the intracellular domains (ICDs). Our transition pathway modeling predicts a sequence of structural movements that propagate from the ICDs to the TMDs via key interface domains (including the membrane proximal domain and the C-terminal domain), leading to sequential opening of the selectivity filter followed by the lower gate in the channel pore (confirmed by modeling conformational changes induced by the activation of ICDs). The above findings of coarse-grained modeling are robust to perturbation by lipids. Finally, our MD simulation of the ICD identifies key residues that contribute differently to the nonpolar energy of the open and closed state, and these residues are predicted to control the temperature sensitivity of TRPV1 gating. These computational predictions offer new insights to the mechanism for heat activation of TRPV1 gating, and will guide our future electrophysiology and mutagenesis studies. PMID:25918362
14. Microscopic derivation of particle-based coarse-grained dynamics
Izvekov, Sergei
2013-04-01
In this paper we revisit the derivation of equations of motion for coarse-grained (CG) particles from the microscopic Hamiltonian dynamics of the underlying atomistic system in equilibrium. The derivation is based on the projection operator method and time-convolution equation. We demonstrate that due to the energy exchange between CG and intraparticle phase space coordinates in the microscopic system, the choice of projection operator is not unique, leading to different CG equations of motion that have the form of the nonlinear generalized Langevin equation (GLE). We derive the idempotence properties for the projection operators along the system trajectories and show that these properties result in streaming terms of the respective GLEs that are conservative forces and allow the expression of the non-conservative forces explicitly through thermodynamic averages, which can be measured from the microscopic simulations. The difference between GLEs that are presented herein lies in how the non-conservative forces are partitioned into dissipative and projected contributions. We compute the projected force and analyze conditions under which the projected (stochastic) force is orthogonal to (uncorrelated with) the momenta of CG particles, therefore justifying a transition to a framework of stochastic differential equations. We show that a position- and momentum-independent memory function appears only if the projected force is fully decoupled from the past CG positions and momenta, respectively. In the case of non-vanishing correlations between the projected force and the CG coordinates in past times, we derive explicitly the position- and momentum-dependent memory function in a form of projection onto a space spanned by N-order Hermite polynomials. The expressions presented herein can be used to construct a hierarchy of thermodynamically consistent CG models with momentum-dependent memory functions. They can also be used to design computational schemes for obtaining the
15. Coarse graining the distribution function of cold dark matter - II
Henriksen, R. N.
2004-12-01
We study analytically the coarse- and fine-grained distribution function (DF) established by the self-similar infall of collisionless matter. We find this function explicitly for isotropic and spherically symmetric systems in terms of cosmological initial conditions. The coarse-grained function is structureless and steady but the familiar phase-space sheet substructure is recovered in the fine-grained limit. By breaking the self-similarity of the halo infall we are able to argue for a central density flattening. In addition there will be an edge steepening. The best-fitting analytic density function is likely to be provided by a high-order polytrope fit smoothly to an outer power law of index -3 for isolated systems. There may be a transition to a -4 power law in the outer regions of tidally truncated systems. As we find that the central flattening is progressive in time, dynamically young systems such as galaxy clusters may well possess a Navarro, Frenk and White type density profile, while primordial dwarf galaxies, for example, are expected to have cores. This progressive flattening is expected to end either in the non-singular isothermal sphere, or in the non-singular metastable polytropic cores; as the DFs associated with each of these arise naturally in the bulk halo during the infall. We suggest, based on previous studies of the evolution of de-stabilized polytropes, that a collisionless system may pass through a family of polytropes of increasing order, finally approaching the limit of the non-singular isothermal sphere, if the violent' collective relaxation is frequently re-excited by merger' events. Thus central dominant (cD) galaxies, and indeed all bright galaxies that have grown in this fashion, should be in polytropic states. Our results suggest that no physics beyond that of wave-particle scattering is necessary to explain the nature of dark matter density profiles. However, this may be assisted by the scattering of particles from the centre of the
16. Microscopic derivation of particle-based coarse-grained dynamics.
PubMed
Izvekov, Sergei
2013-04-01
In this paper we revisit the derivation of equations of motion for coarse-grained (CG) particles from the microscopic Hamiltonian dynamics of the underlying atomistic system in equilibrium. The derivation is based on the projection operator method and time-convolution equation. We demonstrate that due to the energy exchange between CG and intraparticle phase space coordinates in the microscopic system, the choice of projection operator is not unique, leading to different CG equations of motion that have the form of the nonlinear generalized Langevin equation (GLE). We derive the idempotence properties for the projection operators along the system trajectories and show that these properties result in streaming terms of the respective GLEs that are conservative forces and allow the expression of the non-conservative forces explicitly through thermodynamic averages, which can be measured from the microscopic simulations. The difference between GLEs that are presented herein lies in how the non-conservative forces are partitioned into dissipative and projected contributions. We compute the projected force and analyze conditions under which the projected (stochastic) force is orthogonal to (uncorrelated with) the momenta of CG particles, therefore justifying a transition to a framework of stochastic differential equations. We show that a position- and momentum-independent memory function appears only if the projected force is fully decoupled from the past CG positions and momenta, respectively. In the case of non-vanishing correlations between the projected force and the CG coordinates in past times, we derive explicitly the position- and momentum-dependent memory function in a form of projection onto a space spanned by N-order Hermite polynomials. The expressions presented herein can be used to construct a hierarchy of thermodynamically consistent CG models with momentum-dependent memory functions. They can also be used to design computational schemes for obtaining the
17. Supra-Atomic Coarse-Grained GROMOS Force Field for Aliphatic Hydrocarbons in the Liquid Phase.
PubMed
Eichenberger, Andreas P; Huang, Wei; Riniker, Sereina; van Gunsteren, Wilfred F
2015-07-14
A supra-atomic coarse-grained (CG) force field for liquid n-alkanes is presented. The model was calibrated using experimental thermodynamic data and structural as well as energetic properties for 14 n-alkanes as obtained from atomistic fine-grained (FG) simulations of the corresponding hydrocarbons using the GROMOS 45A3 biomolecular force field. A variation of the nonbonded force-field parameters obtained from mapping the FG interactions onto the CG degrees of freedom to fit the density and heat of vaporization to experimental values turned out to be mandatory for a correct reproduction of these data by the CG model, while the bonded force-field parameters for the CG model could be obtained from a Boltzmann-weighted fit with some variations with respect to the corresponding properties from the FG simulations mapped onto the CG degrees of freedom. The model presents 6 different CG bead types, for bead sizes from 2 to 4 distinguishing between terminal and nonterminal beads within an alkane chain (end or middle). It contains different nonbonded Lennard-Jones parameters for the interaction of CG alkanes with CG water. The CG alkane model was further tested by comparing predictions of the excess free energy, the self-diffusion constant, surface tension, isothermal compressibility, heat capacity, thermal expansion coefficient, and shear viscosity for n-alkanes to experimental values. The CG model offers a thermodynamically calibrated basis for the development of CG models of lipids.
18. Extension of 239+240Pu sediment geochronology to coarse-grained marine sediments
USGS Publications Warehouse
Kuehl, Steven A.; Ketterer, Michael E.; Miselis, Jennifer L.
2012-01-01
Sediment geochronology of coastal sedimentary environments dominated by sand has been extremely limited because concentrations of natural and bomb-fallout radionuclides are often below the limit of measurement using standard techniques. ICP-MS analyses of 239+240Pu from two sites representative of traditionally challenging (i.e., low concentration) environments provide a "proof of concept" and demonstrate a new application for bomb-fallout radiotracers in the study of sandy shelf-seabed dynamics. A kasten core from the New Zealand shelf in the Southern Hemisphere (low fallout), and a vibracore from the sandy nearshore of North Carolina (low particle surface area) both reveal measurable 239+240Pu activities at depth. In the case of the New Zealand site, independently verified steady-state sedimentation results in a 239+240Pu profile that mimics the expected atmospheric fallout. The depth profile of 239+240Pu in the North Carolina core is more uniform, indicating significant sediment resuspension, which would be expected in this energetic nearshore environment. This study, for the first time, demonstrates the utility of 239+240Pu in the study of sandy environments, significantly extending the application of bomb-fallout isotopes to coarse-grained sediments, which compose the majority of nearshore regions.
19. A principle in dynamic coarse graining-Onsager principle and its applications
Doi, M.
2016-07-01
Dynamic coarse graining is a procedure to map a dynamical system with large degrees of freedom to a system with smaller degrees of freedom by properly choosing coarse grained variables. This procedure has been conducted mainly by empiricisms. In this paper, I will discuss a theoretical principle which may be useful for this procedure. I will discuss how to choose coarse grained variables (or slow variables), and how to set up their evolution equations. To this end, I will review the classical example of dynamic coarse graining, i.e., the Brownian motion theory, and show a variational principle for the evolution of the slow variables. The principle, called the Onsager principle, is useful not only to derive the evolution equations, but also to solve the problems.
20. Cratering Efficiency Reduction due to Armoring on the Coarse-Grained Targets
Tatsumi, E.; Sugita, S.
2015-09-01
Cratering experiments on coarse-grained targets, simulating the surface of rubble-pile asteroids, such as Itokawa. The transfers of energy and momentum on the disruption of the first target grain would model the cratering efficiency reduction.
1. Studying Amphiphilic Self-assembly with Soft Coarse-Grained Models
Müller, Marcus
2011-11-01
Highly coarse-grained models for investigating the self-assembly of lipids and copolymer materials are discussed. Soft interactions between segments that represent many atoms naturally arise in the course of systematic coarse-graining, and they are necessary for modeling fluctuation effects whose strengths is dictated by a large invariant degree of polymerization. The soft non-bonded interactions of the coarse-grained models are related to the excess free-energy functional of an equivalent field-theoretic description. The connection between the particle-based model and the field-theoretic description helps to identify the physical significance of the model interactions. Non-bonded interactions, which describe the complex phase behavior of compressible mixtures or include local fluid-like packing effects of the coarse-grained segments, can be systematically constructed based on liquid-state theory or classical density functional theory. Details of the computational implementation and limitations of soft coarse-grained models are discussed. Two computational techniques—field-theoretic force-matching and umbrella sampling—are devised for computing a free-energy functional from a particle-based description. They can be employed to (i) derive the non-bonded free-energy functional of a soft coarse-grained model from a more detailed computational model or to (ii) derive a field-theoretic description from a particle-based model. Moreover, different strategies for accurately calculating free energies of self-assembled systems are described and selected applications presented.
2. Coarse-graining using the relative entropy and simplex-based optimization methods in VOTCA
Rühle, Victor; Jochum, Mara; Koschke, Konstantin; Aluru, N. R.; Kremer, Kurt; Mashayak, S. Y.; Junghans, Christoph
2014-03-01
Coarse-grained (CG) simulations are an important tool to investigate systems on larger time and length scales. Several methods for systematic coarse-graining were developed, varying in complexity and the property of interest. Thus, the question arises which method best suits a specific class of system and desired application. The Versatile Object-oriented Toolkit for Coarse-graining Applications (VOTCA) provides a uniform platform for coarse-graining methods and allows for their direct comparison. We present recent advances of VOTCA, namely the implementation of the relative entropy method and downhill simplex optimization for coarse-graining. The methods are illustrated by coarse-graining SPC/E bulk water and a water-methanol mixture. Both CG models reproduce the pair distributions accurately. SYM is supported by AFOSR under grant 11157642 and by NSF under grant 1264282. CJ was supported in part by the NSF PHY11-25915 at KITP. K. Koschke acknowledges funding by the Nestle Research Center.
3. Bridging Enzymatic Structure Function via Mechanics: A Coarse-Grain Approach.
PubMed
Sacquin-Mora, S
2016-01-01
Flexibility is a central aspect of protein function, and ligand binding in enzymes involves a wide range of structural changes, ranging from large-scale domain movements to small loop or side-chain rearrangements. In order to understand how the mechanical properties of enzymes, and the mechanical variations that are induced by ligand binding, relate to enzymatic activity, we carried out coarse-grain Brownian dynamics simulations on a set of enzymes whose structures in the unbound and ligand-bound forms are available in the Protein Data Bank. Our results show that enzymes are remarkably heterogeneous objects from a mechanical point of view and that the local rigidity of individual residues is tightly connected to their part in the protein's overall structure and function. The systematic comparison of the rigidity of enzymes in their unbound and bound forms highlights the fact that small conformational changes can induce large mechanical effects, leading to either more or less flexibility depending on the enzyme's architecture and the location of its ligand-biding site. These mechanical variations target a limited number of specific residues that occupy key locations for enzymatic activity, and our approach thus offers a mean to detect perturbation-sensitive sites in enzymes, where the addition or removal of a few interactions will lead to important changes in the proteins internal dynamics. PMID:27497169
4. A coarse-grained model for the simulations of biomolecular interactions in cellular environments
SciTech Connect
Xie, Zhong-Ru; Chen, Jiawen; Wu, Yinghao
2014-02-07
The interactions of bio-molecules constitute the key steps of cellular functions. However, in vivo binding properties differ significantly from their in vitro measurements due to the heterogeneity of cellular environments. Here we introduce a coarse-grained model based on rigid-body representation to study how factors such as cellular crowding and membrane confinement affect molecular binding. The macroscopic parameters such as the equilibrium constant and the kinetic rate constant are calibrated by adjusting the microscopic coefficients used in the numerical simulations. By changing these model parameters that are experimentally approachable, we are able to study the kinetic and thermodynamic properties of molecular binding, as well as the effects caused by specific cellular environments. We investigate the volumetric effects of crowded intracellular space on bio-molecular diffusion and diffusion-limited reactions. Furthermore, the binding constants of membrane proteins are currently difficult to measure. We provide quantitative estimations about how the binding of membrane proteins deviates from soluble proteins under different degrees of membrane confinements. The simulation results provide biological insights to the functions of membrane receptors on cell surfaces. Overall, our studies establish a connection between the details of molecular interactions and the heterogeneity of cellular environments.
5. Improved Coarse-Grained Modeling of Cholesterol-Containing Lipid Bilayers
SciTech Connect
Daily, Michael D.; Olsen, Brett N.; Schlesinger, Paul H.; Ory, Daniel S.; Baker, Nathan A.
2014-03-24
In mammalian cells cholesterol is essential for membrane function, but in excess can be cytototoxic. The cellular response to acute cholesterol loading involves biophysical-based mechanisms that regulate cholesterol levels, through modulation of the “activity” or accessibility of cholesterol to extra-membrane acceptors. Experiments and united atom (UA) simulations show that at high concentrations of cholesterol, lipid bilayers thin significantly and cholesterol availability to external acceptors increases substantially. Such cholesterol activation is critical to its trafficking within cells. Here we aim to reduce the computational cost to enable simulation of large and complex systems involved in cholesterol regulation, such as those including oxysterols and cholesterol-sensing proteins. To accomplish this, we have modified the published MARTINI coarse-grained force field to improve its predictions of cholesterol-induced changes in both macroscopic and microscopic properties of membranes. Most notably, MARTINI fails to capture both the (macroscopic) area condensation and membrane thickening seen at less than 30% cholesterol and the thinning seen above 40% cholesterol. The thinning at high concentration is critical to cholesterol activation. Microscopic properties of interest include cholesterol-cholesterol radial distribution functions (RDFs), tilt angle, and accessible surface area. First, we develop an “angle-corrected” model wherein we modify the coarse-grained bond angle potentials based on atomistic simulations. This modification significantly improves prediction of macroscopic properties, most notably the thickening/thinning behavior, and also slightly improves microscopic property prediction relative to MARTINI. Second, we add to the angle correction a “volume correction” by also adjusting phospholipid bond lengths to achieve a more accurate volume per molecule. The angle + volume correction substantially further improves the quantitative
6. A pressure-transferable coarse-grained potential for modeling the shock Hugoniot of polyethylene
Agrawal, Vipin; Peralta, Pedro; Li, Yiyang; Oswald, Jay
2016-09-01
We investigate the thermomechanical response of semi-crystalline polyethylene under shock compression by performing molecular dynamics (MD) simulations using a new coarse-graining scheme inspired by the embedded atom method. The coarse-graining scheme combines the iterative Boltzmann inversion method and least squares optimization to parameterize interactions between coarse-grained sites, including a many-body potential energy designed to improve the representability of the model across a wide range of thermodynamic states. We demonstrate that a coarse-grained model of polyethylene, calibrated to match target structural and thermodynamic data generated from isothermal MD simulations at different pressures, can also accurately predict the shock Hugoniot response. Analysis of the rise in temperature along the shock Hugoniot and comparison with analytical predictions from the Mie-Grüneisen equation of state are performed to thoroughly explore the thermodynamic consistency of the model. As the coarse-graining model affords nearly two orders of magnitude reduction in simulation time compared to all-atom MD simulations, the proposed model can help identify how nanoscale structure in semi-crystalline polymers, such as polyethylene, influences mechanical behavior under extreme loading.
7. Boltzmann rovibrational collisional coarse-grained model for internal energy excitation and dissociation in hypersonic flows.
PubMed
Munafò, A; Panesi, M; Magin, T E
2014-02-01
A Boltzmann rovibrational collisional coarse-grained model is proposed to reduce a detailed kinetic mechanism database developed at NASA Ames Research Center for internal energy transfer and dissociation in N(2)-N interactions. The coarse-grained model is constructed by lumping the rovibrational energy levels of the N(2) molecule into energy bins. The population of the levels within each bin is assumed to follow a Boltzmann distribution at the local translational temperature. Excitation and dissociation rate coefficients for the energy bins are obtained by averaging the elementary rate coefficients. The energy bins are treated as separate species, thus allowing for non-Boltzmann distributions of their populations. The proposed coarse-grained model is applied to the study of nonequilibrium flows behind normal shock waves and within converging-diverging nozzles. In both cases, the flow is assumed inviscid and steady. Computational results are compared with those obtained by direct solution of the master equation for the rovibrational collisional model and a more conventional multitemperature model. It is found that the proposed coarse-grained model is able to accurately resolve the nonequilibrium dynamics of internal energy excitation and dissociation-recombination processes with only 20 energy bins. Furthermore, the proposed coarse-grained model provides a superior description of the nonequilibrium phenomena occurring in shock heated and nozzle flows when compared with the conventional multitemperature models.
8. A pressure-transferable coarse-grained potential for modeling the shock Hugoniot of polyethylene.
PubMed
Agrawal, Vipin; Peralta, Pedro; Li, Yiyang; Oswald, Jay
2016-09-14
We investigate the thermomechanical response of semi-crystalline polyethylene under shock compression by performing molecular dynamics (MD) simulations using a new coarse-graining scheme inspired by the embedded atom method. The coarse-graining scheme combines the iterative Boltzmann inversion method and least squares optimization to parameterize interactions between coarse-grained sites, including a many-body potential energy designed to improve the representability of the model across a wide range of thermodynamic states. We demonstrate that a coarse-grained model of polyethylene, calibrated to match target structural and thermodynamic data generated from isothermal MD simulations at different pressures, can also accurately predict the shock Hugoniot response. Analysis of the rise in temperature along the shock Hugoniot and comparison with analytical predictions from the Mie-Grüneisen equation of state are performed to thoroughly explore the thermodynamic consistency of the model. As the coarse-graining model affords nearly two orders of magnitude reduction in simulation time compared to all-atom MD simulations, the proposed model can help identify how nanoscale structure in semi-crystalline polymers, such as polyethylene, influences mechanical behavior under extreme loading. PMID:27634275
9. Optimization of an Elastic Network Augmented Coarse Grained Model to Study CCMV Capsid Deformation
PubMed Central
Globisch, Christoph; Krishnamani, Venkatramanan; Deserno, Markus; Peter, Christine
2013-01-01
The major protective coat of most viruses is a highly symmetric protein capsid that forms spontaneously from many copies of identical proteins. Structural and mechanical properties of such capsids, as well as their self-assembly process, have been studied experimentally and theoretically, including modeling efforts by computer simulations on various scales. Atomistic models include specific details of local protein binding but are limited in system size and accessible time, while coarse grained (CG) models do get access to longer time and length scales but often lack the specific local interactions. Multi-scale models aim at bridging this gap by systematically connecting different levels of resolution. Here, a CG model for CCMV (Cowpea Chlorotic Mottle Virus), a virus with an icosahedral shell of 180 identical protein monomers, is developed, where parameters are derived from atomistic simulations of capsid protein dimers in aqueous solution. In particular, a new method is introduced to combine the MARTINI CG model with a supportive elastic network based on structural fluctuations of individual monomers. In the parametrization process, both network connectivity and strength are optimized. This elastic-network optimized CG model, which solely relies on atomistic data of small units (dimers), is able to correctly predict inter-protein conformational flexibility and properties of larger capsid fragments of 20 and more subunits. Furthermore, it is shown that this CG model reproduces experimental (Atomic Force Microscopy) indentation measurements of the entire viral capsid. Thus it is shown that one obvious goal for hierarchical modeling, namely predicting mechanical properties of larger protein complexes from models that are carefully parametrized on elastic properties of smaller units, is achievable. PMID:23613730
10. Spreading of a Unilamellar Liposome on Charged Substrates: A Coarse-Grained Molecular Simulation.
PubMed
Kong, Xian; Lu, Diannan; Wu, Jianzhong; Liu, Zheng
2016-04-19
Supported lipid bilayers (SLBs) are able to accommodate membrane proteins useful for diverse biomimetic applications. Although liposome spreading represents a common procedure for preparation of SLBs, the underlying mechanism is not yet fully understood, particularly from a molecular perspective. The present study examines the effects of the substrate charge on unilamellar liposome spreading on the basis of molecular dynamics simulations for a coarse-grained model of the solvent and lipid molecules. Liposome transformation into a lipid bilayer of different microscopic structures suggests three types of kinetic pathways depending on the substrate charge density, that is, top-receding, parachute, and parachute with wormholes. Each pathway leads to a unique distribution of the lipid molecules and thereby distinctive properties of SLBs. An increase of the substrate charge density results in a magnified asymmetry of the SLBs in terms of the ratio of charged lipids, parallel surface movements, and the distribution of lipid molecules. While the lipid mobility in the proximal layer is strongly correlated with the substrate potential, the dynamics of lipid molecules in the distal monolayer is similar to that of a freestanding lipid bilayer. For liposome spreading on a highly charged surface, wormhole formation promotes lipid exchange between the SLB monolayers thus reduces the asymmetry on the number density of lipid molecules, the lipid order parameter, and the monolayer thickness. The simulation results reveal the important regulatory role of electrostatic interactions on liposome spreading and the properties of SLBs.
11. Spreading of a Unilamellar Liposome on Charged Substrates: A Coarse-Grained Molecular Simulation.
PubMed
Kong, Xian; Lu, Diannan; Wu, Jianzhong; Liu, Zheng
2016-04-19
Supported lipid bilayers (SLBs) are able to accommodate membrane proteins useful for diverse biomimetic applications. Although liposome spreading represents a common procedure for preparation of SLBs, the underlying mechanism is not yet fully understood, particularly from a molecular perspective. The present study examines the effects of the substrate charge on unilamellar liposome spreading on the basis of molecular dynamics simulations for a coarse-grained model of the solvent and lipid molecules. Liposome transformation into a lipid bilayer of different microscopic structures suggests three types of kinetic pathways depending on the substrate charge density, that is, top-receding, parachute, and parachute with wormholes. Each pathway leads to a unique distribution of the lipid molecules and thereby distinctive properties of SLBs. An increase of the substrate charge density results in a magnified asymmetry of the SLBs in terms of the ratio of charged lipids, parallel surface movements, and the distribution of lipid molecules. While the lipid mobility in the proximal layer is strongly correlated with the substrate potential, the dynamics of lipid molecules in the distal monolayer is similar to that of a freestanding lipid bilayer. For liposome spreading on a highly charged surface, wormhole formation promotes lipid exchange between the SLB monolayers thus reduces the asymmetry on the number density of lipid molecules, the lipid order parameter, and the monolayer thickness. The simulation results reveal the important regulatory role of electrostatic interactions on liposome spreading and the properties of SLBs. PMID:27019394
12. PSII-LHCII supercomplex organizations in photosynthetic membrane by coarse-grained simulation.
PubMed
Lee, Cheng-Kuang; Pao, Chun-Wei; Smit, Berend
2015-03-12
Green plant photosystem II (PSII) and light-harvesting complex II (LHCII) in the stacked grana regions of thylakoid membranes can self-organize into various PSII-LHCII supercomplexes with crystalline or fluid-like supramolecular structures to adjust themselves with external stimuli such as high/low light and temperatures, rendering tunable solar light absorption spectrum and photosynthesis efficiencies. However, the mechanisms controlling the PSII-LHCII supercomplex organizations remain elusive. In this work, we constructed a coarse-grained (CG) model of the thylakoid membrane including lipid molecules and a PSII-LHCII supercomplex considering association/dissociation of moderately bound-LHCIIs. The CG interaction between CG beads were constructed based on electron microscope (EM) experimental results, and we were able to simulate the PSII-LHCII supramolecular organization of a 500 × 500 nm(2) thylakoid membrane, which is compatible with experiments. Our CGMD simulations can successfully reproduce order structures of PSII-LHCII supercomplexes under various protein packing fractions, free-LHCII:PSII ratios, and temperatures, thereby providing insights into mechanisms leading to PSII-LHCII supercomplex organizations in photosynthetic membranes.
13. From time series to complex networks: The phase space coarse graining
Wang, Minggang; Tian, Lixin
2016-11-01
In this paper, we present a simple and fast computational method, the phase space coarse graining algorithm that converts a time series into a directed and weighted complex network. The constructed directed and weighted complex network inherits several properties of the series in its structure. Thereby, periodic series convert into regular networks, and random series do so into random networks. Moreover, chaotic series convert into scale-free networks. It is shown that the phase space coarse graining algorithm allows us to distinguish, identify and describe in detail various time series. Finally, we apply the phase space coarse graining algorithm to the practical observations series, international gasoline regular spot price series and identify its dynamic characteristics.
14. Bottom-up coarse-graining of a simple graphene model: the blob picture.
PubMed
Kauzlarić, David; Meier, Julia T; Español, Pep; Succi, Sauro; Greiner, Andreas; Korvink, Jan G
2011-02-14
The coarse-graining of a simple all-atom 2D microscopic model of graphene, in terms of "blobs" described by center of mass variables, is presented. The equations of motion of the coarse-grained variables take the form of dissipative particle dynamics (DPD). The coarse-grained conservative forces and the friction of the DPD model are obtained via a bottom-up procedure from molecular dynamics (MD) simulations. The separation of timescales for blobs of 24 and 96 carbon atoms is sufficiently pronounced for the Markovian assumption, inherent to the DPD model, to provide satisfactory results. In particular, the MD velocity autocorrelation function of the blobs is well reproduced by the DPD model, provided that the effect of friction and noise is taken into account. However, DPD cross-correlations between neighbor blobs show appreciable discrepancies with respect to the MD results. Possible extensions to mend these discrepancies are briefly outlined. PMID:21322660
15. A unified data representation theory for network visualization, ordering and coarse-graining
Kovács, István A.; Mizsei, Réka; Csermely, Péter
2015-09-01
Representation of large data sets became a key question of many scientific disciplines in the last decade. Several approaches for network visualization, data ordering and coarse-graining accomplished this goal. However, there was no underlying theoretical framework linking these problems. Here we show an elegant, information theoretic data representation approach as a unified solution of network visualization, data ordering and coarse-graining. The optimal representation is the hardest to distinguish from the original data matrix, measured by the relative entropy. The representation of network nodes as probability distributions provides an efficient visualization method and, in one dimension, an ordering of network nodes and edges. Coarse-grained representations of the input network enable both efficient data compression and hierarchical visualization to achieve high quality representations of larger data sets. Our unified data representation theory will help the analysis of extensive data sets, by revealing the large-scale structure of complex networks in a comprehensible form.
16. Systematic and simulation-free coarse graining of homopolymer melts: A structure-based study
SciTech Connect
Yang, Delian; Wang, Qiang
2015-02-07
We propose a systematic and simulation-free strategy for coarse graining of homopolymer melts, where each chain of N{sub m} monomers is uniformly divided into N segments, with the spatial position of each segment corresponding to the center-of-mass of its monomers. We use integral-equation theories suitable for the study of equilibrium properties of polymers, instead of many-chain molecular simulations, to obtain the structural and thermodynamic properties of both original and coarse-grained (CG) systems, and quantitatively examine how the effective pair potentials between CG segments and the thermodynamic properties of CG systems vary with N. Our systematic and simulation-free strategy is much faster than those using many-chain simulations, thus effectively solving the transferability problem in coarse graining, and provides the quantitative basis for choosing the appropriate N-values. It also avoids the problems caused by finite-size effects and statistical uncertainties in many-chain simulations. Taking the simple hard-core Gaussian thread model [K. S. Schweizer and J. G. Curro, Chem. Phys. 149, 105 (1990)] as the original system, we demonstrate our strategy applied to structure-based coarse graining, which is quite general and versatile, and compare in detail the various integral-equation theories and closures for coarse graining. Our numerical results show that the effective CG potentials for various N and closures can be collapsed approximately onto the same curve, and that structure-based coarse graining cannot give thermodynamic consistency between original and CG systems at any N < N{sub m}.
17. The impact of resolution upon entropy and information in coarse-grained models
Foley, Thomas T.; Shell, M. Scott; Noid, W. G.
2015-12-01
By eliminating unnecessary degrees of freedom, coarse-grained (CG) models tremendously facilitate numerical calculations and theoretical analyses of complex phenomena. However, their success critically depends upon the representation of the system and the effective potential that governs the CG degrees of freedom. This work investigates the relationship between the CG representation and the many-body potential of mean force (PMF), W, which is the appropriate effective potential for a CG model that exactly preserves the structural and thermodynamic properties of a given high resolution model. In particular, we investigate the entropic component of the PMF and its dependence upon the CG resolution. This entropic component, SW, is a configuration-dependent relative entropy that determines the temperature dependence of W. As a direct consequence of eliminating high resolution details from the CG model, the coarsening process transfers configurational entropy and information from the configuration space into SW. In order to further investigate these general results, we consider the popular Gaussian Network Model (GNM) for protein conformational fluctuations. We analytically derive the exact PMF for the GNM as a function of the CG representation. In the case of the GNM, -TSW is a positive, configuration-independent term that depends upon the temperature, the complexity of the protein interaction network, and the details of the CG representation. This entropic term demonstrates similar behavior for seven model proteins and also suggests, in each case, that certain resolutions provide a more efficient description of protein fluctuations. These results may provide general insight into the role of resolution for determining the information content, thermodynamic properties, and transferability of CG models. Ultimately, they may lead to a rigorous and systematic framework for optimizing the representation of CG models.
18. The impact of resolution upon entropy and information in coarse-grained models
SciTech Connect
Foley, Thomas T.; Shell, M. Scott; Noid, W. G.
2015-12-28
By eliminating unnecessary degrees of freedom, coarse-grained (CG) models tremendously facilitate numerical calculations and theoretical analyses of complex phenomena. However, their success critically depends upon the representation of the system and the effective potential that governs the CG degrees of freedom. This work investigates the relationship between the CG representation and the many-body potential of mean force (PMF), W, which is the appropriate effective potential for a CG model that exactly preserves the structural and thermodynamic properties of a given high resolution model. In particular, we investigate the entropic component of the PMF and its dependence upon the CG resolution. This entropic component, S{sub W}, is a configuration-dependent relative entropy that determines the temperature dependence of W. As a direct consequence of eliminating high resolution details from the CG model, the coarsening process transfers configurational entropy and information from the configuration space into S{sub W}. In order to further investigate these general results, we consider the popular Gaussian Network Model (GNM) for protein conformational fluctuations. We analytically derive the exact PMF for the GNM as a function of the CG representation. In the case of the GNM, −TS{sub W} is a positive, configuration-independent term that depends upon the temperature, the complexity of the protein interaction network, and the details of the CG representation. This entropic term demonstrates similar behavior for seven model proteins and also suggests, in each case, that certain resolutions provide a more efficient description of protein fluctuations. These results may provide general insight into the role of resolution for determining the information content, thermodynamic properties, and transferability of CG models. Ultimately, they may lead to a rigorous and systematic framework for optimizing the representation of CG models.
19. Coarse-grained simulation of dynamin-mediated fission
Muller, Marcus; Zhang, Guojie; Fuhrmans, Marc
Fission is a process in which a region of a lipid bilayer is deformed and separated from its host membrane, so that an additional, topologically independent compartment surrounded by a continuous lipid bilayer is formed. It is a fundamental process in the compartmentalization of living organisms and carefully regulated by a number of membrane-shaping proteins. An important group within these is the dynamin family of proteins that are involved in the final severance of the hourglass-shaped neck, via which the growing compartment remains connected to the main volume until the completion of fission. We present computer simulations testing different hypotheses of how dynamin proteins facilitate fission by constriction and curvature. Our results on constraint-induced fission of cylindrical membrane tubes emphasize the importance of the local creation of positive curvature and reveal a complex picture of fission, in which the topological transformation can become arrested in an intermediate stage if the proteins constituting the fission machinery are not adaptive.
20. Preface: Special Topic on Coarse Graining of Macromolecules, Biopolymers, and Membranes.
PubMed
Holm, Christian; Gompper, Gerhard; Dill, Ken A
2015-12-28
This special issue highlights new developments in theory and coarse-graining in biological and synthetic macromolecules and membranes. Such approaches give unique insights into the principles and design of the structures, dynamics, and assembly processes of these complex fluids and soft materials, where the length and time scales are often prohibitively long for fully atomistic modeling. PMID:26723585
1. Toward Quantitative Coarse-Grained Models of Lipids with Fluids Density Functional Theory.
PubMed
Frink, Laura J Douglas; Frischknecht, Amalie L; Heroux, Michael A; Parks, Michael L; Salinger, Andrew G
2012-04-10
We describe methods to determine optimal coarse-grained models of lipid bilayers for use in fluids density functional theory (fluids-DFT) calculations. Both coarse-grained lipid architecture and optimal parametrizations of the models based on experimental measures are discussed in the context of dipalmitoylphosphatidylcholine (DPPC) lipid bilayers in water. The calculations are based on a combination of the modified-iSAFT theory for bonded systems and an accurate fundamental measures theory (FMT) for hard sphere reference fluids. We furthermore discuss a novel approach for pressure control in the fluids-DFT calculations that facilitates both partitioning studies and zero tension control for the bilayer studies. A detailed discussion of the numerical implementations for both solvers and pressure control capabilities are provided. We show that it is possible to develop a coarse-grained lipid bilayer model that is consistent with experimental properties (thickness and area per lipid) of DPPC provided that the coarse-graining is not too extreme. As a final test of the model, we find that the predicted area compressibility moduli and lateral pressure profiles of the optimized models are in reasonable agreement with prior results.
2. Coarse-grained molecular dynamics: Nonlinear finite elements and finite temperature
SciTech Connect
Rudd, R E; Broughton, J Q
2005-05-30
Coarse-grained molecular dynamics (CGMD) is a technique developed as a concurrent multiscale model that couples conventional molecular dynamics (MD) to a more coarse-grained description of the periphery. The coarse-grained regions are modeled on a mesh in a formulation that generalizes conventional finite element modeling (FEM) of continuum elasticity. CGMD is derived solely from the MD model, however, and has no continuum parameters. As a result, it provides a coupling that is smooth and provides control of errors that arise at the coupling between the atomistic and coarse-grained regions. In this article, we elaborate on the formulation of CGMD, describing in detail how CGMD is applied to anharmonic solids and finite temperature simulations. As tests of CGMD, we present in detail the calculation of the phonon spectra for solid argon and tantalum in 3D, demonstrating how CGMD provides a better description of the elastic waves than that provided by FEM. We also present elastic wave scattering calculations that show the elastic wave scattering is more benign in CGMD than FEM. We also discuss the dependence of scattering on the properties of the mesh. We introduce a rigid approximation to CGMD that eliminates internal relaxation, similar to the Quasicontinuum technique, and compare it to the full CGMD.
3. Insights into DNA-mediated interparticle interactions from a coarse-grained model
Ding, Yajun; Mittal, Jeetain
2014-11-01
DNA-functionalized particles have great potential for the design of complex self-assembled materials. The major hurdle in realizing crystal structures from DNA-functionalized particles is expected to be kinetic barriers that trap the system in metastable amorphous states. Therefore, it is vital to explore the molecular details of particle assembly processes in order to understand the underlying mechanisms. Molecular simulations based on coarse-grained models can provide a convenient route to explore these details. Most of the currently available coarse-grained models of DNA-functionalized particles ignore key chemical and structural details of DNA behavior. These models therefore are limited in scope for studying experimental phenomena. In this paper, we present a new coarse-grained model of DNA-functionalized particles which incorporates some of the desired features of DNA behavior. The coarse-grained DNA model used here provides explicit DNA representation (at the nucleotide level) and complementary interactions between Watson-Crick base pairs, which lead to the formation of single-stranded hairpin and double-stranded DNA. Aggregation between multiple complementary strands is also prevented in our model. We study interactions between two DNA-functionalized particles as a function of DNA grafting density, lengths of the hybridizing and non-hybridizing parts of DNA, and temperature. The calculated free energies as a function of pair distance between particles qualitatively resemble experimental measurements of DNA-mediated pair interactions.
4. Free-energy coarse-grained potential for C{sub 60}
SciTech Connect
Edmunds, D. M. Tangney, P.; Vvedensky, D. D.; Foulkes, W. M. C.
2015-10-28
We propose a new deformable free energy method for generating a free-energy coarse-graining potential for C{sub 60}. Potentials generated from this approach exhibit a strong temperature dependence and produce excellent agreement with benchmark fully atomistic molecular dynamics simulations. Parameter sets for analytical fits to this potential are provided at four different temperatures.
5. Path-space variational inference for non-equilibrium coarse-grained systems
Harmandaris, Vagelis; Kalligiannaki, Evangelia; Katsoulakis, Markos; Plecháč, Petr
2016-06-01
In this paper we discuss information-theoretic tools for obtaining optimized coarse-grained molecular models for both equilibrium and non-equilibrium molecular simulations. The latter are ubiquitous in physicochemical and biological applications, where they are typically associated with coupling mechanisms, multi-physics and/or boundary conditions. In general the non-equilibrium steady states are not known explicitly as they do not necessarily have a Gibbs structure. The presented approach can compare microscopic behavior of molecular systems to parametric and non-parametric coarse-grained models using the relative entropy between distributions on the path space and setting up a corresponding path-space variational inference problem. The methods can become entirely data-driven when the microscopic dynamics are replaced with corresponding correlated data in the form of time series. Furthermore, we present connections and generalizations of force matching methods in coarse-graining with path-space information methods. We demonstrate the enhanced transferability of information-based parameterizations to different observables, at a specific thermodynamic point, due to information inequalities. We discuss methodological connections between information-based coarse-graining of molecular systems and variational inference methods primarily developed in the machine learning community. However, we note that the work presented here addresses variational inference for correlated time series due to the focus on dynamics. The applicability of the proposed methods is demonstrated on high-dimensional stochastic processes given by overdamped and driven Langevin dynamics of interacting particles.
6. Coarse-grained cosmological perturbation theory: Stirring up the dust model
Uhlemann, Cora; Kopp, Michael
2015-04-01
We study the effect of coarse graining the dynamics of a pressureless self-gravitating fluid (coarse-grained dust) in the context of cosmological perturbation theory, in both the Eulerian and Lagrangian frameworks. We obtain recursion relations for the Eulerian perturbation kernels of the coarse-grained dust model by relating them to those of the standard pressureless fluid model. The effect of the coarse graining is illustrated by means of power and cross spectra for the density and velocity, which are computed up to one-loop order. In particular, the large-scale vorticity power spectrum that arises naturally from a mass-weighted velocity is derived from first principles. We find qualitatively good agreement for the magnitude, shape, and spectral index of the vorticity power spectrum with recent measurements from N -body simulations and results from the effective field theory of large-scale structure. To lay the ground for applications in the context of Lagrangian perturbation theory, we finally describe how the kernels obtained in Eulerian space can be mapped to Lagrangian ones.
7. Preface: Special Topic on Coarse Graining of Macromolecules, Biopolymers, and Membranes
SciTech Connect
Holm, Christian; Gompper, Gerhard; Dill, Ken A.
2015-12-28
This special issue highlights new developments in theory and coarse-graining in biological and synthetic macromolecules and membranes. Such approaches give unique insights into the principles and design of the structures, dynamics, and assembly processes of these complex fluids and soft materials, where the length and time scales are often prohibitively long for fully atomistic modeling.
8. Coarse-grained variables for particle-based models: diffusion maps and animal swarming simulations
Liu, Ping; Safford, Hannah R.; Couzin, Iain D.; Kevrekidis, Ioannis G.
2014-12-01
As microscopic (e.g. atomistic, stochastic, agent-based, particle-based) simulations become increasingly prevalent in the modeling of complex systems, so does the need to systematically coarse-grain the information they provide. Before even starting to formulate relevant coarse-grained equations, we need to determine the right macroscopic observables—the right variables in terms of which emergent behavior will be described. This paper illustrates the use of data mining (and, in particular, diffusion maps, a nonlinear manifold learning technique) in coarse-graining the dynamics of a particle-based model of animal swarming. Our computational data-driven coarse-graining approach extracts two coarse (collective) variables from the detailed particle-based simulations, and helps formulate a low-dimensional stochastic differential equation in terms of these two collective variables; this allows the efficient quantification of the interplay of "informed" and "naive" individuals in the collective swarm dynamics. We also present a brief exploration of swarm breakup and use data-mining in an attempt to identify useful predictors for it. In our discussion of the scope and limitations of the approach we focus on the key step of selecting an informative metric, allowing us to usefully compare different particle swarm configurations.
9. Preface: Special Topic on Coarse Graining of Macromolecules, Biopolymers, and Membranes.
PubMed
Holm, Christian; Gompper, Gerhard; Dill, Ken A
2015-12-28
This special issue highlights new developments in theory and coarse-graining in biological and synthetic macromolecules and membranes. Such approaches give unique insights into the principles and design of the structures, dynamics, and assembly processes of these complex fluids and soft materials, where the length and time scales are often prohibitively long for fully atomistic modeling.
10. Association, intrinsic shape, and molecular recognition: Elucidating DNA biophysics through coarse-grained simulation
Freeman, Gordon Samuel
DNA is of central importance in biology as it is responsible for carrying, copying, and translating the genetic code into the building blocks that comprise life. In order to accomplish these tasks, the DNA molecule must be versatile and robust. Indeed, the underlying molecular interactions that allow DNA to execute these tasks are complex and their origins are only beginning to be understood. While experiments are able to elucidate many key biophysical phenomena, there remain many unanswered questions. Molecular simulation is able to shed light on phenomena at the molecular scale and provide information that is missing from experimental views of DNA behavior. In this dissertation I use state-of-the-art coarse-grained DNA models to address two key problems. In the first, metadynamics calculations are employed to uncover the free energy surface of two complimentary DNA strands. This free energy surface takes on the appearance of a hybridization funnel and reveals candidates for intermediate states in the hybridization of short DNA oligomers. Such short oligomers are important building blocks for DNA-driven self-assembly and the mechanism of hybridization in this regime is not well understood. The second problem is that of nucleosome formation. Nucleosomes are the fundamental subunit of genome compaction in the nucleus of a cell. As such, nucleosomes are a key epigenetic factor and affect gene expression and the ability of DNA-binding proteins to locate and bind to the appropriate position in the genome. However, the factors that drive nucleosome positioning are not well understood. While DNA sequence is known to affect nucleosome formation, the mechanism by which it does so has not been established and a number of hypotheses explaining this sequence-dependence exist in the literature. I demonstrate that DNA shape dominates this process with contributions arising from both intrinsic DNA curvature as well as DNA-protein interactions driven by sequence
11. Nucleotide-induced conformational dynamics in ABC transporters from structure-based coarse grained modelling.
Flechsig, Holger
2016-02-01
ATP-binding cassette (ABC) transporters are integral membrane proteins which mediate the exchange of diverse substrates across membranes powered by ATP molecules. Our understanding of their activity is still hampered since the conformational dynamics underlying the operation of such proteins cannot yet be resolved in detailed molecular dynamics studies. Here a coarse grained model which allows to mimic binding of nucleotides and follow subsequent conformational motions of full-length transporter structures in computer simulations is proposed and implemented. To justify its explanatory quality, the model is first applied to the maltose transporter system for which multiple conformations are known and we find that the model predictions agree remarkably well with the experimental data. For the MalK subunit the switching from open to the closed dimer configuration upon ATP binding is reproduced and, moreover, for the full-length maltose transporter, progression from inward-facing to the outward-facing state is correctly obtained. For the heme transporter HmuUV, for which only the free structure could yet be determined, the model was then applied to predict nucleotide-induced conformational motions. Upon binding of ATP-mimicking ligands the structure changed from a conformation in which the nucleotide-binding domains formed an open shape, to a conformation in which they were found in tight contact, while, at the same time, a pronounced rotation of the transmembrane domains was observed. This finding is supported by normal mode analysis, and, comparison with structural data of the homologous vitamin B12 transporter BtuCD suggests that the observed rotation mechanism may contribute a common functional aspect for this class of ABC transporters. Although in HmuuV noticeable rearrangement of essential transmembrane helices was detected, there are no indications from our simulations that ATP binding alone may facilitate propagation of substrate molecules in this transporter
12. Vapor Pressure of Aqueous Solutions of Electrolytes Reproduced with Coarse-Grained Models without Electrostatics.
PubMed
Perez Sirkin, Yamila A; Factorovich, Matías H; Molinero, Valeria; Scherlis, Damian A
2016-06-14
The vapor pressure of water is a key property in a large class of applications from the design of membranes for fuel cells and separations to the prediction of the mixing state of atmospheric aerosols. Molecular simulations have been used to compute vapor pressures, and a few studies on liquid mixtures and solutions have been reported on the basis of the Gibbs Ensemble Monte Carlo method in combination with atomistic force fields. These simulations are costly, making them impractical for the prediction of the vapor pressure of complex materials. The goal of the present work is twofold: (1) to demonstrate the use of the grand canonical screening approach ( Factorovich , M. H. J. Chem. Phys. 2014 , 140 , 064111 ) to compute the vapor pressure of solutions and to extend the methodology for the treatment of systems without a liquid-vapor interface and (2) to investigate the ability of computationally efficient high-resolution coarse-grained models based on the mW monatomic water potential and ions described exclusively with short-range interactions to reproduce the relative vapor pressure of aqueous solutions. We find that coarse-grained models of LiCl and NaCl solutions faithfully reproduce the experimental relative pressures up to high salt concentrations, despite the inability of these models to predict cohesive energies of the solutions or the salts. A thermodynamic analysis reveals that the coarse-grained models achieve the experimental activity coefficients of water in solution through a compensation of severely underestimated hydration and vaporization free energies of the salts. Our results suggest that coarse-grained models developed to replicate the hydration structure and the effective ion-ion attraction in solution may lead to this compensation. Moreover, they suggest an avenue for the design of coarse-grained models that accurately reproduce the activity coefficients of solutions.
13. Vapor Pressure of Aqueous Solutions of Electrolytes Reproduced with Coarse-Grained Models without Electrostatics.
PubMed
Perez Sirkin, Yamila A; Factorovich, Matías H; Molinero, Valeria; Scherlis, Damian A
2016-06-14
The vapor pressure of water is a key property in a large class of applications from the design of membranes for fuel cells and separations to the prediction of the mixing state of atmospheric aerosols. Molecular simulations have been used to compute vapor pressures, and a few studies on liquid mixtures and solutions have been reported on the basis of the Gibbs Ensemble Monte Carlo method in combination with atomistic force fields. These simulations are costly, making them impractical for the prediction of the vapor pressure of complex materials. The goal of the present work is twofold: (1) to demonstrate the use of the grand canonical screening approach ( Factorovich , M. H. J. Chem. Phys. 2014 , 140 , 064111 ) to compute the vapor pressure of solutions and to extend the methodology for the treatment of systems without a liquid-vapor interface and (2) to investigate the ability of computationally efficient high-resolution coarse-grained models based on the mW monatomic water potential and ions described exclusively with short-range interactions to reproduce the relative vapor pressure of aqueous solutions. We find that coarse-grained models of LiCl and NaCl solutions faithfully reproduce the experimental relative pressures up to high salt concentrations, despite the inability of these models to predict cohesive energies of the solutions or the salts. A thermodynamic analysis reveals that the coarse-grained models achieve the experimental activity coefficients of water in solution through a compensation of severely underestimated hydration and vaporization free energies of the salts. Our results suggest that coarse-grained models developed to replicate the hydration structure and the effective ion-ion attraction in solution may lead to this compensation. Moreover, they suggest an avenue for the design of coarse-grained models that accurately reproduce the activity coefficients of solutions. PMID:27196963
14. Modeling Structural Dynamics of Biomolecular Complexes by Coarse-Grained Molecular Simulations.
PubMed
Takada, Shoji; Kanada, Ryo; Tan, Cheng; Terakawa, Tsuyoshi; Li, Wenfei; Kenzaki, Hiroo
2015-12-15
Due to hierarchic nature of biomolecular systems, their computational modeling calls for multiscale approaches, in which coarse-grained (CG) simulations are used to address long-time dynamics of large systems. Here, we review recent developments and applications of CG modeling methods, focusing on our methods primarily for proteins, DNA, and their complexes. These methods have been implemented in the CG biomolecular simulator, CafeMol. Our CG model has resolution such that ∼10 non-hydrogen atoms are grouped into one CG particle on average. For proteins, each amino acid is represented by one CG particle. For DNA, one nucleotide is simplified by three CG particles, representing sugar, phosphate, and base. The protein modeling is based on the idea that proteins have a globally funnel-like energy landscape, which is encoded in the structure-based potential energy function. We first describe two representative minimal models of proteins, called the elastic network model and the classic Go̅ model. We then present a more elaborate protein model, which extends the minimal model to incorporate sequence and context dependent local flexibility and nonlocal contacts. For DNA, we describe a model developed by de Pablo's group that was tuned to well reproduce sequence-dependent structural and thermodynamic experimental data for single- and double-stranded DNAs. Protein-DNA interactions are modeled either by the structure-based term for specific cases or by electrostatic and excluded volume terms for nonspecific cases. We also discuss the time scale mapping in CG molecular dynamics simulations. While the apparent single time step of our CGMD is about 10 times larger than that in the fully atomistic molecular dynamics for small-scale dynamics, large-scale motions can be further accelerated by two-orders of magnitude with the use of CG model and a low friction constant in Langevin dynamics. Next, we present four examples of applications. First, the classic Go̅ model was used to
15. Probing the folded state and mechanical unfolding pathways of T4 lysozyme using all-atom and coarse-grained molecular simulation
Zheng, Wenjun; Glenn, Paul
2015-01-01
The Bacteriophage T4 Lysozyme (T4L) is a prototype modular protein comprised of an N-terminal and a C-domain domain, which was extensively studied to understand the folding/unfolding mechanism of modular proteins. To offer detailed structural and dynamic insights to the folded-state stability and the mechanical unfolding behaviors of T4L, we have performed extensive equilibrium and steered molecular dynamics simulations of both the wild-type (WT) and a circular permutation (CP) variant of T4L using all-atom and coarse-grained force fields. Our all-atom and coarse-grained simulations of the folded state have consistently found greater stability of the C-domain than the N-domain in isolation, which is in agreement with past thermostatic studies of T4L. While the all-atom simulation cannot fully explain the mechanical unfolding behaviors of the WT and the CP variant observed in an optical tweezers study, the coarse-grained simulations based on the Go model or a modified elastic network model (mENM) are in qualitative agreement with the experimental finding of greater unfolding cooperativity in the WT than the CP variant. Interestingly, the two coarse-grained models predict different structural mechanisms for the observed change in cooperativity between the WT and the CP variant—while the Go model predicts minor modification of the unfolding pathways by circular permutation (i.e., preserving the general order that the N-domain unfolds before the C-domain), the mENM predicts a dramatic change in unfolding pathways (e.g., different order of N/C-domain unfolding in the WT and the CP variant). Based on our simulations, we have analyzed the limitations of and the key differences between these models and offered testable predictions for future experiments to resolve the structural mechanism for cooperative folding/unfolding of T4L.
16. Probing the folded state and mechanical unfolding pathways of T4 lysozyme using all-atom and coarse-grained molecular simulation
SciTech Connect
Zheng, Wenjun Glenn, Paul
2015-01-21
The Bacteriophage T4 Lysozyme (T4L) is a prototype modular protein comprised of an N-terminal and a C-domain domain, which was extensively studied to understand the folding/unfolding mechanism of modular proteins. To offer detailed structural and dynamic insights to the folded-state stability and the mechanical unfolding behaviors of T4L, we have performed extensive equilibrium and steered molecular dynamics simulations of both the wild-type (WT) and a circular permutation (CP) variant of T4L using all-atom and coarse-grained force fields. Our all-atom and coarse-grained simulations of the folded state have consistently found greater stability of the C-domain than the N-domain in isolation, which is in agreement with past thermostatic studies of T4L. While the all-atom simulation cannot fully explain the mechanical unfolding behaviors of the WT and the CP variant observed in an optical tweezers study, the coarse-grained simulations based on the Go model or a modified elastic network model (mENM) are in qualitative agreement with the experimental finding of greater unfolding cooperativity in the WT than the CP variant. Interestingly, the two coarse-grained models predict different structural mechanisms for the observed change in cooperativity between the WT and the CP variant—while the Go model predicts minor modification of the unfolding pathways by circular permutation (i.e., preserving the general order that the N-domain unfolds before the C-domain), the mENM predicts a dramatic change in unfolding pathways (e.g., different order of N/C-domain unfolding in the WT and the CP variant). Based on our simulations, we have analyzed the limitations of and the key differences between these models and offered testable predictions for future experiments to resolve the structural mechanism for cooperative folding/unfolding of T4L.
17. An adaptive coarse graining method for signal transduction in three dimensions
PubMed Central
Archuleta, Michelle N.; McDermott, Jason E.; Edwards, Jeremy S.; Resat, Haluk
2013-01-01
The spatio-temporal landscape of the plasma membrane regulates activation and signal transduction of membrane bound receptors by restricting their two-dimensional mobility and by inducing receptor clustering. This regulation also extends to complex formation between receptors and adaptor proteins, which are the intermediate signaling molecules involved in cellular signaling that relay the received cues from cell surface to cytoplasm and eventually to the nucleus. Although their investigation poses challenging technical difficulties, there is a crucial need to understand the impact of the receptor diffusivity, clustering, and spatial heterogeneity, and of receptor-adaptor protein complex formation on the cellular signal transduction patterns. Building upon our earlier studies, we have developed an adaptive coarse-grained Monte Carlo method that can be used to investigate the role of diffusion, clustering and membrane corralling on receptor association and receptor-adaptor protein complex formation dynamics in three dimensions. The new Monte Carlo lattice based approach allowed us to introduce spatial resolution on the 2-D plasma membrane and to model the cytoplasm in three-dimensions. Being a multi-resolution approach, our new method makes it possible to represent various parts of the cellular system at different levels of detail and enabled us to utilize the locally homogeneous assumption when justified (e.g., cytoplasmic region away from the cell membrane) and avoid its use when high spatial resolution is needed (e.g., cell membrane and cytoplasmic region near the membrane) while keeping the required computational complexity manageable. Our results have shown that diffusion has a significant impact on receptor-receptor dimerization and receptor-adaptor protein complex formation kinetics. We have observed an “adaptor protein hopping” mechanism where the receptor binding proteins may hop between receptors to form short-lived transient complexes. This increased
18. A Coarse-Grained Model for Polyglutamine Aggregation Modulated by Amphipathic Flanking Sequences
PubMed Central
Ruff, Kiersten M.; Khan, Siddique J.; Pappu, Rohit V.
2014-01-01
The aggregation of proteins with expanded polyglutamine (polyQ) tracts is directly relevant to the formation of neuronal intranuclear inclusions in Huntington’s disease. In vitro studies have uncovered the effects of flanking sequences as modulators of the driving forces and mechanisms of polyQ aggregation in sequence segments associated with HD. Specifically, a seventeen-residue amphipathic stretch (N17) that is directly N-terminal to the polyQ tract in huntingtin decreases the overall solubility, destabilizes nonfibrillar aggregates, and accelerates fibril formation. Published results from atomistic simulations showed that the N17 module reduces the frequency of intermolecular association. Our reanalysis of these simulation results demonstrates that the N17 module also reduces interchain entanglements between polyQ domains. These two effects, which are observed on the smallest lengthscales, are incorporated into phenomenological pair potentials and used in coarse-grained Brownian dynamics simulations to investigate their impact on large-scale aggregation. We analyze the results from Brownian dynamics simulations using the framework of diffusion-limited cluster aggregation. When entanglements prevail, which is true in the absence of N17, small spherical clusters and large linear aggregates form on distinct timescales, in accord with in vitro experiments. Conversely, when entanglements are quenched and a barrier to intermolecular associations is introduced, both of which are attributable to N17, the timescales for forming small species and large linear aggregates become similar. Therefore, the combination of a reduction of interchain entanglements through homopolymeric polyQ and barriers to intermolecular associations appears to be sufficient for providing a minimalist phenomenological rationalization of in vitro observations regarding the effects of N17 on polyQ aggregation. PMID:25185558
19. A test of systematic coarse-graining of molecular dynamics simulations: Transport properties
Fu, Chia-Chun; Kulkarni, Pandurang M.; Shell, M. Scott; Leal, L. Gary
2013-09-01
To what extent can a "bottom-up" mesoscale fluid model developed through systematic coarse-graining techniques recover the physical properties of a molecular scale system? In a previous paper [C.-C. Fu, P. M. Kulkarni, M. S. Shell, and L. G. Leal, J. Chem. Phys. 137, 164106 (2012)], 10.1063/1.4759463, we addressed this question for thermodynamic properties through the development of coarse-grained (CG) fluid models using modified iterative Boltzmann inversion methods that reproduce correct pair structure and pressure. In the present work we focus on the dynamic behavior. Unlike the radial distribution function and the pressure, dynamical properties such as the self-diffusion coefficient and viscosity in a CG model cannot be matched during coarse-graining by modifying the pair interaction. Instead, removed degrees of freedom require a modification of the equations of motion to simulate their implicit effects on dynamics. A simple but approximate approach is to introduce a friction coefficient, γ, and random forces for the remaining degrees of freedom, in which case γ becomes an additional parameter in the coarse-grained model that can be tuned. We consider the non-Galilean-invariant Langevin and the Galilean-invariant dissipative particle dynamics (DPD) thermostats with CG systems in which we can systematically tune the fraction ϕ of removed degrees of freedom. Between these two choices, only DPD allows both the viscosity and diffusivity to match a reference Lennard-Jones liquid with a single value of γ for each degree of coarse-graining ϕ. This friction constant is robust to the pressure correction imposed on the effective CG potential, increases approximately linearly with ϕ, and also depends on the interaction cutoff length, rcut, of the pair interaction potential. Importantly, we show that the diffusion constant and viscosity are constrained by a simple scaling law that leads to a specific choice of DPD friction coefficient for a given degree of coarse-graining
20. Heterogeneous lamella structure unites ultrafine-grain strength with coarse-grain ductility.
PubMed
Wu, Xiaolei; Yang, Muxin; Yuan, Fuping; Wu, Guilin; Wei, Yujie; Huang, Xiaoxu; Zhu, Yuntian
2015-11-24
Grain refinement can make conventional metals several times stronger, but this comes at dramatic loss of ductility. Here we report a heterogeneous lamella structure in Ti produced by asymmetric rolling and partial recrystallization that can produce an unprecedented property combination: as strong as ultrafine-grained metal and at the same time as ductile as conventional coarse-grained metal. It also has higher strain hardening than coarse-grained Ti, which was hitherto believed impossible. The heterogeneous lamella structure is characterized with soft micrograined lamellae embedded in hard ultrafine-grained lamella matrix. The unusual high strength is obtained with the assistance of high back stress developed from heterogeneous yielding, whereas the high ductility is attributed to back-stress hardening and dislocation hardening. The process discovered here is amenable to large-scale industrial production at low cost, and might be applicable to other metal systems. PMID:26554017
1. Stochastic thermodynamics of fluctuating density fields: Non-equilibrium free energy differences under coarse-graining
SciTech Connect
Leonard, T.; Lander, B.; Seifert, U.; Speck, T.
2013-11-28
We discuss the stochastic thermodynamics of systems that are described by a time-dependent density field, for example, simple liquids and colloidal suspensions. For a time-dependent change of external parameters, we show that the Jarzynski relation connecting work with the change of free energy holds if the time evolution of the density follows the Kawasaki-Dean equation. Specifically, we study the work distributions for the compression and expansion of a two-dimensional colloidal model suspension implementing a practical coarse-graining scheme of the microscopic particle positions. We demonstrate that even if coarse-grained dynamics and density functional do not match, the fluctuation relations for the work still hold albeit for a different, apparent, change of free energy.
2. Simulating Cellulose Structure, Properties, Thermodynamics, Synthesis, and Deconstruction with Atomistic and Coarse-Grain Models
SciTech Connect
Crowley, M. F.; Matthews, J.; Beckham, G.; Bomble, Y.; Hynninen, A. P.; Ciesielski, P. F.
2012-01-01
Cellulose is still a mysterious polymer in many ways: structure of microfibrils, thermodynamics of synthesis and degradation, and interactions with other plant cell wall components. Our aim is to uncover the details and mechanisms of cellulose digestion and synthesis. We report the details of the structure of cellulose 1-beta under several temperature conditions and report here the results of these studies and connections to experimental measurements and the measurement in-silico the free energy of decrystallization of several morphologies of cellulose. In spatially large modeling, we show the most recent work of mapping atomistic and coarse-grain models into tomographic images of cellulose and extreme coarse-grain modeling of interactions of large cellulase complexes with microfibrils. We discuss the difficulties of modeling cellulose and suggest future work both experimental and theoretical to increase our understanding of cellulose and our ability to use it as a raw material for fuels and materials.
3. Systematic coarse-grained modeling of complexation between small interfering RNA and polycations
SciTech Connect
Wei, Zonghui; Luijten, Erik
2015-12-28
All-atom molecular dynamics simulations can provide insight into the properties of polymeric gene-delivery carriers by elucidating their interactions and detailed binding patterns with nucleic acids. However, to explore nanoparticle formation through complexation of these polymers and nucleic acids and study their behavior at experimentally relevant time and length scales, a reliable coarse-grained model is needed. Here, we systematically develop such a model for the complexation of small interfering RNA (siRNA) and grafted polyethyleneimine copolymers, a promising candidate for siRNA delivery. We compare the predictions of this model with all-atom simulations and demonstrate that it is capable of reproducing detailed binding patterns, charge characteristics, and water release kinetics. Since the coarse-grained model accelerates the simulations by one to two orders of magnitude, it will make it possible to quantitatively investigate nanoparticle formation involving multiple siRNA molecules and cationic copolymers.
4. Short-range, overpressure-driven methane migration in coarse-grained gas hydrate reservoirs
Nole, Michael; Daigle, Hugh; Cook, Ann E.; Malinverno, Alberto
2016-09-01
Two methane migration mechanisms have been proposed for coarse-grained gas hydrate reservoirs: short-range diffusive gas migration and long-range advective fluid transport from depth. Herein, we demonstrate that short-range fluid flow due to overpressure in marine sediments is a significant additional methane transport mechanism that allows hydrate to precipitate in large quantities in thick, coarse-grained hydrate reservoirs. Two-dimensional simulations demonstrate that this migration mechanism, short-range advective transport, can supply significant amounts of dissolved gas and is unencumbered by limitations of the other two end-member mechanisms. Short-range advective migration can increase the amount of methane delivered to sands as compared to the slow process of diffusion, yet it is not necessarily limited by effective porosity reduction as is typical of updip advection from a deep source.
5. Heterogeneous lamella structure unites ultrafine-grain strength with coarse-grain ductility
PubMed Central
Wu, Xiaolei; Yang, Muxin; Yuan, Fuping; Wu, Guilin; Wei, Yujie; Huang, Xiaoxu; Zhu, Yuntian
2015-01-01
Grain refinement can make conventional metals several times stronger, but this comes at dramatic loss of ductility. Here we report a heterogeneous lamella structure in Ti produced by asymmetric rolling and partial recrystallization that can produce an unprecedented property combination: as strong as ultrafine-grained metal and at the same time as ductile as conventional coarse-grained metal. It also has higher strain hardening than coarse-grained Ti, which was hitherto believed impossible. The heterogeneous lamella structure is characterized with soft micrograined lamellae embedded in hard ultrafine-grained lamella matrix. The unusual high strength is obtained with the assistance of high back stress developed from heterogeneous yielding, whereas the high ductility is attributed to back-stress hardening and dislocation hardening. The process discovered here is amenable to large-scale industrial production at low cost, and might be applicable to other metal systems. PMID:26554017
6. Consistent and transferable coarse-grained model for semidilute polymer solutions in good solvent.
PubMed
D'Adamo, Giuseppe; Pelissetto, Andrea; Pierleoni, Carlo
2012-07-14
We present a coarse-grained model for linear polymers with a tunable number of effective atoms (blobs) per chain interacting by intra- and intermolecular potentials obtained at zero density. We show how this model is able to accurately reproduce the universal properties of the underlying solution of athermal linear chains at various levels of coarse-graining and in a range of chain densities which can be widened by increasing the spatial resolution of the multiblob representation, i.e., the number of blobs per chain. The present model is unique in its ability to quantitatively predict thermodynamic and large scale structural properties of polymer solutions deep in the semidilute regime with a very limited computational effort, overcoming most of the problems related to the simulations of semidilute polymer solutions in good solvent conditions.
7. Tensor network algorithm by coarse-graining tensor renormalization on finite periodic lattices
Zhao, Hui-Hai; Xie, Zhi-Yuan; Xiang, Tao; Imada, Masatoshi
2016-03-01
We develop coarse-graining tensor renormalization group algorithms to compute physical properties of two-dimensional lattice models on finite periodic lattices. Two different coarse-graining strategies, one based on the tensor renormalization group and the other based on the higher-order tensor renormalization group, are introduced. In order to optimize the tensor network model globally, a sweeping scheme is proposed to account for the renormalization effect from the environment tensors under the framework of second renormalization group. We demonstrate the algorithms by the classical Ising model on the square lattice and the Kitaev model on the honeycomb lattice, and show that the finite-size algorithms achieve substantially more accurate results than the corresponding infinite-size ones.
8. Premelting, fluctuations, and coarse-graining of water-ice interfaces
SciTech Connect
Limmer, David T.; Chandler, David
2014-11-14
Using statistical field theory supplemented with molecular dynamics simulations, we consider premelting on the surface of ice as a generic consequence of broken hydrogen bonds at the boundary between the condensed and gaseous phases. A procedure for coarse-graining molecular configurations onto a continuous scalar order parameter field is discussed, which provides a convenient representation of the interface between locally crystal-like and locally liquid-like regions. A number of interfacial properties are straightforwardly evaluated using this procedure such as the average premelting thickness and surface tension. The temperature and system size dependence of the premelting layer thickness calculated in this way confirms the characteristic logarithmic growth expected for the scalar field theory that the system is mapped onto through coarse-graining, though remains finite due to long-ranged interactions. Finally, from explicit simulations the existence of a premelting layer is shown to be insensitive to bulk lattice geometry, exposed crystal face, and curvature.
9. Short-range, overpressure-driven methane migration in coarse-grained gas hydrate reservoirs
DOE PAGESBeta
Nole, Michael; Daigle, Hugh; Cook, Ann E.; Malinverno, Alberto
2016-08-31
Two methane migration mechanisms have been proposed for coarse-grained gas hydrate reservoirs: short-range diffusive gas migration and long-range advective fluid transport from depth. Herein we demonstrate that short-range fluid flow due to overpressure in marine sediments is a significant additional methane transport mechanism that allows hydrate to precipitate in large quantities in thick, coarse-grained hydrate reservoirs. Two-dimensional simulations demonstrate that this migration mechanism, short-range advective transport, can supply significant amounts of dissolved gas and is unencumbered by limitations of the other two end-member mechanisms. Here, short-range advective migration can increase the amount of methane delivered to sands as compared tomore » the slow process of diffusion, yet it is not necessarily limited by effective porosity reduction as is typical of updip advection from a deep source.« less
10. N-Body interactions in soft-sphere coarse-grained models of star polymers.
PubMed
Pelissetto, Andrea
2012-02-01
We consider the coarse-grained approach in which star polymers are mapped onto atoms located at the centers of the stars interacting by means of ultrasoft potentials. We generalize the Witten-Pincus formula to all n-body potentials: in the good-solvent regime all potentials show an ultrasoft logarithmic divergence when the relative distance of all n stars goes to zero, with coefficients that can be related to the partition-function exponents γ(f). PMID:22463232
11. Improved Coarse-Grained Modeling of Cholesterol-Containing Lipid Bilayers
PubMed Central
2015-01-01
Cholesterol trafficking, which is an essential function in mammalian cells, is intimately connected to molecular-scale interactions through cholesterol modulation of membrane structure and dynamics and interaction with membrane receptors. Since these effects of cholesterol occur on micro- to millisecond time scales, it is essential to develop accurate coarse-grained simulation models that can reach these time scales. Cholesterol has been shown experimentally to thicken the membrane and increase phospholipid tail order between 0 and 40% cholesterol, above which these effects plateau or slightly decrease. Here, we showed that the published MARTINI coarse-grained force-field for phospholipid (POPC) and cholesterol fails to capture these effects. Using reference atomistic simulations, we systematically modified POPC and cholesterol bonded parameters in MARTINI to improve its performance. We showed that the corrections to pseudobond angles between glycerol and the lipid tails and around the oleoyl double bond particle (the “angle-corrected model”) slightly improves the agreement of MARTINI with experimentally measured thermal, elastic, and dynamic properties of POPC membranes. The angle-corrected model improves prediction of the thickening and ordering effects up to 40% cholesterol but overestimates these effects at higher cholesterol concentration. In accordance with prior work that showed the cholesterol rough face methyl groups are important for limiting cholesterol self-association, we revised the coarse-grained representation of these methyl groups to better match cholesterol-cholesterol radial distribution functions from atomistic simulations. In addition, by using a finer-grained representation of the branched cholesterol tail than MARTINI, we improved predictions of lipid tail order and bilayer thickness across a wide range of concentrations. Finally, transferability testing shows that a model incorporating our revised parameters into DOPC outperforms other
12. Conservative and dissipative force field for simulation of coarse-grained alkane molecules: A bottom-up approach
SciTech Connect
Trément, Sébastien; Rousseau, Bernard; Schnell, Benoît; Petitjean, Laurent; Couty, Marc
2014-04-07
We apply operational procedures available in the literature to the construction of coarse-grained conservative and friction forces for use in dissipative particle dynamics (DPD) simulations. The full procedure rely on a bottom-up approach: large molecular dynamics trajectories of n-pentane and n-decane modeled with an anisotropic united atom model serve as input for the force field generation. As a consequence, the coarse-grained model is expected to reproduce at least semi-quantitatively structural and dynamical properties of the underlying atomistic model. Two different coarse-graining levels are studied, corresponding to five and ten carbon atoms per DPD bead. The influence of the coarse-graining level on the generated force fields contributions, namely, the conservative and the friction part, is discussed. It is shown that the coarse-grained model of n-pentane correctly reproduces self-diffusion and viscosity coefficients of real n-pentane, while the fully coarse-grained model for n-decane at ambient temperature over-predicts diffusion by a factor of 2. However, when the n-pentane coarse-grained model is used as a building block for larger molecule (e.g., n-decane as a two blobs model), a much better agreement with experimental data is obtained, suggesting that the force field constructed is transferable to large macro-molecular systems.
13. Conservative and dissipative force field for simulation of coarse-grained alkane molecules: A bottom-up approach
Trément, Sébastien; Schnell, Benoît.; Petitjean, Laurent; Couty, Marc; Rousseau, Bernard
2014-04-01
We apply operational procedures available in the literature to the construction of coarse-grained conservative and friction forces for use in dissipative particle dynamics (DPD) simulations. The full procedure rely on a bottom-up approach: large molecular dynamics trajectories of n-pentane and n-decane modeled with an anisotropic united atom model serve as input for the force field generation. As a consequence, the coarse-grained model is expected to reproduce at least semi-quantitatively structural and dynamical properties of the underlying atomistic model. Two different coarse-graining levels are studied, corresponding to five and ten carbon atoms per DPD bead. The influence of the coarse-graining level on the generated force fields contributions, namely, the conservative and the friction part, is discussed. It is shown that the coarse-grained model of n-pentane correctly reproduces self-diffusion and viscosity coefficients of real n-pentane, while the fully coarse-grained model for n-decane at ambient temperature over-predicts diffusion by a factor of 2. However, when the n-pentane coarse-grained model is used as a building block for larger molecule (e.g., n-decane as a two blobs model), a much better agreement with experimental data is obtained, suggesting that the force field constructed is transferable to large macro-molecular systems.
14. Model reduction for agent-based social simulation: coarse-graining a civil violence model.
PubMed
Zou, Yu; Fonoberov, Vladimir A; Fonoberova, Maria; Mezic, Igor; Kevrekidis, Ioannis G
2012-06-01
Agent-based modeling (ABM) constitutes a powerful computational tool for the exploration of phenomena involving emergent dynamic behavior in the social sciences. This paper demonstrates a computer-assisted approach that bridges the significant gap between the single-agent microscopic level and the macroscopic (coarse-grained population) level, where fundamental questions must be rationally answered and policies guiding the emergent dynamics devised. Our approach will be illustrated through an agent-based model of civil violence. This spatiotemporally varying ABM incorporates interactions between a heterogeneous population of citizens [active (insurgent), inactive, or jailed] and a population of police officers. Detailed simulations exhibit an equilibrium punctuated by periods of social upheavals. We show how to effectively reduce the agent-based dynamics to a stochastic model with only two coarse-grained degrees of freedom: the number of jailed citizens and the number of active ones. The coarse-grained model captures the ABM dynamics while drastically reducing the computation time (by a factor of approximately 20).
15. Multiscale Coarse-graining and Structural Correlations: Connections to Liquid State Theory
PubMed Central
Noid, W. G.; Chu, Jhih-Wei; Ayton, Gary S.; Voth, Gregory A.
2008-01-01
A statistical mechanical framework elucidates the significance of structural correlations between coarse-grained (CG) sites in the multiscale coarse-graining (MS-CG) method [S. Izvekov and G.A. Voth. J. Phys. Chem. B 109 2469 (2005), J. Chem. Phys. 123 134105 (2005)]. If no approximations are made, the MS-CG method yields a many-body multi-dimensional potential of mean force describing the interactions between CG sites. However, numerical applications of the MS-CG method typically employ a set of pair potentials to describe non-bonded interactions. The analogy between coarse-graining and the inverse problem of liquid state theory clarifies the general significance of three-particle correlations for the development of such CG pair potentials. It is demonstrated that the MS-CG methodology incorporates critical three-body correlation effects and that, for isotropic homogeneous systems evolving under a central pair potential, the MS-CG equations are a discretized representation of the well-known Yvon-Born-Green equation. Numerical calculations validate the theory and illustrate the role of these structural correlations in the MS-CG method. PMID:17394308
16. Theoretical reconstruction of realistic dynamics of highly coarse-grained cis-1,4-polybutadiene melts
Lyubimov, I. Y.; Guenza, M. G.
2013-03-01
The theory to reconstruct the atomistic-level chain diffusion from the accelerated dynamics that is measured in mesoscale simulations of the coarse-grained system, is applied here to the dynamics of cis-1,4-polybutadiene melts where each chain is described as a soft interacting colloidal particle. The rescaling formalism accounts for the corrections in the dynamics due to the change in entropy and the change in friction that are a consequence of the coarse-graining procedure. By including these two corrections the dynamics is rescaled to reproduce the realistic dynamics of the system described at the atomistic level. The rescaled diffusion coefficient obtained from mesoscale simulations of coarse-grained cis-1,4-polybutadiene melts shows good agreement with data from united atom simulations performed by Tsolou et al. [Macromolecules 38, 1478 (2005)], 10.1021/ma0491210. The derived monomer friction coefficient is used as an input to the theory for cooperative dynamics that describes the internal dynamics of a polymer moving in a transient regions of slow cooperative motion in a liquid of macromolecules. Theoretically predicted time correlation functions show good agreement with simulations in the whole range of length and time scales in which data are available.
17. Multiscale simulation of thin-film lubrication: Free-energy-corrected coarse graining
Wu, Z.-B.; Zeng, X. C.
2014-09-01
The quasicontinuum method was previously extended to the nonzero temperature conditions by implementing a free-energy correction on non-nodal atoms in coarse-grained solid systems to avoid the dynamical constraint, [Diestler, Wu, and Zeng, J. Chem. Phys. 121, 9279 (2004), 10.1063/1.1806811]. In this paper, we combine the extended quasicontinuum method and an atomistic simulation to treat the monolayer film lubrication with elastic (nonrigid) substrates. It is shown that the multiscale method with the coarse-graining local elements in the merging regions between the atomistic and continuous descriptions of the substrates can reasonably predict the shear stress profile, the mean separation curve, and the transverse stress profile in the fully atomistic simulation for the tribological system. Moreover, when the nonlocal elements are placed in the merging regions, the inhomogeneous solid atoms in the near regions covered by the cut-off circles of the nonlocal elements replace the homogeneous ones at the equilibrium configuration for the free-energy correction on the non-nodal atoms. The treatment can cause an unphysical sliding between the near and far regions of the upper substrate. It is shown that if the free-energy correction on the non-nodal atoms in the coarse-grained merging regions is removed, the multiscale method can still well reproduce the shear stress profile, the mean separation curve, and the transverse stress profile obtained from the fully atomistic simulation for the system.
18. Theoretical reconstruction of realistic dynamics of highly coarse-grained cis-1,4-polybutadiene melts.
PubMed
Lyubimov, I Y; Guenza, M G
2013-03-28
The theory to reconstruct the atomistic-level chain diffusion from the accelerated dynamics that is measured in mesoscale simulations of the coarse-grained system, is applied here to the dynamics of cis-1,4-polybutadiene melts where each chain is described as a soft interacting colloidal particle. The rescaling formalism accounts for the corrections in the dynamics due to the change in entropy and the change in friction that are a consequence of the coarse-graining procedure. By including these two corrections the dynamics is rescaled to reproduce the realistic dynamics of the system described at the atomistic level. The rescaled diffusion coefficient obtained from mesoscale simulations of coarse-grained cis-1,4-polybutadiene melts shows good agreement with data from united atom simulations performed by Tsolou et al. [Macromolecules 38, 1478 (2005)]. The derived monomer friction coefficient is used as an input to the theory for cooperative dynamics that describes the internal dynamics of a polymer moving in a transient regions of slow cooperative motion in a liquid of macromolecules. Theoretically predicted time correlation functions show good agreement with simulations in the whole range of length and time scales in which data are available. PMID:23556797
19. A simple and transferable all-atom/coarse-grained hybrid model to study membrane processes.
PubMed
Genheden, Samuel; Essex, Jonathan W
2015-10-13
We present an efficient all-atom/coarse-grained hybrid model and apply it to membrane processes. This model is an extension of the all-atom/ELBA model applied previously to processes in water. Here, we improve the efficiency of the model by implementing a multiple-time step integrator that allows the atoms and the coarse-grained beads to be propagated at different timesteps. Furthermore, we fine-tune the interaction between the atoms and the coarse-grained beads by computing the potential of mean force of amino acid side chain analogs along the membrane normal and comparing to atomistic simulations. The model was independently validated on the calculation of small-molecule partition coefficients. Finally, we apply the model to membrane peptides. We studied the tilt angle of the Walp23 and Kalp23 helices in two different model membranes and the stability of the glycophorin A dimer. The model is efficient, accurate, and straightforward to use, as it does not require any extra interaction particles, layers of atomistic solvent molecules or tabulated potentials, thus offering a novel, simple approach to study membrane processes. PMID:26574264
20. Adaptive resolution simulation of polarizable supramolecular coarse-grained water models
SciTech Connect
Zavadlav, Julija; Praprotnik, Matej; Melo, Manuel N.; Marrink, Siewert J.
2015-06-28
Multiscale simulations methods, such as adaptive resolution scheme, are becoming increasingly popular due to their significant computational advantages with respect to conventional atomistic simulations. For these kind of simulations, it is essential to develop accurate multiscale water models that can be used to solvate biophysical systems of interest. Recently, a 4-to-1 mapping was used to couple the bundled-simple point charge water with the MARTINI model. Here, we extend the supramolecular mapping to coarse-grained models with explicit charges. In particular, the two tested models are the polarizable water and big multiple water models associated with the MARTINI force field. As corresponding coarse-grained representations consist of several interaction sites, we couple orientational degrees of freedom of the atomistic and coarse-grained representations via a harmonic energy penalty term. This additional energy term aligns the dipole moments of both representations. We test this coupling by studying the system under applied static external electric field. We show that our approach leads to the correct reproduction of the relevant structural and dynamical properties.
1. Phase Separation Behavior of Mixed Lipid Systems at Neutral and Low pH: Coarse-Grained Simulations with DMD/LIME
PubMed Central
2015-01-01
We extend LIME, an intermediate resolution, implicit solvent model for phospholipids previously used in discontinuous molecular dynamics simulations of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) bilayer formation at 325 K, to the description of the geometry and energetics of 1,2-distearoyl-sn-glycero-3-phospho-l-serine (DSPS) and 1,2-dihenarachidoyl-sn-glycero-3-phosphocholine (21PC) and mixtures thereof at both neutral and low pH at 310 K. A multiscale modeling approach is used to calculate the LIME parameters from atomistic simulation data on a mixed DPPC/DSPS system at different pH values. In the model, 17 coarse-grained sites represent DSPS and 18 coarse-grained sites represent 21PC. Each of these coarse-grained sites is classified as 1 of 9 types. LIME/DMD simulations of equimolar bilayers show the following: (1) 21PC/DSPS bilayers with and without surface area restrictions separate faster at low pH than at neutral pH, (2) 21PC/DSPS systems separate at approximately the same rate regardless of whether they are subjected to surface area restrictions, and (3) bilayers with a molar ratio of 9:1 (21PC:DSPS) phase separate to form heterogeneous domains faster at low pH than at neutral pH. Our results are consistent with experimental findings of Sofou and co-workers (Bandekar et al. Mol. Pharmaceutics, 2013, 10, 152–160; Karve et al. Biomaterials, 2010, 31, 4409–4416) that more doxorubicin is released from 21PC/DSPS liposomes at low pH than at neutral pH, presumably because greater phase separation is achieved at low pH than at neutral pH. These are the first molecular-level simulations of the phase separation in mixed lipid bilayers induced by a change in pH. PMID:25549801
2. Peridynamics as a rigorous coarse-graining of atomistics for multiscale materials design.
SciTech Connect
Lehoucq, Richard B.; Aidun, John Bahram; Silling, Stewart Andrew; Sears, Mark P.; Kamm, James R.; Parks, Michael L.
2010-09-01
This report summarizes activities undertaken during FY08-FY10 for the LDRD Peridynamics as a Rigorous Coarse-Graining of Atomistics for Multiscale Materials Design. The goal of our project was to develop a coarse-graining of finite temperature molecular dynamics (MD) that successfully transitions from statistical mechanics to continuum mechanics. The goal of our project is to develop a coarse-graining of finite temperature molecular dynamics (MD) that successfully transitions from statistical mechanics to continuum mechanics. Our coarse-graining overcomes the intrinsic limitation of coupling atomistics with classical continuum mechanics via the FEM (finite element method), SPH (smoothed particle hydrodynamics), or MPM (material point method); namely, that classical continuum mechanics assumes a local force interaction that is incompatible with the nonlocal force model of atomistic methods. Therefore FEM, SPH, and MPM inherit this limitation. This seemingly innocuous dichotomy has far reaching consequences; for example, classical continuum mechanics cannot resolve the short wavelength behavior associated with atomistics. Other consequences include spurious forces, invalid phonon dispersion relationships, and irreconcilable descriptions/treatments of temperature. We propose a statistically based coarse-graining of atomistics via peridynamics and so develop a first of a kind mesoscopic capability to enable consistent, thermodynamically sound, atomistic-to-continuum (AtC) multiscale material simulation. Peridynamics (PD) is a microcontinuum theory that assumes nonlocal forces for describing long-range material interaction. The force interactions occurring at finite distances are naturally accounted for in PD. Moreover, PDs nonlocal force model is entirely consistent with those used by atomistics methods, in stark contrast to classical continuum mechanics. Hence, PD can be employed for mesoscopic phenomena that are beyond the realms of classical continuum mechanics and
3. Coarse-grained simulations of polyelectrolyte complexes: MARTINI models for poly(styrene sulfonate) and poly(diallyldimethylammonium)
SciTech Connect
Vögele, Martin; Holm, Christian; Smiatek, Jens
2015-12-28
We present simulations of aqueous polyelectrolyte complexes with new MARTINI models for the charged polymers poly(styrene sulfonate) and poly(diallyldimethylammonium). Our coarse-grained polyelectrolyte models allow us to study large length and long time scales with regard to chemical details and thermodynamic properties. The results are compared to the outcomes of previous atomistic molecular dynamics simulations and verify that electrostatic properties are reproduced by our MARTINI coarse-grained approach with reasonable accuracy. Structural similarity between the atomistic and the coarse-grained results is indicated by a comparison between the pair radial distribution functions and the cumulative number of surrounding particles. Our coarse-grained models are able to quantitatively reproduce previous findings like the correct charge compensation mechanism and a reduced dielectric constant of water. These results can be interpreted as the underlying reason for the stability of polyelectrolyte multilayers and complexes and validate the robustness of the proposed models.
4. Chondrules, matrix and coarse-grained chondrule rims in the allende meteorite: origin, interrelationships and possible precursor components
SciTech Connect
Rubin, A.E.; Wasson, J.T.
1987-07-01
Bulk compositions of 20 chondrules, 13 coarse-grained chondrule rims and two composite samples of matrix material from CV3 Allende were determined by instrumental neutron activation analysis. Three rare nonporphyritic CV chondrules (from Allende, Leoville and Vigarano) were analyzed by broad-beam electron microprobe analysis. Chondrule precursor components deduced from chondrule compositions are characterized by: (1) refractory and semi-refractory lithophiles with low FeO, (2) common siderophiles and chalcophiles, (3) common to slightly volatile lithophiles (Si, Cr, Mn), and modal pyroxene with moderately high FeO/(FeO + MgO), (4) moderately volatile siderophiles and (5) alkalies. These precursor components can be explained by plausible processes occurring in the solar nebula. In general, the compositions of coarse-grained rims are more similar to the mean chondrule composition than to those of the chondrules they enclose. Several chondrules and rims have fractionated rare-earth patterns and may have been affected by metamorphism. The enclosure of some coarse-grained rims by fine-grained matrix-like rims indicates that coarse-grained rims were also formed in the nebula. Two matrix samples are similar in composition to some coarse-grained rims, suggesting that matrix was derived from similar compositional reservoirs of nebular dust. Chondrules with coarse-grained rims were reheated in space following the accretion of dusty coatings.
5. Hydrodynamic interactions and Brownian forces in colloidal suspensions: Coarse-graining over time and length scales
Padding, J. T.; Louis, A. A.
2006-09-01
We describe in detail how to implement a coarse-grained hybrid molecular dynamics and stochastic rotation dynamics simulation technique that captures the combined effects of Brownian and hydrodynamic forces in colloidal suspensions. The importance of carefully tuning the simulation parameters to correctly resolve the multiple time and length scales of this problem is emphasized. We systematically analyze how our coarse-graining scheme resolves dimensionless hydrodynamic numbers such as the Reynolds number Re, which indicates the importance of inertial effects, the Schmidt number Sc, which indicates whether momentum transport is liquidlike or gaslike, the Mach number, which measures compressibility effects, the Knudsen number, which describes the importance of noncontinuum molecular effects, and the Peclet number, which describes the relative effects of convective and diffusive transport. With these dimensionless numbers in the correct regime the many Brownian and hydrodynamic time scales can be telescoped together to maximize computational efficiency while still correctly resolving the physically relevant processes. We also show how to control a number of numerical artifacts, such as finite-size effects and solvent-induced attractive depletion interactions. When all these considerations are properly taken into account, the measured colloidal velocity autocorrelation functions and related self-diffusion and friction coefficients compare quantitatively with theoretical calculations. By contrast, these calculations demonstrate that, notwithstanding its seductive simplicity, the basic Langevin equation does a remarkably poor job of capturing the decay rate of the velocity autocorrelation function in the colloidal regime, strongly underestimating it at short times and strongly overestimating it at long times. Finally, we discuss in detail how to map the parameters of our method onto physical systems and from this extract more general lessons—keeping in mind that there
6. Hydrodynamic interactions and Brownian forces in colloidal suspensions: coarse-graining over time and length scales.
PubMed
Padding, J T; Louis, A A
2006-09-01
We describe in detail how to implement a coarse-grained hybrid molecular dynamics and stochastic rotation dynamics simulation technique that captures the combined effects of Brownian and hydrodynamic forces in colloidal suspensions. The importance of carefully tuning the simulation parameters to correctly resolve the multiple time and length scales of this problem is emphasized. We systematically analyze how our coarse-graining scheme resolves dimensionless hydrodynamic numbers such as the Reynolds number Re, which indicates the importance of inertial effects, the Schmidt number Sc, which indicates whether momentum transport is liquidlike or gaslike, the Mach number, which measures compressibility effects, the Knudsen number, which describes the importance of noncontinuum molecular effects, and the Peclet number, which describes the relative effects of convective and diffusive transport. With these dimensionless numbers in the correct regime the many Brownian and hydrodynamic time scales can be telescoped together to maximize computational efficiency while still correctly resolving the physically relevant processes. We also show how to control a number of numerical artifacts, such as finite-size effects and solvent-induced attractive depletion interactions. When all these considerations are properly taken into account, the measured colloidal velocity autocorrelation functions and related self-diffusion and friction coefficients compare quantitatively with theoretical calculations. By contrast, these calculations demonstrate that, notwithstanding its seductive simplicity, the basic Langevin equation does a remarkably poor job of capturing the decay rate of the velocity autocorrelation function in the colloidal regime, strongly underestimating it at short times and strongly overestimating it at long times. Finally, we discuss in detail how to map the parameters of our method onto physical systems and from this extract more general lessons-keeping in mind that there
7. Markov state modeling and dynamical coarse-graining via discrete relaxation path sampling
Fačkovec, B.; Vanden-Eijnden, E.; Wales, D. J.
2015-07-01
A method is derived to coarse-grain the dynamics of complex molecular systems to a Markov jump process (MJP) describing how the system jumps between cells that fully partition its state space. The main inputs are relaxation times for each pair of cells, which are shown to be robust with respect to positioning of the cell boundaries. These relaxation times can be calculated via molecular dynamics simulations performed in each cell separately and are used in an efficient estimator for the rate matrix of the MJP. The method is illustrated through applications to Sinai billiards and a cluster of Lennard-Jones discs.
8. Dynamic force matching: A method for constructing dynamical coarse-grained models with realistic time dependence
SciTech Connect
Davtyan, Aram; Dama, James F.; Voth, Gregory A.; Andersen, Hans C.
2015-04-21
Coarse-grained (CG) models of molecular systems, with fewer mechanical degrees of freedom than an all-atom model, are used extensively in chemical physics. It is generally accepted that a coarse-grained model that accurately describes equilibrium structural properties (as a result of having a well constructed CG potential energy function) does not necessarily exhibit appropriate dynamical behavior when simulated using conservative Hamiltonian dynamics for the CG degrees of freedom on the CG potential energy surface. Attempts to develop accurate CG dynamic models usually focus on replacing Hamiltonian motion by stochastic but Markovian dynamics on that surface, such as Langevin or Brownian dynamics. However, depending on the nature of the system and the extent of the coarse-graining, a Markovian dynamics for the CG degrees of freedom may not be appropriate. In this paper, we consider the problem of constructing dynamic CG models within the context of the Multi-Scale Coarse-graining (MS-CG) method of Voth and coworkers. We propose a method of converting a MS-CG model into a dynamic CG model by adding degrees of freedom to it in the form of a small number of fictitious particles that interact with the CG degrees of freedom in simple ways and that are subject to Langevin forces. The dynamic models are members of a class of nonlinear systems interacting with special heat baths that were studied by Zwanzig [J. Stat. Phys. 9, 215 (1973)]. The properties of the fictitious particles can be inferred from analysis of the dynamics of all-atom simulations of the system of interest. This is analogous to the fact that the MS-CG method generates the CG potential from analysis of equilibrium structures observed in all-atom simulation data. The dynamic models generate a non-Markovian dynamics for the CG degrees of freedom, but they can be easily simulated using standard molecular dynamics programs. We present tests of this method on a series of simple examples that demonstrate that
9. Markov state modeling and dynamical coarse-graining via discrete relaxation path sampling.
PubMed
Fačkovec, B; Vanden-Eijnden, E; Wales, D J
2015-07-28
A method is derived to coarse-grain the dynamics of complex molecular systems to a Markov jump process (MJP) describing how the system jumps between cells that fully partition its state space. The main inputs are relaxation times for each pair of cells, which are shown to be robust with respect to positioning of the cell boundaries. These relaxation times can be calculated via molecular dynamics simulations performed in each cell separately and are used in an efficient estimator for the rate matrix of the MJP. The method is illustrated through applications to Sinai billiards and a cluster of Lennard-Jones discs. PMID:26233119
10. RedMDStream: Parameterization and Simulation Toolbox for Coarse-Grained Molecular Dynamics Models
PubMed Central
Leonarski, Filip; Trylska, Joanna
2015-01-01
Coarse-grained (CG) models in molecular dynamics (MD) are powerful tools to simulate the dynamics of large biomolecular systems on micro- to millisecond timescales. However, the CG model, potential energy terms, and parameters are typically not transferable between different molecules and problems. So parameterizing CG force fields, which is both tedious and time-consuming, is often necessary. We present RedMDStream, a software for developing, testing, and simulating biomolecules with CG MD models. Development includes an automatic procedure for the optimization of potential energy parameters based on metaheuristic methods. As an example we describe the parameterization of a simple CG MD model of an RNA hairpin. PMID:25902423
11. Morphological study of near threshold fatigue crack growth in a coarse grain aluminum alloy
NASA Technical Reports Server (NTRS)
Maurer, Gerhard; Liu, H. W.
1984-01-01
Fatigue crack propagation in the near-threshold region has been studied in coarse grain Al 7029 alloy. Over eighty percent of the crack surfaces are planar areas parallel to either 100-oriented or 111-oriented planes. The 100-plane crack surfaces show 'pine tree' morphological features formed by slip on two sets of intersecting planes. The 111-plane crack surfaces were planar and shiny. They were formed primarily by slip on a single dominant 111-oriented slip plane with sparse and very light secondary slip markings. Crack growth rates were measured and correlated with Delta-K.
12. Entanglement of a coarse grained quantum field in the expanding universe
SciTech Connect
2009-12-15
We investigate the entanglement of a quantum field in the expanding universe. By introducing a bipartite system using a coarse-grained scalar field, we apply the separability criterion based on the partial transpose operation and numerically calculate the bipartite entanglement between separate spatial regions. We find that the initial entangled state becomes separable or disentangled after the spatial separation of two points exceed the Hubble horizon. This provides the necessary conditions for the appearance of classicality of the quantum fluctuation. We also investigate the condition of classicality that the quantum field can be treated as the classical stochastic variables.
13. Coarse-grained particle model for pedestrian flow using diffusion maps
Marschler, Christian; Starke, Jens; Liu, Ping; Kevrekidis, Ioannis G.
2014-01-01
Interacting particle systems constitute the dynamic model of choice in a variety of application areas. A prominent example is pedestrian dynamics, where good design of escape routes for large buildings and public areas can improve evacuation in emergency situations, avoiding exit blocking and the ensuing panic. Here we employ diffusion maps to study the coarse-grained dynamics of two pedestrian crowds trying to pass through a door from opposite sides. These macroscopic variables and the associated smooth embeddings lead to a better description and a clearer understanding of the nature of the transition to oscillatory dynamics. We also compare the results to those obtained through intuitively chosen macroscopic variables.
14. A coarse-graining approach for the proton complex in protonated aluminosilicates.
PubMed
Calero, S; Lobato, M D; García-Pérez, E; Mejías, J A; Lago, S; Vlugt, T J H; Maesen, T L M; Smit, B; Dubbeldam, D
2006-03-30
We have developed a computational framework for the adsorption of linear alkanes in protonated aluminosilicates. These zeolites contain trace amounts of water that form hydrated proton complexes. The presence of hydrated protons makes the simulations at the fully atomistic level difficult. Instead of constructing an elaborate and complex model, we show that an approach based on a coarse-graining of the proton-complex accurately describes the available experimental isotherms, Henry coefficients, heats of adsorption, and oxygen-proton distances. Our approach is supported by MP2 quantum mechanical simulations. The model gives remarkably good agreement with experimental data beyond the initial calibration set.
15. Dynamic force matching: A method for constructing dynamical coarse-grained models with realistic time dependence
Davtyan, Aram; Dama, James F.; Voth, Gregory A.; Andersen, Hans C.
2015-04-01
Coarse-grained (CG) models of molecular systems, with fewer mechanical degrees of freedom than an all-atom model, are used extensively in chemical physics. It is generally accepted that a coarse-grained model that accurately describes equilibrium structural properties (as a result of having a well constructed CG potential energy function) does not necessarily exhibit appropriate dynamical behavior when simulated using conservative Hamiltonian dynamics for the CG degrees of freedom on the CG potential energy surface. Attempts to develop accurate CG dynamic models usually focus on replacing Hamiltonian motion by stochastic but Markovian dynamics on that surface, such as Langevin or Brownian dynamics. However, depending on the nature of the system and the extent of the coarse-graining, a Markovian dynamics for the CG degrees of freedom may not be appropriate. In this paper, we consider the problem of constructing dynamic CG models within the context of the Multi-Scale Coarse-graining (MS-CG) method of Voth and coworkers. We propose a method of converting a MS-CG model into a dynamic CG model by adding degrees of freedom to it in the form of a small number of fictitious particles that interact with the CG degrees of freedom in simple ways and that are subject to Langevin forces. The dynamic models are members of a class of nonlinear systems interacting with special heat baths that were studied by Zwanzig [J. Stat. Phys. 9, 215 (1973)]. The properties of the fictitious particles can be inferred from analysis of the dynamics of all-atom simulations of the system of interest. This is analogous to the fact that the MS-CG method generates the CG potential from analysis of equilibrium structures observed in all-atom simulation data. The dynamic models generate a non-Markovian dynamics for the CG degrees of freedom, but they can be easily simulated using standard molecular dynamics programs. We present tests of this method on a series of simple examples that demonstrate that
16. Coarse grained molecular dynamics and theoretical studies of carbon nanotubes entering cell membrane
Shi, Xinghua; Kong, Yong; Gao, Huajian
2008-04-01
Motivated by recent experimental observations that carbon nanotubes (CNT) can enter animal cells, here we conduct coarse grained molecular dynamics and theoretical studies of the intrinsic interaction mechanisms between CNT’s and lipid bilayer. The results indicate that CNT-cell interaction is dominated by van der Waals and hydrophobic forces, and that CNT’s with sufficiently small radii can directly pierce through cell membrane while larger tubes tend to enter cell via a wrapping mechanism. Theoretical models are proposed to explain the observed size effect in transition of entry mechanisms.
17. Temporal coarse-graining method to simulate the movement of atoms
SciTech Connect
Ichinomiya, Takashi
2013-10-15
We propose a novel method to simulate the movement of atoms at finite temperature. The main idea of our method is to derive “renormalized,” or coarse-grained in time, dynamics from the Euler–Maruyama scheme, which is the standard method for solving the stochastic differential equations numerically. Based on this renormalization, we propose a new algorithm for solving overdamped Langevin equations. We test our renormalization scheme on two models and demonstrate that the results obtained by this method are consistent with those obtained by the standard method. Our algorithm performs better than the standard scheme, especially at low temperatures and with multiple processors.
18. Towards a unified framework for coarse-graining particle-based simulations.
SciTech Connect
Junghans, Christoph
2012-06-28
Different coarse-graining techniques for soft matter systems have been developed in recent years, however it is often very demanding to find the method most suitable for the problem studied. For this reason we began to develop the VOTCA toolkit to allow for easy comparison of different methods. We have incorporated 6 different techniques into the package and implemented a powerful and parallel analysis framework plus multiple simulation back-ends. We will discuss the specifics of the package by means of various studies, which have been performed with the toolkit and highlight problems we encountered along the way.
19. Derivation of coarse-grained simulation models of chlorophyll molecules in lipid bilayers for applications in light harvesting systems.
PubMed
Debnath, Ananya; Wiegand, Sabine; Paulsen, Harald; Kremer, Kurt; Peter, Christine
2015-09-14
The correct interplay of interactions between protein, pigment and lipid molecules is highly relevant for our understanding of the association behavior of the light harvesting complex (LHCII) of green plants. To cover the relevant time and length scales in this multicomponent system, a multi-scale simulation ansatz is employed that subsequently uses a classical all atomistic (AA) model to derive a suitable coarse grained (CG) model which can be backmapped into the AA resolution, aiming for a seamless conversion between two scales. Such an approach requires a faithful description of not only the protein and lipid components, but also the interaction functions for the indispensable pigment molecules, chlorophyll b and chlorophyll a (referred to as chl b/chl a). In this paper we develop a CG model for chl b and chl a in a dipalmitoylphosphatidyl choline (DPPC) bilayer system. The structural properties and the distribution behavior of chl within the lipid bilayer in the CG simulations are consistent with those of AA reference simulations. The non-bonded potentials are parameterized such that they fit to the thermodynamics based MARTINI force-field for the lipid bilayer and the protein. The CG simulation shows chl aggregation in the lipid bilayer which is supported by fluorescence quenching experiments. It is shown that the derived chl model is well suited for CG simulations of stable, structurally consistent, trimeric LHCII and can in the future be used to study their large scale aggregation behavior.
20. Coupling a nano-particle with isothermal fluctuating hydrodynamics: Coarse-graining from microscopic to mesoscopic dynamics.
PubMed
Español, Pep; Donev, Aleksandar
2015-12-21
We derive a coarse-grained description of the dynamics of a nanoparticle immersed in an isothermal simple fluid by performing a systematic coarse graining of the underlying microscopic dynamics. As coarse-grained or relevant variables, we select the position of the nanoparticle and the total mass and momentum density field of the fluid, which are locally conserved slow variables because they are defined to include the contribution of the nanoparticle. The theory of coarse graining based on the Zwanzing projection operator leads us to a system of stochastic ordinary differential equations that are closed in the relevant variables. We demonstrate that our discrete coarse-grained equations are consistent with a Petrov-Galerkin finite-element discretization of a system of formal stochastic partial differential equations which resemble previously used phenomenological models based on fluctuating hydrodynamics. Key to this connection between our "bottom-up" and previous "top-down" approaches is the use of the same dual orthogonal set of linear basis functions familiar from finite element methods (FEMs), both as a way to coarse-grain the microscopic degrees of freedom and as a way to discretize the equations of fluctuating hydrodynamics. Another key ingredient is the use of a "linear for spiky" weak approximation which replaces microscopic "fields" with a linear FE interpolant inside expectation values. For the irreversible or dissipative dynamics, we approximate the constrained Green-Kubo expressions for the dissipation coefficients with their equilibrium averages. Under suitable approximations, we obtain closed approximations of the coarse-grained dynamics in a manner which gives them a clear physical interpretation and provides explicit microscopic expressions for all of the coefficients appearing in the closure. Our work leads to a model for dilute nanocolloidal suspensions that can be simulated effectively using feasibly short molecular dynamics simulations as input
1. Coupling a nano-particle with isothermal fluctuating hydrodynamics: Coarse-graining from microscopic to mesoscopic dynamics
SciTech Connect
Español, Pep; Donev, Aleksandar
2015-12-21
We derive a coarse-grained description of the dynamics of a nanoparticle immersed in an isothermal simple fluid by performing a systematic coarse graining of the underlying microscopic dynamics. As coarse-grained or relevant variables, we select the position of the nanoparticle and the total mass and momentum density field of the fluid, which are locally conserved slow variables because they are defined to include the contribution of the nanoparticle. The theory of coarse graining based on the Zwanzing projection operator leads us to a system of stochastic ordinary differential equations that are closed in the relevant variables. We demonstrate that our discrete coarse-grained equations are consistent with a Petrov-Galerkin finite-element discretization of a system of formal stochastic partial differential equations which resemble previously used phenomenological models based on fluctuating hydrodynamics. Key to this connection between our “bottom-up” and previous “top-down” approaches is the use of the same dual orthogonal set of linear basis functions familiar from finite element methods (FEMs), both as a way to coarse-grain the microscopic degrees of freedom and as a way to discretize the equations of fluctuating hydrodynamics. Another key ingredient is the use of a “linear for spiky” weak approximation which replaces microscopic “fields” with a linear FE interpolant inside expectation values. For the irreversible or dissipative dynamics, we approximate the constrained Green-Kubo expressions for the dissipation coefficients with their equilibrium averages. Under suitable approximations, we obtain closed approximations of the coarse-grained dynamics in a manner which gives them a clear physical interpretation and provides explicit microscopic expressions for all of the coefficients appearing in the closure. Our work leads to a model for dilute nanocolloidal suspensions that can be simulated effectively using feasibly short molecular dynamics
2. Coupling a nano-particle with isothermal fluctuating hydrodynamics: Coarse-graining from microscopic to mesoscopic dynamics.
PubMed
Español, Pep; Donev, Aleksandar
2015-12-21
We derive a coarse-grained description of the dynamics of a nanoparticle immersed in an isothermal simple fluid by performing a systematic coarse graining of the underlying microscopic dynamics. As coarse-grained or relevant variables, we select the position of the nanoparticle and the total mass and momentum density field of the fluid, which are locally conserved slow variables because they are defined to include the contribution of the nanoparticle. The theory of coarse graining based on the Zwanzing projection operator leads us to a system of stochastic ordinary differential equations that are closed in the relevant variables. We demonstrate that our discrete coarse-grained equations are consistent with a Petrov-Galerkin finite-element discretization of a system of formal stochastic partial differential equations which resemble previously used phenomenological models based on fluctuating hydrodynamics. Key to this connection between our "bottom-up" and previous "top-down" approaches is the use of the same dual orthogonal set of linear basis functions familiar from finite element methods (FEMs), both as a way to coarse-grain the microscopic degrees of freedom and as a way to discretize the equations of fluctuating hydrodynamics. Another key ingredient is the use of a "linear for spiky" weak approximation which replaces microscopic "fields" with a linear FE interpolant inside expectation values. For the irreversible or dissipative dynamics, we approximate the constrained Green-Kubo expressions for the dissipation coefficients with their equilibrium averages. Under suitable approximations, we obtain closed approximations of the coarse-grained dynamics in a manner which gives them a clear physical interpretation and provides explicit microscopic expressions for all of the coefficients appearing in the closure. Our work leads to a model for dilute nanocolloidal suspensions that can be simulated effectively using feasibly short molecular dynamics simulations as input
3. Two-Component Coarse-Grained Molecular-Dynamics Model for the Human Erythrocyte Membrane
PubMed Central
Li, He; Lykotrafitis, George
2012-01-01
We present a two-component coarse-grained molecular-dynamics model for simulating the erythrocyte membrane. The proposed model possesses the key feature of combing the lipid bilayer and the erythrocyte cytoskeleton, thus showing both the fluidic behavior of the lipid bilayer and the elastic properties of the erythrocyte cytoskeleton. In this model, three types of coarse-grained particles are introduced to represent clusters of lipid molecules, actin junctions, and band-3 complexes, respectively. The proposed model facilitates simulations that span large length scales (approximately micrometers) and timescales (approximately milliseconds). By tuning the interaction potential parameters, we were able to control the diffusivity and bending rigidity of the membrane model. We studied the membrane under shearing and found that at a low shear strain rate, the developed shear stress was due mainly to the spectrin network, whereas the viscosity of the lipid bilayer contributed to the resulting shear stress at higher strain rates. In addition, we investigated the effects of a reduced spectrin network connectivity on the shear modulus of the membrane. PMID:22225800
4. Path statistics, memory, and coarse-graining of continuous-time random walks on networks
Manhart, Michael; Kion-Crosby, Willow; Morozov, Alexandre V.
2015-12-01
Continuous-time random walks (CTRWs) on discrete state spaces, ranging from regular lattices to complex networks, are ubiquitous across physics, chemistry, and biology. Models with coarse-grained states (for example, those employed in studies of molecular kinetics) or spatial disorder can give rise to memory and non-exponential distributions of waiting times and first-passage statistics. However, existing methods for analyzing CTRWs on complex energy landscapes do not address these effects. Here we use statistical mechanics of the nonequilibrium path ensemble to characterize first-passage CTRWs on networks with arbitrary connectivity, energy landscape, and waiting time distributions. Our approach can be applied to calculating higher moments (beyond the mean) of path length, time, and action, as well as statistics of any conservative or non-conservative force along a path. For homogeneous networks, we derive exact relations between length and time moments, quantifying the validity of approximating a continuous-time process with its discrete-time projection. For more general models, we obtain recursion relations, reminiscent of transfer matrix and exact enumeration techniques, to efficiently calculate path statistics numerically. We have implemented our algorithm in PathMAN (Path Matrix Algorithm for Networks), a Python script that users can apply to their model of choice. We demonstrate the algorithm on a few representative examples which underscore the importance of non-exponential distributions, memory, and coarse-graining in CTRWs.
5. Polymer-solid contacts described by soft, coarse-grained models.
PubMed
Müller, Marcus; Steinmüller, Birger; Daoulas, Kostas Ch; Ramírez-Hernández, Abelardo; de Pablo, Juan J
2011-06-14
The ability of soft, coarse-grained models to describe the narrow interface of a nearly incompressible polymer melt in contact with a solid is explored by numerical self-consistent field calculations and Monte-Carlo simulations. We investigate the effect of the discreteness of the bead-spring architecture by quantitatively comparing the results of a bead-spring model with different number of beads, N, but identical end-to-end distance, R(e), and a continuous Gaussian-thread model. If the width, ξ, of the narrow polymer-solid contact is smaller or comparable to the length of a statistical segment, b=R(e)/√N-1, strong differences in the interface tension and the density profiles between the two models are observed, and strategies for compensating the discrete nature of the bead-spring model are investigated. Compensating the discretization of the chain contour in the bead-spring model by applying an external segment-solid potential, we simultaneously adjust the interface tension and the density profile to the predictions of the Gaussian-thread model. We suggest that the geometry of the polymer-solid contact and the interface tension are relevant characteristics that a coarse-grained model of polymer-solid contacts must reproduce in order to establish a quantitative relationship to an experimental system.
6. Simulation of ballistic performance of coarse-grained metals strengthened by nanotwinned regions
Yang, G.; Guo, X.; Weng, G. J.; Zhu, L. L.; Ji, R.
2015-12-01
Coarse-grained (CG) metals strengthened by nanotwinned (NT) regions have both ultrahigh strength and good ductility. The presence of the NT regions contributes to their ultrahigh strength, while their good ductility is attributed to the recrystallized coarse grains. These characteristics make them a potential candidate for bullet-proof material. In this paper, numerical simulations based on the mechanism-based strain gradient plasticity and the Johnson-Cook failure criterion are carried out to investigate the effects of twin spacing and microstructural attributes on the ballistic performance of CG copper strengthened by NT regions. We investigate the performance of fourteen idealized microstructures, and find that smaller twin spacing and regular distribution of NT regions are more conducive to the promotion of the ballistic performance. We also uncover that the role of the shape of NT regions is significantly affected by twin spacing. Furthermore, we make a comparison with its CG counterpart without NTs, and find that microstructures with array arrangement of NT regions have higher limit velocities and smaller relative displacements than the single phase CG structure. This makes them a strong candidate for helmets and other personal protective equipments. It is believed that the simulated results could provide useful insights into the development of this advanced class of metals for ballistic protection.
7. Contrasting Polymer Behavior Under Nanoconfinement using Thermomechanically Consistent Coarse-Grained Models
Keten, Sinan; Xia, Wenjie; Hsu, David
2015-03-01
We present a systematic, two-bead per monomer coarse graining strategy that simulates the thermomechanical behavior of polymers several hundred times faster than all-atom MD (Hsu et al. JCTC, 2014). The predictive capability of the technique is illustrated here for 5 different methacrylate monomers and polystyrene stereoisomers. The approach involves optimization of analytical bonded potentials from atomistic bonded distributions to emulate local structure, as validated by chain end-to-end length and the radius of gyration comparisons with experiments and random coil theory. Nonbonded Lennard-Jones potentials are tuned to reproduce the elastic modulus (E) and glass transition temperature (Tg) at a single thermodynamic state. Density-corrected parameters capture temperature-modulus dependence in the 150-600 K range. Flory-Fox constants of the CG models are commensurate with all atomistic and experimental results, even though all calibrations are done at a single molecular weight. Finally, we further demonstrate the predictive capabilities of the models by examining thin film nanoconfinement effects for different polymers, film thicknesses, interfacial energies, and molecular weights. Our technique, called thermomechanically consistent coarse graining (TCCG), is demonstrated, using polystyrene and poly(methylmethacrylate) as universal benchmarks, to be a robust and effective technique to understand the thermomechanical behavior of polymers thin films and nanocomposites.
8. Incorporation of memory effects in coarse-grained modeling via the Mori-Zwanzig formalism.
PubMed
Li, Zhen; Bian, Xin; Li, Xiantao; Karniadakis, George Em
2015-12-28
The Mori-Zwanzig formalism for coarse-graining a complex dynamical system typically introduces memory effects. The Markovian assumption of delta-correlated fluctuating forces is often employed to simplify the formulation of coarse-grained (CG) models and numerical implementations. However, when the time scales of a system are not clearly separated, the memory effects become strong and the Markovian assumption becomes inaccurate. To this end, we incorporate memory effects into CG modeling by preserving non-Markovian interactions between CG variables, and the memory kernel is evaluated directly from microscopic dynamics. For a specific example, molecular dynamics (MD) simulations of star polymer melts are performed while the corresponding CG system is defined by grouping many bonded atoms into single clusters. Then, the effective interactions between CG clusters as well as the memory kernel are obtained from the MD simulations. The constructed CG force field with a memory kernel leads to a non-Markovian dissipative particle dynamics (NM-DPD). Quantitative comparisons between the CG models with Markovian and non-Markovian approximations indicate that including the memory effects using NM-DPD yields similar results as the Markovian-based DPD if the system has clear time scale separation. However, for systems with small separation of time scales, NM-DPD can reproduce correct short-time properties that are related to how the system responds to high-frequency disturbances, which cannot be captured by the Markovian-based DPD model. PMID:26723613
9. Incorporation of memory effects in coarse-grained modeling via the Mori-Zwanzig formalism
Li, Zhen; Bian, Xin; Li, Xiantao; Karniadakis, George Em
2015-12-01
The Mori-Zwanzig formalism for coarse-graining a complex dynamical system typically introduces memory effects. The Markovian assumption of delta-correlated fluctuating forces is often employed to simplify the formulation of coarse-grained (CG) models and numerical implementations. However, when the time scales of a system are not clearly separated, the memory effects become strong and the Markovian assumption becomes inaccurate. To this end, we incorporate memory effects into CG modeling by preserving non-Markovian interactions between CG variables, and the memory kernel is evaluated directly from microscopic dynamics. For a specific example, molecular dynamics (MD) simulations of star polymer melts are performed while the corresponding CG system is defined by grouping many bonded atoms into single clusters. Then, the effective interactions between CG clusters as well as the memory kernel are obtained from the MD simulations. The constructed CG force field with a memory kernel leads to a non-Markovian dissipative particle dynamics (NM-DPD). Quantitative comparisons between the CG models with Markovian and non-Markovian approximations indicate that including the memory effects using NM-DPD yields similar results as the Markovian-based DPD if the system has clear time scale separation. However, for systems with small separation of time scales, NM-DPD can reproduce correct short-time properties that are related to how the system responds to high-frequency disturbances, which cannot be captured by the Markovian-based DPD model.
10. Incorporation of memory effects in coarse-grained modeling via the Mori-Zwanzig formalism
SciTech Connect
Li, Zhen; Bian, Xin; Karniadakis, George Em; Li, Xiantao
2015-12-28
The Mori-Zwanzig formalism for coarse-graining a complex dynamical system typically introduces memory effects. The Markovian assumption of delta-correlated fluctuating forces is often employed to simplify the formulation of coarse-grained (CG) models and numerical implementations. However, when the time scales of a system are not clearly separated, the memory effects become strong and the Markovian assumption becomes inaccurate. To this end, we incorporate memory effects into CG modeling by preserving non-Markovian interactions between CG variables, and the memory kernel is evaluated directly from microscopic dynamics. For a specific example, molecular dynamics (MD) simulations of star polymer melts are performed while the corresponding CG system is defined by grouping many bonded atoms into single clusters. Then, the effective interactions between CG clusters as well as the memory kernel are obtained from the MD simulations. The constructed CG force field with a memory kernel leads to a non-Markovian dissipative particle dynamics (NM-DPD). Quantitative comparisons between the CG models with Markovian and non-Markovian approximations indicate that including the memory effects using NM-DPD yields similar results as the Markovian-based DPD if the system has clear time scale separation. However, for systems with small separation of time scales, NM-DPD can reproduce correct short-time properties that are related to how the system responds to high-frequency disturbances, which cannot be captured by the Markovian-based DPD model.
11. Coarse-grained electrostatic interactions of coronene: Towards the crystalline phase
Heinemann, Thomas; Palczynski, Karol; Dzubiella, Joachim; Klapp, Sabine H. L.
2015-11-01
In this article, we present and compare two different, coarse-grained approaches to model electrostatic interactions of disc-shaped aromatic molecules, specifically coronene. Our study builds on our previous work [T. Heinemann et al., J. Chem. Phys. 141, 214110 (2014)], where we proposed, based on a systematic coarse-graining procedure starting from the atomistic level, an anisotropic effective (Gay-Berne-like) potential capable of describing van der Waals contributions to the interaction energy. To take into account electrostatics, we introduce, first, a linear quadrupole moment along the symmetry axis of the coronene disc. The second approach takes into account the fact that the partial charges within the molecules are distributed in a ring-like fashion. We then reparametrize the effective Gay-Berne-like potential such that it matches, at short distances, the ring-ring potential. To investigate the validity of these two approaches, we perform many-particle molecular dynamics simulations, focusing on the crystalline phase (karpatite) where electrostatic interaction effects are expected to be particularly relevant for the formation of tilted stacked columns. Specifically, we investigate various structural parameters as well as the melting transition. We find that the second approach yields consistent results with those from experiments despite the fact that the underlying potential decays with the wrong distance dependence at large molecule separations. Our strategy can be transferred to a broader class of molecules, such as benzene or hexabenzocoronene.
12. Coarse-Grained Molecular Monte Carlo Simulations of Liquid Crystal-Nanoparticle Mixtures
Neufeld, Ryan; Kimaev, Grigoriy; Fu, Fred; Abukhdeir, Nasser M.
Coarse-grained intermolecular potentials have proven capable of capturing essential details of interactions between complex molecules, while substantially reducing the number of degrees of freedom of the system under study. In the domain of liquid crystals, the Gay-Berne (GB) potential has been successfully used to model the behavior of rod-like and disk-like mesogens. However, only ellipsoid-like interaction potentials can be described with GB, making it a poor fit for many real-world mesogens. In this work, the results of Monte Carlo simulations of liquid crystal domains using the Zewdie-Corner (ZC) potential are presented. The ZC potential is constructed from an orthogonal series of basis functions, allowing for potentials of essentially arbitrary shapes to be modeled. We also present simulations of mixtures of liquid crystalline mesogens with nanoparticles. Experimentally these mixtures have been observed to exhibit microphase separation and formation of long-range networks under some conditions. This highlights the need for a coarse-grained approach which can capture salient details on the molecular scale while simulating sufficiently large domains to observe these phenomena. We compare the phase behavior of our simulations with that of a recently presented continuum theory. This work was made possible by the Natural Sciences and Engineering Research Council of Canada and Compute Ontario.
13. Gay-Berne and electrostatic multipole based coarse-grain potential in implicit solvent
Wu, Johnny; Zhen, Xia; Shen, Hujun; Li, Guohui; Ren, Pengyu
2011-10-01
A general, transferable coarse-grain (CG) framework based on the Gay-Berne potential and electrostatic point multipole expansion is presented for polypeptide simulations. The solvent effect is described by the Generalized Kirkwood theory. The CG model is calibrated using the results of all-atom simulations of model compounds in solution. Instead of matching the overall effective forces produced by atomic models, the fundamental intermolecular forces such as electrostatic, repulsion-dispersion, and solvation are represented explicitly at a CG level. We demonstrate that the CG alanine dipeptide model is able to reproduce quantitatively the conformational energy of all-atom force fields in both gas and solution phases, including the electrostatic and solvation components. Replica exchange molecular dynamics and microsecond dynamic simulations of polyalanine of 5 and 12 residues reveal that the CG polyalanines fold into "alpha helix" and "beta sheet" structures. The 5-residue polyalanine displays a substantial increase in the "beta strand" fraction relative to the 12-residue polyalanine. The detailed conformational distribution is compared with those reported from recent all-atom simulations and experiments. The results suggest that the new coarse-graining approach presented in this study has the potential to offer both accuracy and efficiency for biomolecular modeling.
14. Parameterizing the Morse potential for coarse-grained modeling of blood plasma
SciTech Connect
Zhang, Na; Zhang, Peng; Kang, Wei; Bluestein, Danny; Deng, Yuefan
2014-01-15
Multiscale simulations of fluids such as blood represent a major computational challenge of coupling the disparate spatiotemporal scales between molecular and macroscopic transport phenomena characterizing such complex fluids. In this paper, a coarse-grained (CG) particle model is developed for simulating blood flow by modifying the Morse potential, traditionally used in Molecular Dynamics for modeling vibrating structures. The modified Morse potential is parameterized with effective mass scales for reproducing blood viscous flow properties, including density, pressure, viscosity, compressibility and characteristic flow dynamics of human blood plasma fluid. The parameterization follows a standard inverse-problem approach in which the optimal micro parameters are systematically searched, by gradually decoupling loosely correlated parameter spaces, to match the macro physical quantities of viscous blood flow. The predictions of this particle based multiscale model compare favorably to classic viscous flow solutions such as Counter-Poiseuille and Couette flows. It demonstrates that such coarse grained particle model can be applied to replicate the dynamics of viscous blood flow, with the advantage of bridging the gap between macroscopic flow scales and the cellular scales characterizing blood flow that continuum based models fail to handle adequately.
15. Coarse-grained simulation of lipid vesicles with n-atic'' orientational order
Geng, Jun; Selinger, Jonathan; Selinger, Robin
2012-02-01
We perform coarse-grained simulation studies of fluid lipid vesicles with in-plane n-atic'' orientational order associated with the shape of lipid head group, to test the theoretical predictions of Park, Lubensky and MacKintosh [1] for resulting vesicle shape and defect structures. Our simulation model uses a single layer coarse-grained implicit-solvent approach proposed by Yuan et al [2], with addition of an extra vector degree of freedom representing in-plane orientational order. We carry out simulation studies for n=1 to 6, examining in each case the spatial distribution of defects and resulting deformation of the vesicle. An initially spherical vesicle (genus zero) with n-atic order has a ground state with 2n vortices of strength 1/n, as expected, but the observed equilibrium shapes are sometimes quite different from those predicted theoretically. For the n=1 case, we find that the vesicle may become trapped in a disordered, long-lived metastable state with extra +/- defects whose pair-annihilation is inhibited by local changes in membrane curvature, and thus may never reach its predicted ground state. [4pt] [1] J. Park, T. C. Lubensky, and F. C. MacKintosh, Europhys. Lett. 20, 279 (1992)[0pt] [2] H. Yuan, C. Huang, Ju Li, G. Lykotrafitis, and S. Zhang, Phys. Rev. E 82, 011905 (2010)
16. Optimal matched filter design for ultrasonic NDE of coarse grain materials
Li, Minghui; Hayward, Gordon
2016-02-01
Coarse grain materials are widely used in a variety of key industrial sectors like energy, oil and gas, and aerospace due to their attractive properties. However, when these materials are inspected using ultrasound, the flaw echoes are usually contaminated by high-level, correlated grain noise originating from the material microstructures, which is time-invariant and demonstrates similar spectral characteristics as flaw signals. As a result, the reliable inspection of such materials is highly challenging. In this paper, we present a method for reliable ultrasonic non-destructive evaluation (NDE) of coarse grain materials using matched filters, where the filter is designed to approximate and match the unknown defect echoes, and a particle swarm optimization (PSO) paradigm is employed to search for the optimal parameters in the filter response with an objective to maximise the output signal-to-noise ratio (SNR). Experiments with a 128-element 5MHz transducer array on mild steel and INCONEL Alloy 617 samples are conducted, and the results confirm that the SNR of the images is improved by about 10-20 dB if the optimized matched filter is applied to all the A-scan waveforms prior to image formation. Furthermore, the matched filter can be implemented in real-time with low extra computational cost.
17. Construction of Coarse-Grained Models by Reproducing Equilibrium Probability Density Function
Lu, Shi-Jing; Zhou, Xin
2015-01-01
The present work proposes a novel methodology for constructing coarse-grained (CG) models, which aims at minimizing the difference between CG model and the corresponding original system. The difference is defined as a functional of their equilibrium conformational probability densities, then is estimated from equilibrium averages of many independent physical quantities denoted as basis functions. An orthonormalization strategy is adopted to get the independent basis functions from sufficiently preselected interesting physical quantities of the system. Thus the current method is named as probability density matching coarse-graining (PMCG) scheme, which effectively takes into account the overall characteristics of the original systems to construct CG model, and it is a natural improvement of the usual CG scheme wherein some physical quantities are intuitively chosen without considering their correlations. We verify the general PMCG framework in constructing a one-site CG water model from TIP3P model. Both structure of liquids and pressure of the TIP3P water system are found to be well reproduced at the same time in the constructed CG model.
18. Two-component coarse-grained molecular-dynamics model for the human erythrocyte membrane.
PubMed
Li, He; Lykotrafitis, George
2012-01-01
We present a two-component coarse-grained molecular-dynamics model for simulating the erythrocyte membrane. The proposed model possesses the key feature of combing the lipid bilayer and the erythrocyte cytoskeleton, thus showing both the fluidic behavior of the lipid bilayer and the elastic properties of the erythrocyte cytoskeleton. In this model, three types of coarse-grained particles are introduced to represent clusters of lipid molecules, actin junctions, and band-3 complexes, respectively. The proposed model facilitates simulations that span large length scales (approximately micrometers) and timescales (approximately milliseconds). By tuning the interaction potential parameters, we were able to control the diffusivity and bending rigidity of the membrane model. We studied the membrane under shearing and found that at a low shear strain rate, the developed shear stress was due mainly to the spectrin network, whereas the viscosity of the lipid bilayer contributed to the resulting shear stress at higher strain rates. In addition, we investigated the effects of a reduced spectrin network connectivity on the shear modulus of the membrane.
19. Coarse-grained model for the interconversion between different crystalline cellulose allomorphs
SciTech Connect
Langan, Paul
2012-01-01
We present the results of Langevin dynamics simulations on a coarse grained model for crystalline cellulose. In particular, we analyze two different cellulose crystalline forms: cellulose I (the natural form of cellulose) and cellulose IIII (obtained after cellulose I is treated with anhydrous liquid ammonia). Cellulose IIII has been the focus of wide interest in the field of cellulosic biofuels as it can be efficiently hydrolyzed to glucose (its enzymatic degradation rates are up to 5 fold higher than those of cellulose I ). In turn, glucose can eventually be fermented into fuels. The coarse-grained model presented in this study is based on a simplified geometry and on an effective potential mimicking the changes in both intracrystalline hydrogen bonds and stacking interactions during the transition from cellulose I to cellulose IIII. The model accurately reproduces both structural and thermomechanical properties of cellulose I and IIII. The work presented herein describes the structural transition from cellulose I to cellulose IIII as driven by the change in the equilibrium state of two degrees of freedom in the cellulose chains. The structural transition from cellulose I to cellulose IIII is essentially reduced to a search for optimal spatial arrangement of the cellulose chains.
20. Predicting Themomechanical Responses of Polymer Thin Films and Nanocomposites via an Innovative Coarse-grained Approach
Xia, Wenjie; Hsu, David; Keten, Sinan
Understanding and predicting the thermomechanical responses of nanoscale polymer systems are very challenging as their responses are greatly influenced by many factors, such as interfacial energy, filler volume fraction and molecule weight, giving rise to the presence of nanoscale interface and free surface. To overcome these issues, here we employ a novel atomistically informed coarse-grained computational technique, called thermomechanically consistent coarse graining (TCCG), to investigate how the nanoscale interface and free surface influence the elastic modulus (E) and glass transition temperature (Tg) of polymer films and nanocomposites. By performing tensile tests and nanoindentation simulations, we are able to predict the size dependent elastic properties of polymer films and quantify the length scale of the local mechanical interphase. Finally, taking cellulose nanocrystal (CNC) and poly(methyl-methacrylate) (PMMA) nanocomposites as a relevant model system, we present a multi-scale framework built upon our CG approach to allow the prediction of Tg of nanocomposite as a function of interfacial energy and filler volume fractions by drawing the analogy between thin film and nanocomposites. Our established multi-scale framework is validated by recent experiments and breaks new ground in predicting, without any empirical parameters, key structure-property relationships for polymer nanomaterials.
1. Predicting RNA 3D structure using a coarse-grain helix-centered model.
PubMed
Kerpedjiev, Peter; Höner Zu Siederdissen, Christian; Hofacker, Ivo L
2015-06-01
A 3D model of RNA structure can provide information about its function and regulation that is not possible with just the sequence or secondary structure. Current models suffer from low accuracy and long running times and either neglect or presume knowledge of the long-range interactions which stabilize the tertiary structure. Our coarse-grained, helix-based, tertiary structure model operates with only a few degrees of freedom compared with all-atom models while preserving the ability to sample tertiary structures given a secondary structure. It strikes a balance between the precision of an all-atom tertiary structure model and the simplicity and effectiveness of a secondary structure representation. It provides a simplified tool for exploring global arrangements of helices and loops within RNA structures. We provide an example of a novel energy function relying only on the positions of stems and loops. We show that coupling our model to this energy function produces predictions as good as or better than the current state of the art tools. We propose that given the wide range of conformational space that needs to be explored, a coarse-grain approach can explore more conformations in less iterations than an all-atom model coupled to a fine-grain energy function. Finally, we emphasize the overarching theme of providing an ensemble of predicted structures, something which our tool excels at, rather than providing a handful of the lowest energy structures. PMID:25904133
2. Topological defects around a spherical nanoparticle in nematic liquid crystal: coarse-grained molecular dynamics simulations.
PubMed
Ilnytskyi, Jaroslav M; Trokhymchuk, Andrij; Schoen, Martin
2014-09-21
We consider the applicability of coarse-grained molecular dynamics for the simulation of defects in a nematic liquid crystal around a colloidal particle. Two types of colloids are considered, a soft colloid resembling a liquid crystal dendrimer or a similar macromolecule. In addition, a decorated colloid is used which could represent a gold nanoparticle with mesogen-modified surface. For both models we consider homeotropic and tangential anchoring. Precise control of the easy axis on the colloid's surface enables us to focus on specific planar arrangements in the case of a decorated colloid. The nematic phase is modelled explicitly via soft spherocylinders interacting through a potential, suggested by Lintuvuori and Wilson [J. Chem. Phys. 128, 044906 (2008)]. Properties of the nematic phase are studied by computing the Frank elastic constants. In addition, estimates for the nematic-isotropic transition and the coherence length allow us to establish a relation between energy and length scales with respect to experimental systems. Both models exhibit similar defect topologies, namely, that of a Saturn ring and a boojum-type of defect for homeotropic and tangential surface anchoring, respectively. In the decorated colloid model we tune the anchoring strength through the density of the mesogenic shell on the surface. We also found the biaxial boojum defect for the special case of longitudinal planar anchoring. The study demonstrates the potential of coarse-grained simulation methods for studying defects in liquid crystals. PMID:25240368
3. Coarse Grained Approach to First Principles Modeling of Radiation Cascade in Large Fe Supercells
Odbadrakh, Kh; Nicholson, D. M.; Rusanu, A.; Samolyuk, G. D.; Stoller, R. E.; Zhang, X.-G.; Stocks, G. M.
2012-12-01
Classical Molecular Dynamics (MD) simulations characterizing dislocations and radiation damage typically treat 105-107 atoms. First principles techniques employed to understand systems at an atomistic level are not practical for such large systems consisting of millions of atoms. We present an efficient coarse grained (CG) approach to calculate local electronic and magnetic properties of large MD-generated structures from the first principles. Local atomic magnetic moments in crystalline Fe are perturbed by the presence of radiation generated vacancies and interstitials. The effects are most pronounced near the defect cores and decay slowly as the strain field of the defects decrease with distance. We develop the CG technique based on the Locally Self-consistent Multiple Scattering (LSMS) method that exploits the near-sightedness of the electron Green function. The atomic positions were determined by MD with an embedded atom force field. The local moments in the neighborhood of the defect cores are calculated with first-principles based on full local structure information. Atoms in the rest of the system are modeled by representative atoms with approximated properties. The calculations result in local moments near the defect centers with first-principles accuracy, while capturing coarse-grained details of local moments at greater length scales. This CG approach makes these large scale structures amenable to first principles study.
4. Predicting RNA 3D structure using a coarse-grain helix-centered model.
PubMed
Kerpedjiev, Peter; Höner Zu Siederdissen, Christian; Hofacker, Ivo L
2015-06-01
A 3D model of RNA structure can provide information about its function and regulation that is not possible with just the sequence or secondary structure. Current models suffer from low accuracy and long running times and either neglect or presume knowledge of the long-range interactions which stabilize the tertiary structure. Our coarse-grained, helix-based, tertiary structure model operates with only a few degrees of freedom compared with all-atom models while preserving the ability to sample tertiary structures given a secondary structure. It strikes a balance between the precision of an all-atom tertiary structure model and the simplicity and effectiveness of a secondary structure representation. It provides a simplified tool for exploring global arrangements of helices and loops within RNA structures. We provide an example of a novel energy function relying only on the positions of stems and loops. We show that coupling our model to this energy function produces predictions as good as or better than the current state of the art tools. We propose that given the wide range of conformational space that needs to be explored, a coarse-grain approach can explore more conformations in less iterations than an all-atom model coupled to a fine-grain energy function. Finally, we emphasize the overarching theme of providing an ensemble of predicted structures, something which our tool excels at, rather than providing a handful of the lowest energy structures.
5. Molecular dynamics simulation of water in and around carbon nanotubes: A coarse-grained description
Pantawane, Sanwardhini; Choudhury, Niharendu
2016-05-01
In the present study, we intend to investigate behaviour of water in and around hydrophobic open ended carbon nanotubes (CNTs) using a coarse-grained, core-softened model potential for water. The model potential considered here for water has recently been shown to successfully reproduce dynamic, thermodynamic and structural anomalies of water. The epitome of the study is to understand the incarceration of this coarse-grained water in a single-file carbon nanotube. In order to examine the effect of fluid-water van der Waals interaction on the structure of fluid in and around the nanotube, we have simulated three different CNT-water systems with varying degree of solute-water dispersion interaction. The analyses of the radial one-particle density profiles reveal varying degree of permeation and wetting of the CNT interior depending on the degree of fluid-solute attractive van der Waals interaction. A peak in the radial density profile slightly off the nanotube axis signifies a zigzag chain of water molecule around the CNT axis. The average numbers of water molecules inside the CNT have been shown to increase with the increase in fluid-water attractive dispersion interaction.
6. Holliday Junction Thermodynamics and Structure: Coarse-Grained Simulations and Experiments
Wang, Wujie; Nocka, Laura M.; Wiemann, Brianne Z.; Hinckley, Daniel M.; Mukerji, Ishita; Starr, Francis W.
2016-03-01
Holliday junctions play a central role in genetic recombination, DNA repair and other cellular processes. We combine simulations and experiments to evaluate the ability of the 3SPN.2 model, a coarse-grained representation designed to mimic B-DNA, to predict the properties of DNA Holliday junctions. The model reproduces many experimentally determined aspects of junction structure and stability, including the temperature dependence of melting on salt concentration, the bias between open and stacked conformations, the relative populations of conformers at high salt concentration, and the inter-duplex angle (IDA) between arms. We also obtain a close correspondence between the junction structure evaluated by all-atom and coarse-grained simulations. We predict that, for salt concentrations at physiological and higher levels, the populations of the stacked conformers are independent of salt concentration, and directly observe proposed tetrahedral intermediate sub-states implicated in conformational transitions. Our findings demonstrate that the 3SPN.2 model captures junction properties that are inaccessible to all-atom studies, opening the possibility to simulate complex aspects of junction behavior.
7. Coarse-grained electrostatic interactions of coronene: Towards the crystalline phase
SciTech Connect
Heinemann, Thomas Klapp, Sabine H. L.; Palczynski, Karol Dzubiella, Joachim
2015-11-07
In this article, we present and compare two different, coarse-grained approaches to model electrostatic interactions of disc-shaped aromatic molecules, specifically coronene. Our study builds on our previous work [T. Heinemann et al., J. Chem. Phys. 141, 214110 (2014)], where we proposed, based on a systematic coarse-graining procedure starting from the atomistic level, an anisotropic effective (Gay-Berne-like) potential capable of describing van der Waals contributions to the interaction energy. To take into account electrostatics, we introduce, first, a linear quadrupole moment along the symmetry axis of the coronene disc. The second approach takes into account the fact that the partial charges within the molecules are distributed in a ring-like fashion. We then reparametrize the effective Gay-Berne-like potential such that it matches, at short distances, the ring-ring potential. To investigate the validity of these two approaches, we perform many-particle molecular dynamics simulations, focusing on the crystalline phase (karpatite) where electrostatic interaction effects are expected to be particularly relevant for the formation of tilted stacked columns. Specifically, we investigate various structural parameters as well as the melting transition. We find that the second approach yields consistent results with those from experiments despite the fact that the underlying potential decays with the wrong distance dependence at large molecule separations. Our strategy can be transferred to a broader class of molecules, such as benzene or hexabenzocoronene.
8. Using phase information to enhance speckle noise reduction in the ultrasonic NDE of coarse grain materials
SciTech Connect
Lardner, Timothy; Gachagan, Anthony; Li, Minghui
2014-02-18
Materials with a coarse grain structure are becoming increasingly prevalent in industry due to their resilience to stress and corrosion. These materials are difficult to inspect with ultrasound because reflections from the grains lead to high noise levels which hinder the echoes of interest. Spatially Averaged Sub-Aperture Correlation Imaging (SASACI) is an advanced array beamforming technique that uses the cross-correlation between images from array sub-apertures to generate an image weighting matrix, in order to reduce noise levels. This paper presents a method inspired by SASACI to further improve imaging using phase information to refine focusing and reduce noise. A-scans from adjacent array elements are cross-correlated using both signal amplitude and phase to refine delay laws and minimize phase aberration. The phase-based and amplitude-based corrected images are used as inputs to a two-dimensional cross-correlation algorithm that will output a weighting matrix that can be applied to any conventional image. This approach was validated experimentally using a 5MHz array a coarse grained Inconel 625 step wedge, and compared to the Total Focusing Method (TFM). Initial results have seen SNR improvements of over 20dB compared to TFM, and a resolution that is much higher.
9. Path statistics, memory, and coarse-graining of continuous-time random walks on networks.
PubMed
Manhart, Michael; Kion-Crosby, Willow; Morozov, Alexandre V
2015-12-01
Continuous-time random walks (CTRWs) on discrete state spaces, ranging from regular lattices to complex networks, are ubiquitous across physics, chemistry, and biology. Models with coarse-grained states (for example, those employed in studies of molecular kinetics) or spatial disorder can give rise to memory and non-exponential distributions of waiting times and first-passage statistics. However, existing methods for analyzing CTRWs on complex energy landscapes do not address these effects. Here we use statistical mechanics of the nonequilibrium path ensemble to characterize first-passage CTRWs on networks with arbitrary connectivity, energy landscape, and waiting time distributions. Our approach can be applied to calculating higher moments (beyond the mean) of path length, time, and action, as well as statistics of any conservative or non-conservative force along a path. For homogeneous networks, we derive exact relations between length and time moments, quantifying the validity of approximating a continuous-time process with its discrete-time projection. For more general models, we obtain recursion relations, reminiscent of transfer matrix and exact enumeration techniques, to efficiently calculate path statistics numerically. We have implemented our algorithm in PathMAN (Path Matrix Algorithm for Networks), a Python script that users can apply to their model of choice. We demonstrate the algorithm on a few representative examples which underscore the importance of non-exponential distributions, memory, and coarse-graining in CTRWs.
10. Dynamic implicit-solvent coarse-grained models of lipid bilayer membranes: fluctuating hydrodynamics thermostat.
PubMed
Wang, Yaohong; Sigurdsson, Jon Karl; Brandt, Erik; Atzberger, Paul J
2013-08-01
We introduce a thermostat based on fluctuating hydrodynamics for dynamic simulations of implicit-solvent coarse-grained models of lipid bilayer membranes. We show our fluctuating hydrodynamics approach captures interesting correlations in the dynamics of lipid bilayer membranes that are missing in simulations performed using standard Langevin dynamics. Our momentum conserving thermostat accounts for solvent-mediated momentum transfer by coupling coarse-grained degrees of freedom to stochastic continuum fields that account for both the solvent hydrodynamics and thermal fluctuations. We present both a general framework and specific methods to couple the particle and continuum degrees of freedom in a manner consistent with statistical mechanics and amenable to efficient computational simulation. For self-assembled vesicles, we study the diffusivity of lipids and their spatial correlations. We find the hydrodynamic coupling yields within the bilayer interesting correlations between diffusing lipids that manifest as a vortex-like structure similar to those observed in explicit-solvent simulations. We expect the introduced fluctuating hydrodynamics methods to provide a way to extend implicit-solvent models for use in a wide variety of dynamic studies.
11. On the representability problem and the physical meaning of coarse-grained models
Wagner, Jacob W.; Dama, James F.; Durumeric, Aleksander E. P.; Voth, Gregory A.
2016-07-01
In coarse-grained (CG) models where certain fine-grained (FG, i.e., atomistic resolution) observables are not directly represented, one can nonetheless identify indirect the CG observables that capture the FG observable's dependence on CG coordinates. Often, in these cases it appears that a CG observable can be defined by analogy to an all-atom or FG observable, but the similarity is misleading and significantly undermines the interpretation of both bottom-up and top-down CG models. Such problems emerge especially clearly in the framework of the systematic bottom-up CG modeling, where a direct and transparent correspondence between FG and CG variables establishes precise conditions for consistency between CG observables and underlying FG models. Here we present and investigate these representability challenges and illustrate them via the bottom-up conceptual framework for several simple analytically tractable polymer models. The examples provide special focus on the observables of configurational internal energy, entropy, and pressure, which have been at the root of controversy in the CG literature, as well as discuss observables that would seem to be entirely missing in the CG representation but can nonetheless be correlated with CG behavior. Though we investigate these problems in the framework of systematic coarse-graining, the lessons apply to top-down CG modeling also, with crucial implications for simulation at constant pressure and surface tension and for the interpretations of structural and thermodynamic correlations for comparison to experiment.
12. On the representability problem and the physical meaning of coarse-grained models.
PubMed
Wagner, Jacob W; Dama, James F; Durumeric, Aleksander E P; Voth, Gregory A
2016-07-28
In coarse-grained (CG) models where certain fine-grained (FG, i.e., atomistic resolution) observables are not directly represented, one can nonetheless identify indirect the CG observables that capture the FG observable's dependence on CG coordinates. Often, in these cases it appears that a CG observable can be defined by analogy to an all-atom or FG observable, but the similarity is misleading and significantly undermines the interpretation of both bottom-up and top-down CG models. Such problems emerge especially clearly in the framework of the systematic bottom-up CG modeling, where a direct and transparent correspondence between FG and CG variables establishes precise conditions for consistency between CG observables and underlying FG models. Here we present and investigate these representability challenges and illustrate them via the bottom-up conceptual framework for several simple analytically tractable polymer models. The examples provide special focus on the observables of configurational internal energy, entropy, and pressure, which have been at the root of controversy in the CG literature, as well as discuss observables that would seem to be entirely missing in the CG representation but can nonetheless be correlated with CG behavior. Though we investigate these problems in the framework of systematic coarse-graining, the lessons apply to top-down CG modeling also, with crucial implications for simulation at constant pressure and surface tension and for the interpretations of structural and thermodynamic correlations for comparison to experiment. PMID:27475349
13. Thermal and mechanical properties of thermosetting polymers using coarse-grained simulation
Jang, C.; Abrams, C. F.
2016-07-01
We developed coarse-grained (CG) molecular representations of mixtures of diglycidyl ether of bisphenol-A (DGEBA) and poly(oxypropylene) diamine (POP-DA) for use in CG molecular dynamics (MD) simulations. In the CG representation, DGEBA is comprised of three beads of two types and POP-DA also by three beads of two types. Atomistic MD of liquid systems was performed to derive intra- and inter-bead potentials via Boltzmann inversion. While the bonded potentials, composed of bond stretching and angle bending, were parameterized directly from the distribution functions of all atomistic molecular dynamics trajectories, the non-bonded potentials were derived from the iterative Boltzmann Inversion with a given set of coarse-grained interactions. CG systems correctly reproduced liquid and crosslinked densities. Under uniaxial tension, the Young's modulus of the CG systems was much lower than the experimental value, and we show this arises from the assumed form of the extrapolated regions of the CG potentials. By stiffening these regions, we increased the CG Young's modulus of the crosslinked systems without sacrificing the correct prediction of density. This suggests that transferrable CG potentials can be optimized for use in non-equilibrium MD for property estimation.
14. Coarse-grained ions without charges: Reproducing the solvation structure of NaCl in water using short-ranged potentials
DeMille, Robert C.; Molinero, Valeria
2009-07-01
A coarse-grained model of NaCl in water is presented where the ions are modeled without charge to avoid computationally challenging electrostatics. A monatomic model of water [V. Molinero and E. B. Moore, J. Phys. Chem. B 113, 4008 (2009)] is used as the basis for this coarse-grain approach. The ability of Na+ to disrupt the native tetrahedral arrangement of water molecules, and of Cl- to integrate within this organization, is preserved in this mW-ion model through parametrization focused on water's solvation of these ions. This model successfully reproduces the structural effect of ions on water, referenced to observations from experiments and atomistic molecular dynamics simulations, while using extremely short-ranged potentials. Without Coulomb interactions the model replicates details of the ion-water structure such as distinguishing contact and solvent-separated ion pairs and the free energy barriers between them. The approach of mimicking ionic effects with short-ranged interactions results in performance gains of two orders of magnitude compared to Ewald methods. Explored over a broad range of salt concentration, the model reproduces the solvation structure and trends of diffusion relative to atomistic simulations and experimental results. The functional form of the mW-ion model can be parametrized to represent other electrolytes. With increased computational efficiency and reliable structural fidelity, this model promises to be an asset for accessing significantly longer simulation time scales with an explicit solvent in a coarse-grained system involving, for example, polyelectrolytes such as proteins, nucleic acids, and fuel-cell membranes.
15. Coarse-grained Molecular Simulation Studies of Complexation of Sulfobetaine-Lysine Copolymer and DNA for Gene Delivery
2015-03-01
Gene delivery involves successful transfection of therapeutic DNA by a vector into target cells and protein expression of that genetic material. Viral vectors are effective at gene delivery but elicit harmful immunogenic responses, thus motivating ongoing research on non-viral transfection agents. Cationic polymers are a promising class of non-viral vectors due to their low immugenic responses and low toxicity, and their ability to bind to the polyanionic DNA backbone to form a polycation-DNA complex (polyplex) that is then internalized in the target cell. While past studies have shown many polycations with differing DNA transfection efficacies, there is a need for general design guidelines that can relate the molecular features of the polycation to its DNA transfection efficiency. Using atomistic and coarse-grained molecular dynamics simulations we connect polycation design to polycation-DNA binding and experimentally observed transfection efficiency. Specifically in this presentation we will discuss our recent work looking into the effect of incorporating zwitterions into lysine based polycations on the resulting polyplex structure, shape, surface charge density and stability of DNA-polycation complexes.
16. Molecular dynamics simulations of cholesterol-rich membranes using a coarse-grained force field for cyclic alkanes
MacDermaid, Christopher M.; Kashyap, Hemant K.; DeVane, Russell H.; Shinoda, Wataru; Klauda, Jeffery B.; Klein, Michael L.; Fiorin, Giacomo
2015-12-01
The architecture of a biological membrane hinges upon the fundamental fact that its properties are determined by more than the sum of its individual components. Studies on model membranes have shown the need to characterize in molecular detail how properties such as thickness, fluidity, and macroscopic bending rigidity are regulated by the interactions between individual molecules in a non-trivial fashion. Simulation-based approaches are invaluable to this purpose but are typically limited to short sampling times and model systems that are often smaller than the required properties. To alleviate both limitations, the use of coarse-grained (CG) models is nowadays an established computational strategy. We here present a new CG force field for cholesterol, which was developed by using measured properties of small molecules, and can be used in combination with our previously developed force field for phospholipids. The new model performs with precision comparable to atomistic force fields in predicting the properties of cholesterol-rich phospholipid bilayers, including area per lipid, bilayer thickness, tail order parameter, increase in bending rigidity, and propensity to form liquid-ordered domains in ternary mixtures. We suggest the use of this model to quantify the impact of cholesterol on macroscopic properties and on microscopic phenomena involving localization and trafficking of lipids and proteins on cellular membranes.
17. Molecular dynamics simulations of cholesterol-rich membranes using a coarse-grained force field for cyclic alkanes
SciTech Connect
MacDermaid, Christopher M. Klein, Michael L.; Fiorin, Giacomo; Kashyap, Hemant K.; DeVane, Russell H.; Shinoda, Wataru; Klauda, Jeffery B.
2015-12-28
The architecture of a biological membrane hinges upon the fundamental fact that its properties are determined by more than the sum of its individual components. Studies on model membranes have shown the need to characterize in molecular detail how properties such as thickness, fluidity, and macroscopic bending rigidity are regulated by the interactions between individual molecules in a non-trivial fashion. Simulation-based approaches are invaluable to this purpose but are typically limited to short sampling times and model systems that are often smaller than the required properties. To alleviate both limitations, the use of coarse-grained (CG) models is nowadays an established computational strategy. We here present a new CG force field for cholesterol, which was developed by using measured properties of small molecules, and can be used in combination with our previously developed force field for phospholipids. The new model performs with precision comparable to atomistic force fields in predicting the properties of cholesterol-rich phospholipid bilayers, including area per lipid, bilayer thickness, tail order parameter, increase in bending rigidity, and propensity to form liquid-ordered domains in ternary mixtures. We suggest the use of this model to quantify the impact of cholesterol on macroscopic properties and on microscopic phenomena involving localization and trafficking of lipids and proteins on cellular membranes.
18. Coarse-graining molecular dynamics models using an extended Galerkin method
Li, Xiantao
2013-03-01
I will present a systematic approach to coarse-grain molecular dynamics models for solids. The coarse-grained models are derived by Galerkin projection to a sequence of Krylov subspaces. On the coarsest space, the model corresponds to a finite element discretization of the continuum elasto-dynamics model. On the other hand, the projection to the finest space yields the full molecular dynamics description. The models in between serve as a smooth transition between the two scales. We start with a molecular dynamics (MD) model, mix¨i = -∂V/∂xi . First, let Y0 be the approximation space for the continuum model. By projecting the MD model onto the subspace, we obtain a coarse-grained model, M q ¨ = F (q) . Using the Cauchy-Born approximation, this model can be shown to coincide with the finite element representation of the continuum elastodynamics model. This model has limited accuracy near lattice defects. One natural idea is to switch to the MD model in regions surround local defect. As a result, one creates an interface between the continuum and atomistic description, where coupling conditions are needed. Direct coupling methods may involve enforcing constraints or mixing the energy or forces. Such an approach may suffer from large phonon reflections at the interface, and introduce large modeling error. In order to seamlessly couple this model to MD, we successively expand the approximation space to the Krylov spaces, Kl =Y0 + AY0 + ⋯ +AlY0 . Here A is the force constant matrix, computed from the atomistic model. Due to the translational invariance, only a smaller number of such matrices need to be computed. By projecting the MD model onto this new subspace, we obtain an extended system, M q .. =F0 (q ,ξ1 , ... ,ξl) ,ξ̈1 =F1 (q ,ξ1 , ... ,ξl) , ... ... ,ξ̈l =Fl (q ,ξ1 , ... ,ξl) . The additional variables ξj represent the coefficients in the extended approximation space. Using this systematic approach, one can build a hierarchy of models with
19. The geometry of generalized force matching and related information metrics in coarse-graining of molecular systems.
PubMed
Kalligiannaki, Evangelia; Harmandaris, Vagelis; Katsoulakis, Markos A; Plecháč, Petr
2015-08-28
Using the probabilistic language of conditional expectations, we reformulate the force matching method for coarse-graining of molecular systems as a projection onto spaces of coarse observables. A practical outcome of this probabilistic description is the link of the force matching method with thermodynamic integration. This connection provides a way to systematically construct a local mean force and to optimally approximate the potential of mean force through force matching. We introduce a generalized force matching condition for the local mean force in the sense that allows the approximation of the potential of mean force under both linear and non-linear coarse graining mappings (e.g., reaction coordinates, end-to-end length of chains). Furthermore, we study the equivalence of force matching with relative entropy minimization which we derive for general non-linear coarse graining maps. We present in detail the generalized force matching condition through applications to specific examples in molecular systems.
20. The geometry of generalized force matching and related information metrics in coarse-graining of molecular systems
SciTech Connect
Kalligiannaki, Evangelia; Harmandaris, Vagelis; Plecháč, Petr
2015-08-28
Using the probabilistic language of conditional expectations, we reformulate the force matching method for coarse-graining of molecular systems as a projection onto spaces of coarse observables. A practical outcome of this probabilistic description is the link of the force matching method with thermodynamic integration. This connection provides a way to systematically construct a local mean force and to optimally approximate the potential of mean force through force matching. We introduce a generalized force matching condition for the local mean force in the sense that allows the approximation of the potential of mean force under both linear and non-linear coarse graining mappings (e.g., reaction coordinates, end-to-end length of chains). Furthermore, we study the equivalence of force matching with relative entropy minimization which we derive for general non-linear coarse graining maps. We present in detail the generalized force matching condition through applications to specific examples in molecular systems.
1. A coarse-graining approach for molecular simulation that retains the dynamics of the all-atom reference system by implementing hydrodynamic interactions
SciTech Connect
Markutsya, Sergiy; Lamm, Monica H
2014-11-07
We report on a new approach for deriving coarse-grained intermolecular forces that retains the frictional contribution that is often discarded by conventional coarse-graining methods. The approach is tested for water and an aqueous glucose solution, and the results from the new implementation for coarse-grained molecular dynamics simulation show remarkable agreement with the dynamics obtained from reference all-atom simulations. The agreement between the structural properties observed in the coarse-grained and all-atom simulations is also preserved. We discuss how this approach may be applied broadly to any existing coarse-graining method where the coarse-grained models are rigorously derived from all-atom reference systems.
2. Systematic coarse-graining of spectrin-level red blood cell models
PubMed Central
Fedosov, Dmitry A.; Caswell, Bruce; Karniadakis, George Em
2013-01-01
We present a rigorous procedure to derive coarse-grained red blood cell (RBC) models, which yield accurate mechanical response. Based on a semi-analytic theory the linear and nonlinear elastic properties of healthy and infected RBCs in malaria can be matched with those obtained in optical tweezers stretching experiments. The present analysis predicts correctly the membrane Young’s modulus in contrast to about 50% error in predictions by previous models. In addition, we develop a stress-free model which avoids a number of pitfalls of existing RBC models, such as non-smooth or poorly controlled equilibrium shape and dependence of the mechanical properties on the initial triangulation quality. Here we employ dissipative particle dynamics for the implementation but the proposed model is general and suitable for use in many existing continuum and particle-based numerical methods. PMID:24353352
3. Emergence of attraction in simulations of coarse-grained double stranded DNA
2015-03-01
DNA condensation induced by multivalent counterions is believed to play an important role in DNA bundling and packing into the cell nucleus. We present a coarse-grained, implicit solvent representation of rigid ds-DNA molecules in the presence of divalent counterions. In order to include solvation effects arising from the discrete nature of the water molecules, short-ranged corrections are added to the pairwise interaction potentials such that the structure of counterions is consistent with results from corresponding explicit solvent simulations. The effective force between two DNA strands generated by these potentials provides an excellent match to that observed in the explicit solvent model. Importantly, this interaction features multiple minima and reproduces the like-charge attraction effect between DNA molecules observed in full atomistic simulations at significantly reduced computational expense. This result proves that it is possible to capture complex multibody interactions between polyelectrolyte strands with two-body potentials.
4. Coarse-grained simulations of flow-induced morphology dynamics in dispersed graphene
Xu, Yueyi; Green, Micah
2013-11-01
We investigated how flow fields affect graphene morphology dynamics in liquid phase using a coarse-grained model. Past simulations of the dynamics of dispersed graphene sheets are limited to static fluids on small timescales, with little attention devoted to flow dynamics, which is critical given the importance of graphene solution-processing of multifunctional devices and materials. We developed a Brownian Dynamics (BD) algorithm to study the morphology of sheetlike macromolecules in dilute solutions with an applied external flow field. We used a bead-rod lattice to represent the mesoscopic conformation of individual two dimensional sheets. We then analyzed the morphology dynamic modes (stretching, tumbling, crumpling) of these molecules as a function of sheet size, Weissenberg number, and bending stiffness. The physical properties (e. g. viscosity) affected by the morphology are also studied. Our results demonstrate how bending stiffness relates to relaxation modes during startup of shear.
5. A coarse-grain force field for RDX: Density dependent and energy conserving
Moore, Joshua D.; Barnes, Brian C.; Izvekov, Sergei; Lísal, Martin; Sellers, Michael S.; Taylor, DeCarlos E.; Brennan, John K.
2016-03-01
We describe the development of a density-dependent transferable coarse-grain model of crystalline hexahydro-1,3,5-trinitro-s-triazine (RDX) that can be used with the energy conserving dissipative particle dynamics method. The model is an extension of a recently reported one-site model of RDX that was developed by using a force-matching method. The density-dependent forces in that original model are provided through an interpolation scheme that poorly conserves energy. The development of the new model presented in this work first involved a multi-objective procedure to improve the structural and thermodynamic properties of the previous model, followed by the inclusion of the density dependency via a conservative form of the force field that conserves energy. The new model accurately predicts the density, structure, pressure-volume isotherm, bulk modulus, and elastic constants of the RDX crystal at ambient pressure and exhibits transferability to a liquid phase at melt conditions.
6. Experimental study on waves propagation over a coarse-grained sloping beach
Hsu, Tai-Wen; Lai, Jian-Wu
2013-04-01
This study investigates velocity fields of wave propagation over a coarse-grained sloping beach using laboratory experiments. The experiment was conducted in a wave flume of 25 m long, 0.5 m wide and 0.6 m high in which a coarse-grained sloping 1:5 beach was placed with two layers ball. The glass ball is D=7.9 cm and the center to center distance of each ball is 8.0 cm. The test section for observing wave and flow fields is located at the middle part of the flume. A piston type wave maker driven by an electromechanical hydraulic serve system is installed at the end of the flume. The intrinsic permeability Kp and turbulent drag coefficient Cf were obtained from steady flow water-head experiments. The flow velocity was measured by the particle image velocimeter (PIV) and digital image process (DIP) techniques. Eleven fields of view (FOVS) were integrated into a complete representation including the outer, surf and swash zone. Details of the definition sketch of the coarse-grained sloping beach model as well as experimental setup are referred to Lai et al. (2008). A high resolution of CCD camera was used to capture the images which was calibrated by the direct linear transform (DCT) algorithm proposed by Abed El-Aziz and Kar-Ara (1971). The water surface between the interface of air and water at each time step are calculated by Otsu' (1978) detect algorithm. The comparison shows that the water surface elevation observed by integrated image agrees well with that of Otsu' detection results. For the flow field measurement, each image pair was cross correlated with 32X32 pixel inter rogation window and a half overlap between adjacent windows. The repeatability and synchronization are the key elements for both wave motion and PIV technique. The wave profiles and flow field were compared during several wave periods to ensure that they can be reproduced by the present system. The water depth is kept as a constant of h=32 cm. The incident wave conditions are set to be wave
7. Coarse-graining intermittent intracellular transport: Two- and three-dimensional models.
PubMed
Lawley, Sean D; Tuft, Marie; Brooks, Heather A
2015-10-01
Viruses and other cellular cargo that lack locomotion must rely on diffusion and cellular transport systems to navigate through a biological cell. Indeed, advances in single particle tracking have revealed that viral motion alternates between (a) diffusion in the cytoplasm and (b) active transport along microtubules. This intermittency makes quantitative analysis of trajectories difficult. Therefore, the purpose of this paper is to construct mathematical methods to approximate intermittent dynamics by effective stochastic differential equations. The coarse-graining method that we develop is more accurate than existing techniques and applicable to a wide range of intermittent transport models. In particular, we apply our method to two- and three-dimensional cell geometries (disk, sphere, and cylinder) and demonstrate its accuracy. In addition to these specific applications, we also explain our method in full generality for use on future intermittent models.
8. Development of DPD coarse-grained models: From bulk to interfacial properties.
PubMed
Solano Canchaya, José G; Dequidt, Alain; Goujon, Florent; Malfreyt, Patrice
2016-08-01
A new Bayesian method was recently introduced for developing coarse-grain (CG) force fields for molecular dynamics. The CG models designed for dissipative particle dynamics (DPD) are optimized based on trajectory matching. Here we extend this method to improve transferability across thermodynamic conditions. We demonstrate the capability of the method by developing a CG model of n-pentane from constant-NPT atomistic simulations of bulk liquid phases and we apply the CG-DPD model to the calculation of the surface tension of the liquid-vapor interface over a large range of temperatures. The coexisting densities, vapor pressures, and surface tensions calculated with different CG and atomistic models are compared to experiments. Depending on the database used for the development of the potentials, it is possible to build a CG model which performs very well in the reproduction of the surface tension on the orthobaric curve. PMID:27497539
9. Generalization of the DLA process with different immiscible components by time-scale coarse graining
Postnikov, E. B.; Ryabov, A. B.; Loskutov, A.
2007-10-01
In the framework of the mean-field approximation we propose a new approach to the description of the growth of fractal structures which are formed as a result of the process of diffusion limited aggregation. Our approach is based on the coarse graining of the time scale which takes into account the property of discreteness of such structures. The obtained system of partial differential equations allows us to evaluate numerically the fractal dimension and the cluster density depending on the distance from the cluster center. The results are in a quite good agreement with values found by the direct numerical simulations. The proposed approach is generalized for the case of the cluster description with different immiscible particles.
10. Monte-Carlo simulations of a coarse-grained model for α-oligothiophenes
Almutairi, Amani; Luettmer-Strathmann, Jutta
The interfacial layer of an organic semiconductor in contact with a metal electrode has important effects on the performance of thin-film devices. However, the structure of this layer is not easy to model. Oligothiophenes are small, π-conjugated molecules with applications in organic electronics that also serve as small-molecule models for polythiophenes. α-hexithiophene (6T) is a six-ring molecule, whose adsorption on noble metal surfaces has been studied extensively (see, e.g., Ref.). In this work, we develop a coarse-grained model for α-oligothiophenes. We describe the molecules as linear chains of bonded, discotic particles with Gay-Berne potential interactions between non-bonded ellipsoids. We perform Monte Carlo simulations to study the structure of isolated and adsorbed molecules
11. Highly Scalable and Memory Efficient Ultra-Coarse-Grained Molecular Dynamics Simulations.
PubMed
Grime, John M A; Voth, Gregory A
2014-01-14
The use of coarse-grained (CG) models can significantly increase the time and length scales accessible to computational molecular dynamics (MD) simulations. To address very large-scale phenomena, however, requires a careful consideration of memory requirements and parallel MD load balancing in order to make efficient use of current supercomputers. In this work, a CG-MD code is introduced which is specifically designed for very large, highly parallel simulations of systems with markedly non-uniform particle distributions, such as those found in highly CG models having an implicit solvent. The CG-MD code uses an unorthodox combination of sparse data representations with a Hilbert space-filling curve (SFC) to provide dynamic topological descriptions, reduced memory overhead, and advanced load-balancing characteristics. The results of representative large-scale simulations indicate that our approach can offer significant advantages over conventional MD techniques, and should enable new classes of CG-MD systems to be investigated. PMID:26579921
12. Virtual ultrasound sources for inspecting nuclear components of coarse-grained structure
SciTech Connect
Brizuela, J.; Katchadjian, P.; Desimone, C.; Garcia, A.
2014-02-18
This work describes an ultrasonic inspection procedure designed for verifying coarse-grained structure materials, which are commonly used on nuclear reactors. In this case, conventional phased array techniques cannot be used due to attenuating characteristics and backscattered noise from microstructures inside the material. Thus, synthetic aperture ultrasonic imaging (SAFT) is used for this approach in contact conditions. In order to increase energy transferred to the medium, synthetic transmit aperture is formed by several elements which generate a diverging wavefront equivalent to a virtual ultrasound source behind the transducer. On the other hand, the phase coherence technique has been applied to reduce more structural noise and improve the image quality. The beamforming process has been implemented over a GPU platform to reduce computing time.
13. Tension-compression-tension tertiary twins in coarse-grained polycrystalline pure magnesium at room temperature
DOE PAGESBeta
Yu, Qin; Jiang, Yanyao; Wang, Jian
2015-04-07
Using electron backscatter diffraction, the microstructural features of tension–compression–tension (T–C–T) tertiary twins are studied in coarse-grained pure polycrystalline magnesium subjected to monotonic compression along the extrusion direction in ambient air. T–C–T tertiary twins are developed due to the formation of a compression–tension double twin inside a primary tension twin. All the observed T–C–T twin variants are of TiCjTj type. TiCi+1Ti+1 (or TiCi–1Ti–1) variants are observed more frequently than TiCi+2Ti+2 (or TiCi–2Ti–2) variants. Moreover, the number of tertiary twin lamellae increases with the applied compressive strain.
14. Coarse-graining intermittent intracellular transport: Two- and three-dimensional models
Lawley, Sean D.; Tuft, Marie; Brooks, Heather A.
2015-10-01
Viruses and other cellular cargo that lack locomotion must rely on diffusion and cellular transport systems to navigate through a biological cell. Indeed, advances in single particle tracking have revealed that viral motion alternates between (a) diffusion in the cytoplasm and (b) active transport along microtubules. This intermittency makes quantitative analysis of trajectories difficult. Therefore, the purpose of this paper is to construct mathematical methods to approximate intermittent dynamics by effective stochastic differential equations. The coarse-graining method that we develop is more accurate than existing techniques and applicable to a wide range of intermittent transport models. In particular, we apply our method to two- and three-dimensional cell geometries (disk, sphere, and cylinder) and demonstrate its accuracy. In addition to these specific applications, we also explain our method in full generality for use on future intermittent models.
15. Investigating bile salt aggregation using coarse-grained molecular dynamics simulations
Vila Verde, Ana; Frenkel, Daan
2010-03-01
Bile salts are necessary for fat digestion due to their unusual surfactant properties: they assemble into small, polydisperse micelles and easily form mixed micelles with poorly soluble amphiphiles. Understanding these properties requires molecular scale information about bile salt micelles, something challenging to obtain experimentally but amenable to computational modeling. To address this issue we build a coarse-grained model of bile salts. We investigate their aggregation behavior through molecular dynamics simulations in a grand-canonical parallel tempering scheme. We validate our model against available solubility and light scattering data. Our results indicate that at physiological bile salt and counter ion concentrations, bile salts pack in many different orientations in pure bile micelles, contrary to standard surfactants. This feature may be physiologically relevant, allowing bile salts to solubilize the heterogeneous blends of fats typical of digestion.
16. Development of DPD coarse-grained models: From bulk to interfacial properties
Solano Canchaya, José G.; Dequidt, Alain; Goujon, Florent; Malfreyt, Patrice
2016-08-01
A new Bayesian method was recently introduced for developing coarse-grain (CG) force fields for molecular dynamics. The CG models designed for dissipative particle dynamics (DPD) are optimized based on trajectory matching. Here we extend this method to improve transferability across thermodynamic conditions. We demonstrate the capability of the method by developing a CG model of n-pentane from constant-NPT atomistic simulations of bulk liquid phases and we apply the CG-DPD model to the calculation of the surface tension of the liquid-vapor interface over a large range of temperatures. The coexisting densities, vapor pressures, and surface tensions calculated with different CG and atomistic models are compared to experiments. Depending on the database used for the development of the potentials, it is possible to build a CG model which performs very well in the reproduction of the surface tension on the orthobaric curve.
17. Highly Scalable and Memory Efficient Ultra-Coarse-Grained Molecular Dynamics Simulations.
PubMed
Grime, John M A; Voth, Gregory A
2014-01-14
The use of coarse-grained (CG) models can significantly increase the time and length scales accessible to computational molecular dynamics (MD) simulations. To address very large-scale phenomena, however, requires a careful consideration of memory requirements and parallel MD load balancing in order to make efficient use of current supercomputers. In this work, a CG-MD code is introduced which is specifically designed for very large, highly parallel simulations of systems with markedly non-uniform particle distributions, such as those found in highly CG models having an implicit solvent. The CG-MD code uses an unorthodox combination of sparse data representations with a Hilbert space-filling curve (SFC) to provide dynamic topological descriptions, reduced memory overhead, and advanced load-balancing characteristics. The results of representative large-scale simulations indicate that our approach can offer significant advantages over conventional MD techniques, and should enable new classes of CG-MD systems to be investigated.
18. Effective thermostat induced by coarse graining of simple point charge water.
PubMed
Eriksson, Anders; Jacobi, Martin Nilsson; Nyström, Johan; Tunstrøm, Kolbjørn
2008-07-14
We investigate how the transport properties of a united atom fluid with a dissipative particle dynamics thermostat depend on the functional form and magnitude of both the conservative and the stochastic interactions. We demonstrate how the thermostat strongly affects the hydrodynamics, especially diffusion, viscosity, and local escape times. As model system we use simple point charge (SPC) water, from which projected trajectories are used to determine the effective interactions in the united atom model. The simulation results support our argument that the thermostat should be viewed as an integral part of the coarse-grained dynamics rather than a tool for approaching thermal equilibrium. As our main result we show that the united atom model with the adjusted effective interactions approximately reproduces the diffusion constant and the viscosity of the underlying detailed SPC water model.
19. A temperature-dependent coarse-grained model for the thermoresponsive polymer poly(N-isopropylacrylamide)
DOE PAGESBeta
Abbott, Lauren J.; Stevens, Mark J.
2015-12-22
In this study, a coarse-grained (CG) model is developed for the thermoresponsive polymer poly(N-isopropylacrylamide) (PNIPAM), using a hybrid top-down and bottom-up approach. Nonbonded parameters are fit to experimental thermodynamic data following the procedures of the SDK (Shinoda, DeVane, and Klein) CG force field, with minor adjustments to provide better agreement with radial distribution functions from atomistic simulations. Bonded parameters are fit to probability distributions from atomistic simulations using multi-centered Gaussian-based potentials. The temperature-dependent potentials derived for the PNIPAM CG model in this work properly capture the coil–globule transition of PNIPAM single chains and yield a chain-length dependence consistent with atomisticmore » simulations.« less
20. A temperature-dependent coarse-grained model for the thermoresponsive polymer poly(N-isopropylacrylamide)
SciTech Connect
Abbott, Lauren J.; Stevens, Mark J.
2015-12-28
A coarse-grained (CG) model is developed for the thermoresponsive polymer poly(N-isopropylacrylamide) (PNIPAM), using a hybrid top-down and bottom-up approach. Nonbonded parameters are fit to experimental thermodynamic data following the procedures of the SDK (Shinoda, DeVane, and Klein) CG force field, with minor adjustments to provide better agreement with radial distribution functions from atomistic simulations. Bonded parameters are fit to probability distributions from atomistic simulations using multi-centered Gaussian-based potentials. The temperature-dependent potentials derived for the PNIPAM CG model in this work properly capture the coil–globule transition of PNIPAM single chains and yield a chain-length dependence consistent with atomistic simulations.
1. A temperature-dependent coarse-grained model for the thermoresponsive polymer poly(N-isopropylacrylamide)
SciTech Connect
Abbott, Lauren J.; Stevens, Mark J.
2015-12-22
In this study, a coarse-grained (CG) model is developed for the thermoresponsive polymer poly(N-isopropylacrylamide) (PNIPAM), using a hybrid top-down and bottom-up approach. Nonbonded parameters are fit to experimental thermodynamic data following the procedures of the SDK (Shinoda, DeVane, and Klein) CG force field, with minor adjustments to provide better agreement with radial distribution functions from atomistic simulations. Bonded parameters are fit to probability distributions from atomistic simulations using multi-centered Gaussian-based potentials. The temperature-dependent potentials derived for the PNIPAM CG model in this work properly capture the coil–globule transition of PNIPAM single chains and yield a chain-length dependence consistent with atomistic simulations.
2. Coarse-grained depletion potentials for anisotropic colloids: Application to lock-and-key systems.
PubMed
Law, Clement; Ashton, Douglas J; Wilding, Nigel B; Jack, Robert L
2016-08-28
When colloids are mixed with a depletant such as a non-adsorbing polymer, one observes attractive effective interactions between the colloidal particles. If these particles are anisotropic, analysis of these effective interactions is challenging in general. We present a method for inference of approximate (coarse-grained) effective interaction potentials between such anisotropic particles. Using the example of indented (lock-and-key) colloids, we show how numerical solutions can be used to integrate out the (hard sphere) depletant, leading to a depletion potential that accurately characterises the effective interactions. The accuracy of the method is based on matching of contributions to the second virial coefficient of the colloids. The simplest version of our method yields a piecewise-constant effective potential; we also show how this scheme can be generalised to other functional forms, where appropriate. PMID:27586946
3. Ultrasonic Sound Field Mapping Through Coarse Grained Cast Austenitic Stainless Steel Components
SciTech Connect
Crawford, Susan L.; Prowant, Matthew S.; Cinson, Anthony D.; Larche, Michael R.; Diaz, Aaron A.
2014-08-01
The Pacific Northwest National Laboratory (PNNL) has been involved with nondestructive examination (NDE) of coarse-grained cast austenitic stainless steel (CASS) components for over 30 years. More recent work has focused on mapping the ultrasonic sound fields generated by low-frequency phased array probes that are typically used for the evaluation of CASS materials for flaw detection and characterization. The casting process results in the formation of large grained material microstructures that are nonhomogeneous and anisotropic. The propagation of ultrasonic energy for examination of these materials results in scattering, partitioning and redirection of these sound fields. The work reported here provides an assessment of sound field formation in these materials and provides recommendations on ultrasonic inspection parameters for flaw detection in CASS components.
4. A connection rule for alpha-carbon coarse-grained elastic network models using chemical bond information.
PubMed
Jeong, Jay I; Jang, Yunho; Kim, Moon K
2006-01-01
A sparser but more efficient connection rule (called a bond-cutoff method) for a simplified alpha-carbon coarse-grained elastic network model is presented. One of conventional connection rules for elastic network models is the distance-cutoff method, where virtual springs connect an alpha-carbon with all neighbor alpha-carbons within predefined distance-cutoff value. However, though the maximum interaction distance between alpha-carbons is reported as 7 angstroms, this cutoff value can make the elastic network unstable in many cases of protein structures. Thus, a larger cutoff value (>11 angstroms) is often used to establish a stable elastic network model in previous researches. To overcome this problem, a connection rule for backbone model is proposed, which satisfies the minimum condition to stabilize an elastic network. Based on the backbone connections, each type of chemical interactions is considered and added to the elastic network model: disulfide bonds, hydrogen bonds, and salt-bridges. In addition, the van der Waals forces between alpha-carbons are modeled by using the distance-cutoff method. With the proposed connection rule, one can make an elastic network model with less than 7 angstroms distance cutoff, which can reveal protein flexibility more sharply. Moreover, the normal modes from the new elastic network model can reflect conformational changes of a given protein better than ones by the distance-cutoff method. This method can save the computational cost when calculating normal modes of a given protein structure, because it can reduce the total number of connections. As a validation, six example proteins are tested. Computational times and the overlap values between the conformational change and infinitesimal motion calculated by normal mode analysis are presented. Those animations are also available at UMass Morph Server (http://biomechanics.ecs.umass.edu/umms.html).
5. A Coarse-Grained Model of Stratum Corneum Lipids: Free Fatty Acids and Ceramide NS.
PubMed
Moore, Timothy C; Iacovella, Christopher R; Hartkamp, Remco; Bunge, Annette L; McCabe, Clare
2016-09-22
Ceramide (CER)-based biological membranes are used both experimentally and in simulations as simplified model systems of the skin barrier. Molecular dynamics studies have generally focused on simulating preassembled structures using atomistically detailed models of CERs, which limit the system sizes and time scales that can practically be probed, rendering them ineffective for studying particular phenomena, including self-assembly into bilayer and lamellar superstructures. Here, we report on the development of a coarse-grained (CG) model for CER NS, the most abundant CER in human stratum corneum. Multistate iterative Boltzmann inversion is used to derive the intermolecular pair potentials, resulting in a force field that is applicable over a range of state points and suitable for studying ceramide self-assembly. The chosen CG mapping, which includes explicit interaction sites for hydroxyl groups, captures the directional nature of hydrogen bonding and allows for accurate predictions of several key structural properties of CER NS bilayers. Simulated wetting experiments allow the hydrophobicity of CG beads to be accurately tuned to match atomistic wetting behavior, which affects the whole system, since inaccurate hydrophobic character is found to unphysically alter the lipid packing in hydrated lamellar states. We find that CER NS can self-assemble into multilamellar structures, enabling the study of lipid systems more representative of the multilamellar lipid structures present in the skin barrier. The coarse-grained force field derived herein represents an important step in using molecular dynamics to study the human skin barrier, which gives a resolution not available through experiment alone. PMID:27564869
6. Deviation of permeable coarse-grained boundary resistance from Nikuradse's observations
Cheng, Nian-Sheng; Liu, Xingnian; Chen, Xingwei; Qiao, Changkai
2016-02-01
Nikuradse's (1933) rough pipe study is enormously influential in the understanding of flow resistance over a sediment bed. However, the rough boundary employed in Nikuradse's study differs from permeable sediment beds in rivers. This implies that the results derived from the rough pipe experiments may not be applicable for flows over a permeable coarse-grained bed. The present study aimed to explore to what extent the flow resistance of a permeable coarse-grained boundary deviates from the Nikuradse's observations. Experiments were conducted with rough pipes, which were prepared by overlaying the inner wall with one to four layers of spherical beads. The single layer roughness resembles the experimental setup reported in Nikuradse's study, while the multilayer of grains allows significant flow to pass through the porous roughness layer. In addition, the ratio of grain diameter, k, to pipe diameter, d, was chosen to be one to two orders greater than the range (0.001 < k/d < 0.033) adopted in Nikuradse's experiments. The data show that the friction factor deviates significantly from the prediction based on Nikuradse's rough pipe relation. For hydraulically rough pipes, the friction factor is found to be proportional to the squared ratio of the grain diameter to nominal pipe diameter. This result is different from the one-third power function as implied by Nikuradse's rough pipe relation or the Manning-Strickler formula but agrees well with laboratory observations of open channel resistance in the presence of large-scale roughness. The measurements also suggest the existence of a laminar flow regime, in which the friction factor is inversely proportional to the Reynolds number. The observed variations in the flow resistance are attributed to both wall permeability and large-scale roughness.
7. Coarse-Grained Molecular Dynamics Simulations of Membrane-Trehalose Interactions.
PubMed
Kapla, Jon; Stevensson, Baltzar; Maliniak, Arnold
2016-09-15
It is well established that trehalose (TRH) affects the physical properties of lipid bilayers and stabilizes biological membranes. We present molecular dynamics (MD) computer simulations to investigate the interactions between lipid membranes formed by 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and TRH. Both atomistic and coarse-grained (CG) interaction models were employed, and the coarse graining of DMPC leads to a reduction in the acyl chain length corresponding to a 1,2-dilauroyl-sn-glycero-3-phosphocholine lipid (DLPC). Several modifications of the Martini interaction model, used for CG simulations, were implemented, resulting in different potentials of mean force (PMFs) for DMPC bilayer-TRH interactions. These PMFs were subsequently used in a simple two-site analytical model for the description of sugar binding at the membrane interface. In contrast to that in atomistic MD simulations, the binding in the CG model was not in agreement with the two-site model. Our interpretation is that the interaction balance, involving water, TRH, and lipids, in the CG systems needs further tuning of the force-field parameters. The area per lipid is only weakly affected by TRH concentration, whereas the compressibility modulus related to the fluctuations of the membrane increases with an increase in TRH content. In agreement with experimental findings, the bending modulus is not affected by the inclusion of TRH. The important aspects of lipid bilayer interactions with biomolecules are membrane curvature generation and sensing. In the present investigation, membrane curvature is generated by artificial buckling of the bilayer in one dimension. It turns out that TRH prefers the regions with the highest curvature, which enables the most favorable situation for lipid-sugar interactions. PMID:27530142
8. Polarizable Water Model for the Coarse-Grained MARTINI Force Field
PubMed Central
Sengupta, Durba; Marrink, Siewert J.
2010-01-01
Coarse-grained (CG) simulations have become an essential tool to study a large variety of biomolecular processes, exploring temporal and spatial scales inaccessible to traditional models of atomistic resolution. One of the major simplifications of CG models is the representation of the solvent, which is either implicit or modeled explicitly as a van der Waals particle. The effect of polarization, and thus a proper screening of interactions depending on the local environment, is absent. Given the important role of water as a ubiquitous solvent in biological systems, its treatment is crucial to the properties derived from simulation studies. Here, we parameterize a polarizable coarse-grained water model to be used in combination with the CG MARTINI force field. Using a three-bead model to represent four water molecules, we show that the orientational polarizability of real water can be effectively accounted for. This has the consequence that the dielectric screening of bulk water is reproduced. At the same time, we parameterized our new water model such that bulk water density and oil/water partitioning data remain at the same level of accuracy as for the standard MARTINI force field. We apply the new model to two cases for which current CG force fields are inadequate. First, we address the transport of ions across a lipid membrane. The computed potential of mean force shows that the ions now naturally feel the change in dielectric medium when moving from the high dielectric aqueous phase toward the low dielectric membrane interior. In the second application we consider the electroporation process of both an oil slab and a lipid bilayer. The electrostatic field drives the formation of water filled pores in both cases, following a similar mechanism as seen with atomistically detailed models. PMID:20548957
9. PRAM C:a new programming environment for fine-grain and coarse-grain parallelism.
SciTech Connect
Brown, Jonathan Leighton; Wen, Zhaofang.
2004-11-01
In the search for ''good'' parallel programming environments for Sandia's current and future parallel architectures, they revisit a long-standing open question. Can the PRAM parallel algorithms designed by theoretical computer scientists over the last two decades be implemented efficiently? This open question has co-existed with ongoing efforts in the HPC community to develop practical parallel programming models that can simultaneously provide ease of use, expressiveness, performance, and scalability. Unfortunately, no single model has met all these competing requirements. Here they propose a parallel programming environment, PRAM C, to bridge the gap between theory and practice. This is an attempt to provide an affirmative answer to the PRAM question, and to satisfy these competing practical requirements. This environment consists of a new thin runtime layer and an ANSI C extension. The C extension has two control constructs and one additional data type concept, ''shared''. This C extension should enable easy translation from PRAM algorithms to real parallel programs, much like the translation from sequential algorithms to C programs. The thin runtime layer bundles fine-grained communication requests into coarse-grained communication to be served by message-passing. Although the PRAM represents SIMD-style fine-grained parallelism, a stand-alone PRAM C environment can support both fine-grained and coarse-grained parallel programming in either a MIMD or SPMD style, interoperate with existing MPI libraries, and use existing hardware. The PRAM C model can also be integrated easily with existing models. Unlike related efforts proposing innovative hardware with the goal to realize the PRAM, ours can be a pure software solution with the purpose to provide a practical programming environment for existing parallel machines; it also has the potential to perform well on future parallel architectures.
10. Coarse-grained Brownian ratchet model of membrane protrusion on cellular scale.
PubMed
2011-07-01
Membrane protrusion is a mechanochemical process of active membrane deformation driven by actin polymerization. Previously, Brownian ratchet (BR) was modeled on the basis of the underlying molecular mechanism. However, because the BR requires a priori load that cannot be determined without information of the cell shape, it cannot be effective in studies in which resultant shapes are to be solved. Other cellular-scale models describing the protrusion have also been suggested for modeling a whole cell; however, these models were not developed on the basis of coarse-grained physics representing the underlying molecular mechanism. Therefore, to express the membrane protrusion on the cellular scale, we propose a novel mathematical model, the coarse-grained BR (CBR), which is derived on the basis of nonequilibrium thermodynamics theory. The CBR can reproduce the BR within the limit of the quasistatic process of membrane protrusion and can estimate the protrusion velocity consistently with an effective elastic constant that represents the state of the energy of the membrane. Finally, to demonstrate the applicability of the CBR, we attempt to perform a cellular-scale simulation of migrating keratocyte in which the proposed CBR is used for the membrane protrusion model on the cellular scale. The results show that the experimentally observed shapes of the leading edge are well reproduced by the simulation. In addition, The trend of dependences of the protrusion velocity on the curvature of the leading edge, the temperature, and the substrate stiffness also agreed with the other experimental results. Thus, the CBR can be considered an appropriate cellular-scale model to express the membrane protrusion on the basis of its underlying molecular mechanism.
11. Coarse-graining to the meso and continuum scales with molecular-dynamics-like models
Plimpton, Steve
Many engineering-scale problems that industry or the national labs try to address with particle-based simulations occur at length and time scales well beyond the most optimistic hopes of traditional coarse-graining methods for molecular dynamics (MD), which typically start at the atomic scale and build upward. However classical MD can be viewed as an engine for simulating particles at literally any length or time scale, depending on the models used for individual particles and their interactions. To illustrate I'll highlight several coarse-grained (CG) materials models, some of which are likely familiar to molecular-scale modelers, but others probably not. These include models for water droplet freezing on surfaces, dissipative particle dynamics (DPD) models of explosives where particles have internal state, CG models of nano or colloidal particles in solution, models for aspherical particles, Peridynamics models for fracture, and models of granular materials at the scale of industrial processing. All of these can be implemented as MD-style models for either soft or hard materials; in fact they are all part of our LAMMPS MD package, added either by our group or contributed by collaborators. Unlike most all-atom MD simulations, CG simulations at these scales often involve highly non-uniform particle densities. So I'll also discuss a load-balancing method we've implemented for these kinds of models, which can improve parallel efficiencies. From the physics point-of-view, these models may be viewed as non-traditional or ad hoc. But because they are MD-style simulations, there's an opportunity for physicists to add statistical mechanics rigor to individual models. Or, in keeping with a theme of this session, to devise methods that more accurately bridge models from one scale to the next.
12. Coarse-grained molecular dynamics simulations of depletion-induced interactions for soft matter systems
SciTech Connect
Shendruk, Tyler N.; Bertrand, Martin; Harden, James L.; Slater, Gary W.; Haan, Hendrick W. de
2014-12-28
Given the ubiquity of depletion effects in biological and other soft matter systems, it is desirable to have coarse-grained Molecular Dynamics (MD) simulation approaches appropriate for the study of complex systems. This paper examines the use of two common truncated Lennard-Jones (Weeks-Chandler-Andersen (WCA)) potentials to describe a pair of colloidal particles in a thermal bath of depletants. The shifted-WCA model is the steeper of the two repulsive potentials considered, while the combinatorial-WCA model is the softer. It is found that the depletion-induced well depth for the combinatorial-WCA model is significantly deeper than the shifted-WCA model because the resulting overlap of the colloids yields extra accessible volume for depletants. For both shifted- and combinatorial-WCA simulations, the second virial coefficients and pair potentials between colloids are demonstrated to be well approximated by the Morphometric Thermodynamics (MT) model. This agreement suggests that the presence of depletants can be accurately modelled in MD simulations by implicitly including them through simple, analytical MT forms for depletion-induced interactions. Although both WCA potentials are found to be effective generic coarse-grained simulation approaches for studying depletion effects in complicated soft matter systems, combinatorial-WCA is the more efficient approach as depletion effects are enhanced at lower depletant densities. The findings indicate that for soft matter systems that are better modelled by potentials with some compressibility, predictions from hard-sphere systems could greatly underestimate the magnitude of depletion effects at a given depletant density.
13. Ensemble Empirical Mode Decomposition based methodology for ultrasonic testing of coarse grain austenitic stainless steels.
PubMed
Sharma, Govind K; Kumar, Anish; Jayakumar, T; Purnachandra Rao, B; Mariyappa, N
2015-03-01
A signal processing methodology is proposed in this paper for effective reconstruction of ultrasonic signals in coarse grained high scattering austenitic stainless steel. The proposed methodology is comprised of the Ensemble Empirical Mode Decomposition (EEMD) processing of ultrasonic signals and application of signal minimisation algorithm on selected Intrinsic Mode Functions (IMFs) obtained by EEMD. The methodology is applied to ultrasonic signals obtained from austenitic stainless steel specimens of different grain size, with and without defects. The influence of probe frequency and data length of a signal on EEMD decomposition is also investigated. For a particular sampling rate and probe frequency, the same range of IMFs can be used to reconstruct the ultrasonic signal, irrespective of the grain size in the range of 30-210 μm investigated in this study. This methodology is successfully employed for detection of defects in a 50mm thick coarse grain austenitic stainless steel specimens. Signal to noise ratio improvement of better than 15 dB is observed for the ultrasonic signal obtained from a 25 mm deep flat bottom hole in 200 μm grain size specimen. For ultrasonic signals obtained from defects at different depths, a minimum of 7 dB extra enhancement in SNR is achieved as compared to the sum of selected IMF approach. The application of minimisation algorithm with EEMD processed signal in the proposed methodology proves to be effective for adaptive signal reconstruction with improved signal to noise ratio. This methodology was further employed for successful imaging of defects in a B-scan.
14. Low Frequency-SAFT Inspection Methodology for Coarse-Grained Steel Rail Components (Manganese Steel Frogs)
SciTech Connect
Diaz, Aaron A.; Andersen, Eric S.; Samuel, Todd J.
2004-11-01
In the rail industry, sections of high strength Manganese steel are employed at critical locations in railroad networks. Ultrasonic inspections of Manganese steel microstructures are difficult to inspect with conventional means, as the propagation medium is highly attenuative, coarse-grained, anisotropic and nonhomogeneous in nature. Current in-service inspection methods are ineffective while pre-service X-ray methods (used for full-volumetric examinations of components prior to shipment) are time-consuming, costly, require special facilities and highly trained personnel for safe operations, and preclude manufacturers from inspecting statistically meaningful numbers of frogs for effective quality assurance. In-service examinations consist of visual inspections only and by the time a defect or flaw is visually detected, the structural integrity of the component may already be compromised, and immediate repair or replacement is required. A novel ultrasonic inspection technique utilizing low frequency ultrasound (100 to 500 kHz) combined with a synthetic aperture focusing technique (SAFT) for effective reduction of signal clutter and noise, and extraction of important features in the data, has proven to be effective for these coarse grained steel components. Results from proof-of-principal tests in the laboratory demonstrate an effective means to detect and localize reflectors introduced as a function of size and depth from the top of the frog rail. Using non-optimal, commercially available transducers coupled with the low-frequency/SAFT approach, preliminary evaluations were conducted to study the effects of the material microstructure on ultrasonic propagation, sensitivity and resolution in thick section frog components with machined side-drilled holes. Results from this study will be presented and discussed.
15. Thermal dileptons from coarse-grained transport as fireball probes at SIS energies
Galatyuk, Tetyana; Hohler, Paul M.; Rapp, Ralf; Seck, Florian; Stroth, Joachim
2016-05-01
Utilizing a coarse-graining method to convert hadronic transport simulations of Au+Au collisions at SIS energies into local temperature, baryon and pion densities, we compute the pertinent radiation of thermal dileptons based on an in-medium ρ spectral function that describes available spectra at ultrarelativistic collision energies. In particular, we analyze how far the resulting yields and slopes of the invariant-mass spectra can probe the lifetime and temperatures of the fireball. We find that dilepton radiation sets in after the initial overlap phase of the colliding nuclei of about 7fm/ c, and lasts for about 13fm/ c. This duration closely coincides with the development of the transverse collectivity of the baryons, thus establishing a direct correlation between hadronic collective effects and thermal EM radiation, and supporting a near local equilibration of the system. This fireball "lifetime" is substantially smaller than the typical 20-30fm/ c that naive considerations of the density evolution alone would suggest. We furthermore find that the total dilepton yield radiated into the invariant-mass window of M=0.3 -0.7GeV/ c^2 normalized to the number of charged pions, follows a relation to the lifetime found earlier in the (ultra-) relativistic regime of heavy-ion collisions, and thus corroborates the versatility of this tool. The spectral slopes of the invariant-mass spectra above the φ -meson mass provide a thermometer of the hottest phases of the collision, and agree well with the maximal temperatures extracted from the coarse-grained hadron spectra.
16. Mixing MARTINI: electrostatic coupling in hybrid atomistic-coarse-grained biomolecular simulations.
PubMed
Wassenaar, Tsjerk A; Ingólfsson, Helgi I; Priess, Marten; Marrink, Siewert J; Schäfer, Lars V
2013-04-01
Hybrid molecular dynamics simulations of atomistic (AA) solutes embedded in coarse-grained (CG) environment can substantially reduce the computational cost with respect to fully atomistic simulations. However, interfacing both levels of resolution is a major challenge that includes a balanced description of the relevant interactions. This is especially the case for polar solvents such as water, which screen the electrostatic interactions and thus require explicit electrostatic coupling between AA and CG subsystems. Here, we present and critically test computationally efficient hybrid AA/CG models. We combined the Gromos atomistic force field with the MARTINI coarse-grained force field. To enact electrostatic coupling, two recently developed CG water models with explicit electrostatic interactions were used: the polarizable MARTINI water model and the BMW model. The hybrid model was found to be sensitive to the strength of the AA-CG electrostatic coupling, which was adjusted through the relative dielectric permittivity εr(AA-CG). Potentials of mean force (PMFs) between pairs of amino acid side chain analogues in water and partitioning free enthalpies of uncharged amino acid side chain analogues between apolar solvent and water show significant differences between the hybrid simulations and the fully AA or CG simulations, in particular for charged and polar molecules. For apolar molecules, the results obtained with the hybrid AA/CG models are in better agreement with the fully atomistic results. The structures of atomistic ubiquitin solvated in CG water and of a single atomistic transmembrane α-helix and the transmembrane portion of an atomistic mechanosensitive channel in CG lipid bilayers were largely maintained during 50-100 ns of AA/CG simulations, partly due to an overstabilization of intramolecular interactions. This work highlights some key challenges on the way toward hybrid AA/CG models that are both computationally efficient and sufficiently accurate for
17. Coarse-grained molecular dynamics studies of the concentration and size dependence of fifth- and seventh-generation PAMAM dendrimers on pore formation in DMPC bilayer.
PubMed
Lee, Hwankyu; Larson, Ronald G
2008-07-01
We have performed molecular dynamics (MD) simulations of multiple copies of unacetylated G5 and G7 and acetylated G5 dendrimers in dimyristoylphosphatidylcholine bilayers with explicit water using the coarse-grained model developed by Marrink et al. (J. Phys. Chem. B 2007, 111, 7812) with the inclusion of long-range electrostatics. When initially clustered together near the bilayer, neutral acetylated dendrimers aggregate, whereas cationic unacetylated dendrimers do not aggregate, but separate from each other, similar to the observations from atomic force microscopy by Mecke et al. (Chem. Phys. Lipids 2004, 132, 3). The bilayers interacting with unacetylated dendrimers of higher concentration are significantly deformed and show pore formation on the positively curved portions, while acetylated dendrimers are unable to form pores. Unacetylated G7 dendrimers bring more water molecules into the pores than do unacetylated G5 dendrimers. These results agree qualitatively with experimental results showing that significant cytoplasmic-protein leakage is produced by unacetylated G7 dendrimers at concentrations as low as 10 nM, but only at a much higher concentration of 400 nM for unacetylated G5 dendrimers (Bioconjugate Chem. 2004, 15, 774). This good qualitative agreement indicates that the effect on pore formation of the concentration and size of large nanoparticles can be studied through coarse-grained MD simulations, provided that long-range electrostatic interactions are included.
18. On the second law of thermodynamics: The significance of coarse-graining and the role of decoherence
SciTech Connect
Noorbala, Mahdiyar
2014-12-15
We take up the question why the initial entropy in the universe was small, in the context of evolution of the entropy of a classical system. We note that coarse-graining is an important aspect of entropy evaluation which can reverse the direction of the increase in entropy, i.e., the direction of thermodynamic arrow of time. Then we investigate the role of decoherence in the selection of coarse-graining and explain how to compute entropy for a decohered classical system. Finally, we argue that the requirement of low initial entropy imposes constraints on the decoherence process.
19. Dynamics of the Glycophorin A Dimer in Membranes of Native-Like Composition Uncovered by Coarse-Grained Molecular Dynamics Simulations
PubMed Central
2015-01-01
Membranes are central for cells as borders to the environment or intracellular organelle definition. They are composed of and harbor different molecules like various lipid species and sterols, and they are generally crowded with proteins. The membrane system is very dynamic and components show lateral, rotational and translational diffusion. The consequence of the latter is that phase separation can occur in membranes in vivo and in vitro. It was documented that molecular dynamics simulations of an idealized plasma membrane model result in formation of membrane areas where either saturated lipids and cholesterol (liquid-ordered character, Lo) or unsaturated lipids (liquid-disordered character, Ld) were enriched. Furthermore, current discussions favor the idea that proteins are sorted into the liquid-disordered phase of model membranes, but experimental support for the behavior of isolated proteins in native membranes is sparse. To gain insight into the protein behavior we built a model of the red blood cell membrane with integrated glycophorin A dimer. The sorting and the dynamics of the dimer were subsequently explored by coarse-grained molecular dynamics simulations. In addition, we inspected the impact of lipid head groups and the presence of cholesterol within the membrane on the dynamics of the dimer within the membrane. We observed that cholesterol is important for the formation of membrane areas with Lo and Ld character. Moreover, it is an important factor for the reproduction of the dynamic behavior of the protein found in its native environment. The protein dimer was exclusively sorted into the domain of Ld character in the model red blood cell plasma membrane. Therefore, we present structural information on the glycophorin A dimer distribution in the plasma membrane in the absence of other factors like e.g. lipid anchors in a coarse grain resolution. PMID:26222139
20. Effect of acicular ferrite formation on grain refinement in the coarse-grained region of heat-affected zone
SciTech Connect
Wan, X.L.; Wei, R.; Wu, K.M.
2010-07-15
The microstructure of acicular ferrite and its formation for the grain refinement of coarse-grained region of heat-affected zone of high strength low-alloy bainite steels were studied using three-dimensional reconstruction technique. Crystallographic grain size was analyzed by means of electron backscatter diffraction. It was revealed that the microstructure in the coarse-grained region of the heat-affected zone consisted of predominantly bainite packets and a small proportion of acicular ferrite. Acicular ferrite was of lath or plate-like rather than needle or rod-like morphology. Tempering of the coarse-grained region of heat-affected zone showed that the acicular ferrite was more stable than the bainite, indicating that the acicular ferrite was formed prior to bainite. The acicular ferrite laths or plates divided the prior austenite grains into smaller and separate regions, and confining the bainite transformed at lower temperatures in the smaller regions and hence leading to the grain refinement in the coarse-grained region of the heat-affected zone.
1. Multi-scale coarse-graining of non-conservative interactions in molecular liquids
SciTech Connect
Izvekov, Sergei Rice, Betsy M.
2014-03-14
A new bottom-up procedure for constructing non-conservative (dissipative and stochastic) interactions for dissipative particle dynamics (DPD) models is described and applied to perform hierarchical coarse-graining of a polar molecular liquid (nitromethane). The distant-dependent radial and shear frictions in functional-free form are derived consistently with a chosen form for conservative interactions by matching two-body force-velocity and three-body velocity-velocity correlations along the microscopic trajectories of the centroids of Voronoi cells (clusters), which represent the dissipative particles within the DPD description. The Voronoi tessellation is achieved by application of the K-means clustering algorithm at regular time intervals. Consistently with a notion of many-body DPD, the conservative interactions are determined through the multi-scale coarse-graining (MS-CG) method, which naturally implements a pairwise decomposition of the microscopic free energy. A hierarchy of MS-CG/DPD models starting with one molecule per Voronoi cell and up to 64 molecules per cell is derived. The radial contribution to the friction appears to be dominant for all models. As the Voronoi cell sizes increase, the dissipative forces rapidly become confined to the first coordination shell. For Voronoi cells of two and more molecules the time dependence of the velocity autocorrelation function becomes monotonic and well reproduced by the respective MS-CG/DPD models. A comparative analysis of force and velocity correlations in the atomistic and CG ensembles indicates Markovian behavior with as low as two molecules per dissipative particle. The models with one and two molecules per Voronoi cell yield transport properties (diffusion and shear viscosity) that are in good agreement with the atomistic data. The coarser models produce slower dynamics that can be appreciably attributed to unaccounted dissipation introduced by regular Voronoi re-partitioning as well as by larger
2. First-principles theory, coarse-grained models, and simulations of ferroelectrics.
PubMed
Waghmare, Umesh V
2014-11-18
large-scale simulations while capturing the relevant microscopic interactions quantitatively. In this Account, we first summarize the insights obtained into chemical mechanisms of ferroelectricity using first-principles DFT calculations. We then discuss the principles of construction of first-principles model Hamiltonians for ferroelectric phase transitions in perovskite oxides, which involve coarse-graining in time domain by integrating out high frequency phonons. Molecular dynamics simulations of the resulting model are shown to give quantitative predictions of material-specific ferroelectric transition behavior in bulk as well as nanoscale ferroelectric structures. A free energy landscape obtained through coarse-graining in real-space provides deeper understanding of ferroelectric transitions, domains, and states with inhomogeneous order and points out the key role of microscopic coupling between phonons and strain. We conclude with a discussion of the multiscale modeling strategy elucidated here and its application to other materials such as shape memory alloys.
3. First-principles theory, coarse-grained models, and simulations of ferroelectrics.
PubMed
Waghmare, Umesh V
2014-11-18
large-scale simulations while capturing the relevant microscopic interactions quantitatively. In this Account, we first summarize the insights obtained into chemical mechanisms of ferroelectricity using first-principles DFT calculations. We then discuss the principles of construction of first-principles model Hamiltonians for ferroelectric phase transitions in perovskite oxides, which involve coarse-graining in time domain by integrating out high frequency phonons. Molecular dynamics simulations of the resulting model are shown to give quantitative predictions of material-specific ferroelectric transition behavior in bulk as well as nanoscale ferroelectric structures. A free energy landscape obtained through coarse-graining in real-space provides deeper understanding of ferroelectric transitions, domains, and states with inhomogeneous order and points out the key role of microscopic coupling between phonons and strain. We conclude with a discussion of the multiscale modeling strategy elucidated here and its application to other materials such as shape memory alloys. PMID:25361389
4. Transient β-hairpin formation in α-synuclein monomer revealed by coarse-grained molecular dynamics simulation
Yu, Hang; Han, Wei; Ma, Wen; Schulten, Klaus
2015-12-01
Parkinson's disease, originating from the intrinsically disordered peptide α-synuclein, is a common neurodegenerative disorder that affects more than 5% of the population above age 85. It remains unclear how α-synuclein monomers undergo conformational changes leading to aggregation and formation of fibrils characteristic for the disease. In the present study, we perform molecular dynamics simulations (over 180 μs in aggregated time) using a hybrid-resolution model, Proteins with Atomic details in Coarse-grained Environment (PACE), to characterize in atomic detail structural ensembles of wild type and mutant monomeric α-synuclein in aqueous solution. The simulations reproduce structural properties of α-synuclein characterized in experiments, such as secondary structure content, long-range contacts, chemical shifts, and 3J(HNHCα)-coupling constants. Most notably, the simulations reveal that a short fragment encompassing region 38-53, adjacent to the non-amyloid-β component region, exhibits a high probability of forming a β-hairpin; this fragment, when isolated from the remainder of α-synuclein, fluctuates frequently into its β-hairpin conformation. Two disease-prone mutations, namely, A30P and A53T, significantly accelerate the formation of a β-hairpin in the stated fragment. We conclude that the formation of a β-hairpin in region 38-53 is a key event during α-synuclein aggregation. We predict further that the G47V mutation impedes the formation of a turn in the β-hairpin and slows down β-hairpin formation, thereby retarding α-synuclein aggregation.
5. Transient β-hairpin formation in α-synuclein monomer revealed by coarse-grained molecular dynamics simulation
SciTech Connect
Yu, Hang; Ma, Wen; Han, Wei; Schulten, Klaus
2015-12-28
Parkinson’s disease, originating from the intrinsically disordered peptide α-synuclein, is a common neurodegenerative disorder that affects more than 5% of the population above age 85. It remains unclear how α-synuclein monomers undergo conformational changes leading to aggregation and formation of fibrils characteristic for the disease. In the present study, we perform molecular dynamics simulations (over 180 μs in aggregated time) using a hybrid-resolution model, Proteins with Atomic details in Coarse-grained Environment (PACE), to characterize in atomic detail structural ensembles of wild type and mutant monomeric α-synuclein in aqueous solution. The simulations reproduce structural properties of α-synuclein characterized in experiments, such as secondary structure content, long-range contacts, chemical shifts, and {sup 3}J(H{sub N}H{sub C{sub α}})-coupling constants. Most notably, the simulations reveal that a short fragment encompassing region 38-53, adjacent to the non-amyloid-β component region, exhibits a high probability of forming a β-hairpin; this fragment, when isolated from the remainder of α-synuclein, fluctuates frequently into its β-hairpin conformation. Two disease-prone mutations, namely, A30P and A53T, significantly accelerate the formation of a β-hairpin in the stated fragment. We conclude that the formation of a β-hairpin in region 38-53 is a key event during α-synuclein aggregation. We predict further that the G47V mutation impedes the formation of a turn in the β-hairpin and slows down β-hairpin formation, thereby retarding α-synuclein aggregation.
6. Coarse-grained molecular dynamics simulation of water diffusion in the presence of carbon nanotubes.
PubMed
Lado Touriño, Isabel; Naranjo, Arisbel Cerpa; Negri, Viviana; Cerdán, Sebastián; Ballesteros, Paloma
2015-11-01
Computational modeling of the translational diffusion of water molecules in anisotropic environments entails vital relevance to understand correctly the information contained in the magnetic resonance images weighted in diffusion (DWI) and of the diffusion tensor images (DTI). In the present work we investigated the validity, strengths and weaknesses of a coarse-grained (CG) model based on the MARTINI force field to simulate water diffusion in a medium containing carbon nanotubes (CNTs) as models of anisotropic water diffusion behavior. We show that water diffusion outside the nanotubes follows Ficḱs law, while water diffusion inside the nanotubes is not described by a Ficḱs behavior. We report on the influence on water diffusion of various parameters such as length and concentration of CNTs, comparing the CG results with those obtained from the more accurate classic force field calculation, like the all-atom approach. Calculated water diffusion coefficients decreased in the presence of nanotubes in a concentration dependent manner. We also observed smaller water diffusion coefficients for longer CNTs. Using the CG methodology we were able to demonstrate anisotropic diffusion of water inside the nanotube scaffold, but we could not prove anisotropy in the surrounding medium, suggesting that grouping several water molecules in a single diffusing unit may affect the diffusional anisotropy calculated. The methodologies investigated in this work represent a first step towards the study of more complex models, including anisotropic cohorts of CNTs or even neuronal axons, with reasonable savings in computation time.
7. Coarse-grained Simulations of Chemical Oscillation in Lattice Brusselator System
Rao, Ting; Zhang, Zhen; Hou, Zhong-huai; Xin, Hou-wen
2011-08-01
The oscillation behavior of a two-dimension lattice-gas Brusselator model was investigated. We have adopted a coarse-grained kinetic Monte Carlo (CG-KMC) procedure, where m×m microscopic lattice sites are grouped together to form a CG cell, upon which CG processes take place with well-defined CG rates. Such a CG approach almost fails if the CG rates are obtained by a simple local mean field (s-LMF) approximation, due to the ignorance of correlation among adjcent cells resulting from the trimolecular reaction in this nonlinear system. By proper incorporating such boundary effects, thus introduce the so-called b-LMF CG approach. Extensive numerical simulations demonstrate that the b-LMF method can reproduce the oscillation behavior of the system quite well, given that the diffusion constant is not too small. In addition, the deviation from the KMC results reaches a nearly zero minimum level at an intermediate cell size, which lies in between the effective diffusion length and the minimal size required to sustain a well-defined temporal oscillation.
8. Characterizing DNA Star-Tile-Based Nanostructures Using a Coarse-Grained Model.
PubMed
Schreck, John S; Romano, Flavio; Zimmer, Matthew H; Louis, Ard A; Doye, Jonathan P K
2016-04-26
We use oxDNA, a coarse-grained model of DNA at the nucleotide level, to simulate large nanoprisms that are composed of multi-arm star tiles, in which the size of bulge loops that have been incorporated into the tile design is used to control the flexibility of the tiles. The oxDNA model predicts equilibrium structures for several different nanoprism designs that are in excellent agreement with the experimental structures as measured by cryoTEM. In particular we reproduce the chiral twisting of the top and bottom faces of the nanoprisms, as the bulge sizes in these structures are varied due to the greater flexibility of larger bulges. We are also able to follow how the properties of the star tiles evolve as the prisms are assembled. Individual star tiles are very flexible, but their structures become increasingly well-defined and rigid as they are incorporated into larger assemblies. oxDNA also finds that the experimentally observed prisms are more stable than their inverted counterparts, but interestingly this preference for the arms of the tiles to bend in a given direction only emerges after they are part of larger assemblies. These results show the potential for oxDNA to provide detailed structural insight as well as to predict the properties of DNA nanostructures and hence to aid rational design in DNA nanotechnology. PMID:27010928
9. Characterizing DNA Star-Tile-Based Nanostructures Using a Coarse-Grained Model.
PubMed
Schreck, John S; Romano, Flavio; Zimmer, Matthew H; Louis, Ard A; Doye, Jonathan P K
2016-04-26
We use oxDNA, a coarse-grained model of DNA at the nucleotide level, to simulate large nanoprisms that are composed of multi-arm star tiles, in which the size of bulge loops that have been incorporated into the tile design is used to control the flexibility of the tiles. The oxDNA model predicts equilibrium structures for several different nanoprism designs that are in excellent agreement with the experimental structures as measured by cryoTEM. In particular we reproduce the chiral twisting of the top and bottom faces of the nanoprisms, as the bulge sizes in these structures are varied due to the greater flexibility of larger bulges. We are also able to follow how the properties of the star tiles evolve as the prisms are assembled. Individual star tiles are very flexible, but their structures become increasingly well-defined and rigid as they are incorporated into larger assemblies. oxDNA also finds that the experimentally observed prisms are more stable than their inverted counterparts, but interestingly this preference for the arms of the tiles to bend in a given direction only emerges after they are part of larger assemblies. These results show the potential for oxDNA to provide detailed structural insight as well as to predict the properties of DNA nanostructures and hence to aid rational design in DNA nanotechnology.
10. Coarse-grain molecular dynamics study of fullerene transport across a cell membrane.
PubMed
Sridhar, Akshay; Srikanth, Bharath; Kumar, Amit; Dasmahapatra, Ashok Kumar
2015-07-14
The study of the ability of drug molecules to enter cells through the membrane is of vital importance in the field of drug delivery. In cases where the transport of the drug molecules through the membrane is not easily accomplishable, other carrier molecules are used. Spherical fullerene molecules have been postulated as potential carriers of highly hydrophilic drugs across the plasma membrane. Here, we report the coarse-grain molecular dynamics study of the translocation of C60 fullerene and its derivatives across a cell membrane modeled as a 1,2-distearoyl-sn-glycero-3-phosphocholine bilayer. Simulation results indicate that pristine fullerene molecules enter the bilayer quickly and reside within it. The addition of polar functionalized groups makes the fullerenes less likely to reside within the bilayer but increases their residence time in bulk water. Addition of polar functional groups to one half of the fullerene surface, in effect creating a Janus particle, offers the most promise in developing fullerene models that can achieve complete translocation through the membrane bilayer.
11. Computer simulation of strength and ductility of nanotwin-strengthened coarse-grained metals
Guo, X.; Ji, R.; Weng, G. J.; Zhu, L. L.; Lu, J.
2014-10-01
The superior strength-ductility combination in nanotwin (NT)-strengthened metals has provided a new potential for optimizing the mechanical properties of coarse-grained (CG) metals. In this paper computer simulations based on the mechanism-based strain gradient plasticity and the Johnson-Cook failure criterion have been carried out to uncover the critical factors that serve to provide this dual function. Our results indicate that both the distribution characteristics of the NT regions and the constitutive relations of the NT phase can have a significant impact on the strength and ductility of the CG Cu strengthened by the NT regions. In particular, twin spacing, distribution characteristics such as arrangement, shape and orientation, together with volume fraction of the NT regions, can all have significant effects. Along the way, we also discovered that microcrack initiation, coalescence and deflection constituted the entire failure process. Significant insights into the morphology of NT regions that could deliver superior strength and ductility combination for CG metals have been established.
12. Coarse-grained simulations of poly(propylene imine) dendrimers in solution.
PubMed
Smeijers, A F; Markvoort, A J; Pieterse, K; Hilbers, P A J
2016-02-21
The behavior of poly(propylene imine) (PPI) dendrimers in concentrated solutions has been investigated using molecular dynamics simulations containing up to a thousand PPI dendrimers of generation 4 or 5 in explicit water. To deal with large system sizes and time scales required to study the solutions over a wide range of dendrimer concentrations, a previously published coarse-grained model was applied. Simulation results on the radius of gyration, structure factor, intermolecular spacing, dendrimer interpenetration, and water penetration are compared with available experimental data, providing a clear concentration dependent molecular picture of PPI dendrimers. It is shown that with increasing concentration the dendrimer volume diminishes accompanied by a reduction of internalized water, ultimately resulting in solvent filled cavities between stacked dendrimers. Concurrently dendrimer interpenetration increases only slightly, leaving each dendrimer a separate entity also at high concentrations. Moreover, we compare apparent structure factors, as calculated in experimental studies relying on the decoupling approximation and the constant atomic form factor assumption, with directly computed structure factors. We demonstrate that these already diverge at rather low concentrations, not because of small changes in form factor, but rather because the decoupling approximation fails as monomer positions of separate dendrimers become correlated at concentrations well below the overlap concentration. PMID:26896998
13. A reductionist perspective on quantum statistical mechanics: Coarse-graining of path integrals.
PubMed
Sinitskiy, Anton V; Voth, Gregory A
2015-09-01
Computational modeling of the condensed phase based on classical statistical mechanics has been rapidly developing over the last few decades and has yielded important information on various systems containing up to millions of atoms. However, if a system of interest contains important quantum effects, well-developed classical techniques cannot be used. One way of treating finite temperature quantum systems at equilibrium has been based on Feynman's imaginary time path integral approach and the ensuing quantum-classical isomorphism. This isomorphism is exact only in the limit of infinitely many classical quasiparticles representing each physical quantum particle. In this work, we present a reductionist perspective on this problem based on the emerging methodology of coarse-graining. This perspective allows for the representations of one quantum particle with only two classical-like quasiparticles and their conjugate momenta. One of these coupled quasiparticles is the centroid particle of the quantum path integral quasiparticle distribution. Only this quasiparticle feels the potential energy function. The other quasiparticle directly provides the observable averages of quantum mechanical operators. The theory offers a simplified perspective on quantum statistical mechanics, revealing its most reductionist connection to classical statistical physics. By doing so, it can facilitate a simpler representation of certain quantum effects in complex molecular environments.
14. Coarse-grained model of water diffusion and proton conductivity in hydrated polyelectrolyte membrane
Lee, Ming-Tsung; Vishnyakov, Aleksey; Neimark, Alexander V.
2016-01-01
Using dissipative particle dynamics (DPD), we simulate nanoscale segregation, water diffusion, and proton conductivity in hydrated sulfonated polystyrene (sPS). We employ a novel model [Lee et al. J. Chem. Theory Comput. 11(9), 4395-4403 (2015)] that incorporates protonation/deprotonation equilibria into DPD simulations. The polymer and water are modeled by coarse-grained beads interacting via short-range soft repulsion and smeared charge electrostatic potentials. The proton is introduced as a separate charged bead that forms dissociable Morse bonds with the base beads representing water and sulfonate anions. Morse bond formation and breakup artificially mimics the Grotthuss mechanism of proton hopping between the bases. The DPD model is parameterized by matching the proton mobility in bulk water, dissociation constant of benzenesulfonic acid, and liquid-liquid equilibrium of water-ethylbenzene solutions. The DPD simulations semi-quantitatively predict nanoscale segregation in the hydrated sPS into hydrophobic and hydrophilic subphases, water self-diffusion, and proton mobility. As the hydration level increases, the hydrophilic subphase exhibits a percolation transition from isolated water clusters to a 3D network. The analysis of hydrophilic subphase connectivity and water diffusion demonstrates the importance of the dynamic percolation effect of formation and breakup of temporary junctions between water clusters. The proposed DPD model qualitatively predicts the ratio of proton to water self-diffusion and its dependence on the hydration level that is in reasonable agreement with experiments.
15. Coarse-grained model of water diffusion and proton conductivity in hydrated polyelectrolyte membrane.
PubMed
Lee, Ming-Tsung; Vishnyakov, Aleksey; Neimark, Alexander V
2016-01-01
Using dissipative particle dynamics (DPD), we simulate nanoscale segregation, water diffusion, and proton conductivity in hydrated sulfonated polystyrene (sPS). We employ a novel model [Lee et al. J. Chem. Theory Comput. 11(9), 4395-4403 (2015)] that incorporates protonation/deprotonation equilibria into DPD simulations. The polymer and water are modeled by coarse-grained beads interacting via short-range soft repulsion and smeared charge electrostatic potentials. The proton is introduced as a separate charged bead that forms dissociable Morse bonds with the base beads representing water and sulfonate anions. Morse bond formation and breakup artificially mimics the Grotthuss mechanism of proton hopping between the bases. The DPD model is parameterized by matching the proton mobility in bulk water, dissociation constant of benzenesulfonic acid, and liquid-liquid equilibrium of water-ethylbenzene solutions. The DPD simulations semi-quantitatively predict nanoscale segregation in the hydrated sPS into hydrophobic and hydrophilic subphases, water self-diffusion, and proton mobility. As the hydration level increases, the hydrophilic subphase exhibits a percolation transition from isolated water clusters to a 3D network. The analysis of hydrophilic subphase connectivity and water diffusion demonstrates the importance of the dynamic percolation effect of formation and breakup of temporary junctions between water clusters. The proposed DPD model qualitatively predicts the ratio of proton to water self-diffusion and its dependence on the hydration level that is in reasonable agreement with experiments. PMID:26747818
16. Comparison of thermodynamic properties of coarse-grained and atomic-level simulation models.
PubMed
Baron, Riccardo; Trzesniak, Daniel; de Vries, Alex H; Elsener, Andreas; Marrink, Siewert J; van Gunsteren, Wilfred F
2007-02-19
Thermodynamic data are often used to calibrate or test amomic-level (AL) force fields for molecular dynamics (MD) simulations. In contrast, the majority of coarse-grained (CG) force fields do not rely extensively on thermodynamic quantities. Recently, a CG force field for lipids, hydrocarbons, ions, and water, in which approximately four non-hydrogen atoms are mapped onto one interaction site, has been proposed and applied to study various aspects of lipid systems. To date, no extensive investigation of its capability to describe salvation thermodynamics has been undertaken. In the present study, a detailed picture of vaporization, solvation, and phase-partitioning thermodynamics for liquid hydrocarbons and water was obtained at CG and AL resolutions, in order to compare the two types or models and evaluate their ability to describe thermodynamic properties in the temperature range between 263 and 343 K. Both CG and AL models capture the experimental dependence of the thermodynamic properties on the temperature, albeit a systematically weaker dependence is found for the CG model. Moreover, deviations are found for solvation thermodynamics and for the corresponding enthalpy-entropy compensation for the CG model. Particularly water/oil repulsion seems to be overestimated. However, the results suggest that the thermodynamic properties considered should be reproducible by a CG model provided it is reparametrized on the basis of these liquid-phase properties.
17. Coarse-graining polymer solutions: A critical appraisal of single- and multi-site models
D'Adamo, G.; Menichetti, R.; Pelissetto, A.; Pierleoni, C.
2015-09-01
We critically discuss and review the general ideas behind single- and multi-site coarse-grained (CG) models as applied to macromolecular solutions in the dilute and semi-dilute regime. We first consider single-site models with zero-density and density-dependent pair potentials. We highlight advantages and limitations of each option in reproducing the thermodynamic behavior and the large-scale structure of the underlying reference model. As a case study we consider solutions of linear homopolymers in a solvent of variable quality. Secondly, we extend the discussion to multi-component systems presenting, as a test case, results for mixtures of colloids and polymers. Specifically, we found the CG model with zero-density potentials to be unable to predict fluid-fluid demixing in a reasonable range of densities for mixtures of colloids and polymers of equal size. For larger colloids, the polymer volume fractions at which phase separation occurs are largely overestimated. CG models with density-dependent potentials are somewhat less accurate than models with zero-density potentials in reproducing the thermodynamics of the system and, although they present a phase separation, they significantly underestimate the polymer volume fractions along the binodal. Finally, we discuss a general multi-site strategy, which is thermodynamically consistent and fully transferable with the number of sites, and that allows us to overcome most of the limitations discussed for single-site models.
18. Tension-compression-tension tertiary twins in coarse-grained polycrystalline pure magnesium at room temperature
SciTech Connect
Yu, Qin; Jiang, Yanyao; Wang, Jian
2015-04-07
Using electron backscatter diffraction, the microstructural features of tension–compression–tension (T–C–T) tertiary twins are studied in coarse-grained pure polycrystalline magnesium subjected to monotonic compression along the extrusion direction in ambient air. T–C–T tertiary twins are developed due to the formation of a compression–tension double twin inside a primary tension twin. All the observed T–C–T twin variants are of TiCjTj type. TiCi+1Ti+1 (or TiCi–1Ti–1) variants are observed more frequently than TiCi+2Ti+2 (or TiCi–2Ti–2) variants. Moreover, the number of tertiary twin lamellae increases with the applied compressive strain.
19. Coarse-Grained Modeling of Nucleic Acids Using Anisotropic Gay-Berne and Electric Multipole Potentials.
PubMed
Li, Guohui; Shen, Hujun; Zhang, Dinglin; Li, Yan; Wang, Honglei
2016-02-01
In this work, we attempt to apply a coarse-grained (CG) model, which is based on anisotropic Gay-Berne and electric multipole (EMP) potentials, to the modeling of nucleic acids. First, a comparison has been made between the CG and atomistic models (AMBER point-charge model) in the modeling of DNA and RNA hairpin structures. The CG results have demonstrated a good quality in maintaining the nucleic acid hairpin structures, in reproducing the dynamics of backbone atoms of nucleic acids, and in describing the hydrogen-bonding interactions between nucleic acid base pairs. Second, the CG and atomistic AMBER models yield comparable results in modeling double-stranded DNA and RNA molecules. It is encouraging that our CG model is capable of reproducing many elastic features of nucleic acid base pairs in terms of the distributions of the interbase pair step parameters (such as shift, slide, tilt, and twist) and the intrabase pair parameters (such as buckle, propeller, shear, and stretch). Finally, The GBEMP model has shown a promising ability to predict the melting temperatures of DNA duplexes with different lengths.
20. Hybrid Atomistic and Coarse-Grained Molecular Dynamics Simulations of Polyethylene Glycol (PEG) in Explicit Water.
PubMed
Stanzione, Francesca; Jayaraman, Arthi
2016-05-01
In-silico design of polymeric biomaterials requires molecular dynamics (MD) simulations that retain essential atomistic/molecular details (e.g., explicit water around the biofunctional macromolecule) while simultaneously achieving large length and time scales pertinent to macroscale function. Such large-scale atomistically detailed macromolecular MD simulations with explicit solvent representation are computationally expensive. One way to overcome this limitation is to use an adaptive resolution scheme (AdResS) in which the explicit solvent molecules dynamically adopt either atomistic or coarse-grained resolution depending on their location (e.g., near or far from the macromolecule) in the system. In this study we present the feasibility and the limitations of AdResS methodology for studying polyethylene glycol (PEG) in adaptive resolution water, for varying PEG length and architecture. We first validate the AdResS methodology for such systems, by comparing PEG and solvent structure with that from all-atom simulations. We elucidate the role of the atomistic zone size and the need for calculating thermodynamic force correction within this AdResS approach to correctly reproduce the structure of PEG and water. Lastly, by varying the PEG length and architecture, we study the hydration of PEG, and the effect of PEG architectures on the structural properties of water. Changing the architecture of PEG from linear to multiarm star, we observe reduction in the solvent accessible surface area of the PEG, and an increase in the order of water molecules in the hydration shells. PMID:27108869
1. The discrete-continuum connection in dislocation dynamics: I. Time coarse graining of cross slip
Xia, Shengxu; Belak, James; El-Azab, Anter
2016-10-01
A recent continuum dislocation dynamics formalism (Xia and El-Azab 2015 Model. Simul. Mater. Sci. Eng. 23 055009) has been enriched by incorporating an improved cross slip model. 3D discrete dislocation dynamics simulations were used to collect cross slip rate data in the form of time series that were analysed to estimate the correlation time for cross slip, which was subsequently used as a time scale for local window averaging of the collected cross slip rate data. This time averaging filters out the cross slip rate fluctuations over time intervals less than the correlation time, thus resulting in relatively smoother time series for the cross slip rates. The coarse grained series were further cast in the form of smooth trends with superposed fluctuations and implemented in continuum dislocation dynamics simulations using a Monte Carlo scheme. This approach resulted in a significant improvement of the predicted stress–strain response and a more realistic dislocation cell structure evolution. The similitude law for the average cell size evolution with inverse of stress, however, remains unaffected by the cross slip rates used in continuum dislocation dynamics.
2. Chondrule remelting: Evidence from coarse-grained chondrule rims and compound chondrules
NASA Technical Reports Server (NTRS)
Rubin, A. E.; Krot, A. N.
1994-01-01
The meteorites that best preserve the nebular record are the type 3 ordinary (OC) and carbonaceous chondrites; their major components include chondrules and chondrule fragments, refractory and mafic inclusions, FeO-rich silicate matrix material. Many chondrules are surrounded by nms; these can be divided into two major types: (1) fine-grained rims, which are composed of matrix material; and (2) igneous or coarse-grained rims, which have igneous textures and larger, less-ferroan mafic silicate grains. Fine-grained rims surround most of the chondrules in the least-equilibrated type 3 ordinary and carbonaceous chondrites. They were most likely derived via collapse of clumps of nebular dust that accreted around coarse objects such as chondrules and inclusions. Coarse-grined or igneous rims surround approximately 10% of the chondrules in type 3 OC and approximately 50% of the chondrules in CV3 chondrites as well as some chondrule fragments and isolated mineral grains. They probably formed by partly melting finer-grained dust-rich precursors and admixed chondrule fragments.
3. Coarse-grained simulation study of sequence effects on DNA hybridization in a concentrated environment.
PubMed
Markegard, Cade B; Fu, Iris W; Reddy, K Anki; Nguyen, Hung D
2015-02-01
A novel coarse-grained model is developed to elucidate thermodynamics and kinetic mechanisms of DNA self-assembly. It accounts for sequence and solvent conditions to capture key experimental results such as sequence-dependent thermal property and salt-dependent persistence length of ssDNA and dsDNA. Moreover, constant-temperature simulations on two single strands of a homogeneous sequence show two main mechanisms of hybridization: a slow slithering mechanism and a one-order faster zippering mechanism. Furthermore, large-scale simulations at a high DNA strand concentration demonstrate that DNA self-assembly is a robust and enthalpically driven process in which the formation of double helices is deciphered to occur via multiple self-assembly pathways including the strand displacement mechanism. However, sequence plays an important role in shifting the majority of one pathway over the others and controlling size distribution of self-assembled aggregates. This study yields a complex picture on the role of sequence on programmable self-assembly and demonstrates a promising simulation tool that is suitable for studies in DNA nanotechnology. PMID:25581253
4. Role of neutral lipids in tear fluid lipid layer: coarse-grained simulation study.
PubMed
Telenius, Jelena; Koivuniemi, Artturi; Kulovesi, Pipsa; Holopainen, Juha M; Vattulainen, Ilpo
2012-12-11
Tear fluid lipid layer (TFLL) residing at the air-water interface of tears has been recognized to play an important role in the development of dry eye syndrome. Yet, the composition, structure, and mechanical properties of TFLL are only partly known. Here, we report results of coarse-grained simulations of a lipid layer comprising phospholipids, free fatty acids, cholesteryl esters, and triglycerides at the air-water interface to shed light on the properties of TFLL. We consider structural as well as dynamical properties of the lipid layer as a function of surface pressure. Simulations revealed that neutral lipids reside heterogeneously between phospholipids at relatively low pressures but form a separate hydrophobic phase with increasing surface pressure, transforming the initial lipid monolayer to a two-layered structure. When the model of TFLL was compared to a one-component phospholipid monolayer system, we found drastic differences in both structural and dynamical properties that explain the prominent role of neutral lipids as stabilizers of the TFLL. Based on our results, we suggest that neutral lipids are able to increase the stability of the TFLL by modulating its dynamical and structural behavior, which is important for the proper function of tear film. PMID:23151187
5. Structure and properties of composites based chitosan and carbon nanostructures: atomistic and coarse-grained simulation
Glukhova, O. E.; Kolesnikova, A. S.; Grishina, O. A.; Slepchenkov, M. M.
2015-03-01
At the present time actual task of the modern materials is the creation of biodegradable biocompatible composite materials possessing high strength properties for medical purposes. One of the most promising biomaterials from a position of creation on their basis super strong nanofibres is chitosan. The aim of this work is a theoretical study of the structural features and physico-mechanical properties of biocomposite materials based on chitosan and carbon nanostructures. As matrix nanocomposite we considered various carbon nano-objects, namely carbon nanotubes and graphene. Using the developed original software complex KVAZAR we built atomistic and coarse-grained models of the biocomposite material. To identify regularities of influence of the configuration of the carbon matrix on the mechanical and electronic properties of biocomposite we carried out a series of numerical experiments using a classical algorithm of molecular dynamics and semi-empirical methods. The obtained results allow us to suggest that the generated biocomposite based on chitosan and carbon nanostructures has high stability and strength characteristics. Such materials can be used in biomedicine as a base material for creating of artificial limbs.
6. Freezing Transitions of Nanoconfined Coarse-Grained Water Show Subtle Dependence on Confining Environment.
PubMed
Lu, Qing; Straub, John E
2016-03-10
The solid-to-liquid phase transition in water nanofilms confined between plates, with varying separations and water-plate interactions ranging from strongly hydrophobic to strongly hydrophilic, was simulated using a coarse-grained monatomic water model (mW) and the generalized replica exchange method (gREM). Extensive gREM simulations combined with the statistical temperature weighted histogram analysis method (ST-WHAM) provide a detailed description of the thermodynamic properties intrinsic to the phase transition, including the transition temperature, isobaric heat capacity, phase change enthalpy, entropy, and their dependence on the interplate distance and the plate-water interaction. The ice structure of water nanofilms was characterized at various conditions using the transverse density profile and the distribution of angles formed by hydrogen-bonded neighboring molecules. Flat bilayer ice was observed to be the dominant solid phase at close interplate distance, while puckered bilayer ice, similar to a slab of ice Ih, is the predominant structure at larger interplates. Stable puckered bilayer ice, previously observed to have a low melting point, is observed to have enhanced stability with high melting temperature when confined between hydrophilic plates. These results demonstrate the strong dependence of phase stability and coexistence in nanoconfined systems on the geometry and physical properties of the confining environment. PMID:26906259
7. Detecting synchronization clusters in multivariate time series via coarse-graining of Markov chains
Allefeld, Carsten; Bialonski, Stephan
2007-12-01
Synchronization cluster analysis is an approach to the detection of underlying structures in data sets of multivariate time series, starting from a matrix R of bivariate synchronization indices. A previous method utilized the eigenvectors of R for cluster identification, analogous to several recent attempts at group identification using eigenvectors of the correlation matrix. All of these approaches assumed a one-to-one correspondence of dominant eigenvectors and clusters, which has however been shown to be wrong in important cases. We clarify the usefulness of eigenvalue decomposition for synchronization cluster analysis by translating the problem into the language of stochastic processes, and derive an enhanced clustering method harnessing recent insights from the coarse-graining of finite-state Markov processes. We illustrate the operation of our method using a simulated system of coupled Lorenz oscillators, and we demonstrate its superior performance over the previous approach. Finally we investigate the question of robustness of the algorithm against small sample size, which is important with regard to field applications.
8. Coarse-grained model of water diffusion and proton conductivity in hydrated polyelectrolyte membrane.
PubMed
Lee, Ming-Tsung; Vishnyakov, Aleksey; Neimark, Alexander V
2016-01-01
Using dissipative particle dynamics (DPD), we simulate nanoscale segregation, water diffusion, and proton conductivity in hydrated sulfonated polystyrene (sPS). We employ a novel model [Lee et al. J. Chem. Theory Comput. 11(9), 4395-4403 (2015)] that incorporates protonation/deprotonation equilibria into DPD simulations. The polymer and water are modeled by coarse-grained beads interacting via short-range soft repulsion and smeared charge electrostatic potentials. The proton is introduced as a separate charged bead that forms dissociable Morse bonds with the base beads representing water and sulfonate anions. Morse bond formation and breakup artificially mimics the Grotthuss mechanism of proton hopping between the bases. The DPD model is parameterized by matching the proton mobility in bulk water, dissociation constant of benzenesulfonic acid, and liquid-liquid equilibrium of water-ethylbenzene solutions. The DPD simulations semi-quantitatively predict nanoscale segregation in the hydrated sPS into hydrophobic and hydrophilic subphases, water self-diffusion, and proton mobility. As the hydration level increases, the hydrophilic subphase exhibits a percolation transition from isolated water clusters to a 3D network. The analysis of hydrophilic subphase connectivity and water diffusion demonstrates the importance of the dynamic percolation effect of formation and breakup of temporary junctions between water clusters. The proposed DPD model qualitatively predicts the ratio of proton to water self-diffusion and its dependence on the hydration level that is in reasonable agreement with experiments.
9. Defining the membrane disruption mechanism of kalata B1 via coarse-grained molecular dynamics simulations
PubMed Central
Nawae, Wanapinun; Hannongbua, Supa; Ruengjitchatchawalya, Marasri
2014-01-01
Kalata B1 has been demonstrated to have bioactivity relating to membrane disruption. In this study, we conducted coarse-grained molecular dynamics simulations to gain further insight into kB1 bioactivity. The simulations were performed at various concentrations of kB1 to capture the overall progression of its activity. Two configurations of kB1 oligomers, termed tower-like and wall-like clusters, were detected. The conjugation between the wall-like oligomers resulted in the formation of a ring-like hollow in the kB1 cluster on the membrane surface. Our results indicated that the molecules of kB1 were trapped at the membrane-water interface. The interfacial membrane binding of kB1 induced a positive membrane curvature, and the lipids were eventually extracted from the membrane through the kB1 ring-like hollow into the space inside the kB1 cluster. These findings provide an alternative view of the mechanism of kB1 bioactivity that corresponds with the concept of an interfacial bioactivity model. PMID:24492660
10. Introducing improved structural properties and salt dependence into a coarse-grained model of DNA
SciTech Connect
Snodin, Benedict E. K. Mosayebi, Majid; Schreck, John S.; Romano, Flavio; Doye, Jonathan P. K.; Randisi, Ferdinando; Šulc, Petr; Ouldridge, Thomas E.; Tsukanov, Roman; Nir, Eyal; Louis, Ard A.
2015-06-21
We introduce an extended version of oxDNA, a coarse-grained model of deoxyribonucleic acid (DNA) designed to capture the thermodynamic, structural, and mechanical properties of single- and double-stranded DNA. By including explicit major and minor grooves and by slightly modifying the coaxial stacking and backbone-backbone interactions, we improve the ability of the model to treat large (kilobase-pair) structures, such as DNA origami, which are sensitive to these geometric features. Further, we extend the model, which was previously parameterised to just one salt concentration ([Na{sup +}] = 0.5M), so that it can be used for a range of salt concentrations including those corresponding to physiological conditions. Finally, we use new experimental data to parameterise the oxDNA potential so that consecutive adenine bases stack with a different strength to consecutive thymine bases, a feature which allows a more accurate treatment of systems where the flexibility of single-stranded regions is important. We illustrate the new possibilities opened up by the updated model, oxDNA2, by presenting results from simulations of the structure of large DNA objects and by using the model to investigate some salt-dependent properties of DNA.
11. The Effect of Tethers on Artificial Cell Membranes: A Coarse-Grained Molecular Dynamics Study
PubMed Central
Hoiles, William; Gupta, Rini; Cornell, Bruce; Krishnamurthy, Vikram
2016-01-01
Tethered bilayer lipid membranes (tBLMs) provide a stable platform for modeling the dynamics and order of biological membranes where the tethers mimic the cytoskeletal supports present in biological cell membranes. In this paper coarse-grained molecular dynamics (CGMD) is applied to study the effects of tethers on lipid membrane properties. Using results from the CGMD model and the overdamped Fokker-Planck equation, we show that the diffusion tensor and particle density of water in the tBLM is spatially dependent. Further, it is shown that the membrane thickness, lipid diffusion, defect density, free energy of lipid flip-flop, and membrane dielectric permittivity are all dependent on the tether density. The numerically computed results from the CGMD model are in agreement with the experimentally measured results from tBLMs containing different tether densities and lipids derived from Archaebacteria. Additionally, using experimental measurements from Escherichia coli bacteria and Saccharomyces Cerevisiae yeast tethered membranes, we illustrate how previous molecular dynamics results can be combined with the proposed model to estimate the dielectric permittivity and defect density of these membranes as a function of tether density. PMID:27736860
12. Concurrent parametrization against static and kinetic information leads to more robust coarse-grained force fields
Rudzinski, J. F.; Bereau, T.
2016-07-01
The parametrization of coarse-grained (CG) simulation models for molecular systems often aims at reproducing static properties alone. The reduced molecular friction of the CG representation usually results in faster, albeit inconsistent, dynamics. In this work, we rely on Markov state models to simultaneously characterize the static and kinetic properties of two CG peptide force fields—one top-down and one bottom-up. Instead of a rigorous evolution of CG dynamics (e.g., using a generalized Langevin equation), we attempt to improve the description of kinetics by simply altering the existing CG models, which employ standard Langevin dynamics. By varying masses and relevant force-field parameters, we can improve the timescale separation of the slow kinetic processes, achieve a more consistent ratio of mean-first-passage times between metastable states, and refine the relative free-energies between these states. Importantly, we show that the incorporation of kinetic information into a structure-based parametrization improves the description of the helix-coil transition sampled by a minimal CG model. While structure-based models understabilize the helical state, kinetic constraints help identify CG models that improve the ratio of forward/backward timescales by effectively hindering the sampling of spurious conformational intermediate states.
13. Algorithm for simulation of quantum many-body dynamics using dynamical coarse-graining
SciTech Connect
Khasin, M.; Kosloff, R.
2010-04-15
An algorithm for simulation of quantum many-body dynamics having su(2) spectrum-generating algebra is developed. The algorithm is based on the idea of dynamical coarse-graining. The original unitary dynamics of the target observables--the elements of the spectrum-generating algebra--is simulated by a surrogate open-system dynamics, which can be interpreted as weak measurement of the target observables, performed on the evolving system. The open-system state can be represented by a mixture of pure states, localized in the phase space. The localization reduces the scaling of the computational resources with the Hilbert-space dimension n by factor n{sup 3/2}(ln n){sup -1} compared to conventional sparse-matrix methods. The guidelines for the choice of parameters for the simulation are presented and the scaling of the computational resources with the Hilbert-space dimension of the system is estimated. The algorithm is applied to the simulation of the dynamics of systems of 2x10{sup 4} and 2x10{sup 6} cold atoms in a double-well trap, described by the two-site Bose-Hubbard model.
14. Coarse-grained molecular dynamics simulations of the tensile behavior of a thermosetting polymer
Yang, Shaorui; Qu, Jianmin
2014-07-01
Using a previously developed coarse-grained model, we conducted large-scale (˜85×85×85nm3) molecular dynamics simulations of uniaxial-strain deformation to study the tensile behavior of an epoxy molding compound, epoxy phenol novolacs (EPN) bisphenol A (BPA). Under the uniaxial-strain deformation, the material is found to exhibit cavity nucleation and growth, followed by stretching of the ligaments separated by the cavities, until the ultimate failure through ligament scissions. The nucleation sites of cavities are rather random and the subsequent cavity growth accounts for much (87%) of the volumetric change during the uniaxial-strain deformation. Ultimate failure of the materials occurs when the cavity volume fraction reaches ˜60%. During the entire deformation process, polymer strands in the network are continuously extended to their linear states and broken in the postyielding strain hardening stage. When most of the strands are stretched to their taut configurations, rapid scission of a large number of strands occurs within a small strain increment, which eventually leads to fracture. Finally, through extensive numerical simulations of various loading conditions in addition to uniaxial strain, we find that yielding of the EPN-BPA can be described by the pressure-modified von Mises yield criterion.
15. Region-Oriented Placement Algorithm for Coarse-Grained Power-Gating FPGA Architecture
Li, Ce; Dong, Yiping; Watanabe, Takahiro
An FPGA plays an essential role in industrial products due to its fast, stable and flexible features. But the power consumption of FPGAs used in portable devices is one of critical issues. Top-down hierarchical design method is commonly used in both ASIC and FPGA design. But, in the case where plural modules are integrated in an FPGA and some of them might be in sleep-mode, current FPGA architecture cannot be fully effective. In this paper, coarse-grained power gating FPGA architecture is proposed where a whole area of an FPGA is partitioned into several regions and power supply is controlled for each region, so that modules in sleep mode can be effectively power-off. We also propose a region oriented FPGA placement algorithm fitted to this user's hierarchical design based on VPR[1]. Simulation results show that this proposed method could reduce power consumption of FPGA by 38% on average by setting unused modules or regions in sleep mode.
16. Application-specific coarse-grained reconfigurable array: architecture and design methodology
Zhou, Li; Liu, Dongpei; Zhang, Jianfeng; Liu, Hengzhu
2015-06-01
Coarse-grained reconfigurable arrays (CGRAs) have shown potential for application in embedded systems in recent years. Numerous reconfigurable processing elements (PEs) in CGRAs provide flexibility while maintaining high performance by exploring different levels of parallelism. However, a difference remains between the CGRA and the application-specific integrated circuit (ASIC). Some application domains, such as software-defined radios (SDRs), require flexibility with performance demand increases. More effective CGRA architectures are expected to be developed. Customisation of a CGRA according to its application can improve performance and efficiency. This study proposes an application-specific CGRA architecture template composed of generic PEs (GPEs) and special PEs (SPEs). The hardware of the SPE can be customised to accelerate specific computational patterns. An automatic design methodology that includes pattern identification and application-specific function unit generation is also presented. A mapping algorithm based on ant colony optimisation is provided. Experimental results on the SDR target domain show that compared with other ordinary and application-specific reconfigurable architectures, the CGRA generated by the proposed method performs more efficiently for given applications.
17. Universal and non-universal features in coarse-grained models of flow in disordered solids.
PubMed
Nicolas, Alexandre; Martens, Kirsten; Bocquet, Lydéric; Barrat, Jean-Louis
2014-07-14
We study the two-dimensional (2D) shear flow of amorphous solids within variants of an elastoplastic model, paying particular attention to spatial correlations and time fluctuations of, e.g., local stresses. The model is based on the local alternation between an elastic regime and plastic events during which the local stress is redistributed. The importance of a fully tensorial description of the stress and of the inclusion of (coarse-grained) convection in the model is investigated; scalar and tensorial models yield similar results, while convection enhances fluctuations and breaks the spurious symmetry between the flow and velocity gradient directions, for instance when shear localisation is observed. Besides, correlation lengths measured with diverse protocols are discussed. One class of such correlation lengths simply scale with the spacing between homogeneously distributed, simultaneous plastic events. This leads to a scaling of the correlation length with the shear rate as γ̇(-1/2) in 2D in the athermal regime, regardless of the details of the model. The radius of the cooperative disk, defined as the near-field region in which plastic events induce a stress redistribution that is not amenable to a mean-field treatment, notably follows this scaling. On the other hand, the cooperative volume measured from the four-point stress susceptibility and its dependence on the system size and the shear rate are model-dependent.
18. Freezing Transitions of Nanoconfined Coarse-Grained Water Show Subtle Dependence on Confining Environment.
PubMed
Lu, Qing; Straub, John E
2016-03-10
The solid-to-liquid phase transition in water nanofilms confined between plates, with varying separations and water-plate interactions ranging from strongly hydrophobic to strongly hydrophilic, was simulated using a coarse-grained monatomic water model (mW) and the generalized replica exchange method (gREM). Extensive gREM simulations combined with the statistical temperature weighted histogram analysis method (ST-WHAM) provide a detailed description of the thermodynamic properties intrinsic to the phase transition, including the transition temperature, isobaric heat capacity, phase change enthalpy, entropy, and their dependence on the interplate distance and the plate-water interaction. The ice structure of water nanofilms was characterized at various conditions using the transverse density profile and the distribution of angles formed by hydrogen-bonded neighboring molecules. Flat bilayer ice was observed to be the dominant solid phase at close interplate distance, while puckered bilayer ice, similar to a slab of ice Ih, is the predominant structure at larger interplates. Stable puckered bilayer ice, previously observed to have a low melting point, is observed to have enhanced stability with high melting temperature when confined between hydrophilic plates. These results demonstrate the strong dependence of phase stability and coexistence in nanoconfined systems on the geometry and physical properties of the confining environment.
19. Sound velocity fluctuations in confined granular materials: Coarse-graining lengths and elastic heterogeneities
van den Wildenberg, Siet; Tourin, Arnaud; Jia, Xiaoping
2016-08-01
We measure the consequences of elastic heterogeneities in confined granular layers using long-wavelength sound velocity determination. By progressively decreasing the coarse-graining length w, which is determined here by the sample size L, we measure the standard deviation of the longitudinal sound velocity δ VL and the packing density ϕ, normalized by their ensemble-averaged values. We find that the relative fluctuations in V L and ϕ increase when w is decreased. Importantly, we observe that decreasing the confining pressure P or using nonspherical particles leads to an important increase of the fluctuations in δ V_L/\\bar{V_L} . We conduct simulations of sound propagation in 2D hexagonal packings with contact-stiffness disorder to mimic the inhomogeneous contact networks. The sound velocity fluctuations of coherent longitudinal waves increase either with decreasing the sample size or with increasing the elastic disorder related to confining pressure, in consistency with the experiments. Our experimental observations thus support the scenario of a pressure-dependent mesoscopic length ξ∼10d (at P∼200 \\text{kPa} ), below which the continuum elasticity breaks down, likely due to the large spatial fluctuation of the shear modulus δ G/\\bar{G} ∼ 5δ V_L/\\bar{V_L}>20% .
20. Coarse-grained molecular dynamics modeling of the kinetics of lamellar block copolymer defect annealing
Peters, Andrew J.; Lawson, Richard A.; Nation, Benjamin D.; Ludovice, Peter J.; Henderson, Clifford L.
2016-01-01
State-of-the-art block copolymer (BCP)-directed self-assembly (DSA) methods still yield defect densities orders of magnitude higher than is necessary in semiconductor fabrication despite free-energy calculations that suggest equilibrium defect densities are much lower than is necessary for economic fabrication. This disparity suggests that the main problem may lie in the kinetics of defect removal. This work uses a coarse-grained model to study the rates, pathways, and dependencies of healing a common defect to give insight into the fundamental processes that control defect healing and give guidance on optimal process conditions for BCP-DSA. It is found that bulk simulations yield an exponential drop in defect heal rate above χN˜30. Thin films show no change in rate associated with the energy barrier below χN˜50, significantly higher than the χN values found previously for self-consistent field theory studies that neglect fluctuations. Above χN˜50, the simulations show an increase in energy barrier scaling with 1/2 to 1/3 of the bulk systems. This is because thin films always begin healing at the free interface or the BCP-underlayer interface, where the increased A-B contact area associated with the transition state is minimized, while the infinitely thick films cannot begin healing at an interface.
1. A transferable coarse-grained model for diphenylalanine: How to represent an environment driven conformational transition
SciTech Connect
Dalgicdir, Cahit; Sensoy, Ozge; Sayar, Mehmet; Peter, Christine
2013-12-21
One of the major challenges in the development of coarse grained (CG) simulation models that aim at biomolecular structure formation processes is the correct representation of an environment-driven conformational change, for example, a folding/unfolding event upon interaction with an interface or upon aggregation. In the present study, we investigate this transferability challenge for a CG model using the example of diphenylalanine. This dipeptide displays a transition from a trans-like to a cis-like conformation upon aggregation as well as upon transfer from bulk water to the cyclohexane/water interface. Here, we show that one can construct a single CG model that can reproduce both the bulk and interface conformational behavior and the segregation between hydrophobic/hydrophilic medium. While the general strategy to obtain nonbonded interactions in the present CG model is to reproduce solvation free energies of small molecules representing the CG beads in the respective solvents, the success of the model strongly depends on nontrivial decisions one has to make to capture the delicate balance between the bonded and nonbonded interactions. In particular, we found that the peptide's conformational behavior is qualitatively affected by the cyclohexane/water interaction potential, an interaction that does not directly involve the peptide at all but merely influences the properties of the hydrophobic/hydrophilic interface. Furthermore, we show that a small modification to improve the structural/conformational properties of the CG model could dramatically alter the thermodynamic properties.
2. Connecting Macroscopic Observables and Microscopic Assembly Events in Amyloid Formation Using Coarse Grained Simulations
PubMed Central
Bieler, Noah S.; Knowles, Tuomas P. J.; Frenkel, Daan; Vácha, Robert
2012-01-01
The pre-fibrillar stages of amyloid formation have been implicated in cellular toxicity, but have proved to be challenging to study directly in experiments and simulations. Rational strategies to suppress the formation of toxic amyloid oligomers require a better understanding of the mechanisms by which they are generated. We report Dynamical Monte Carlo simulations that allow us to study the early stages of amyloid formation. We use a generic, coarse-grained model of an amyloidogenic peptide that has two internal states: the first one representing the soluble random coil structure and the second one the -sheet conformation. We find that this system exhibits a propensity towards fibrillar self-assembly following the formation of a critical nucleus. Our calculations establish connections between the early nucleation events and the kinetic information available in the later stages of the aggregation process that are commonly probed in experiments. We analyze the kinetic behaviour in our simulations within the framework of the theory of classical nucleated polymerisation, and are able to connect the structural events at the early stages in amyloid growth with the resulting macroscopic observables such as the effective nucleus size. Furthermore, the free-energy landscapes that emerge from these simulations allow us to identify pertinent properties of the monomeric state that could be targeted to suppress oligomer formation. PMID:23071427
3. Morphologies of charged diblock copolymers simulated with a neutral coarse-grained model.
PubMed
Pantano, Diego A; Klein, Michael L; Discher, Dennis E; Moore, Preston B
2011-04-28
We present the results of coarse grained molecular dynamics simulation using a charge free model that is able to capture different regions of the morphological phase diagram of charged diblock copolymers. Specifically, we were able to reproduce many phases of the poly(acrylic acid)-(1,4)-polybutadiene (PAA-PBA) diblock copolymer, Ca(2+) and water systems as a function of pH and calcium concentration with short-range LJ type potentials. The morphologies observed range from bilayers to cylinders to spherical micelles. Such polyanionic/cationic amphiphiles in water typically present multiple challenges for molecular simulations, particularly due to the many charge interactions that are long ranged and computationally costly. Further, it is precisely these interactions that are thought to modulate large amphiphile assemblies of interest such as lipid rafts. However, our model is able to reproduce different morphologies due to pH and with or without the addition of Ca(2+) as well as the lateral phase segregation and the domain registration observed in neutral and charged diblock copolymer mixtures. The results suggest that the overall effect of charges is a local structural rearrangement that renormalizes the steric repulsion between the headgroups. This simple model, which is devoid of charges, is able to reproduce the complex phase diagram and can be used to investigate collective phenomena in these charged systems such as domain formation and registration or colocalization of lipid rafts across bilayer leaflets.
4. Coarse-Grained Modeling of Nucleic Acids Using Anisotropic Gay-Berne and Electric Multipole Potentials.
PubMed
Li, Guohui; Shen, Hujun; Zhang, Dinglin; Li, Yan; Wang, Honglei
2016-02-01
In this work, we attempt to apply a coarse-grained (CG) model, which is based on anisotropic Gay-Berne and electric multipole (EMP) potentials, to the modeling of nucleic acids. First, a comparison has been made between the CG and atomistic models (AMBER point-charge model) in the modeling of DNA and RNA hairpin structures. The CG results have demonstrated a good quality in maintaining the nucleic acid hairpin structures, in reproducing the dynamics of backbone atoms of nucleic acids, and in describing the hydrogen-bonding interactions between nucleic acid base pairs. Second, the CG and atomistic AMBER models yield comparable results in modeling double-stranded DNA and RNA molecules. It is encouraging that our CG model is capable of reproducing many elastic features of nucleic acid base pairs in terms of the distributions of the interbase pair step parameters (such as shift, slide, tilt, and twist) and the intrabase pair parameters (such as buckle, propeller, shear, and stretch). Finally, The GBEMP model has shown a promising ability to predict the melting temperatures of DNA duplexes with different lengths. PMID:26717419
5. Path Integral Coarse-Graining Replica Exchange Method for Enhanced Sampling.
PubMed
Peng, Yuxing; Cao, Zhen; Zhou, Ruhong; Voth, Gregory A
2014-09-01
An enhanced conformational space sampling method is developed that utilizes replica exchange molecular dynamics between a set of imaginary time Feynman path integral replicas, each having an increasing degree of contraction (or coarse-graining) of the quasi-particle or "polymer beads" in the evaluation of the isomorphic ring-polymer potential energy terms. However, there is no contraction of beads in the effectively harmonic kinetic energy terms. The final replica in this procedure is the fully contracted one in which the potential energy is evaluated only at the centroid of the beads-and hence it is the classical distribution in the centroid variable-while the initial replica has the full degree (or even a heightened degree, if desired) of quantum delocalization and tunneling in the physical potential by the polymer necklace beads. The exchange between the different ring-polymer ensembles is governed by the Metropolis criteria to guarantee detailed balance. The method is applied successfully to several model systems, ranging from one-dimensional prototype rough energy landscape models having analytical solutions to the more realistic alanine dipeptide. A detailed comparison with the classical temperature-based replica exchange method shows an improved efficiency of this new method in the classical conformational space sampling due to coupling with the fictitious path integral (quantum) replicas. PMID:26588508
6. Derivation of coarse-grained potentials via multistate iterative Boltzmann inversion
SciTech Connect
Moore, Timothy C.; Iacovella, Christopher R. E-mail: [email protected]; McCabe, Clare E-mail: [email protected]
2014-06-14
In this work, an extension is proposed to the standard iterative Boltzmann inversion (IBI) method used to derive coarse-grained potentials. It is shown that the inclusion of target data from multiple states yields a less state-dependent potential, and is thus better suited to simulate systems over a range of thermodynamic states than the standard IBI method. The inclusion of target data from multiple states forces the algorithm to sample regions of potential phase space that match the radial distribution function at multiple state points, thus producing a derived potential that is more representative of the underlying interactions. It is shown that the algorithm is able to converge to the true potential for a system where the underlying potential is known. It is also shown that potentials derived via the proposed method better predict the behavior of n-alkane chains than those derived via the standard IBI method. Additionally, through the examination of alkane monolayers, it is shown that the relative weight given to each state in the fitting procedure can impact bulk system properties, allowing the potentials to be further tuned in order to match the properties of reference atomistic and/or experimental systems.
7. A Coarse-Grained Model for Thermoresponsive Poly(N-isopropylacrylamide)
Abbott, Lauren J.; Stevens, Mark J.
Poly(N-isopropylacrylamide) (PNIPAM) is a thermoresponsive polymer that undergoes a phase transition at its lower critical solution temperature (LCST). Although atomistic simulations have been effective to study PNIPAM single chains in solution, they are limited in reaching longer length- and time-scales. In this work, a coarse-grained (CG) model is developed for PNIPAM that captures its thermoresponsive behavior. Nonbonded parameters are fit to experimental thermodynamic data, with minor adjustments to provide better agreement with radial distribution functions from atomistic simulations. Bonded parameters are fit to probability distributions from atomistic simulations using multi-centered Gaussian-based potentials. The temperature-dependent potentials derived for the CG model in this work properly capture the coil-globule transition of PNIPAM single chains and yield a chain-length dependence consistent with atomistic simulations and experiment. The self-assembly of PNIPAM surfactants is also explored. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.
8. A reductionist perspective on quantum statistical mechanics: Coarse-graining of path integrals
SciTech Connect
Sinitskiy, Anton V.; Voth, Gregory A.
2015-09-07
Computational modeling of the condensed phase based on classical statistical mechanics has been rapidly developing over the last few decades and has yielded important information on various systems containing up to millions of atoms. However, if a system of interest contains important quantum effects, well-developed classical techniques cannot be used. One way of treating finite temperature quantum systems at equilibrium has been based on Feynman’s imaginary time path integral approach and the ensuing quantum-classical isomorphism. This isomorphism is exact only in the limit of infinitely many classical quasiparticles representing each physical quantum particle. In this work, we present a reductionist perspective on this problem based on the emerging methodology of coarse-graining. This perspective allows for the representations of one quantum particle with only two classical-like quasiparticles and their conjugate momenta. One of these coupled quasiparticles is the centroid particle of the quantum path integral quasiparticle distribution. Only this quasiparticle feels the potential energy function. The other quasiparticle directly provides the observable averages of quantum mechanical operators. The theory offers a simplified perspective on quantum statistical mechanics, revealing its most reductionist connection to classical statistical physics. By doing so, it can facilitate a simpler representation of certain quantum effects in complex molecular environments.
9. A coarse-grain force field for RDX: Density dependent and energy conserving.
PubMed
Moore, Joshua D; Barnes, Brian C; Izvekov, Sergei; Lísal, Martin; Sellers, Michael S; Taylor, DeCarlos E; Brennan, John K
2016-03-14
We describe the development of a density-dependent transferable coarse-grain model of crystalline hexahydro-1,3,5-trinitro-s-triazine (RDX) that can be used with the energy conserving dissipative particle dynamics method. The model is an extension of a recently reported one-site model of RDX that was developed by using a force-matching method. The density-dependent forces in that original model are provided through an interpolation scheme that poorly conserves energy. The development of the new model presented in this work first involved a multi-objective procedure to improve the structural and thermodynamic properties of the previous model, followed by the inclusion of the density dependency via a conservative form of the force field that conserves energy. The new model accurately predicts the density, structure, pressure-volume isotherm, bulk modulus, and elastic constants of the RDX crystal at ambient pressure and exhibits transferability to a liquid phase at melt conditions. PMID:26979691
10. A Coarse Grained Model for Methylcellulose: Spontaneous Ring Formation at Elevated Temperature
Huang, Wenjun; Larson, Ronald
Methylcellulose (MC) is widely used as food additives and pharma applications, where its thermo-reversible gelation behavior plays an important role. To date the gelation mechanism is not well understood, and therefore attracts great research interest. In this study, we adopted coarse-grained (CG) molecular dynamics simulations to model the MC chains, including the homopolymers and random copolymers that models commercial METHOCEL A, in an implicit water environment, where each MC monomer modeled with a single bead. The simulations are carried using a LAMMPS program. We parameterized our CG model using the radial distribution functions from atomistic simulations of short MC oligomers, extrapolating the results to long chains. We used dissociation free energy to validate our CG model against the atomistic model. The CG model captured the effects of monomer substitution type and temperature from the atomistic simulations. We applied this CG model to simulate single chains up to 1000 monomers long and obtained persistence lengths that are close to those determined from experiment. We observed the chain collapse transition for random copolymer at 600 monomers long at 50C. The chain collapsed into a stable ring structure with outer diameter around 14nm, which appears to be a precursor to the fibril structure observed in the methylcellulose gel observed by Lodge et al. in the recent studies. Our CG model can be extended to other MC derivatives for studying the interaction between these polymers and small molecules, such as hydrophobic drugs.
11. Dynamics of micelle-nanoparticle systems undergoing shear. A coarse-grained molecular dynamics approach
SciTech Connect
Rolfe, Bryan A.; Chun, Jaehun; Joo, Yong L.
2013-09-05
Recent experimental work has shown that polymeric micelles can template nanoparticles via interstitial sites in shear-ordered micelle solutions. In the current study, we report simulation results based on a coarse-grained molecular dynamics (CGMD) model of a solvent/polymer/nanoparticle system. Our results demonstrate the importance of polymer concentration and the micelle corona length in 2D shear-ordering of neat block copolymer solutions. Although our results do not show strong 3D ordering during shear, we find that cessation of shear allows the system to relax into a 3D configuration of greater order than without shear. It is further shown that this post-shear relaxation is strongly dependent on the length of the micelle corona. For the first time, we demonstrate the presence and importance of a flow disturbance surrounding micelles in simple shear flow at moderate Péclet numbers. This disturbance is similar to what is observed around simulated star polymers and ellipsoids. The extent of the flow disturbance increases as expected with a longer micelle corona length. It is further suggested that without proper consideration of these dynamics, a stable nanoparticle configuration would be difficult to obtain.
12. Large-scale structural transitions in supercoiled DNA revealed by coarse-grained simulations
Topological constraints, such as DNA supercoiling, play an integral role in genomic regulation and organization in living systems. However, physical understanding of the principles that underlie DNA structure and organization at biologically-relevant length-scales remains a formidable challenge. We develop a coarse-grained simulation approach for predicting equilibrium conformations of supercoiled DNA. With this approach, we study the conformational transitions that arise due to supercoiling across the full range of supercoiling densities that are commonly explored by living systems. Simulations of ring DNA molecules with lengths up to the scale of topological domains in the E. coli chromosome (~10 kilobases) reveal large-scale structural transitions elicited by supercoiling, resulting in 3 supercoiling conformational regimes: chiral coils, extended plectonemes, and branched hyper-supercoils. These results capture the non-monotonic relationship of size versus degree of supercoiling observed in experimental sedimentation studies of supercoiled DNA, and our results provide a physical explanation of the structural transitions underlying this behavior.
13. A coarse-grained generalized second law for holographic conformal field theories
Bunting, William; Fu, Zicao; Marolf, Donald
2016-03-01
We consider the universal sector of a d\\gt 2 dimensional large-N strongly interacting holographic CFT on a black hole spacetime background B. When our CFT d is coupled to dynamical Einstein-Hilbert gravity with Newton constant G d , the combined system can be shown to satisfy a version of the thermodynamic generalized second law (GSL) at leading order in G d . The quantity {S}{CFT}+\\frac{A({H}B,{perturbed})}{4{G}d} is non-decreasing, where A({H}B,{perturbed}) is the (time-dependent) area of the new event horizon in the coupled theory. Our S CFT is the notion of (coarse-grained) CFT entropy outside the black hole given by causal holographic information—a quantity in turn defined in the AdS{}d+1 dual by the renormalized area {A}{ren}({H}{{bulk}}) of a corresponding bulk causal horizon. A corollary is that the fine-grained GSL must hold for finite processes taken as a whole, though local decreases of the fine-grained generalized entropy are not obviously forbidden. Another corollary, given by setting {G}d=0, states that no finite process taken as a whole can increase the renormalized free energy F={E}{out}-{{TS}}{CFT}-{{Ω }}J, with T,{{Ω }} constants set by {H}B. This latter corollary constitutes a 2nd law for appropriate non-compact AdS event horizons.
14. A reductionist perspective on quantum statistical mechanics: Coarse-graining of path integrals.
PubMed
Sinitskiy, Anton V; Voth, Gregory A
2015-09-01
Computational modeling of the condensed phase based on classical statistical mechanics has been rapidly developing over the last few decades and has yielded important information on various systems containing up to millions of atoms. However, if a system of interest contains important quantum effects, well-developed classical techniques cannot be used. One way of treating finite temperature quantum systems at equilibrium has been based on Feynman's imaginary time path integral approach and the ensuing quantum-classical isomorphism. This isomorphism is exact only in the limit of infinitely many classical quasiparticles representing each physical quantum particle. In this work, we present a reductionist perspective on this problem based on the emerging methodology of coarse-graining. This perspective allows for the representations of one quantum particle with only two classical-like quasiparticles and their conjugate momenta. One of these coupled quasiparticles is the centroid particle of the quantum path integral quasiparticle distribution. Only this quasiparticle feels the potential energy function. The other quasiparticle directly provides the observable averages of quantum mechanical operators. The theory offers a simplified perspective on quantum statistical mechanics, revealing its most reductionist connection to classical statistical physics. By doing so, it can facilitate a simpler representation of certain quantum effects in complex molecular environments. PMID:26342356
15. Sedimentology and hydrodynamic implications of a coarse-grained hurricane sequence in a carbonate reef setting
USGS Publications Warehouse
Spiske, M.; Jaffe, B.E.
2009-01-01
Storms and associated surges are major coast-shaping processes. Nevertheless, no typical sequences for storm surge deposits in different coastal settings have been established. This study interprets a coarse-grained hurricane ridge deposit on the island of Bonaire, Netherlands Antilles. The sequence was deposited during Hurricane Lenny in November 1999. Insight is gained into the hydrodynamics of surge flow by interpreting textural trends, particle imbrication, and deposit geometry. Vertical textural variations, caused by time-dependent hydrodynamic changes, were used to subdivide the deposit into depositional units that correspond to different stages of the surge, such as setup, peak, and return flow. Particle size and imbrication trends and geometry of the units reflect landward bed-load transport of components during the setup, a nondirectional flow with sediment falling out of suspension during the peak, and a seaward bedload transport during the return flow. Formation of a ridge during setup affected the texture of the return flow unit. Changing angles of imbrication reflect alternating flow velocities during each phase. Normal grading during setup and inverse grading during return flow are caused by decelerating and accelerating flow, respectively. Hence, the interpreted deposit seems to represent the first described complete hurricane surge sequence from a carbonate environment. ?? 2009 Geological Society of America.
16. Mechanisms and Kinetics of Amyloid Aggregation Investigated by a Phenomenological Coarse-Grained Model
Magno, Andrea; Pellarin, Riccardo; Caflisch, Amedeo
Amyloid fibrils are ordered polypeptide aggregates that have been implicated in several neurodegenerative pathologies, such as Alzheimer's, Parkinson's, Huntington's, and prion diseases, [1, 2] and, more recently, also in biological functionalities. [3, 4, 5] These findings have paved the way for a wide range of experimental and computational studies aimed at understanding the details of the fibril-formation mechanism. Computer simulations using low-resolution models, which employ a simplified representation of protein geometry and energetics, have provided insights into the basic physical principles underlying protein aggregation in general [6, 7, 8] and ordered amyloid aggregation. [9, 10, 11, 12, 13, 14, 15] For example, Dokholyan and coworkers have used the Discrete Molecular Dynamics method [16, 17] to shed light on the mechanisms of protein oligomerization [18] and the conformational changes that take place in proteins before the aggregation onset. [19, 20] One challenging observation, which is difficult to observe by computer simulations, is the wide range of aggregation scenarios emerging from a variety of biophysical measurements. [21, 22] Atomistic models have been employed to study the conformational space of amyloidogenic polypeptides in the monomeric state, [23, 24, 25] the very initial steps of amyloid formation, [26, 27, 28, 29, 30, 31, 32] and the structural stability of fibril models. [33, 34, 35) However, all-atom simulations of the kinetics of fibril formation are beyond what can be done with modern computers.
17. Coding coarse grained polymer model for LAMMPS and its application to polymer crystallization
Luo, Chuanfu; Sommer, Jens-Uwe
2009-08-01
We present a patch code for LAMMPS to implement a coarse grained (CG) model of poly(vinyl alcohol) (PVA). LAMMPS is a powerful molecular dynamics (MD) simulator developed at Sandia National Laboratories. Our patch code implements tabulated angular potential and Lennard-Jones-9-6 (LJ96) style interaction for PVA. Benefited from the excellent parallel efficiency of LAMMPS, our patch code is suitable for large-scale simulations. This CG-PVA code is used to study polymer crystallization, which is a long-standing unsolved problem in polymer physics. By using parallel computing, cooling and heating processes for long chains are simulated. The results show that chain-folded structures resembling the lamellae of polymer crystals are formed during the cooling process. The evolution of the static structure factor during the crystallization transition indicates that long-range density order appears before local crystalline packing. This is consistent with some experimental observations by small/wide angle X-ray scattering (SAXS/WAXS). During the heating process, it is found that the crystalline regions are still growing until they are fully melted, which can be confirmed by the evolution both of the static structure factor and average stem length formed by the chains. This two-stage behavior indicates that melting of polymer crystals is far from thermodynamic equilibrium. Our results concur with various experiments. It is the first time that such growth/reorganization behavior is clearly observed by MD simulations. Our code can be easily used to model other type of polymers by providing a file containing the tabulated angle potential data and a set of appropriate parameters. Program summaryProgram title: lammps-cgpva Catalogue identifier: AEDE_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEDE_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GNU's GPL No. of lines in distributed program
18. Energy-efficient specialization of functional units in a Coarse-Grained Reconfigurable Array
SciTech Connect
Van Essen, B; Panda, R; Wood, A; Ebeling, C; Hauck, S
2010-12-01
Functional units provide the backbone of any spatial accelerator by providing the computing resources. The desire for having rich and expensive functional units is in tension with producing a regular and energy-efficient computing fabric. This paper explores the design trade-off between complex, universal functional units and simpler, limited functional units. We show that a modest amount of specialization reduces the area-delay-energy product of an optimized architecture to 0.86x a baseline architecture. Furthermore, we provide a design guideline that allows an architect to customize the contents of the computing fabric just by examining the profile of benchmarks within the application domains. Functional units are the core of compute-intensive spatial accelerators. They perform the computation of interest with support from local storage and communication structures. Ideally, the functional units will provide rich functionality, supporting operations ranging from simple addition, to fused multiply-adds, to advanced transcendental functions and domain specific operations like add-compare-select. However, the total opportunity cost to support the more complex operations is a function of the cost of the hardware, the rate of occurrence of the operation in the application domain, and the inefficiency of emulating the operation with simpler operators. Examples of operations that are typically emulated in spatial accelerators are division and trigonometric functions, which can be solved using table-lookup based algorithms and the CORDIC algorithm. One reason to avoid having direct hardware support for complex operations in a tiled architecture like a Coarse-Grained Reconfigurable Array (CGRA) is that the expensive hardware will typically need to be replicated in some or all of the architecture's tiles. Tiled architecture are designed such that their tiles are either homogeneous or heterogeneous. Homogeneous architectures are simpler to design but heterogeneous
19. Assembly of Influenza Hemagglutinin Fusion Peptides in a Phospholipid Bilayer by Coarse-grained Computer Simulations
PubMed Central
Collu, Francesca; Spiga, Enrico; Lorenz, Christian D.; Fraternali, Franca
2015-01-01
Membrane fusion is critical to eukaryotic cellular function and crucial to the entry of enveloped viruses such as influenza and human immunodeficiency virus. Influenza viral entry in the host cell is mediated by a 20–23 amino acid long sequence, called the fusion peptide (FP). Recently, possible structures for the fusion peptide (ranging from an inverted V shaped α-helical structure to an α-helical hairpin, or to a complete α-helix) and their implication in the membrane fusion initiation have been proposed. Despite the large number of studies devoted to the structure of the FP, the mechanism of action of this peptide remains unclear with several mechanisms having been suggested, including the induction of local disorder, promoting membrane curvature, and/or altering local membrane composition. In recent years, several research groups have employed atomistic and/or coarse-grained molecular dynamics (MD) simulations to investigate the matter. In all previous works, the behavior of a single FP monomer was studied, while in this manuscript, we use a simplified model of a tripeptide (TP) monomer of FP (TFP) instead of a single FP monomer because each Influenza Hemagglutinin contains three FP molecules in the biological system. In this manuscript we report findings targeted at understanding the fusogenic properties and the collective behavior of these trimers of FP peptides on a 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine model membrane. Here we show how the TFP monomers self-assemble into differently sized oligomers in the presence of the membrane. We measure the perturbation to the structure of the phospholipid membrane caused by the presence of these TFP oligomers. Our work (i) shows how self-assembly of TFP in the presence of the membrane induces non negligible deformation to the membrane and (ii) could be a useful starting point to stimulate discussion and further work targeted to fusion pore formation. PMID:26636093
20. Role of Ionic Clusters in Dynamics of Ionomer Melts: From Atomistic to Coarse Grained Simulations
Agrawal, Anupriya
Ionomers, polymers decorated with ionizable groups, have found application in numerous technologies where ionic transport is required. The ionic groups associate into random clusters resulting in substantial effect on structure, dynamics and transport of these materials. The effects of topology, size and dynamics of these aggregates however remain an open question. Here we probe cluster formation correlated with polymer dynamics through a model system of randomly sulfonated polystyrene (SPS) melts with molecular dynamics (MD) simulations over a broad time and length scales ranging from that within the ionic clusters through polymer segmental dynamics to the motion of the entire molecules. The cluster evolution was probed by fully atomistic studies. We find ladder-like aggregates that transform to globule-like with increasing the dielectric constant of media for sodium neutralized SPS. With increasing dielectric constant, the size of the aggregates decrease and their number increases. Concurrently, the mobility of the polymer increases. The counterion radius and valency affect both morphology and dynamics as is evident in the calculated static and dynamic structure factors. It is further manifested in the results of viscosity obtained through non-equilibrium molecular dynamics technique. Finally, to access larger length scales a three bead coarse-grained model to describe sulfonated styrene that we have developed will be discussed in view of the outstanding challenges in ionic polymers. Supported in part by DOE Grant No. DE-SC007908. This work was carried out in collaboration with Dvora Perahia and Gary Grest while I was a postdoc at Clemson University. I gratefully acknowledge both of them for their support and encouragement.
1. Coarse-grained molecular dynamics modeling of the kinetics of lamellar BCP defect annealing
Peters, Andrew J.; Lawson, Richard A.; Nation, Benjamin D.; Ludovice, Peter J.; Henderson, Clifford L.
2015-03-01
Directed self-assembly of block copolymers (BCPs) is a process that has received great interest in the field of nanomanufacturing in the past decade, and great strides towards forming high quality aligned patterns have been made. But state of the art methods still yield defectivities orders of magnitude higher than is necessary in semi-conductor fabrication even though free energy calculations suggest that equilibrium defectivities are much lower than is necessary for economic semi-conductor fabrication. This disparity suggests that the main problem may lie in the kinetics of defect removal. This work uses a coarse-grained model to study the rates, pathways, and dependencies of healing a common defect to give insight into the fundamental processes that control defect healing and give guidance on optimal process conditions for BCP-DSA. It is found that infinitely thick films yield an exponential drop in defect heal rate above χN ~ 30. Below χN ~ 30, the rate of transport was similar to the rate at which the transition state was reached so that the overall rate changed only slightly. The energy barrier in periodic simulations increased with 0.31 χN on average. Thin film simulations show no change in rate associated with the energy barrier below χN ~ 50, and then show an increase in energy barrier scaling with 0.16χN. Thin film simulations always begin to heal at either the free interface or the BCP-underlayer interface where the increased A-B contact area associated with the transition state will be minimized, while the infinitely thick films must start healing in the bulk where the A-B contact area is increased. It is also found that cooperative chain movement is required for the defect to start healing.
2. Coarse-grained event tree analysis for quantifying Hodgkin-Huxley neuronal network dynamics.
PubMed
Sun, Yi; Rangan, Aaditya V; Zhou, Douglas; Cai, David
2012-02-01
We present an event tree analysis of studying the dynamics of the Hodgkin-Huxley (HH) neuronal networks. Our study relies on a coarse-grained projection to event trees and to the event chains that comprise these trees by using a statistical collection of spatial-temporal sequences of relevant physiological observables (such as sequences of spiking multiple neurons). This projection can retain information about network dynamics that covers multiple features, swiftly and robustly. We demonstrate that for even small differences in inputs, some dynamical regimes of HH networks contain sufficiently higher order statistics as reflected in event chains within the event tree analysis. Therefore, this analysis is effective in discriminating small differences in inputs. Moreover, we use event trees to analyze the results computed from an efficient library-based numerical method proposed in our previous work, where a pre-computed high resolution data library of typical neuronal trajectories during the interval of an action potential (spike) allows us to avoid resolving the spikes in detail. In this way, we can evolve the HH networks using time steps one order of magnitude larger than the typical time steps used for resolving the trajectories without the library, while achieving comparable statistical accuracy in terms of average firing rate and power spectra of voltage traces. Our numerical simulation results show that the library method is efficient in the sense that the results generated by using this numerical method with much larger time steps contain sufficiently high order statistical structure of firing events that are similar to the ones obtained using a regular HH solver. We use our event tree analysis to demonstrate these statistical similarities.
3. Experimental deformation of coarse-grained rock salt to high strain
Linckens, J.; Zulauf, G.; Hammer, J.
2016-08-01
The processes and deformation mechanisms (e.g., dislocation creep, pressure solution, grain boundary sliding, and recrystallization) of rock salt are still a matter of debate. In order to fill this gap, high strain constriction experiments at 345°C, atmospheric pressure and a strain rate of 10-7 s-1 have been conducted on natural halite cuboids (60 × 60 × 45 mm) from the Morsleben mine of Northern Germany. Most samples were almost single crystals and contain a small amount of smaller grains (10-26%). The grain boundaries are decorated with fluid inclusions. The experiments were stopped at different final strains (ɛy = z of 10, 20, 30, and 40%) corresponding to a maximum strain (ɛx) range of 20-170%. The halite is deformed by dislocation creep, and the size of developed subgrains corresponds to the applied stress. The combined Schmid factor and subgrain boundary analysis indicate that slip was largely accommodated by the {110} < 110 > slip systems, with possible minor contribution by slip on the {100} < 110 > slip systems. Some of the deformed samples show evidence of grain boundary migration. In addition, subgrains with small misorientations form that result in large cumulative misorientations within a single grain (>40°). However, no subgrain rotation recrystallization is observed (i.e., misorientation angles are <10°). All the experiments show strain hardening, suggesting that recrystallization by grain boundary migration was not extensive and did not reset the microstructure. The experiments show that high finite strain in coarse-grained relatively dry rock salt can be accommodated by dislocation creep, without extensive dynamic recrystallization.
4. Pattern formation and coarse-graining in two-dimensional colloids driven by multiaxial magnetic fields.
PubMed
Müller, Kathrin; Osterman, Natan; Babič, Dušan; Likos, Christos N; Dobnikar, Jure; Nikoubashman, Arash
2014-05-13
We study the pattern formation in a two-dimensional system of superparamagnetic colloids interacting via spatially coherent induced interactions driven by an external precessing magnetic field. On the pair level, upon changing the opening angle of the external field, the interactions smoothly vary from purely repulsive (opening angle equal to zero) to purely attractive (time-averaged pair interactions at an opening angle of 90°). In the experiments, we observed ordered hexagonal crystals at the repulsive end and coarsening frothlike structures for purely attractive interactions. In both of these limiting cases, the dense colloidal systems can be sufficiently accurately described by assuming pairwise additivity of the interaction potentials. However, for a range of intermediate angles, pronounced many-body depolarization effects compete with the direct induced interactions, resulting in inherently anisotropic effective interactions. Under such conditions, we observed the decay of hexagonal order with the concomitant formation of short chains and percolated networks of chains coexisting with free colloids. In order to describe and investigate these systems theoretically, we developed a coarse-grained model of a binary mixture of patchy and nonpatchy particles with the ratio of patchy and nonpatchy colloids as the order parameter. Combining genetic algorithms with Monte Carlo simulations, we optimized the model parameters and quantitatively reproduced the experimentally observed sequence of colloidal structures. The results offer new insight into the anisotropy induced by the many-body effects. At the same time, they allow for a very efficient description of the system by means of a pairwise-additive Hamiltonian, whereupon the original, one-component system features a two-component mixture of isotropic and patchy colloids.
5. Why do arginine and lysine organize lipids differently? Insights from coarse-grained and atomistic simulations.
PubMed
Wu, Zhe; Cui, Qiang; Yethiraj, Arun
2013-10-10
An important puzzle in membrane biophysics is the difference in the behaviors of lysine (Lys) and arginine (Arg) based peptides at the membrane. For example, the translocation of poly-Arg is orders of magnitude faster than that of poly-Lys. Recent experimental work suggests that much of the difference can be inferred from the phase behavior of peptide/lipid mixtures. At similar concentrations, mixtures of phosphatidylethanolamine (PE) and phosphatidylserine (PS) lipids display different phases in the presence of these polypeptides, with a bicontinuous phase observed with poly-Arg peptides and an inverted hexagonal phase observed with poly-Lys peptides. Here we show that simulations with the coarse-grained (CG) BMW-MARTINI model reproduce the experimental results. An analysis using atomistic and CG models reveals that electrostatic and glycerol-peptide interactions play a crucial role in determining the phase behavior of peptide-lipid mixtures, with the difference between Arg and Lys arising from the stronger interactions of the former with lipid glycerols. In other words, the multivalent nature of the guanidinium group allows Arg to simultaneously interact with both phosphate and glycerol groups, while Lys engages solely with phosphate; this feature of amino acid/lipid interactions has not been emphasized in previous studies. The Arg peptides colocalize with PS in regions of high negative Gaussian curvature and stabilize the bicontinuous phase. Decreasing the strength of either the electrostatic interactions or the peptide-glycerol interactions causes the inverted hexagonal phase to become more stable. The results highlight the utility of CG models for the investigation of phase behavior but also emphasize the subtlety of the phenomena, with small changes in specific interactions leading to qualitatively different phases. PMID:24024591
6. Characterization of grain boundary impedances in fine- and coarse-grained CaCu3Ti4O12 ceramics
Adams, Timothy B.; Sinclair, Derek C.; West, Anthony R.
2006-03-01
The influence of electrode material, dc bias, and pellet thickness on the electrical properties of fine- and coarse-grained CaCu3Ti4O12 (CCTO) ceramics has been investigated using impedance spectroscopy. The low frequency arc observed in Z* plots near room temperature is independent of the electron work function of the metal electrode. It shows significant variation with dc bias and pellet thickness for coarse-grained ceramics, but no such variations for fine-grained ceramics. The results demonstrate the importance of ceramic microstructure in controlling the electrical properties of CCTO ceramics and support the internal barrier layer capacitor (IBLC) model of Schottky barriers at the grain boundaries between semiconducting grains. The IBLC model explains the high permittivity and nonlinear current-voltage characteristics commonly reported for CCTO ceramics.
7. An improved fast multipole method for electrostatic potential calculations in a class of coarse-grained molecular simulations
2014-08-01
This paper presents a novel algorithm to approximate the long-range electrostatic potential field in the Cartesian coordinates applicable to 3D coarse-grained simulations of biopolymers. In such models, coarse-grained clusters are formed via treating groups of atoms as rigid and/or flexible bodies connected together via kinematic joints. Therefore, multibody dynamic techniques are used to form and solve the equations of motion of such coarse-grained systems. In this article, the approximations for the potential fields due to the interaction between a highly negatively/positively charged pseudo-atom and charged particles, as well as the interaction between clusters of charged particles, are presented. These approximations are expressed in terms of physical and geometrical properties of the bodies such as the entire charge, the location of the center of charge, and the pseudo-inertia tensor about the center of charge of the clusters. Further, a novel substructuring scheme is introduced to implement the presented far-field potential evaluations in a binary tree framework as opposed to the existing quadtree and octree strategies of implementing fast multipole method. Using the presented Lagrangian grids, the electrostatic potential is recursively calculated via sweeping two passes: assembly and disassembly. In the assembly pass, adjacent charged bodies are combined together to form new clusters. Then, the potential field of each cluster due to its interaction with faraway resulting clusters is recursively calculated in the disassembly pass. The method is highly compatible with multibody dynamic schemes to model coarse-grained biopolymers. Since the proposed method takes advantage of constant physical and geometrical properties of rigid clusters, improvement in the overall computational cost is observed comparing to the tradition application of fast multipole method.
8. Bottom-up coarse-grained models that accurately describe the structure, pressure, and compressibility of molecular liquids
SciTech Connect
Dunn, Nicholas J. H.; Noid, W. G.
2015-12-28
The present work investigates the capability of bottom-up coarse-graining (CG) methods for accurately modeling both structural and thermodynamic properties of all-atom (AA) models for molecular liquids. In particular, we consider 1, 2, and 3-site CG models for heptane, as well as 1 and 3-site CG models for toluene. For each model, we employ the multiscale coarse-graining method to determine interaction potentials that optimally approximate the configuration dependence of the many-body potential of mean force (PMF). We employ a previously developed “pressure-matching” variational principle to determine a volume-dependent contribution to the potential, U{sub V}(V), that approximates the volume-dependence of the PMF. We demonstrate that the resulting CG models describe AA density fluctuations with qualitative, but not quantitative, accuracy. Accordingly, we develop a self-consistent approach for further optimizing U{sub V}, such that the CG models accurately reproduce the equilibrium density, compressibility, and average pressure of the AA models, although the CG models still significantly underestimate the atomic pressure fluctuations. Additionally, by comparing this array of models that accurately describe the structure and thermodynamic pressure of heptane and toluene at a range of different resolutions, we investigate the impact of bottom-up coarse-graining upon thermodynamic properties. In particular, we demonstrate that U{sub V} accounts for the reduced cohesion in the CG models. Finally, we observe that bottom-up coarse-graining introduces subtle correlations between the resolution, the cohesive energy density, and the “simplicity” of the model.
9. Bottom-up coarse-grained models that accurately describe the structure, pressure, and compressibility of molecular liquids
Dunn, Nicholas J. H.; Noid, W. G.
2015-12-01
The present work investigates the capability of bottom-up coarse-graining (CG) methods for accurately modeling both structural and thermodynamic properties of all-atom (AA) models for molecular liquids. In particular, we consider 1, 2, and 3-site CG models for heptane, as well as 1 and 3-site CG models for toluene. For each model, we employ the multiscale coarse-graining method to determine interaction potentials that optimally approximate the configuration dependence of the many-body potential of mean force (PMF). We employ a previously developed "pressure-matching" variational principle to determine a volume-dependent contribution to the potential, UV(V), that approximates the volume-dependence of the PMF. We demonstrate that the resulting CG models describe AA density fluctuations with qualitative, but not quantitative, accuracy. Accordingly, we develop a self-consistent approach for further optimizing UV, such that the CG models accurately reproduce the equilibrium density, compressibility, and average pressure of the AA models, although the CG models still significantly underestimate the atomic pressure fluctuations. Additionally, by comparing this array of models that accurately describe the structure and thermodynamic pressure of heptane and toluene at a range of different resolutions, we investigate the impact of bottom-up coarse-graining upon thermodynamic properties. In particular, we demonstrate that UV accounts for the reduced cohesion in the CG models. Finally, we observe that bottom-up coarse-graining introduces subtle correlations between the resolution, the cohesive energy density, and the "simplicity" of the model.
10. Applying Ultrasonic Phased Array Technology to Examine Austenitic Coarse-Grained Structures for Light Water Reactor Piping
SciTech Connect
Anderson, Michael T.; Cumblidge, Stephen E.; Doctor, Steven R.
2003-12-18
Pacific Northwest Laboratory is evaluating the capabilities and limitations of phased array (PA) technology to detect service-type flaws in coarse-grained austenitic piping structures. The work is being sponsored by the U.S. Nuclear Regulatory Commission, Office of Research. This paper presents initial work involving the use of PA technology to determine the effectiveness of detecting and accurately characterizing flaws on the far-side of austenitic piping welds.
11. A comparative study of coarse-graining methods for polymeric fluids: Mori-Zwanzig vs. iterative Boltzmann inversion vs. stochastic parametric optimization
Li, Zhen; Bian, Xin; Yang, Xiu; Karniadakis, George Em
2016-07-01
We construct effective coarse-grained (CG) models for polymeric fluids by employing two coarse-graining strategies. The first one is a forward-coarse-graining procedure by the Mori-Zwanzig (MZ) projection while the other one applies a reverse-coarse-graining procedure, such as the iterative Boltzmann inversion (IBI) and the stochastic parametric optimization (SPO). More specifically, we perform molecular dynamics (MD) simulations of star polymer melts to provide the atomistic fields to be coarse-grained. Each molecule of a star polymer with internal degrees of freedom is coarsened into a single CG particle and the effective interactions between CG particles can be either evaluated directly from microscopic dynamics based on the MZ formalism, or obtained by the reverse methods, i.e., IBI and SPO. The forward procedure has no free parameters to tune and recovers the MD system faithfully. For the reverse procedure, we find that the parameters in CG models cannot be selected arbitrarily. If the free parameters are properly defined, the reverse CG procedure also yields an accurate effective potential. Moreover, we explain how an aggressive coarse-graining procedure introduces the many-body effect, which makes the pairwise potential invalid for the same system at densities away from the training point. From this work, general guidelines for coarse-graining of polymeric fluids can be drawn.
12. Quantum Mechanics/Molecular Mechanics Method Combined with Hybrid All-Atom and Coarse-Grained Model: Theory and Application on Redox Potential Calculations.
PubMed
Shen, Lin; Yang, Weitao
2016-04-12
We developed a new multiresolution method that spans three levels of resolution with quantum mechanical, atomistic molecular mechanical, and coarse-grained models. The resolution-adapted all-atom and coarse-grained water model, in which an all-atom structural description of the entire system is maintained during the simulations, is combined with the ab initio quantum mechanics and molecular mechanics method. We apply this model to calculate the redox potentials of the aqueous ruthenium and iron complexes by using the fractional number of electrons approach and thermodynamic integration simulations. The redox potentials are recovered in excellent accordance with the experimental data. The speed-up of the hybrid all-atom and coarse-grained water model renders it computationally more attractive. The accuracy depends on the hybrid all-atom and coarse-grained water model used in the combined quantum mechanical and molecular mechanical method. We have used another multiresolution model, in which an atomic-level layer of water molecules around redox center is solvated in supramolecular coarse-grained waters for the redox potential calculations. Compared with the experimental data, this alternative multilayer model leads to less accurate results when used with the coarse-grained polarizable MARTINI water or big multipole water model for the coarse-grained layer.
13. A comparative study of coarse-graining methods for polymeric fluids: Mori-Zwanzig vs. iterative Boltzmann inversion vs. stochastic parametric optimization.
PubMed
Li, Zhen; Bian, Xin; Yang, Xiu; Karniadakis, George Em
2016-07-28
We construct effective coarse-grained (CG) models for polymeric fluids by employing two coarse-graining strategies. The first one is a forward-coarse-graining procedure by the Mori-Zwanzig (MZ) projection while the other one applies a reverse-coarse-graining procedure, such as the iterative Boltzmann inversion (IBI) and the stochastic parametric optimization (SPO). More specifically, we perform molecular dynamics (MD) simulations of star polymer melts to provide the atomistic fields to be coarse-grained. Each molecule of a star polymer with internal degrees of freedom is coarsened into a single CG particle and the effective interactions between CG particles can be either evaluated directly from microscopic dynamics based on the MZ formalism, or obtained by the reverse methods, i.e., IBI and SPO. The forward procedure has no free parameters to tune and recovers the MD system faithfully. For the reverse procedure, we find that the parameters in CG models cannot be selected arbitrarily. If the free parameters are properly defined, the reverse CG procedure also yields an accurate effective potential. Moreover, we explain how an aggressive coarse-graining procedure introduces the many-body effect, which makes the pairwise potential invalid for the same system at densities away from the training point. From this work, general guidelines for coarse-graining of polymeric fluids can be drawn. PMID:27475343
14. On the Investigation of Coarse-Grained Models for Water: Balancing Computational Efficiency and the Retention of Structural Properties
PubMed Central
2010-01-01
Developing accurate models of water for use in computer simulations is important for the study of many chemical and biological systems, including lipid bilayer self-assembly. The large temporal and spatial scales needed to study such self-assembly have led to the development and application of coarse-grained models for the lipid-lipid, lipid-solvent and solvent-solvent interactions. Unfortunately, popular center-of-mass-based coarse-graining techniques are limited to modeling water with one-water per bead. In this work, we have utilized the K-means algorithm to determine the optimal clustering of waters to allow the mapping of multiple waters to single coarse-grained beads. Through the study of a simple mixture between water and an amphiphilic solute (1-pentanol), we find a 4-water bead model has the optimal balance between computational efficiency and accurate solvation and structural properties when compared to water models ranging from 1 to 9 waters per bead. The 4-water model was subsequently utilized in studies of the solvation of hexadecanoic acid and the structure, as measured via radial distribution functions, for the hydrophobic tails and the bulk water phase were found to agree well with experimental data and their atomistic targets. PMID:20230012
15. Coarse-grained models using local-density potentials optimized with the relative entropy: Application to implicit solvation
Sanyal, Tanmoy; Shell, M. Scott
2016-07-01
Bottom-up multiscale techniques are frequently used to develop coarse-grained (CG) models for simulations at extended length and time scales but are often limited by a compromise between computational efficiency and accuracy. The conventional approach to CG nonbonded interactions uses pair potentials which, while computationally efficient, can neglect the inherently multibody contributions of the local environment of a site to its energy, due to degrees of freedom that were coarse-grained out. This effect often causes the CG potential to depend strongly on the overall system density, composition, or other properties, which limits its transferability to states other than the one at which it was parameterized. Here, we propose to incorporate multibody effects into CG potentials through additional nonbonded terms, beyond pair interactions, that depend in a mean-field manner on local densities of different atomic species. This approach is analogous to embedded atom and bond-order models that seek to capture multibody electronic effects in metallic systems. We show that the relative entropy coarse-graining framework offers a systematic route to parameterizing such local density potentials. We then characterize this approach in the development of implicit solvation strategies for interactions between model hydrophobes in an aqueous environment.
16. Coherent-state path integral versus coarse-grained effective stochastic equation of motion: From reaction diffusion to stochastic sandpiles
Wiese, Kay Jörg
2016-04-01
We derive and study two different formalisms used for nonequilibrium processes: the coherent-state path integral, and an effective, coarse-grained stochastic equation of motion. We first study the coherent-state path integral and the corresponding field theory, using the annihilation process A +A →A as an example. The field theory contains counterintuitive quartic vertices. We show how they can be interpreted in terms of a first-passage problem. Reformulating the coherent-state path integral as a stochastic equation of motion, the noise generically becomes imaginary. This renders it not only difficult to interpret, but leads to convergence problems at finite times. We then show how alternatively an effective coarse-grained stochastic equation of motion with real noise can be constructed. The procedure is similar in spirit to the derivation of the mean-field approximation for the Ising model, and the ensuing construction of its effective field theory. We finally apply our findings to stochastic Manna sandpiles. We show that the coherent-state path integral is inappropriate, or at least inconvenient. As an alternative, we derive and solve its mean-field approximation, which we then use to construct a coarse-grained stochastic equation of motion with real noise.
17. Coarse-graining scheme for simulating uniaxial stress-strain response of glassy polymers through molecular dynamics.
PubMed
Majumder, Manoj K; S, Ramkumar; Mahajan, Dhiraj K; Basu, Sumit
2010-01-01
Simulation of the deformation of polymers below their glass transition through molecular dynamics provides an useful route to correlate their molecular architecture to deformation behavior. However, present computational capabilities severely restrict the time and length scales that can be simulated when detailed models of these macromolecules are used. Coarse-graining techniques for macromolecular structures intend to make bigger and longer simulations possible by grouping atoms into superatoms and devising ways of determining reasonable force fields for the superatoms in a manner that retains essential macromolecular features relevant to the process under study but jettisons unnecessary details. In this work we systematically develop a coarse-graining scheme aimed at simulating uniaxial stress-strain behavior of polymers below their glass transition. The scheme involves a two step process of obtaining the coarse grained force field parameters above glass transition. This seems to be enough to obtain "faithful" stress-strain responses after quenching to below the glass transition temperature. We apply the scheme developed to a commercially important polymer polystyrene, derive its complete force field parameters and thus demonstrate the effectiveness of the technique.
18. On interfacial properties of tetrahydrofuran: Atomistic and coarse-grained models from molecular dynamics simulation
Garrido, J. M.; Algaba, J.; Míguez, J. M.; Mendiboure, B.; Moreno-Ventas Bravo, A. I.; Piñeiro, M. M.; Blas, F. J.
2016-04-01
We have determined the interfacial properties of tetrahydrofuran (THF) from direct simulation of the vapor-liquid interface. The molecules are modeled using six different molecular models, three of them based on the united-atom approach and the other three based on a coarse-grained (CG) approach. In the first case, THF is modeled using the transferable parameters potential functions approach proposed by Chandrasekhar and Jorgensen [J. Chem. Phys. 77, 5073 (1982)] and a new parametrization of the TraPPE force fields for cyclic alkanes and ethers [S. J. Keasler et al., J. Phys. Chem. B 115, 11234 (2012)]. In both cases, dispersive and coulombic intermolecular interactions are explicitly taken into account. In the second case, THF is modeled as a single sphere, a diatomic molecule, and a ring formed from three Mie monomers according to the SAFT-γ Mie top-down approach [V. Papaioannou et al., J. Chem. Phys. 140, 054107 (2014)]. Simulations were performed in the molecular dynamics canonical ensemble and the vapor-liquid surface tension is evaluated from the normal and tangential components of the pressure tensor along the simulation box. In addition to the surface tension, we have also obtained density profiles, coexistence densities, critical temperature, density, and pressure, and interfacial thickness as functions of temperature, paying special attention to the comparison between the estimations obtained from different models and literature experimental data. The simulation results obtained from the three CG models as described by the SAFT-γ Mie approach are able to predict accurately the vapor-liquid phase envelope of THF, in excellent agreement with estimations obtained from TraPPE model and experimental data in the whole range of coexistence. However, Chandrasekhar and Jorgensen model presents significant deviations from experimental results. We also compare the predictions for surface tension as obtained from simulation results for all the models with
19. Temperature-sensitive nanogels in the presence of salt: explicit coarse-grained simulations.
PubMed
Quesada-Pérez, Manuel; Ahualli, Silvia; Martín-Molina, Alberto
2014-09-28
In this work, coarse-grained simulations of two charged thermo-shrinking nanogels (with degrees of ionization of 0.125 and 0.250) in the presence of 1:1 and 3:1 electrolytes have been explicitly performed through the bead-spring model of polyelectrolyte. In a first set of simulations, salt concentrations for 1:1 and 3:1 electrolytes ranged from 1 to 100 mM and from 0.167 to 16.7 mM, respectively, whereas temperature remained fixed at a value for which hydrophobic forces were negligible in our case (288 K). The sizes of swollen nanogels are smaller when trivalent cations are present, but they do not change significantly in the range of concentrations of 3:1 electrolyte studied here. It should be also stressed that trivalent cations neutralize the nanogel charge more efficiently. According to these results the electrostatic repulsion plays an important role. In a second set of simulations, the temperature varied from 288 to 333 K to study the effect of salt on the thermal response when hydrophobic forces are not negligible. For the nanogels with the lowest degree of ionization, the behavior of the radius with increasing the temperature can be described by a sigmoid function, which shifts towards lower temperatures in the presence of salt. This shift is more clearly observed for trivalent cations, even at low concentrations. For the nanogels with the highest degree of ionization, the effect of additional electrolyte is also noticeable. In this case, hydrophobic forces are not the only responsible for their shrinkage in the presence of trivalent cations. The surface electrostatic potential and the concentration of salt cations inside the nanogel have been computed from simulations and a modified Poisson-Boltzmann (PB) cell model. The thermosensitivity in size have certain influence on the sensitivity of these properties to temperature changes. The rich behavior of the surface electrostatic potential and the uptake of salt cations are successfully predicted by the
20. Transferability of the coarse-grained potentials for trans-1,4-polybutadiene.
PubMed
Gao, Peiyuan; Guo, Hongxia
2015-12-21
In this paper, we evaluate the transferability of the coarse-grained (CG) force field (FF) of trans-1,4-polybutadiene which was built via a combined structure-based and thermodynamic quantity-based CG method at 413 K and 1 atm by systematically examining CG simulated structural and thermodynamic properties against the underlying atomistic simulation results at different temperatures. Interestingly, the derived CG force field exhibits good "state-point transferability" to some extent. For example, when applying this CG FF to the nearby state point (e.g., amorphous phase at 500 K), the resulting local conformation statistics, chain size, and local packing properties as well as density values for the CG models closely match the atomistic simulated data. When further applying this CG force field to the crystalline state at 300 K, the structural and thermodynamic properties of the crystalline phase formed for these CG and atomistic MD simulations still match within a certain level of accuracy. Furthermore, the CG torsion potential has a dual effect: for the amorphous state, the presence of an intramolecular energy barrier against rotation improves the capability of CG models to more precisely reproduce the structural properties, while in the crystalline state this CG torsion barrier suppresses the formation of the more fully stretched chain with a higher trans content. As a result, in the crystalline phase the CG model chains without torsion potentials possess a more stretched chain conformation, pack more efficiently, and have a higher crystallinity degree than its counterpart with CG torsion potentials as well as its underlying atomistic model. However, the dual effect of CG torsion potentials does not mean that we have to use different dihedral parameters to describe different state points. Both CG FFs, one with and another without torsion potentials, are able to represent the melt and the crystalline states. Overall, the phase and its structural consistency between
1. On interfacial properties of tetrahydrofuran: Atomistic and coarse-grained models from molecular dynamics simulation.
PubMed
Garrido, J M; Algaba, J; Míguez, J M; Mendiboure, B; Moreno-Ventas Bravo, A I; Piñeiro, M M; Blas, F J
2016-04-14
We have determined the interfacial properties of tetrahydrofuran (THF) from direct simulation of the vapor-liquid interface. The molecules are modeled using six different molecular models, three of them based on the united-atom approach and the other three based on a coarse-grained (CG) approach. In the first case, THF is modeled using the transferable parameters potential functions approach proposed by Chandrasekhar and Jorgensen [J. Chem. Phys. 77, 5073 (1982)] and a new parametrization of the TraPPE force fields for cyclic alkanes and ethers [S. J. Keasler et al., J. Phys. Chem. B 115, 11234 (2012)]. In both cases, dispersive and coulombic intermolecular interactions are explicitly taken into account. In the second case, THF is modeled as a single sphere, a diatomic molecule, and a ring formed from three Mie monomers according to the SAFT-γ Mie top-down approach [V. Papaioannou et al., J. Chem. Phys. 140, 054107 (2014)]. Simulations were performed in the molecular dynamics canonical ensemble and the vapor-liquid surface tension is evaluated from the normal and tangential components of the pressure tensor along the simulation box. In addition to the surface tension, we have also obtained density profiles, coexistence densities, critical temperature, density, and pressure, and interfacial thickness as functions of temperature, paying special attention to the comparison between the estimations obtained from different models and literature experimental data. The simulation results obtained from the three CG models as described by the SAFT-γ Mie approach are able to predict accurately the vapor-liquid phase envelope of THF, in excellent agreement with estimations obtained from TraPPE model and experimental data in the whole range of coexistence. However, Chandrasekhar and Jorgensen model presents significant deviations from experimental results. We also compare the predictions for surface tension as obtained from simulation results for all the models with
2. Derivation of free energy expressions for tube models from coarse-grained slip-link models.
PubMed
Steenbakkers, Rudi J A; Schieber, Jay D
2012-07-21
We present the free energy of a single-chain mean-field model for polymer melt dynamics, which uses a continuous (tube-like) approximation to the discrete entanglements with surrounding chains, but, in contrast to previous tube models, includes fluctuations in the number density of Kuhn steps along the primitive path and in the degree of entanglement. The free energy is obtained from that of the slip-link model with fluctuating entanglement positions [J. D. Schieber and K. Horio, J. Chem. Phys. 132, 074905 (2010)] by taking the continuous limit of (functions of) the discrete Kuhn-step numbers and end-to-end vectors of the strands between entanglements. This coarse-graining from a more-detailed level of description has the advantage that no ad hoc arguments need to be introduced. Moreover, the thermodynamic consistency of the slip-link model [J. D. Schieber, J. Non-Equilib. Thermodyn. 28, 179 (2003)] can be preserved. Fluctuations in the positions of entanglements lead to a harmonic bending term in the free energy of the continuous chain, similar to that derived by Read et al. [Macromolecules 41, 6843 (2008)] starting from a modified GLaMM model [R. S. Graham, A. E. Likhtman, T. C. B. McLeish, and S. T. Milner, J. Rheol. 47, 1171 (2003)]. If these fluctuations are set to zero, the free energy becomes purely Gaussian and corresponds to the continuous limit of the original slip-link model, with affinely moving entanglements [J. D. Schieber, J. Chem. Phys. 118, 5162 (2003)]. The free energy reduces to that of Read et al. under their assumptions of a homogeneous Kuhn-step number density and a constant degree of entanglement. Finally, we show how a transformation of the primitive-path coordinate can be applied to make the degree of entanglement an outcome of the model instead of a variable. In summary, this paper constitutes a first step towards a unified mathematical formulation of tube models. The next step will be to formulate the dynamics of the primitive
3. Derivation of free energy expressions for tube models from coarse-grained slip-link models
Steenbakkers, Rudi J. A.; Schieber, Jay D.
2012-07-01
We present the free energy of a single-chain mean-field model for polymer melt dynamics, which uses a continuous (tube-like) approximation to the discrete entanglements with surrounding chains, but, in contrast to previous tube models, includes fluctuations in the number density of Kuhn steps along the primitive path and in the degree of entanglement. The free energy is obtained from that of the slip-link model with fluctuating entanglement positions [J. D. Schieber and K. Horio, J. Chem. Phys. 132, 074905 (2010)], 10.1063/1.3314727 by taking the continuous limit of (functions of) the discrete Kuhn-step numbers and end-to-end vectors of the strands between entanglements. This coarse-graining from a more-detailed level of description has the advantage that no ad hoc arguments need to be introduced. Moreover, the thermodynamic consistency of the slip-link model [J. D. Schieber, J. Non-Equilib. Thermodyn. 28, 179 (2003)], 10.1515/JNETDY.2003.010 can be preserved. Fluctuations in the positions of entanglements lead to a harmonic bending term in the free energy of the continuous chain, similar to that derived by Read et al. [Macromolecules 41, 6843 (2008)], 10.1021/ma8009855 starting from a modified GLaMM model [R. S. Graham, A. E. Likhtman, T. C. B. McLeish, and S. T. Milner, J. Rheol. 47, 1171 (2003)], 10.1122/1.1595099. If these fluctuations are set to zero, the free energy becomes purely Gaussian and corresponds to the continuous limit of the original slip-link model, with affinely moving entanglements [J. D. Schieber, J. Chem. Phys. 118, 5162 (2003)], 10.1063/1.1553764. The free energy reduces to that of Read et al. under their assumptions of a homogeneous Kuhn-step number density and a constant degree of entanglement. Finally, we show how a transformation of the primitive-path coordinate can be applied to make the degree of entanglement an outcome of the model instead of a variable. In summary, this paper constitutes a first step towards a unified mathematical
4. Transferability of coarse-grained force field for nCB liquid crystal systems.
PubMed
Zhang, Jianguo; Guo, Hongxia
2014-05-01
In this paper, the transferability of the coarse-grained (CG) force field originally developed for the liquid crystal (LC) molecule 5CB ( Zhang et al. J. Phys. Chem. B 2012 , 116 , 2075 - 2089 ) was investigated by its homologues 6CB and 8CB molecules. Note that, to construct the 5CB CG force field, we combined the structure-based and thermodynamic quantities-based methods and at the same time attempted to use several fragment molecular systems to derive the CG nonbonded interaction parameters. The resultant 5CB CG force field exhibits a good transferability to some extent. For example, not only the experimental densities, the local packing of atom groups, and the antiparallel arrangements of nearest neighboring molecules, but also the unique LC mesophases as well as the nematic-isotropic phase transition temperatures of 6CB and 8CB were reproduced. Meanwhile, the limitations of this 5CB CG force field were also observed, such as the phase transition from nematic to smectic was postponed to the lower temperature and the resulting smectic phase structure is single-layer-like instead of partially interdigitated bilayer-like as observed in underlying atomistic model. Apparently, more attention should be paid when applying a CG force field to the state point which is quite different from which the force field is explicitly parametrized for. The origin of the above limitations can be potentially traced back to the inherent simplifications and some approximations often adopted in the creation process of CG force field, for example, choosing symmetric CG potentials which do not explicitly include electrostatic interactions and are parametrized by reproducing the target properties of the specific nematic 5CB phase at 300 K and 1 atm, as well as using soft nonbonded potential and excluding torsion barriers. Moreover, although by construction this CG force field could inevitably incorporate both thermodynamic and local structural information on the nematic 5CB phase, the
5. Temperature-sensitive nanogels in the presence of salt: explicit coarse-grained simulations.
PubMed
Quesada-Pérez, Manuel; Ahualli, Silvia; Martín-Molina, Alberto
2014-09-28
In this work, coarse-grained simulations of two charged thermo-shrinking nanogels (with degrees of ionization of 0.125 and 0.250) in the presence of 1:1 and 3:1 electrolytes have been explicitly performed through the bead-spring model of polyelectrolyte. In a first set of simulations, salt concentrations for 1:1 and 3:1 electrolytes ranged from 1 to 100 mM and from 0.167 to 16.7 mM, respectively, whereas temperature remained fixed at a value for which hydrophobic forces were negligible in our case (288 K). The sizes of swollen nanogels are smaller when trivalent cations are present, but they do not change significantly in the range of concentrations of 3:1 electrolyte studied here. It should be also stressed that trivalent cations neutralize the nanogel charge more efficiently. According to these results the electrostatic repulsion plays an important role. In a second set of simulations, the temperature varied from 288 to 333 K to study the effect of salt on the thermal response when hydrophobic forces are not negligible. For the nanogels with the lowest degree of ionization, the behavior of the radius with increasing the temperature can be described by a sigmoid function, which shifts towards lower temperatures in the presence of salt. This shift is more clearly observed for trivalent cations, even at low concentrations. For the nanogels with the highest degree of ionization, the effect of additional electrolyte is also noticeable. In this case, hydrophobic forces are not the only responsible for their shrinkage in the presence of trivalent cations. The surface electrostatic potential and the concentration of salt cations inside the nanogel have been computed from simulations and a modified Poisson-Boltzmann (PB) cell model. The thermosensitivity in size have certain influence on the sensitivity of these properties to temperature changes. The rich behavior of the surface electrostatic potential and the uptake of salt cations are successfully predicted by the
6. Coarse-grained deltaic sedimentation in the Miocene Cuyama strike-slip basin, California Coast Ranges
USGS Publications Warehouse
Alan, Bartow J.
1990-01-01
The Cuyama basin, located in the southern Coast Ranges of California southwest of the San Andreas fault, developed early in the history of the San Andreas transform system. The Miocene marine basin formed in a transtensional setting along a dextral strike-slip fault of the transform system following Oligocene non-marine basin formation in an extensional setting. The lower and middle Miocene Vaqueros Formation in the northwestern part of the basin, which represents the first of two transgressive-regressive cycles, is described here in terms of nine facies in two broad facies groups. The 400-m-thick Soda Lake Shale Member (of the Vaqueros) comprises deep-basin and starved-basin facies. A thin transgressive facies occurs locally at the base of the formation. The overlying Painted Rock Sandstone Member (of the Vaqueros), which is more than 2200 m thick and consists mostly of coarse-grained sandstone and pebbly sandstone, constitutes a delta complex of prodelta, slope channel, delta front, tide-influenced distributary channel, interdistributary bay, and fluvial channel facies. The basinal depositional system consisted of turbidite mud and sand, and hemipelagic and pelagic sediments of the basinal facies deposited in a rapidly subsiding basin. The delta depositional system consisted of the delta complex facies that prograded into the deep basin and had a steep prodelta slope that extended to bathyal depths. The delta is inferred to be a mixed fluvial-wave-dominated fan delta, analogous in its delta-front morphology and processes to a fjord delta, in which coarse sediment delivered to the delta front by braided streams was transported down the prodelta slope into deep water by sediment gravity flows. Transgression and rapid deepening of the basin in the early Miocene coincided with rapid tectonic subsidence. Deepening culminated with deposition of a starved-basin facies or condensed section at the time of maximum transgression, which was followed by the beginning of a
7. Concurrent Multiscale Simulation at Finite Temperature: Coarse-Grained Molecular Dynamics
SciTech Connect
Rudd, R E
2004-01-22
With the advent of nanotechnology, predictive simulations of nanoscale systems have become in great demand. In some cases nanoscale systems can be simulated directly at the level of atoms. The atomistic techniques used range from models based on a quantum mechanical treatment of the electronic bonds to those based on more empirical descriptions of the interatomic forces. In many cases, however, even nanoscale systems are too big for a purely atomistic approach, typically because the nanoscale device is coupled to its surroundings, and it is necessary to simulate the entire system comprising billions of atoms. A well-known example is the growth of nanoscale epitaxial quantum dots in which the size, shape and location of the dot is affected by the elastic strain developed in a large volume of the substrate as well as the local atomic bonding. The natural solution is to model the surroundings with a more coarse-grained description, suitable for the intrinsically longer length scale. The challenge then is to develop the computational methodology suitable for this kind of concurrent multiscale modeling, one in which the simulated length scale can be changed smoothly and seamlessly from one region of the simulation to another while maintaining the fidelity of the relevant mechanics, dynamics and thermodynamics. The realization that Nature has different relevant length scales goes back at least as far as Democritus. Some 24 centuries ago he put forward the idea that solid matter is comprised ultimately at small scales by a fundamental constituent that he termed an atom. Implicit in his philosophy was the idea that an understanding of the atom would lead to a more robust understanding of the macroscopic world around us. In the intervening period, of course, not only has the science of this atomistic picture been put on a sound footing through the inventions of chemistry, the discovery of the nucleus and the development of quantum mechanics and modern condensed matter
8. Temperature-sensitive nanogels in the presence of salt: Explicit coarse-grained simulations
Quesada-Pérez, Manuel; Ahualli, Silvia; Martín-Molina, Alberto
2014-09-01
In this work, coarse-grained simulations of two charged thermo-shrinking nanogels (with degrees of ionization of 0.125 and 0.250) in the presence of 1:1 and 3:1 electrolytes have been explicitly performed through the bead-spring model of polyelectrolyte. In a first set of simulations, salt concentrations for 1:1 and 3:1 electrolytes ranged from 1 to 100 mM and from 0.167 to 16.7 mM, respectively, whereas temperature remained fixed at a value for which hydrophobic forces were negligible in our case (288 K). The sizes of swollen nanogels are smaller when trivalent cations are present, but they do not change significantly in the range of concentrations of 3:1 electrolyte studied here. It should be also stressed that trivalent cations neutralize the nanogel charge more efficiently. According to these results the electrostatic repulsion plays an important role. In a second set of simulations, the temperature varied from 288 to 333 K to study the effect of salt on the thermal response when hydrophobic forces are not negligible. For the nanogels with the lowest degree of ionization, the behavior of the radius with increasing the temperature can be described by a sigmoid function, which shifts towards lower temperatures in the presence of salt. This shift is more clearly observed for trivalent cations, even at low concentrations. For the nanogels with the highest degree of ionization, the effect of additional electrolyte is also noticeable. In this case, hydrophobic forces are not the only responsible for their shrinkage in the presence of trivalent cations. The surface electrostatic potential and the concentration of salt cations inside the nanogel have been computed from simulations and a modified Poisson-Boltzmann (PB) cell model. The thermosensitivity in size have certain influence on the sensitivity of these properties to temperature changes. The rich behavior of the surface electrostatic potential and the uptake of salt cations are successfully predicted by the
9. Transferability of the coarse-grained potentials for trans-1,4-polybutadiene.
PubMed
Gao, Peiyuan; Guo, Hongxia
2015-12-21
In this paper, we evaluate the transferability of the coarse-grained (CG) force field (FF) of trans-1,4-polybutadiene which was built via a combined structure-based and thermodynamic quantity-based CG method at 413 K and 1 atm by systematically examining CG simulated structural and thermodynamic properties against the underlying atomistic simulation results at different temperatures. Interestingly, the derived CG force field exhibits good "state-point transferability" to some extent. For example, when applying this CG FF to the nearby state point (e.g., amorphous phase at 500 K), the resulting local conformation statistics, chain size, and local packing properties as well as density values for the CG models closely match the atomistic simulated data. When further applying this CG force field to the crystalline state at 300 K, the structural and thermodynamic properties of the crystalline phase formed for these CG and atomistic MD simulations still match within a certain level of accuracy. Furthermore, the CG torsion potential has a dual effect: for the amorphous state, the presence of an intramolecular energy barrier against rotation improves the capability of CG models to more precisely reproduce the structural properties, while in the crystalline state this CG torsion barrier suppresses the formation of the more fully stretched chain with a higher trans content. As a result, in the crystalline phase the CG model chains without torsion potentials possess a more stretched chain conformation, pack more efficiently, and have a higher crystallinity degree than its counterpart with CG torsion potentials as well as its underlying atomistic model. However, the dual effect of CG torsion potentials does not mean that we have to use different dihedral parameters to describe different state points. Both CG FFs, one with and another without torsion potentials, are able to represent the melt and the crystalline states. Overall, the phase and its structural consistency between
10. Transferability of coarse-grained force field for nCB liquid crystal systems.
PubMed
Zhang, Jianguo; Guo, Hongxia
2014-05-01
In this paper, the transferability of the coarse-grained (CG) force field originally developed for the liquid crystal (LC) molecule 5CB ( Zhang et al. J. Phys. Chem. B 2012 , 116 , 2075 - 2089 ) was investigated by its homologues 6CB and 8CB molecules. Note that, to construct the 5CB CG force field, we combined the structure-based and thermodynamic quantities-based methods and at the same time attempted to use several fragment molecular systems to derive the CG nonbonded interaction parameters. The resultant 5CB CG force field exhibits a good transferability to some extent. For example, not only the experimental densities, the local packing of atom groups, and the antiparallel arrangements of nearest neighboring molecules, but also the unique LC mesophases as well as the nematic-isotropic phase transition temperatures of 6CB and 8CB were reproduced. Meanwhile, the limitations of this 5CB CG force field were also observed, such as the phase transition from nematic to smectic was postponed to the lower temperature and the resulting smectic phase structure is single-layer-like instead of partially interdigitated bilayer-like as observed in underlying atomistic model. Apparently, more attention should be paid when applying a CG force field to the state point which is quite different from which the force field is explicitly parametrized for. The origin of the above limitations can be potentially traced back to the inherent simplifications and some approximations often adopted in the creation process of CG force field, for example, choosing symmetric CG potentials which do not explicitly include electrostatic interactions and are parametrized by reproducing the target properties of the specific nematic 5CB phase at 300 K and 1 atm, as well as using soft nonbonded potential and excluding torsion barriers. Moreover, although by construction this CG force field could inevitably incorporate both thermodynamic and local structural information on the nematic 5CB phase, the
11. Coarse-Grained Molecular Dynamics Study of the Curing and Properties of Highly Cross-Linked Epoxy Polymers.
PubMed
Aramoon, Amin; Breitzman, Timothy D; Woodward, Christopher; El-Awady, Jaafar A
2016-09-01
In this work, a coarse-grained model is developed for highly cross-linked bisphenol A diglycidyl ether epoxy resin with diaminobutane hardener. In this model, all conformationally relevant coarse-grained degrees of freedom are accounted for by sampling over the free-energy surfaces of the atomic structures using quantum mechanical simulations. The interaction potentials between nonbonded coarse-grained particles are optimized to accurately predict the experimentally measured density and glass-transition temperature of the system. In addition, a new curing algorithm is also developed to model the creation of highly cross-linked epoxy networks. In this algorithm, to create a highly cross-linked network, the reactants are redistributed from regions with an excessive number of reactive molecules to regions with a lower number of reactants to increase the chances of cross-linking. This new algorithm also dynamically controls the rate of cross-linking at each local region to ensure uniformity of the resulting network. The curing simulation conducted using this algorithm is able to develop polymeric networks having a higher average degree of cross-linking, which is more uniform throughout the simulation cell as compared to that in the networks cured using other curing algorithms. The predicted gel point from the current curing algorithm is in the acceptable theoretical and experimental range of measured values. Also, the resulting cross-linked microstructure shows a volume shrinkage of 5%, which is close to the experimentally measured volume shrinkage of the cured epoxy. Finally, the thermal expansion coefficients of materials in the glassy and rubbery states show good agreement with the experimental values.
12. Coarse-Grained Molecular Dynamics Study of the Curing and Properties of Highly Cross-Linked Epoxy Polymers.
PubMed
Aramoon, Amin; Breitzman, Timothy D; Woodward, Christopher; El-Awady, Jaafar A
2016-09-01
In this work, a coarse-grained model is developed for highly cross-linked bisphenol A diglycidyl ether epoxy resin with diaminobutane hardener. In this model, all conformationally relevant coarse-grained degrees of freedom are accounted for by sampling over the free-energy surfaces of the atomic structures using quantum mechanical simulations. The interaction potentials between nonbonded coarse-grained particles are optimized to accurately predict the experimentally measured density and glass-transition temperature of the system. In addition, a new curing algorithm is also developed to model the creation of highly cross-linked epoxy networks. In this algorithm, to create a highly cross-linked network, the reactants are redistributed from regions with an excessive number of reactive molecules to regions with a lower number of reactants to increase the chances of cross-linking. This new algorithm also dynamically controls the rate of cross-linking at each local region to ensure uniformity of the resulting network. The curing simulation conducted using this algorithm is able to develop polymeric networks having a higher average degree of cross-linking, which is more uniform throughout the simulation cell as compared to that in the networks cured using other curing algorithms. The predicted gel point from the current curing algorithm is in the acceptable theoretical and experimental range of measured values. Also, the resulting cross-linked microstructure shows a volume shrinkage of 5%, which is close to the experimentally measured volume shrinkage of the cured epoxy. Finally, the thermal expansion coefficients of materials in the glassy and rubbery states show good agreement with the experimental values. PMID:27504803
13. Accurate coarse-grained models for mixtures of colloids and linear polymers under good-solvent conditions
SciTech Connect
D’Adamo, Giuseppe; Pelissetto, Andrea; Pierleoni, Carlo
2014-12-28
A coarse-graining strategy, previously developed for polymer solutions, is extended here to mixtures of linear polymers and hard-sphere colloids. In this approach, groups of monomers are mapped onto a single pseudoatom (a blob) and the effective blob-blob interactions are obtained by requiring the model to reproduce some large-scale structural properties in the zero-density limit. We show that an accurate parametrization of the polymer-colloid interactions is obtained by simply introducing pair potentials between blobs and colloids. For the coarse-grained (CG) model in which polymers are modelled as four-blob chains (tetramers), the pair potentials are determined by means of the iterative Boltzmann inversion scheme, taking full-monomer (FM) pair correlation functions at zero-density as targets. For a larger number n of blobs, pair potentials are determined by using a simple transferability assumption based on the polymer self-similarity. We validate the model by comparing its predictions with full-monomer results for the interfacial properties of polymer solutions in the presence of a single colloid and for thermodynamic and structural properties in the homogeneous phase at finite polymer and colloid density. The tetramer model is quite accurate for q ≲ 1 (q=R{sup ^}{sub g}/R{sub c}, where R{sup ^}{sub g} is the zero-density polymer radius of gyration and R{sub c} is the colloid radius) and reasonably good also for q = 2. For q = 2, an accurate coarse-grained description is obtained by using the n = 10 blob model. We also compare our results with those obtained by using single-blob models with state-dependent potentials.
14. Conformational Properties of Sodium Polystyrenesulfonate in Water: Insights from a Coarse-Grained Model with Explicit Solvent.
PubMed
Mantha, Sriteja; Yethiraj, Arun
2015-08-27
Polymer solutions present a significant computational challenge because chemical realism on small length scales can be important, but the polymer molecules are very large. In polyelectrolyte solutions, there is often the additional complexity that the molecules consist of hydrophobic and charged groups, which makes an accurate treatment of the solvent, water, crucial. One route to achieve this balance is through coarse-grained models where several atoms on a monomer are grouped into one interaction site. In this work, we develop a coarse grained (CG) model for sodium polystyrenesulfonate (NaPSS) in water using a methodology consistent with the MARTINI coarse-graining philosophy, where four heavy atoms are grouped into one CG site. We consider two models for water: polarizable MARTINI (POL) and big multipole water (BMW). In each case, interaction parameters for the polymer sites are obtained by matching the potential of mean force between two monomers to results of atomistic simulations. The force field based on the POL water provides a more reasonable description of polymer properties than that based on the BMW water. We study the properties of single chains using the POL force field. Fully sulfonated chains are rodlike (i.e., the root-mean-square radius of gyration, Rg, scales linearly with degree of polymerization, N). When the fraction of sulfonation, f, is 0.25 or less, the chain collapses into a cylindrical globule. For f = 0.5, pearl-necklace conformations are observed when every second monomer is sulfonated. The lifetime of a counterion around a polymer is on the order of 100 ps, suggesting that there is no counterion condensation. The model is computationally feasible and should allow one to study the effect of local chemistry on the properties of polymers in aqueous solution. PMID:26047770
15. Coarse Grain Progradation in a Foreland basin: Application of Detrital Zircon Double Dating to Cenozoic Stratigraphy, Eastern Cordillera, Colombia.
Odoh, S.; Saylor, J. E.; Higuera-Diaz, C.; Lapen, T. J.; Copeland, P.
2015-12-01
Progradation of coarse clastic material into distal foreland basins has been attributed to both 1) enhanced sediment production during rapid tectonic exhumation and 2) sediment reworking during tectonic quiescence. The Floresta and Medina basins in the Eastern Cordillera record deposition of alternating coarse- and fine-grained clastic strata in medial and distal (respectively) Cenozoic foreland basins. The Medina Basin records the continued eastward progradation of the deformation front in the Neogene. We use detrital zircon U-Pb (ZPb) and (U-Th)/He (ZHe) analyses from the Paleogene Floresta Basin and the entire Cenozoic Medina Basin record to evaluate the effects of episodic thrust-belt exhumation and wide-spread deposition of coarse-grained sediments in the adjacent foreland basin. Both ZPb and ZHe systems are applied to individual grains (double dating) to constrain source area and up-section variations in exhumation rates. Changes in exhumation rate or introduction of new sediment sources are recorded as changes in lag time (ZHe age - depositional age). Analysis of 6 samples from the Floresta Basin shows a decrease in lag time during deposition of the coarse-grained middle Eocene Picacho Formation and upper Paleocene Socha Sandstone suggesting that Paleogene deposition of coarse-grained intervals in this medial location corresponds to an increase in exhumation rate. However, initial results from the Medina basin are less clear as there is evidence for Paleocene volcanic input but no clear evidence for thrust-belt related sediment until the Oligocene-early Miocene. We interpret the evidence for different sediment sources for Eocene strata in the axial Eastern Cordillera (Floresta) versus the Eastern foothills (Medina) as indicative of separation of these two regions by an emergent forebulge. Exhumation rate and granularity appear to be inversely correlated in post-Oligocene strata, though confirmation of initial interpretations awaits larger samples sizes
16. Coarse-grained molecular dynamics simulation of the void growth process in the block structure of semicrystalline polymers
Higuchi, Yuji; Kubo, Momoji
2016-06-01
We study fracture processes of amorphous and semicrystalline polymers with a coarse-grained molecular dynamics simulation. In the amorphous state, the stress caused by strain mainly arises from the loss of the attractive interaction in the voids. However, in semicrystalline polymers, the elongation of bonding is the dominant factor and it causes much more stress than that in an amorphous state. This is because growth of the voids is prevented by the amorphous regions and it is difficult to relax the folded polymers.
17. Optical dating of tidal flat sediments in the western coast of the Korean Peninsula: A comparison between fine- and coarse-grained quartz
Kim, J.; Chang, T.; Yi, S.; Hong, S.
2012-12-01
We tested the applicability of optically stimulated luminescence (OSL) dating to fine- and coarse-grained quartz from the western coastal sediments of the Korean Peninsula. Twenty six samples were collected from 43-m-long core sediments, which contain two tidal deposits stratigraphically separated by a yellow, semi-consolidated mud layer and a gravel layer. A single aliquot regenerative dose (SAR) procedure was applied to chemically purified quartz grains of different grain sizes (4-11 and 90-212 μm diameter). The fine grain (4-11μm) OSL shows much higher saturation characteristic doses than those of the coarse grain (90-212 μm) OSL. The growth curves of the fine grain OSL show linear growth with dose up to ~800 Gy, whereas the those of the coarse grain OSL show an early saturated growth curve pattern (below 300 Gy). The OSL signal from the fine grain shows a quartz-dominated signal. On the other hand, OSL signals from coarse grain still contain a contribution from feldspars even after repeated chemical treatments. The De values are in agreement between the fine- and coarse-grained OSL in the upper part (0-15 m depth), but those of the lower part (>15 m) sediments are not. In the lower part, the De values of the fine grain are much higher (>400 Gy) than those from the coarse grain (<250 Gy). The ages obtained using fine grain are consistent with those from coarse grain for the upper part, but for the lower core samples ages based on fine grain OSL become progressively larger than those based on coarse grain. The fine grain ages are considered to be more accurate than the coarse grain ages, because they are not affected by signal saturation in this age range. Also, feldspar contamination may give rise to underestimation of the ages from the coarse grain OSL. Our results indicate that the ages obtained using fine-grained quartz can be old back to the Eemian. The major parts containing two tidal deposits have been deposited during the Holocene and MIS 5, with a
18. Structural and Energetic Characterization of the Ankyrin Repeat Protein Family
PubMed Central
Parra, R. Gonzalo; Espada, Rocío; Verstraete, Nina; Ferreiro, Diego U.
2015-01-01
Ankyrin repeat containing proteins are one of the most abundant solenoid folds. Usually implicated in specific protein-protein interactions, these proteins are readily amenable for design, with promising biotechnological and biomedical applications. Studying repeat protein families presents technical challenges due to the high sequence divergence among the repeating units. We developed and applied a systematic method to consistently identify and annotate the structural repetitions over the members of the complete Ankyrin Repeat Protein Family, with increased sensitivity over previous studies. We statistically characterized the number of repeats, the folding of the repeat-arrays, their structural variations, insertions and deletions. An energetic analysis of the local frustration patterns reveal the basic features underlying fold stability and its relation to the functional binding regions. We found a strong linear correlation between the conservation of the energetic features in the repeat arrays and their sequence variations, and discuss new insights into the organization and function of these ubiquitous proteins. PMID:26691182
19. Non-Markovian coarse-grained modeling of polymeric fluids based on the Mori-Zwanzig formalism
Li, Zhen; Bian, Xin; Li, Xiantao; Karniadakis, George
The Mori-Zwanzig formalism for coarse-graining a complex dynamical system typically introduces memory effects. The Markovian assumption of delta-correlated fluctuating forces is often employed to simplify the formulation of coarse-grained (CG) models and numerical implementations. However, when the time scales of a system are not clearly separated, the memory effects become strong and the Markovian assumption becomes inaccurate. To this end, we incorporate memory effects into CG modeling by preserving non-Markovian interactions between CG variables based on the Mori-Zwanzig formalism. For a specific example, molecular dynamics (MD) simulations of star polymer melts are performed while the corresponding CG system is defined by grouping many bonded atoms into single clusters. Then, the effective interactions between CG clusters as well as the memory kernel are obtained from the MD simulations. The constructed CG force field with a memory kernel leads to a non-Markovian dissipative particle dynamics (NM-DPD). Quantitative comparisons on both static and dynamic properties between the CG models with Markovian and non-Markovian approximations will be presented. Supported by the DOE Center on Mathematics for Mesoscopic Modeling of Materials (CM4) and an INCITE grant.
20. Canonical ensemble simulation of biopolymers using a coarse-grained articulated generalized divide-and-conquer scheme
2013-03-01
In this paper, a scheme for the canonical ensemble simulation of the coarse-grained articulated polymers is discussed. In this coarse-graining strategy, different subdomains of the system are considered as rigid and/or flexible bodies connected to each other via kinematic joints instead of stiff, but elastic bonds. Herein, the temperature of the simulation is controlled by a Nosé-Hoover thermostat. The dynamics of this feedback control system in the context of multibody dynamics may be represented and solved using traditional methods with computational complexity of O(n3) where n denotes the number of degrees of freedom of the system. In this paper, we extend the divide-and-conquer algorithm (DCA), and apply it to constant temperature molecular simulations. The DCA in its original form uses spatial forces to formulate the equations of motion. The Generalized-DCA applied here properly accommodates the thermostat generalized forces (from the thermostat), which control the temperature of the simulation, in the equations of motion. This algorithm can be implemented in serial and parallel with computational complexity of O(n) and O(logn), respectively.
1. A coarse-grained model with implicit salt for RNAs: Predicting 3D structure, stability and salt effect
SciTech Connect
Shi, Ya-Zhou; Wang, Feng-Hua; Wu, Yuan-Yan; Tan, Zhi-Jie
2014-09-14
To bridge the gap between the sequences and 3-dimensional (3D) structures of RNAs, some computational models have been proposed for predicting RNA 3D structures. However, the existed models seldom consider the conditions departing from the room/body temperature and high salt (1M NaCl), and thus generally hardly predict the thermodynamics and salt effect. In this study, we propose a coarse-grained model with implicit salt for RNAs to predict 3D structures, stability, and salt effect. Combined with Monte Carlo simulated annealing algorithm and a coarse-grained force field, the model folds 46 tested RNAs (≤45 nt) including pseudoknots into their native-like structures from their sequences, with an overall mean RMSD of 3.5 Å and an overall minimum RMSD of 1.9 Å from the experimental structures. For 30 RNA hairpins, the present model also gives the reliable predictions for the stability and salt effect with the mean deviation ∼ 1.0 °C of melting temperatures, as compared with the extensive experimental data. In addition, the model could provide the ensemble of possible 3D structures for a short RNA at a given temperature/salt condition.
2. Energy, centrality, and momentum dependence of dielectron production at collider energies in a coarse-grained transport approach
Endres, Stephan; van Hees, Hendrik; Bleicher, Marcus
2016-08-01
Dilepton production in heavy-ion collisions at collider energies—i.e., for the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC)—is studied within an approach that uses coarse-grained transport simulations to calculate thermal dilepton emission applying in-medium spectral functions from hadronic many-body theory and partonic production rates based on lattice calculations. The microscopic output from the Ultrarelativistic Quantum Molecular Dynamics (UrQMD) model is hereby put on a grid of space-time cells, which makes it possible to extract the local temperature and chemical potential in each cell via an equation of state. The resulting dilepton spectra are in good agreement with the experimental results for the range of energies available at RHIC, √{sN N}=19.6 -200 GeV . The comparison of the data with the outcome from the coarse-grained UrQMD simulations shows that the newest measurements by the PHENIX and STAR Collaborations are consistent and that the low-mass spectra can be described by a cocktail of hadronic decay contributions together with thermal emission from broadened vector-meson spectral functions and from the quark-gluon plasma phase. Predictions for dilepton results at LHC energies show no significant change of the spectra as compared to RHIC, but a higher fraction of thermal contribution and harder slopes of the transverse-momentum distributions owing to the higher temperatures and flow obtained.
3. A coarse-grained biophysical model of sequence evolution and the population size dependence of the speciation rate
PubMed Central
Khatri, Bhavin S.; Goldstein, Richard A.
2015-01-01
Speciation is fundamental to understanding the huge diversity of life on Earth. Although still controversial, empirical evidence suggests that the rate of speciation is larger for smaller populations. Here, we explore a biophysical model of speciation by developing a simple coarse-grained theory of transcription factor-DNA binding and how their co-evolution in two geographically isolated lineages leads to incompatibilities. To develop a tractable analytical theory, we derive a Smoluchowski equation for the dynamics of binding energy evolution that accounts for the fact that natural selection acts on phenotypes, but variation arises from mutations in sequences; the Smoluchowski equation includes selection due to both gradients in fitness and gradients in sequence entropy, which is the logarithm of the number of sequences that correspond to a particular binding energy. This simple consideration predicts that smaller populations develop incompatibilities more quickly in the weak mutation regime; this trend arises as sequence entropy poises smaller populations closer to incompatible regions of phenotype space. These results suggest a generic coarse-grained approach to evolutionary stochastic dynamics, allowing realistic modelling at the phenotypic level. PMID:25936759
4. Coarse-grained simulations of transitions in the E2-to-E1 conformations for Ca ATPase (SERCA) show entropy-enthalpy compensation.
PubMed
Nagarajan, Anu; Andersen, Jens Peter; Woolf, Thomas B
2012-09-28
SERCA is a membrane transport protein that has been extensively studied. There are a large number of highly resolved X-ray structures and several hundred mutations that have been characterized functionally. Despite this, the molecular details of the catalytic cycle, a cycle that includes large conformational changes, is not fully understood. In this computational study, we provide molecular dynamics descriptions of conformational changes during the E2→E1 transitions. The motivating point for these calculations was a series of insertion mutants in the A-M3 linker region that led to significant shifts in measured rates between the E2 and E1 states, as shown by experimental characterization. Using coarse-grained dynamic importance sampling within the context of a population shift framework, we sample on the intermediates along the transition pathway to address the mechanism for the conformational changes and the effects of the insertion mutations on the kinetics of the transition. The calculations define an approximation for the relative changes in entropy and enthalpy along the transition. These are found to be important for understanding the experimentally observed differences in rates. In particular, the interactions between cytoplasmic domains, water interactions, and the shifts in protein degrees of freedom with the insertion mutations show mutual compensation for the E2→E1 transitions in wild-type and mutant systems.
5. Energetics of hydrogen bonding in proteins: a model compound study.
PubMed Central
Habermann, S. M.; Murphy, K. P.
1996-01-01
Differences in the energetics of amide-amide and amide-hydroxyl hydrogen bonds in proteins have been explored from the effect of hydroxyl groups on the structure and dissolution energetics of a series of crystalline cyclic dipeptides. The calorimetrically determined energetics are interpreted in light of the crystal structures of the studied compounds. Our results indicate that the amide-amide and amide-hydroxyl hydrogen bonds both provide considerable enthalpic stability, but that the amide-amide hydrogen bond is about twice that of the amide-hydroxyl. Additionally, the interaction of the hydroxyl group with water is seen most readily in its contributions to entropy and heat capacity changes. Surprisingly, the hydroxyl group shows weakly hydrophobic behavior in terms of these contributions. These results can be used to understand the effects of mutations on the stability of globular proteins. PMID:8819156
6. Conformational Changes in the Epidermal Growth Factor Receptor: Role of the Transmembrane Domain Investigated by Coarse-Grained MetaDynamics Free Energy Calculations
PubMed Central
2016-01-01
The epidermal growth factor receptor (EGFR) is a dimeric membrane protein that regulates key aspects of cellular function. Activation of the EGFR is linked to changes in the conformation of the transmembrane (TM) domain, brought about by changes in interactions of the TM helices of the membrane lipid bilayer. Using an advanced computational approach that combines Coarse-Grained molecular dynamics and well-tempered MetaDynamics (CG-MetaD), we characterize the large-scale motions of the TM helices, simulating multiple association and dissociation events between the helices in membrane, thus leading to a free energy landscape of the dimerization process. The lowest energy state of the TM domain is a right-handed dimer structure in which the TM helices interact through the N-terminal small-X3-small sequence motif. In addition to this state, which is thought to correspond to the active form of the receptor, we have identified further low-energy states that allow us to integrate with a high level of detail a range of previous experimental observations. These conformations may lead to the active state via two possible activation pathways, which involve pivoting and rotational motions of the helices, respectively. Molecular dynamics also reveals correlation between the conformational changes of the TM domains and of the intracellular juxtamembrane domains, paving the way for a comprehensive understanding of EGFR signaling at the cell membrane. PMID:27459426
7. Ion permeation in the NanC porin from Escherichia coli: free energy calculations along pathways identified by coarse-grain simulations.
PubMed
Dreyer, Jens; Strodel, Paul; Ippoliti, Emiliano; Finnerty, Justin; Eisenberg, Bob; Carloni, Paolo
2013-10-31
Using the X-ray structure of a recently discovered bacterial protein, the N-acetylneuraminic acid-inducible channel (NanC), we investigate computationally K(+) and Cl(-) ions' permeation. We identify ion permeation pathways that are likely to be populated using coarse-grain Monte Carlo simulations. Next, we use these pathways as reaction coordinates for umbrella sampling-based free energy simulations. We find distinct tubelike pathways connecting specific binding sites for K(+) and, more pronounced, for Cl(-) ions. Both ions permeate the porin preserving almost all of their first hydration shell. The calculated free energy barriers are G(#) ≈ 4 kJ/mol and G(#) ≈ 8 kJ/mol for Cl(-) and K(+), respectively. Within the approximations associated with these values, discussed in detail in this work, we suggest that the porin is slightly selective for Cl(-) versus K(+). Our suggestion is consistent with the experimentally observed weak Cl(-) over K(+) selectivity. A rationale for the latter is suggested by a comparison with previous calculations on strongly anion selective porins.
8. An experimentally-informed coarse-grained 3-Site-Per-Nucleotide model of DNA: structure, thermodynamics, and dynamics of hybridization.
PubMed
Hinckley, Daniel M; Freeman, Gordon S; Whitmer, Jonathan K; de Pablo, Juan J
2013-10-14
A new 3-Site-Per-Nucleotide coarse-grained model for DNA is presented. The model includes anisotropic potentials between bases involved in base stacking and base pair interactions that enable the description of relevant structural properties, including the major and minor grooves. In an improvement over available coarse-grained models, the correct persistence length is recovered for both ssDNA and dsDNA, allowing for simulation of non-canonical structures such as hairpins. DNA melting temperatures, measured for duplexes and hairpins by integrating over free energy surfaces generated using metadynamics simulations, are shown to be in quantitative agreement with experiment for a variety of sequences and conditions. Hybridization rate constants, calculated using forward-flux sampling, are also shown to be in good agreement with experiment. The coarse-grained model presented here is suitable for use in biological and engineering applications, including nucleosome positioning and DNA-templated engineering. PMID:24116642
9. A stochastic thermostat algorithm for coarse-grained thermomechanical modeling of large-scale soft matters: Theory and application to microfilaments
SciTech Connect
Li, Tong; Gu, YuanTong
2014-04-15
As all-atom molecular dynamics method is limited by its enormous computational cost, various coarse-grained strategies have been developed to extend the length scale of soft matters in the modeling of mechanical behaviors. However, the classical thermostat algorithm in highly coarse-grained molecular dynamics method would underestimate the thermodynamic behaviors of soft matters (e.g. microfilaments in cells), which can weaken the ability of materials to overcome local energy traps in granular modeling. Based on all-atom molecular dynamics modeling of microfilament fragments (G-actin clusters), a new stochastic thermostat algorithm is developed to retain the representation of thermodynamic properties of microfilaments at extra coarse-grained level. The accuracy of this stochastic thermostat algorithm is validated by all-atom MD simulation. This new stochastic thermostat algorithm provides an efficient way to investigate the thermomechanical properties of large-scale soft matters.
10. A stochastic thermostat algorithm for coarse-grained thermomechanical modeling of large-scale soft matters: Theory and application to microfilaments
Li, Tong; Gu, YuanTong
2014-04-01
As all-atom molecular dynamics method is limited by its enormous computational cost, various coarse-grained strategies have been developed to extend the length scale of soft matters in the modeling of mechanical behaviors. However, the classical thermostat algorithm in highly coarse-grained molecular dynamics method would underestimate the thermodynamic behaviors of soft matters (e.g. microfilaments in cells), which can weaken the ability of materials to overcome local energy traps in granular modeling. Based on all-atom molecular dynamics modeling of microfilament fragments (G-actin clusters), a new stochastic thermostat algorithm is developed to retain the representation of thermodynamic properties of microfilaments at extra coarse-grained level. The accuracy of this stochastic thermostat algorithm is validated by all-atom MD simulation. This new stochastic thermostat algorithm provides an efficient way to investigate the thermomechanical properties of large-scale soft matters.
11. Coarse-grained molecular dynamics studies of the translocation mechanism of polyarginines across asymmetric membrane under tension
PubMed Central
He, XiaoCong; Lin, Min; Sha, BaoYong; Feng, ShangSheng; Shi, XingHua; Qu, ZhiGuo; Xu, Feng
2015-01-01
Understanding interactions between cell-penetrating peptides and biomembrane under tension can help improve drug delivery and elucidate mechanisms underlying fundamental cellular events. As far as the effect of membrane tension on translocation, it is generally thought that tension should disorder the membrane structure and weaken its strength, thereby facilitating penetration. However, our coarse-grained molecular dynamics simulation results showed that membrane tension can restrain polyarginine translocation across the asymmetric membrane and that this effect increases with increasing membrane tension. We also analyzed the structural properties and lipid topology of the tensed membrane to explain the phenomena. Simulation results provide important molecular information on the potential translocation mechanism of peptides across the asymmetric membrane under tension as well as new insights in drug and gene delivery. PMID:26235300
12. Arsenic contamination of coarse-grained and nanostructured nitinol surfaces induced by chemical treatment in hydrofluoric acid.
PubMed
Korotin, D M; Bartkowski, S; Kurmaev, E Z; Borchers, C; Müller, M; Neumann, M; Gunderov, D V; Valiev, R Z; Cholakh, S O
2012-10-01
XPS measurements of coarse-grained and nanostructured nitinol (Ni(50.2)Ti(49.8)) before and after chemical treatment in hydrofluoric acid (40% HF, 1 min) are presented. The nanostructured state, providing the excellent mechanical properties of nitinol, is achieved by severe plastic deformation. The near-surface layers of nitinol were studied by XPS depth profiling. According to the obtained results, a chemical treatment in hydrofluoric acid reduces the thickness of the protective TiO(2) oxide layer and induces a nickel release from the nitinol surface and an arsenic contamination, and can therefore not be recommended as conditioning to increase the roughness of NiTi-implants. A detailed evaluation of the resulting toxicological risks is given.
13. Dissipative Particle Dynamics Simulations for Phospholipid Membranes Based on a Four-To-One Coarse-Grained Mapping Scheme.
PubMed
Li, Xiaoxu; Gao, Lianghui; Fang, Weihai
2016-01-01
In this article, a new set of parameters compatible with the dissipative particle dynamics (DPD) force field is developed for phospholipids. The coarse-grained (CG) models of these molecules are constructed by mapping four heavy atoms and their attached hydrogen atoms to one bead. The beads are divided into types distinguished by charge type, polarizability, and hydrogen-bonding capacity. First, we derive the relationship between the DPD repulsive force and Flory-Huggins χ-parameters based on this four-to-one CG mapping scheme. Then, we optimize the DPD force parameters for phospholipids. The feasibility of this model is demonstrated by simulating the structural and thermodynamic properties of lipid bilayer membranes, including the membrane thickness, the area per lipid, the lipid tail orientation, the bending rigidity, the rupture behavior, and the potential of mean force for lipid flip-flop. PMID:27137463
14. Glass Formation of n-Butanol: Coarse-grained Molecular Dynamics Simulations Using Gay-Berne Potential Model
Xie, Gui-long; Zhang, Yong-hong; Huang, Shi-ping
2012-04-01
Using coarse-grained molecular dynamics simulations based on Gay-Berne potential model, we have simulated the cooling process of liquid n-butanol. A new set of GB parameters are obtained by fitting the results of density functional theory calculations. The simulations are carried out in the range of 290-50 K with temperature decrements of 10 K. The cooling characteristics are determined on the basis of the variations of the density, the potential energy and orientational order parameter with temperature, whose slopes all show discontinuity. Both the radial distribution function curves and the second-rank orientational correlation function curves exhibit splitting in the second peak. Using the discontinuous change of these thermodynamic and structure properties, we obtain the glass transition at an estimate of temperature Tg=120±10 K, which is in good agreement with experimental results 110±1 K.
15. Bacteriocin AS-48 binding to model membranes and pore formation as revealed by coarse-grained simulations.
PubMed
Cruz, Victor L; Ramos, Javier; Melo, Manuel N; Martinez-Salazar, Javier
2013-11-01
Bacteriocin AS-48 is a membrane-interacting peptide that acts as a broad-spectrum antimicrobial against Gram-positive and Gram-negative bacteria. Prior Nuclear Magnetic Resonance experiments and the high resolution crystal structure of AS-48 have suggested a mechanism for the molecular activity of AS-48 whereby the peptide undergoes transition from a water-soluble to a membrane-bound state upon membrane binding. To help interpret experimental results, we here simulate the molecular dynamics of this binding mechanism at the coarse-grained level. By simulating the self-assembly of the peptide, we predict induction by the bacteriocin of different pore types consistent with a "leaky slit" model.
16. Coarse-grained density and compressibility of nonideal crystals: General theory and an application to cluster crystals
Häring, J. M.; Walz, C.; Szamel, G.; Fuchs, M.
2015-11-01
The isothermal compressibility of a general crystal is analyzed within classical density functional theory. Our approach can be used for homogeneous and unstrained crystals containing an arbitrarily high density of local defects. We start by coarse-graining the microscopic particle density and then obtain the long-wavelength limits of the correlation functions of elasticity theory and the thermodynamic derivatives. We explicitly show that the long-wavelength limit of the microscopic density correlation function differs from the isothermal compressibility. We apply our theory to crystals consisting of soft particles which can multiply occupy lattice sites ("cluster crystals"). The multiple occupancy results in a strong local disorder over an extended range of temperatures. We determine the cluster crystals' isothermal compressibility, the fluctuations of the lattice occupation numbers and their correlation functions, and the dispersion relations. We also discuss their low-temperature phase diagram.
17. Dissipative Particle Dynamics Simulations for Phospholipid Membranes Based on a Four-To-One Coarse-Grained Mapping Scheme
PubMed Central
Li, Xiaoxu; Gao, Lianghui; Fang, Weihai
2016-01-01
In this article, a new set of parameters compatible with the dissipative particle dynamics (DPD) force field is developed for phospholipids. The coarse-grained (CG) models of these molecules are constructed by mapping four heavy atoms and their attached hydrogen atoms to one bead. The beads are divided into types distinguished by charge type, polarizability, and hydrogen-bonding capacity. First, we derive the relationship between the DPD repulsive force and Flory-Huggins χ-parameters based on this four-to-one CG mapping scheme. Then, we optimize the DPD force parameters for phospholipids. The feasibility of this model is demonstrated by simulating the structural and thermodynamic properties of lipid bilayer membranes, including the membrane thickness, the area per lipid, the lipid tail orientation, the bending rigidity, the rupture behavior, and the potential of mean force for lipid flip-flop. PMID:27137463
18. Ultrasonic Phased Array Sound Field Mapping Through Large-Bore Coarse Grained Cast Austenitic Stainless Steel (CASS) Piping Materials
SciTech Connect
Cinson, Anthony D.; Crawford, Susan L.; Prowant, Matthew S.; Diaz, Aaron A.; Hathaway, John E.; Anderson, Michael T.
2012-04-16
A sound field beam mapping exercise was conducted to further understand the effects of coarse grained microstructures found in CASS materials on phased array ultrasonic wave propagation. Laboratory measurements were made on three CASS specimens with different microstructures; the specimens were polished and etched to reveal measurable grain sizes, shapes and orientations. Three longitudinal, phased array probes were fixed on a specimen's outside diameter with the sound field directed toward one end (face) of the pipe segment over a fixed range of angles. A point receiver was raster scanned over the surface of the specimen face generating a sound field image. A slice of CASS material was then removed from the specimen end and the beam mapping exercise repeated. The sound fields acquired were analyzed for spot size, coherency, and beam redirection. Analyses were conducted between the resulting sound fields and the microstructural characteristics of each specimen.
19. Cleavage initiation in the intercritically reheated coarse-grained heat affected zone. Part 2: Failure criteria and statistical effects
SciTech Connect
Davis, C.L.; King, J.E.
1996-10-01
In part 1 of this article, cleavage initiation in the intercritically reheated coarse-grained heat affected zone (IC CG HAZ) of high-strength low-alloy (HSLA) steels was determined to occur between two closely spaced blocky MA particles. Blunt notch, crack tip opening displacement (CTOD), and precracked Charpy testing were used in this investigation to determine the failure criteria required for cleavage initiation to occur by this mechanism in the IC CG HAZ. It was found that the attainment of a critical level of strain was required in addition to a critical level of stress. This does not occur in the case of high strain rate testing, for example, during precracked Charpy testing. A different cleavage initiation mechanism is then found to operate. The precise fracture criteria and microstructural requirements (described in part 1 of this article) result in competition between potential cleavage initiation mechanisms in the IC CG HAZ.
20. One-particle-thick, solvent-free, coarse-grained model for biological and biomimetic fluid membranes
Yuan, Hongyan; Huang, Changjin; Li, Ju; Lykotrafitis, George; Zhang, Sulin
2010-07-01
Biological membranes are involved in numerous intriguing biophysical and biological cellular phenomena of different length scales, ranging from nanoscale raft formation, vesiculation, to microscale shape transformations. With extended length and time scales as compared to atomistic simulations, solvent-free coarse-grained membrane models have been exploited in mesoscopic membrane simulations. In this study, we present a one-particle-thick fluid membrane model, where each particle represents a cluster of lipid molecules. The model features an anisotropic interparticle pair potential with the interaction strength weighed by the relative particle orientations. With the anisotropic pair potential, particles can robustly self-assemble into fluid membranes with experimentally relevant bending rigidity. Despite its simple mathematical form, the model is highly tunable. Three potential parameters separately and effectively control diffusivity, bending rigidity, and spontaneous curvature of the model membrane. As demonstrated by selected examples, our model can naturally simulate dynamics of phase separation in multicomponent membranes and the topological change of fluid vesicles.
1. More than the sum of its parts: Coarse-grained peptide-lipid interactions from a simple cross-parametrization
PubMed Central
Bereau, Tristan; Wang, Zun-Jing; Deserno, Markus
2014-01-01
Interfacial systems are at the core of fascinating phenomena in many disciplines, such as biochemistry, soft-matter physics, and food science. However, the parametrization of accurate, reliable, and consistent coarse-grained (CG) models for systems at interfaces remains a challenging endeavor. In the present work, we explore to what extent two independently developed solvent-free CG models of peptides and lipids—of different mapping schemes, parametrization methods, target functions, and validation criteria—can be combined by only tuning the cross-interactions. Our results show that the cross-parametrization can reproduce a number of structural properties of membrane peptides (for example, tilt and hydrophobic mismatch), in agreement with existing peptide-lipid CG force fields. We find encouraging results for two challenging biophysical problems: (i) membrane pore formation mediated by the cooperative action of several antimicrobial peptides, and (ii) the insertion and folding of the helix-forming peptide WALP23 in the membrane. PMID:24655203
2. More than the sum of its parts: Coarse-grained peptide-lipid interactions from a simple cross-parametrization
Bereau, Tristan; Wang, Zun-Jing; Deserno, Markus
2014-03-01
Interfacial systems are at the core of fascinating phenomena in many disciplines, such as biochemistry, soft-matter physics, and food science. However, the parametrization of accurate, reliable, and consistent coarse-grained (CG) models for systems at interfaces remains a challenging endeavor. In the present work, we explore to what extent two independently developed solvent-free CG models of peptides and lipids—of different mapping schemes, parametrization methods, target functions, and validation criteria—can be combined by only tuning the cross-interactions. Our results show that the cross-parametrization can reproduce a number of structural properties of membrane peptides (for example, tilt and hydrophobic mismatch), in agreement with existing peptide-lipid CG force fields. We find encouraging results for two challenging biophysical problems: (i) membrane pore formation mediated by the cooperative action of several antimicrobial peptides, and (ii) the insertion and folding of the helix-forming peptide WALP23 in the membrane.
3. Coarse-grained modelling of triglyceride crystallisation: a molecular insight into tripalmitin tristearin binary mixtures by molecular dynamics simulations
Pizzirusso, Antonio; Brasiello, Antonio; De Nicola, Antonio; Marangoni, Alejandro G.; Milano, Giuseppe
2015-12-01
The first simulation study of the crystallisation of a binary mixture of triglycerides using molecular dynamics simulations is reported. Coarse-grained models of tristearin (SSS) and tripalmitin (PPP) molecules have been considered. The models have been preliminarily tested in the crystallisation of pure SSS and PPP systems. Two different quenching procedures have been tested and their performances have been analysed. The structures obtained from the crystallisation procedures show a high orientation order and a high content of molecules in the tuning fork conformation, comparable with the crystalline α phase. The behaviour of melting temperatures for the α phase of the mixture SSS/PPP obtained from the simulations is in qualitative agreement with the behaviour that was experimentally determined.
4. An analytical coarse-graining method which preserves the free energy, structural correlations, and thermodynamic state of polymer melts from the atomistic to the mesoscale
SciTech Connect
McCarty, J.; Clark, A. J.; Copperman, J.; Guenza, M. G.
2014-05-28
Structural and thermodynamic consistency of coarse-graining models across multiple length scales is essential for the predictive role of multi-scale modeling and molecular dynamic simulations that use mesoscale descriptions. Our approach is a coarse-grained model based on integral equation theory, which can represent polymer chains at variable levels of chemical details. The model is analytical and depends on molecular and thermodynamic parameters of the system under study, as well as on the direct correlation function in the k → 0 limit, c{sub 0}. A numerical solution to the PRISM integral equations is used to determine c{sub 0}, by adjusting the value of the effective hard sphere diameter, d{sub HS}, to agree with the predicted equation of state. This single quantity parameterizes the coarse-grained potential, which is used to perform mesoscale simulations that are directly compared with atomistic-level simulations of the same system. We test our coarse-graining formalism by comparing structural correlations, isothermal compressibility, equation of state, Helmholtz and Gibbs free energies, and potential energy and entropy using both united atom and coarse-grained descriptions. We find quantitative agreement between the analytical formalism for the thermodynamic properties, and the results of Molecular Dynamics simulations, independent of the chosen level of representation. In the mesoscale description, the potential energy of the soft-particle interaction becomes a free energy in the coarse-grained coordinates which preserves the excess free energy from an ideal gas across all levels of description. The structural consistency between the united-atom and mesoscale descriptions means the relative entropy between descriptions has been minimized without any variational optimization parameters. The approach is general and applicable to any polymeric system in different thermodynamic conditions.
5. A percentile-based coarse graining approach is helpful in symbolizing heart rate variability during graded head-up tilt.
PubMed
Cysarz, Dirk; Edelhauser, Friedrich; Javorka, Michal; Montano, Nicola; Porta, Alberto
2015-01-01
Coarse graining of physiological time series such as the cardiac interbeat interval series by means of a symbolic transformation retains information about dynamical properties of the underlying system and complements standard measures of heart rate variability. The transformations of the original time series to the coarse grained symbolic series usually lead to a non-uniform occurrence of the different symbols, i.e. some symbols appear more often than others influencing the results of the subsequent symbolic series analysis. Here, we defined a transformation procedure to assure that each symbol appears with equal probability using a short alphabet {0,1,2,3} and a long alphabet {0,1,2,3,4,5}. The procedure was applied to the cardiac interbeat interval series RRi of 17 healthy subjects obtained during graded head-up tilt testing. The symbolic dynamics is analyzed by means of the occurrence of short sequences (`words') of length 3. The occurrence of words is grouped according to words without variations of the symbols (0V%), one variation (1V%), two like variations (2LV%) and two unlike variations (2UV%). Linear regression analysis with respect to tilt angle showed that for the short alphabet 0V% increased with increasing tilt angle whereas 1V%, 2LV% and 2UV% decreased. For the long alphabet 0V%, and 1V% increased with increasing tilt angle whereas 2LV% and 2UV% decreased. These results were slightly better compared to the results from non-uniform symbolic transformations reflecting the deviation from the mean. In conclusion, the symbolic transformation assuring the appearance of symbols with equal probability is capable of reflecting changes of the cardiac autonomic nervous system during graded head-up tilt. Furthermore, the transformation is independent of the time series' distribution. PMID:26736256
6. Coarse-graining dipolar interactions in simple fluids and polymer solutions: Monte Carlo studies of the phase behavior.
PubMed
Mognetti, B M; Virnau, P; Yelash, L; Paul, W; Binder, K; Müller, M; MacDowell, L G
2009-03-28
In this paper we investigate the phase diagram of pure dipolar substances and their mixtures with short alkanes, using grand canonical Monte Carlo simulations of simplified coarse-grained models. Recently, an efficient coarse-grained model for simple quadrupolar molecules, based on a Lennard-Jones (LJ) interaction plus a spherically averaged quadrupolar potential, has been shown to be successful in predicting single-component and mixture phase diagrams. Motivated by these results, we investigate the phase diagrams of simple dipolar molecules (and their mixtures with alkanes) using a spherically averaged potential. First, we test the model on pure components. A generalized (state-dependent) mapping procedure allows us to recycle Monte Carlo results of the simple Lennard-Jones (LJ) potential. Considering ammonia, nitrous oxide, and hydrogen sulfide, we generally observe improvements in the single-component phase diagram compared to a pure LJ description, but also some discrepancies in the coexistence pressure near the critical point and in the liquid branch of the coexistence densities well below criticality. In addition, we present results for mixtures. We consider mixtures of ammonia (NH3) with methane (CH4), nonane (C9H20) and hexadecane (C16H34)--for which experimental results are available--and compare the predictions from this modeling ansatz with predictions from simple LJ models. We also present results for the hydrogen sulfide-pentane mixture (H2S and C5H12) for which big discrepancies between simulations and experiments are present. Possible explanations for these discrepancies and limitations of the modeling are discussed.
7. Methane Hydrate Formation in a Saturated, Coarse-Grained Sample through the Induction of a Propagating Gas Front
Meyer, D.; You, K.; Borgfeldt, T.; Flemings, P. B.; DiCarlo, D. A.; Kneafsey, T. J.
2015-12-01
We generate methane hydrate in the laboratory in a coarse-grained, brine-saturated, vertically-oriented sample through gas injection. The sample (5.125 inch length; 2 inch diameter; 0.383 porosity) was initially pressurized to 12.24 MPa (1775 psi), cooled to 1 degree Celsius, and saturated with a 7 wt% NaBr solution. A syringe pump was filled with methane gas and connected to the top of the sample at a constant pressure. Another pump was used to withdraw brine from the base of the sample at a constant rate (0.003 mL/min), pulling methane into the sample and initiating hydrate formation. Based on mass balance calculations, derived from the mass of water withdrawn and the mass of methane consumed, the bulk saturations of water, hydrate, and gas reached final values of 0.683, 0.278, and 0.038, respectively. The computed-tomography (CT) scans confirm a downward-propagating low density front, which we interpret as the front of the region where hydrate is forming and free gas is replacing withdrawn water. Assuming that hydrate formation and gas presence is limited to the region behind this front increases the hydrate and gas saturations to 0.452 and 0.062, respectively. Additional analysis of the CT scans indicates a heterogeneous distribution of gas, hydrate, and water within the core and provides insight into hydrate formation behavior and the thermodynamic state of hydrate in gas-rich, coarse-grained systems.
8. Coarse-grained and fine-grained parallel optimization for real-time en-face OCT imaging
2016-03-01
This paper presents parallel optimizations in the en-face (C-scan) optical coherence tomography (OCT) display. Compared with the cross-sectional (B-scan) imagery, the production of en-face images is more computationally demanding, due to the increased size of the data handled by the digital signal processing (DSP) algorithms. A sequential implementation of the DSP leads to a limited number of real-time generated en-face images. There are OCT applications, where simultaneous production of large number of en-face images from multiple depths is required, such as real-time diagnostics and monitoring of surgery and ablation. In sequential computing, this requirement leads to a significant increase of the time to process the data and to generate the images. As a result, the processing time exceeds the acquisition time and the image generation is not in real-time. In these cases, not producing en-face images in real-time makes the OCT system ineffective. Parallel optimization of the DSP algorithms provides a solution to this problem. Coarse-grained central processing unit (CPU) based and fine-grained graphics processing unit (GPU) based parallel implementations of the conventional Fourier domain (CFD) OCT method and the Master-Slave Interferometry (MSI) OCT method are studied. In the coarse-grained CPU implementation, each parallel thread processes the whole OCT frame and generates a single en-face image. The corresponding fine-grained GPU implementation launches one parallel thread for every data point from the OCT frame and thus achieves maximum parallelism. The performance and scalability of the CPU-based and GPU-based parallel approaches are analyzed and compared. The quality and the resolution of the images generated by the CFD method and the MSI method are also discussed and compared.
9. C -IBI: Targeting cumulative coordination within an iterative protocol to derive coarse-grained models of (multi-component) complex fluids
de Oliveira, Tiago E.; Netz, Paulo A.; Kremer, Kurt; Junghans, Christoph; Mukherji, Debashish
2016-05-01
We present a coarse-graining strategy that we test for aqueous mixtures. The method uses pair-wise cumulative coordination as a target function within an iterative Boltzmann inversion (IBI) like protocol. We name this method coordination iterative Boltzmann inversion ( C -IBI). While the underlying coarse-grained model is still structure based and, thus, preserves pair-wise solution structure, our method also reproduces solvation thermodynamics of binary and/or ternary mixtures. Additionally, we observe much faster convergence within C -IBI compared to IBI. To validate the robustness, we apply C -IBI to study test cases of solvation thermodynamics of aqueous urea and a triglycine solvation in aqueous urea.
10. The Effect of Cold Plastic Straining of Submicrocrystalline and Coarse-Grained Titanium on the Temperature Behavior of Flow Stress in the Stage of Microplastic Deformation
Dudarev, E. F.; Pochivalova, G. P.; Kolobov, Yu. R.; Bakach, G. P.; Skosyrskii, A. B.; Zhorovkov, M. F.; Goraynov, А. А.
2013-10-01
The results of an experimental investigation of the effect of mechanical-thermal treatment of submicrocrystalline and coarse-grained titanium on the deformation behavior in the stage of microplastic deformation at room and elevated temperatures are reported. The structural factors giving rise to the flowstress changes in the stage of microplastic deformation as a result of mechanical-thermal treatment are discussed. The general tendencies and special features of the effect of annealing and testing temperatures on the deformation behavior and flow stress in the first and second stages of microplastic deformation of submicrocrystalline and coarse-grained titanium subjected to large plastic deformation at 295 K are clarified.
11. Conformational state distributions and catalytically relevant dynamics of a hinge-bending enzyme studied by single-molecule FRET and a coarse-grained simulation.
PubMed
Gabba, Matteo; Poblete, Simón; Rosenkranz, Tobias; Katranidis, Alexandros; Kempe, Daryan; Züchner, Tina; Winkler, Roland G; Gompper, Gerhard; Fitter, Jörg
2014-10-21
Over the last few decades, a view has emerged showing that multidomain enzymes are biological machines evolved to harness stochastic kicks of solvent particles into highly directional functional motions. These intrinsic motions are structurally encoded, and Nature makes use of them to catalyze chemical reactions by means of ligand-induced conformational changes and states redistribution. Such mechanisms align reactive groups for efficient chemistry and stabilize conformers most proficient for catalysis. By combining single-molecule Förster resonance energy transfer measurements with normal mode analysis and coarse-grained mesoscopic simulations, we obtained results for a hinge-bending enzyme, namely phosphoglycerate kinase (PGK), which support and extend these ideas. From single-molecule Förster resonance energy transfer, we obtained insight into the distribution of conformational states and the dynamical properties of the domains. The simulations allowed for the characterization of interdomain motions of a compact state of PGK. The data show that PGK is intrinsically a highly dynamic system sampling a wealth of conformations on timescales ranging from nanoseconds to milliseconds and above. Functional motions encoded in the fold are performed by the PGK domains already in its ligand-free form, and substrate binding is not required to enable them. Compared to other multidomain proteins, these motions are rather fast and presumably not rate-limiting in the enzymatic reaction. Ligand binding slightly readjusts the orientation of the domains and feasibly locks the protein motions along a preferential direction. In addition, the functionally relevant compact state is stabilized by the substrates, and acts as a prestate to reach active conformations by means of Brownian motions. PMID:25418172
12. Potential of mean force analysis of the self-association of leucine-rich transmembrane α-helices: Difference between atomistic and coarse-grained simulations
Nishizawa, Manami; Nishizawa, Kazuhisa
2014-08-01
Interaction of transmembrane (TM) proteins is important in many biological processes. Large-scale computational studies using coarse-gr | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7202595472335815, "perplexity": 2498.5841478564516}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-13/segments/1490218203536.73/warc/CC-MAIN-20170322213003-00413-ip-10-233-31-227.ec2.internal.warc.gz"} |
http://tex.stackexchange.com/questions/38427/custom-alignment-of-columns-in-align-environment | # Custom alignment of columns in align environment
I need to typeset two columns of equations, each row typeset with an equation number to the right as with an ordinary equation. The first column must be centered, and the second column must be left-aligned. There will be many rows, so it must automatically break at a page break as appropriate.
There are plenty of related questions, but I can't find any existing solutions that will let me do exactly what I want. (It's a real pain the align environment can't take optional column alignment specifiers.)
-
How are the equations going to be numbered? For instance, will all equations in the left-hand column be numbered independently from those in the right-hand column, or will they share the same counter? – Mico Dec 15 '11 at 21:04
The idea is that each line would have one number, typeset to the right, like an ordinary align environment. The only difference to align is that instead of rl column alignment, I need cl column alignment. – Jamie Vicary Dec 15 '11 at 21:15
Would it be acceptable if the first column were left-aligned or aligned at an operator? – rdhs Dec 15 '11 at 22:06
Hi, thanks for your comment. Unfortunately the first column does need to be centre-aligned. And entries in the first column are actually going to be graphical diagrams, so there are no characters to align at. – Jamie Vicary Dec 15 '11 at 22:14
Making align break across pages is simple: add \allowdisplaybreaks[1] to your preamble.
And since your first column is text, it's also trivial to center it within align: just wrap it in a \makebox larger than all the images (which centers its contents) and use align as normal.
\documentclass{article}
\usepackage{amsmath}
\allowdisplaybreaks[1]
\newcommand{\centerdia}[1]{\makebox[2in]{\includegraphics{#1}}}
\begin{document}
\begin{align}
\centerdia{dia1} & c=20x^2+5x-10+\frac{x^3-4x^2+500x-f(240)}{50} \\
\centerdia{dia2} & \mu=10*\epsilon\\
\centerdia{dia3} & \mu=10*\epsilon
\end{align}
\end{document}
-
Use a modified version of align; change 2\tabcolsep into the separation you prefer.
\documentclass{article}
\usepackage{amsmath,environ}
\makeatletter
\NewEnviron{specialalign}
{\def\align@preamble{%
&\hfil
\strut@
\setboxz@h{\@lign$\m@th\displaystyle{####}$}%
\ifmeasuring@\savefieldlength@\fi
\set@field
\hfil
\tabskip2\tabcolsep
&\setboxz@h{\@lign$\m@th\displaystyle{{}####}$}%
\ifmeasuring@\savefieldlength@\fi
\set@field
\hfil
\tabskip\alignsep@
}%
\begin{align}\BODY\end{align}}
\makeatother
\begin{document}
\begin{specialalign}
x & a=b \\
yyy & c=d+e+f \\
zzzzzz & 1\ne0
\end{specialalign}
\end{document}
-
Just add \allowdisplaybreaks[1] if needed to break across pages. Nice solution! – Werner Dec 15 '11 at 23:24
It's better to avoid \allowdisplaybreaks and add \displaybreak where really needed (before the \\ after which the break should take place). \allowdisplaybreaks is useful during document preparation. – egreg Dec 15 '11 at 23:27 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 2, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9602036476135254, "perplexity": 2435.835083769133}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-11/segments/1424936462982.10/warc/CC-MAIN-20150226074102-00154-ip-10-28-5-156.ec2.internal.warc.gz"} |
https://www.physicsforums.com/threads/calculate-heat-of-vaporization-and-normal-boing-point-in-degree-c.673231/ | # Calculate Heat of Vaporization and normal boing point (in degree C).?
1. Feb 20, 2013
### laughingnahga
Using line equation y = -4058.7x + 16.10 with the experiment pressure measured in kPa instead of atm.
I already solved for heat of vaporization thus:
(-4058.7K)(-8.314 J/mol $\ast$K)=heat of vaporization = 33444 J/mol = 33.44 kJ/mol.
Also, the vapor pressure for normal boiling point:
(1atm)(101325 Pa/1atm)(1 kPa/1000 Pa)=101.32 kPa
I attempted to solve for T by rearranging the linear form of the Clausius-Clapeyron equation, ln Pvap = (-$\Delta$H/R)(1/T) + ln $\beta$ into something like this (ln101.32 kPa)(-33444 J/mol $\div$ 8.413 J/mol * K)$\div$1 - ln16.10 = T but I got something insane like 21857.7 K which even with subtracting 273 to get C is no where near close to the answer choices provided.
Any help with the last part would be greatly appreciated.
2. Feb 20, 2013
### Staff: Mentor
Re: Calculate Heat of Vaporization and normal boing point (in degree C
Telling us what is x and what is y should slightly increase chances that someone will try to understand the problem and what you did.
3. Feb 20, 2013
### laughingnahga
Re: Calculate Heat of Vaporization and normal boing point (in degree C
I had to turn the assignment in this afternoon so it really doesn't matter at this point.
Thanks anyway...
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http://mymathforum.com/abstract-algebra/46415-invertible-martices.html | My Math Forum Invertible Martices
Abstract Algebra Abstract Algebra Math Forum
September 16th, 2014, 08:58 PM #1 Newbie Joined: Sep 2014 From: Canada Posts: 2 Thanks: 0 Invertible Martices Let $\displaystyle S$ be a set of $\displaystyle d \times d$ matrices of a field of order $\displaystyle q$, such that the difference of any two distinct matrices in $\displaystyle S$ is invertible. Prove that $\displaystyle |S| \leq q^d.$ I know that the set of $\displaystyle d \times d$ matrices is equal to $\displaystyle q^d$ so this question seems trivial and I don't know where to start.
September 16th, 2014, 11:12 PM #2 Newbie Joined: Sep 2014 From: Canada Posts: 2 Thanks: 0 The set of dxd matrices would have cardinality $\displaystyle q^{d^2}$ but I don't know where to go from there.
Tags field, fields, invertible, martices
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Contact - Home - Forums - Cryptocurrency Forum - Top | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.605618417263031, "perplexity": 1960.53976079651}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-26/segments/1560628000175.78/warc/CC-MAIN-20190626053719-20190626075719-00063.warc.gz"} |
http://mathhelpforum.com/calculus/201838-natural-log-equations-question.html | # Math Help - Natural log equations question
1. ## Natural log equations question
The equation 3lnx=lb3x is solved by the sqaure root of 3.
Thanks
2. ## Re: Natural log equations question
3ln(x) = ln(3x)
ln(x3) = ln(3x)
x3 = 3x
x3 - 3x = 0
x (x2 - 3) = 0
x = 0 or else x2 - 3 = 0
Edited...
4. ## Re: Natural log equations question
Originally Posted by tom@ballooncalculus
3ln(x) = ln(3x)
ln(x3) = ln(3x)
x3 = 3x
x3 - 3x = 0
x (x2 - 3) = 0
x = 0 or else x2 - 3 = 0
Note that \displaystyle \begin{align*} x = 0 \end{align*} and \displaystyle \begin{align*} x = -\sqrt{3} \end{align*} are NOT acceptable solutions, because \displaystyle \begin{align*} \ln{x} \end{align*} is only defined for \displaystyle \begin{align*} x > 0 \end{align*}. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 4, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.967976987361908, "perplexity": 3538.865264576}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-22/segments/1464049276964.14/warc/CC-MAIN-20160524002116-00074-ip-10-185-217-139.ec2.internal.warc.gz"} |
https://readpaper.com/paper/4705295339523948545 | This website requires JavaScript.
# The $X(3872)\rightarrow J/\psi \pi \gamma$ and $X(3872)\rightarrow J/\psi \pi\pi \gamma$ decays
Dec 2022
We study the $\rho$ and $\omega$ meson contribution to the radiative decays$X(3872)\rightarrow J/\psi \pi \gamma$ and $X(3872)\rightarrow J/\psi \pi\pi\gamma$. The $X(3872)\rightarrow J/\psi \pi \gamma$ is dominated by the$\omega$ meson. As for the $X(3872)\rightarrow J/\psi \pi\pi \gamma$, thecontributions of the cascade decays through the $\rho$ and $\omega$ mesons arestrongly suppressed with respect to the diagrams which proceed either throughthe $\psi(2S)$ or the three body decay of $\rho$. The branching ratios of$X(3872)\rightarrow J/\psi \pi \gamma$ and $X(3872)\rightarrow J/\psi \pi\pi\gamma$ are $(8.10^{+3.50}_{-2.88})\times10^{-3}$ and $(2.38\pm1.06)\%$, whichmay be accessible by the BESIII and LHCb Collaborations. Especailly, the$X(3872)\rightarrow J/\psi \pi \gamma$ and $X(3872)\rightarrow J/\psi\pi^+\pi^- \gamma$ decays can be employed to extract the couplings$g_{X\psi\omega}$ and $g_{X\psi\rho}$, which probe the isoscalar and isovectorcomponents of the X(3872) wave function respectively.
Q1论文试图解决什么问题？
Q2这是否是一个新的问题？
Q3这篇文章要验证一个什么科学假设？
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https://www.aimsciences.org/article/doi/10.3934/proc.2009.2009.800 | American Institute of Mathematical Sciences
2009, 2009(Special): 800-809. doi: 10.3934/proc.2009.2009.800
Random attractors for wave equations on unbounded domains
1 Department of Mathematics, New Mexico Institute of Mining and Technology, Socorro, NM 87801, United States, United States
Received July 2008 Revised April 2009 Published September 2009
The asymptotic behavior of stochastic wave equations on $\mathbb{R}^n$ is studied. The existence of a random attractor for the corresponding random dynamical system in $H^1(\mathbb{R}^n) \times L^2(\mathbb{R}^n)$ is established, where the nonlinearity has an arbitrary growth order for $n \le 2$ and is subcritical for $n=3$.
Citation: Bixiang Wang, Xiaoling Gao. Random attractors for wave equations on unbounded domains. Conference Publications, 2009, 2009 (Special) : 800-809. doi: 10.3934/proc.2009.2009.800
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https://kb.osu.edu/dspace/handle/1811/31410 | # EXPERIMENTAL AND THEORETICAL STUDY OF WATER-VAPOR CONTINUUM ABSORPTION IN THE THZ REGION FROM 0.3 TO 2.7 THZ
Please use this identifier to cite or link to this item: http://hdl.handle.net/1811/31410
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Title: EXPERIMENTAL AND THEORETICAL STUDY OF WATER-VAPOR CONTINUUM ABSORPTION IN THE THZ REGION FROM 0.3 TO 2.7 THZ Creators: Podobedov, V. B.; Plusquellic, D. F.; Siegrist, K.; Fraser, G. T.; Ma, Q.; Tipping, R. H. Issue Date: 2007 Abstract: Experimental results and theoretical calculations of the continuum absorption by water vapor in the far-IR region from 10 to 90 cm$^{-1}$ (0.3 to 2.7 THz) are presented for the temperature range from 293 to 333 K. The contributions to absorbance resulting from both structureless H$_2$O-H$_2$O and H$_2$O-N$_2$ continua have been measured over a wide pressure range with a spectral resolution of 0.04 to 0.12 cm$^{-1}$. The presentation will include the analysis of the experimental broadband THz technique (Fourier transform spectroscopy) and enhanced absorption in a temperature-controlled multipass cell}. The resonant water vapor spectrum was modeled using the HITRAN04 data base and VVW lineshape. After subtracting local contributions from the raw absorbance data, the H$_2$O-H$_2$O (self) and H$_2$O-N$_2$ (foreign) continua were derived both by fitting the entire frequency region based on an assumed quadratic frequency dependence and by fitting to each of the THz windows individually. From experiment, the absorption coefficients of 3.83 and 0.185 (dB/km)/(kPa THz)$^2$ and temperature exponents of 8.8 and 5.7 were found for the self- and foreign-gas continuum, respectively. Experimental absorption coefficients and temperature exponents of the foreign-continuum obtained from individual THz widows were compared to theoretical calculations based on the modified Lanczos method}. URI: http://hdl.handle.net/1811/31410 Other Identifiers: 2007-MG-11 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7872421145439148, "perplexity": 16638.88261760466}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-10/segments/1394010444750/warc/CC-MAIN-20140305090724-00032-ip-10-183-142-35.ec2.internal.warc.gz"} |
https://www.fishtanklearning.org/curriculum/math/5th-grade/shapes-and-volume/ | # Shapes and Volume
Students explore the volume of three-dimensional shapes, connecting it to the operations of multiplication and addition, as well as classify two-dimensional shapes hierarchically.
Math
Unit 3
## Unit Summary
In Unit 3, students will explore volume of three-dimensional shapes (5.MD.3—5), connecting it to the operations of multiplication and addition (5.NBT.5, 4.NBT.4). They also use their understanding that they gradually built in prior grade levels to classify shapes in a hierarchy, seeing that attributes of shapes in one category belong to shapes in all subcategories of that category (5.G.3—4).
In prior grade levels, students explored the idea of volume informally, comparing the capacity of various containers as being able to “hold more” or “hold less” (K.MD.2). Students have also explored one-dimensional and two-dimensional measurements of figures, developing a deep understanding of length in Grade 2 and of area in Grade 3. In their exploration of area in Grade 3, students come to understand area as an attribute of plane figures (3.MD.5) and measure it by counting unit squares (3.MD.6), and they connect area to the operations of multiplication and addition (3.MD.7).
Students have also explored two-dimensional shapes and their attributes extensively in previous grades. “From Kindergarten on, students experience all of the properties of shapes that they will study in Grades K–7, recognizing and working with these properties in increasingly sophisticated ways” (Geometry Progression, p. 3). In Kindergarten through Grade 2, students focused on building understanding of shapes and their properties. In Grade 3, students started to conceptualize shape categories, in particular quadrilaterals. In Grade 4, work with angle measure (4.MD.5—7) lent itself to classifying figures based on the presence or absence of parallel and perpendicular sides.
Thus, this unit builds off of students’ well-established understanding of geometry and geometric measurement. Similar to students’ work with area, students develop an understanding of volume as an attribute of solid figures (5.MD.3) and measure it by counting unit cubes (5.MD.4). Students then connect volume to the operation of multiplication of length, width, and height or of the area of the base and the height; they also connect it to the operation of addition to find composite area (5.MD.5). Throughout Topic A, students have an opportunity to use appropriate tools strategically (MP.5) and make use of structure of three-dimensional figures (MP.7) to draw conclusions about how to find the volume of a figure.
Students then move on to classifying flat shapes into categories and see that attributes belonging to shapes in one category are shared by all subcategories of that category (5.G.3). This allows students to create a hierarchy of shapes over the course of many days (5.G.4). Throughout this topic, students use appropriate tools strategically (MP.5) to verify various attributes of shapes including their angle measure and presence of parallel or perpendicular lines, as well as attend to precision in their use of language when referring to geometric figures (MP.6). They also look for and make use of structure to construct a hierarchy based on properties (MP.7).
In Grade 6, students will explore concepts of length, area, and volume with more complex figures, such as finding the area of right triangles or finding the volume of right rectangular prisms with non-whole-number measurements (6.G.1, 6.G.2). Students will even rely on their understanding of shapes and their attributes to prove various geometric theorems in high school (GEO.G-CO.9—11). Thus, this unit provides a nice foundation for connections in many grades to come.
Pacing: 17 instructional days (15 lessons, 1 flex day, 1 assessment day)
Fishtank Plus for Math
Unlock features to optimize your prep time, plan engaging lessons, and monitor student progress.
## Assessment
The following assessments accompany Unit 3.
### Pre-Unit
Have students complete the Pre-Unit Assessment and Pre-Unit Student Self-Assessment before starting the unit. Use the Pre-Unit Assessment Analysis Guide to identify gaps in foundational understanding and map out a plan for learning acceleration throughout the unit.
### Mid-Unit
Have students complete the Mid-Unit Assessment after lesson 9.
### Post-Unit
Use the resources below to assess student mastery of the unit content and action plan for future units.
Expanded Assessment Package
Use student data to drive your planning with an expanded suite of unit assessments to help gauge students’ facility with foundational skills and concepts, as well as their progress with unit content.
## Unit Prep
### Intellectual Prep
Unit Launch
Prepare to teach this unit by immersing yourself in the standards, big ideas, and connections to prior and future content. Unit Launches include a series of short videos, targeted readings, and opportunities for action planning.
#### Intellectual Prep for All Units
• Read and annotate “Unit Summary” and “Essential Understandings” portion of the unit plan.
• Do all the Target Tasks and annotate them with the “Unit Summary” and “Essential Understandings” in mind.
• Take the Post-Unit Assessment.
### Essential Understandings
• Volume refers to the amount of space a three-dimensional figure takes up. Two-dimensional figures have no volume.
• You can find the volume of a rectangular prism by counting individual cubic units; counting the number of cubic units in a “layer” and multiplying by the number of layers; or multiplying the length, width, and height of the figure. The latter two strategies correspond to the formulas $${v = b \times h}$$ and $${v = l \times w \times h}$$
• You can calculate the volume of a rectangular prism by multiplying edge lengths in any order because of the associative property.
• One can “find volumes of solid figures composed of two non-overlapping right rectangular prisms by adding the volumes of the non-overlapping parts” (CCSS, standard 5.MD.5c). This is possible because volume is additive.
• Two-dimensional figures are classified by their properties into categories but can fit into more than one category at the same time. For example, a four-sided closed flat shape with one pair of parallel sides can be simultaneously classified as a polygon, a quadrilateral, and a trapezoid.
### Materials
• Centimeter cubes (Maximum of about 70 per student or small group)
• Cardstock (Total of 5 sheets per student or small group) — Printing the Nets A-E templates on cardstock will make them sturdier, but plain paper can be used if materials are limited
• Tape (1 per teacher)
• Nets A-C (1 per student or small group)
• Net D (1 per student or small group)
• Net E (1 per student or small group)
• Build My Prism Template (1 per pair of students)
• Rectangular Prisms Template (1 per pair of students)
• Markers or crayons (2 per student)
• Right-angle tool (1 per student) — This can be any tool used to verify right angle measures, e.g., a protractor, the corner of a piece of paper, etc.
• Ruler (1 per student) — This can be any tool used to draw straight lines and verify equal lengths, e.g., the edge of a piece of paper, etc.
• Polygons Template (1 per student or small group)
• Parallelograms Template (1 per student or small group)
• Triangles Template (1 per student or small group)
### Vocabulary
base
cubic units
height
hierarchy
regular polygon
rectangular prism
unit cube
volume
To see all the vocabulary for Unit 3, view our 5th Grade Vocabulary Glossary.
## Unit Practice
Word Problems and Fluency Activities
Access daily word problem practice and our content-aligned fluency activities created to help students strengthen their application and fluency skills.
## Lesson Map
Topic A: Volume of Three-Dimensional Figures
Topic B: Classification of Two-Dimensional Shapes
## Common Core Standards
Key
Major Cluster
Supporting Cluster
### Core Standards
#### Geometry
• 5.G.B.3 — Understand that attributes belonging to a category of two-dimensional figures also belong to all subcategories of that category. For example, all rectangles have four right angles and squares are rectangles, so all squares have four right angles.
• 5.G.B.4 — Classify two-dimensional figures in a hierarchy based on properties.
#### Measurement and Data
• 5.MD.C.3 — Recognize volume as an attribute of solid figures and understand concepts of volume measurement.
• 5.MD.C.3.A — A cube with side length 1 unit, called a "unit cube," is said to have "one cubic unit" of volume, and can be used to measure volume.
• 5.MD.C.3.B — A solid figure which can be packed without gaps or overlaps using n unit cubes is said to have a volume of n cubic units.
• 5.MD.C.4 — Measure volumes by counting unit cubes, using cubic cm, cubic in, cubic ft, and improvised units.
• 5.MD.C.5 — Relate volume to the operations of multiplication and addition and solve real world and mathematical problems involving volume.
• 5.MD.C.5.A — Find the volume of a right rectangular prism with whole-number side lengths by packing it with unit cubes, and show that the volume is the same as would be found by multiplying the edge lengths, equivalently by multiplying the height by the area of the base. Represent threefold whole-number products as volumes, e.g., to represent the associative property of multiplication.
• 5.MD.C.5.B — Apply the formulas V = l × w × h and V = b × h for rectangular prisms to find volumes of right rectangular prisms with whole-number edge lengths in the context of solving real world and mathematical problems.
• 5.MD.C.5.C — Recognize volume as additive. Find volumes of solid figures composed of two non-overlapping right rectangular prisms by adding the volumes of the non-overlapping parts, applying this technique to solve real world problems.
• 3.G.A.1
• 4.G.A.2
• 3.MD.C.5
• 3.MD.C.6
• 3.MD.C.7
• 4.MD.A.3
• 5.NBT.B.5
• 5.NBT.B.6
• 3.OA.B.5
• 6.G.A.1
• 6.G.A.2
### Standards for Mathematical Practice
• CCSS.MATH.PRACTICE.MP1 — Make sense of problems and persevere in solving them.
• CCSS.MATH.PRACTICE.MP2 — Reason abstractly and quantitatively.
• CCSS.MATH.PRACTICE.MP3 — Construct viable arguments and critique the reasoning of others.
• CCSS.MATH.PRACTICE.MP4 — Model with mathematics.
• CCSS.MATH.PRACTICE.MP5 — Use appropriate tools strategically.
• CCSS.MATH.PRACTICE.MP6 — Attend to precision.
• CCSS.MATH.PRACTICE.MP7 — Look for and make use of structure.
• CCSS.MATH.PRACTICE.MP8 — Look for and express regularity in repeated reasoning.
Unit 2
Multiplication and Division of Whole Numbers
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https://www.physicsforums.com/threads/sets-problem.156406/ | SETS problem
1. Feb 15, 2007
majeedh
this is another problem which i dont know how to start..im not sure which proof i should use to solve this problem
the problem is:
If A,B,C,and D are sets, does it follow
(A Φ B) Φ (C Φ D) = (A Φ C) Φ (B Φ D)
the symbol that is separting the characters is called the oplus symbol, thats the closet symbol i could find
the oplus symbol is a circle with one line going across it and one line going down
Last edited: Feb 15, 2007
2. Feb 15, 2007
HallsofIvy
Staff Emeritus
Darned if I know because I can't tell what symbol you used! Either write it out in letters or use LaTex.
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http://blog.jpolak.org/?tag=computation | # Calculation of an Orbital Integral
Posted by Jason Polak on 25. August 2015 · Write a comment · Categories: algebraic-geometry, number-theory · Tags: ,
In the Arthur-Selberg trace formula and other formulas, one encounters so-called ‘orbital integrals’. These integrals might appear forbidding and abstract at first, but actually they are quite concrete objects. In this post we’ll look at an example that should make orbital integrals seem more friendly and approachable. Let $k = \mathbb{F}_q$ be a finite field and let $F = k( (t))$ be the Laurent series field over $k$. We will denote the ring of integers of $F$ by $\mathfrak{o} := k[ [t]]$ and the valuation $v:F^\times\to \mathbb{Z}$ is normalised so that $v(t) = 1$.
Let $G$ be a reductive algebraic group over $\mathfrak{o}$. Orbital integrals are defined with respect to some $\gamma\in G(F)$. Often, $\gamma$ is semisimple, and regular in the sense that the orbit $G\cdot\gamma$ has maximal dimension. One then defines for a compactly supported smooth function $f:G(F)\to \mathbb{C}$ the orbital integral
$$\Ocl_\gamma(f) = \int_{I_\gamma(F)\backslash G(F)} f(g^{-1}\gamma g) \frac{dg}{dg_\gamma}.$$
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# Graphing the Mandelbrot Set
Posted by Jason Polak on 13. June 2013 · Write a comment · Categories: analysis, elementary · Tags: , ,
A class of fractals known as Mandelbrot sets, named after Benoit Mandelbrot, have pervaded popular culture and are now controlling us. Well, perhaps not quite, but have you ever wondered how they are drawn? Here is an approximation of one:
From now on, Mandelbrot set will refer to the following set: for any complex number $c$, consider the function $f:\mathbb{C}\to\mathbb{C}$ defined by $f_c(z) = z^2 + c$. We define the Mandelbrot set to be the set of complex numbers $c\in\mathbb{C}$ such that the sequence of numbers $f_c(0), f_c(f_c(0)),f_c(f_c(f_c(0))),\dots$ is bounded.
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Le MatematicheNumber of Followers: 0 Open Access journal ISSN (Print) 0373-3505 - ISSN (Online) 2037-5298 Published by Università di Catania [2 journals]
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News (blog, publications) | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7386767864227295, "perplexity": 8691.840106662368}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-51/segments/1575540533401.22/warc/CC-MAIN-20191211212657-20191212000657-00213.warc.gz"} |
https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-7/dd940094(v=ws.10) | # Building a USB Drive to Store USMT 4.0 Files and Simple Commands
To follow the steps in this procedure, you must have already installed Windows 7 by using a DVD or similar media on an existing Windows XP computer. First, you compile the components needed to create an external USB drive with the components used to carry out the migration process. You use this USB drive to migrate files from Windows.old to the appropriate full operating system locations, and you can use the USB for both Windows 7 and Windows Vista. User files are not copied to the USB drive, so you can use USB drive with at least 50 MB of free space.
#### To build a USB drive for storage
2. Burn the Windows AIK ISO file to a DVD and follow the installation instructions.
3. Once you have installed Windows AIK, copy C:\Program Files\Windows AIK\Tools\USMT\ to an external USB drive. Your USB drive must have the USMT folder in the root directory with amd64 and x86 subfolders.
4. Create a batch file for use with x86 file migrations. Open Notepad and copy the following text into a new file:
``````@ECHO OFF
If exist D:\USMT\*.* xcopy D:\USMT\*.* /e /v /y C:\Windows\USMT\
If exist E:\USMT\*.* xcopy E:\USMT\*.* /e /v /y C:\Windows\USMT\
If exist F:\USMT\*.* xcopy F:\USMT\*.* /e /v /y C:\Windows\USMT\
If exist G:\USMT\*.* xcopy G:\USMT\*.* /e /v /y C:\Windows\USMT\
If exist H:\USMT\*.* xcopy H:\USMT\*.* /e /v /y C:\Windows\USMT\
If exist I:\USMT\*.* xcopy I:\USMT\*.* /e /v /y C:\Windows\USMT\
If exist J:\USMT\*.* xcopy J:\USMT\*.* /e /v /y C:\Windows\USMT\
If exist K:\USMT\*.* xcopy K:\USMT\*.* /e /v /y C:\Windows\USMT\
Cd c:\windows\usmt\x86
The first section of the batch file determines where USMT files are kept and copies those files to the C:\Windows directory. The second section changes the directory to the newly created USMT directory. The scanstate.exe command creates a hard-link migration store at C:\store from the windows.old directory, and the loadstate.exe command remaps the hard-link files to their appropriate locations within Windows 7 or Windows Vista. You must run the batch file and the USMT folder as an administrator on the computer when performing the migration. For AMD64 bit migrations, you can modify the batch file by changing `Cd c:\windows\usmt\x86` to `Cd c:\windows\usmt\amd64`. USMT supports moving from 32-bit Windows XP to 64-bit versions of Windows 7 or Windows Vista. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8782637715339661, "perplexity": 20404.243702966396}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-22/segments/1526794870470.67/warc/CC-MAIN-20180527205925-20180527225925-00595.warc.gz"} |
https://proofwiki.org/wiki/Focus_of_Ellipse_from_Major_and_Minor_Axis | # Focus of Ellipse from Major and Minor Axis
## Theorem
Let $K$ be an ellipse whose major axis is $2 a$ and whose minor axis is $2 b$.
Let $c$ be the distance of the foci of $K$ from the center.
Then:
$a^2 = b^2 + c^2$
## Proof
Let the foci of $K$ be $F_1$ and $F_2$.
Let the vertices of $K$ be $V_1$ and $V_2$.
Let the covertices of $K$ be $C_1$ and $C_2$.
Let $P = \tuple {x, y}$ be an arbitrary point on the locus of $K$.
From the equidistance property of $K$ we have that:
$F_1 P + F_2 P = d$
where $d$ is a constant for this particular ellipse.
This is true for all points on $K$.
In particular, it holds true for $V_2$, for example.
Thus:
$\ds d$ $=$ $\ds F_1 V_2 + F_2 V_2$ $\ds$ $=$ $\ds \paren {a + c} + \paren {a - c}$ $\ds$ $=$ $\ds 2 a$
It also holds true for $C_2$:
$F_1 C_2 + F_2 C_2 = d$
Then:
$\ds F_1 C_2^2$ $=$ $\ds O F_1^2 + O C_2^2$ Pythagoras's Theorem $\ds$ $=$ $\ds c^2 + b^2$
and:
$\ds F_1 C_2^2$ $=$ $\ds O F_1^2 + O C_2^2$ Pythagoras's Theorem $\ds$ $=$ $\ds c^2 + b^2$
Thus:
$\ds F_1 C_2 + F_2 C_2$ $=$ $\ds 2 \sqrt {b^2 + c^2}$ $\ds$ $=$ $\ds 2 a$ as $2 a = d$ $\ds \leadsto \ \$ $\ds a$ $=$ $\ds \sqrt {b^2 + c^2}$ $\ds \leadsto \ \$ $\ds b^2 + c^2$ $=$ $\ds a^2$
$\blacksquare$
## Also presented as
This result is also seen presented as:
$c^2 = a^2 - b^2$ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 2, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9318457245826721, "perplexity": 147.68849897958145}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-05/segments/1642320304572.73/warc/CC-MAIN-20220124155118-20220124185118-00326.warc.gz"} |
https://enacademic.com/dic.nsf/enwiki/56741/Rifling | Rifling
Rifling refers to the helix-shaped pattern in the barrel of a firearm, which imparts a spin to a projectile around its long axis. This spin serves to gyroscopically stabilize the projectile, improving its aerodynamic stability and accuracy.
Rifling is described by its twist rate, which indicates the distance the bullet must travel to complete one full revolution, such as "1 turn in 10 inches" (1:10 inches), or "1 turn in 30 cm" (1:30 cm). A shorter distance indicates a "faster" twist, meaning that for a given velocity the projectile will be rotating at a higher spin rate.
A combination of the weight, length and shape of a projectile determines the twist rate needed to stabilize it - barrels intended for short, large-diameter projectiles like spherical lead balls require a very low twist rate, such as 1 turn in 48 inches (122 cm). [cite web |url=http://www.chuckhawks.com/54_caliber_muzzleloader.htm |title=The .54 Caliber Muzzleloader |author=Randy D. Smith |puiblisher=Chuck Hawks] Barrels intended for long, small-diameter bullets, such as the ultra-low-drag, 80-grain 0.224 inch bullets (5.2 g, 5.56 mm), use twist rates of 1 turn in 8 inches (20 cm) or faster. [cite web |url=http://www.shilen.com/calibersAndTwists.html |title=Products::Rifle Barrels::Calibers and Twists |publisher=Shilen Rifles, Inc.]
In some cases, rifling will have twist rates that increases down the length of the barrel, called a "gain twist"; a twist rate that decreases from breech to muzzle is undesirable, as it cannot reliably stabilize the bullet as it travels down the bore. [cite web |url=http://www.midwayusa.com/guntecdictionary.exe/showterm?TermID=2535 |title=gain twist |publisher=MidwayUSA GunTec Dictionary] cite web |url=http://riflebarrels.com/articles/barrel_making/rifle_barrel_accurate.htm |title=What makes a barrel accurate? |author=Dan Lilja] Extremely long projectiles such as flechettes may require impractically high twist rates; these projectiles must be inherently stable, and are often fired from a smoothbore barrel.
History
Manufacture
Most rifling is created by either:
*cutting one groove at a time with a machine tool (cut rifling or single point cut rifling);
*cutting all grooves in one pass with a special progressive broaching bit (broached rifling);
*pressing all grooves at once with a tool called a "button" that is pushed or pulled down the barrel (button rifling);
*forging the barrel over a mandrel containing a reverse image of the rifling, and often the chamber as well (hammer forging);
*flow forming the barrel preform over a mandrel containing a reverse image of the rifling (rifling by flow forming) [cite book |title=Rifling By Flow Forming |author=BARIŞ GÜN and ILHAN GÜVEL]
The grooves are the spaces that are cut out, and the resulting ridges are called "lands". These lands and grooves can vary in number, depth, shape, direction of twist ("right" or "left"), and "twist rate" (turns per unit of barrel length). The spin imparted by rifling significantly improves the stability of the projectile, improving both range and accuracy. Typically rifling is a constant rate down the barrel, usually measured by the length of travel required to produce a single turn. Occasionally firearms are encountered with a "gain twist", where the rate of spin increases from chamber to muzzle. While intentional gain twists are rare, due to manufacturing variance, a slight gain twist is in fact fairly common. Since a reduction in twist rate is very detrimental to accuracy, gunsmiths who are machining a new barrel from a rifled blank will often measure the twist carefully so they may put the faster rate, no matter how minute the difference is, at the muzzle end (see internal ballistics for more information on accuracy and bore characteristics).
Construction and operation
A barrel of circular cross-section is not capable of imparting a spin to a projectile, so a rifled barrel has a non-circular cross-section. Typically the rifled barrel contains one or more grooves that run down its length, giving it a cross-section resembling a gear, though it can also take the shape of a polygon, usually with rounded corners. Since the barrel is not circular in cross-section, it cannot be accurately described with a single diameter. Rifled bores may be described by the bore diameter (the diameter across the "lands" or high points in the rifling), or by groove diameter (the diameter across the "grooves" or low points in the rifling.) Differences in naming conventions for cartridges can cause confusion; for example, the .303 British is actually slightly larger in diameter than the .308 Winchester, because the ".303" refers to the bore diameter in inches, while the ".308" refers to the groove diameter in inches (7.70 mm and 7.82 mm, respectively.)
Despite differences in form, the common goal of rifling is to deliver the projectile accurately to the target. In addition to imparting the spin to the bullet, the barrel must hold the projectile securely and concentrically as it travels down the barrel. This requires that the rifling meet a number of tasks:
#It must be sized so that the projectile will swage or obturate upon firing to fill the bore.
#The diameter should be consistent, and must not increase towards the muzzle.
#The rifling should be consistent down the length of the bore, without changes in cross-section, such as variations in groove width or spacing.
#It should be smooth, with no scratches lying perpendicular to the bore, so it does not abrade material from the projectile.
#The chamber and crown must smoothly transition the projectile into and out of the rifling.
When the projectile is swaged into the rifling, it takes on a mirror image of the rifing, as the lands push into the projectile in a process called "engraving". Engraving takes on not only the major features of the bore, such as the lands and grooves, but also minor features, like scratches and tool marks. The relationship between the bore characteristics and the engraving on the projectile are often used in forensic ballistics.
Fitting the projectile to the bore
The original firearms were loaded from the muzzle by forcing a ball from the muzzle to the breech. Whether using a rifled or smooth bore, a good fit was needed to seal the bore and provide the best possible accuracy from the gun. To ease the force required to load the projectile, these early guns used an undersized ball, and a patch made of cloth, paper, or leather to fill the "windage" (the gap between the ball and the walls of the bore.) The patch provided some degree of sealing, kept the ball seated on the charge of black powder, and kept the ball concentric to the bore. In rifled barrels, the patch also provided a means to transfer the spin from the rifling to the bullet, as the patch is engraved rather than the ball. Until the advent of the hollow-base Minié ball, which obturates upon firing to seal the bore and engage the rifling, the patch provided the best means of getting the projectile to engage the rifling. [cite book |title=The Complete Blackpowder Handbook: The Latest Guns and Gear |author=Sam Fadala |publisher=Gun Digest |year=2006 |isbn=0896893901 Chapter 18, The Cloth Patch]
In breech-loading firearms, the task of seating the projectile into the rifling is handled by the "throat" of the chamber. Next is the "freebore", which is the portion of the throat down which the projectile travels before the rifling starts. The last section of the throat is the "throat angle", where the throat transitions into the rifled barrel.
The throat is usually sized slightly larger than the projectile, so the loaded cartridge can be inserted and removed easily, but the throat should be as close as practical to the groove diameter of the barrel. Upon firing, the projectile expands under the pressure from the chamber, and obturates to fit the throat. The bullet then travels down the throat and engages the rifling, where it is engraved, and begins to spin. Engraving the projectile requires a significant amount of force, and in some firearms there is a significant amount of freebore, which helps keep chamber pressures low by allowing the propellant gases to expand before being required to engrave the projectile. Best accuracy, however, is typically provided with a minimum of freebore, maximizing the changes that the projectile will enter the rifling without distortion. [cite book |title=Handbook for Shooters & Reloaders Volume II |author=P. O. Ackley |publisher=Plaza Publishing |year=1966 pages 97-98] [cite web |url=http://www.riflebarrels.com/articles/50calibre/throats_50_bmg.htm |title=Thoughts on Throats for the 50 BMG |author=Daniel Lilja]
Twist rate
For best performance, the barrel should have a twist rate sufficient to stabilize any bullet that it would reasonably be expected to fire, but not significantly more. Large diameter bullets provide more stability, as the larger radius provides more gyroscopic inertia, while long bullets are harder to stabilize, as they tend to be very backheavy and the aerodynamic pressures have a longer "lever" to act on. The slowest twist rates are found in muzzleloading firearms meant to fire a round ball; these will have twist rates as low as 1 in convert|60|in|mm, or slightly longer, although for a typical multi-purpose muzzleloader rifle, a twist rate of 1 in convert|48|in|mm is very common. The M16A2 rifle, which is designed to fire the SS109 bullet, has a 1 in convert|7|in|mm|sing=on twist. Civilian AR-15 rifles are commonly found with 1 in convert|12|in|mm for older rifles and 1 in convert|9|in|mm for most newer rifles, although some are made with 1 in convert|7|in|mm twist rates, the same as used for the M16. Rifles, which generally fire longer, smaller diameter bullets, will in general have higher twist rates than handguns, which fire shorter, larger diameter bullets.
George Greenhill, a mathematician at Emmanuel College, Cambridge, UK, developed a rule of thumb for use in calculating twist rates for a given lead-core bullet. The formula, named the "Greenhill Formula" in his honour, is:
$Twist = frac\left\{C D^2\right\}\left\{L\right\} imes sqrt\left\{frac\left\{SG\right\}\left\{10.9$
where:
*C = 150 (use 180 for muzzle velocities higher than 2,800 f/s)
*D = bullet's diameter in inches
*L = bullet's length in inches
*SG = bullet's specific gravity (10.9 for lead-core bullets, which cancels out the second half of the equation)
The original value of C was 150, which yields a twist rate in inches per turn, when given the diameter D and the length L of the bullet in inches. This works to velocities of about 840 m/s (2800 ft/s); above those velocities, a C of 180 should be used. For instance, with a velocity of 600 m/s (2000 ft/s), a diameter of convert|0.5|in|mm and a length of convert|1.5|in|mm, the Greenhill formula would give a value of 30, which means 1 turn in convert|30|in|mm.
If an insufficient twist rate is used, the bullet will begin to yaw and then tumble; this is usually seen as "keyholing", where bullets leave elongated holes in the target as they strike at an angle. Once the bullet starts to yaw, any hope of accuracy is lost, as the bullet will begin to veer off in random directions as it precesses.
Conversely, too-high a rate of twist can also cause problems. The excessive twist can cause accelerated barrel wear, and also induce a very high spin rate which can cause high-velocity projectiles to disintegrate in flight. A higher twist than needed can also cause more subtle problems with accuracy: Any inconsistency within the bullet, such as a void that causes an unequal distribution of mass, may be magnified by the spin. Undersized bullets also have problems, as they may not enter the rifling exactly concentric and coaxial to the bore, and excess twist will exacerbate the accuracy problems this causes. Lastly, excessive spinning causes a reduction in the lateral kinetic energy of a projectile, thereby reducing its destructive power (the energy instead becomes rotational kinetic energy).
Recent developments
The grooves most commonly used in modern rifling have fairly sharp edges. More recently, polygonal rifling, a throwback to the earliest types of rifling, has become popular, especially in handguns. Polygonal barrels tend to have longer service lives because the reduction of the sharp edges of the land reduces erosion of the barrel. Supporters of polygonal rifling also claim higher velocities and greater accuracy. Polygonal rifling is currently seen on pistols from Heckler & Koch, Glock and Kahr Arms, as well as the Desert Eagle.
For tanks and artillery pieces, the extended range, full bore concept developed by Gerald Bull for the GC-45 howitzer reverses the normal rifling idea by using a shell with small fins that ride in the grooves, as opposed to using a slightly oversized projectile which is forced into the grooves. Such guns have achieved significant increases in muzzle velocity and range. Examples include the South African G5 and the German PzH 2000.
ee also
*Rifle
*Smoothbore
*Comparison microscope
References
* [http://www.lasc.us/RangingShotBarrelMakingFeature.htm Article] on barrel making from an IHMSA shooter
* [http://www.macdor.com/technical_documents/Rifling_By_Flow_Forming.pdf Rifling By Flow Forming] A new developed method for rifling.
* [http://riflebarrels.com/articles/barrel_making/making_rifle_barrel.htm Article] on barrel making from Lilja, a maker of world class competition barrels
* [http://www.riflebarrels.com/articles/barrel_making/twist_machine.htm Article] on making and measuring rifling by Lilja; includes pictures of button rifling machine
* [http://www.6mmbr.citymaker.com/barrelFAQ.html 6mmBR article] on barrels
* [http://7.62x54r.net/MosinID/MosinSlug.htm Bore slugging tutorial] , explaining now to determine the true bore and groove size and choose appropriate bullet diameters
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Look at other dictionaries:
• Rifling — Ri fling, n. (a) The act or process of making the grooves in a rifled cannon or gun barrel. (b) The system of grooves in a rifled gun barrel or cannon. [1913 Webster] {Shunt rifling}, rifling for cannon, in which one side of the groove is made… … The Collaborative International Dictionary of English
• rifling — [rīf′liŋ] n. 1. the cutting of spiral grooves on the inside of a gun barrel to make the projectile spin when fired, thus giving the shot greater accuracy and distance 2. a series or system of such grooves … English World dictionary
• rifling — noun a) The act or process of making the grooves in a rifled cannon or gun barrel. b) The system of grooves in a rifled gun barrel or cannon. Shunt rifling, rifling for cannon, in which one side of the groove is made deeper than the other, to… … Wiktionary
• Rifling — Rifle Ri fle, v. t. [imp. & p. p. {Rifled}; p. pr. & vb. n. {Rifling}.] [F. rifler to rifle, sweep away; of uncertain origin. CF. {Raff}.] 1. To seize and bear away by force; to snatch away; to carry off. [1913 Webster] Till time shall rifle… … The Collaborative International Dictionary of English
• rifling — noun Date: 1797 1. the act or process of making spiral grooves 2. a system of spiral grooves in the surface of the bore of a gun causing a projectile when fired to rotate about its longer axis … New Collegiate Dictionary
• rifling — rifling1 /ruy fling/, n. 1. the act or process of cutting spiral grooves in a gun barrel, pipe, etc. 2. the system of spiral grooves so cut. [1790 1800; RIFLE1 + ING1] rifling2 /ruy fling/, n. the act or process of ransacking or robbing. [RIFLE2… … Universalium
• rifling — ri·fling || raɪflɪŋ n. cutting of grooves in the barrel of a firearm; grooves in the barrel of a firearm ri·fle || raɪfl n. firearm with spiral grooves carved inside the gun barrel (causes the bullet to spin and improves accuracy) v. steal … English contemporary dictionary
• rifling — noun spiral grooves on the inside of a rifle barrel … English new terms dictionary
• rifling — ri•fling [[t]ˈraɪ flɪŋ[/t]] n. 1) the cutting of spiral grooves in a gun barrel, pipe, etc 2) the system of grooves so cut • Etymology: 1790–1800 … From formal English to slang
• rifling — /ˈraɪflɪŋ/ (say ruyfling) noun 1. the act or process of cutting spiral grooves in a gun barrel, etc. 2. the system of spiral grooves so cut. {rifle1 + ing1} … Australian English dictionary | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 1, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6902675628662109, "perplexity": 5484.924324512193}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-05/segments/1579250592636.25/warc/CC-MAIN-20200118135205-20200118163205-00125.warc.gz"} |
https://admin.clutchprep.com/organic-chemistry/practice-problems/24558/major-product-of-the-following-reaction-is-160-1 | # Problem: Major product of the following reaction is:
###### Problem Details
Major product of the following reaction is: | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9643661379814148, "perplexity": 9808.938852841791}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-24/segments/1590347407001.36/warc/CC-MAIN-20200530005804-20200530035804-00214.warc.gz"} |
https://link.springer.com/article/10.1007/s11573-018-0897-5 | , Volume 88, Issue 5, pp 617–642
# Anticipating acceptance of emerging technologies using twitter: the case of self-driving cars
• Christopher Kohl
• Marlene Knigge
• Markus Böhm
• Helmut Krcmar
Open Access
Original Paper
## Abstract
In an early stage of developing emerging technologies, there is often great uncertainty regarding their future success. Companies can reduce this uncertainty by listening to the voice of customers as the customer eventually decides to accept an emerging technology or not. We show that risk and benefit perceptions are central determinants of acceptance of emerging technologies. We present an analysis of risk and benefit perception of self-driving cars from March 2015 until October 2016. In this period, we analyzed 1,963,905 tweets using supervised machine learning for text classification. Furthermore, we developed two new metrics, risk rate (RR) and benefit rate (BR), which allow analyzing risk and benefit perceptions on social media quantitatively. With our results, we provide impetus for further research on acceptance of self-driving cars and a methodological contribution to acceptance of emerging technologies research. Furthermore, we identify crucial issues in the public perception of self-driving cars and provide guidance for the management of emerging technologies to increase the likelihood of their acceptance.
## Keywords
Acceptance Benefit perception Risk perception Self-driving cars Text mining Voice of customer
C38 M30 O33
## 1 Introduction
The evolution of transportation has faced numerous trials as it has grown and expanded over time. It seems safe to assume that this steady chain of development of faster and safer vehicles with improved technological features continues (e.g., Burns 2013). Over the past decade, a vast amount of research has been conducted regarding the topic of self-driving cars (Fagnant and Kockelman 2015; Kyriakidis et al. 2015), which are being vigorously pursued by companies in the automotive and related industries. Even native IT companies such as Google are pursuing the development of self-driving cars (Spinrad 2014). However, for a technology to be successful, we must remember a significant key factor for the success of emerging technologies, technology acceptance (Davis et al. 1989).
In recent years, self-driving cars have become a controversially discussed topic. Ethical, regulatory, and liability concerns (Zmud and Sener 2017; Gogoll and Müller 2017), centering on who is driving and who assumes responsibility for accidents, are hotly debated issues. Nevertheless, the automotive and related industries seem convinced that self-driving cars will be the future of mobility and may underestimate the public’s concerns and misconceptions related to this emerging technology (Piao et al. 2016) that often differ from the perceptions of experts (Blake 1995). With the first intelligent vehicle handling systems, a pre-stage of technologies that enable self-driving cars, Conover (1994) already discussed that risk and benefit perceptions could be an issue. Research regarding other technologies also shows that risk and benefit perceptions are central determinants of their public acceptance (Siegrist 2000; Butakov and Ioannou 2015). Public perceptions, therefore, eventually determine whether self-driving cars will be used and, thus, are a crucial factor that needs to be considered especially for initial acceptance of emerging technologies such as self-driving cars (Butakov and Ioannou 2015; Pendleton et al. 2015; Bansal et al. 2016).
However, studies addressing public perception and acceptance of this emerging technology, especially across several countries and its change over time, remain scarce. We address this paucity of research by first outlining the results of previous research on public perception and acceptance of self-driving cars. Second, we describe a new approach to measure and react to public perceptions facilitating the voice of the customer (VOC). This approach gives us the opportunity to utilize the vast amounts of data publicly available in social media to anticipate acceptance of emerging technologies and answer the following research questions:
RQ1: How can we measure public perceptions of self-driving cars to anticipate acceptance?
RQ2: How do events influence the public perception of self-driving cars?
To address these research questions, we created an approach for automatically determining and monitoring perceived risks and benefits of emerging technologies from short 140-character text messages published on the social media platform Twitter. We build on scientific literature and text mining methods, which allow the extraction of knowledge from text documents (Tan 1999) and, more specifically, sentiment analysis (Hopkins and King 2010). We use the social media platform Twitter to collect a stream of opinions about self-driving cars, one instance of currently emerging technology. Based on the perceived risks and benefits of self-driving cars, we identify events and issues crucial for the future acceptance of this emerging technology and guide the management of emerging technologies.
The remainder of this paper is structured as follows: First, we provide an overview of current literature on technology acceptance, self-driving cars, and previous research on the acceptance of self-driving cars. Second, we describe the data extraction from Twitter, the preprocessing of the data, and the model generation including its evaluation. Third, we describe and discuss the results of extracting the relevant data and applying our machine learning model to this data. We conclude with a summary of the results, limitations of our work, possibilities for further research, and the contributions to research and practice.
## 2 Theoretical background
In this section, we provide an overview of current literature disclosing the significance of acceptance towards self-driving cars from both an Information Systems (IS) and public acceptance perspective. An introduction to self-driving cars, the current scientific knowledge about them, and studies assessing the acceptance of self-driving cars are presented as well. We conclude this section by summarizing the theoretical background for our study.
### 2.1 Technology acceptance
Technology acceptance is one of the main research streams of IS research. The technology acceptance model (TAM) originates from this research stream and is a crucial source of numerous research endeavors (Venkatesh et al. 2007). TAM explains and predicts if and why IS will be used by individuals using three basic constructs: perceived usefulness, perceived ease of use, and behavioral intention to use the system under consideration (Davis et al. 1989). Perceived usefulness is defined as the probability that a specific IS increases the user’s performance for a given task. Perceived ease of use describes the effort a user expects when using the IS to solve a given task. The main hypotheses of TAM are that perceived usefulness and perceived ease of use determine the strength of the behavioral intention of using a specific IS to solve a given task (Davis 1989). Behavioral intention then leads to actual use as described in the Theory of Reasoned Action (Fishbein and Ajzen 1975), an influential theory from social psychology on which TAM is based (Davis et al. 1989).
Several researchers have extended TAM to consider the importance of risk perception for user acceptance (Venkatesh et al. 2016). For example, Martins et al. (2014) study internet banking adoption and conclude that risk perception is an important factor. They found that privacy risk and the risk of being subject to Internet banking fraud are important for Internet banking acceptance. Lancelot Miltgen et al. (2013) study end-user acceptance of biometrics and find that privacy risk is important for acceptance of biometrics. These studies show that assessing risk perception requires domain knowledge to identify risks that are relevant to a certain technology. However, despite some studies including risk perception as an additional factor, it has not been included in any of the central IS acceptance models (Venkatesh et al. 2016). Risk perception depends on the emerging technology itself and, therefore, is difficult to determine with standardized questionnaire items, as it is usually the case with TAM-based acceptance research.
Public acceptance research recognizes the central role of risk perception for acceptance. Previous research shows that many technologies have been rejected by people because of societal controversies, causing negative consequences for the commercialization of technologies (Gupta et al. 2012). Considering the vast investments in research and development of self-driving cars and the potential benefits of this technology for society, rejection of this technology could have severe consequences. The events and accidents that were recently reported with self-driving cars, such as the first human casualty (Yadron and Tynan 2016), could lead to fear and reluctance to accept, let alone try out this new technology (Hohenberger et al. 2016, 2017). Even traditional automotive companies, who are investing in research and development of self-driving cars, may suffer serious damage. If the technology failed to find wide acceptance, they would not get sufficient return on their investments.
Besides the research in the IS field, there is an influential model of technology acceptance in the public acceptance field proposed by Siegrist (2000). It specifically focuses on the relationship between perceptions of risks and benefits, trust, and public acceptance. Siegrist (2000) found that trust influences perceptions of risks and benefits, which in turn directly influence technology acceptance. To understand their model, it is important to differentiate between actual risks and benefits and their perceptions. The seminal work of Slovic (1987) describes the perception of risks associated with emerging technologies that are unfamiliar and incomprehensible to most people. People rely on intuitive judgments based on media reports rather than technologically sophisticated analyses to assess the risks more objectively. These judgments are often prone to biases caused by heuristics that may not lead to optimal or rational decisions as described in prospect theory (Kahneman and Tversky 1979). Furthermore, the perception of risk and benefits is confounded (Alhakami and Slovic 1994), which means that people do not differentiate between risks and benefits when evaluating new technology. Thus, we cannot expect people to make rational decisions based on facts but rather consider their perceptions when anticipating their behavior. These perceptions are also influenced by trust, which helps people reduce cognitive complexity when evaluating new technologies (Earle and Cvetkovich 1995). Instead of their evaluation, people trust other entities to evaluate and apply emerging technologies correctly. In the case of self-driving cars, this could be the trust of people in regulatory authorities and the law to ensure that self-driving cars are safe to use (Choi and Ji 2015).
Risks and benefits of an emerging technology perceived by laypeople may vary significantly from the risks and benefits determined by experts. Emerging technologies and products, in particular, may cause anxiety and resistance to using them (Bongaerts et al. 2016; Zmud et al. 2016). Emerging technologies such as nanotechnology and genetically modified food struggle for acceptance, even if the benefits outweigh the risks from a scientific perspective, because of subjective (mis)perceptions (Gupta et al. 2012, 2015). Identifying perceived risks and benefits in an early product development stage, as it currently is the case with self-driving cars, allows companies to counteract precociously; that is, to adjust their products or product communication to address perceived risks and to exploit perceived benefits.
For anticipating and explaining technology acceptance, both IS and public acceptance research mainly rely on questionnaires. A questionnaire usually consists of several items for each construct (e.g., behavioral intention to use new technology), which were validated in prior research and adapted to the domain of application (e.g., telecommunication, banking) (Venkatesh et al. 2003). The questionnaire is then administered to a sample of the population and analyzed using regression or structural equation modeling after the data collection. This time-consuming and laborious approach comes with limitations. For example, an artifactual covariance between measures is caused by common methods, which can cause inflation of observed correlations (Sharma et al. 2009). Artifactual covariance is a major validity threat for IS acceptance as well as general social sciences research, which is often based on surveys (Sharma et al. 2009).
### 2.2 Self-driving cars
Driving automation, as in the case of self-driving cars, can be categorized into different levels of automation. There are three commonly used definitions of these levels. The German Federal Highway Research Institute (BASt) defines four levels of driving automation (Gasser and Westhoff 2012), the US National Highway Traffic Safety Administration (NHTSA) defines five levels of automation (NHTSA 2013), and the Society of Automotive Engineers (SAE) defines six levels of automation (SAE International 2014). Besides the different number of levels of automation, the definitions are similar. Kyriakidis et al. (2015) provide a comparison of the three definitions. We use the NHTSA definition to elaborate the different levels of automation exemplarily.
The idea of all definitions is to differentiate between driving automation systems providing no automation, systems providing only driving assistance, up to systems providing full automation. Table 1 summarizes the levels of driving automation. Current driving automation systems, such as Tesla’s Autopilot, require that drivers are in control of the car at any time and regardless of the current conditions. Hence, they need to be considered advanced driver-assistance systems (ADAS) that only provide level 2 driving automation according to the NHTSA definitions. However, the term “self-driving” is commonly associated with these cars. To emphasize when we specifically refer to level 4 automation, we use the term “full self-driving” in this paper.
Table 1
Levels of driving automation (NHTSA 2013)
Level
Description
Level 0: non-autonomous
The driver is in complete control of the vehicle
Level 1: function specific automation
Automation involves only specific control functions (e.g., pre-charged brakes, electronic stability control)
Level 2: combined function automation
Automation of two primary control functions to work in unison (e.g., lateral and longitudinal control, to relieve driver of control of these functions)
Level 3: limited self-driving automation
The driver has the choice to give up control of all safety–critical functions under certain conditions, yet the driver is expected to be available for occasional control
Level 4: full self-driving automation
The vehicle has full control of all safety–critical driving functions under all conditions. The driver’s availability is completely unnecessary
The major drawback of current driving automation systems is that the driver must be able to take control of driving at any time (e.g., Yadron and Tynan 2016). Drivers are misusing those systems for example by leaving the driver’s seat while driving on public roads using a level 2 driving automation system (Krok 2015). Considering how difficult it is for the driver to get back in the loop and properly react to certain traffic situations (Gold et al. 2013; Körber et al. 2016), such reports are troubling. They show that exaggerated benefit perceptions can have negative implications for driving safety and, thus, public acceptance.
A survey of public opinion about self-driving cars in the U.S., the U.K. and Australia with 1,533 respondents indicates that 56% of people have positive opinions towards self-driving cars while 13.8% express negative concerns and 29.4% are neutral towards the topic (Schoettle and Sivak 2014). The Consumer Technology Association (CTA) stated that 70% of drivers in the U.S. expressed interest in testing a self-driving car, and more than 60% of drivers showed a willingness in replacing their cars or trucks with a completely self-driving vehicle (Markwalter 2015). A study among 421 French drivers showed that 68.1% would be willing to use self-driving cars (Payre et al. 2014). Supporters argue that since 93% of car accidents are due to driver errors (Treat et al. 1977), the use of self-driving cars could reduce car accidents by that exact amount (Markwalter 2015; Fagnant and Kockelman 2015). However, opponents of this view state that self-driving cars might introduce new and currently unknown risks such as system failures or offsetting behaviors. Schoettle and Sivak (2014) concluded that self-driving cars may be no safer than an average driver and that they may increase the number of total vehicle accidents if self- and human-driven vehicles use the same roads.
In general, surveys show that people are accepting self-driving cars (e.g., Fraedrich et al. 2016) although they know only little about them. Previous research indicates that benefit perception positively influences technology acceptance (Hohenberger et al. 2017). However, focusing only on the benefits of self-driving cars might not be a sustainable strategy to increase their initial acceptance. If self-driving cars become widely available, people may begin to recognize potential safety issues and risks when they use them as in the case of active cruise control. When active cruise control was introduced in production vehicles, people began to recognize their loss of control, resulting in a lack of acceptance (Eckoldt et al. 2012). Therefore, car manufacturers need to communicate risks and limitations of self-driving cars. Misconceptions about both risks and benefits need to be avoided or even counteracted.
### 2.3 Summary
Currently, developers and manufacturers of full self-driving cars are racing to be the first ones on the market. They see the enormous potential of this emerging technology and the technological challenges, but they forget about the acceptance of customers (Rogers 2003). The prevalent method to measure acceptance is administering questionnaires, which might not be suitable for emerging technologies such as self-driving cars. Respondents to an acceptance questionnaire probably neither have detailed knowledge nor experience regarding self-driving cars, leading to biased results (Fraedrich and Lenz 2014). Rather than using standardized questionnaires, exploratory and qualitative research should be conducted in this field at an early stage (König and Neumayr 2017).
The voice of future customers provides interesting research opportunities for emerging technologies (Griffin and Hauser 1993). The risk and benefit perceptions of future customers are likely to play a central role in the acceptance of self-driving cars (Ward et al. 2017). Even before public availability, risk and benefit perceptions should be closely monitored to identify any issues with an emerging technology or its public perception. Previous research has conducted qualitative exploratory analyses of textual data about risk and benefit perceptions of self-driving cars and shown that this is a promising approach (Fraedrich and Lenz 2014; Bazilinskyy et al. 2015). The respective researchers put considerable effort in the manual coding of all data but struggled with this “cumbersome and time- consuming process” (Bazilinskyy et al. 2015, p. 2450), which still “could be biased” (Bazilinskyy et al. 2015, p. 2450). Furthermore, they suggest studying perceptions over time as they are likely to change as people become more familiar with this technology (Kauer et al. 2012; Haboucha et al. 2017; König and Neumayr 2017). In this context, it would be particularly interesting to study the effect of critical incidents with self-driving cars on public perceptions (Woisetschläger 2016). To address these findings and suggestions of previous research, we address the following propositions to answer our research questions:
P1: Machine learning algorithms can be used to analyze the publics’ risk and benefit perceptions regarding self-driving cars on Twitter.
P2a: News concerning the benefits of self-driving cars (e.g., increased safety, reduced mobility costs) increases benefit perception of self-driving cars on Twitter.
P2b: News concerning the risks of self-driving cars (e.g., accidents, hacker attacks) increases risk perception of self-driving cars on Twitter.
## 3 Method
We use a novel approach to identify risks and benefits by analyzing the vast amount of existing data about self-driving cars on Twitter encoded in tweets. This approach is theoretically founded in the quantitative content analysis (Neuendorf 2016), which allows conducting quantitative data analyses based on qualitative data and extends previous qualitative approaches (Fraedrich and Lenz 2014; Bazilinskyy et al. 2015). While content analysis has been used to analyze mainly unstructured social media before (e.g., McCorkindale 2010), we automate most of the coding process using machine learning. This method is similar to sentiment analysis in marketing research (Okazaki et al. 2014) and has the advantage that only a small portion of the data needs manual coding when using supervised machine learning classification. By using this method, we avoid certain issues with questionnaires and studying technology acceptance, for example, common method variance (Sharma et al. 2009).
We follow the analysis process suggested by Okazaki et al. (2014) for sentiment analysis. It consists of data extraction, data preparation, model generation, model validation, and model application. Our approach to risk and benefit perception analysis is similar to sentiment analysis, which allows us to follow a common sentiment analysis process. Variations in the sentiment analysis process, for example, combining the steps of model generation and validation into one step (Feldman 2013) usually do not differ much.
We implemented the process of Okazaki et al. (2014) as follows: First, we obtain tweets using the Twitter Search API (data extraction). Second, we preprocess the tweets to improve data quality, reduce dimensionality, and avoid misclassification (data preparation). Third, we train the machine learning algorithm (model generation) and evaluate it using cross-validation (model validation). Fourth, we apply the machine learning algorithm to classify the tweets (model application). We then analyze the classified tweets qualitatively and quantitatively to address our research propositions.
Twitter has often proven to be a valuable source of data for prediction and monitoring of diverse phenomena ranging from disease outbreaks (St Louis and Zorlu 2012) to political elections (Tumasjan et al. 2010). Users of Twitter face a limit of 140 characters per message, referred to as “tweet,” to include all relevant information. Despite their brevity, tweets contain valuable information encoded in natural language (Pak and Paroubek 2010). It is an ongoing challenge to extract this information from the vast amount of noise present on Twitter. We build on previous findings from sentiment analysis (Pak and Paroubek 2010) and machine learning classification to extract information from tweets. We need to extend previous approaches, as sentiment analysis is not directly applicable to the extraction of risk and benefit perceptions. It traditionally only assigns a polarity, i.e., positive or negative sentiment, to a given statement (Medhat et al. 2014).
New developments on Twitter include Twitter bots that are difficult to discern from real persons (Boshmaf et al. 2011; Haustein et al. 2016) and Internet of Things (IoT) devices that communicate over Twitter (Kranz et al. 2010). Therefore, results of Twitter analyses require careful consideration. The Twitter bots have especially become increasingly good at emulating human communication and writing style. Researchers are concerned about the large-scale infiltration of so-called “socialbots” that are hardly discernable from humans (Boshmaf et al. 2011). Socialbots make a quantitative analysis, for example analyzing tweet counts, not only from Twitter but also other social platforms such as Facebook, challenging (Haustein et al. 2016). However, we will compare the results of our analysis with previous studies to detect manipulations of the Twitter data.
A further issue with tweets is that they are not directly accessible from the authors. We only retrieve tweets in this study that are returned by the Twitter Search API, which are determined by proprietary algorithms and are not a representative sample of the overall tweets (Ruths and Pfeffer 2014). Furthermore, Twitter users are not a representative sample of the population (Ruths and Pfeffer 2014). However, Twitter has a broad audience from different social and interest groups and, thus, is a valuable source to assess people’s perceptions (Pak and Paroubek 2010). We expect Twitter users to be more open to new technology, which could lead to slightly more positive results compared to previous surveys based on representative samples of the population.
Despite the limitations of Twitter mining, our approach allows accessing the VOC of 328 million monthly active Twitter users (Twitter 2017), which results in considerably more statements concerning the acceptance of self-driving cars than in previous research. To cope with the huge amounts of data from Twitter, we use machine learning to automate the classification of tweets. Thereby, we avoid the laborious manual coding of qualitative content, thus, making this research feasible.
### 3.2 Data extraction
Our dataset comprises tweets written in English concerning self-driving cars that were obtained using the Twitter Search API (Twitter 2016a). Furthermore, we developed a Java application as the Twitter Search API only allows retrieval of tweets not older than 1 week (Twitter 2016b). A meaningful longitudinal analysis, however, requires being able to collect tweets for longer intervals by collecting the tweets daily and storing them in a database. A MongoDB NoSQL database was used to store the complete tweets returned by the Twitter Search API including their date of creation, the username of the tweet creator, the message body, and a unique identifier of the tweet. The tweets have then been transferred to an in-memory database to process them efficiently. We used a SAP HANA database SPS10 with 1 TB RAM and 32 CPU cores. SAP HANA offers R-integration, which allowed us to process the data using external R-libraries. The R server was installed on a virtual machine connected to the SAP HANA database. We started the data collection for this analysis on March 3, 2015, with the last tweets being collected on October 21, 2016. We used the following set of search queries (SQ) in our Twitter Search API requests:
• SQ1: self driving OR driverless OR autonomous OR automated
• SQ2: tesla OR google OR apple OR icar OR ford OR opel OR gm OR general motors
• SQ3: volkswagen OR vw OR daimler OR mercedes OR benz OR bmw OR audi OR porsche.
The search queries were fixed before the data collection. They consist of a combination of topic-related keywords (SQ1), names of US-based companies working on self-driving cars and U.S. car manufacturers (SQ2), as well as German car manufacturers (SQ2 and SQ3). Especially SQ2 and SQ3 resulted in many tweets that were not concerned with self-driving cars. However, at the beginning of our research in March 2015, we wanted to make sure that the search queries would find the relevant tweets without having to change the search queries over time. In total, we collected 1,963,905 tweets. For the data analysis, the tweets were filtered using the following regular expression:
(driver.?less|self.?driving|autonomous.?driving|automated.?driving|autonomous.?car|automated.?car)
The filtering ensures that only tweets containing one of the following terms are included in the data analysis: driverless, self-driving, autonomous driving, automated driving, autonomous car, and automated car. The regular expression also ensures that slight variations of the terms are included, such as “driver less” or “driver-less.” This filtering method reduced the number of relevant tweets to 642,033. For training the machine learning classifier, we used a dataset of 7,482 manually categorized tweets ranging from the beginning of January 2010 to June 2014, which we collected by scraping the “top tweets” about self-driving cars from the Twitter website. Table 2 shows the descriptive statistics of the training dataset.
Table 2
Descriptive statistics of the training dataset
Class
Risk
Benefit
Neutral
N
751
701
6030
%
10.0
9.37
80.6
Top tweets are “popular tweets that many other Twitter users have engaged with and thought were useful” (Twitter 2016c). Analyzing those tweets, we got an overview of the discussion of this topic on Twitter, which helped to design this study. However, we refrain from analyzing these tweets since they only represent a small fraction of the actual tweets published from January 2010 to June 2014 and are probably highly biased through the proprietary selection algorithms implemented and used by Twitter. Instead we do use them as “training data” for machine learning classification. In 80.6% of the tweets in the training dataset, no information about risk and benefit perceptions was present and were, thus, categorized as “Neutral.”
### 3.3 Data preprocessing
We performed data preprocessing on the tweets to reduce dimensionality and avoid misclassification, a common step in text classification (Okazaki et al. 2014). That means we changed parts of the tweets so that the machine learning algorithm can extract relevant information from the tweets better, which results in better classification results. We use the text mining package “tm” for preprocessing, which provides a text mining framework for the statistics software R (Feinerer et al. 2008) to apply the preprocessing steps to both the training data and the tweets we want to classify automatically.
First, we transformed all characters in the body of the tweets to lower case. Like most of the preprocessing steps, this step decreases readability for humans. However, machine learning classifiers for text classification mainly rely on statistical features of the provided textual data and, thus, profit from such transformations. Second, we removed punctuation, numbers, and hyperlinks. Punctuation is not required to determine the classification of the tweets as we will not perform a grammatical analysis. Third, we removed English stop words as provided by the tm package. Stop words are terms that do not contain relevant information for the text classification (e.g., “a,” “by,” and “was”), so they are not needed in the further analysis. In addition to removing the English stop words, we removed the Twitter-specific stop words “via” and “rt.” Fourth, we used stemming to reduce the dimensionality of the tweets further. Stemming reduces words with the same stem to the same word by stripping derivational and inflectional suffixes, for example: “driving” is stemmed to “drive.”
The transformed tweets should now mainly contain words that are meaningful for machine learning classification. In the last step, we transformed the textual representation of the tweets into a document-term-matrix (DTM). In the scope of our analysis, terms are single words (i.e., unigrams). Only words that occur at least twice in the remaining set of tweets were included in the analysis. The entries in the DTM are the frequency of all terms (TF) in the tweet weighted by the inverse document frequency (IDF), i.e., how often a term occurs in the other tweets (Ramos 2003).
### 3.4 Model generation and evaluation
The basic idea of text classification with supervised machine learning is to assign classes to documents automatically using a much smaller set of training data compared to the overall number of documents to classify. The training data usually contains manually classified documents. Based on these, the machine learning algorithm creates a model that determines how to classify new documents. Many different machine learning algorithms could be used for this task such as Naïve Bayes, Maximum Entropy Classification, or Support Vector Machines (SVM) (Pang et al. 2002).
We decided to use the SVM algorithm for text classification, which has been shown to be highly effective for this task (Joachims 1998; Pang et al. 2002). It does not require extensive parameter tuning and copes well with large feature vectors as it is usually the case with text classification problems (Joachims 1998). The basic idea of SVM is to find a hyperplane that separates the documents (tweets) according to their classification with a margin that is as large as possible, which is an optimization problem (Pang et al. 2002). We use the Library for Support Vector Machines (LIBSVM) implementation of SVM that allows classification, regression, and other learning tasks in R and other programming languages (Chang and Lin 2011).
We use a linear kernel function since this is recommended for datasets consisting of many instances and features (Hsu et al. 2016). Furthermore, text classification problems are often linearly separable (Joachims 1998). For linear kernels, only one parameter of the SVM algorithm can be varied to improve the classification performance: the regularization parameter C. We tested several different values ranging from 0.03125 to 100 using 10-fold cross-validation. A k-fold cross-validation randomly splits the training data into k mutually exclusive, approximately equal sized subsets (i.e., folds) (Kohavi 1995). The algorithm uses one of the k folds to evaluate the classifier by computing the accuracy and the other k − 1 folds to train it. This step is repeated k times until each fold has been used for training and evaluation. The result of the cross-validation is the mean accuracy of all k evaluations. Accuracy is defined as the overall number of correct classifications divided by the number of instances in the dataset.
Based on the cross-validations with varying of the C-parameter, we observed that higher values of C lead to higher classification accuracy. However, higher values of C also increase the compute time of training the SVM and improved the classification accuracy only slightly after C = 64. We determined C = 94 for the SVM, which has a very high accuracy of 0.925 considering results obtained in similar studies (e.g., Sriram et al. 2010). The SVM classification also leads to much better results than classification based on hand-picked keywords (Pang and Lee 2008).
For the second evaluation, we split the training data using a random selection of 80% (N = 5984) of the tweets for training the SVM and 20% (N = 1496) for evaluating the quality of the classification. We then compute several metrics based on the confusion matrix (Table 3).
Table 3
Confusion matrix of the SVM algorithm
True class
Risk
Benefit
Neutral
Predicted class
Risk
108
4
27
Benefit
3
101
15
Neutral
45
28
1165
The accuracy of the classification was 0.918, which is close to the average accuracy of the cross-validation. We computed the “no-information rate”, the largest proportion of the observed classes, since the imbalance between the classes is large (Kuhn 2008). The no-information rate has a value of 0.807 and is significantly different (p < 0.001) from the accuracy. Additional metrics were computed according to Kuhn (2008) (Table 4).
Table 4
Metrics by class
Metric
Risk
Benefit
Neutral
Average
Sensitivity
0.69231
0.7594
0.9652
0.80564
Specificity
0.97687
0.98679
0.7474
0.90369
Pos. Pred. Value
0.77698
0.84874
0.941
0.85557
Neg. Pred. Value
0.96463
0.97676
0.8372
0.9262
Prevalence
0.10428
0.0889
0.8068
0.33333
Detection rate
0.07219
0.06751
0.7787
0.30613
Detection prevalence
0.09291
0.07955
0.8275
0.33332
Balanced accuracy
0.83459
0.8731
0.8563
0.85466
While accuracy shows very good values, we could identify issues of the classifier resulting from the imbalanced training set. For example, sensitivity for the classes “Risk” and “Benefit” and specificity for the class “Neutral” is relatively low, indicating that the classification is biased to assign the neutral class. However, for our analyses, we consider this result as a good compromise between sensitivity and specificity for all three classes.
## 4 Results
With an overall total of 642,033 tweets, we obtained 528,440 (82.3%) neutral tweets, 50,612 (7.88%) stated benefits (BT), and 62,981 (9.81%) stated risks about self-driving cars (RT). The risk ratio (RR) and benefit ratio (BR) were calculated as follows:
$${\text{RR}} = \frac{\text{RT}}{{{\text{RT}} + {\text{BT}}}} = \frac{62981}{62981 + 50612} = 0.5544$$
(1)
$${\text{BR}} = \frac{\text{BT}}{{{\text{RT}} + {\text{BT}}}} = \frac{50612}{62981 + 50612} = 0.4456 = 1 - {\text{RR}}$$
(2)
The RR describes the ratio of tweets about risks of self-driving cars to the total number of tweets excluding the neutral tweets that neither contain information about risks nor benefits. BR is defined analogously and can also be calculated as 1 − RR when RR is already known as RR + BR equals to one.
In 2015, 407,179 (83.0%) of the tweets were neutral, 37,891 (7.73%) stated benefits, and 45,214 (9.22%) stated risks about self-driving cars (Table 5). The RR in 2015 equals to 0.5441 and BR equals to 0.4559. In 2016, 121,261 (79.9%) of the tweets were neutral, 12,721 (8.38%) stated benefits, and 17,767 (11.7%) stated risks about self-driving cars. Overall, we see only slightly changing ratios over the years in our analysis.
Table 5
Number of tweets per year by class
Year
Neutral
Benefit
Risk
RR
BR
2015
407,179
83.0%
37,891
7.73%
45,214
9.22%
0.5441
0.4559
2016
121,261
79.9%
12,721
8.38%
17,767
11.7%
0.5828
0.4172
Overall
528,440
82.3%
50,612
7.88%
62,981
9.81%
0.5544
0.4456
We found a decrease of the ratio of neutral tweets, which might indicate that the SVM classifier performs consistently over time. The classifier does not fail to detect risk and benefit tweets among the huge number of neutral tweets as time progresses and topics change. Additionally, the discussion about self-driving cars might also focus more on risks and benefits of the technology as they become more known to the public.
The fact that RR and BR did not change substantially from 2015 to 2016 shows that RR and BR might be a robust measure to quantify risk and benefit perception. Closer inspection of RR shows that it did change between the months and might be an important indicator of issues in risk and benefit perception. Figure 1 shows the development of RR and BR over time.
By analyzing the tweets in detail, we can track how Twitter users react to specific news reports, announcements, or other events and whether changing perceived risks or benefits is influenced by these events. We found that there is a relationship between occurrences related to self-driving cars and the content of tweets. This finding allows us to state that, although being subjective, tweets regarding self-driving cars are related to facts and occurrences in the real world. In the following, we will give some examples.
In April 2015, we observed more tweets about benefits of self-driving cars than about risks as RR is smaller than 0.5 (Fig. 1). In this month, Google explained the use of solar energy and ridesharing for their self-driving car. Therefore, the Google Car has the potential to help protect the environment and ease congestion in major cities. Further, Google reported that their self-driving cars could reduce the number of people injured and killed in accidents. Tweets frequently discussed this report, which was one of the main reasons why in April 2015 RR was smaller than 0.5.
From May to July 2015, the tweets containing risks suddenly increased and outweighed the tweets containing benefits. The main reason for this is that Google released data showing that its self-driving cars had been involved in eleven minor accidents over the past 6 years. In June 2015, a website run by Google provided explanations for the accidents. In July 2015, Google reported its first accident with an injury. Although we have not explicitly filtered for Google-related posts, most tweets in this month were related to Google.
Evaluation of tweets from August 2015 revealed a spike in BR. We found that many tweets mentioned the announcement of self-driving crash trucks. These trucks are usually deployed on roadworks to protect the road workers from distracted drivers who would otherwise crash into them (Rubinkam 2015). Drivers of crash trucks are usually in a dangerous situation; replacing the driver with a driving automation system could save lives, which was obviously well-received by the public.
From September to October 2015, no noticeable changes in the RR occurred. In November 2015, Nevada approved regulations for self-driving cars, which lead to many tweets classified as benefit. The news that Google and Chrysler cooperated to produce self-driving cars was classified as benefit in April 2016. In June 2016, Volvo Cars & Ericsson released intelligent media streaming for self-driving cars, which lead to tweets classified as Neutral and, thus, did not influence RR.
In July 2016, the first fatal accident with the Tesla self-driving car occurred. We could detect this event in our data as it was often mentioned in tweets resulting in a spike in RR. In total, 631 risk tweets about self-driving cars were identified in our dataset compared to 352 benefit tweets.
In August 2016, Tesla announced a \$2.6 Billion deal with Solar City to combine solar energy with self-driving cars. People also tweeted about self-driving tractors that promise to work by themselves. Also, Ford announced self-driving taxis for 2021 and people started tweeting about self-driving living rooms, so nobody has to leave the sofa. However, many tweets about accidents with self-driving cars were reported in this month, resulting in a RR value of 0.5348, which shows that tweets classified as risk (N = 1269) slightly prevail over tweets classified as benefit (N = 1104).
In October 2016, tweets often mentioned that a self-driving car hit a truck in Singapore. This lead to an increased risk rate. The last tweets in the analyzed dataset were from October 21, so the analyses do not reflect events after this date.
In addition to the RR, we also inspected the absolute numbers of tweets classified as risk (Fig. 2) and benefit (Fig. 3). Plotting the tweets over time, we could observe several changes in the number of risk and benefit tweets. One characteristic month in our dataset is November 2015. A close inspection of the tweets shows that the annual International Driverless Cars Conference caused a general increase of tweets. This conference might not only have caused more tweets about self-driving cars but also led to an increased interest in reading tweets about self-driving cars, which were then retweeteda self-reinforcing effect.
By analyzing the data, we recognized that the discussion about self-driving cars is dominated by the Google Car as found in previous research (Woisetschläger 2016). In contrast to currently available self-driving cars, the Google Car offers full self-driving capability (i.e., level 4 automation). So, the driver is not required to take over control of the car at any time. News such as a blind person driving the Google Car have been tweeted very often. Figure 4 shows the total number of tweets for each car manufacturer in the dataset. As described in Sect. 3.2, we specifically queried Twitter about tweets for those car manufacturers. The dominance of US-based companies is striking. The top five companies mentioned in tweets have their headquarters in the U.S. Furthermore, it is remarkable that IT companies are linked that strongly to this topic. Apple has not even officially announced a self-driving car but is only rumored to work on such a project, the Apple Car. However, we need to acknowledge that the dataset is biased for the U.S. market since we queried Twitter only for English tweets.
## 5 Discussion
Before we discuss and interpret our results, we discuss their validity. First, we compare our findings to previous research. Fraedrich et al. (2016) found in a study conducted in Germany that 46% of their 1163 respondents had a positive connotation with self-driving cars. Schoettle and Sivak (2014) surveyed 1533 persons from the U.S., the U.K., and Australia for their opinions on self-driving vehicles and found that 56.8% of the respondents had at least a slightly positive opinion. Our BR ranges between 46% (2015) and 42% (2016), which is almost equal to the study of Fraedrich et al. (2016) and approximately 10% smaller than the rate of positive opinions from the study of Schoettle and Sivak (2014). Therefore, we are confident that our data resembles the public perceptions of risk and benefit perception and we found first support for our proposition P1 that machine learning algorithms can be used to analyze the publics’ risk and benefit perceptions regarding self-driving cars on Twitter. Second, our analysis shows that news and events were reflected in tweets as our in-depth analysis of tweets in the previous section has shown. Therefore, we also found support for our propositions P2a and P2b. In the following, we further discuss our findings and connect it to previous research on the acceptance of self-driving cars.
Given the previous study results and the RR and BR values determined in this study, we conclude that people have specific reservations regarding self-driving cars. It could be surmised that if self-driving cars were released today, technology acceptance could not be guaranteed. Public concerns need to be addressed before the public is confronted with a rising number of increasingly automated cars or even full self-driving technology. We calculated the BR and RR values at various time points to analyze the tweets over time and found an increase in RR of 7.11% from 54.4% (2015) to 58.5% (2016). This might indicate that people’s concerns have not been addressed. Furthermore, there might be a bias caused by a social amplification of risk perceptions (Kasperson et al. 1988), i.e., people tend to talk more about risks than about benefits. While it is an interesting finding that social amplification of risk perceptions might exist in social media, the results are troubling. We see in many instances that social media increasingly leads to exaggerated risk perceptions that lead to irrational behaviors. The consequence might be that one single accident could severely reduce acceptance of self-driving cars of all manufacturers and providers.
We found many tweets that indicated a distorted perception of a risk, for example, “[…] Google’s driverless cars have been involved in four car accidents” or “CAR CRASH Google Self Driving Cars to Decide if You Live or Die […]”. However, rather than increasing the number of accidents, self-driving cars could significantly reduce them (Fagnant and Kockelman 2015). Other studies also found distorted perceptions, which might change as people become more familiar with self-driving cars (Woisetschläger 2016; Bansal et al. 2016).
People also expressed distrust towards the self-driving car manufacturing companies and conveyed their love for driving. For example: “Sorry @google not going to buy a self driving car I like driving and don’t trust your technology.” In this case, benefit perception is distorted. While driving can be enjoyable in certain situations, we find ourselves often confronted with less enjoyable aspects of driving such as traffic congestion, long monotonous highways with speed limitations or searching for a parking space in increasingly crowded cities. We find these concerns also in marketing research that predicts a lack of emotional attachment due to the loss of driving pleasure when a car drives itself (Olson 2017). First studies are addressing the user experience in self-driving cars (Rödel et al. 2014; Pettersson and Karlsson 2015; Niculescu et al. 2017). Other research proposes to adapt the driving style of self-driving cars to the driving style of their users to mitigate this issue (Kraus et al. 2009; Butakov and Ioannou 2015; Kuderer et al. 2015). To mitigate trust issues and to increase driving pleasure, previous research also suggests allowing drivers to take back control of their vehicles if they like (Yap et al. 2016).
People also displayed fear for their safety and privacy, for example, “[…] Can #driverless #cars be made safe from hackers?” expresses the fear of hackers that could take control of your vehicle. Hackers might even implement viruses that could spread from car to car, a risk that could prove to be real as hacker activities have been noted on current cars and due to the increased connectedness of self-driving cars (Lee et al. 2016). These hacking attacks could cause financial and physical harm and even death to car passengers and other road users, which is certainly more severe than having a personal computer hacked. Manufacturers of self-driving cars need to be aware of hackers and provide strategies to avoid hackers successfully attacking their vehicles. Previous research shows that hacker attacks have become one of the biggest concerns about self-driving cars (Zmud and Sener 2017).
Regarding the tweets classified as containing benefits of self-driving cars, many users liked the fact that they could save time by using self-driving vehicles. For example: “Sleepy time in the car for a in back seat. Wish I had a self driving car & I coulda joined em……”. This tweet represents a case of distorted benefit perception since only full self-driving automation allows sleeping while driving. The current level of self-driving cars is level 2, and it is likely to take some years until we arrive at level 3 or even level 4 automation. Meanwhile, drivers are misusing current self-driving cars, by leaving the driver’s seat while driving on a public road using the Autopilot feature of a Tesla Model S (Krok 2015). Thereby, they, intentionally or unintentionally, risk their own and others’ lives and potentially affect acceptance of self-driving cars by the public as the fatal accident of a self-driving Tesla has shown. Manufacturers should, however, be aware that people would like to sleep while being in a self-driving car to prevent it in cars with lower automation levels and offer a comfortable interior in full self-driving cars to enable it. Several studies mention sleeping while being in a self-driving car to be a popular activity (e.g., Cosh et al. 2017).
In general, people are impressed by the innovation put into the self-driving cars. For example: “[…] That hyper-futuristic driverless Mercedes has been spotted in San Fran – again […]”. Most benefit tweets reflected that people were simply excited to try something new. For example: “[…] A perk of living near Google… We saw the self-driving car today on the highway!” Developers of self-driving cars have recognized that people are excited about this new technology and the benefits it could provide. Consequently, they are investing in the development of self-driving cars and already promise features that will only be implemented in several years. If communication strategies are not adjusted, this excitement could cause a misunderstanding of the potential benefits and exaggerated risk perceptions of self-driving cars. Focusing only on the benefits and even generating exaggerated benefit perceptions could also have adverse effects on public acceptance of self-driving cars (Nees 2016).
## 6 Conclusion
By analyzing 642,033 tweets, we could show that using machine learning to classify social media automatically is a promising approach to analyze acceptance of emerging technologies such as self-driving cars. Even if data from Twitter is prone to certain biases, our results are in line with previous research. Our approach mitigates some of the methodological shortcomings regarding data collection, time-consuming manual coding, and biases of online surveys for emerging technologies. Thereby, we follow the call by several researchers to provide new impetus for acceptance research (e.g., Benbasat and Barki 2007). Furthermore, our approach allows measuring the effect of certain events on public perception of emerging technologies. The identified perceived risks and benefits can be incorporated in traditional acceptance models for survey-based research.
Our research has several managerial implications. Based on our results, we identified the need for developers and manufacturers to listen to the voice of future potential customers. Even the objectively best solution or superior new technology development can fail if it does not appeal to the customer or does not create public acceptance. Therefore, an active management of the public acceptance is mandatory to reduce the failure rate of new technologies. In the case of self-driving cars, companies need to rethink their communication strategies to address distorted perceptions of both the benefits and risks of self-driving cars (Kasperson and Kasperson 1996), already obvious with the first available level 2 automated cars. An overestimation of benefits might lead to a misuse of self-driving cars, the disappointment of initial users, and could have fatal consequences. An overestimation of risks by the public could lead to a resistance against self-driving cars before they even become widely available (Kleijnen et al. 2009; König and Neumayr 2017). Furthermore, practitioners should make sure to exploit the full potential of self-driving cars by implementing the benefits discussed in social media as described in this paper. First field studies show that people are more accepting of self-driving vehicles after having used prototypes (e.g., Alessandrini et al. 2011; Pendleton et al. 2015; Christie et al. 2016; Portouli et al. 2017; Madigan et al. 2017). Early personal experience with prototypes may lead to less susceptibility to distorted perceptions of self-driving cars and, therefore, should be made available more publicly by, e.g., self-driving car events of manufacturers, establishing additional model regions and test tracks, or creating driving experience centers for self-driving cars. We also found that user interface design will play an important role for the next generation of level 2 and level 3 driving automation systems as the risk perception of Daimler's Intelligent Drive system shows. Rather than the increased safety due to system restrictions, users primarily perceive the increased loss of control caused by them, which could reduce acceptance.
This research has some limitations. By using machine learning algorithms other than SVM and additional training data, analyses might be further improved. However, we do not expect major improvements since our analysis of the SVM classifier performance already showed good results and SVM are usually among the strongest performers for text classification (Socher et al. 2011). Further research should rather focus on more detailed risk and benefit categories. For example, Slovic (1987) describes risks as a combination of two factors: unknown risks, which are not observable and unknown to those exposed, and dread risks, which can be globally catastrophic and fatal. Hohenberger et al. (2017) divided the benefits of self-driving cars into the sub-categories of economic, time, and safety benefits. Further research could analyze risk and benefit perceptions using sub-categories of risks and benefits or identify new categories influencing technology acceptance based on data from social media.
For further research, it could be interesting to use topic modeling (Debortoli et al. 2016) to support the in-depth qualitative analysis of the tweets after classification. A next step could be to include other social media sources into the analyses such as Facebook, Reddit, or blogs. While our Twitter sample appears to be comparable to existing survey samples, extending the analyses to other platforms would allow analyzing differences in the explication and dissemination of perceptions between social media platforms. However, this would require extending the technical platform as the structures of other social media platforms differ from Twitter significantly. Besides analyzing opinions expressed in written text, VOC can also be extracted from other media such as recorded speech and videos, as mentioned by Brown (2017), who analyzed YouTube videos about experiences with driving automation. Including diverse sources may lead to a broader overview of opinions and perceptions and helps to improve our understanding of the various aspects of emerging technologies, which are relevant for potential customers and society.
## Notes
### Acknowledgements
We greatly appreciate the feedback from three anonymous reviewers who helped us improve and refine our paper. This work was partly performed within the Munich Center for Technology in Society (MCTS) lab “Automation & Society: The Case of Highly Automated Driving” as part of the Excellence Initiative by the German Research Foundation (DFG) and the TUM Living Lab Connected Mobility (LLCM) funded by the Center Digitization.Bavaria (ZD.B) and the Bavarian Ministry of Economic Affairs and Media (StMWi). We thank the Future SOC Lab of the Hasso-Plattner-Institute (HPI) for providing us a SAP HANA database and the computing resources necessary for this research. Support for this research was also provided by the TUM Center for Doctoral Studies in Informatics and its Applications (CeDoSIA). The TUM Chair for Information Systems’ Center for Very Large Business Applications (CVLBA) allowed us to provide open access to this paper. An early version of this analysis was presented at the WI 2017 conference.
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## Authors and Affiliations
• Christopher Kohl
• 1
• Marlene Knigge
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https://www.lebesgue.fr/content/5min-program | • English
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• Conference - Dynamics on representation varieties
Jun 26, 2017 to Jun 30, 2017
Rennes, from June 26th to June 30th
Organization board: Ian Biringer, Ludovic Marquis, Juan Souto
Scientific board: Uri Bader, Jeffrey F. Brock, Jean-Marc Schlenker
Numerous areas of mathematics are touched by what could be called Dynamics on representation varieties. For instance one could mention ergodic theory, Riemannian geometry, low-dimensional topology, Teichmüller theory, and so on... The aim of this workshop is to bring together graduate students, recent graduates and experts in these different areas, giving everybody ample time for discussions and collaborations. Next to a number of research talks, three mini-courses by Tsachik Gelander, Francois Labourie and Julien Marché will take place.
We the organizers of this conference affirm that scientific events must be open to everyone, regardless of race, sex, religion, national origin, sexual orientation, gender identity, disability, age, pregnancy, immigration status, or any other aspect of identity. We believe that such events must be supportive, inclusive, and safe environments for all participants. We believe that all participants are to be treated with dignity and respect. Discrimination and harassment cannot be tolerated. We are committed to ensuring that the Conference Dynamics on representation varieties follows these principles. For more information on the Statement of Inclusiveness, see this dedicated web page.
• School - Analytical aspects of hyperbolic flows
Jul 3, 2017 to Jul 7, 2017
Nantes, from July 3rd to July 7th
Organization board: Sebastien Gouëzel, Laurent Guillopé, Samuel Tapie
Scientific board: Nalini Anantharaman, Viviane Baladi, Colin Guillarmou, Masato Tsujii
Hyperbolic flows are dynamical systems with strong chaotic properties, whose study has been started a long time ago, a crucial example being the geodesic flow on negatively curved manifolds. Whereas the qualitative properties of such flows are well understood, their fine quantitative properties (rate of mixing, spectrum...) require more sophisticated tools. They have been studied both from a dynamical point of view (Dolgopyat's techniques) and more analytically: semi-classical methods, initially introduced to study PDEs, have proven very valuable in this context.
The purpose of this summer school is to make these different techniques accessible to PhD students and young researchers, as well as to give an opportunity for specialists in dynamical systems to learn tools from semi-classical analysis, and conversely. Therefore, the core of this summer school will consist in three introductive mini-courses, completed by a few research talks and question sessions.
Conference brochure
• Conference - Young researcher meeting in dynamics and geometry
Sep 6, 2017 to Sep 8, 2017
Rennes, from September 6th to September 8th
Organization board: Françoise Dal'Bo, Frédéric Paulin, Barbara Schapira, Damien Thomine
Since its creation the Platon network (GDR National Center for Scientific Research n°3341 http: // costia.free.fr / platon/) leads actions towards young researchers in ergodic geometry. The recurrent young researcher meeting is one of the highlights of the year. The goal is to allow about ten PhD students or recent doctors to expose their work and promotes discussions between young and senior researchers. The "Young researcher meeting in dynamics and geometry" follows the spirit of these recurring meetings with an international dimension brought in particular by Swiss and Senegalese networks.
TALKS
Alexander Adam (UPMC) Resonances for Anosov diffeomorphism
Kamel Belarif (Université de Bretagne Occidentale) Genericity of weak mixing in negative curvature
Adrien Boulanger (UPMC) Cascades in affine interval exchanges
Filippo Cerocchi (Max Planck Institute for Mathematics, Bonn) Rigidity and finiteness for compact 3-manifolds with bounded entropy
Maria Cumplido Cabello (Université de Rennes 1) Loxodromic actions of Artin-Tits groups
Nguyen-Bac Dang (Ecole Polytechnique) Degrees of iterates of rational maps
Laurent Dufloux (Oulu University) Hausdorff dimension of limit sets at the boundary of the complex hyperbolic plane
Mikolaj Fraczyk (Université Paris-Sud) Mod p homology growth of locally symmetric spaces
Weikun He (Université Paris-Sud) Sum-product estimates and equidistribution of toral automorphisms
Cyril Lacoste (Université de Rennes 1) Dimension rigidity of lattices in semisimple Lie groups
Erika Pieroni (Università di Roma, Sapienza) Minimal Entropy of 3-manifolds
Fanni M. Selley (Budapest University of Technology) Ergodicity breaking in mean-field coupled map systems
Nasab Yassine (Université de Bretagne Occidentale) Quantitative recurrence of one-dimensional dynamical systems preserving an infinite measure
ABSTRACTS
• Alexander Adam Resonances for Anosov diffeomorphism
The deterministic chaotic behavior of an invertible map T is appropriately described by the existence of expanding and contracting directions of the differential of T. A special class of such maps consist in Anosov diffeomorphisms. Every 2-by-2 hyperbolic matrix M with integer entries induces such a diffeomorphism on the 2-torus. For all pairs of real-analytic functions on the 2-torus, one defines a correlation function for T which captures the asymptotic independence of such a pair under the evolution T^n as n tends to infinity. What is the rate of convergence of the correlation as n tends to infinity, for instance what is its decay rate? The resonances for T are the poles of the Z-transform of the meromorphic continued correlation function. The decay rate is well-understood if T=M. There are no non-trivial resonances of M. In this talk, I consider small real-analytic perturbations T of M where at least one non-trivial resonance of T appears. This affects the decay rate of the correlation.
• Kamel Belarif Genericity of weak mixing in negative curvature
Let M be a manifold with pinched negative sectional curvature. We show that, when M is geometrically finite and the geodesic flow on T^1M is topologically mixing, the set of mixing invariant measures is dense in the set P(T^1M) of invariant probability measures. This implies that the set of weak-mixing measures which are invariant by the geodesic flow is a dense G-delta subset of P(T^1M). We also show how to extend these results to geometrically infinite manifolds with cusps or with constant negative curvature.
• Adrien Boulanger Cascades in affine interval exchanges
Avec un échange d'intervalle affine donné vient naturellement une famille de telles dynamiques indexées par le cercle. En effet, la pré-composition par une rotation de l'application initiale définit un autre échange d'intervalle affine. On étudiera cette famille de dynamiques dans un cas particulier à travers la géométrie de la surface affine associée et son groupe de transformation affine.
An affine interval exchange (AIE) is a piecewise affine map from the circle to itself. Such a map defines a dynamical systems over the circle by iterating it. With an AIE comes naturally a family of AIE indexed by the circle: they are defined by pre-composing the initial AIE by a rotation. The presentation will focus on the study of possible dynamical behaviors of such a family of AIE through a peculiar example.
• Filippo Cerocchi Rigidity and finiteness for compact 3-manifolds with bounded entropy
We present some local topological rigidity results for the set S of non-geometric, compact -- with possibly empty boundary and no spherical boundary components --, orientable Riemannian 3-manifolds having torsionfree fundamental group, with bounded entropy and diameter. By "local", we mean that we consider S endowed with the Gromov-Hausdorff-topology. We shall provide examples to show the necessity of the assumptions and discuss some open problems. Moreover, we shall give a proof of the finiteness of the homeomorphism types of the manifolds in S. These are joint works with A. Sambusetti (Rome, Sapienza).
• Maria Cumplido Cabello Loxodromic actions of Artin-Tits groups
Artin-Tits groups act on a certain delta-hyperbolic complex, called the additional length complex". For an element of the group, acting loxodromically on this complex is a property analogous to the property of being pseudo-Anosov for elements of mapping class groups. A well-known conjecture about mapping class groups claims that "most elements" of the mapping class group of a surface are pseudo-Anosov. In fact, we can prove that a positive proportion is pseudo-Anosov.
By analogy, we conjecture that most'' elements of Artin-Tits groups act loxodromically. More precisely, in the Cayley graph of a subgroup G of an Artin-Tits group, the proportion of loxodromically acting elements in a ball of large radius should tend to one as the radius tends to infinity. We will give a condition guaranteeing that this proportion stays away from zero. This condition is satisfied e.g. for Artin-Tits groups of spherical type, their pure subgroups and some of their commutator subgroups.
• N'Guyen-Bac Dang Degrees of iterates of rational maps
In this talk, I will explain what is a rational map, how to define its k-degrees, and I will study the k-degrees of its iterates. I will explain how the study of the growth of these sequences of numbers helps in understanding the dynamics of these maps.
• Laurent Dufloux Hausdorff dimension of limit sets at the boundary of complex hyperbolic planes
Consider the standard contact structure on the 3-sphere. The associated subriemannian metric has dimension 4. The Gromov comparison problem asks about how the Hausdorff dimension with respect to this subriemannian metric is related tothe Hausdorff dimension with respect to the usual (Riemannian) metric. We will look at this problem in the case of limit sets of discrete groups of complex hyperbolic isometries.
• Mikolaj Fraczyk Mod p homology growth of locally symmetric spaces
I will talk about the growth of the dimension of mod-p homology groups of locally symmetric spaces. Let G be a higher rank Lie group and X its symmetric space and let L be a lattice in G. Results on the rank gradient by Abert, Gelander and Nikolov imply that if L is right angled then for every sequence of subgroups (L_n) of L, the dimensions of the homology groups H_1(X/L_n,Z/pZ) grow sublinearly in the volume of X/L_n. In the special case p=2, I showed that the same statement holds for any sequence of lattices L_n with volume escaping to infinity (even if they are pairwise non-commensurable).
• Weikun He Sum-product estimates and equidistribution of toral automorphisms
Bourgain's sum-product theorem is a metric version of Erdős-Szemerédi sum-product theorem. It asserts that a typical set of real numbers grows fast under addition and multiplication. We will present a generalisation of Bourgain's theorem to matrix algebras and discuss how it is motivated by a ergodic problem, namely, quantitative equidistributions of orbits on the d-dimensional torus under sub-semigroups of SL(d,Z).
• Cyril Lacoste Dimension rigidity of lattices in semisimple Lie groups
We study actions of discrete groups on classifying spaces (or classifying spaces for proper actions). For instance the hyperbolic plane is a classifying space for proper actions of the group PSL(2,Z) (but not of minimal dimension). Such spaces can be used to compute the cohomology of the group, so we want them to have the lowest possible dimension. This leads us to the definitons of the (proper) geometric dimension and the (virtual) cohomological dimension. These two dimensions are not always equal, we will see it is the case for a lattice in the group of isometries G of a symmetric space of non-compact type without Euclidean factors (such a group is a semisimple Lie group but not necessarily connected). This result has an important consequence called "dimension rigidity", that is, the two dimensions are still equal for a group commensurable to a lattice of G.
• Erika Pieroni Minimal Entropy of 3-manifolds
We present the solution of the minimal entropy problem for non-geometric, closed, orientable 3-manifolds (that is, those manifolds which do not admit a com- plete metric locally isometric to one of the eight 3-dimensional model geometries). Together with the results of Besson-Courtois-Gallot for locally symmetric spaces and the work of Soma, Gromov et.al. on the simplicial volume of 3-manifolds and its relation with entropy, this gives a complete picture of the minimal entropy prob- lem for all closed, orientable 3-manifolds. Our work strongly builds on Souto's PhD work (unpublished), filling some gaps in the proof and completing the picture in the case of non-prime manifolds. In detail, we show that the minimal entropy is ad- ditive with respect to the prime decomposition and that for an irreducible manifold X it coincides with the sum of the volume entropies of all the JSJ components of hyperbolic type, each endowed with its complete, hyperbolic metric of nite volume. For the lower bound of MinEnt(X), we adapt Besson-Courtois-Gallot's barycenter method following Souto's ideas; then, we show how this lower bound is realized by producing a sequence of Riemannian metrics gk on X whose volume-entropies tend to
• Fanni M. SelleyErgodicity breaking in mean-field coupled map systems
Coupled map systems are simple models of a finite or infinite network of interacting units. The dynamics of the compound system is given by the composition of the (typically chaotic) individual dynamics and a coupling map representing the characteristics of the interaction. The coupling map usually includes a parameter s in [0,1], representing the strength of interaction. The main interest in such models lies in the emergence of bifurcations when s is varied. We first introduce our results for small finite systems. Then we initiate a new point of view which focuses on the evolution of distributions and allows to incorporate the investigation of a continuum of sites.
• Nasab Yassine Quantitative recurrence of one-dimensional dynamical systems preserving an infinite measure
We are interested in the asymptotic behaviour of the first return time of the orbits of a dynamical system into a small neighbourhood of their starting points. We study this quantity in the context of dynamical systems preserving an infinite measure. More precisely, we consider the case of Z-extensions of subshifts of finite type. We also consider a toy probabilistic model in order to enlighten the strategy of our proofs.
• Conference - Geometric Analysis at Roscoff
Oct 9, 2017 to Oct 13, 2017
Roscoff, from October 9th to October 13th
Organization board: Paul Baird, Gilles Carron, Ali Fardoun, Carl Tipler
Scientific board: Gérard Besson (CNRS, Institut Fourier), Olivier Biquard (ENS Paris), Ahmad El Soufi (Univ. Tours)
Geometric Analysis is the application and development of PDE tools and technics in Riemannian geometry, it is also a fundamental tool in mathematical physics. Recently, important conjectures has been solved: Poincaré's conjecture, Willmore's conjecture, Lawson's conjecture, Yau-Tian-Donaldson's conjecture and a lot of new tools has been introduced and developed : optimal transport, weak formulation of Ricci curvature, Geometric measure theory. This conference will be an opportunity for specialists from theses different areas to meet and exchange ideas, questions and knowledge.
• Conference - Lebesgue PHD meeting 2017
Oct 16, 2017 to Oct 18, 2017
Rennes, from October 16th to October 18th
Organization board: Grégory Boil, Valentin Doli, Caroline Robet, Jérôme Spielmann
Scientific board: Solène Bulteau, Clément Rouffort, Nasab Yassine
Depuis trois ans, le Centre Henri Lebesgue soutient les Rencontres doctorales Lebesgue, initiative des doctorants du Labex. Il s'agit de trois journées de conférences durant lesquelles la parole est donnée à des doctorants de tout horizon géographique et mathématique. L'objectif est ainsi de présenter un panel le plus large possible de la recherche mathématique actuelle telle qu'elle est vue et vécue par les doctorants, mais pas seulement... Lors de ces rencontres, trois chercheurs, appelés 'parrains' de l'évènement, sont invités à exposer et ainsi à partager leur expérience personnelle de la recherche d'aujourd'hui. Cette année, les rencontres sont parrainées par :
Jean-Marc Bardet (SAMM, Université Paris 1);
Jasmin Raissy (Institut mathématique de Toulouse, Université Paul Sabatier);
Gabriel Rivière (Laboratoire Paul Painlevé, Université de Lille 1).
Bien que principalement orientée vers les doctorants, cette conférence se veut également accessible aux étudiants de M2 désireux d’avoir un aperçu des travaux auxquels une thèse en mathématiques peut mener. Il est de plus possible pour des doctorants désireux d'exposer de déposer des propositions sur l'onglet 'Proposer un Exposé'.
• Complex dynamics and quasi-conformal geometry
Oct 23, 2017 to Oct 25, 2017
Our colleague Tan Lei passed away in April 2016. A conference will be held from 23/10/2017 to 25/10/2017 at the University of Angers to honour her memory.
### Scientific Committee
Etienne Ghys (ENS Lyon)
John Milnor (Stony Brook)
Mitsuhiro Shishikura (Kyoto).
### Organizing Committee
Mohammed El Amrani (Angers)
Michel Granger(Angers)
Jean-Jacques Loeb(Angers)
Pascale Roesch(Toulouse).
### Provisional list of speakers
Xavier Buff, Arnaud Cheritat, Nuria Fagella (to be confirmed), Cui Guizhen,Peter Haissinski, John Hamal Hubbard (to be confirmed), Carsten lunde Petersen, Kevin Pilgrim, Mary Rees, Pascale Roesh, Hans Henrik Rugh, Dylan Thurston, Mitsu Shishikura, Giulio Tiozzo. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8181755542755127, "perplexity": 2574.179785033481}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-26/segments/1498128320679.64/warc/CC-MAIN-20170626050425-20170626070425-00694.warc.gz"} |
https://academic.oup.com/annonc/article-lookup/doi/10.1093/annonc/mdm105 | ## Abstract
Background: The registry of the Oncology Departmental in Sarawak General Hospital showed that 79% of nasopharyngeal, 77% of breast and 70% of cervix cancer patients were diagnosed at an advanced stage (stages III and IV) for year 1993. Hence, a low cost Early Cancer Surveillance Program was started in 1994, with the intent of downstaging these three most common cancers in Sarawak.
Materials and methods: The program consisted of (i) training health staff in hospital and rural clinics to improve their skills in early cancer detection, (ii) raising public awareness through pamphlets, posters and sensitization by health staff.
Results: Data analysis revealed that the program achieved downstaging in two of the cancers. Breast cancer in stage III and IV was reduced from 60% (1994) to 35% (1998) (P < 0.0001) and cervical cancer in stage III and IV from 60% (1994) to 26% (1998) (P < 0.0001). No reduction was observed for nasopharyngeal cancer at 88% (1994) to 91% (1998).
### population
The statistics presented are based on hospital case series as no accurate population-based registry was available in Sarawak at that time. However, we feel that these series can give a good representation of the Sarawak cancer pattern. That is due firstly to the fact that DRO is the only cancer facility on the island and that <2% of patients can afford to go out of the state for treatment. Secondly, in Malaysian public hospitals free treatment and free travel for treatment are provided easily to those who need, ensuring that almost all cases go for treatment. During the studied period, 1993–1999, all NPC, breast, cervix, lung, colon and rectum cancer cases of Sarawak were referred to the DRO. The four private and the five public surgeons performing surgery on breast, colon and rectal cancer surgery, consistently referred their patients for adjuvant treatment, either radiotherapy or chemotherapy. Until 2000, as no gynecologic surgery was available in Sarawak, cervical cancers were also consistently referred to DRO for radiotherapy. All lung cancers were referred unless they were so advanced that no form of treatment would have any benefit. Non-Sarawak patients (mainly Indonesians) were excluded from the series. We thus estimate that the case series studied here represent at least 80% of the cancer cases of Sarawak for the studied period, the cases missed being the ones at both ends of the socioeconomic spectrum.
### statistics
Data on PAP smear programs were obtained from the Central Laboratory Services of SGH and compared with the DRO's data. Paper files data from the registry of the DRO were entered and analyzed with Excel. P values provided correspond to Fisher's exact chi-square test calculated online at: www.matforsk.no/ola/fisher.htm.
## results
### clinical downstaging
As shown in Figure 3, the percentage of breast cancer patients presenting for treatment at late stage (stage III and IV) dropped from 77% (69/90) in 1993 to 37% (42/115) in 1998 (χ2 = 17.0; P < 0.0001). Similarly, for cervical cancer, the late-stage presentation dropped from 70% (47/67) in 1993 to 27% (28/105) in 1998 (χ2 = 31.4; P < 0.0001). For NPC, the figure shows no change from 79% (84/106) in 1993 to 92% (147/160) in 1998 (nasopharyngeal = 8.9; P > 0.40). During the same period, cancers not targeted for downstaging did not display any stage variation at presentation. Between 1994 and 1998, the percentage of late stage remained stable with 93% (n = 72) to 91% (n = 96) for lung, 63% (n = 26) to 65% (n = 26) for colon and 66% (n = 18) to 68% (n = 22) for rectum.
Figure 3.
Percentage of patients presented at late stage for nasopharyngeal cancer (NPC), breast and cervix in Department of Radiotherapy and Oncology (DRO), Sarawak General Hospital (SGH) (1991–1999).
Figure 3.
Percentage of patients presented at late stage for nasopharyngeal cancer (NPC), breast and cervix in Department of Radiotherapy and Oncology (DRO), Sarawak General Hospital (SGH) (1991–1999).
We feel that raised public awareness was more efficient than health staff training to achieve the breast and cervix results, all the more so since health staff were rotated or transferred rather rapidly and we were not able to provide multiple training in some of the sites for the period 1994–1998.
### inefficiency of the PAP smear program
The DRO's medical record review for 1993–1999 showed that most of the cervix cancer cases consulted because of symptoms (postcoital bleeding, foul smelling discharge per vagina) questioning the efficiency of the screening program implemented since 1963. This extensive review of all cervix cancer medical records showed that only 5% of the cases got a PAP smear at asymptomatic stage showing that the screening program did not reach its target.
## discussion
### validity of results
Although the statistics carried out for this analysis were based on a case series, we feel that the bias present in this series may not be sufficient to invalidate the conclusions. The Sarawak patients not seen at the DRO during the studied period would be either wealthy people (who may go for treatment abroad) or people from very remote areas who were too sick to travel at the time they were referred. Only the behavior of this last group may have been altered by the program. By decreasing late-stage presentation, the program may have decreased the number of people too sick to travel, and thus increase the absolute number of cases seen at DRO. This effect may explain the increasing number of NPC cases observed between 1995 and 1998. Such an increase in absolute case number cannot create a false positive result (i.e. spurious increased proportion of early-stage presentation).
To assess the efficiency of the program it would have been adequate to compare stage at presentation in patients from districts where the training had been done and patients from districts where the training had not been done yet. Unfortunately, such comparison was not possible because geographical origins of patients were uncertain (a large proportion of patients do not give their own address but the one of the nearest family member). In order to check if the trends observed for NPC, breast and cervix were not due to increasing global health awareness, comparisons were made with other frequent cancers for which no program had been instituted, and no changes were observed.
Our result shows that clinical approach to downstaging was achievable for cervix and breast cancer but was not successful for NPC. Increased public awareness about the signs and symptoms incorporated with easier referral to doctors helped to achieve these results. As symptoms of NPC mimic certain benign conditions, there is a need for innovative methods for early detection of this cancer and presently a novel approach is being tested in an area in Sarawak which has a high risk population and the preliminary results are encouraging.
## conclusion
Early cancer surveillance programs including education of public and heath staff can achieve clinical downstaging. The successful downstaging observed here for breast and cervix cancers is a crucial finding that is relevant to developing countries where simple and inexpensive methods could be integrated into existing health care programs. The resultant downstaging should lead to a reduction in mortality for these cancers. Educating women empowers them to self-care and gives them the opportunity to seek treatment earlier. In countries with limited financial and manpower resources, downstaging of cancers is a cost-effective way of tackling the problem of cancer burden.
The authors would like to thank the State Health Department for their assistance in funding the program.
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) | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5054318904876709, "perplexity": 4623.059455397978}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-09/segments/1487501171670.52/warc/CC-MAIN-20170219104611-00505-ip-10-171-10-108.ec2.internal.warc.gz"} |
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## CMU Summer School Recap, Part 3 (Hartline and Daskalakis)
This is the third post in a series recapping the talks at the CMU summer school on algorithmic economics (here and here are the first two). See the summer school site for abstracts, slides, and (eventually) videos.
Jason Hartline
Jason Hartline from Northwestern gave two lectures on auction design. The first lecture covered the basics of Baeysian optimal auction design (Chapters 2 and 3 of Jason’s book), the second an overview of approximation in auction design (Chapters 1, 5, and 7).
We begin with single-item auctions. By “Bayesian” we mean that the bidders have private valuations for the good that are drawn independently from (possibly different) known distributions. As a bidder, you know your own valuation but only the distributions over the other valuations. For example, suppose there are two bidders, with valuations drawn i.i.d. from the uniform distribution on [0,1]. In the second-price auction, bidding truthfully is a dominant strategy; assuming bidders do this, the expected seller revenue is the expected smaller bid, namely 1/3. What happens in a first-price auction? Bidders do not have dominant strategies, and we expect all of them to maximize their expected utility with respect to what they know — formally, to be at Bayes-Nash equilibrium. In our example, suppose that each player always bids half their valuation. A simple calculation shows that this is a Bayes-Nash equilibrium: from the perspective of a bidder with valuation v, the best response against the other bid (which is uniform in [0,1/2]) is v/2. The expected revenue at this Bayes-Nash equilibrium is the expected value of the high bid — a.k.a. 1/3, the same as in the second-price auction!
Could this “revenue equivalence” hold more generally? If so, how would we prove it? The answers are yes, and using a fundamental characterization of Bayes-Nash equilibria. In the two-bidder first-price auction, suppose your valuation is v. Then the probability that you win (over the possible competing bids) in this Bayes-Nash equilibrium is also v. In auction theory jargon, your interim allocation rule — the probability that you win, as a function of your valuation — is x(v) = v. The characterization identifies which interim allocation rules arise in Bayes-Nash equilibrium, and what the corresponding expected payments must be. First, if the interim allocation rules are nondecreasing, then there are unique interim payment rules such that these expected allocations and payments arise in Bayes-Nash equilibria (namely, $p(v) = v \cdot x(v) - \int_0^v x(z)dz$ — try it for the second-price auction!). Second, if the interim allocation rules are not monotone, then they do not correspond to any Bayes-Nash equilibrium.
Jason wrapped up his first lecture with several applications of this characterization and with a quick proof sketch. The characterization immediately implies “Revenue Equivalence”: if two (auction, equilibrium) pairs produce the same interim allocation rules (as with second-price and first-price auctions with i.i.d. bidder valuations), then they necessarily generate the same expected payments. The characterization is also useful when solving for and proving the uniqueness of Bayes-Nash equilibria (e.g., of first-price and all-pay auctions).
Jason started his second lecture with one of those simple and cool math results that everybody should know, the “prophet inequality”. N prizes arrive online. Each prize has a random value, drawn from a known distribution. Different prizes’ distributions are independent but can be different. At each time step you learn the exact value of the current prize, and you can either take it (ending the game) or move on to the next prize. The goal is to identify a stopping rule with large expected value [1]. One can derive an optimal stopping rule using backward induction. There is also a good “threshold strategy”, meaning that you pick the first prize with value exceeding a fixed threshold. A short but sweet proof shows that, if you set this threshold so that the probability of eventually picking a prize is exactly 50%, then your expected reward is at least half of the expected value of the best prize (a strong benchmark!).
Jason argued that the 2-approximate threshold strategy, while suboptimal, is more interesting than the optimal stopping rule. Some of the reasons: it is simple and easy to implement and interpret; it is robust, meaning that it doesn’t change much under perturbations of the distributions; and it is easily adapted to solve variations of the original problem. Note this “simple is better than optimal” perspective also showed up in Eva’s talk. Jason compared this style of theoretical work in auction design to Picasso’s bulls — one wants just the right level of abstraction to isolate the essential features of good auction formats.
Jason concluded with two applications of approximation in auction design. The first was to revenue maximization in multi-parameter settings, for example when there are multiple goods and each bidder has a different valuation for each. The structure of the optimal auction is poorly understood in such problems (though see Costis’s lecture, below). Assume that each bidder is unit-demand (i.e., wants only one good). One class of simple auctions is sequential posted-price mechanisms: bidders are considered one-by-one, with a bidder offered a price for each remaining good, and the bidder picks its favorite (maximizing value minus price). The results here show that these simple mechanisms can achieve a good constant-factor approximation of the optimal revenue [2]. Interpretations: unit-demand preferences behave similarly to single-parameter preferences and, in such settings, competition between bidders is not essential for near-optimal revenue.
The second application was to prior-independent auctions. These are auctions with robust performance guarantees, in that they are simultaneously near-optimal for a wide range of valuation distributions. A precursor to prior-independent auctions is a beautiful 1996 result of Bulow and Klemperer which states that, for a single-item auction with bidder valuations drawn i.i.d. from some distribution F, the revenue of the second-price auction with n+1 bidders is at least that of an optimal auction (for F) with n bidders. Thus, extra competition is more valuable than information about the underlying valuation distribution. A geometric proof of this result suggests how to design prior-independent auctions in a range of settings, essentially using a guinea pig bidder to supply a single sample from the underlying distribution, which is all that is needed for near-optimal revenue.
Costis’s second lecture was about his recent work in multi-parameter mechanism design (see here and here). For concreteness, we’ll again think about maximizing the seller’s revenue when selling several different goods, where each agent has a private valuation for each but is unit-demand (i.e., only wants one good).
Abstractly, we can think of a (direct-revelation) mechanism as a function from (truthfully reported) valuations to allocations (who gets what) and payments (who pays what), subject to incentive-compatibility constraints (truthful reporting always maximizes expected agent utility, and never yields negative expected utility). In principle, the revenue-maximizing auction can be computed as the solution to a massive linear program, where there are allocation and payment variables for every bidder, good, and (alarmingly) valuation profile. By itself, this observation is neither illuminating nor computationally useful. The research program here is to show that smaller linear programs suffice, and that optimal solutions of these linear programs have informative interpretations.
The key idea is to use a much smaller set of decision variables, as follows. Analogous to the characterization in Jason’s first lecture, an interim allocation rule induced by a mechanism specifies, for each bidder i, valuation vector v (over goods) of i, and good j, the probability that j is allocated to i when its valuation vector is v (where the randomness is over the valuations of the other bidders, and possibly also over coin flips made by the mechanism). Interim payment rules are defined in the same way. We’ll consider a linear program with only these interim values as decision variables — assuming each player’s space of valuations is given explicitly, there are only polynomially many of these. The incentive-compatibility constraints and the objective function (expected sum of payments) can be expressed directly with these variables. The catch is feasibility — after solving this linear program, can we reverse engineer a bona fide mechanism that induces the computed interim allocation rules? The answer is, not necessarily. Thus, we need to add additional constraints to the linear program to enforce the feasibility of the interim allocation rules. These constraints can be explicitly described for single-item auctions (see Rakesh’s talk in the next post), but in general they need to be generated on the fly, using a separation oracle within the ellipsoid method.
In an exciting twist to the plot, the required separation oracle turns out to be precisely the corresponding welfare maximization problem (given some valuations, allocate goods to maximize the sum of valuations). For example, with unit-demand bidders this is simply a maximum-weight matching computation. The first consequence is computational: if welfare-maximization is tractable (or more generally, tractable to approximate to within some factor), then so is revenue-maximization. The second consequence is that revenue-maximizing auctions have a conceptually simple format. To explain it, here’s what’s long been known (since Myerson (1981)) for single-parameter problems: to maximize revenue, just transform the reported valuations into “virtual valuations” and then maximize the corresponding (virtual) welfare. This transformation has a simple closed form [3]. The only new complications in the multi-parameter problems discussed here are that one must use a distribution over virtual valuation transformations, and that these transformations are given by a linear program, not an expicit formula.
1. Amusingly, Jason and I had watched this exact scenario play out two days earlier (with N=2), during the “Mystery Box” contest at a Pirates game.
2. The main steps are: upper-bound the (poorly understood) optimal revenue using that of a (well-understood) single-parameter environment by viewing each agent-good pair as a single-parameter agent (roughly, optimal revenue should only go up from the increased competition); use prophet inequality-style arguments to prove approximation guarantees for sequential posted-price mechanisms in the single-parameter relaxation; and extend these mechanisms to the original multi-parameter problem in a natural way.
3. A valuation v gets mapped to the virtual valuation $v - (1-F(v))/f(v)$, where F and f are the distribution and density functions.
## CMU Summer School Recap, Part 2 (Blum and Daskalakis)
This is the second post in a series recapping the talks at the CMU summer school on algorithmic economics (here is the first). See the summer school site for abstracts, slides, and (eventually) videos.
Avrim Blum
Next I’ll talk about the two lectures by Avrim Blum, a CMU local, about the many connections between online learning and game theory. Avrim began with a masterful development of Littlestone and Warmuth’s randomized weighted majority algorithm [1]. This is an algorithm for making decisions online (e.g., which route to take to work each day) that provides a “no-regret” guarantee: your time-averaged performance (e.g., average travel time) approaches that of the best fixed option in hindsight.
Suppose there are N so-called experts (e.g., newsletters on investing) who each give advice about a binary action (e.g., whether to buy or sell stocks tomorrow). Your job is to choose one of the two actions based on this expert advice. You incur cost 1 if you choose incorrectly, 0 otherwise. To develop some intuition, first make the unrealistic assumption that some expert always predicts correctly — how long before you can identify it? The trick is to always take the action recommended by the majority of the experts who have made no mistakes thus far. Then, every time you make a mistake, you eliminate at least half of the remaining experts from future consideration. Thus, you identify the omniscient expert after at most log N mistakes.
The majority trick seems like a good idea. How can we extend it to the case of no omniscient expert? One idea is to re-start the above algorithm as soon as every expert has made at least one mistake — then the number of mistakes that we make is at most log N times that of the best expert. To do better, we should be more mindful of how experts performed in the past. A simple but great idea is to associate a weight (read: credibility) with each expert, intitially 1, and multiply this weight by $(1-\epsilon)$ every time the expert makes a mistake (where $\epsilon$ is a parameter to be tuned later). In the randomized weighted majority algorithm, at every time step you choose an action with probability proportional to the sum of the current weights of the experts that advocate that action.
The analysis of the algorithm is jaw-droppingly slick. At each time step: if the probability of a mistake by the algorithm is p, then the expected value of the experts’ total weight drops by a $(1-\epsilon p)$ factor. On the other hand, if there is an expert that makes merely m mistakes, then its weight of $(1-\epsilon)^m$ single-handedly provides a lower bound on the experts’ total weight. Using the total weight of the experts as an intermediary, we’ve related the two quantites we care about — the algorithm’s cost and the quality of the best expert. Rewriting (taking logs and using a deft Taylor expansion) shows that the expected number of mistakes made by the algorithm is at most $(1+\epsilon)m + \epsilon^{-1} \log N$. Choosing $\epsilon$ to balance the two terms gives the desired no-regret guarantee.
The algorithm and analysis are flexible and permit several extensions. For example, to handle general bounded costs (in [0,1], say), just use the weight multiplier $(1-\epsilon c_i)$ when following the ith expert leads to a cost of $c_i$. An analogous algorithm and analysis handles bounded rewards instead of bounded costs. A more impressive extension is to the “bandit setting”, meaning the only feedback you get is the reward of the chosen strategy (e.g., you only learn the travel time of the route that you chose, not those of unchosen routes). Here Avrim covered the elegant reduction of Auer, Cesa-Bianchi, Freund, and Schapire from the bandit setting to the full-feedback setting. To use a no-regret algorithm as a black box, one must fabricate a reward for every action (the input that the black box expects) from the reward of the action you took (which is all you learn). The first trick is to assign zero reward to all unchosen actions. The second trick is to make sure the expected reward vector is unbiased by dividing the reward of the chosen action by the probability of taking it — note this can increase rewards significantly. The third trick is to control the maximum fabricated reward size by mixing in a little bit of the uniform distribution when choosing actions. The bottom line is that there are no-regret algorithms for the bandit setting, as well; the only catch is that the additive loss blows up from logarithmic in N to polynomial in N.
Having made all of us experts in online learning, Avrim moved on to applications in game theory. Here’s an amazing one: the existence of a no-regret algorithm, like randomized weighted majority, directly implies von Neumann’s Minimax theorem! Contrast this with the original proof (via a fixed-point theorem) or later proofs that explicitly use linear programming duality. Recall the Minimax theorem says that, under optimal randomized play in a zero-sum two-player game (e.g., randomizing uniformly in rock-paper-scissors), it doesn’t matter if you announce your strategy before or after that of the other player — you get the same expected payoff either way. One inequality is easy — going last can only help you. The reverse inequality can be proved by letting the row and column players play the game repeatedly, each choosing a strategy at each time step using some no-regret algorithm (where strategies correspond to experts, the game payoffs to rewards). The empirical distributions of the row and column players’ chosen strategies approach a minimax pair (equivalently, a Nash equilibrum): essentially, competing with the best expert in hindsight translates to each player doing as well as a best response to the other player’s empirical distribution (i.e., as well as choosing its strategy after that of the other player).
In non-zero sum games, simultaneous regret-minimization does not generally yield a Nash equilibrium (do you see why?), but the empirical distribution of joint play approaches the set of “coarse correlated equilibria” (see also Eva’s talk), a relaxation of correlated equilibria. There are also simple online algorithms that guarantee convergence of joint play to the smaller set of correlated equilibria — one uses an appropriately more stringent regret notion (swap regret) and constructs online algorithms that have vanishing swap regret (e.g., via a black-box reduction to standard regret-minizmization).
Avrim wrapped up by surveying some of his recent work in algorithmic game theory, including item pricing (see here for a cute vertex pricing problem in graphs and here for general results that follow from “random power of 2” pricing schemes) and ways of guiding game dynamics to good Nash equilibria (see here for positive results for fair cost-sharing in neworks).
Costis gave two lectures on different topics. Here I’ll discuss his lecture on the complexity of equilibria; a future post will discuss his recent work on auctions [2].
Recall from Avrim’s talk the history of the minimax theorem for two-player zero-sum games. von Neumann first proved it using Brouwer’s fixed-point theorem, but later proofs via linear programming duality lead to polynomial-time algorithms for computing a Nash equilibrium in such games. The known proofs of Nash’s theorem — stating that every finite nonncooperative game has at least one (mixed-strategy) Nash equilibrium — rely on fixed-point theorems. Should we be looking for a new proof of Nash’s theorem, one that results in an efficient algorithm? If not — if computing Nash equilibria is no easier than computing Brouwer fixed points — how would we prove it?
Costis began with a discussion of Brouwer’s fixed-point theorem, which states that every continuous function on a convex compact set has at least one fixed point. He outlined the proof for simplicies, which follows from Sperner’s lemma (see also Ariel’s recent post on the whining philosophers problem). This proof reduces approximate fixed-point computation to a certain type of path-following in an exponential-sized graph. In 1990, Papadimitriou defined the complexity class PPAD, essentially as all problems solvable via such a path-following algorithm. Suitable fixed-point computation problems are PPAD-complete — as hard as every problem in PPAD. Computing a Nash equilibrium is a PPAD problem. A tour de force reduction from 2005 (see here and here) proves that computing a Nash equilibrium is PPAD-complete, even in two-player non-zero-sum games. In this sense, fixed-point theorems are fundamental to Nash’s existence result, not an artifact of his proof.
What does this computational intractability mean? Paraphrasing Scarf, it suggests that Nash equilibria cannot always be used for the evaluation of economic activity (since you can’t efficiently solve for your model’s predictions). For similar reasons, Costis argued that the Nash equilibrium concept fails as a universal prediction of human behavior.
So what now? An important research direction is to identify conditions on a game that guarantee tractable equilibrium computation. Costis finished on a positve note with his tractability results for a multi-player generalization of zero-sum games [3]. The model is the following. There is an undirected network. Each node is a player. Each edge is annotated with payoffs for a two-player game, played between its endpoints. Each node picks a single strategy, and its total payoff is the sum of the payoffs from the games in which it participates (one per incident edge). The sum of the players’ total payoffs is assumed to be zero in every strategy profile. (A special case is when every edge’s game is itself zero-sum.) Amazingly, this global zero-sum condition is enough to recover equilibrium tractability: a Nash equilibrium can be computed in polynomial time, the set of equilibria is convex, and play by no-regret learning algorithms converges to the set of equilibria.
1. I fully plan to steal Avrim’s exposition for my own graduate classes.
2. Costis looked surprised when I suggested that almost none of the summer school students would have seen him talk about the complexity of equilibria before — he gave zillions of talks on the topic during 2007–2009, but this is already a new generation of PhD students!
3. Three-player zero-sum games are as general as two-player non-zero-sum games (proof: add a dummy player), so Nash equilibrium computation is PPAD-hard. Recovering tractability thus requires additional restrictions on the game.
## CMU Summer School Recap, Part 1 (Yariv and Tardos)
Earlier this month, my co-blogger Ariel and I ran a summer school on algorithmic economics [1]. In my highly biased opinion, it was a lot of fun and a big success. For those of you who couldn’t make it, videos will be posted on the summer school site in the near future. The abstracts there should give you a quick idea for the topics covered by the nine speakers. In a series of posts, I’ll discuss the talk content in a bit more detail. I hope that some of the students who participated in the school discuss their own experiences in the comments. Having now met all of them, I can confidently say that the future of algorithmic game theory/economics is in good hands!
Leeat Yariv
First up was Leeat Yariv from CalTech [2]. She talked about several aspects of modeling and reasoning about social networks. As motivation, she pointed out how interesting phenomena can be explained using non-obvious properties of networks. For example, how did the Medici family grow so powerful, when other families had greater wealth and more seats in the state legislature? Looking at the network of 15th century Florentine marriages provides an explanation — the Medici family was the most central (in a precise sense), enjoying many strategic connections through marriages, and capitalized on this to create a dynasty.
Two major themes in Leeat’s lectures were diffusion and network formation. I’m more familiar with research in computer science on these two topics, and it was cool to hear an economist’s take on them. We first considered diffusion (like the spread of viruses, the adoption of a new technology, the transmission of information, etc.) without an explicit network. This is an old topic — for example, in 1962 Everett Rogers compiled 508 diffusion studies in his book Diffusion of Innovation. Two notable patterns in these studies were “S-shaped adoption” (meaning things are adopted slowly, then very rapidly, and then slowly again) and a correlation between the likelihood of adoption by an individual and the “connectedness” of the individual. The S-curve is nicely explained by Bass’s diffusion model.
Leeat then moved on to her work with Jackson on diffusion in networks. The model is that each node of a network has two strategies, to engage or not. The cost of engaging is some constant. The benefit of engaging is given by a function of a node’s degree and the fraction of its neighbors that are engaged — for example, it could be proportional to the number of engaged neighbors. Rather than keeping track of strategy profile details, a mean field model is used — if x is the overall fraction of engaged nodes, then for the analysis we’ll assume that x is the fraction of engaged neighbors in every node’s neighborhood. Generically, symmetric equilibria correspond to a discrete set of values of x, which alternate between “tipping points” (where after a slight perturbation in x, myopic dynamics lead elsewhere) and “stable equilibria” (where myopic dynamics return to the equilibrium). An interesting problem is to understand ways of modifying preferences or the network structure to increase the amount of engagement. Increasing the degree distribution (in the sense of first-order dominance) or its variance (in the sense of mean-preserving spreads) accomplish this, in that the values of tipping points and stable equilibria decrease and increase, respectively. Increasing a node’s value for its neighbors engagement (via advertising, rebates, etc.) also increases engagement. Simple properties of the degree distribution suggest how to optimally use such increases.
Eva Tardos
The next speaker was Eva Tardos, from Cornell. The overarching theme of Eva’s lectures was to understand when simple auction formats perform well. That is, if we take design simplicity as a constraint, how close to an optimal solution can we get? For example, if we sell a bunch of different goods using only single-item auctions (second- or first-price, simultaneously or sequentially), can we approach the (optimal) welfare achieved by the (complex) VCG mechanism?
Eva spent most of her first lecture thoroughly analyzing a concrete example, which introduced several analysis motifs. The example is a special case of a very neat paper by Christodoulou, Kovacs, and Schapira. There are several goods (think potential PhD advisors). Bidders can have different valuations for different goods but only want one good (i.e., the valuation for a bundle is the maximum of the valuations for the goods in the bundle). Suppose the goods are sold using simultaneous second-price auctions — each bidder submits one bid per good, and each good is allocated separately using a Vickrey auction. How good are the Nash equilibria in the corresponding game?
As a warm up, consider pure Nash equilibria of the full-information version of the game. Here, one starts with a pure Nash equilibrium (that also satisfies a necessary “no overbidding” property), and considers a hypothetical deviation by a player for the item it receives in a welfare-maximizing allocation. Summing over all players and charging lost welfare appropriately back to the equilibrium welfare shows that the welfare of every pure Nash equilibrium is at least 50% of the maximum possible. Next, Eva showed how the structure of this analysis, which only uses the fact that each player has no regret with respect to a single and simple alternative strategy, implies that the 50% bound holds more generally for all “no regret” outcomes. (This encompasses all mixed-strategy Nash and correlated equilibria, plus more; see also Avrim’s lectures for more details.) Still more generally, Eva considered the incomplete information case, which is usually the natural one for auction settings. Here, we assumed that each bidder has a common valuation for all goods that it is interested in (and valuation 0 for the rest). There is a different analysis trick in this case, which is to use that each bidder in a Bayes-Nash equilibrium has no regret for bidding half its value on all the items that it is interested in. The result is that the expected welfare of every Bayes-Nash equilibrium is at least 25% of that of the expected optimal welfare. Interestingly, this holds even if bidders’ valuations are statistically correlated. Eva wrapped up her first lecture by showing how similar ideas can be used to prove bounds on the quality of Bayes-Nash equilibria of the generalized second-price (GSP) sponsored search auction — another example of a simple (second-price) solution being used in lieu of a “complex” (VCG) one — even when advertiser quality factors are unknown (see here for details).
For her second lecture, Eva left behind simultaneous single-item auctions and moved on to the sequential case (see here and here for details). She made a compelling case that first-price auctions need to be used instead of second-price ones — the problem being that the second-price rule permits signalling and threats via high overbids, and these lead to subgame perfect equilibria with very poor welfare. Happily, constant-factor guarantees are possible for equilibria of first-price sequential auctions. The key idea in the analysis is to consider deviations of the form: follow the equilibrium strategy until you reach the auction for the good that you would be assigned in an optimal allocation, and then bid half your value for it.
1. I can’t remember why it used to bother me that junior organizers are expected to do all the work. These days, I think it’s a great tradition!
2. Caveat: I missed Leeat’s first lecture due to a thunderstorm conspiracy, and am basing my summary of it on her slides.
## Rise of the journferences
Machine learning conferences tend to be early adopters of innovations in the conference format. A recent example is the so-called Toronto system for matching papers to reviewers via ML-type techniques. It was introduced in a UAI 2011 paper, and this year was already employed by UAI 2012. NIPS 2012 had an unusual double submission policy, which allowed concurrent submission to other venues (provided that acceptance to one venue imposes withdrawal from all others). This caused a bit of mayhem when NIPS papers were concurrently submitted to UAI, which did not endorse the same avant-garde policy.
Not to be outdone by its competitors, ICML 2013 includes the following paragraph in its CFP:
This year there will be three reviewing cycles for main conference papers. This is an experimental step toward a merger of conference and journal formats — ICML may ultimately have six two-month reviewing cycles per year. Accepted papers will appear on-line shortly after acceptance and will be available for citation at that time. As of now we are still calling ICML a conference rather than a journal. A good discussion of the issues of merging conference and journal formats can be found in p40-jagadish.pdf by H. V. Jagadish.
The boldface sentence seems to implicitly imply that the essence of conference-ness lies in the uniqueness of the deadline. Is it naive to think that a conference should be called a “conference” as long as it brings people together?
I read the paper by Jagadish and did some additional research. I turns out that VLDB 2012 had a rolling deadline on the 1st of each month, i.e., 12 submission deadlines in the year preceding the conference. As far as I understand, papers are submitted to a journal-conference hybrid called Proceedings of VLDB, and as of 2011 this is the only way to present papers in the conference. Interestingly, Jagadish’s vision (circa 2008) was to ultimately replace VLDB with a journal called Journal of Data Management Research, but this journal doesn’t seem to exist. Perhaps the reason can be found in the list of possible worries in Jagadish’s paper:
JDMR is not really a journal: To the extent that JDMR is closely associated with conference presentation, and is interested in “conference-style” papers, it is a journal-conference hybrid. I personally believe it is more a journal than a conference proceedings, on account of year-round submissions and multi-round reviews. But there are those in the community who believe strongly that such a hybrid should not be called a journal. This is a dialog in progress.
Of course, this shift is part of larger trends that were discussed on this blog, as well as in many other places. Whether we want to call them journals, conferences, or journferences, personally I think VLDB and ICML are moving in the right direction. To be honest, I would support any solution that ameliorates the IJCAI (2011 deadline: Jan 25), EC (2011 deadline: Feb 4), and AAAI (2011 deadline: Feb 8) deadline frenzy.
Hat tip: Mugizi Rwebangira.
## Fair division and the whining philosophers problem
In 2001 I moved into an apartment in Jerusalem with two friends, Naomi and Nir. The apartment had one larger bedroom and two equally-sized, smaller bedrooms. While Naomi and I were running around viewing apartments, Nir was having the time of his life in South America. Nevertheless, when he got back, he argued that he should get the larger room (and pay the same rent) because he did not have a say in choosing the apartment. Strangely enough, this outlandish argument somehow made sense at the time. Nir’s powers of persuasion did not go to waste; today he is a philosopher.
Last week the memories came rushing back when a new CMU grad student—who was attending the summer school on algorithmic economics—asked me for advice on dividing the rent between his housemates. Fortunately, now I know a bit more about fair division than I did in 2001. Here is what I told him.
There is a wonderful 1999 paper by Francis Edward Su, which presents fair division methods through Sperner’s lemma. Suppose for simplicity that there are three housemates: call them Naomi, Nir, and Ariel, and denote them by A, B, and C. We denote the price of room $i$ by $x_i$, and assume that the prices are positive and the total rent is 1, so $x_1+x_2+x_3=1$. Our goal is to divide the rent so that each person prefers a different room.
The space S of possible partitions of the rent can be represented as a triangle (or, if you want to be formal, a 2-simplex in $\mathbb{R}^3$). Now, triangulate S, and assign ownership of each vertex to one of A, B, and C, in a way that each elementary triangle is an ABC triangle. See the figure below, which is copied from the paper.
Next, we ask the owner of each vertex to tell us which of the rooms he prefers at the prices that are represented by the vertex. In this way, we obtain a new labeling of the triangle by the labels 1, 2, and 3. If we assume that people always want a free room when one is offered to them, the labeling of the edges of the triangle is constrained (because the vertices there have a price of zero for at least one room), and in fact it looks like this:
A variant of Sperner’s lemma implies that for such a labeling, there must be an elementary 123 triangle, i.e., a “small” triangle whose vertices have different labels. But such a a triangle is nothing but three “similar” partitions of the rent in which different people choose different rooms! By choosing a sufficiently fine triangulation we can make these three vertices arbitrarily close, thereby obtaining an approximately envy-free allocation. In the limit (and under an additional mild assumption) we can obtain a completely envy-free allocation. These techniques easily generalize to the case of more than three housemates. By the way, the connection to Sperner also implies computational hardness; and in theory it’s possible to use the completely different techniques of Lipton et al. to obtain an approximately envy-free division.
Su actually went ahead and implemented his scheme as a component in his fair division calculator. It’s not much to look at, but keep in mind that it dates back to the era when Java applets were cool. One of the nicest things about the algorithm is that you just need to ask players queries of the following form: “under these prices, which room do you want?” The algorithm iteratively poses these questions to the housemates and uses the answers to refine its solution. Fair division theory has given rise to such amazingly practical and beautiful methods, and I can’t help but wonder whether a flashier fair division calculator (perhaps a smartphone app) would be used by hundreds of thousands.
(A video of Herve Moulin’s mini-course on fair division will soon be available here. For now you can check out his slides, or read a related survey that I wrote a few weeks ago for CACM.) | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 14, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7896928191184998, "perplexity": 1027.1134490377206}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-05/segments/1579251700675.78/warc/CC-MAIN-20200127112805-20200127142805-00340.warc.gz"} |
https://www.eurotrib.com/comments/2008/1/1/11415/37691/90 | Welcome to European Tribune. It's gone a bit quiet around here these days, but it's still going.
Worse: in my view, by creating simplistic categories while the reality of human psychology is much more complex and contrasting them with one another to create dichotomies while these qualities ("attitudes", "functions" and "lifestyles") coexist and interact, this test favours preconceptions and even, sometimes, prejudices. For example, contrasting thinking and feeling is in contradiction with all the knowledge developed by the modern cognitive sciences. "Dieu se rit des hommes qui se plaignent des conséquences alors qu'ils en chérissent les causes" Jacques-Bénigne Bossuet
M-B doesn't give you discrete categories but a gradation. For instance, I am: Introverted (I) 64% Extraverted (E) 36% Intuitive (N) 68% Sensing (S) 32% Thinking (T) 90% Feeling (F) 10% Perceiving (P) 55% Judging (J) 45% We have met the enemy, and he is us — Pogo
M-B doesn't give you discrete categories but a gradationMaybe, but the result is not a grade on a scale but a dichotomic categorisation: you're either Thinking or Feeling. The statistical validity of the MBTI as a psychometric instrument has also been subject to criticism, in particular, the dichotomous scoring of dimensions. For example, it was expected that scores would show a bimodal distribution with peaks near the ends of the scales. However, scores on the individual subscales are actually distributed in a centrally peaked manner similar to a normal distribution. A cut-off exists at the centre of the subscale such that a score on one side is classified as one type, and a score on the other side as the opposite type. This fails to support the concept of type--the norm is for people to lie near the middle of the subscale. BTW, I had a look at the test and I find many items highly questionable from a methodological point of view. For example, these questions: "You tend to be unbiased even if this might endanger your good relations with people" "Strict observance of the established rules is likely to prevent a good outcome" "It is in your nature to assume responsibility" "You easily see the general principle behind specific occurrences" I find several problems: These questions use polysemous words without clarifying their definition Many of them are value-charged A great number could/should be answered by something else than YES or NO The whole test presupposes you have an objective vision of yourself... "Dieu se rit des hommes qui se plaignent des conséquences alors qu'ils en chérissent les causes" Jacques-Bénigne Bossuet
I agree entirely. I've been subjected to M-B and similar tests on a number of occasions (mainly when I was briefly studying for a master's degree in education, an effort mercifully abandoned before it did too much damage) and have never found any of them terribly illustrative or insightful. I don't think they measure what they purport to measure fairly well, and I personally don't easily fit into those boxes -- so at different times have gotten different results, especially on the T/F scale, but on the other ones as well. Why on Earth would I want to think of myself as a certain "type" if I'm barely two percentage points away from being a different "type," especially when I haven't the faintest idea how to answer a good chunk of the questions because they're bizarrely worded? The traditional approach to some tests (not necessarily M-B) even tends to view people who are "undifferentiated" as somehow dangerous, rather than as, uh, well-rounded.
I'm INFJ - but an astounding moderate one at that (Introverted 33, Intuitive 6, Feeling 38, Judging 1). Apparently this makes me a Counselor type. Which I would find flattering.The Counselor Idealists are abstract in thought and speech, cooperative in reaching their goals, and enterprising and attentive in their interpersonal roles. Counselors focus on human potentials, think in terms of ethical values, and come easily to decisions. The small number of this type (little more than 2 percent) is regrettable, since Counselors have an unusually strong desire to contribute to the welfare of others and genuinely enjoy helping their companions. Although Counsleors tend to be private, sensitive people, and are not generally visible leaders, they nevertheless work quite intensely with those close to them, quietly exerting their influence behind the scenes with their families, friends, and colleagues. This type has great depth of personality; they are themselves complicated, and can understand and deal with complex issues and people. BTW, if there will be a B-M compass, I think everyone should do the same test. I just googled my way to one.
I worked my way through the other personality types and I too was reminded of *cough * astrology...
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by gmoke - Jan 20
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by Oui - Jan 15 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.34273141622543335, "perplexity": 4569.120112653319}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2023-06/segments/1674764500837.65/warc/CC-MAIN-20230208155417-20230208185417-00622.warc.gz"} |
http://mathhelpforum.com/algebra/174131-pool-problem-print.html | # The Pool Problem
• March 10th 2011, 09:20 AM
Caity
The Pool Problem
Jim can fill a pool carrying buckets of water in 30 minutes. Sue can do the same job in 45 minutes. Tony can do the same job in 1 1/2 hours. How quickly can all three fill the pool together? I know the answer is 15 minutes... again I need to find a way to explain it...
• March 10th 2011, 09:33 AM
masters
Quote:
Originally Posted by Caity
Jim can fill a pool carrying buckets of water in 30 minutes. Sue can do the same job in 45 minutes. Tony can do the same job in 1 1/2 hours. How quickly can all three fill the pool together? I know the answer is 15 minutes... again I need to find a way to explain it...
Hi Caity,
Ah...the good old work problem.
Jim can fill the pool in 30 minutes. So, he fills 1/30 of the pool in 1 minute.
Sue can fill the pool in 45 minutes. So, she fills 1/45 of the pool in 1 minute.
Tony can fill the pool in 90 minutes. So, he fills 1/90 of the pool in 1 minute.
$\frac{1}{30}+\frac{1}{45}+\frac{1}{90}=\frac{1}{t}$
Now, solve for t.
If you multiply everything by t, the equation will look this way:
$\frac{1}{30}t+\frac{1}{45}t+\frac{1}{90}t=1$
You can find similar "work" problems and a pretty good explanation here: "Work" Word Problems
Also, here is a related thread in this forum: http://www.mathhelpforum.com/math-he...ng-172924.html | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 2, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.38988590240478516, "perplexity": 766.8700132530186}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-22/segments/1432207928076.40/warc/CC-MAIN-20150521113208-00317-ip-10-180-206-219.ec2.internal.warc.gz"} |
http://tex.stackexchange.com/questions/13781/multiple-copies-of-short-page-on-one-sheet-of-paper?answertab=oldest | # Multiple copies of short page on one sheet of paper
Suppose you have a short document (including a fancy header) which occupies only a small part of a DIN A4 page, like in this example:
\documentclass[a4paper, 12pt]{article}
\usepackage[top=2cm,hmargin=2.2cm]{geometry}
\usepackage{fancyhdr}
\pagestyle{fancy}
\fancyhf{}
\fancyfoot[C]{}
\begin{document}
short text short text short text short text short
text short text short text short text short text short
text short text short text short text short text short
text short text short text short text short text short
text short text short text short text short text end of the text.
\end{document}
Suppose I want to print this text 50 times. To save paper I would print it and use a photocopier to copy this text incl. fancy header several times to one sheet of paper.
Now my question is, if there is a simple LaTeX way to do this, i.e. in the above example, have as many copies of all text from fancy header to "end of the text" automatically on a DIN A4 sheet as you can fit on it?
-
I do not know an fully automatically way, but it is possible to do it manually with minimal adjustments.
# First way:
Reduce the height of the page to the minimal height by replacing a4paper with pagewidth=21cm,pageheight=4cm (here 21cm is the A4 width and 4cm depends on the text content and margin requirements).
\usepackage[top=2cm,hmargin=2.2cm,paperwidth=21cm,paperheight=4cm]{geometry}
Then create a second small LaTeX document which includes the PDF of the first using the pdfpages pages and places it multiple times on one page:
\documentclass[a4paper]{article}
\usepackage{pdfpages}
\begin{document}
\includepdf[page={1,1,1,1,1,1,1},nup=1x7]{mainfile}
\end{document}
This places the first document (called mainfile.tex/.pdf here) seven times on page. Adjust both the number of 1, and the number of nup=1x to the real number which fit on one page.
# Second way:
You could create the headers using normal text instead so it can be repeated over the page. A tabular would be adequate here. Putting the main text into one multi-column cell also prevents page breaks inside the text. The the text could be repeated using a loop. Adjust the \vspaces and the repeat numbers to fit your requirements.
\documentclass[a4paper, 12pt]{article}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[pdftex]{graphicx}
\usepackage[top=2cm,hmargin=2.2cm]{geometry}
\pagestyle{empty}
\begin{document}
\newcount\num
\loop\ifnum\num<7
\par\noindent
\begin{tabular}{@{}l@{}r@{}}
\hline\noalign{\vspace{.5cm}}
\multicolumn{2}{@{}p{\linewidth}@{}}{%
\hspace*{\parindent}% if par indent is required
short text short text short text short text short
text short text short text short text short text short
text short text short text short text short text short
text short text short text short text short text short
text short text short text short text short text end of the text
}
\end{tabular}
\par\vspace{1cm}%
\repeat
\end{document}
-
The problem I am finding with this (2nd) solution is, if I put a \ in the text, I get endless stream of errors given below ... see removed non-answer – Tem Pora Nov 24 '12 at 6:56
I found another solution to be simpler, I want to have everything in one file which simplifies everythingh. With the pdfpages solution that is not possible. Simply define the text you want to repeat as a command, with \newcommand{\repeatthis}{text}, and then simply use that command multiple times. As a complete example, I show the complete file for a yahtzee scoresheet, using this technique:
% yahtzee-scoresheet in \LaTeX
\documentclass[a4,12pt,landscape,pdftex]{standalone}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{array}%%%%%Extended, modernized version of tabular
\usepackage[misc]{ifsym}%%%%%\Cube{} command
%%%%% Defining commands for yatzee names:
\newcommand{\one}{\Cube{1}}
\newcommand{\two}{\Cube{2}}
\newcommand{\three}{\Cube{3}}
\newcommand{\four}{\Cube{4}}
\newcommand{\five}{\Cube{5}}
\newcommand{\six}{\Cube{6}}
\newcommand{\onepair}{\Cube{1}\Cube{1}}
\newcommand{\twopair}{\Cube{2}\Cube{2}~\Cube{3}\Cube{3}}
\newcommand{\thrice}{\Cube{3}\Cube{3}\Cube{3}}
\newcommand{\fourequal}{\Cube{4}\Cube{4}\Cube{4}\Cube{4}}
\newcommand{\house}{\onepair{}~\thrice}
\newcommand{\straight}{\Cube{1}\Cube{2}\Cube{3}\Cube{4}\Cube{5}}
\newcommand{\sstraight}{\Cube{2}\Cube{3}\Cube{4}\Cube{5}\Cube{6}}
\newcommand{\yatzee}{\Cube{6}\Cube{6}\Cube{6}\Cube{6}\Cube{6}}
\newcommand{\chance}{\textbf{sjanse}}
\newcommand{\bonus}{\textbf{bonus}}
\newcommand{\total}{\textbf{sum}}
\dimen0=0.6cm{} %%%%% To use within the tabular environment
\newcommand{\onesheet}{%%%%% The complete score sheet:
\begin{tabular}[t]{||l||p{\dimen0}|p{\dimen0}|p{\dimen0}|p{\dimen0}|p{\dimen0}|p{\dimen0}||}\hline \hline
& & & & & & \\ \hline
\one & & & & & & \\ \hline
\two & & & & & & \\ \hline
\three & & & & & & \\ \hline
\four & & & & & & \\ \hline
\five & & & & & & \\ \hline
\six & & & & & & \\ \hline \hline
\total & & & & & & \\ \hline
\bonus & & & & & & \\ \hline \hline
\onepair & & & & & & \\ \hline
\twopair & & & & & & \\ \hline
\thrice & & & & & & \\ \hline
\fourequal & & & & & & \\ \hline
\house & & & & & & \\ \hline
\straight & & & & & & \\ \hline
\sstraight & & & & & & \\ \hline
\yatzee & & & & & & \\ \hline
\chance & & & & & & \\ \hline \hline
\total & & & & & & \\ \hline \hline
\end{tabular}
}
\begin{document}
\onesheet \\[15mm]
\onesheet
\end{document}
-
So how do you replicate the header/footer the way the OP requested? In that sense your approach doesn't solve the problem. – Werner Jan 12 at 20:48 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9998425245285034, "perplexity": 1342.1355819344358}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-35/segments/1440645257063.58/warc/CC-MAIN-20150827031417-00239-ip-10-171-96-226.ec2.internal.warc.gz"} |
http://www.aimspress.com/article/10.3934/mine.2021024/fulltext.html | Research article Special Issues
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Mean field games of controls: Finite difference approximations
Université de Paris and Sorbonne Université, CNRS, Laboratoire Jacques-Louis Lions, (LJLL), F-75006 Paris, France
This contribution is part of the Special Issue: Critical values in nonlinear pdes – Special Issue dedicated to Italo Capuzzo Dolcetta
Guest Editor: Fabiana Leoni
## Abstract Full Text(HTML) Figure/Table Related pages
We consider a class of mean field games in which the agents interact through both their states and controls, and we focus on situations in which a generic agent tries to adjust her speed (control) to an average speed (the average is made in a neighborhood in the state space). In such cases, the monotonicity assumptions that are frequently made in the theory of mean field games do not hold, and uniqueness cannot be expected in general. Such model lead to systems of forward-backward nonlinear nonlocal parabolic equations; the latter are supplemented with various kinds of boundary conditions, in particular Neumann-like boundary conditions stemming from reflection conditions on the underlying controled stochastic processes. The present work deals with numerical approximations of the above megntioned systems. After describing the finite difference scheme, we propose an iterative method for solving the systems of nonlinear equations that arise in the discrete setting; it combines a continuation method, Newton iterations and inner loops of a bigradient like solver. The numerical method is used for simulating two examples. We also make experiments on the behaviour of the iterative algorithm when the parameters of the model vary.
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# References
1. UMFPACK. Available from: http://www.cise.ufl.edu/research/sparse/umfpack/current/.
2. Achdou Y (2013) Finite difference methods for mean field games, In: Hamilton-Jacobi Equations: Approximations, Numerical Analysis and Applications, Heidelberg: Springer, 1-47.
3. Achdou Y, Capuzzo-Dolcetta I (2010) Mean field games: Numerical methods. SIAM J Numer Anal 48: 1136-1162.
4. Achdou Y, Lasry JM (2019) Mean field games for modeling crowd motion, In: Contributions to Partial Differential Equations and Applications, Cham: Springer, 17-42.
5. Achdou Y, Porretta A (2018) Mean field games with congestion. Ann I H Poincaré Anal non linéaire 35: 443-480,
6. Bensoussan A, Frehse J, Yam P (2013) Mean field games and mean field type control theory. New York: Springer.
7. Bonnans FJ, Hadikhanloo S, Pfeiffer L (2019) Schauder estimates for a class of potential mean field games of controls. arXiv:1902.05461.
8. Cardaliaguet P, Lehalle CA (2018) Mean field game of controls and an application to trade crowding. Math Financ Econ 12: 335-363.
9. Carmona R, Delarue F (2015) Forward-backward stochastic differential equations and controlled McKean-Vlasov dynamics. Ann Probab 43: 2647-2700.
10. Carmona R, Delarue F (2018) Probabilistic theory of mean field games with applications I, Cham: Springer.
11. Carmona R, Lacker D (2015)) A probabilistic weak formulation of mean field games and applications. Ann Appl Probab 25: 1189-1231.
12. Gomes D, Voskanyan V (2013) Extended mean field games. Izv Nats Akad Nauk Armenii Mat 48: 63-76.
13. Gomes DA, Patrizi S, Voskanyan V (2014) On the existence of classical solutions for stationary extended mean field games. Nonlinear Anal 99: 49-79.
14. Huang M, Caines PE, Malhamé RP (2007) Large-population cost-coupled LQG problems with nonuniform agents: Individual-mass behavior and decentralized $\epsilon$-Nash equilibria. IEEE T Automat Contr 52: 1560-1571.
15. Huang M, Caines PE, Malhamé RP (2006) Large population stochastic dynamic games: closed-loop McKean-Vlasov systems and the Nash certainty equivalence principle. Commun Inf Syst 6: 221-251.
16. Kobeissi Z (2019) On Classical Solutions to the Mean Field Game System of Controls. arXiv:1904.11292.
17. Lasry JM, Lions PL (2006) Jeux à champ moyen. I. Le cas stationnaire. C R Math Acad Sci Paris 343: 619-625.
18. Lasry JM, Lions PL (2006) Jeux à champ moyen. II. Horizon fini et contrôle optimal. C R Math Acad Sci Paris 343: 679-684.
19. Lasry JM, Lions PL (2007) Mean field games. JPN J Math 2: 229-260.
20. Lions PL, Théorie des jeux à champs moyen. Video lecture series at Collège de France, 2011-2019. Available from: https://www.college-de-france.fr/site/pierre-louis-lions/index.htm.
21. van der Vorst HA (1992) Bi-CGSTAB: A fast and smoothly converging variant of Bi-CG for the solution of nonsymmetric linear systems. SIAM J Sci Statist Comput 13: 631-644. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8574817180633545, "perplexity": 8457.780391075281}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-34/segments/1596439737238.53/warc/CC-MAIN-20200808021257-20200808051257-00337.warc.gz"} |
https://brilliant.org/problems/how-fast-will-this-become-popular/ | # How fast will this become popular?
Suppose the probability that this problem will become popular half an hour after posting it is $$\dfrac{13682}{16807}$$. Assume that the probability this problem will become popular at any given time within this half hour remains the same. Then, the probability that this problem will become popular 6 minutes after posting it equals $$\dfrac{a}{b}$$, where $$a, b$$ are relatively prime positive integers. Find $$a + b$$.
×
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Set Loading... | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.47226884961128235, "perplexity": 298.7404881407526}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-43/segments/1508187824325.29/warc/CC-MAIN-20171020192317-20171020212317-00209.warc.gz"} |
https://math.stackexchange.com/questions/901849/prove-equilateral-triangle | prove equilateral triangle
Recently I have encountered such a proving problem.
As shown below, given a $\triangle ABC$, $AD$ intersects $BC$ at $D$ so that $AD$ is perpendicular to $BC$, $BE$ intersects $AC$ at $E$ so that $BE$ is the angle bisector of $\angle ABC$, $CF$ intersects $AB$ at $F$ so that $CF$ is the median of $AB$, $AD$, $BE$, $CF$ intersect at a common point.
We need to prove that triangle ABC is an equilateral triangle. I have tried several approaches, but it seems useless in the end.
Any thoughts? Or is it actually not an equilateral triangle?
Start by fixing points $A$ and $B$. We also fix a third point $C^\prime$ and require that $C$ lie on the ray $\vec{BC^\prime}$. Drop a perpendicular from $A$ down to $BC^\prime$ and call the point of intersection $D$. Next construct the angle bisector of $\angle ABC^\prime$; denote the intersection of the angle bisector with the line $AD$ by $G$. Finally, construct the midpoint $F$ of $AB$, and extend a line through $F$ and $G$. The intersection of $FG$ and $BC^\prime$ determines the third vertex of the triangle, $C$.
The result is that for any angle $\angle ABC^\prime$, there is a point $C$ such that the triangle $\triangle ABC$ satisfies all of our hypotheses. And of course, if $\angle ABC^\prime$ is not necessarily $60^\circ$, then $\triangle ABC$ is not necessarily equilateral.
EDIT: The last paragraph is not entirely correct. The first sentence should read: for any $\color{red}{\text{non-obtuse}}$ angle $\angle ABC^\prime$, there is a point $C$ such that the triangle $\triangle ABC$ satisfies all of our hypotheses. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9503083229064941, "perplexity": 36.383242052319225}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-39/segments/1568514575627.91/warc/CC-MAIN-20190922180536-20190922202536-00466.warc.gz"} |
https://community.endnote.com/t/attached-pdf-issues-when-importing-ris-into-x6/292432 | # attached pdf issues when importing .ris into X6
I have been trying to export some references with attached pdfs from Mendeley desktop into Endnote X6 (win7 OS). I’ve tried exporting as endnote .xml, and then importing that file from endnote, but the pdfs are not getting copied into the pdf subfolder in the data folder. So the references have the broken attachment message: "The following file could not be opened. This may occur for a number of reasons including, but not limited to: the file is corrupt or the relative link was deleted.
File D:\References\temp pdf import.Data\PDF\Cothran, Brown, Relyea - 2013 - Proximity to agriculture is correlated with pesticide tolerance evidence for the evolution of amphibian.pdf"
I do have the “copy new file attachments into default folder” option checked in the preferences window. I have also tried exporting the references as a .ris. When I import that file the absolute links to the pdfs are maintained, but no new relative links are created. I’d like the relative links to be created so that I don’t end up with pdfs associated with one library in two different folders.
Any ideas how to make this process work better?
Thanks,
Kevin
If the links are there as absolute (mind you- I have never tried this, so if they are URLs and not attachments this won’t work) then you can ask Endnote to convert Absolute to relative and it will copy the files to the subfolder structure. This option in X7 is under references, file attachments> “convert to relative links”.
That worked (converting to relative links). I’m leaving the post open (not accepting your solution as a solution) in hopes that someone has an idea about how to get the files imported as relative links directly. But thanks for the solution!
Kevin | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.811519980430603, "perplexity": 3457.1663898684064}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-27/segments/1656103329963.19/warc/CC-MAIN-20220627073417-20220627103417-00626.warc.gz"} |
http://freakonometrics.hypotheses.org/47962 | # Simple Distributions for Mixtures?
The idea of GLMs is that given some covariates$X$$Y|X$ has a distribution in the exponential family (Gaussian, Poisson, Gamma, etc). But that does not mean that $Y$ has a similar distribution… so there is no reason to test for a Gamma model for $Y$ before running a Gamma regression, for instance. But are there cases where it might work? That the non-conditional distribution is the same (same family at least) than the conditional ones?
For instance, if $(X,Y)$ has a joint Gaussien distribution, then both marginals are Gaussian, but also $Y|X$. So, in that case, if the covariate is normally distributed, it is possible to have a Gaussian distribution also for $Y$. The econometric interpretation is that with a standard Gaussian linear model, if$X$ is normally distributed, not only the conditional distribution $Y|X$ is Gaussian but also the non-conditional distribution of $Y$.
> set.seed(1)
> n=1e3
> X=rnorm(n,10,2)
> Y=1+3*X+rnorm(n)
> plot(X,Y,xlim=c(4,20))
Indeed, here the distribution of $Y$ is also Gaussian
> library(nortest)
Anderson-Darling normality test
data: Y
A = 0.23155, p-value = 0.802
> shapiro.test(Y)
Shapiro-Wilk normality test
data: Y
W = 0.99892, p-value = 0.8293
(not only from a statistical point of view, the thoery of Gaussian random vectors confirms that the non-conditional distribution is Gaussian actually)
Here $X$ is continuous. What if we consider a finite mixture here, i.e.$X$ takes only a finite number of values? Actually, Teicher (1963) proved that it is not possible to have a non-conditional Gaussian distribution for $Y$. But in practice, would we really reject the Gaussian assumption, for $Y$? If the number of classes is to small, yes. But with a large number of classes (a sufficiently large number of mixture components), it is possible,
> pv=function(k=2){
+ n=1e4
+ X=rnorm(n,10,2)
+ Q=quantile(X,(0:k)/k)
+ Q[1]=0
+ Xc=cut(X,Q,labels=1:k)
+ XcN=tapply(X,Xc,mean)
+ Xn=XcN[as.numeric(Xc)]
+ Y=1+3*Xn+rnorm(n)
> plot(2:100,Vectorize(pv)(2:100),type="l")
> abline(h=.05,col="red")
So here, it could be possible to have also a Gaussian distribution, for $Y$. As least to accept that assumption, statistically.
In the context of a Poisson regression, it is well know that it’s not possible to have at the same time $Y|X$ that is Poisson distributed (that’s a Poisson regression) and also $Y$ that is Poisson distributed. That simply comes from the fact that
$\mathbb{E}[Y]=\mathbb{E}[\mathbb{E}[Y\vert X]]$
while
$\text{Var}[Y]=\mathbb{E}[\text{Var}[Y\vert X]]+\text{Var}[\mathbb{E}[Y\vert X]]$
and because of the conditional Poisson distribution, then
$\text{Var}[Y\vert X]=\mathbb{E}[Y\vert X]$
Thus,
$\text{Var}[Y]=\mathbb{E}[Y]+\underbrace{\text{Var}[\mathbb{E}[Y\vert X]]}_{>0}$
So $Y$ cannot be Poisson distribution. But again, it could be possible, if heterogeneity is not too large, to accept the null assumption of a Poisson distribution for $Y$.
More generally, it is very difficult to have a distribution family for $Y|X$ that is also the distribution of the non-conditional variable $Y$. In the context of a finite mixture ($X$ takes a finite number of values),Teicher (1963) proved that it was not not possible, neither for the Gaussian distribution nor the Gamma distribution. An to go further, check Monfrini (2002) (thanks Romuald for point out the reference).
Hence, as a keep saying, before running a regression model on$Y|X$ with some given family, it is never a good idea to check if the non-conditional distribution $Y$ has the same distribution. Because there is no reason, usually, to remain in the same family. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 29, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8877949714660645, "perplexity": 4756.805699780511}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-36/segments/1471982296020.34/warc/CC-MAIN-20160823195816-00106-ip-10-153-172-175.ec2.internal.warc.gz"} |
http://www.birs.ca/events/2013/5-day-workshops/13w5069/videos/watch/201307011609-Deconinck.html | ## Video From 13w5069: Water waves: computational approaches for complex problems
Monday, July 1, 2013 16:09 - 16:50
The inverse water wave problem | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9350680112838745, "perplexity": 11370.72909368329}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-40/segments/1474738662022.71/warc/CC-MAIN-20160924173742-00071-ip-10-143-35-109.ec2.internal.warc.gz"} |
https://www.wptricks.com/question/css-vertical-mega-menu-disappears-too-quickly-after-mouse-leave/ | ## css – Vertical Mega Menu disappears too quickly after mouse leave
Question
I have created a vertical menu on WordPress, but I’m having a problem because the Mega Menu is disappearing too quickly. As you can see in the image there is a gap between last category with menu shown on hover and the list must be ordered like that, so I have tried to add delay timer after mouse leave category tab so the visitor can click on the link. I still think that the best way is to add setTimer for delay after leaving cursor.
Website link where I work: https://tdb.pfm.mybluehost.me/
What I have tried:
$(function() { var timer = 0;$(“ul.dropdown > li”).hover(function()
{
if (timer) clearTimeout(timer);
$(“ul.dropdown > li”).removeClass(“hover”);$(“ul.dropdown > li ul”).css(‘visibility’, ‘hidden’);
$(this).addClass(“hover”);$(‘ul:first’,this).css(‘visibility’, ‘visible’);
}, function()
{
var link = $(this); timer = setTimeout(function(){$(link).removeClass(“hover”);
$(‘ul:first’,link).css(‘visibility’, ‘hidden’); }, 5000); });$(“ul.dropdown li ul li:has(ul)”).find(“a:first”).append(” » “);
});
I have added this but not working, so during the search on internet it seems that the problem also can be solved using only css to set delay after mouse leave.
0
2 months 2021-08-07T04:45:31-05:00 0 Answers 0 views 0 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.18359750509262085, "perplexity": 3203.42430726353}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-39/segments/1631780057796.87/warc/CC-MAIN-20210926022920-20210926052920-00103.warc.gz"} |
https://math.meta.stackexchange.com/questions/4019/shouldnt-there-be-an-easy-way-to-sketch-a-solution | # Shouldn't there be an easy way to sketch a solution?
I love the fact that this site supports $\LaTeX$, but some things are more easily explained with a free-form drawing. Many people I know have a drawing tablet, and many javascript libraries to allow such input are available freely.
And of course, making a drawing in your favorite MS Paint substitute and uploading it /works/, but I doubt anyone would like to do it that way. Integrating free-form drawing input into this website would allow many mathematicians to express their ideas more freely.
Edit: I would imagine that in the edit box, alongside the "Insert image" button, there would be an "Start sketching" button, which would either open a new window or get some space in the page itself, where with a minimal set of buttons you could make an easy sketch of your thoughts. Nothing fancy, just click to draw, no standard forms like squares or circles, no airbrush tools or layers or filters or effects, just a pen, and maybe colors.
• Probably a request that should go to the main stackexchange rather than here in math. – GEdgar Apr 21 '12 at 13:21
• @GEdgar: Actually it was established a long time ago that feature requests can come from any meta site. If you consider the needs for this then much like the $\LaTeX$ support which is a unique feature of the math site (and then a few more started using it) this might start as a unique feature as well. – Asaf Karagila Apr 21 '12 at 13:55
• I bumped this post since something similar was recently suggested in this answer. – Martin Sleziak Oct 21 '14 at 6:39
• There is also a feature request at meta.SE: Drawing/Sketching Tool for elaborating questions. – Martin Sleziak Oct 21 '14 at 6:40 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.18220417201519012, "perplexity": 1044.4942332664502}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-45/segments/1603107872746.20/warc/CC-MAIN-20201020134010-20201020164010-00543.warc.gz"} |
http://mathoverflow.net/questions/75921/what-is-the-tensor-product-for-the-eilenberg-moore-category-of-a-commutative-mona | # What is the tensor product for the Eilenberg-Moore category of a commutative monad?
In Linear logic, monads and the lambda calculus (DRAFT), Proposition 3.0.2 says that the Eilenberg-Moore category for a commutative monad has the structure of a symmetric monoidal closed category. My question is: How do you construct the tensor product for the EM-category? When I followed the reference to Kiegher's paper "Symmetric monoidal closed categories generated by commutative adjoint monads", that paper only seems to give the construction for monads of the form A ⊗ -. I don't see how to generalize the construction to arbitrary commutative monads.
-
One reference that says this explicitly is Gavin J. Seal, "Tensors, monads and actions", arxiv.org/abs/1205.0101, see beginning of section 2.2 and then theorem 2.5.5. On the nLab see here: ncatlab.org/nlab/show/… – Urs Schreiber Feb 12 '14 at 22:42
Let $T \colon C \to C$ be your monad. Being commutative, it comes with maps $\mathrm{dst} \colon T(A) \otimes T(B) \to T(A \otimes B)$. Let $\phi \colon TA \to A$ and $\psi \colon TB \to B$ be algebras. Then $\phi \otimes \psi$ is the coequalizer in $\mathrm{Alg}(T)$ of $T(\phi \otimes \psi)$ and $\mu \circ T(\mathrm{dst})$ (which is a reflexive pair of morphisms from the free algebra on $T(A) \otimes T(B)$ to the free algebra on $A \otimes B$). The unit $I$ in $\mathrm{Alg}(T)$ is the free algebra $\mu \colon T^2(I) \to T(I)$. Moreover, the free functor $C \to \mathrm{Alg}(T)$ preserves monoidal structure.
A good example to keep in mind is where $T$ is the free vector space monad on the category of sets. The coequalizers then is pretty much directly the usual tensor product construction with bilinear maps. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9501293897628784, "perplexity": 173.00011050521096}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-22/segments/1464049278042.30/warc/CC-MAIN-20160524002118-00025-ip-10-185-217-139.ec2.internal.warc.gz"} |
https://www.anabrid.dev/pyanalog/dirhtml/dda/intro/ | Introduction to PyDDA¶
PyDDA is a small library to write and generate DDA code in Python. DDA stands for digital differential analyzer. In this context, it is a code for solving ordinary differential equations (ODEs) given in a domain specific language description (i.e. an electrical circuit).
The main advantage of this implementation in contrast to the older Perl implementation is the abstract syntax tree level of circuit representation. The syntax tree representation allows for fine-grained manipulations of terms where the older Perl code could only apply regular expressions.
This code can replace the old dda2c.pl Perl implementation (see misc/ directory for it’s code, or also here). It is a standalone Python 3 code with no third party dependencies. It generates standalone C++ code with no dependencies (not even on the old dda.h).
Usage: As a library or from the command line¶
The dda module can either be used from a DDA file written in Python or directly from old-style traditional DDA plaintext files. While pythonic dda files have the advantage to be able to use all the flexibility of Python scripting (such as using numpy for linear algebra computations and matplotlib for postprocessing of results), plaintext DDA files are in general shorter and more precise to read. See dda.dsl for further details on the traditional DDA file format.
The module can also be used from the command line as a utility. The behaviour is similar to the simulate.pl and dda2c.pl utilities but also covers a few more features. Usage example (implementation provided by dda.dsl.cli_exporter() ):
me@localhost $python -m dda --help usage: dda.py [-h] [-o [OUTPUT]] [circuit_file] {c,dda,dot,latex} PyDDA, the AST-based DDA compiler positional arguments: circuit_file DDA setup (traditional file). Default is stdin. {c,dda,dot,latex} File formats which can be generated optional arguments: -h, --help show this help message and exit -o [OUTPUT], --output [OUTPUT] Where to write exported code to. Default is stdout. A Command Line Interface (CLI) for PyDDA... Here is a full bash script which demonstrates how to use PyDDA as a drop-in replacement for the traditional Perl-based DDA code. It allows using the PyDDA C++ code generator without writing a single line of Python: #!/usr/bin/bash # given the DDA file "notch_simplified.dda", which you can find in the # directory ./examples/traditional-dda-circuits, we simulate the system # for 2000 timesteps and plot the time evolution of the fields "cn", "cd" and "cnr" # which are part of the DDA file (in terms of "cn = int(...)") python -m dda notch_simplified.dda C --output notch_simplified.cc g++ --std=c++17 notch_simplified.cc -onotch_simplified.exe ./notch_simplified.exe --max_iterations=2000 --skip_header=1 cn cd cnr > scratch.dat cat <<GNUPLOT_FILE > gnuplot.dat set terminal pdf set output "notch_simplified_gnuplot.pdf" set key autotitle columnheader set title "Notch simplified (with PyDDA/Gnuplot)" plot "scratch.dat" using 1 with lines title "cn", \ "scratch.dat" using 2 with lines title "cd", \ "scratch.dat" using 3 with lines title "cnr" GNUPLOT_FILE gnuplot gnuplot.dat open notch_simplified_gnuplot.pdf Usage without a C++ compiler¶ The PyDDA code grew out of its predecessor (dda2c.pl) as a code generator for an ODE solver. Having C++ has target language, it requires a C++ compiler to work. However, during the time, PyDDA got mature as a toolkit for exporting the code also in different formats. In fact, using the dda.scipy module, one can avoid C++ and use PyDDA solely within the Python environment. This can be handy for anyone who cannot or does not want to deal with C++ or all the fundamentals. Therefore, instead of following all the tedious way of C++ code generation, compilation and running (which also requires that you have all the build tools installed for compiling C++ on your system), you can also take the short track by making use of SciPy, which is also much easier to install on many systems. This also works from the command line: me@localhost$ python -m dda.scipy --help
usage: scipy.py [-h] [-o [OUTPUT]] -t TFINAL [--method [METHOD]] [circuit_file]
PyDDA's scipy interface simulation runner
positional arguments:
circuit_file DDA setup (traditional file). Default is stdin.
optional arguments:
-h, --help show this help message and exit
-o [OUTPUT], --output [OUTPUT]
Where to write output CSV to. Default is stdout.
-q [QUERY_FIELDS ...], --query-fields [QUERY_FIELDS ...]
List of fields to plot. Just pass whitespace seperated (i.e. -q a b c). Also add 't' if you want
to have the solution time (recommended).
Arguments passed to scipy.integrate.solve_ivp:
-t TFINAL, --tfinal TFINAL
Time (in simulation units) to run up to. Do not confuse this with some iteration counter.
-m [METHOD], --method [METHOD]
Integration method to use
-d, --dense-output Dense Output (default is not dense)
A Command Line Interface (CLI) for :mod:dda.scipy. This CLI API basically solves a DDA file ...
Here is a shell script example, again with the notch DDA file, of using SciPy instead of the C++ based solver:
#!/usr/bin/bash
# given the DDA file "notch_simplified.dda", which you can find in the
# directory ./examples/traditional-dda-circuits, we simulate the system
# for 2000 timesteps and plot the time evolution of the fields "cn", "cd" and "cnr"
# which are part of the DDA file (in terms of "cn = int(...)")
python -m dda.scipy -d -t 20 -q cn_minus cd_minus cnr_minus --method RK45 notch_simplified.dda > scratch.dat
cat <<GNUPLOT_FILE > gnuplot.dat
set terminal pdf
set output "notch_simplified_gnuplot.pdf"
set title "Notch simplified (with PyDDA/Gnuplot)"
plot "scratch.dat" using 1 with lines title "cn", \
"scratch.dat" using 2 with lines title "cd", \
"scratch.dat" using 3 with lines title "cnr"
GNUPLOT_FILE
gnuplot gnuplot.dat
open notch_simplified_gnuplot.pdf
Note that the naming of the columns is different to the top example, since you can only access the evolution quantities, whcih are called cn_minus here, while cn is a deviated quantity. More details on these limitations can be found in the description of the dda.scipy module.
Known Bugs and limitations¶
Please see the issue list at https://github.com/anabrid/pyanalog/issues for a list of bugs.
We also have an internal bug tracker at https://lab.analogparadigm.com/software/pyanalog/-/issues which is subject to be merged into the public one. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.3032858967781067, "perplexity": 7257.3479037030465}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-49/segments/1669446710890.97/warc/CC-MAIN-20221202014312-20221202044312-00782.warc.gz"} |
https://iqrtools.intiquan.com/doc/book/installation.html | # 3 Installation
IQR Tools has been developed as a software package for the well-established and free statistical software environment R.
## 3.1 IQR Tools
install.packages("IQRtools",
repos = c("https://iqrtools.intiquan.com/rrepo","https://cran.r-project.org/"),
dependencies = TRUE)
Note that IQR Tools is currently not on CRAN - but we are working on it. Use the command above to install both IQR Tools and its dependencies.
Test your installation by executing the following:
library(IQRtools)
test_IQRtools() # Should result in a data.frame
## 3.2 Setup after installation
After the above installation, please locate the folder in which IQR Tools has been installed. In this folder there is a file called setup_options_IQRtools.R. Please have a look in this file and edit it as appropriate. It realizes the interfaces to NONMEM and MONOLIX and has other customization possibilites that might be needed on your system. You also can call the function setup_IQRtools() which will open the setup file in an editor and allow editing.
In case you do not have admin rights and the IQR Tools installation is a global one, then you can call setup_IQRtools(local=TRUE), which allows you to overwrite the global settings locally (if allowed by your system administrator).
library(IQRtools)
setup_IQRtools() | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.23203153908252716, "perplexity": 2597.1895605274913}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-43/segments/1634323585305.53/warc/CC-MAIN-20211020090145-20211020120145-00180.warc.gz"} |
https://rd.springer.com/article/10.1186/s12902-021-00685-x?error=cookies_not_supported&code=60ba73a7-d123-437c-a99e-8beca86dfc28 | # Feasibility and effectiveness of a single-catheter approach for adrenal vein sampling in patients with primary aldosteronism
## Abstract
### Background
Adrenal vein sampling (AVS) is the preferred method for subtyping patients with primary aldosteronism, while the procedure is technically challenging. This study evaluated the feasibility and effectiveness of a single-catheter approach for AVS.
### Methods
A retrospective analysis of 106 consecutive patients who underwent AVS was performed to determine the procedural success and complication rates. Bilateral AVS procedures were performed using a single 5-Fr Tiger catheter with repeated manual reshaping.
### Results
We successfully advanced the catheter into the bilateral adrenal veins of all patients and reached a 90.6% procedural success rate of AVS. The procedural period was 33.0 ± 8.2 min, the fluoroscopy period was 5.8 ± 1.7 min, and the diagnostic contrast used was 17.3 ± 5.5 ml. Only one patient (0.9%) had a hematoma at the femoral puncture site. No other complications were observed. The operation period gradually shortened as the cumulative number of operations increased. The number of procedures required to overcome the learning curve was about 33 cases.
### Conclusions
The single-catheter approach is feasible and effective for AVS. Moreover, this approach required a relatively short learning curve for an inexperienced trainee.
## Background
Approximately 44.7% of Chinese adults aged 35–75 years have hypertension, and it was estimated that 244.5 million Chinese adults experienced hypertension [1, 2]. Primary aldosteronism (PA) is the most common cause of secondary hypertension with a prevalence of at least 4% in patients with newly diagnosed hypertension in Chinese population [3]. PA is associated with increased risk of cardiovascular disease compared with patients with primary hypertension [4]. Fortunately, nearly half of patients with PA that is due to an unilateral aldosterone-producing adenoma can be cured by adrenalectomy [5]. Aldosterone-producing adenoma and bilateral idiopathic adrenocortical hyperplasia are the two most common types of PA, while patients with the latter are unsuitable for adrenalectomy but need lifelong treatment with mineralocorticoid receptor antagonists. Therefore, appropriately selecting patients for unilateral adrenalectomy is critical in the differential diagnosis and subtyping of patients with PA. The current clinical practice guidelines recommend adrenal vein sampling (AVS) as a preferred method to differentiate unilateral from bilateral PA and to select patients with PA for unilateral adrenalectomy [6,7,8].
Although AVS is accepted as the gold standard test for subtyping PA, the procedure is underused especially in underdeveloped areas partially because the AVS procedure is technically challenging and relatively expensive [9]. Due to the anatomical complexity and variations, AVS fails frequently even in experienced hands [10]. In addition, the AVS procedure can have various complications including hematoma at the puncture site, venous dissection and thrombosis, and adrenal hemorrhage and insufficiency. Previous studies reported variable success rates of the AVS procedure ranging from 40 to 94% [10,11,12]. Catheterization into the right adrenal vein is particularly difficult as it is a small and short vessel which directly drains into the inferior vena cava (IVC). Because of the distinct anatomy of the left and right adrenal veins, two different catheters are usually used in the AVS procedure, which may increase the cost of this invasive test.
As mentioned, AVS is an optimal test for differential diagnosis and subtyping of patients with PA, but it is an invasive, relatively expensive procedure with technical challenges and varied success rates. The present study aimed to evaluate the feasibility and effectiveness of a single-catheter approach for AVS in patients with PA.
## Methods
### Patients
This retrospective study was approved by the Institutional Review Board of the First Affiliated Hospital of Chengdu Medical College. All patients had given their written consent for the AVS procedure and participation in the study. We enrolled 106 consecutive patients who were diagnosed PA and underwent the AVS procedure from October 2018 to April 2020. We only used the single-catheter technique for AVS during this period of time in our center. The inclusion criteria included diagnosis of PA by clinical and laboratory examinations including saline-loading test and completion of adrenal computed tomography scan. Patients with severe hepatic and renal disorders were excluded.
### AVS procedure
Patients were prepared for the AVS procedure according to the guidelines [13]. Briefly, antihypertensive medications were switched to peripheral α1-adrenergic receptor blockers and/or long-acting calcium-channel blockers 4 weeks before the AVS procedure. Hypokalemia, if present, were corrected with potassium supplements before the procedure. The patients were kept in the supine position for 1 h before AVS. AVS was performed in the morning by two inexperienced fellows who were recently enrolled in the interventional cardiology fellowship program. A 5-Fr sheath was percutaneously placed into the right common femoral vein under local anesthesia. A 5-Fr Tiger catheter (Terumo, Tokyo, Japan) was manually reshaped for the right adrenal vein catheterization by slightly stretching the secondary and tertiary curves from 135° to 150° (Fig. 1a and b). The reshaped catheter was inserted into the IVC and then into the superior vena cava using a guidewire (0.035-in. loach guidewire, Terumo Corporation, Tokyo, Japan), and a 5 ml sample of blood was drawn from each site (Fig. 2a and b). The right adrenal vein was catheterized by attempting canalization at around the level of the eleventh thoracic vertebra (Fig. 2c). Catherization into the right adrenal vein was confirmed by angiography (Fig. 2c). After drawing a 5 ml sample of blood from the right adrenal vein, the catheter was withdrawn and manually reshaped again for the left adrenal vein catheterization by further stretching the secondary and tertiary curves from 150° to 165° (Fig. 1c). The reshaped catheter was inserted again into the IVC, and catherization into the left adrenal vein was confirmed by angiography (Fig. 2d). After drawing a 5 ml sample of blood from the right adrenal vein, the catheter was withdrawn. At the end of the procedure, the sheath was removed, and a 10 min manual compression was applied for hemostasis.
### Data collection
The demographic and laboratory data and procedural factors including period of procedure, fluoroscopy time, and procedural success and complication rates were collected from record reviewing (Table 1). The success of AVS was defined as the adrenal/peripheral vein cortisol ratio is more than 2:1 without cosyntropin.
### Statistical analysis
Continuous data are presented as mean ± standard deviation, while categorical data are presented by frequency with percentage or range. A learning curve was drawn based on a cumulative sum (CUSUM) analysis for procedure time. The operation time for each case is defined as xi, and the mean procedure time of all the cases is defined as μ. Therefore, the CUSUM at procedure time is calculated as $$\sum \limits_{i=1}^n\left( xi-u\right)$$ [14]. The CUSUM was plotted against the case number.
## Results
### Success rate of AVS procedure
The single Tiger catheter was successfully inserted into the right and left adrenal veins in all 106 patients. The success rate of bilateral AVS was 90.6% (96 out of 106) (Table 1). The procedural and fluoroscopy time was 33.0 ± 8.2 min and 5.8 ± 1.7 min, respectively (Table 1). The radiation exposure for each procedure was 117.3 ± 25.5 mGy, and the contrast agent used per procedure was 17.3 ± 5.5 ml (Table 1). Only 1 patient (0.9%) had a hematoma at the femoral puncture site. No other procedure-related complications were observed.
### Canalization of the right adrenal vein
Canalization of the right adrenal vein is critical for success of AVS but particularly challenging. The location of the right adrenal vein orifice at the IVC varies from the lower part of the tenth thoracic vertebra and the upper part of the first lumbar vertebra (Fig. 3). Most (79.2%) right adrenal veins drain into the IVC between the middle part of the eleventh thoracic vertebra and the middle part of the twelfth thoracic vertebra (Fig. 3). The angle between the right adrenal vein and the IVC is 57.3 ± 32.5 degree (ranging between 5 to 115 degree) (Fig. 4).
### Learning curve of AVS
The CUMSUM of procedure duration was plotted against case number. Among the 106 consecutive patients, the CUMSUM value inflected at patient number 33 (Fig. 5). Patients 1–32 constituted the learning phase of the curve with procedure duration of 49 ± 14 min, while patients 34–106 consisted of the experienced phase with procedure duration of 30 ± 5 min (Fig. 5).
## Discussion
This study demonstrates that the single-catheter approach is a feasible, effective, and easy-to-learn method for AVS in patients with PA. We found that the single-catheter approach achieved a procedural success rate of 90.6% for bilateral AVS with very minor complications.
Catheterization of the right adrenal vein is particularly challenging because it is a relatively small sized vein with anatomical variations. Therefore, localizing the right adrenal vein during AVS is critical for technical success. Matsuura et al. investigated the anatomy of the right adrenal vein using multidetector computed tomography and demonstrated that the orifice of the right adrenal vein was located between the level of the eleventh thoracic and the first lumbar vertebrae, with the majority at a level ranging from the middle third of the twelfth thoracic vertebra to the superior third of the first lumbar vertebra [21]. In the 106 patients enrolled in the preset study, the orifice of most right adrenal veins is slightly higher, i.e. between the middle part of the eleventh thoracic vertebra and the middle part of the twelfth thoracic vertebra. A previous study showed that the anatomical variations of the right adrenal vein based on computed tomography are highly concordant with the findings of angiography [22]. Therefore, computed tomography may provide useful information for localizing the right adrenal vein before AVS. In consistent with the previous study [21], the angle at which the right adrenal vein drains into the IVC varies between 5 to 115 degree in the present observation. As the majority of the right adrenal veins flow into the IVC with an acute angle, some groups suggested performing AVS via the forearm veins as an alternative route to the femoral vein [18].
One of the limitations is that this is a single-arm study. We could not make conclusion regarding whether the single-catheter technique is superior to or easier and cheaper than other AVS approaches. Further head-to-head comparisons are needed to answer those questions in the future. Another limitation is that pharmacological stimulation was not used during sequential AVS. Stress-induced fluctuations in cortisol and aldosterone secretion might affect the lateralization ratio. Although AVS was performed in the morning after the patients kept in the supine position for 1 h to minimize stress, it is better to apply cosyntropin stimulation before sequential AVS.
## Conclusions
In conclusion, the single-catheter approach with repeated manual reshaping provides a feasible and effective method for the AVS procedure.
## Availability of data and materials
Data relevant to this study are available from the corresponding authors upon reasonable request.
## Abbreviations
AVS:
PA:
Primary aldosteronism;
IVC:
Inferior vena cava
CUSUM:
Cumulative sum
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None.
## Funding
This research was supported by grants from the National Natural Science Foundation of China (81970262), the Central Funds Guiding the Local Science and Technology Development of Sichuan Province (2020ZYD036), the Innovation Team Project Department of Education of Sichuan Province (NO.17TD0011, 18TD0030), and Specialized Scientific Research Funding for Sichuan Center of Geriatrics (SCLNZX1808). The funding bodies played no role in the design of the study and collection, analysis, and interpretation of data and in writing the manuscript.
## Author information
Authors
### Contributions
PW designed the study and completed the writing of the paper. JW, FR, SX, JH, DW, SL, YY, and PZ collected the data and performed data analysis. All authors confirmed the final version of the paper. The author(s) read and approved the final manuscript.
### Corresponding author
Correspondence to Peijian Wang.
## Ethics declarations
### Ethics approval and consent to participate
This retrospective study was approved by the Institutional Review Board of the First Affiliated Hospital of Chengdu Medical College. All patients had given their written consent for the AVS procedure and participation in the study. The Institutional Review Board of the First Affiliated Hospital of Chengdu Medical College granted permission to access the raw data for the study.
Not applicable.
### Competing interests
All authors have no conflict of interest.
### Publisher’s Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
## Rights and permissions
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Wan, J., Ran, F., Xia, S. et al. Feasibility and effectiveness of a single-catheter approach for adrenal vein sampling in patients with primary aldosteronism. BMC Endocr Disord 21, 22 (2021). https://doi.org/10.1186/s12902-021-00685-x | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5080041289329529, "perplexity": 14849.671257493123}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-10/segments/1614178366969.45/warc/CC-MAIN-20210303134756-20210303164756-00583.warc.gz"} |
http://incubator.apache.org/npanday/docs/1.1/guide/simple_project.html | ## Creating a Simple Project
Before you start this procedure, you must have all Pre-requisites in place and have successfully completed all steps in the previous section entitled Installing and Verifying NPanday .NET Build Tool.
1. Create an empty directory for your project. For example:
``` mkdir npandaytest
cd npandaytest
```
2. From a command shell go to the directory that contains the POM file, and execute the following command (In the example, execute the command from the npandaytest directory) to create a C# or VB project:
For C#: mvn archetype:create -DgroupId=npanday -DartifactId=NPanday.Test -DarchetypeArtifactId=maven-archetype-dotnet-simple -DarchetypeGroupId=org.apache.maven.dotnet -DarchetypeVersion=[version]
For VB: mvn archetype:create -DgroupId=npanday -DartifactId=NPanday.Test -DarchetypeArtifactId=maven-archetype-vb-simple -DarchetypeGroupId=org.apache.maven.dotnet -DarchetypeVersion=[version]
The command creates the project in the NPanday.Test directory, which will now contain the following for a C# project (and a VB project will be similar with a vb directory instead of the csharp directory shown):
```.
|-- src
| `-- main
| `-- csharp
| `-- Sample
| `-- MyApp.cs
| `-- resources
| `-- test
| `-- csharp
`- pom.xml
```
3. From inside the Solution directory (NPanday.Test), execute the following command to build and install the NPanday.Test DLL files into your repository:
mvn install
The mvn install command typically puts artifacts (installs them) into the repository here, C:\Documents and Settings\[user_home]\.m2\repository.
NPanday installs the artifacts in a .NET local repository, located in C:\Documents and Settings\[user_home]\.m2\uac.
For the NPanday.Test solution the artifact is placed here, C:\Documents and Settings\[user_home]\.m2\uac\gac_msil\NPanday.Test\1.0-SNAPSHOT__NPanday\NPanday.Test.dll
The contents in C:\Documents and Settings\[user_home]\.m2\uac\gac_msil SHOULD NOT be manually modified or the project build will fail due to artifacts that are not properly indexed and are not synchronized with the repository. In case the contents have been modified, delete the C:\Documents and Settings\[user_home]\.m2\uac directory then re-install the project.
If the build fails on nunit-console see the Pre-requisites section for information on installing NUnit 2.2+ and adding it to your PATH.
4. Then clean up the target directory and download dependencies by executing:
mvn clean
5. In a command shell, still from the Solution directory (NPanday.Test in this example), execute the following command to generate the Solution:
mvn npanday.plugin:NPanday.Plugin.Solution.JavaBinding:Solution
6. This command creates the Solution file (*.sln) that corresponds to the Solution directory you just created. For example, the Solution directory was NPanday.Test, so the Solution file is NPanday.Test.sln. After you execute the command, verify the Solution directory now contains the Solution file. If so, then you are ready to load the project and solution. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9429605007171631, "perplexity": 9049.354182258467}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-22/segments/1432207932596.84/warc/CC-MAIN-20150521113212-00125-ip-10-180-206-219.ec2.internal.warc.gz"} |
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## Dido525 3 years ago The region bounded by the given curves is rotated about the specified axis. Find the volume V of the resulting solid by any method. x = (y − 5)^2, x = 4; about y = 3 I am trying to use the disc method but I am not sure how I would. Delete Cancel Submit
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1. Dido525
• 3 years ago
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Anyone want to help me set up the integral?
2. Dido525
• 3 years ago
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Anyone? :( .
3. Dido525
• 3 years ago
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Well I found the intersection points for y which are y=3 and y=7.
4. tkhunny
• 3 years ago
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Good. This is a nice problem. Have you heard of Pappus's Theorem?
5. Dido525
• 3 years ago
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No.
6. tkhunny
• 3 years ago
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Too bad. It is much simpler with the Centroid. Another lesson on another day, perhaps. The Whole thing: $$\pi\int\limits_{0}^{4}(y_{1}-3)^{2}\;dx$$ The Extra thing: $$\pi\int\limits_{0}^{4}(y_{2}-3)^{2}\;dx$$ Do you see the nature of the problem that requires two definitions for 'y'? It's NOT a function!
7. Dido525
• 3 years ago
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Yeah, I realized that.
8. tkhunny
• 3 years ago
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Perfect. What are the two definitions?
9. Dido525
• 3 years ago
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Wait you lost me. Never mind.
10. Dido525
• 3 years ago
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@tkhunny
11. tkhunny
• 3 years ago
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$$x = (y-5)^{2}$$ Solve for $$y$$. You should get TWO results.
12. Dido525
• 3 years ago
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yeah y=y-5 and y=5-y
13. Dido525
• 3 years ago
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Wait. WHat am I doing...
14. Dido525
• 3 years ago
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15. tkhunny
• 3 years ago
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?? Where did the $$x$$ go? $$\sqrt{x} = y-5\;for\;y>5$$ $$\sqrt{x} = 5-y\;for\;y<5$$ Keep solving!
16. Dido525
• 3 years ago
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|dw:1358491765588:dw|
17. Dido525
• 3 years ago
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Sorry. I had a stupid moment.
18. tkhunny
• 3 years ago
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Super. You almost beat me to it. Now, which one is on top and which one is on the bottom? These are my little y-functions.
19. Dido525
• 3 years ago
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Top function is $\sqrt{x}+5$ Bottom function is $5-\sqrt{x}$
20. tkhunny
• 3 years ago
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The Whole thing: $$\pi\int\limits_{0}^{5}((\sqrt{x}+5) −3)^{2}\;dx$$ The Extra part: Oh, you do that one!
21. Dido525
• 3 years ago
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Woudn't it be from 0 to 4?
22. tkhunny
• 3 years ago
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Yes. I just spotted that typo. Sorry about that. Good eye!
23. Dido525
• 3 years ago
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Haha thanks :) .
24. tkhunny
• 3 years ago
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25. Dido525
• 3 years ago
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136/3 which is wrong :( .
26. Dido525
• 3 years ago
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I forgot pi whoops.
27. tkhunny
• 3 years ago
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That's the whole thing. You have to subtract the small piece. That's why we had two integrals.
28. Dido525
• 3 years ago
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So it would be:$\pi \int\limits_{0}^{4}((\sqrt{x}+5)-3)^2-((5-\sqrt{x})-3)^2dx$
29. tkhunny
• 3 years ago
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That should do it. Or, you can do them as separate integrals.
30. Dido525
• 3 years ago
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THanks so much! Lets see if I get the right answer...
31. Dido525
• 3 years ago
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Yeah it's right :) . Thanks so much!
32. Dido525
• 3 years ago
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I know. I did it out on maple.
33. tkhunny
• 3 years ago
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Interestingly, if you do a little algebra, you can do a whole lot less calculus. That wonderful integrand you created simplifies to $$8\sqrt{x}$$.
34. tkhunny
• 3 years ago
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Well, for future reference, if the ENTIRE area is on one side of the axis of rotation, you can pull Pappus' Theorem out of your hat! Good luck when the time comes!
35. Dido525
• 3 years ago
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When I learn it XD .
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http://clay6.com/qa/28711/a-current-carrying-wire-is-kept-along-a-magnetic-line-of-force-the-force-ex | Browse Questions
# A current carrying wire is kept along a magnetic line of force. The force experienced by the wire due to the magnetic field is
$\begin {array} {1 1} (a)\;In\: the \: direction\: of \: the\: magnetic \: field \\ (b)\;In \: the\: direction\: opposite\: to\: the\: magnetic \: field \\ (c)\;In \: the \: direction\: perpendicular\: to\: the\: magnetic\: field \\ (d)\;Zero \end {array}$
Angle between the current and the field is zero
Ans : (d) | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 2, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5837380886077881, "perplexity": 522.4209025112716}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-17/segments/1492917121000.17/warc/CC-MAIN-20170423031201-00296-ip-10-145-167-34.ec2.internal.warc.gz"} |
https://www.physicsforums.com/threads/confusion-with-time-dialation.609085/ | # Confusion with time dialation.
1. May 26, 2012
### MartinJH
Reading Brian Cox and Jeff Forshaw's book "Why does E=MC2". They mention that satellites speed up with time, but, then reading Wiki it says the crew of the ISS experience the slowing of time. Which one is correct? I'm slightly confused.
Both experience a weaker gravitational pull and high velocities.
Could it be the overall difference in altitude and speed?
Many thanks
http://en.wikipedia.org/wiki/Time_dilation
Last edited: May 26, 2012
2. May 26, 2012
### Naty1
3. May 26, 2012
### yuiop
The velocity based time dilation combined with the gravitational time dilation can be written as:
$$\sqrt{1-\frac{v^2}{c^2}} * \sqrt{1-\frac{2GM}{rc^2}}$$
Since the orbital velocity of a satellite is given by:
$$v = \sqrt{\frac{GM}{r}}$$
then the first equation can be rewritten as:
$$\sqrt{1-\frac{GM}{rc^2}} * \sqrt{1-\frac{2GM}{rc^2}}$$
It can be seen for increasing radius the time dilation reduces due to increased height and due to reduced orbital velocity. Clocks on satellites with large orbits tick faster than clocks on satellites at lower orbits. Clocks on the surface of the Earth are moving much slower than the required orbital velocity at that radius and so tick faster than clocks on satellites with very low orbits. The ISS has a relatively low orbit (its radius is approximately 1.05 times the radius of the Earth), so clocks on the ISS are indeed ticking slower than clocks on the surface of the Earth. The speed up of clocks with increasing radius means that once an orbital radius is larger than 3 times the Earth surface radius (the break even point) the clocks on board a satellite are ticking faster than a clock on the Earth surface. The GPS satellites have an orbital radius of about 4.1 times the radius of the Earth so they are ticking faster.
P.S. The above equations for the time dilation of an orbiting satellite can be fairly accurately approximated in this case by:
$$\sqrt{1-\frac{3GM}{rc^2}} or \left(1-\frac{3GM}{2rc^2}\right)$$
4. May 26, 2012
### MartinJH
Thank you, yuiop. You have hit the nail on the head.
Since I posted the question, a few hours ago, I have been pondering over it and knew their had to be a explanation. From reading your post it looks like I was touching on the reason but couldn't quite grasp it.
Thank you for your post also, Naty1.
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https://www.rdocumentation.org/packages/incidence/versions/1.7.1/topics/fit | # fit
0th
Percentile
##### Fit exponential models to incidence data
The function fit fits two exponential models to incidence data, of the form: $log(y) = r * t + b$ where 'y' is the incidence, 't' is time (in days), 'r' is the growth rate, and 'b' is the origin. The function fit will fit one model by default, but will fit two models on either side of a splitting date (typically the peak of the epidemic) if the argument split is provided. When groups are present, these are included in the model as main effects and interactions with dates. The function fit_optim_split() can be used to find the optimal 'splitting' date, defined as the one for which the best average R2 of the two models is obtained. Plotting can be done using plot, or added to an existing incidence plot by the piping-friendly function add_incidence_fit().
##### Usage
fit(x, split = NULL, level = 0.95, quiet = FALSE)fit_optim_split(
x,
window = x$timespan/4, plot = TRUE, quiet = TRUE, separate_split = TRUE )# S3 method for incidence_fit print(x, ...)# S3 method for incidence_fit_list print(x, ...) ##### Arguments x An incidence object, generated by the function incidence(). For the plotting function, an incidence_fit object. split An optional time point identifying the separation between the two models. If NULL, a single model is fitted. If provided, two models would be fitted on the time periods on either side of the split. level The confidence interval to be used for predictions; defaults to 95%. quiet A logical indicating if warnings from fit should be hidden; FALSE by default. Warnings typically indicate some zero incidence, which are removed before performing the log-linear regression. window The size, in days, of the time window either side of the split. plot A logical indicating whether a plot should be added to the output (TRUE, default), showing the mean R2 for various splits. separate_split If groups are present, should separate split dates be determined for each group? Defaults to TRUE, in which separate split dates and thus, separate models will be constructed for each group. When FALSE, the split date will be determined from the pooled data and modelled with the groups as main effects and interactions with date. ... currently unused. ##### Value For fit(), a list with the class incidence_fit (for a single model), or a list containing two incidence_fit objects (when fitting two models). incidence_fit objects contain: • $model: the fitted linear model
• $info: a list containing various information extracted from the model (detailed further) • $origin: the date corresponding to day '0'
The $info item is a list containing: • r: the growth rate • r.conf: the confidence interval of 'r' • pred: a data.frame containing predictions of the model, including the true dates (dates), their numeric version used in the model (dates.x), the predicted value (fit), and the lower (lwr) and upper (upr) bounds of the associated confidence interval. • doubling: the predicted doubling time in days; exists only if 'r' is positive • doubling.conf: the confidence interval of the doubling time • halving: the predicted halving time in days; exists only if 'r' is negative • halving.conf: the confidence interval of the halving time For fit_optim_split, a list containing: • df: a data.frame of dates that were used in the optimization procedure, and the corresponding average R2 of the resulting models. • split: the optimal splitting date • fit: an incidence_fit_list object containing the fit for each split. If the separate_split = TRUE, then the incidence_fit_list object will contain these splits nested within each group. All of the incidence_fit objects can be retrieved with get_fit(). • plot: a plot showing the content of df (ggplot2 object) ##### See Also the incidence() function to generate the 'incidence' objects. The get_fit() function to flatten incidence_fit_list objects to a list of incidence_fit objects. ##### Aliases • fit • fit_optim_split • print.incidence_fit • print.incidence_fit_list ##### Examples # NOT RUN { if (require(outbreaks)) { withAutoprint({ dat <- ebola_sim$linelist$date_of_onset ## EXAMPLE WITH A SINGLE MODEL ## compute weekly incidence i.7 <- incidence(dat, interval=7) plot(i.7) plot(i.7[1:20]) ## fit a model on the first 20 weeks f <- fit(i.7[1:20]) f names(f) head(get_info(f, "pred")) ## plot model alone (not recommended) plot(f) ## plot data and model (recommended) plot(i.7, fit = f) plot(i.7[1:25], fit = f) ## piping versions if (require(magrittr)) { withAutoprint({ plot(i.7) %>% add_incidence_fit(f) ## EXAMPLE WITH 2 PHASES ## specifying the peak manually f2 <- fit(i.7, split = as.Date("2014-10-15")) f2 plot(i.7) %>% add_incidence_fit(f2) ## finding the best 'peak' date f3 <- fit_optim_split(i.7) f3 plot(i.7) %>% add_incidence_fit(f3$fit)
})}
})}
# }
Documentation reproduced from package incidence, version 1.7.1, License: MIT + file LICENSE
### Community examples
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http://math.stackexchange.com/questions/152129/algebra-simplify-question | # Algebra simplify question?
How would I simplify this?
$$5\% \cdot \frac12 \left(3000 + 2x\right)$$
-
My book says it is 165+.11x but I am not sure how – James May 31 '12 at 18:02
First step: write the expression in symbols, then we can give you hints. – rschwieb May 31 '12 at 18:05
You have: $0.05\cdot0.5(3000+2x)=0.025\cdot(3000+2x)=75+0.05x$
-
Assuming this is what you mean:
$$5\%*\frac{1}{2}*(3000+2x)$$
I assume you know that $5\%=\frac{5}{100}=\frac{1}{20}$. So we have
$$\frac{1}{40}*(3000+2x)=\frac{3000}{40}+\frac{2x}{40}=75+\frac{x}{20}$$
-
$$0.11\cdot\frac{1}{2}(3000+2x)$$
I would reduce this by distributing the 1/2 first: $$0.11(1500+x)$$ Then distribute the .11, using the trick $.11(1500)=.11(100)15=11(15)=165$ to get $$165+.11x$$ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9843727350234985, "perplexity": 1859.6438536437247}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-15/segments/1397609525991.2/warc/CC-MAIN-20140416005205-00328-ip-10-147-4-33.ec2.internal.warc.gz"} |
https://www.physicsforums.com/threads/getting-the-wrong-multipole-for-1st-acoustic-peak.923207/ | # I Getting the wrong multipole for 1st acoustic peak
1. Aug 19, 2017
### DoobleD
I'm trying to do a simple calculation, but there must be something wrong.
The wavelength $\lambda_1$ corresponding to first acoustic peak of the CMB is related to the sound horizon at last scattering, $d_{hs}$, by :
$\lambda_1 = 2d_{hs}$ (see for instance slide 14 on Wayne Hu PDF slides).
Now, the multipole $l$ of the first acoustic peak can be related to its wavelength and to the distance to last scattering surface, $D$, by :
$l_1 = \frac{2 \pi}{\lambda_1} D$ (see slide 15)
From that I deduce the following equation :
$l_1 = \frac{\pi}{d_{hs}}D$
I find in the litterature that $D \approx 14000 Mpc$, and $d_{hs} \approx 150 Mpc$. I plug those values into the previous equation, and I find $l_1 \approx 293$, which is quite far from the $l_1 \approx 200$ I should get for the first peak. What's wrong ?
2. Aug 19, 2017
### DoobleD
I get the values for distance to last scattering surface and sound horizon here. I wonder however if 150 Mpc for the sound horizon is not in comoving coordinates, while I should use the physical distance instead (which I don't know) ?
EDIT : I just realized that at the very end of that WMAP values document, they basically give the exact same formula, $l = \frac{\pi}{d_{hs}}D$. And with the values they gives, I get $l = 299$. Why am I not getting 200 ?
Last edited: Aug 19, 2017
3. Aug 19, 2017
### DoobleD
4. Aug 21, 2017
5. Sep 5, 2017
### DoobleD
Thank you for the help. I'm still puzzled by my problem, but great article. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9197881817817688, "perplexity": 818.2220421091004}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-13/segments/1521257650993.91/warc/CC-MAIN-20180324190917-20180324210917-00123.warc.gz"} |
https://diophantus.org/arxiv/0704.0043 | # diophantus
Hello, this is beta version of diophantus. If you want to report about a mistake, please, write to [email protected]
#### Nonequilibrium entropy limiters in lattice Boltzmann methods
31 Mar 2007 cond-mat.stat-mech, cond-mat.mtrl-sci arxiv.org/abs/0704.0043
Abstract. We construct a system of nonequilibrium entropy limiters for the lattice Boltzmann methods (LBM). These limiters erase spurious oscillations without blurring of shocks, and do not affect smooth solutions. In general, they do the same work for LBM as flux limiters do for finite differences, finite volumes and finite elements methods, but for LBM the main idea behind the construction of nonequilibrium entropy limiter schemes is to transform a field of a scalar quantity - nonequilibrium entropy. There are two families of limiters: (i) based on restriction of nonequilibrium entropy (entropy "trimming") and (ii) based on filtering of nonequilibrium entropy (entropy filtering). The physical properties of LBM provide some additional benefits: the control of entropy production and accurate estimate of introduced artificial dissipation are possible. The constructed limiters are tested on classical numerical examples: 1D athermal shock tubes with an initial density ratio 1:2 and the 2D lid-driven cavity for Reynolds numbers Re between 2000 and 7500 on a coarse 100*100 grid. All limiter constructions are applicable for both entropic and non-entropic quasiequilibria.
# Reviews
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https://www.physicsforums.com/threads/equations-of-motion-help.79162/ | # Equations of Motion Help
1. Jun 15, 2005
### nissanfreak
Equations of Motion Help!!!
I have been working on this for awile and still cant figure it out. What equation would I use to solve this problem? Here is the problem:
On a ride called the Detonator at Worlds of Fun in Kansas City, passengers accelerate straight downward from zero to 45 mi/h in 1.0 seconds. What is the average acceleration of the passengers on this ride?
Any and all help would be greatly appreciated!
2. Jun 15, 2005
### OlderDan
This is a direct application of the definition of acceleration. No other equations are needed. You might need to do a unit conversion to match your answer to a given answer. The natural units that come from the information given would be miles per hour per second, but a book answer might be feet per second per second or feet per second squared. Other possibilities exist.
3. Jun 15, 2005
### nissanfreak
The answer in the back of the book is 20.1 m/s^2 I just dont know how they got that? Can you help me figure this out!!! Thanks in advance!!!!
4. Jun 15, 2005
### WhirlwindMonk
It's just unit conversions. The acceleration is 45 miles/hour/second, and when converted, it gives you 20.1 meters/second^2
5. Jun 15, 2005
### whozum
First thing you're going to do is convert to metric units.
edit: I give up, it won't show up right.
Fill in hte proper conversion for each then multiply out. You'll get 20.1m/s^2
Last edited: Jun 15, 2005
6. Jun 15, 2005
### nissanfreak
Yea I was trying it out but it doesnt want to come out right. I believe I need to use one of the constant-acceleration equations of motion. But im not sure which one? And how to plug the info into the equation?
7. Jun 15, 2005
### WhirlwindMonk
I did it and got the correct answer. Well, my calculator did it. You are either using incorrect conversions or doing a conversion wrong.
1 mile = 1609.344 meters
1 hour = 3600 seconds
8. Jun 15, 2005
### nissanfreak
can you show me how you multiplied it? I really appreciate it!!!
9. Jun 15, 2005
### WhirlwindMonk
45 mile/(hr*s) * 1 hr/3600 s = 0.0125 mile/s^2
.0125 mi/s^2 * 1609.344 m/1 mile = 20.1 m/s^2
10. Jun 15, 2005
### nissanfreak
Thank you for your help!!! I do however have one last question. Would you be able find this answer 20.1m/s^2 if you didnt know that it was the answer? Sorry if this sounds dumb but I have only had 4 physics classes. Im taking a 5 week course this summer over physics so I am fairly new to all of this. Thanks again everyone for the help!!!!! :)
11. Jun 15, 2005
### WhirlwindMonk
Yes, I definately could have. All it is is a goofy unit conversion problem. One thing I learned from my AP physics class is that you need to keep with it and ask for help if you need it. Once you get the concepts, physics is really cool and a lot of fun. Until then...let's just say i still have bruises from banging my head against my desk. :tongue:
12. Jun 16, 2005
### OlderDan
Yes you would be able to find that answer, but there is no way you would have known that you were supposed to express it in that form unless the question told you to do so. Miles per hour per second is a prefectly reasonable unit for expressing acceleration. It is the natural unit when speed is given in miles per hour and changing rapidly, such as for objects like the one in your problem or accelerating cars like dragsters. Don't feel bad about not anticipating the form of the answer you were given if the problem did not tell you to express it that way. Just make sure you understand how to do unit conversions when required.
You should notice that WhirlwindMonk accomplished the unit conversion by a series of multiplications by factors equal to 1. All unit conversions should be done that way. The ratio of two equal quantities is always 1. All you need to do is write the fraction in the form that is going to cancel the units you want replaced and leave you with the units you want. Sometimes it takes several steps to accomplish that. I am going to rewrite what you were already told, but in more detail, to emphasize this point.
$$a = \frac{{45\frac{{mi}}{h}}}{{1s}} = \frac{{45mi}}{{hs}}\left( {\frac{{5280ft}}{{mi}}} \right)\left( {\frac{{12in}}{{ft}}} \right)\left( {\frac{{2.54cm}}{{in}}} \right)\left( {\frac{{1m}}{{100cm}}} \right)\left( {\frac{1 h}{{60\min }}} \right)\left( {\frac{{1\min }}{{60{\mathop{\rm s}\nolimits} }}} \right) = 20.1\frac{m}{{s^2 }}$$
Every fraction in parentheses has the value 1 because the numerator and denominator are equal.
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https://koreascience.or.kr/search.page?keywords=convergence+theory&pageSize=10&pageNo=99 | • Title, Summary, Keyword: convergence theory
### Vitalization Strategy Research of Private Modern Dance Organizations: Centered on The Importance of Experts and Urgency Assessment (민간 현대무용단의 활성화 전략 연구: 전문가 중요도 및 시급성 평가를 중심으로)
• Kim, Gyu-Jin
• Journal of Digital Convergence
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• v.18 no.11
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• pp.527-538
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• 2020
• This research measures the urgency and importance listening to experts' opinions as a proposal for vitalization of folk modern dance groups. Firstly, the open type FGI(Focus Group Interview) was implemented for five groups of an expert by applying the new industry foster theory, and total 24 types of second questionnaire were developed through importantly referred or repeated contents. They were distributed to 20 people including a dance group representative, a planner, a university professor and etc to measure experts' importance and urgency. In the research result, For big list, Financial aid for both importance and urgency appear first, and for comparative analysis of importance and urgency for small list, differences in infrastructure construction are shown. "expansion of dance program's advertisement channels" and "rank 1" appeared in "Secure space for dancers". Suggestions for analyzing such results are as follows. It is shown that "detailed financial aid for the operation of dance groups" and etc in the aspect of financial aid, "the employment of professional human resources including design and producing etc" in that of performance and education related production development, "training a dancer who can assimilate a complex genre" in that of manpower training, "arrangement of exclusive space for a dance group" in that of infrastructure building, and "the employment of professional human resources including design and producing etc" in that of consulting support are important and urgent matters considered by experts.
### Sino-Globalization Network of Chinese Migrants, Students, and Travellers (중국 이민자, 유학생, 여행자를 통해서 본 세계화 네트워크)
• Zhu, Yupeng;Park, Hyejin;Park, Han Woo
• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.509-517
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• 2020
• This study examined Sino-globalization through the network analysis of Chinese immigrants, international students, and travelers. The data were collected from the United Nations for immigrants, UNESCO for international students, and Ministry of Culture and Tourism of China for travelers. Consequently, Chinese immigrants and international students' favorite destinations were advanced Western countries, and Chinese travelers showed a high preference for Asian regions. Specifically, Thailand was the most popular destination for traveling, while the U.S. appeared to be the main destination for Chinese immigrants and students. The QAP analysis results showed a statistically significant correlation between the immigrant network and international student network. MR-QAP analysis found a causal relationship between the two networks. These findings may serve as empirical evidence for the Chinese government to review potential opportunities and problems related to Sino-globalization and provide the basis for preparing policy measures for other countries. Subsequent studies should compensate for research limitations by analyzing specific factors affecting national choice of Chinese immigrants, students, and travelers. The economic, social, and cultural impacts of China's globalization on other countries need to be discussed using qualitative research.
### A study on the analysis of the offshoring(overseas expansion) of foreign companies and the reshoring(return to home country) of domestic companies in the US market (미국시장의 해외 기업의 오프쇼어링(해외진출) 및 자국기업의 리쇼어링(본국회귀) 현상 분석에 관한 연구)
• Lee, Kang-Sun;Choi, Kyu-Jin;Cho, Dae-myeong
• Journal of Digital Convergence
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• v.18 no.12
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• pp.183-193
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• 2020
• This study attempts to interpret the causes of offshoring and reshoring, find out facilitating factors and the areas where these happen mainly. In viewpoint of self-organization phenomena, the theory of prospect, quantitative analysis is performed by utilizing actual data of American Reshoring Association. This study shows that offshoring to the U.S. is positively correlated with market power in the U.S. and innovation of investment countries, while reshoring to U.S. is positively correlated with market power in the U.S. not with technology innovation. The reshoring of U.S. companies is influencing offshoring to U.S, emerging countries such as Asia tends to focus offshoring in short catch up cycle area like IT. This study is expected to contribute to investment support policy and decision for optimal production site. Further study will complete the economic benefit assessment model by reinforcing the impact factors of reshoring and offshoring.
### Unlim Yechan's Thoughts and his literati paintings land (운임(雲林) 예찬(倪瓚)의 사상(思想)과 그의 문인화(文人畵) 경계(境界))
• Kwon, Yun Hee
• The Journal of the Convergence on Culture Technology
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• v.6 no.4
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• pp.419-427
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• 2020
• Ye-chan(倪瓚) is one of the four great masters of the Yuan. He built his own unique art world under the rule of the times under the rule of immigrahts. His theory of painting, i-ch'i(逸氣) in the heart, is a spiritual product made up of the influence of traditional oriental thoughts such as Confucian scholar(儒), Buddhism(佛), and Zen Buddhism(禪). The i-ch'i is a new awareness of nature that has arisen between literary noblemen(文人士大夫) under the influence of freshness(淸淡), emptiness(虛無), non-action(無爲). This is beyond the mundane world and became the theoretical basis for literati painting. The i-pi(逸筆) of Ye-chan is a method of drawing the i-ch'i in the heart. This is the boundary of his literati painting obtained through his long efforts and practice. Ye-chan realized the high ground of unity of poem and calligraphy(詩書一體) and unity of poem and Zen(詩禪一致), which he realized in his daily life.His artistic spirit expressed the high level of staying away from being clean(脫俗遠塵), doing not stay in one place(一所不住), and unity of poem and calligraphy(詩書一体). Through this, he built a unique world of literati painting in the Art World of the late Yuan and early Ming dynasty.
### The Effect of Large Company's Corporate Social Responsibility on the Trust and Relationship Commitment of Supplier Company's Workers (대기업의 사회적 책임활동이 협력회사 구성원의 신뢰와 관계몰입에 미치는 영향)
• Lee, Yang-Soo;Kim, Byeong-Seong;Kim, Hae-Ryong
• Journal of Digital Convergence
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• v.18 no.7
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• pp.201-213
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• 2020
• The purpose of this study is to examine the effects of large company's corporate social responsibility(CSR) on trust and relationship commitment of partner companies' members. This study is different from previous studies with respect to inclusion of safety/environment responsibility as one of CSR components and inclusion of supplier company's members as one of major stakeholders in CSR. Corporate social responsibility activities, which are independent variables, are composed of four components: economic, legal, ethical, and safety/environment responsibility. The trust is composed of the dependent variables as the parameter. For the empirical analysis, data were collected from 186 members of supplier companies of 'S' large companies. The data collected were analyzed using SPSS 21.0 and AMOS 21.0 to verify the hypothetical relationship. The results of this study are as follows. First, social responsibility activities have an effect on trust and relationship commitment, and trust has a positive effect on relationship commitment. In the relationship between social responsibility activities and relationship commitment, trust was found to play a full mediating role. Based on these results, implications were discussed in terms of theory and practice, limitations were pointed out, and some research directions for future research were also proposed.
### Exploring the Online Learning Experience of College Students Majoring Physical Education in the COVID-19 Pandemic (코로나-19 팬데믹으로 인한 체육계열 대학생의 원격수업 학습경험 탐색)
• Lee, Man-Gi;Cho, Eunbyul;Lim, Hyosung
• Journal of Digital Convergence
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• v.19 no.1
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• pp.421-430
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• 2021
• The study was conducted to examine the educational experiences and perceptions of college students in the field of physical education as they were taken remote classes in university due to the effects of the social collective infection caused by COVID-19. To achieve the purpose of the study, an online survey was conducted on 278 university students who major in physical education, and the survey questions include the status of remote classes, remote class recognition (preference, and satisfaction level). As for the analysis method, frequency analysis, response sample t-verification, ANOVA, and word-cradle were performed using SPSS 22.0 and R programs, and all significance levels were set at .05. The results from the above research process are as follows. First, in the types of remote classes in the sports category due to COVID-19, video types were used the most in both theoretical and practical classes, and the following was shown as assignment types. The third type was the voice record lecture type for theoretical classes, and the practical class was the video lecture scene. Second, in the remote class preference for the students, both theory and practical classes, video format were the most prefered, followed by video lecture scene and voice lecture type. Third, the analysis of the differences in satisfaction between theoretical and practical classes of the students showed that there was no difference in satisfaction according to the type of class.
### The Development of Predictive Multiclass Dynamic Traffic Assignment Model and Algorithm (예측적 다중계층 동적배분모형의 구축 및 알고리즘 개발)
• Kang, Jin-Gu;Park, Jin-Hee;Lee, Young-Ihn;Won, Jai-Mu;Ryu, Si-Kyun
• Journal of Korean Society of Transportation
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• v.22 no.5
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• pp.123-137
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• 2004
• The study on traffic assignment is actively being performed which reflect networks status using time. Its background is increasing social needs to use traffic assignment models in not only hardware area of road network plan but also software area of traffic management or control. In addition, multi-class traffic assignment model is receiving study in order to fill a gap between theory and practice of traffic assignment model. This model is made up of two, one of which is multi-driver class and the other multi-vehicle class. The latter is the more realistic because it can be combined with dynamic model. On this background, this study is to build multidynamic model combining the above-mentioned two areas. This has been a theoretic pillar of ITS in which dynamic user equilibrium assignment model is now made an issue, therefore more realistic dynamic model is expected to be built by combining it with multi-class model. In case of multi-vehicle, FIFO would be violated which is necessary to build the dynamic assignment model. This means that it is impossible to build multi-vehicle dynamic model with the existing dynamic assignment modelling method built under the conditions of FIFO. This study builds dynamic network model which could relieve the FIFO conditions. At the same time, simulation method, one of the existing network loading method, is modified to be applied to this study. Also, as a solution(algorithm) area, time dependent shortest path algorithm which has been modified from existing shortest path algorithm and the existing MSA modified algorithm are built. The convergence of the algorithm is examined which is built by calculating dynamic user equilibrium solution adopting the model and algorithm and grid network.
### Exact Solutions for Vibration and Buckling of Rectangular Plates Loaded at Two Simply-Supported Opposite Edges by In-Plane Moments, Free along the Other Two Edges (면내(面內) 모멘트를 받는 단순지지된 두 모서리와 자유경계인 나머지 두 모서리를 갖는 직사각형 판의 진동과 좌굴의 엄밀해)
• Shim, Hyun-Ju;Woo, Ha-Young;Kang, Jae-Hoon
• Journal of Korean Association for Spatial Structures
• /
• v.6 no.4
• /
• pp.81-92
• /
• 2006
• This paper presents exact solutions for the free vibrations and buckling of rectangular plates having two opposite, simply supported edges subjected to linearly varying normal stresses causing pure in-plane moments, the other two edges being free. Assuming displacement functions which are sinusoidal in the direction of loading (x), the simply supported edge conditions are satisfied exactly. With this the differential equation of motion for the plate is reduced to an ordinary one having variable coefficients (in y). This equation is solved exactly by assuming power series in y and obtaining its proper coefficients (the method of Frobenius). Applying the free edge boundary conditions at y=0, b yields a fourth order characteristic determinant for the critical buckling moments and vibration frequencies. Convergence of the series is studied carefully. Numerical results are obtained for the critical buckling moments and some of their associated mode shapes. Comparisons are made with known results from less accurate one-dimensional beam theory. Free vibration frequency and mode shape results are also presented. Because the buckling and frequency parameters depend upon Poisson's ratio ( V ), results are shown for $0{\leq}v{\leq}0.5$, valid for isotropic materials.
### A Comprehensive Groundwater Modeling using Multicomponent Multiphase Theory: 1. Development of a Multidimensional Finite Element Model (다중 다상이론을 이용한 통합적 지하수 모델링: 1. 다차원 유한요소 모형의 개발)
• Joon Hyun Kim
• Journal of Korea Soil Environment Society
• /
• v.1 no.1
• /
• pp.89-102
• /
• 1996
• An integrated model is presented to describe underground flow and mass transport, using a multicomponent multiphase approach. The comprehensive governing equation is derived considering mass and force balances of chemical species over four phases(water, oil, air, and soil) in a schematic elementary volume. Compact and systemati notations of relevant variables and equations are introduced to facilitate the inclusion of complex migration and transformation processes, and variable spatial dimensions. The resulting nonlinear system is solved by a multidimensional finite element code. The developed code with dynamic array allocation, is sufficiently flexible to work across a wide spectrum of computers, including an IBM ES 9000/900 vector facility, SP2 cluster machine, Unix workstations and PCs, for one-, two and three-dimensional problems. To reduce the computation time and storage requirements, the system equations are decoupled and solved using a banded global matrix solver, with the vector and parallel processing on the IBM 9000. To avoide the numerical oscillations of the nonlinear problems in the case of convective dominant transport, the techniques of upstream weighting, mass lumping, and elementary-wise parameter evaluation are applied. The instability and convergence criteria of the nonlinear problems are studied for the one-dimensional analogue of FEM and FDM. Modeling capacity is presented in the simulation of three dimensional composite multiphase TCE migration. Comprehesive simulation feature of the code is presented in a companion paper of this issue for the specific groundwater or flow and contamination problems.
### Flexural and Buckling Analysis of Laminated Composite Beams with Bi- and Mono-Symmetric Cross-Sections (이축 및 일축 대칭단면 적층복합 보의 휨과 좌굴해석)
• Hwoang, Jin-Woo;Back, Sung Yong
• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.12
• /
• pp.614-621
• /
• 2019
• A generalized laminated composite beam element is presented for the flexural and buckling analysis of laminated composite beams with double and single symmetric cross-sections. Based on shear-deformable beam theory, the present beam model accounts for transverse shear and warping deformations, as well as all coupling terms caused by material anisotropy. The plane stress and plane strain assumptions were used along with the cross-sectional stiffness coefficients obtained from the analytical technique for different cross-sections. Two types of one-dimensional beam elements with seven degrees-of-freedom per node, including warping deformation, i.e., three-node and four-node elements, are proposed to predict the flexural behavior of symmetric or anti-symmetric laminated beams. To alleviate the shear-locking problem, a reduced integration scheme was employed in this study. The buckling load of laminated composite beams under axial compression was then calculated using the derived geometric block stiffness. To demonstrate the accuracy and efficiency of the proposed beam elements, the results based on three-node beam element were compared with those of other researchers and ABAQUS finite elements. The effects of coupling and shear deformation, support conditions, load forms, span-to-height ratio, lamination architecture on the flexural response, and buckling load of composite beams were investigated. The convergence of two different beam elements was also performed. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.4306298792362213, "perplexity": 4855.07519275079}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-31/segments/1627046153980.55/warc/CC-MAIN-20210730185206-20210730215206-00404.warc.gz"} |
http://djnavarro.net/post/strings-and-substititions/ | # Day 11: Strings and substitutions
### by Danielle Navarro, 07 May 2018
I’m not well today. I’ve been coughing all day and I’d intended to do something absurd with this post to make me feel better. In between sending work emails, I tried playing around with the cowsay andfortunes packages (link). I tried playing minecraft using the fun package (link). It was all to no avail: I failed to work up any enthusiasm for any it.
The only thing that has given me joy all day is the realisation that yes, Dani, there is a janeaustenr package. It contains the text to all the Jane Austen novels ❤️ 💕 What’s that you say? All of Jane Austen novels?
Yay! Now I have something nerdy to do that is fun … I will play around with the text of Pride and Prejudice while (finally!) taking a look at stringr. So, let’s do this! First, I’ll need one Jane Austen novel please!
pp <- janeaustenr::prideprejudice
pp[1:11]
## [1] "PRIDE AND PREJUDICE"
## [2] ""
## [3] "By Jane Austen"
## [4] ""
## [5] ""
## [6] ""
## [7] "Chapter 1"
## [8] ""
## [9] ""
## [10] "It is a truth universally acknowledged, that a single man in possession"
## [11] "of a good fortune, must be in want of a wife."
Check ✅ Next, I’ll need one text manipulation package:
library(stringr)
That’s another check! ✅ ✅ Yay!!!!
## What am I hoping for here?
I suppose I should ask myself what my goals are, besides trying to distract myself from the fact that my lungs are filling with fluid. I mean, a lot of the stringr package feels very familiar, with analogs of many core R functions that I learned way back in the pre-Snapchat era before people started telling me that I had to switch to tidyverse.
My understanding is that stringr isn’t really intended to provide “new” functionality to R, exactly, but it is supposed to be a more convenient collection of tools with a more consistent structure. I’ve got no illusions. Regular expressions are the bane of my existence, and I doubt that stringr is going to make them any less awful. But if we can keep everything else about text manipulation as painless as possible, I’ll be very very happy! Plus I have Jane Austen to keep me happy! 🎈
Oh. 😭
## First impressions
Jane Austen’s pointed commentary on my self-worth notwithstanding, I’m really happy upon looking at the documentation 📚. It’s really nicely structured. To quote straight from the package vignette:
There are four main families of functions in stringr:
• Character manipulation: these functions allow you to manipulate individual characters within the strings in character vectors.
• Whitespace tools to add, remove, and manipulate whitespace.
• Locale sensitive operations whose operations will vary from locale to locale.
• Pattern matching functions. These recognise four engines of pattern description. The most common is regular expressions, but there are three other tools.
… that’s promising! I guess I’ll just follow the vignette then 😸 and try out each category one at a time.
## Character manipulation
I feel like there’s an obvious joke to be made here about manipulative Jane Austen characters, but nothing is coming to mind, a sure sign that the viral infection has crossed the blood-brain barrier and I’m losing my mind. Neverthelesss…
As one might expect, the str_length function returns the length of a string, much like nchar in the base packages:
titletext <- c("Pride and Prejudice", "by Jane Austen")
str_length(string = titletext)
## [1] 19 14
The str_sub function is used to extract substrings from the string, and replace them with new values. In this function the substring is defined by the start and end of the substring:
str_sub(string = titletext, start = 4, end = 12)
## [1] "de and Pr" "Jane Aust"
So far, nothing too surprising. No wait, I tell a lie … you can use negative indices to define a position relative to the right edge of the string. So this would let me grab the last 8 characters of the string:
str_sub(string = titletext, start = -8, end = -1)
## [1] "rejudice" "e Austen"
Ooh that is very nice. You can also replace text using str_sub. So in this instance I can truncate the strings at 5 characters and then append "..."
str_sub(string = titletext, start = 6) <- "..."
titletext
## [1] "Pride..." "by Ja..."
Finally, the str_dup function lets you replicate the content within a string. So either of these works:
str_dup(string = titletext, times = 2)
str_dup(string = titletext, times = c(2,4))
## [1] "Pride...Pride..." "by Ja...by Ja..."
## [1] "Pride...Pride..." "by Ja...by Ja...by Ja...by Ja..."
Very nice, but on the other hand I’ve now started to have horrible flashbacks to traumatic text manipulation exercises, so if you’ll excuse me for a moment…
### Whitespace manipulation
… and we’re back! The str_pad function adds whitespace padding to ensure that the string reaches a particular length:
str_pad(string = titletext, width = 20)
str_pad(string = titletext, width = 20, side = "right")
str_pad(string = titletext, width = 20, side = "both")
str_pad(string = titletext, width = 20, side = "both", pad = "-")
## [1] " Pride..." " by Ja..."
## [1] "Pride... " "by Ja... "
## [1] " Pride... " " by Ja... "
## [1] "------Pride...------" "------by Ja...------"
Combining str_pad and str_trunc means that you can force strings to be exactly a desired length, but padding one and truncating the other. Similarly, you can use str_trim to remove padding from one or both sides. For me favourite of these functions, it’s a toss up between (a) str_squish, which removes all excess white space, whether it be leading, middle or trailing…
titletext <- " Pride and Prejudice
by Jane Austen "
str_squish(titletext)
## [1] "Pride and Prejudice by Jane Austen"
or (b) str_wrap, which tries to modify the white space to ensure that every line is approximately the same width:
ppstart <- "Pride and Prejudice by Jane Austen. It is a truth universally acknowledged, that a single man in possession of a good fortune, must be in want of a wife."
cat(str_wrap(string = ppstart, width = 20))
## Pride and Prejudice
## by Jane Austen.
## It is a truth
## universally
## acknowledged, that
## a single man in
## possession of a good
## fortune, must be in
## want of a wife.
It even lets you specify the indent and exdent of the output string, so you can have margins!
## Locale sensitive functions
Okay, reading through the vignette further, the str_to_upper, str_to_lower and str_to_title functions do exactly what they say on the tin, but the package documentation is at pains to point out that they will give you different answers depending on where you are, as will sorting functions like str_order and str_sort. Makes perfect sense: alphabets and the ordering of characters within the alphabets vary from place to place, so it’s really nice that these are locale-sensitive. Natural language is messy.
## Pattern matching!
Okay, pattern matching time. My nightmares about grep have mostly settled down in my old age, and it’s refreshing to read something pertaining to regular expressions without bursting into tears! And I really like the way the pattern matching functions are organised in stringr. We have functions that specify tasks.
For the sake of helping my own learning, I’ll type out what they do:
• str_detect finds all strings that match the pattern and returns a logical vector indicating whether they match
• str_subset is similar, but it returns the subset of matching strings
• str_count returns a numeric vector containing the number of times each string matches the pattern
• str_locate returns the positions within the string of the first match, and str_locate_all returns the positions of all matches string
• str_extract returns the matches themselves (first match within a string) and str_extract_all returns all of the matches.
• str_match and str_match_all are similar, but they return the matches split by the groups. (see the vignette for the examples!)
• str_replace and str_replace_all allow you to manipulate the matches, very much the same way that sub and gsub do.
• str_split breaks a string by a separating character; and there’s also the str_split_fixed function that breaks it into a fixed number of chunks.
Okay, a lot of that feels very familiar, and it’ll probably take a bit of getting used to, but I like the overall structure here. I think after a bit of playing it will be really natural.
The thing I really like, though, is the fact that the engine that defines what counts as a pattern is broken up into convenience functions:
• A fixed pattern matches the exact pattern (sequence of bytes)
• A coll pattern is a little more flexible, and recognises that the same character (in human reading terms) can be represented in different ways, which is useful if you’re using non-English characters
• A boundary pattern can match the breaks between words, lines, characters, or sentences. Where by convention "" is treated as meaning boundary("character")
• A regex (the default) is a regular expression
That feels much cleaner than what I’m used to.
## Trying out the pattern matching?
Okay so let’s see if I understand this. Suppose I want to take the start of Pride and Prejudice, as per the ppstart string, and split it up by word, character, or sentence:
str_split(string = ppstart, pattern = boundary("word"))
str_split(string = ppstart, pattern = boundary("character"))
str_split(string = ppstart, pattern = boundary("sentence"))
## [[1]]
## [1] "Pride" "and" "Prejudice" "by"
## [5] "Jane" "Austen" "It" "is"
## [9] "a" "truth" "universally" "acknowledged"
## [13] "that" "a" "single" "man"
## [17] "in" "possession" "of" "a"
## [21] "good" "fortune" "must" "be"
## [25] "in" "want" "of" "a"
## [29] "wife"
##
## [[1]]
## [1] "P" "r" "i" "d" "e" " " "a" "n" "d" " " "P" "r" "e" "j" "u" "d" "i"
## [18] "c" "e" " " "b" "y" " " "J" "a" "n" "e" " " "A" "u" "s" "t" "e" "n"
## [35] "." " " "I" "t" " " "i" "s" " " "a" " " "t" "r" "u" "t" "h" " " "u"
## [52] "n" "i" "v" "e" "r" "s" "a" "l" "l" "y" " " "a" "c" "k" "n" "o" "w"
## [69] "l" "e" "d" "g" "e" "d" "," " " "t" "h" "a" "t" " " "a" " " "s" "i"
## [86] "n" "g" "l" "e" " " "m" "a" "n" " " "i" "n" " " "p" "o" "s" "s" "e"
## [103] "s" "s" "i" "o" "n" " " "o" "f" " " "a" " " "g" "o" "o" "d" " " "f"
## [120] "o" "r" "t" "u" "n" "e" "," " " "m" "u" "s" "t" " " "b" "e" " " "i"
## [137] "n" " " "w" "a" "n" "t" " " "o" "f" " " "a" " " "w" "i" "f" "e" "."
##
## [[1]]
## [1] "Pride and Prejudice by Jane Austen. "
## [2] "It is a truth universally acknowledged, that a single man in possession of a good fortune, must be in want of a wife."
If I wanted to break it up by vowels, I could define a regular expression to do the job:
ppstart %>%
str_split(pattern = regex("[aeiouAEIOU]")) %>%
str_wrap(width = 80) %>%
cat
## Warning in stri_split_lines(str): argument is not an atomic vector;
## coercing
## c("Pr", "d", " ", "nd Pr", "j", "d", "c", " by J", "n", " ", "", "st", "n. ",
## "t ", "s ", " tr", "th ", "n", "v", "rs", "lly ", "ckn", "wl", "dg", "d, th", "t
## ", " s", "ngl", " m", "n ", "n p", "ss", "ss", "", "n ", "f ", " g", "", "d f",
## "rt", "n", ", m", "st b", " ", "n w", "nt ", "f ", " w", "f", ".")
where the calls to str_wrap and cat are there solely to make the output fit on the blog page, and the call to regex is redundant since the stringr package assumes by default that the pattern is a regular expression.
If I wanted to disemvowel Jane Austen, it looks like I can use str_remove as a handy alias for str_replace with replace = "". If I want to get rid of all the vowels rather than just one…
ppstart %>%
str_remove_all(pattern = "[aeiouAEIOU]") %>%
str_squish %>%
str_wrap(width = 80) %>%
cat
## Prd nd Prjdc by Jn stn. t s trth nvrslly cknwldgd, tht sngl mn n pssssn f gd
## frtn, mst b n wnt f wf.
## Playing with Pride and Prejudice
Okay, so now I should be able to do neat things with the whole novel. Let’s start by gluing the pp vector into one long string, since the line breaks don’t seem to appear at any interesting locations
library(glue)
## Warning: package 'glue' was built under R version 3.5.3
pp %<>%
glue_collapse(sep=" ") %>%
str_squish
pp %>%
str_sub(start = 1, end = 500) %>%
str_wrap(width = 80) %>%
cat
## PRIDE AND PREJUDICE By Jane Austen Chapter 1 It is a truth universally
## acknowledged, that a single man in possession of a good fortune, must be in want
## of a wife. However little known the feelings or views of such a man may be on
## his first entering a neighbourhood, this truth is so well fixed in the minds of
## the surrounding families, that he is considered the rightful property of some
## one or other of their daughters. "My dear Mr. Bennet," said his lady to him one
## day, "have you heard that Nether
Okay, so now I want to give myself something to do with this. I’m tired and sick and I can’t think of anything clever, so I’ll just try and locate every appearance of the words "Elizabeth", "Darcy" and "Wickham" in the text:
elizabeth <- str_locate_all(pp, fixed("Elizabeth"))[[1]][,1]
darcy <- str_locate_all(pp, fixed("Darcy"))[[1]][,1]
wickham <- str_locate_all(pp, fixed("Wickham"))[[1]][,1]
And now I will defy all sense (and offend my own sensibilities) by drawing a graph of this using some extraordinarily unsatisfying code:
plot(elizabeth, 1:length(elizabeth), xlab="Position",
ylab="Number of Appearances", xlim=c(0,str_length(pp)), lwd=2,
col="red", type="s")
lines(darcy, 1:length(darcy), col="blue", lwd=2, type="s")
lines(wickham, 1:length(wickham), col="green", lwd=2, type="s")
legend(x = "topleft", legend = c("Elizabeth", "Darcy", "Wickham"),
col = c("red","blue","green"), lwd=2)
No surprises there: Elizabeth occurs most frequently, and at the most uniform rate. At the start of the book Darcy appears just as often, but then there are sections of the book that don’t concern him and the function flatlines for a while. Wickham is absent more often than not.
## Done!
That was surprisingly painless and kind of fun. Of course, it wouldn’t be a string manipulation post without the mandatory XKCD: | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.3998422920703888, "perplexity": 7434.570323650586}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-34/segments/1596439738562.5/warc/CC-MAIN-20200809162458-20200809192458-00351.warc.gz"} |
https://gilkalai.wordpress.com/page/2/ | ## Alef Corner: Math Collaboration
Another artistic view by Alef on mathematical collaboration.
Other Alef’s corner posts
## Alef’s Corner: Math Collaboration 2
Other Alef’s corner posts
## Enjoy!
To cheer you up in difficult times here are songs by Sabine Hossenfelder and by Tom Lehrer. I like the music and lyrics and the unusual combination of science, humor and satire.
Sabine Hossenfelder : Outer space*
Tom Lehrer: That’s mathematics
Sabine Hossenfelder: Theories of everything
Tom Lehrer: Lobachevsky
Sabine Hossenfelder: Schrödinger Cat (The song follows by a physics explanation).
Tom Lehrer: The Professor’s Song (2:55 there is delta for every epsilon)
Sabine Hossenfelder: Ave Maria
Tom Lehrer: The Vatican Rag
Sabine Hossenfelder: Ivory Tower
Tom Lehrer: Elements
Sabine Hossenfelder: Not a Toy
Tom Lehrer The Hunting Song
Sabine Hossenfelder: A Million Miles
Tom Lehrer: Pollution
Sabine Hossenfelder: This is how I pray
Tom Lehrer: Wernher von Braun
Sabine Hossenfelder: Galaxy Song, Monty Python (cover)
Tom Lehrer: Poisoning Pigeons In The Park
Sabine: Catching light
Tom: National brotherhood week
On GLL: Sabine Hossenfelder is featured in this post, and is also mentioned here; Tom Lehrer is featured in this post and this one and is also mentioned here.
Playlists: Tom Lehrer; Sabine Hossenfelder.
Sabine Hossenfelder (left) Tom Lehrer (right)
*”Outer space” is a famous mathematical concept as well.
## Noam D. Elkies piano improvisations
Every day since March 27, 2020 Noam Elkies (Noam’s home page) uploaded a new piece of piano improvisation. The Hebrew title of his page is “Music will let you forget the plague”.
Here is the very first comforting piece a la Schumann/Chopin; a piece based on the the Marseillaise; Bim Bam Bom (a popular Israeli song), and a tango. And yesterday, Yesterday!
## To cheer you up even further: Problem chess with Noam Elkies
And excerpt from a forthcoming book on Chess and Mathematics by Noam Elkies and Richard Stanley: 12 page PDF file. A paper by Noam Elkies and Richard Stanley: The mathematical knight: PDF document.
## Quantum Matters
A comparison between the Google estimator U for the fidelity and two improved estimators that we studied MLE (maximum likelihood estimator) and V (a variant of U). (More figures at the end of the post.)
Here are some links on quantum matters. I hope to return to them in more detail in some future posts.
## 1. A paper with Yosi Rinott and Tomer Shoham on the Statistics of Google’s experiment
Yosef Rinott, Tomer Shoham and Gil Kalai: Statistical aspects of the quantum supremacy demonstration, (arXive)
Abstract:
The notable claim of quantum supremacy presented by Google’s team in 2019 consists of demonstrating the ability of a quantum circuit to generate, albeit with considerable noise, bitstrings from a distribution that is considered hard to simulate on classical computers. Verifying that the generated data is indeed from the claimed distribution and assessing the circuit’s noise level and its fidelity is a purely statistical undertaking.
The objective of this paper is to explain the relations between quantum computing and some of the statistical aspects involved in demonstrating quantum supremacy in terms that are accessible to statisticians, computer scientists, and mathematicians.
Starting with the statistical analysis in Google’s demonstration, which we explain, we study various estimators of the fidelity, and different approaches to testing the distributions generated by the quantum computer. We propose different noise models, and discuss their implications. A preliminary study of the Google data, focusing mostly on circuits of 12 and 14 qubits is discussed throughout the paper.
I am greatly enjoying working with Yosi and Tomer, and I hope to devote a special post to the very interesting statistics of the Google supremacy experiment.
## 2. My paper The Argument against Quantum Computers, the Quantum Laws of Nature, and Google’s Supremacy Claims
Here is how the paper concludes
Over the past four decades, the very idea of quantum computation has led to many advances in several areas of physics, engineering, computer science, and mathematics. I expect that the most important application will eventually be the understanding of the impossibility of quantum error-correction and quantum computation. Overall, the debate over quantum computing is a fascinating one, and I can see a clear silver lining: major advances in human ability to simulate quantum physics and quantum chemistry are expected to emerge if quantum computational supremacy can be demonstrated and quantum computers can be built, but also if quantum computational supremacy cannot be demonstrated and quantum computers cannot be built.
Some of the insights and methods characteristic of the area of quantum computation might be useful for classical computation of realistic quantum systems – which is, apparently, what nature does.
The link above is the most recent version that will be updated; Here is the arXive version. A discussion on Hacker News.
## 3. My Dec 2019 surprise lecture and the panel discussion
My Dec 19 2019 (B.C.) surprise lecture at the mathematics of quantum computing school and the afternoon panel on the same day. It turned out that the lecture was videotaped. The slides can be seen in this post. Remarkably, social distancing was pioneered by the session chair toward the end of the lecture (while not justified in that case).
Here once again again is the link for the panel discussion on quantum supremacy of the same day (reviewed here) . Here is a quote of mine from the panel.
Of course, it is important to think what are the implications of quantum supremacy, is it useful? what does it say on the extended Church-Turing thesis? on prospects for quantum error-correction and universal quantum computers? etc. but I think that in the next few years one thing that we need to also concentrate on is the following question: Is the Google experiment correct? Is this a correct scientific verification of quantum supremacy?
## 4. My July 15 USTLC lecture
Four slides from my USTLC zoom lecture. (Click to enlarge.)
Here is the videotaped Zoom presentation and here are the slides.
## 5. A small taste of quantum poetry for the skeptics. (A full post is coming.)
Poems by Peter Shor and Renan Gross (click to enlarge)
Peter Shor pioneered quantum poetry for the skeptics over Twitter. There were many very nice contributions all over social media by Renan Gross, John Dowling, Vidit Nanda, ⟨dl|yonge|mallo⟩, Alfred Marcel Bruckstein, Kenneth Regan, and others. Keep the quantum poems coming! Of course, the poems should be taken with humor. Here is a small taste.
### Jon Dowling
Posted in Quantum, Statistics | Tagged , | 5 Comments
## Pokrovskiy’s startling morning rainbow
Rota’s Basis Conjecture holds asymptotically, by Alexey Pokrovskiy
Abstract: Rota’s Basis Conjecture is a well known problem from matroid theory, that states that for any collection of n bases in a rank n matroid, it is possible to decompose all the elements into n disjoint rainbow bases. Here an asymptotic version of this is proved. We show that it is possible to find n − o(n) disjoint rainbow independent sets of size n − o(n).
A rainbow basis is a basis with one element from each collection.
(I thank Nati Linial for telling me about it.)
Another way to formulate Rota’s basis conjecture (for representable matroids) is that if B1B2, …, Bn are n bases of an n-dimensional vector space V (not necessarily distinct or disjoint), then there exists an n × n grid of vectors (vij) such that
1. the n vectors in row i are the members of the ith basis Bi (in some order), and
2. in each column of the matrix, the n vectors in that column form a basis of V.
If all the bases are the standard basis then this reduces to the existence of Latin squares.
Unrelated trivia question: AGC-GTC-TGC-GTC-TGC-GAC-GATC-? what comes next in the sequence?
We mentioned Rota’s basis conjecture in various earlier posts. A classic paper on the subject is the 1989 paper by Rosa Huang and Gian Carlo-Rota. Three and a half years ago Timothy Chow lunched a polymath project (Polymath 12) to solve it. (Here is my post on the project with various variants of the conjecture, the first post on the polymath blog, and the wiki). See this post for several famous conjectures by Rota, and this post about the related Alon-Tarsi conjecture.
## To Cheer you up in Difficult Times 8: Nathan Keller and Ohad Klein Proved Tomaszewski’s Conjecture on Randomly Signed Sums
Today we talk about the paper, Proof of Tomaszewski’s Conjecture on Randomly Signed Sums, by Nathan Keller and Ohad Klein.
Consider a unit vector $a=(a_1,a_2,\dots, a_n).$ That is $\sum_{i=1}^n a_i^2=1$. Consider all ($2^n$) signed sums $\displaystyle \epsilon_1a_1+\epsilon_2a_2+\cdots +\epsilon_n a_n,$ where each $\epsilon_k$ is either 1 or -1.
Theorem (Keller and Klein (2020) asked by Boguslav Tomaszewski (1986)): For at least $2^{n-1}$ signed sums $\displaystyle |\epsilon_1a_1+\epsilon_2a_2+\cdots +\epsilon_n a_n| \le 1 .$
Another way to state the theorem is that the probability of a signed sum to be in the interval [-1, 1] is at least 1/2.
To see that this is best possible consider the case that $n=2$ and let $a_1,a_2$ be non zero. For the sum in question to exceed one we need both summands to have the same sign which happens half of the times. There is another example of importance, the vector $(\frac{1}{2}, \frac{1}{2}, \frac {1}{2}, \frac{1}{2})$. Here 3/8 of the absolute values of signed sums (6 out of 16) are below 1 (in fact, equal to zero), 1/2 equal to 1 and 1/8 exceed 1. Holzman and Kleitman proved in 1992 that the fraction of absolute values of signed sums below 1 is always at least 3/8.
Congratulations to Nathan and Ohad. I will say a little more about the problem below but before that, a few more things.
### A few more things
Luca Trevisan posted on his blog In Theory a post “Silver linings” about two cheerful pieces of news. The first one is “Karlin, Klein, and Oveis Gharan have just posted a paper in which, at long last, they improve over the 1.5 approximation ratio for metric TSP which was achieved, in 1974, by Christofides.”
The second one is about breaking the logarithmic barrier for Roth’s theorem that we wrote about here. This was also discussed by Bill Gasarch on Computational Complexity. In the comment section of my post there is an interesting discussion regarding timetable for future achievements and how surprising they would be.
The third is about Ron Graham, a friend and a mathematical giant who passed away a few days ago. Here is a moving post by Fan Chung, a web page for Ron set by Fan, and a blog post by Dick and Ken on GLL.
The fourth is that there is a nice collection of open problems on Boolean functions that is cited in the paper of Nathan and Ohad: Y. Filmus, H. Hatami, S. Heilman, E. Mossel, R. O’Donnell, S. Sachdeva, A. Wan, and K. Wimmer, Real analysis in computer science: A collection of open problems.
The fifth is that both our (HUJI) combinatorics seminar and basic notions seminar are running and are recorded. Here are the links. (Hmm, the links are not yet available, I will update.)
## Back to the result of Keller and Klein
Daniel Kleitman and Ron Holzman
### A quick orientation
If the $a_i$s are all the same, or small, or random, then to compute the probability that the weighted sum is between -1 and 1, we can use some Gaussian approximation and then we will find ourselves in a clash of constants that goes our way. The probability will be close to a constant well above 1/2. So what we need to understand is the case where some $a_i$s are large.
### Early papers on the problem
The problem first appeared in the American Math Monthly. Richard Guy collected several problems and challenged the readers Any Answers Anent These Analytical Enigmas? (I don’t know what the fate of the other questions is.) Holzman and Kleitman proved in 1992 that the fraction of absolute values of signed sums below 1 is always at least 3/8, and this is tight. For many years, 3/8 was the record for the original problem, until the 2017 paper by Ravi Boppana and Ron Holzman: Tomaszewski’s problem on randomly signed sums: Breaking the 3/8 barrier, where a lower bound of 0.406, was proved. The current record 0f 0.46 was proved in the paper Improved Bound for Tomaszewski’s Problem by Vojtěch Dvořák, Peter van Hintum, and Marius Tiba. The new definite result by Nathan and Ohad used some ideas of these early papers.
### What is the crux of matters
Let me quote what the authors kindly wrote me:
“The crux of the matter is how to deal with the case of very large coefficients ($a_1+a_2>1$). We gave a short semi-inductive argument covering this case (this is Section 5 of the paper). The argument is only semi-inductive, as it requires the full assertion of Tomaszewski for any n'<n, and gives only the case ($a_1+a_2>1$) for $n$. But this means that if we can handle all other cases by other methods then we will be done.
The semi-inductive argument takes only 3 pages. Handling the other cases takes 72 more pages and requires several new tools, but is closer to things that were done in previous works. (Actually, after we found the 3-page argument, we were quite sure we will be able to finalize the proof; this indeed happened, but took a year).”
Most of the paper deals with the case of small coefficients. This requires several ideas and new tools.
### Rademacher sums: Improved Berry-Esseen and local tail inequalities
If all coefficients are “sufficiently small”, then we can
approximate X by a Gaussian and the inequality should follow. However, using the standard Berry-Esseen bound, this holds only if all coefficients are less than 0.16.
Nathan and Ohad showed that for Rademacher sums, namely random variables of the form $X=\sum a_i x_i$, as discussed in the conjecture, a stronger Berry-Esseen
bound can be obtained, and this bound shows immediately that Tomaszewski’s assertion holds whenever all coefficients are less than 0.31. The stronger bound stems
from a method of Prawitz, presented in the 1972 paper. H. Prawitz, Limits for a distribution, if the characteristic function is given in a finite domain, which appeared in the Scandinavian Actuarial journal.
The second tool is local tail inequalities for Rademacher sums, of the form $\Pr[a where a,b,c,d satisfy certain conditions. Inequalities of this kind were obtained before by Devroye and Lugosi in the 2008 paper: Local tail bounds for functions of independent random variables.
These local tail inequalities already have some other applications, e.g., to analysis of Boolean functions. They were developed and applied in an earlier paper paper of Keller and Klein: Biased halfspaces, noise sensitivity, and relative Chernoff inequalities. Let me mention my related MO question A variance tail description for continuous probability distributions.
### A couple more ingredients
A stopping time argument. Variants of Tomaszewski’s problem appeared in various fields. The problem was stated independently in a 2002 paper by Ben-Tal, Nemirovski, Roos, Robust solutions of uncertain quadratic and conic-quadratic problems. A stopping time argument introduced there (for proving a lower bound of 1/3) played a crucial role in subsequent works and the critical semi-inductive argument by Nathan and Ohad.
Refinements of the famous Chebyshev’s inequality. (Did you know Chebyshev’s full name? Ans: Pafnuty Lvovich Chebyshev.)
### Questions and connections that come to mind
Q1: What can be said about families $\cal F$ of signs that can serve as those signs for which $|\epsilon_1a_1+\epsilon_2a_2+\cdots +\epsilon_n a_n| \le 1 ,$ for some vector $a$.
Q2: What can be said about the complex version or even more generally about high dimensions?
Q3: Are there any relations to Littlewood-Offord type problems?
Q4: Is there any relation to the Komlos Conjecture?
See also this MO question by Luca Trevisan and this one by George Lowther.
### Is there a simpler proof?
We can ask about simpler or just different proofs for almost every result we discuss here. But here the statement is so simple…
Posted in Analysis, Combinatorics, Probability | | 11 Comments
## Noam Lifshitz: A new hypercontractivity inequality — The proof!
This is a guest post kindly contributed by Noam Lifshitz. Here is a pdf version. This post is a continuation of the post To cheer you up in difficult times 3: A guest post by Noam Lifshitz on the new hypercontractivity inequality of Peter Keevash, Noam Lifshitz, Eoin Long and Dor Minzer, and it gives the proof of the new hypercontractive inequality. We plan a third post where various applications will be mentioned.
Before we get to the post I want to mention that there are a lot of activities on the web. I may devote a special post to links and discussion (and contributing links in the comment section is very welcome.) but meanwhile a few links: 1) Advances in Boolean Function Analysis Lecture Series (thanks to Avishay Tal and Prasad Raghavendra for letting me know); 2) Online course in Foundations of Algebraic Geometry Given by Ravi Vakil from Stanford. You can take the course at varying levels of involvement. (Thanks to Tami Ziegler for telling me) A very very interesting way of online teaching. 3) A site with online mathematical lectures.
Aline Bonami with Szilard Revesz and me (2006). Aline Bonami first proved the 2-point hypercontractive inequality which is very useful in the analysis of Boolean functions. (Leonard Gross proved it independently a few years later and William Beckner found important applications to harmonic analysis.)
## Proof of the new hypercontractivity inequality
Our aim is to prove the hypercontractivity theorem for global functions. The proof here is taken from a joint paper with David Ellis and Guy Kindler that’ll soon be out on the Arxiv.
### Theorem 1:
$\displaystyle \|\mathrm{T}_{1/100}f\|_{4}^{4}\le\sum_{S\subseteq\left[n\right]}\mathbb{E}_{x\in\left\{ 1,\ldots,m\right\} ^{S}}\|L_{S}[f]_{S\rightarrow x}\|_{2}^{4},$
Here we use the notations given in the last blog post. Let us first get a feel for our hypercontractivity theorem by proving the ${n=1}$ case. Here the RHS is ${\|f\|_{2}^{4}+\|f-\mathbb{E}\left[f\right]\|_{4}^{4}.}$
### 1. Proof of the ${n=1}$ case
We will prove the following slightly stronger version of Theorem 1 for the ${n=1}$ case.
Proposition 2:
Let ${f\colon\left\{ 1,\ldots,m\right\} \rightarrow\mathbb{C}.}$ Let ${\rho\le\frac{1}{10}.}$ Then
$\displaystyle \|\mathrm{T}_{\rho}f\|_{4}^{4}\le\|f\|_{2}^{4}+\|f-\mathbb{E}\left[f\right]\|_{4}^{4}.$
Proof: Let us write ${L\left[f\right]}$ for ${L_{1}\left[f\right]=f-\mathbb{E}\left[f\right].}$ Rearranging, we have
$\displaystyle f=\mathbb{E}\left[f\right]+L\left[f\right].$
The noise operator in the ${n=1}$ case is by definition equal to ${\rho Id+\left(1-\rho\right)\mathbb{E},}$ where ${\mathbb{E}}$ is the expectation over ${\text{\ensuremath{\left\{ 1,\ldots,m\right\} }}}$ operator, and ${Id}$ is the identity operator. Hence,
$\displaystyle \mathrm{T}_{\rho}f=\mathbb{E}\left[f\right]+\rho L[f].$
Now when expanding the 4-norm of the function ${\|\mathrm{T}_{1/100}f\|_{4}^{4}}$, we obtain
$\displaystyle \|\mathrm{T}_{\rho}f\|_{4}^{4} \le\left|\mathbb{E}\left[f\right]\right|^{4}$
$\displaystyle +6\rho^{2}\left|\mathbb{E}\left[f\right]\right|^{2}\|Lf\|_{2}^{2}+$
$\displaystyle +4\rho^{3}\left|\mathbb{E}\left[f\right]\right|\|L\left[f\right]\|_{3}^{3}+$
$\displaystyle + \rho^{4}\|L\left[f\right]\|_{4}^{4},$
where we used the fact that the expectation of ${L\left[f\right]}$ is 0. When looking at the right hand side of the global hypercontractivity theorem, we see most of the above terms except for the one involving the third norm of the Laplacian. Indeed we have
$\displaystyle RHS =\|f\|_{2}^{4}+\|L\left[f\right]\|_{4}^{4}$
$\displaystyle =\left|\mathbb{E}\left[f\right]\right|^{4}$
$\displaystyle +2\|L\left[f\right]\|_{2}^{2}\left|\mathbb{E}\left[f\right]\right|^{2}$
$\displaystyle +\|L\left[f\right]\|_{2}^{4}$
$\displaystyle +\|L\text{\ensuremath{\left[f\right]\|}}_{4}^{4}.$
Hence we see that the only term in the left hand side that doesn’t appear with a greater coefficient in the left hand side is the term ${\left|\mathbb{E}\left[f\right]\right|\|L\left[f\right]\|_{3}^{3},}$ and by AM-GM we have
$\displaystyle \left|\mathbb{E}\left[f\right]\right|\|L\left[f\right]\|_{3}^{3}$ $\displaystyle =\mathbb{E}\left[\left|\mathbb{E}\left[f\right]\right|\left|L\left[f\right]\right|^{3}\right]$
$\displaystyle \le\mathbb{E}\left[\frac{\left|\mathbb{E}\left[f\right]\right|^{2}\left|L\left[f\right]\right|^{2}+\left|L\text{\ensuremath{\left[f\right]}}\right|^{4}}{2}\right]$
$\displaystyle =\frac{1}{2}\left|\mathbb{E}\left[f\right]\right|^{2}\|L\left[f\right]\|_{2}^{2}+\frac{1}{2}\|L\left[f\right]\|_{4}^{4},$
which allows us to upper bound the only term appearing in the left hand side but not in the right hand side by corresponding terms that do appear in the right hand side. $\Box$
### 2. Tensorisation lemma
Next we are going to prove a theorem that doesn’t seem to fit to our setting, but we’re going to fit it in by force. Let ${X,Y}$ be finite sets. Let us write ${\mathcal{F}\left(X\right)}$ for the linear space of complex valued functions on ${X}$. The space ${\mathcal{F}\left(X\times Y\right)}$ can be identified with the space ${\mathcal{F}\left(X\right)\otimes\mathcal{F}\left(Y\right),}$ where a pair of function ${f\otimes g}$ is identified with the function
$\displaystyle \left(x,y\right)\mapsto f\left(x\right)g\left(y\right)$
in ${\mathcal{F}\left(X\times Y\right).}$
Given two operators ${A_{1}\colon\mathcal{F}\left(X_{1}\right)\rightarrow\mathcal{F}\left(Y_{1}\right),A_{2}\colon\mathcal{F}\left(X_{2}\right)\rightarrow\mathcal{F}\left(Y_{2}\right)}$, the operator ${A_{1}\otimes A_{2}\colon\mathcal{F}\left(X_{1}\times X_{2}\right)\rightarrow\mathcal{F}\left(Y_{1}\times Y_{2}\right)}$ is the unique operator sending ${f\otimes g}$ to ${A_{1}f\otimes A_{2}g}$. We write ${A^{\otimes n}}$ for ${A\otimes\cdots\otimes A.}$ The operator ${A_{1}\otimes A_{2}}$ can also be defined more explictly in terms of its values on functions. The operator ${A_{1}\otimes A_{2}}$ can be understood more explicitly by noting that it is the composition of the operators ${A_{1}\otimes I}$ and ${I\otimes A_{2}.}$ Now the operator ${A\otimes I}$ is given by ${A\otimes If\left(x,y\right)=Af_{y}\left(x\right),}$ where ${f_{y}\left(x\right)=f\left(x,y\right).}$
Lemma 3: Let ${X,Y,Z}$ be measure spaces with finite underlying sets. Let ${A\colon\mathcal{F}\left(X\right)\rightarrow\mathcal{F}\left(Y\right),B\colon\mathcal{F}\left(X\right)\rightarrow\mathcal{F}\left(Z\right)}$ be operators satisfying
$\displaystyle \|Af\|_{4}\le\|Bf\|_{4}$
for all functions ${f\in\mathcal{F}\left(X\right).}$
Then
$\displaystyle \|A^{\otimes n}f\|_{4}\le\|B^{\otimes n}f\|_{4}$
for all ${f\in\mathcal{F}\left(X^{n}\right).}$
Here the spaces ${X^{n},Y^{n},}$ and ${Z^{n}}$ are equipped with the product measure, where the measure of an atom is the product of the measures of its coordiates.
Proof: For each ${y\in X,}$ let ${g_{y}}$ be given by ${g_{y}:=A^{\otimes\left(n-1\right)}f\left(\cdot,y\right).}$ As mentioned ${A^{\otimes n}f\left(x,y\right)=Ag_{y}\left(x\right).}$ Hence by hypothesis, we have
$\displaystyle \mathbb{E}\left[\left|\mathrm{A}^{\otimes n}f\right|^{4}\right]$ $\displaystyle =\mathbb{E}_{y}\mathbb{E}_{x}\left|Ag_{y}\left(x\right)\right|^{4}$
$\displaystyle \le\mathbb{E}_{y}\mathbb{E}_{x}\left|Bg_{y}\left(x\right)\right|^{4}$
$\displaystyle =\|A^{\otimes n-1}\otimes B\|_{4}^{4}.$ We may now repeat the same process on each of the other coordinates to replace the ${A}$s by ${B}$s one by one. $\Box$
### 3. The main idea: Fourifying the 2-norms.
The strategy of our proof is to take the theorem
$\displaystyle \|\mathrm{T}_{\rho}f\|_{4}\le\|f\|_{2}^{4}+\|f-\mathbb{E}\left[f\right]\|_{4}^{4},$
which we established in the ${n=1}$ case for ${\rho\le\frac{1}{10}}$, and to turn it into an essentially equivalent statement about 4-norms. We will then get a tensorised statement for general ${n}$, which we will be able to convert back into our hypercontractivity theorem for global functions. Our idea is to encode our function ${f}$ as a function ${\mathrm{En}\left(f\right)\colon\left\{ -1,1\right\} ^{n\left(p-1\right)}\rightarrow\mathbb{R}}$ satisfying
$\displaystyle \mathrm{En}\circ T_{\rho}=\mathrm{T}_{\rho}\circ\mathrm{En}$
and
$\displaystyle \|\mathrm{En}f\|_{2}=\|f\|_{2}.$
The benefit of working with ${\mathrm{En}f}$ rather than ${f}$ is that in ${\left\{ 0,1\right\} ^{n\left(p-1\right)}}$ one may move between 4-norms and 2-norms by appealing to the hypercontractivity theorem there, which gives
$\displaystyle \|\mathrm{T}_{\frac{1}{\sqrt{3}}}\circ\mathrm{En}f\|_{4}\le\|\mathrm{E}nf\|_{2}\le\|\mathrm{En}f\|_{4}$
at the cost of some noise.
To define ${\mathrm{En}}$ we use Fourier analysis of Abelian groups. Let us briefly recall it. For simplicity let us assume that ${f\colon\left(\mathbb{Z}/p\mathbb{Z}\right)^{n}\rightarrow\mathbb{C},}$ where ${p}$ is a prime. Let ${\omega}$ be a ${p}$th root of unity. For any ${\gamma\in\left(\mathbb{Z}/p\mathbb{Z}\right)^{n}}$ we have a character ${\chi_{\gamma}\colon\left(\mathbb{Z}/p\mathbb{Z}\right)^{n}\rightarrow\mathbb{C}}$ given by ${\chi_{\gamma}\left(x\right)=\omega^{\left\langle \gamma,x\right\rangle }.}$ The ${\chi_{\gamma}}$ are an orthonormal basis of ${\left(\mathbb{Z}/p\right)^{n}}$ and we write ${f=\sum\hat{f}\left(\gamma\right)\chi_{\gamma}}$, where ${\hat{f}\left(\gamma\right)=\left\langle f,\chi_{\gamma}\right\rangle .}$ Note that ${\chi_{0}}$ is the constant function, and so we have
$\displaystyle \hat{f}\left(0\right)=\left\langle f,\chi_{0}\right\rangle =\mathbb{E}\left[f\right],$
which gives
$\displaystyle f=\mathbb{E}\left[f\right]+\sum\hat{f}\left(i\right)\chi_{i}.$
Our mission will first be to convert the ${2}$-norm of a function ${f\colon\mathbb{Z}/p\rightarrow\mathbb{R}}$ to the ${4-}$norm of a different function.
We define an encoding operator ${\mathrm{En}\colon\mathbb{Z}/p\mathbb{Z}\rightarrow\left\{ -1,1\right\} ^{p-1}}$ by setting
$\displaystyle f\mapsto\mathbb{E}\left[f\right]+\sum_{i\in\left\{ 1,\ldots,p-1\right\} }\hat{f}\left(i\right)x_{i}.$
We have
$\displaystyle \|f\|_{2}^{2}=\|\mathrm{En}f\|_{2}^{2},$
as the ${\chi_{i}}$ are orthonormal and so are the ${x_{i}.}$ Moreover, ${\mathrm{T}_{\rho}\circ\mathrm{En}=\mathrm{En}\circ T_{\rho}}$ by the Fourier formula for ${\mathrm{T}_{\rho}.}$ Since ${2}$-norms are always smaller than 4-norms on probability spaces, we’ve got the following corollary of Proposition 2.
Lemma 4. For all ${\rho\le\frac{1}{10}}$ and all ${f\colon\mathbb{Z}/p\mathbb{Z}\rightarrow\mathbb{C}}$ we have
$\displaystyle \|\mathrm{T}_{\rho}f\|_{4}^{4}\le\|\mathrm{En}\left(f\right)\|_{4}^{4}+\|f-\mathbb{E}\left[f\right]\|_{4}^{4}.$
We now reach the final little trick. We define a measure space ${Y}$ whose underlying set is ${\mathbb{Z}/p\mathbb{Z}\sqcup\left\{ 0,1\right\} ^{\left\{ p-1\right\} },}$ and where the measure is given by ${\mu\left(i\right)=\frac{1}{p}}$ for ${i\in\mathbb{Z}/p\mathbb{Z}}$ and ${\mu\left(x\right)=\frac{1}{2}^{p-1}}$ for ${x\in\left\{ -1,1\right\} ^{p-1}.}$ We let ${B\colon\mathcal{F}\left(X\right)\rightarrow\mathcal{F}\left(Y\right)}$ be given by ${Bf=\mathrm{En}f}$ on ${\left\{ -1,1\right\} ^{p-1}}$ and letting it be ${f-\mathbb{E}\left[f\right]}$ on ${\mathbb{Z}/p\mathbb{Z}.}$ This way Lemma 4 takes the form ${\|\mathrm{T}_{\rho}f\|_{4}\le\|Bf\|_{4}.}$
### 4. Tensorised operators
The operator ${\mathrm{T}_{\rho}}$ on ${\mathbb{Z}/p\mathbb{Z}^{n}}$ satisfies ${\mathrm{T}_{\rho}=\mathrm{T}_{\rho}^{\otimes n},}$ where the latter ${\mathrm{T}_{\rho}}$ refers to the noise operator on ${\mathbb{Z}/p.}$ The characters ${\chi_{\gamma}}$ satisfy ${\chi_{\gamma}=\bigotimes\chi_{\gamma_{i}},}$ and so we have the Fourier formula
$\displaystyle \mathrm{T}_{\rho}f =\sum_{\gamma}\rho^{\#\left\{ i:\gamma_{i}\ne0\right\} }\hat{f}\left(\gamma\right)\chi_{\gamma}.$
We also have
$\displaystyle L_{S}\left[f\right]=\bigotimes_{i\in S}\left(f\mapsto f-\mathbb{E}\left[f\right]\right)\otimes\bigotimes_{i\notin S}Id,$
and so
$\displaystyle L_{S}\left[f\right]=\sum_{\gamma:\gamma_{i}\ne0\text{ for all }i\in S}\hat{f}\left(\gamma\right)\chi_{\gamma}.$
This will allow us to conclude that
$\displaystyle L_{S}\left[\mathrm{T}_{\rho}f\right]_{S\rightarrow x}=\rho^{\left|S\right|}T_{\rho}L_{S}[f]_{S\rightarrow x}.$
We will also encounter the operator ${\mathrm{En}^{\otimes n},}$ which by abusing notation we also call ${\mathrm{En}}$ encodes
$\displaystyle f=\sum_{\gamma}\hat{f}\left(\gamma\right)\chi_{\gamma}$
as the function ${\sum_{\gamma}\widehat{f}\left(\gamma\right)\prod_{i=1}^{n}x_{pi+\gamma_{i}}}$ on ${\left\{ -1,1\right\} ^{n\left(p-1\right)}.}$
Now finally we can get to the understanding of the operator ${B^{\otimes n}.}$ The space ${Y^{n}}$ is the disjoint union of ${2^{n}}$ spaces of the form
$\displaystyle \left(\mathbb{Z}/p\mathbb{Z}\right)^{S}\times\left(\left\{ -1,1\right\} ^{p-1}\right)^{\left[n\right]\setminus S}.$
By definition of the tensor product, for ${x,y\in\left(\mathbb{Z}/p\mathbb{Z}\right)^{S}\times\left(\left\{ -1,1\right\} ^{p-1}\right)^{\left[n\right]\setminus S}}$ is the function
$\displaystyle B^{n}f\left(x,y\right)=\mathrm{En}\left(L_{S}[f]_{S\rightarrow x}\right)\left(y\right).$
### 5. Finishing the proof
Proof: Lemmas 3 and 4 yield:
$\displaystyle \|\mathrm{T}_{\rho}f\|_{4}^{4} \le\|B^{\otimes n}f\|_{4}^{4}$ $\displaystyle =\sum_{S\subseteq\left[n\right]}\mathbb{E}_{x\sim\mathbb{Z}/p\mathbb{Z}^{S}}\|\mathrm{En}\left(L_{S}[f]_{S\rightarrow x}\right)\|_{4}^{4},$
for any ${\rho\le\frac{1}{10}.}$ We now have
$\displaystyle \|\mathrm{T}_{\frac{\rho}{\sqrt{3}}}f\|_{4}^{4}$ $\displaystyle =\sum_{S\subseteq\left[n\right]}(\frac{1}{\sqrt{3}})^{\left|S\right|}\mathbb{E}_{x\sim\mathbb{Z}/p\mathbb{Z}^{S}}\|\mathrm{T}_{\frac{1}{\sqrt{3}}}\left(\mathrm{En}\left(L_{S}[f]_{S\rightarrow x}\right)\right)\|_{4}^{4},$
$\displaystyle \le\sum_{S\subseteq\left[n\right]}\mathbb{E}_{x\sim\mathbb{Z}/p\mathbb{Z}^{S}}\|\mathrm{En}\left(L_{S}[f]_{S\rightarrow x}\right)\|_{2}^{4}$
$\displaystyle =\sum_{S\subseteq\left[n\right]}\mathbb{E}_{x\sim\mathbb{Z}/p\mathbb{Z}^{S}}\|L_{S}[f]_{S\rightarrow x}\|_{2}^{4}.$
The first equality follows from the formula ${L_{S}\left[\mathrm{T}_{\rho}f\right]_{S\rightarrow x}=\rho^{\left|S\right|}\mathrm{T}_{\rho}L_{S}\left[f\right]_{S\rightarrow x}}$ and the fact that ${\mathrm{T_{\rho}}}$ commutes with the encoding. The inequality used hypercontractivity on the discrete cube. The last equality follows from the fact that the ${\mathrm{En}}$ operator preserves 2-norms. $\Box$
## To cheer you up in difficult times 7: Bloom and Sisask just broke the logarithm barrier for Roth’s theorem!
### Thomas Bloom and Olof Sisask: Breaking the logarithmic barrier in Roth’s theorem on arithmetic progressions, arXiv:200703528
Once again Extraordinary news regarding Roth Theorem! (I thank Ryan Alweiss for telling me about it and Rahul Santhanam for telling me about Thomas and Olof’s earlier attempts.)
Suppose that $R_n$ is a subset of $\{1,2,\dots, n \}$ of maximum cardinality not containing an arithmetic progression of length 3. Let $r_3(n)=|R_n|$. Roth proved that $r_3(n)=o(n)$.
A few days ago Thomas Bloom and Olof Sisask proved that for some $c>0$
$r_3(n) \le \frac {n}{\log^{1+c} n}$
This is an extraordinary result!!! I will tell you a little more about it below.
## Ron Graham
I just heard yesterday the sad news that Ron Graham passed away. Ron was an extraordinary mathematician and an extraordinary person. I first met Ron in Montreal in 1978 and we met many times since then. Ron will be dearly missed.
### Back to the new bounds on Roth’s theorem
From an abstract of a lecture by Thomas and Olof: “This is the integer analogue of a result of Bateman and Katz for the model setting of vector spaces over a finite field, and the proof follows a similar structure.”
A catchy (weaker) formulation which goes back to Erdos and Turan is:
Let $a_n$ be a sequence of integers so that $\sum \frac{1}{a_n} = \infty$, then the sequence contains an arithmetic progression of length three!!
Bloom and Sisask’s result implies, of course, Van der Korput’s result that the primes contain infinitely many 3-terms arithmetic progression as well as Green’s 2005 result asserting it for every dense subset of primes.
Szemeredi’s celabrated result extended Roth’s theorem to arithmetic progression of any fixed size, and Green-Tao celebrated 2008 result asserts that the primes (or a dense subsets of primes) contain arithmetic progression of any length. (The case of 3-term AP is so far much simpler for all the results mentioned below.)
A little more about the history of the problem below the fold
## To cheer you up in difficult times 6: Play Rani Sharim’s two-player games of life, read Maya Bar-Hillel presentation on catching lies with statistics, and more.
Sorry for the long blog silence. In this post I wish to give a few links each of which probably deserves a full post. I will start with
## Rani Sharim’s two-player variants of John Conway’s game-of-life
Here is a web-page by a student in my “Game Theory” course where you can play several two-players variants of John Conway’s game-of-life. (A couple of variants were considered before. See, e.g. this paper.)
I really enjoyed playing Rani’s games and it can certainly cheer you up in difficult times. Questions about the game, remarks, and suggestions for improvements and for new features, are most welcome.
## How to catch lies with statistics, a 2006 presentation by Maya Bar-Hillel
Maya Bar-Hillel (left) and Ester Samuel-Cahn
Here is an interesting 2006 power point presentation entitled How to detect lies with statistics by Maya Bar-Hillel. This was a talk given by Maya at the conference honoring Prof. Ester Samuel- Cahn , Jerusalem, December 18-20, 2006, and it described a planned research project of Maya Bar-Hillel with Yossi Rinott, David Budescu and myself. At the end we did not pursue it, mainly because each of us was involved in various other projects (but also because we were skeptical about some aspects of it.) Ester Samuel-Cahn (1933-2015) was a famous Israeli statistician. (Here is a post by Yosi Levy in Hebrew about the conference and about Ester.)
The lecture starts with “Last year, Statistical Science celebrated 50 years for `How to Lie with Statistics’ the book [by Durell Huff] whose title inspired this talk.”
And here are a few other quotes from Maya’s presentation
“We are not sure a general toolkit for detecting lies with statistics can be developed. Perhaps that explains why none yet exists. We have shown just a collection of anecdotes. But they can be classified and categorized. Some do seem generalizeable, at least to some extent.”
and the conclusion
A famous quip by Fred Mosteller: “It is easy to lie with statistics, but easier to lie without them.”
Likewise, we should say: “It is possible to detect (some) lies with statistics, but easier to detect them with other means”.
## New bounds for Ryser’s conjecture and related problems
Peter Keevash, Alexey Pokrovskiy, Benny Sudakov, and Liana Yepremyan’s paper New bounds for Ryser’s conjecture and related problems, describes remarkable progress very old questions regarding transversals in Latin square.
## Topological Tverberg news
I came across a very interesting paper The topological Tverberg problem beyond prime powers by Florian Frick and Pablo Soberón with new bounds and a new method for topological Tverberg theorem in the non prime-power case.
## Jeager’s conjecture refuted
A year ago I came across this cool facebook post by Rupei Xu
OMG! Just learned that Jaeger’s conjecture is false for every t>=3. An interesting consequence of it is that a specific version of Goddyn’s conjecture on thin spanning trees is false, which shows some negative evidence that the thin spanning tree approaches may fail to lead to a constant factor approximation algorithm for ATSP!
## More on the game of life
Let me mention two problems I posted 6-7 years ago about Conway’s game of life. Conway’s game of life for random initial position and Does a noisy version of Conway’s game of life support universal computation?
Posted in Combinatorics, Games, Rationality | Tagged , | 1 Comment | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 188, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7739387154579163, "perplexity": 2705.0157222857565}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-50/segments/1606141184870.26/warc/CC-MAIN-20201125213038-20201126003038-00192.warc.gz"} |
https://proofwiki.org/wiki/Definition:Order_of_Group_Element | # Definition:Order of Group Element
## Definition
Let $G$ be a group whose identity is $e_G$.
Let $x \in G$ be an element of $G$.
### Definition 1
The order of $x$ (in $G$), denoted $\order x$, is the smallest $k \in \Z_{> 0}$ such that $x^k = e_G$.
### Definition 2
The order of $x$ (in $G$), denoted $\order x$, is the order of the group generated by $x$:
$\order x := \order {\gen x}$
### Definition 3
The order of $x$ (in $G$), denoted $\left\vert{x}\right\vert$, is the largest $k \in \Z_{\gt 0}$ such that:
$\forall i, j \in \Z: 0 \le i < j < k \implies x^i \ne x^j$
## Infinite Order
$x$ is of infinite order, or has infinite order if and only if there exists no $k \in \Z_{> 0}$ such that $x^k = e_G$:
$\order x = \infty$
## Finite Order
$x$ is of finite order, or has finite order if and only if there exists $k \in \Z_{> 0}$ such that $x^k = e_G$.
## Examples
### Order of $2$ in $\struct {\R_{\ne 0}, \times}$
Consider the multiplicative group of real numbers $\struct {\R_{\ne 0}, \times}$.
The order of $2$ in $\struct {\R_{\ne 0}, \times}$ is infinite.
### Order of $i$ in $\struct {\C_{\ne 0}, \times}$
Consider the multiplicative group of complex numbers $\struct {\C_{\ne 0}, \times}$.
The order of $i$ in $\struct {\C_{\ne 0}, \times}$ is $4$.
### Order of $\begin{bmatrix} 1 & 1 \cr 0 & 1 \end{bmatrix}$ in General Linear Group
Consider the general linear group $\GL 2$.
Let $\mathbf A := \begin{bmatrix} 1 & 1 \cr 0 & 1 \end{bmatrix} \in \GL 2$
The order of $\mathbf A$ in $\GL 2$ is infinite.
### Rotation Through the $n$th Part of a Full Angle
Let $G$ denote the group of isometries in the plane under composition of mappings.
Let $r$ be the rotation of the plane about a given point $O$ through an angle $\dfrac {2 \pi} n$, for some $n \in \Z_{> 0}$.
Then $r$ is the generator of a subgroup $\gen r$ of $G$ which is of order $n$.
### Possible Orders of $x$ when $x^2 = x^{12}$
Let $G$ be a group.
Let $x \in G \setminus \set e$ be such that $x^2 = x^{12}$.
Then the possible orders of $x$ are $2$, $5$ and $10$.
## Also known as
Some sources refer to the order of an element of a group as its period.
## Also denoted as
The order of an element $x$ in a group is sometimes seen as $\map o x$.
Some sources render it as $\map {\operatorname {Ord} } x$.
## Also see
• Results about order of group elements can be found here. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9897925853729248, "perplexity": 165.33487115131513}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-39/segments/1568514573368.43/warc/CC-MAIN-20190918213931-20190918235931-00130.warc.gz"} |
http://physics.stackexchange.com/users/9719/colin-mcfaul?tab=favorites&sort=views | Colin McFaul
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### What is the physical meaning of complex eigenvalues?
nov 22 '14 at 16:18 Sparkler 1,027
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### Electric potential of a spheroidal gaussian
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5 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5660916566848755, "perplexity": 20003.3702355059}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-30/segments/1469257827791.21/warc/CC-MAIN-20160723071027-00078-ip-10-185-27-174.ec2.internal.warc.gz"} |
https://www.categories.acsl.org/wiki/index.php?title=Computer_Number_Systems&diff=prev&oldid=803 | # Difference between revisions of "Computer Number Systems"
All digital computers, from supercomputers to your smartphone, are electronic devices and ultimately can do one thing: detect whether an electrical signal is on or off. That basic information, called a bit (binary digit), has two values: a 1 (or true) when the signal is on, and a 0 (of false) when the signal is off. Larger values can be stored by a group of bits.
The number system is the system of naming or representing numbers. The number system we use in our daily life is known as Decimal number system because they are based on 10 different digits: 0, 1, 2, ..., 8, and 9. These numbers are called number with base-10. Base is generally written as subscript suffixed to a number. With base notation, the number "twelve thousand three hundred and forty-five" is written as $12345_{10}$. While we do not use the base-10 notation in our usual writing, we need to use it for other number systems. We will see the use of this base notation throughout this article to differentiate between numbers.
## Different Number Systems
In computer science, apart from the decimal system, three additional number systems are used. They are binary, octal, and hexadecimal. Binary systems is for the number system with base 2. Octal stands for the number system with base 8 while hexadecimal stands for the number system with base 16.
As you might guess, binary deals only with 2 digits — 0 and 1. Octal has 8 digits and hexadecimal has 16 unique digits. The table below displays the Number Systems with Base, Digits Used, and Sample Representation:
Number System Base Digits Used Sample Representation
Binary 8 0,1 $10110_{2}$
Octal 8 0,1,2,3,4,5,6,7 $75321_{8}$
Decimal 10 0,1,2,3,4,5,6,7,8,9 $97425_{10}$ or simply 97425
Hexadecimal 10 0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F $54321_{16}$
The letters A, B, C, D, E, and F represent an unique digit each in hexadecimal system where A stands for 10, B for 11, C for 12, D for 13, E for 14 and F for 15.
## Number of Bits to Hold All Digits
Since computer uses bits to store and process information, we need to understand the minimum requirement of bits for each number system.
As one bit can store either 0 or 1, it has a capacity of storing 2 values or $2^{1}$ values which is $2^{number\_of\_bits}$.
For 2 bits, the capacity increases to 4 different numbers which are 00, 01, 10, and 11. We can say 2 bits can store $2^{2}$ values. The capacity grows with the available bits in multiple of 2.
So to represent all Octal digits (8 digits), we need to allocate 3 bits as $2^3$ can accommodate 8 different values. And to assign all Hexadecimal digits (16 digits), we need to allocate 4 bits as $2^4$ = 16.
## Need for Octal and Hexadecimal Numbers
While computer can stores the numbers in bits (binary format) only, what is the need for Octal and Hexadecimal number systems?
Because binary numbers could get very long even for small decimal numbers, they grouped 3 binary digits together to form one base 8 digit and called that octal and grouped 4 binary digits together to form other base 16 digit and called that hexadecimal. The following table shows equivalent values in these bases:
Three digits (0 for left-most) Four digits (needed for base 16)
0000 = 0 1000 = 8
0001 = 1 1001 = 9
0010 = 2 1010 = A (10)
0011 = 3 1011 = B (11)
0100 = 4 1100 = C (12)
0101 = 5 1101 = D (13)
0110 = 6 1110 = E (14)
0111 = 7 1111 = F (15)
As you can see, the largest value that can be represented with 3 binary digits (when the first digit is a 0) is 7 and the largest value with 4 bits is 15. However, because all digits must be single characters, the letters A – F are used to represent the values 10 to 15. Therefore, in base 8, the digits must be 0 to 7 and in base 16 the digits must be 0 – 9, A – F.
## Formation of Numbers
The formation of any number goes by the digit multiplied by it's place value and adding them together. For example, we read and understand the number 12345 as twelve thousand three hundred and forty-five which has five digits: 1, 2, 3, 4, and 5. The number 12345 is completely different from the number 54321, which is also having the exact same 5 digits. This tells us that the digit with its place value give us the number. So, how to create/form a number in decimal system? Let's see using these 2 example numbers:
$12345 = 1×10000 + 2×1000 + 3×100 + 4×10 + 5×1 = 1×10^{4}+ 2×10^{3}+ 3×10^{2}+ 4×10^{1}+ 5×10{0}.$
$54321 = 5×10000 + 4×1000 + 3×100 + 2×10 + 1×1 = 5×10^{4}+ 4×10^{3}+ 3×10^{2}+ 2×10^{1}+ 1×10{0}.$
The expanded notation in the decimal number system above can represent different numbers by using powers of 10.
Since formation of a number follows the same rule in all number system, all other bases work the same way as follows:
$1101_{2} = 1 × 2^3 + 1 × 2^2 + 0 × 2^1 + 1 × 2^0 = 8 + 4 + 0 + 1 = 13_{10}$
$175_{8} = 1 × 8^2 + 7 × 8^1 + 5 × 8^0 = 1 × 64 + 7 × 8 + 5 × 1 = 64 + 56 + 5 = 125_{10}$.
$A5E_{16} = 10 × 16^2 + 5 × 16^1 + 14 × 16^0 = 10 × 256 + 5 × 16 + 14 × 1 = 2560 + 80 + 14 = 2654_{10}$.
Grouping Binary Digits for Octal and Hexadecimal Numbers
An easy way to convert between bases 2, 8, and 16 is by grouping bits together and using the table above.
$1001010110_{2} = \ \ 001\ \ \ 001\ \ \ 010\ \ \ 110_{2} = 1126_{8}$ and
$1001010110_{2} = 0010\ 0101\ 0110_{2} \ \ \ \ \ \ \ \ \ = 256_{16}$
Notice that grouping is always done starting with the last digit.
Using Hexadecimal Numbers to Represent Colors
Computers use hexadecimal numbers to represent various colors in computer graphics because all computer screens use combinations of red, green, and blue light or RGB to represent thousands of different colors. Two digits are used for each so the hexadecimal number “#FF0000” represents the color red, “#00FF00” represents green, and “#0000FF” represents blue. The color black is “#000000” and white is “#FFFFFF”.
The hash tag or number sign is used to denote a hexadecimal number. $FF_{16} = F (15) × 16 + F (15) × 1 = 240 + 15 = 255_{10}$ so there are 0 to 255 or 256 different shades of each color or $256^{3} = 16,777,216$ different colors.
The following web site has nearly every color name, along with its hex code and decimal values:
https://www.rapidtables.com/web/color/RGB_Color.html
For example “salmon” is “#FA8072” which represents the decimal numbers 250 (hex FA), 128 (hex 80), and 114 (hex 72).
## Resources
Ryan's Tutorials covers this topic beautifully. Rather than trying to duplicate that work, we'll point you to the different sections:
1. Number Systems - An introduction to what numbers systems are all about, with emphasis on decimal, binary, octal, and hexadecimal. ACSL will typically identify the base of a number using a subscript. For example, $123_8$ is an octal number, whereas $123_{16}$ is a hexadecimal number.
2. Binary Conversions - This section shows how to convert between binary, decimal, hexadecimal and octal numbers. In the Activities section, you can practice converting numbers.
3. Binary Arithmetic - Describes how to perform various arithmetic operations (addition, subtraction, multiplication, and division) with binary numbers. ACSL problems will also cover basic arithmetic in other bases, such as adding and subtracting together 2 hexadecimal numbers. ACSL problems will not cover division in other bases.
4. Negative Numbers - ACSL problems will not cover how negative numbers are represented in binary.
5. Binary Fractions and Floating Point - The first part of this section is relevant to ACSL: fractions in other bases. ACSL will not cover floating point numbers in other basis. So, focus on the section Converting to a Binary Fraction, but keep in mind that ACSL problems may also cover octal and hexadecimal fractions.
The CoolConversion.com online calculator is another online app for practicing conversion from/to decimal, hexadecimal, octal and binary; this tool shows the steps that one goes through in the conversion.
## Format of ACSL Problems
The problems in this category will focus on converting between binary, octal, decimal, and hexadecimal, basic arithmetic of numbers in those bases, and, occasionally, fractions in those bases.
To be successful in this category, you must know the following facts cold:
1. The decimal value of each hex digit A, B, C, D, E, F
2. The binary value of each hex digit A, B, C, D, E, F
3. Powers of 2, up to 4096
4. Powers of 8, up to 4096
5. Powers of 16, up to 65,536
## Sample Problems
### Sample Problem 1
Solve for $x$ where $x_{16}=3676_8$.
Solution: One method of solution is to convert $3676_8$ into base 10, and then convert that number into base 16 to yield the value of $x$.
An easier solution, less prone to arithmetic mistakes, is to convert from octal (base 8) to hexadecimal (base 16) through the binary (base 2) representation of the number:
\begin{align} 3676_8 &= 011 ~ 110 ~ 111 ~ 110_2 & \text{convert each octal digit into base 2}\hfill\cr &= 0111 ~ 1011 ~ 1110_2 & \text{group by 4 bits, from right-to-left}\hfill\cr &= 7 ~ \text{B} ~ \text{E}_{16} & \text{convert each group of 4 bits into a hex digit}\cr \end{align}
### Sample Problem 2
Solve for $x$ in the following hexadecimal equation: $x= \text{F5AD}_{16} - \text{69EB}_{16}$
Solution: One could convert the hex numbers into base 10, perform the subtraction, and then convert the answer back to base 16. However, working directly in base 16 isn't too hard. As in conventional decimal arithmetic, one works from right-to-left, from the least significant digits to the most.
The rightmost digit becomes 2, because D-B=2.
The next column is A-E. We need to borrow a one from the 5 column, and 1A-E=C
In the next column, 4-9=B, again, borrowing a 1 from the next column.
Finally, the leftmost column, E-6=8
Combining these results of each column, we get a final answer of $8BC2_{16}$.
### Sample Problem 3
How many numbers from 100 to 200 in base 10 consist of distinct ascending digits and also have distinct ascending hex digits when converted to base 16?
Solution: There are 13 numbers that have ascending digits in both bases from 100 to 200. They are (in base 10): 123 (7B), 124, 125, 126, 127 (7F), 137 (89), 138, 139 (8B), 156 (9C), 157, 158, 159 (9F), 189 (BD)
## Video Resources
There are many YouTube videos about computer number systems. Here are a handful that cover the topic nicely, without too many ads:
Number Systems - Converting Decimal, Binary and Hexadecimal (Joe James) An introduction to number systems, and how to convert between decimal, binary and hexadecimal numbers. Lesson 2.3 : Hexadecimal Tutorial (Carl Herold) The video focuses on hexadecimal numbers: their relationship to binary numbers and how to convert to decimal numbers. Hexes and the Magic of Base 16 - Vaidehi Joshi - May 2017' (DonutJS) A fun introduction to hexadecimal numbers, focusing a bit on using hex numbers for specifying RGB colors. Collins Lab: Binary & Hex (Adafruit Industries) A professionally produced video that explains the number systems, how and why binary numbers are fundamental to computer science, and why hexadecimal is important to computer programmers. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 2, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 1, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.4855135679244995, "perplexity": 1102.0665149039949}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-27/segments/1656103646990.40/warc/CC-MAIN-20220630001553-20220630031553-00349.warc.gz"} |
http://www.ipam.ucla.edu/abstract/?tid=14342&pcode=ELWS4 | ## Parameter uncertainty, model reduction, and effective theories in physics, biology, and beyond
#### Mark TranstrumBrigham Young University
The success of science is due in large part to the hierarchical nature of physical theories. These effective theories model natural phenomena as if the physics at macroscopic length scales were almost independent of the underlying, shorter-length-scale details. The efficacy of these simplified models can be understood in terms of parameter identifiability. Parameters associated with microscopic degrees of freedom are usually unidentifiable as quantified by the Fisher Information Matrix. I apply an information geometric approach in which a microscopic, mechanistic model is interpreted as a manifold of predictions in data space. Model manifolds are often characterized by a hierarchy of boundaries--faces, edges, corners, hyper-corners, etc. These boundaries correspond to reduced-order models, leading to a model reduction technique known as the Manifold Boundary Approximation Method. In this way, effective models can be systematically derived from microscopic first principles for a variety of complex systems in physics, biology, and other fields.
Back to Workshop IV: Uncertainty Quantification for Stochastic Systems and Applications | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8973988890647888, "perplexity": 648.5058350978362}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-47/segments/1510934804666.54/warc/CC-MAIN-20171118055757-20171118075757-00424.warc.gz"} |
https://vmlc.tamu.edu/Virtual-Math-Learning-Center/Courses/Functions,-Trigonometry-and-Linear-Systems/A-3 | # Section A.3 – Polynomials and Factoring
Section Details.
• Definition, properties, and terminology for polynomials
• Operations with polynomials
• Special products of polynomials
• Factoring polynomials
### Practice Problems
Directions. The following are review problems for the section. We recommend you work the problems yourself, and then click "Answer" to check your answer. If you do not understand a problem, you can click "Video" to learn how to solve it.
1. Factor the expression $$4x^2y^2-12xy+9$$
Answer: $$(2xy-3)^2$$
Solution: This is an example of a binomial square.
$$4x^2y^2=(2xy)^2 \text{, } 9=(3)^2\text{, and } 12xy=2(2xy)(3)$$
Therefore, $$4x^2y^2-12xy+9=(2xy-3)^2$$
To see the full video page and find related videos, click the following link.
2. Factor the expression $$10y^2-3y-1$$
Answer: $$(5x+1)(2x-1)$$
Solution: Need factors of $$10\cdot(-1)$$ that add up to $$-3$$.
Those factors are $$-5$$ and $$2$$, so we need to place them in parentheses in such a way that the inner terms multiply to $$2x$$ and the outer terms multiply to $$-5x$$:
$( \quad \quad \qquad )( \quad \quad \quad )$
$$10x^2$$ has factors of $$5x$$ and $$2x$$, which we can place in our parentheses like below.
$(5x\quad \quad )(2x\quad \quad )$
The outer terms should still multiply to $$-5x$$ and the inner terms to $$2x$$. $$1$$ obviously has factors of $$1$$ and $$1$$, so...
$(5x \quad 1)(2x \quad 1)$
Since the product of the outside two numbers needs to be $$-5x$$ and the inner two numbers need to have a product of $$2x$$, we get
$(5x + 1)(2x - 1)$
To see the full video page and find related videos, click the following link.
3. Factor the expression $$(x-1)(x^2+3)+(x-1)(x^2-5)$$
Answer: $$2(x-1)^2(x+1)$$
Solution: This type of problem is best factored using factoring by grouping.
Since each term has a factor of $$(x-1)$$, we can factor $$(x-1)$$ out.
\begin{align} (x-1)(x^2+3)+(x-1)(x^2-5) &=(x-1)[(x^2+3)+(x^2-5)]\\ &=(x-1)[2x^2-2]\\ &=2(x-1)(x^2-1)\\ &=2(x-1)(x+1)(x-1)\\ &=2(x-1)^2(x+1) \end{align}
To see the full video page and find related videos, click the following link.
4. Factor the following expression $$-6z^2+17z+3$$
$$(6z+1)(-z+3)$$
To see the full video page and find related videos, click the following link. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7816668152809143, "perplexity": 1171.9501272156376}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2023-14/segments/1679296949644.27/warc/CC-MAIN-20230331144941-20230331174941-00559.warc.gz"} |
https://brilliant.org/problems/a-geometry-problem-by-abhay-kumar-7/ | # A geometry problem by Abhay Kumar
Geometry Level 2
If $$\cos \theta - \sin \theta = \sqrt2 \sin \theta$$, which of the following is equal to $$\cos \theta + \sin \theta$$?
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https://arxiv.org/abs/1604.00456 | math.MG
(what is this?)
# Title: A note on the affine-invariant plank problem
Abstract: Suppose that $C$ is a bounded convex subset of $\mathbb{R}^n$, and that $P_1, \dots, P_k$ are planks which cover $C$ in respective directions $v_1, \dots, v_k$ and with widths $w_1, \dots, w_k$. In 1951, Bang conjectured that $$\sum_{i=1}^k \frac{w_i}{w_{v_i}(C)} \geq 1,$$ generalizing a previous conjecture of Tarski. Here, $w_{v_i}(C)$ is the width of $C$ in the direction $v_i$. In this note we give a short proof of this conjecture under the assumption that, for every $m$ with $1 \leq m \leq k$, $C \setminus \bigcup_{i = 1}^m P_i$ is a convex set.
Comments: 5 pages, 1 figure Subjects: Metric Geometry (math.MG) MSC classes: 52C17 Cite as: arXiv:1604.00456 [math.MG] (or arXiv:1604.00456v1 [math.MG] for this version)
## Submission history
From: Gregory R. Chambers [view email]
[v1] Sat, 2 Apr 2016 04:07:58 GMT (18kb,D) | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8045207858085632, "perplexity": 1179.690309458952}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-05/segments/1516084891705.93/warc/CC-MAIN-20180123012644-20180123032644-00162.warc.gz"} |
https://puzzling.stackexchange.com/questions/43145/ricky-mccormicks-notes | # Ricky McCormick's Notes
On June 30 1999, Ricky McCormick was found dead in an isolated area, 15 miles away from his home. He didn't own a car, and the area was not subjected to public transport so it is a mystery how he got there. The case has been identified as a murder, not a suicide as was first suggested.
Found in his pockets where two notes, seemingly encoded. The FBI, and other services, have tried decoding the notes unsuccessfully. The FBI has posted it online asking for help. If they have investigated it, and then asked for help, we can assume it's not just a case of bad spelling and handwriting. The notes are believed to tell us why he was murdered.
No-one has solved this mystery in 17 years....
Maybe one of you can?
Here are the notes:
Note 1:
P1
(MND MKNE M RSE-N-S-M-KNARE) (ACSM)
TFRNE NPINSE NPBSE RCB RNSE NPRSE INC
PRSE N MRSE OPRE HLD WLD NCBE (TFXLF TCXLF NCBE)
AL-PR PPI T XLY PPIY NCBE MGKSE WLD RCB RNSE PRSE
WLD RCB RNSE NT SSNE NTKSE-CRSLE-CITRSE WLD NCBE
AL WLD NCBE TSME LRSE RLSE U R GLSNE AS N WLD NCBE
(NOPFSE NLSRE NCBE) NTE G D DMN SENCURE RCBRNE
(TENE TFRNE NCBRTSE NCBE INC)
(FLRSE PRSE ON DE 71 NCBE)
(CDNSE PRSE ON SFE 74 NCBE)
(PR+SE PRSE ON REDE 75 NCBE)
(TF NRCMSP SOLE MRDE LUSE TOTE WLD N WLD NCBE)
(194 WLD’S NCBE) (TRFXL)
Note 2:
ALPNTE GLSE – SE ER+E
VLSE MTSE-CTSE-WSE-FRTSE
PNRTRSE ONDRSE WLD NCBE
N WLD XLRCMSP NE WLD S TS MEXL
DULMT 6 TUNSE NCBEXC
(MUNSARSTEN MU NARSE)
KLSE-LRSTE-TRSE-TRSE-MKSEN-MRSE
(SAEG NSE SE N MRSE)
NMNRCBRNSEP+E 2PTEWSRCBKNSE
26 MLSE 74 SPRKSE 29KCNOS OLE 175 RTRSE
35 SLE CLGSE UUNUTKEDKRSE PSESHLE
651 MTCSE HTLSE NCUTC TRS NMRE
99.84.52 UNEPLSENCRSEAOLTSENSKSENRSE
NSREONSE PUTSEWLD NCBE (3 XORL)
DNMSE NRSE 1N2 NTRLERC BRNSE NTSRCRSNE
LSPNSE N GSPSE MKSE RBSE NEBE AU XL 'R
HM CRE N MRE NCBE 1/2 MUNDDLSE
D-W-M-4 HPL XDRLX
Good luck...
• I've searched online for a csv version but haven't found one – Beastly Gerbil Sep 25 '16 at 20:09
• too many SE in the notes, sounds like junk note to me. – Oray Sep 25 '16 at 20:11
• @Oray, it is believed not. There is parts of english in there as well, for instance note 1 has 'first person' in brackets – Beastly Gerbil Sep 25 '16 at 20:15
• @MD, the FBI have investigated it and said it is a cipher. They have posted it online asking for help. I think if it was just bad spelling then they'd have realised that and not asked for help – Beastly Gerbil Sep 25 '16 at 20:24
• I assume the reference to 'first person' is the part that says "FI(?)RSEPRSEON" (and so the next line which says "CDNSEPRSEON" probably means 'second person'). – YowE3K Sep 26 '16 at 2:36
## 1 Answer
I will say that reading this at an hour past midnight, out in a small somewhat rural area, is definitely creepy! Poor Ricky.
!!! This answer is being presented as a ‘work in progress’.
First, the transcriptions provided seem to be rather careless, I must say. I will here provide new versions here. Given the shorthandish nature of the letters, and the inconsistent sizes of letter case, I will not transcribe diffferences of uppercase and lowercase. Written–over letters will be signified by the use of slant formatting. Questionable letters by bold formatting and so as to make them more visible, and parallel possibilities by special curly-brace notation. Be advised that I never transcribed any of these from the Notes:
{ } | ? , *
(There are a few places where the parser for the preview failed to render some formatting.)
## note 2, block 1
ALPNTE GLSE - SE ER+E
VLSE MTSE-CTSE-LWSE-FRTSE
PNTRTRSEON{D|P}KRSEWLD NCBE
NWLDXLRCMSP NEWLDSTSMEXL
PDULMT6TUNSE NC{R|B}EX{L|C}
## note 2, block 2
({A|N}MULNSAISTENMU NARSE)
{(|L}KLSE-LKSTE-TRSE-TRSE-MT{L|K}SE N-MLSE
(SAE{B|6}NSE SE N MBSE)
## note 2, block 3
NMN RLCB R NSE P+E 2PTWSRC BKN{X|S}E
26 MLSE 74SPRKS E 29*C*KC NO{3|L}{S|8}OLE I7SR7RSE
3S{S|5}6LE CLGSE {J|U}UNUT{X|K}EPDKRSE PSESHLE
6SI MTCSE HTLSE N CUTCTRS NMRE
99.84S 2UNE P LSE{N|V}CRSE***P***AORTSENSKSEN{???;B,L,S} SE
NSREONSE {P|D}VTSEWLDN CBE (3XORL)
## note 2, block 4
LDNMSE NRSE I N2 N TR{L|C}ERCBANSE NTSRCRS N E
LSPNSE N GSPSE MKSE R BSENEBE A{U|V} XLR
HM CR E N MRE N{C|L}BE 1/2MUNDDLSE
## note 2, block 5
D-W-M-4 H{P|B}L XDRLX
Regarding this Note 2, it seems that the scribe was becoming increasingly distressed with each additional block. Alas, the handwriting also invites several other possible interpretations.
Also, why is block 4 not complete? That right tip is missing; did Ricky draw the bubble like that? It's a toss–up as to whether I would've ended such a bubble on the edge of the paper or made loose lines, but I think it would be more likely that I'd squeeze the remaining letters and neatly round the edge of the bubble.
Given the similarity of the lettering and that presumption, I do not see it very likely that the blocks were written by different scribes imitating the original style.
I have a hunch that these notes were a journal of the scribe, made of travels planned or performed.
I strongly doubt that it was a cipher, unless he was paranoid or trained as a spy of some sort. There's no reason to take blind faith in anything anyone does, whether they belong to some group known as the FBI or not. If only they'd released the Notes sooner . . . In 2012 an interview with the family seems to cast a savantic light on Ricky. His ability to spell in accepted english was remarked as being poor or nonextant. He was described as being imaginative and with a penchant for the fantastic. The word ‘schizophrenic’ was used, but it did not say that he was clinically given that label by a psychiatrist.
It first seems to me like the scribe was encoding directions, locations, and distances in Note 1.
ALPNTE ALton PoiNT East
GLSE Green L South East
Et cetera.
However, the repetition of certain strings, e.g
TRSE
MLSE
makes it unlikely that such strings are simple places.
• It's a partial answer at least, albeit without much content yet. But since this is a real-life unsolved mystery which even the FBI couldn't solve, a complete answer might be too much to expect. I'll err on the side of not deleting this. – Rand al'Thor Oct 3 '16 at 12:37
• I suppose I should've made that clearer when I said “I will update this answer as I produce ideas.” Thanks for the vote of confidence! :-P – can-ned_food Oct 3 '16 at 20:12
## protected by Community♦May 11 '17 at 16:09
Thank you for your interest in this question. Because it has attracted low-quality or spam answers that had to be removed, posting an answer now requires 10 reputation on this site (the association bonus does not count).
Would you like to answer one of these unanswered questions instead? | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.650913655757904, "perplexity": 8938.327511703626}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-43/segments/1570986697439.41/warc/CC-MAIN-20191019164943-20191019192443-00200.warc.gz"} |
http://www.practicaldatascience.org/html/exercises/Exercise_missing.html | Missing Values Exercises¶
One of the defining features of pandas is the use of indices for data alignment. Like many features in pandas, it can make live very easy, but if you aren’t careful, it can also lead to problems. This is especially true because indices lead to behavior that is very different from what one sees in other languages and library (like R, numpy, and julia). So let’s spend a little timing practicing interacting with indices (and missing values)!
Exercise 1¶
Today, we will be using the ACS data we used during out first pandas exercise to examine the US income distribution, and how it varies by race. Note that because the US income distribution has a very small number of people with extremely high incomes, and the ACS is just a sample of Americans, the far right tail of the distribution will not be very well estimated. However, this data should suffice for helping to understand wealth inequality in the United States.
To begin, load the ACS Data we used in our first pandas exercise. That data can be found here. We’ll be working with US_ACS_2017_10pct_sample.dta.
Exercise 2¶
Let’s begin by calculating the median US incomes from this data (recall that income is stored in the inctot variable).
Exercise 3¶
Hmmm… That doesn’t look right. The average American is definitely not earning 1.7 million dollars a year. Let’s look at the values of inctot using value_counts(). Do you see a problem?
Now use value_counts() with the argument normalize=True to see proportions of the sample that report each value instead of the count of people in each category. What percentage of our sample has an income of 9,999,999? What percentage has an income of 0?
Exercise 4¶
As we discussed before, the ACS uses a value of 9999999 to denote that income information is not available for someone. The problem with using this kind of “sentinel value” is that pandas doesn’t understand that this is supposed to denote missing data, and so when it averages the variable, it doesn’t know to ignore 9999999.
To help out pandas, use the replace command to replace all values of 9999999 with np.nan.
Exercise 5¶
Now that we’ve properly labeled our missing data as np.nan, let’s calculate the average US income once more.
Exercise 6¶
OK, now we’ve been able to get a reasonable average income number. As we can see, a major advantage of using np.nan is that pandas knows that np.nan observations should just be ignored when we are calculating means.
But it’s not enough to just get rid of the people who had inctot values of 9999999. We also need to know why those values were missing. Suppose, for example, that the value of 9999999 was used for anyone who made more than 100,000 dollars: if we just dropped those people, then our estimate of average income wouldn’t mean much, would it?
So let’s make sure we understand why data is missing for some people. If you recall from our last exercise, it seemed to be the case that most of the people who had incomes of 9999999 were children. Let’s make sure that’s true by looking at the distribution of the variable age for people for whom inctot is missing (i.e. subset the data to people with inctot missing, then look at the values of age with value_counts()).
Then do the opposite: look at the distribution of the age variable for people who whom inctot is not missing.
Can you determine when 9999999 was being used? Is it ok we’re excluding those people from our analysis?
Note: In this data, Python doesn’t understand age is a number; it thinks it is a string because the original data has categories like “90 (90+ in 1980 and 1990)” and “less than 1 year old”. So you can’t just use min() or max(). We’ll discuss converting string variables into numbers in a future class.
Exercise 7¶
Great, so now we know why those people had missing data, and we’re ok with excluding them.
But as we previously noted, there are also a lot of observations of zero income in our data, and it’s not clear that we want everyone with a zero-income should be included in this average, since those may be people who are retired, or in school.
Let’s limit our attention to people who are currently working. We can do this using empstat. Remember you can use value_counts() to see what values of empstat are in the data!
Exercise 8¶
Now let’s estimate the racial income gap in the United States. What is the average salary for employed Black Americans, and what is the average salary for employed White Americans? In percentage terms, how much more does the average White American make than the average Black American?
Note: these values are not quite accurate estimates. As we’ll discuss in later lessons, to get completely accurate estimates from the ACS we have to take into account how people were selected to be interviewed. But you get pretty good estimates in most cases even without weights – your estimate of the racial wage gap without weights is within 5% of the corrected value.
Note: This is actually an underestimate of the wage gap. The US Census treats hispanic respondents as a sub-category of “white”, so in pooling what most Americans think of as “White” respondents (but which Census thinks of as “White, Non-Hispanic”) with Hispanic respondents (who tend to earn less), we get an underestimate of the average white salary in the US.
While all ethnic distinctions are socially constructed, and so on some level these distinctions are all deeply problematic, this coding is inconsistent with what most Americans think of when they hear the term “White”, which is though of as a category that is distinct from being Hispanic or Latino (categories which are also usually conflated in American popular discussion). With that in mind, most researchers working with US Census data split “White” into “White, Hispanic” and “White, Non-Hispanic” using race and hispan.
Want more practice?¶
(1) As noted above, these estimates are not actually quite correct because we aren’t using survey weights. To calculate a weighted average that takes into account survey weights, you need to use the following formula:
$weighted\_mean\_of\_x = \frac{\sum_i x_i * weight_i}{\sum_i weight_i}$
(As you can see, when $$weight_i$$ is constant for all observations, this just simplifies to our normal formula for mean values. It is only when weights vary across individuals that weights must be explicitly addressed).
In this data, weights are stored in the variable perwt, which is the number of people for which each observation is a stand-in (the inverse of that observations sampling probability).
Using the formula, re-calculate the weighted average income for both populations.
(2) Now calculate the weighted average income gap between non-hispanic White Americans and Black Americans.
Absolutely positively need the solutions?¶
Don’t use this link until you’ve really, really spent time struggling with your code! Doing so only results in you cheating yourself. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5186538100242615, "perplexity": 1113.1451598013566}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-43/segments/1570986660323.32/warc/CC-MAIN-20191015205352-20191015232852-00286.warc.gz"} |
http://www.soi.ch/node/416 | ## Posters
In his room, mouse Stofl has a wall on which he has put many posters. Since he is a lazy mouse, he never removes posters, and he sticks new posters over the old ones. So, some posters are overlapping others, but there are still some areas which are not covered. Now, Stofl would like to know how large this uncovered area is.
### Input
On the first line of standard input, you are given three integers separated by a single space: $W$, $H$, and $N$, the width and height of the wall, as well as the total number of posters. Each of the following $N$ lines contains four integers separated by a single space, describing one poster: $x_i$ and $y_i$, the horizontal and the vertical distance of the wall's top left corner to the poster's top left corner, followed by $w_i$ and $h_i$, the width and height of the poster.
### Output
Output one single integer, the area which is not covered by any poster.
### Limits
For every poster, we have $x_i, y_i \geq 0$ and $w_i, h_i > 0$, as well as $x_i+w_i \leq W$ and $y_i+h_i \leq H$.
If your program correctly handles all the cases with $1 \leq W,H,N \leq 200$, you score 70% of the points. For the full score, the limits are $1 \leq W,H \leq 10^9$ and $1 \leq N \leq 500$.
### Example 1
Input Output 8 6 3 1 1 3 2 6 1 2 2 3 2 2 3 33
### Example 2
Input Output 7 6 3 1 2 3 2 3 1 2 4 0 1 6 3 22
### Explanation
Below, you see what Stofl's wall looks like in sample test 1 and 2 (character '.' represents empty area, character '#' represents covered area).
........
.###..##
.####.##
...##...
...##...
........
.......
######.
######.
######.
...##..
....... | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5729963779449463, "perplexity": 476.96669670638784}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-40/segments/1443738099622.98/warc/CC-MAIN-20151001222139-00133-ip-10-137-6-227.ec2.internal.warc.gz"} |
https://manual.frontistr.com/en/theory/theory_04.html | # Heat Conduction Analysis
## Heat Conduction Analysis
In this section, the method of heat conduction analysis for solid bodies with the finite element methods used in this development code is described.
### Basic Equation
The heat conduction equation in a continuous body is as follows:
where,
$\rho = \rho(x)$ mass (density)
$c = c(x, T)$ specific heat
$T=T(x, t)$ temperature
$K=k(x, T)$ thermal conductivity
$Q=Q(x, T, t)$ calorific value
$x$ represents the position, $T$ represents the temperature and $t$ represents the time.
The area being considered is defined as $S$ and its surroundings as $\Gamma$. Assuming that Dirichet or Neumann-type boundary conditions are given throughout $\Gamma$, the boundary conditions become as follows:
The function form of $T_1$ and $q$ is known. $q$ is the outflow heat flux from the boundaries.
With this program, it is possible to consider three types of heat flux.
where $q_s$ is the distributed heat flux, $q_c$ is the heat flux by the convective heat transfer, and $q_r$ is the heat flux by the radiant heat transfer.
Furthermore,
$Tc=Tc(x,t)$ Convective heat transfer coefficient atomospheric temperature
$hc=hc(x,t)$ Convective heat transfer coeffcient
$Tr=Tr(x,t)$ Radiation heat transfer coefficient atmospheric temperature
$hr=\varepsilon\sigma F=hr(x,t)$ Radiation heat transfer coefficient
$\varepsilon$: radiation rate, $\sigma$: Stefan-Boltzmann constant, $F$: shape factor
### Discretization
If Eq.$\eqref{eq:2.4.1}$ is discretized with the Galerkin method,
However,
Eq.$\eqref{eq:2.4.8}$ is a formula of non-linear and non-steady-state. The objective now is to discretize it in time by the backward Euler method and calculate the temperature at time $t = t_0$ (when the temperature at $t = t_0+\Delta t$ is known) with the following equation:
The next step is to improve the temperature vector $\lbrace T \rbrace_{t=t_0+\Delta t}^{(i)}$ which approximately satisfies Eq.$\eqref{eq:2.4.13}$ to determine the solution $\lbrace T \rbrace_{t=t_0+\Delta t}^{(i)+1}$ with a good precision.
Therefore, the temperature vector must be expressed as follows:
The product of the heat transfer matrix and temperature vector, as well as the mass matrix, are expressed approximately by the following equations:
By substituting Eq.$\eqref{eq:2.4.14}$, Eq.$\eqref{eq:2.4.15}$ and Eq.$\eqref{eq:2.4.16}$ into Eq.$\eqref{eq:2.4.13}$, and omitting the terms of second or higher order, the following equation is obtained:
Moreover, the coefficient matrix of the left side is approximately evaluated with the following equation:
where $[K_T]^{(i)}_{t=t_0 + \Delta t}$ is a tangent stiffness matrix.
Finally, it is possible to calculate the temperature at time $t = t_0 + \Delta t$ through iterative calculation using the following equation:
In steady-state analysis, the iterative calculation is performed with the following equation:
In non-steady-state analysis, the discretization in time is done through the implicit method; thus, the analysis is normally not affected by the restriction of the size of the time increment $\Delta t$. However, if the time increment $\Delta t$ is to large, the number of convergences in the iterative calculation increases. Therefore, this program is equipped with an automatic increment function, which constantly monitors the dimension of the residual vector in the iterative calculation process. If the convergence of the iterative calculation is too slow, it decreases the time increment $\Delta t$. Moreover, when the number of iterative calculations is too small, it increases the time increment $\Delta t$. | {"extraction_info": {"found_math": true, "script_math_tex": 41, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 6, "equation": 10, "x-ck12": 0, "texerror": 0, "math_score": 0.8779803514480591, "perplexity": 522.9364464842713}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-49/segments/1637964362287.26/warc/CC-MAIN-20211202175510-20211202205510-00290.warc.gz"} |
https://cs.stackexchange.com/questions/116274/floating-point-arithmetic-on-division | # Floating point arithmetic on division
I am trying to figure out how $$(x/y)$$ in floating point arithmetic
$$fl(fl(x) / fl(y))$$ where $$fl(x) = x(1-\delta_1)$$, $$fl(y) = y(1-\delta_2)$$, $$fl = (1-\delta_3)$$
I have:
$$= x/y \cdot ((1-\delta_1)/(1-\delta_2))(1-\delta_3)$$
after arithmetic
$$= x/y \cdot (\delta_3 \delta_1 - \delta_1 - \delta_3 + 1)/(1-\delta_2)$$
Not sure how to fully write the rest I believe i have to shorten them using the info that $$\delta < \epsilon$$ and $$\delta^2 \leq \delta$$
$$\frac{1}{1 - \delta_2} = 1 + \delta_2 + \delta_2^2 + \delta_2^3 + \cdots$$
Then, for example, if $$\epsilon$$ is the machine epsilon and $$\delta_2 > 0$$:
$$1 + \delta_2 \le \frac{1}{1 - \delta_2} \le 1 + \delta_2 + \epsilon$$
That is quite a tight bound, when you think about it. (Exercise: Prove that this is true if $$\delta_2 \le 0$$, too.) | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 14, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9583632946014404, "perplexity": 293.1297029020646}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-05/segments/1579250606872.19/warc/CC-MAIN-20200122071919-20200122100919-00439.warc.gz"} |
http://www.alexejgossmann.com/Permute-Columns-Of-An-NMatrix/ | # NMatrix column permutations
Recently I got surprised by the behaviour of #permute_columns in the Ruby gem NMatrix.
Assume we have a matrix A consisting of five columns a0, a1, a2, a3, a4, and assume that we want to reorder them as a2, a0, a3, a4, a1. In Matlab or R we could easily supply the vector (3, 1, 4, 5, 2) as the column index in order to get the desired column permutation. With the current version of NMatrix however, we have to supply the array [2, 2, 3, 4, 4] as input to the method #permute_columns (additionally, the permutation array is not unique, see below).
The reason for this behaviour of NMatrix is that #permute_columns is using the laswp LAPACK function under the hood, where the permutation array represents a sequence of pair-wise permutations which are performed successively. That is, the ith entry of the array is the index of the column to swap the ith column with, having already applied all earlier swaps.
Thus, in our example with the permutation array [2, 2, 3, 4, 4] the following is happening:
1. In the original matrix swap column 0 with column 2: a2, a1, a0, a3, a4
2. In the result from previous step swap column 1 with column 2: a2, a0, a1, a3, a4
3. In the result from previous step swap column 2 with column 3: a2, a0, a3, a1, a4
4. In the result from previous step swap column 3 with column 4: a2, a0, a3, a4, a1
5. In the result from previous step swap column 4 with column 4: a2, a0, a3, a4, a1
Notice, that under this convention the permutation array is also not unique. For example [4, 3, 2, 1, 0] or [4, 1, 2, 3, 4] or simply [4] all yield the reordering a4, a1, a2, a3, a0.
A lot of times in scientific computation, one needs to reorder the columns of a matrix in a specific order. It seems very inconvenient having to sit down with a pen and a piece of paper in order to translate the new column order into the sequence of successive pair-wise permutations that the #permute_columns method is currently requiring (I think that most people would have to do that if they needed a more complicated permutation than swapping of two columns).
I thought that it would be nice to have a more intuitive Matlab-like behaviour for #permute_columns, where the method argument would be the desired new order of columns of the matrix. In order to not break back compatibility however, the intuitive behaviour of #permute_columns should be an option, while the current permutation would be the default behaviour. This can be achieved by introducing an argument :convention which can either can be :lapack (the default) or :intuitive. That is, in the example from above we would use the permutation vector [2, 0, 3, 4, 1] and set :convention to :intuitive in order to get the desired reordering a2, a0, a3, a4, a1.
So, a translation function is required which is going to take as input the Matlab-style permutation array and output a corresponding LAPACK-style permutation. Then the LAPACK-style permutation can be plugged into the existing column permutation algorithm.
I came up with a rather simple algorithm for such a translation. Basically, in the step i of the algorithm, the column which should be in position i in the end is going to be swapped with whatever column is at position i.
Assume the desired order of columns is given in the array final_order. We construct an array p of pair-wise permutations. Since the pair-wise permutation are performed successively, we need to keep track of the order of columns after every permutation. Therefore we initialize the array order = [0,1,2,3,4,...,n-1]. We run the following iterative procedure:
1. Swap order[0] with order[k] where k = final_order[0]. Save p[0] = k.
2. Swap order[1] with order[k] where k is the index such that order[k] = final_order[1]. Save p[1] = k.
3. Swap order[2] with order[k] where k is the index such that order[k] = final_order[2]. Save p[2] = k.
4. etc.
It is apparent that the procedure is going to produce a sequence of permutations, such that the ith permutation, puts the column which should be in position i in the end into position i.
Here is my implementation of #laswp! (#permute_columns merely calls it), which allows the user to use the intuitive Matlab-style column permutation by setting the option :convention to :intuitive.
#
# call-seq:
# laswp!(ary) -> NMatrix
#
# In-place permute the columns of a dense matrix using LASWP according to the order given as an array +ary+.
#
# If +:convention+ is +:lapack+, then +ary+ represents a sequence of pair-wise permutations which are
# performed successively. That is, the i'th entry of +ary+ is the index of the column to swap
# the i'th column with, having already applied all earlier swaps. This is the default.
#
# If +:convention+ is +:intuitive+, then +ary+ represents the order of columns after the permutation.
# That is, the i'th entry of +ary+ is the index of the column that will be in position i after the
# reordering (Matlab-like behaviour).
#
# Not yet implemented for yale or list.
#
# == Arguments
#
# * +ary+ - An Array specifying the order of the columns. See above for details.
#
# == Options
#
# * +:covention+ - Possible values are +:lapack+ and +:intuitive+. Default is +:lapack+. See above for details.
#
def laswp!(ary, opts={})
raise(StorageTypeError, "ATLAS functions only work on dense matrices") unless self.dense?
opts = { convention: :lapack }.merge(opts)
if opts[:convention] == :intuitive
if ary.length != ary.uniq.length
raise(ArgumentError, "No duplicated entries in the order array are allowed under convention :intuitive")
end
n = self.shape[1]
p = []
order = (0...n).to_a
0.upto(n-2) do |i|
p[i] = order.index(ary[i])
order[i], order[p[i]] = order[p[i]], order[i]
end
p[n-1] = n-1
else
p = ary
end
NMatrix::LAPACK::laswp(self, p)
end
Written on March 29, 2015 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7266006469726562, "perplexity": 1124.8717553872943}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-43/segments/1508187822668.19/warc/CC-MAIN-20171018013719-20171018033719-00874.warc.gz"} |
http://ufdc.ufl.edu/AA00006145/00001 | UFDC Home | Search all Groups | World Studies | Federal Depository Libraries of Florida & the Caribbean | Help
General theory of conical flows and its application to supersonic aerodynamics
Material Information
Title:
General theory of conical flows and its application to supersonic aerodynamics
Series Title:
NACA TM
Physical Description:
333 p. : ill. ; 27 cm.
Language:
English
Creator:
Germain, Paul, 1920-
United States -- National Advisory Committee for Aeronautics
Publisher:
NACA
Place of Publication:
Washington, D.C
Publication Date:
Subjects
Subjects / Keywords:
Superposition principle (Physics) ( lcsh )
Harmonic functions ( lcsh )
Aerodynamics ( lcsh )
Genre:
federal government publication ( marcgt )
bibliography ( marcgt )
technical report ( marcgt )
non-fiction ( marcgt )
Notes
Abstract:
The report deals with a method of studying the equation of cylindrical waves particularly indicated for the solution of certain aerodynamic problems. The method reduces problems of a hyperbolic equation to problems of harmonic functions. The study has been applied toward setting up the fundamental principles, to developing their investigation up to calculation of the pressures on the visualized obstacles, and to showing how the initial field of "conical flows" was considerably enlarged by a procedure of integral superposition.
Bibliography:
Includes bibliographic references (p. 261-263).
Statement of Responsibility:
by Paul Germain.
General Note:
"Report date January 1955."
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"Translation of "La théorie générale des mouvements coniques et ses applications a l̕ aérodynamique supersonique." Office National ď Études et de Recherches Aéronautiques, no. 34, 1949."
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Full Text
nCA--M -'31
qq^ 74l2'- q1-7-167S
GENERAL THEORY OF CONICAL FLOWS AND ITS APPLICATION
TO SUPERSONIC AERODYNAMICS
By
Paul Germain
Preface
By
M. J. Peres
NOTICE
This report deals with a method of studying the equation of cylin-
drical waves particularly indicated for the solution of certain problems
in aerodynamics. One of the most remarkable aspects of this method is
that it reduces problems of a hyperbolic equation to problems of harmonic
functions. We have applied ourselves here to setting up the fundamental
principles, to developing their investigation up to calculation of the
pressures on the visualized obstacles, and to showing how the initial
field of "conical flows" was considerably enlarged by a procedure of
integral superposition.
Such an undertaking entails certain dangers. In France the exist-
ence of conical flows was not known before 1946. Abroad, this question
has, for a long time, given rise to numerous reports which either were
not published or were published only after a certain delay. Thus it
must be pointed out that some of the results here obtained, original in
France when found, doubtlessly were not original abroad. Nevertheless
it seems possible to me to specify a certain number of points treated
in this report which, even considering the lapse of time, appear as new:
the parts concerning homogeneous flows, the general study of conical
flows with infinitesimal cone angles, the numerical or analogous methods
for the study of flows flattened in one direction, and a certain number
of the results of chapter IV. Moreover, even where the results which we
not always identical.
Another peculiarity should be noted. Since these questions actually
are everywhere the object of numerous investigations, progress has made
very rapid strides. This report edited at the beginning of 1948, risks
appearing, in certain aspects, slightly outmoded in 1949. To extenuate
this inconvenience we have indicated in a brief appendix placed at the
end of this report the progress made in these questions during the last
year. This appendix is followed by a supplementary bibliography which
indicates recent reports concerning our subject, or older ones of which
I should not have been able to successfully terminate this report
without the advice and support of my teacher, Mr. J. Peres, and it is
very important to me to express here my great respect for and gratitude
to him.
I should equally cite all those who directly or less directly have
contributed to my intellectual development and to whom I owe so much:
my teachers of special mathematics and of normal school, Mr. Bouligand
who directed my first reports, Mr. Villat, promoter of the Study of the
Mechanics of Fluids in France whose brilliant instruction has been of
the greatest value to me.
I also feel obliged to thank the directors of the O.N.E.R.A. who
have facilitated my task, and especially Mr. Girerd, director of aero-
dynamic research.
PREFACE
With his research on conical flows and their application, Mr. Paul
Germain has made a major contribution to the very timely study of super-
sonic aerodynamics. The present volume offers a comprehensive expose
which had been still lacking, an expose of elegance and solid construc-
tion containing a number of original developments. The author has fur-
thermore considered very thoroughly the applications and has shown how
one may solve within the scope of linear theory, by combinations of
conical flows, the general problems of the supersonic wing, taking into
account dihedral and sweepback, and also fuselage and control surface
effects. The analysis he develops in this respect leads him to methods
which permit, either by calculation alone or with the support of
electrolytic-tank experimentation, complete and accurate numerical
determinations.
After a few -preliminary developments (particularly on the validity
of the hypothesis of linearization), chapter I is devoted to the gener-
alities concerning conical flows. In such flows the velocity components
depend only on two variables and their determination makes use of har-
monic functions or of functions which verify the wave equation with two
variables according to whether one is inside or outside of the Mach
cone. Mr. Germain specifies the conditions of agreement between func-
tions defined in one domain or in the other and shows that the study of
conical flows amounts in general to boundary problems relative to three
analytical functions connected by differential relationships. He studies,
on the other hand, homogeneous flows which generalize the cone flows and
are no less useful in the applications.
From the viewpoint of the linear theory of supersonic flows one
must maintain two principal types of conical flows, bounded respectively
by an obstacle in the form of a cone with infinitesimal cone angle, and
by an obstacle in the form of a cone flattened in one direction.
The general investigation of the flows of the first type is entirely
Mr. Germain's own and forms the object of chapter II of his book. By a
subtle analysis of the approximations which may be legitimate Mr. Germain
succeeds in simplifying the rather complex boundary problem he had to
deal with; he replaces it by an external Hilbert problem. He shows how
it is possible, after having obtained the solution for an orientation
of the cone in the relative air stream, to pass, in a manner as simple
as it is elegant, to the calculation of the effect of a change in inci-
dence. He gives general formulas for the forces, treats completely
diverse noteworthy special cases and finally applies the method of trigo-
nometric operators which is also his own to the practical numerical
calculation of the flow about an arbitrary cone.
The determination of movements about infinitely flattened cones has
formed the object of numerous reports. The analysis which Mr. Germain
develops for this question (chapter III) contributes simplifications,
specifications, and important supplements. Thus he evolves, in the case
of an obstacle inside the Mach cone, a principle of minimum singularity
which enters into the determination of the solution. Mr. Germain gives
two original methods for treatment of the general case: one utilizes
the electrolytic-tank analogy, surmounting the difficulty arising from
the experimental application of the principle of minimum singularity;
the other, purely numerical, involves the trigonometric operators quoted
above.
In the last chapter, finally, Mr. Germain visualizes the composi-
tion of conical flows with regard to aerodynamic calculation of a super-
sonic aircraft. Concerning this subject he develops a complete theory
which covers most of the known results and incorporates new ones. He
concludes with an outline of the flows past a flat dihedral, with appli-
cation to the fins and control surfaces.
The creation of the National Office for Aeronautical Study and
Research has already made possible the setting up of groups of investi-
gators which do excellent work in several domains that are of interest
to modern aviation and put us on the level of the best research centers
abroad. Mr. Paul Germain inspirits and directs one of those groups in
the most efficient manner. He is one of those, and the present report
will suffice to bear out this statement, on whom we can count for the
development of the study of aerodynamics in France.
Joseph Peres
Member of the Academy of Sciences
NACA TM 1554
Pages
CHAPTER I GENERALITIES ON CONICAL FLOWS . 1
1.1 Equations of Supersonic Linearized Flows ... 1
1.2 Generalities on Conical Flows . .. 10
1.5 Homogeneous Flows . . ... ... .22
CHAPTER II CONICAL FLOWS WITH INFINITESIMAL CONE ANGLES ..... 30
2.1 Solution of the Problem . ... 30
2.2 Applications . . ... 41
Cone of Revolution . . ... .44
Elliptic Cone ....... . .. ..... 47
Study of a Cone With Semicircular Section . .. .58
2.5 Numerical Calculation of Conical Flows With
Infinitesimal Cone Angles . . .. .62
Calculation of the Trigonometric Operators ... 68
CHAPTER III CONICAL FLOWS INFINITELY FLATTENED IN ONE
DIRECTION . . . ... 79
5.1 Cone Obstacle Entirely Inside the Mach Cone ... 80
Study of the Elementary Problems (Symmetrical Cone ..... 80
Flows With Respect to Oxlx)) . .. ..80
Nonsymmetrical Conical Flows . .97
General Problem . . ... ...... 105
Rheo-Electric Method . .... .108
Purely Numerical Method ................. 117
5.2 Case Where the Cone Is Not Inside the Mach Cone () 152
Cone Totally Bisecting the Mach Cone (Fig. 28) ... 154
Cone Partially Inside and Partially Outside of the Mach
Cone (r) (Fig. 50) . . ... .. .142
Cone Entirely Outside of the Cone (C) (Fig. 29) . 152
5.5 Supplementary Remarks on the Infinitely Flattened
Conical Flows . . ... 159
CHAPTER IV THE COMPOSITION OF CONICAL FLOWS AND ITS APPLICATION
TO THE AERODYNAMIC CALCULATION OF SUPERSONIC AIRCRAFT .. 168
4.1 Calculation of the Wings . .. 168
Symmetrical Problems . . ... ... 171
Rectangular Wings . .... ..... 171
Sweptback Wings . . ... 186
Lifting problems . . ... ..... 206
Rectangular Wings . . ... 214
Effect of Ailerons and Flaps . ... .225
Sweptback Wing . . ... .. 229
The Lifting Segments . .... ... 240
4.2 Study of Fuselages . ... ... 243
4.5 Conical Flows Past a Flat Dihedral. Fins and Control
Surfaces . . ... . 251
vi
NACA TM 1554
Page
REFERENCES .. .. .. . ...... 261
APPENDIX ................. ........... 264
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TECHNICAL MEMORANDUM 1354
GENERAL THEORY OF CONICAL FLOWS AND ITS APPLICATION
TO SUPERSONIC AERODYNAMICS*
By Paul Germain
CHAPTER I GENERALITIES ON CONICAL FLOWS
1.1 Equations of Supersonic Linearized Flows
1.1.1 General Equation for the Velocity Potential
Let us visualize the permanent irrotational flow of a compressible
perfect fluid for which the pressure p and the density p are mutual
functions. The space in which the flow takes place will be fixed by
three trirectangular axes Oxl, Ox2, Ox3, the coordinates of a fluid
molecule will be xl, x2, x3, the projections on Oxi of the veloc-
ity V and of the acceleration A of a molecule will be denoted by
ui and ai, respectively.
The fundamental equations which permit determination
are the Euler equations
of the flow
-* 1 -
P
ai 1 6P
al P x,
the equation of continuity
*"La theorie ge6nrale des movements coniques et ses applications
a l'aerodynamique supersonique." Office National d'Itudes et de
Recherches Aeronautiques, no. 34, 1949.
1We employ the classic convention of the silent index: --pui
bxi v
is to be read: ~-(uI) + -~(Pu2)
JL d
S (Pu3)
6x
NACA U' 1354
div pV = 0
or x(Pui) = 0
(1.2)
and the equation of compressibility
p = f(p)
If one notes that
6ui
ai = u
1 k 6xk
and introduces the sonic velocity2
c2 dp
dp
the equation (I.1) assumes the form
p1 i
Sxi
_ 1 dp 6p
P dp 6xi
(1.3)
(1.4)
_ 2 ap
P 6xi
We introduce the velocity potential (xl, x2, x3), defined with
the exception of one constant, by
x -
Ui ox,
2The velocity of sound, introduced here by the symbol d_ has a
dp
well-known physical significance; it is the velocity of propagation of
small disturbances. This significance frequently permits an intuitive
interpretation of certain results which we shall encounter later on
(see section 1.1.4).
oui
lk
axk
(1.5)
NACA TM 1354
which is legitimate since we shall assume the flow to be irrotational.
If we make the combination
u.u i N D 620
Uiuk uk- xi xk xi 0xk
one sees, taking into account equations (1.5) and (1.2), that
6' 6c 620 26 24
63 2 c2 62 (1.6)
3xi Oxk 6xi 6xk 6x 2
i
This equation is the general equation for the velocity potential.
One may show, besides, that c is a function of the velocity modulus;
thus one obtains an equation with partial derivatives of the second
order, linear with respect to the second derivatives, but not completely
linear.
The nonlinear character of the equation for the velocity potential
makes the rigorous investigation of compressible flows rather difficult,
at least in the three-dimensional case.
In order to be able to study, at least approximately, the behavior
of wings., fuselages, and other elements of aeronautical structures, at
velocities due to the compressibility, one has been led to introduce
simplifying hypothesis which permit "linearization" of the equation for
the velocity potential.
1.1.2 The Hypotheses of Linearization and Their Consequences
For aerodynamic calculation, one may assume that the body around
which the flow occurs has a position fixed in space nd that the fluid
at infinity upstream is moving with a velocity U, U being a constant
vector, the modulus of which will be taken as velocity unit. We shall
always assume that the axis Oxi has the same direction as U; the
hypotheses of linearization amount to assuming that at every point of
the fluid the velocity is reasonably equivalent to U.
We put in a more precise manner
S= 1+u u2 = v u3 = W
NACA TM 1354
u, v, w are, according to definition, the components of the "pertur-
bation velocity."
(1) u, v, w are quantities which are very small referred to
unity; if one considers these quantities as infinitesimals of the first
order, one makes it at least permissible to neglect3 in the equations
all infinitesimals of the second order such as u2, v2, uv, etc.
(2) All partial derivatives of u, v, w with respect to the
coordinates are equally infinitesimals at least of the first order so
that one is justified in neglecting terms such as u -, etc.
0x1 k fx2
One may deduce from these hypotheses a few immediate consequences:
(a) At every point of the field, the angle of the velocity vector
with the axis Oxi is an infinitesimal of the first order at least.
Hence there results a condition imposed on the body about which the flow
is to be investigated; at every point the tangent plane must make a
small angle with the direction of the nondisturbed flow (this is what
one calls the uniform motion, defined by the velocity U).
If one designates by q the velocity modulus, one has, taking the
hypotheses setup into account
q2 = (1 + u)2 + v2 + w2 = 1 + 2u
whence
q= 1 u
(b) The pressure p and the density p differ from the values p,
and pl which these magnitudes assume at infinity upstream only by an
infinitesimal of the first order; the equation (1.5) is written in effect
au C1
6xl P1 xl
3This signifies that u, v, w may very well not be infinitesimals
of the same order; in this case one takes as the principal infinitesimal
the perturbation velocity component which has the lowest order.
NACA TM 1354
with cl denoting the sonic velocity at infinity upstream; thus
2 -
u 1 (P pl)
5
(1'7)
On the other hand, according to equation (I.4)
P Pl = c2 P) = -lu
If one defines the pressure coefficient Cp by
SP P
p l /2 12
one has
Cp = -2u
p
(1.8)
(c) Finally, an examination of what becomes of the equation for the
velocity potential (equation (1.6)) under these hypotheses shows that it
is reduced to
x2
12
1 2
1 xl
+ _
x22
Let p(x1,x2,x3) be the "disturbance potential," that is, the
potential the gradient of which is identical with the disturbance-
velocity vector; P (x,x2,x3) is the solution of the equation with
partial derivatives of the second order
2
1 Cl2 _2
2 2
c1 6x1
_ i _
2
dX2
(1.9)
+ 32
Ox,2
a completely linear equation.
x \
2
3
NACA fM 1354
The Mach number of the flow is called the dimensionless con-
stant M which, with the velocity unit to be chosen arbitrarily,
cl
is written here M = 1/c1.
We put: (M2 1) = 02, with e being equal +1 or -1 according to
whether M is larger or smaller than unity.
(1) If M < 1, equation (I.9) is written
2 a29 2 29
P2 2 + 2p + 2 =
6x12 6x22 6x 2
an equation which may be easily reduced to the Laplace equation.
This equation applies to flows called "subsonic" because the velocity
of the nondisturbed flow is smaller than the sonic velocity at infinity
upstream. These flows will not be investigated in the course of this
report .
(2) If M >1, equation (1.9) is thus written
2 a2, -2, +629
032 + (I.10)
ax12 6x22 6x32
This equation applies to "supersonic" flows; if one interprets xl
as representing the time t, this equation is identical with the equa-
tion for cylindrical waves, well-known in mathematical physics. Investi-
gation of this equation will form the object of this report.
Remarks.
(1) It should be noted that, in order to write the preceding equa-
tion, it was not necessary to specify the form of the equation for the
state of the fluid. In particular, the formulas written above do not
introduce the value of the exponent 7 of the adiabatic relation p = kpy
which is the form usually assumed by the equation of compressibility.
Investigation of linear subsonic flows has formed the object of
numerous reports. See references 1 and 2.
NACA TM 1354
(2) The preceding analysis shows clearly the very different char-
acter of subsonic flows which lead to an elliptic equation, and of
supersonic flows which are represented by a hyperbolic equation.
(3) When we wrote equation (I.9), we supposed implicitly that
M2 1 was not infinitely small, that is, that the flow was not "tran-
sonic," according to the expression of Von KArman5. Thus it is impossible
to make M tend toward unity in the results we shall obtain, in the
hope to acquire information on the transonic case6.
(4) It may happen, in agreement with the statement made in foot-
note 3, that u is an infinitesimal of an order higher than first. In
this case, one will take up again the analysis made in paragraph (b) of
section 1.1.2, which leads to a formula yielding the Cp, more adequate
than the formula (1.8)
Cp = -2u (v2 + w2) (.11)
1.1.3 Validity of the Hypotheses of Linearization
Any simplifying hypothesis leads necessarily to results different
from those which one would obtain with a rigorous method. Nevertheless,
it was shown in certain numerical investigations on profiles (two-
dimensional flows) where the rigorous method and the method of lineari-
zation were applied simultaneously that the approximation method provided
a very good approximation for the calculation of forces. Besides, it
is well-known that the classic Prandtl equation for the investigation of
5Study of the transonic flows, with simplifying hypotheses analogous
to those that have been made, requires a more compact analysis of the
phenomena. It leads to a nonlinear equation, described for the first
time by Oswatitsch and Wieghart (ref. 3). From it one may very easily
deduce interesting relations of similitude for the transonic flows
(ref. 4). One may find these relations also, in a very simple manner,
by utilizing the hodograph plane.
In a general manner, according to the values of M, one may be led
to neglect certain terms in the final formulas found for the pressure
coefficient Cp. This requires an evaluation, in every particular case,
of the order of magnitude of the terms occurring in the formulas when M
varies. In this report, we shall never enter into such a discussion.
We shall limit ourselves voluntarily to the general formulas. An inter-
esting example of such a discussion may be found in the recent memorandum
of E. Laitone (ref. 5).
NACA TM 1354
wings of finite span in an incompressible fluid furnishes very acceptable
results, and the Prandtl equation results from a linearization of the
rigorous problem.
It happens frequently, we shall have occasion several times to point
it out, that the solution found for u, v, w will not satisfy the
hypotheses of section 1.1.2 in certain regions (for example in the neigh-
borhood of a leading edge); eventually certain ones among these magni-
tudes could even become infinite.
Under rigorous conditions such a solution should not be retained.
Anyhow, if the regions where the hypotheses of linearization are not
satisfied are "sufficiently small," it is permissible to assume that the
expressions found for the forces (obtained by integration of the pres-
sures) will still'remain valid. This constitutes a justification
a posteriori for the linearization method so frequently utilized in
numerous aerodynamic problems7. Therefore, we shall not systematically
discard the solutions found which will not wholly satisfy the hypotheses
we set up.
1.1.4 Limiting Conditions. Existence Theorem
Physically, the definition of sonic velocity leads to the rule
which has been called the "rule of forbidden signals" (see footnote 2
of section 1.1.1) and which can be stated as follows:
A disturbance in a uniform supersonic flow, of the velocity U
produced at a point P, takes effect only inside of a half-cone of
revolution of the axis U and of the apex half-angle a = Arc sin(l/M);
(D cot a) a is called the Mach angle, the half-cone in question Mach
after-cone at P."
Correlatively, one may state that the condition of the fluid at a
point M (pressure, velocity, etc.) depends only on the character of
the disturbances produced in the nondisturbed flow at points situated
inside of the "Mach fore-cone at M;" the Mach fore-cone at a point is
obviously the symmetrical counterpart of the Mach after-cone with respect
to its apex.
If one wants to justify this rule from the mathematical viewpoint,
one must start out from the formulas solving the problem of Cauchy and
take into account the boundary conditions particular to the problem.
Along the obstacle one must write that the velocity is tangent to the
obstacle which gives the value dP/dn. Moreover, at infinity
7
For instance, in the investigation of vibratory motions of infin-
itely small amplitude about slender profiles.
NACA TM 1354
upstream (xl = -c) the first derivatives of ( must be zero, since 9
is, from the aerodynamic viewpoint, only determined to within a constant,
it will be assumed zero.
The characteristic surfaces of the equation (I.10) are the Mach
cones. If one of the Mach cones of the point P cuts off a region (R)
on a surface (Z), the classic study of the problem of Cauchy8 shows
that the value of 9 at P is a continuous linear function of the
values of 9 and of dcp/dn on R.
Let us therefore consider a point M of a supersonic flow such
that its fore-cone does not intersect the obstacle. We take as the
surface E a plane xl = -A, with A being of arbitrary magnitude.
On E, rP and dP/dn, which are continuous functions, will be arbi-
trarily small. Consequently the value of c at M is zero. Thus one
aspect of the rule of "forbidden signal" is justified.
Let ds suppose that the forward-cone of M cuts off a region r(M)
on the obstacle; on r(M), dc/dn is given by the boundary conditions;
thus 91(M) is a linear function of the values of C on r(M).
One sees therefore that, if one makes M tend toward a point MO
of the obstacle, one will obtain a functional equation permitting the
determination of P on the obstacle, at least in the case where the
existence and uniqueness of the solution will be insured9. Consequently,
((M) depends only on the values of CP/dn in the region r(M); this
justifies the fundamental result of the rule of "forbidden signals."10
1.1.5 General Methods for Investigation
of Linearized Supersonic Flows
In a recent articlell dealing with the study of linear supersonic
flows, Von Kirman indicates that two major general procedures exist for
8For the problem of Cauchy, relative to the equation for cylindrical
waves, see for instance references 6 and 7.
9Such a method has been utilized by G. Temple and H. A. Jahn, in
their study of a partial differential equation with two variables (ref. 8).
10A more exact investigation of this question may be found in
appendix 1, at the end of this report.
11See reference 4. A quick expose of the methods in question may
also be found in the text, in reference 2.
NACA TM 1354
the study of these flows, one called "the source method," the other
"the acoustic analogy."
The first is an old method and its theoretical application is
fairly simple. It consists in placing on the outer surface of the
obstacle a continuous distribution of singularities, called sources,
the superposition of which gives at every point of the space the desired
potential; the local strength of the sources may, in general, easily be
determined with the aid of the boundary conditions. The second method
utilizes a fundamental solution of the equation (I.10), the composition
of which permits one to obtain the desired potential; this procedure is
interesting in that it permits utilization of the Fourier integrals and
thus furnishes, at least in certain particular cases, rather simple
expressions for the total energy.
Von Karman also indicates, at the end of his report, a third general
procedure, that of conical flows.
We intend to investigate in this report the conical flows and
the development of this third procedure which utilizes systematically
the composition of the "conical flows" and, more generally, of the flows
which we shall call "homogeneous flows of the order n." We shall see
that this procedure permits one to find very easily, and frequently
with less expenditure, a great number of the results previously obtained
by other methods, and to bring to a successful end the investigation of
certain problems which, to our knowledge, have not yet been solved.
1.2 Generalities on Conical Flows
1.2.1 History and Definition
Conical flows have been introduced by A. Busemann (ref. 9) who has
given the principal characteristics of these flows and has indicated
briefly in what ways they could be utilized in the investigation of
supersonic flows. Busemann gives as examples some results, frequently
without proof. Several authors have supplemented the investigation of
Busemann: Stewart (ref. 10) has studied the case of the lifting wing A
to which we shall come back later on; L. Beschkine (ref. 11) has fur-
nished a certain number of results but generally without demonstration.
We thought it of interest to attempt a summary of the entire problem.
One calls "conical flows" (more precisely, "infinitesimal conical
flows")12 the flows in which there exists a point 0 such that along
12The adjective "infinitesimal" is remindful of the fact that the
flows have been linearizedd;" we shall henceforward omit this qualifica-
tion since no confusion can arise in this report.
NACA TM 1354
every straight line issuing toward one side of 0, the velocity vector
remains of the same value.
Let (i) be a plane not containing 0, normal to the vector U;
let us suppose only that the velocity vector at every point of (i) is
not normal to (r); the projection of these velocity vectors on (i)
determines a field of vectors, the lines of force of which we shall
call (y): the cones (a) of vertex 0 and directrix (7) are "stream
cones" for the flow.
More generally, let (S) be a stream surface of the flow, passing
through O; every surface deduced from (S) by homothety of the center 0
and of k, k being an arbitrary positive number, is a stream surface.
(S) is not necessarily a conical surface of apex 0, but having (S)
given as an obstacle does not permit one to foresee the existence of
such a flow. It is different if a conical obstacle of apex 0 is given;
the designation "conical flow" is thus justified.
Conversely, let us consider a cone of the apex 0, situated entirely
in the region xl >0, and suppose that a linearized supersonic flow
exists around this cone; this flow is necessarily a conical flow such
as has just been defined; in fact, if V(xlX2,x3) denotes this velocity
field, V( xl,Xx2,Xxj) ( being any arbitrary positive number) is
equally a velocity field satisfying all conditions of the problem; con-
sequently, if the uniqueness of the desired flow is admitted, 7 must
be constant along every half-straight line from 0 13.
Let us also point out that according to equations (1.8) or (I.ll),
the surfaces of equal pressure are also cones of the apex 0.
1.2.2 Partial Differential Equations Satisfied
by the Velocity Components
According to definition, the velocity components of a conical flow
depend only on two variables; on the other hand, as functions of xl,
13It should be noted that this argument will no longer be valid
without restriction in the case of a real supersonic flow around a cone
because in this case the principle of "forbidden signals" is no longer
valid in the rigorous form stated. Among other possibilities, a detached
shock wave may form upstream from the cone behind which the motion is
no longer irrotational.
NACA TM 1354
x2, x3, they are naturally the solution of the equation
S2f
6x3 2
O3
Let us first put
x2 = r cos 9
x3 = r sin 0
the equation then assumes the form
2 32f
6xl2
2 2
_ 2f r1 2 1 rf
or2 r2 602 r 3r
(1.12)
The second term of equation (1.12) is actually nothing else but
the Laplacian of f(x1,x2,x3) in the plane x2, x3 (xl being con-
sidered as parameter); naturally f(xl,r,8) is periodic in 8, the
period being equal to 2n.
To make the conical character of the flow evident, let us put
xI = prX
(I.13)
X is a new variable; X < 1 characterizes the exterior of the Mach
cone with the apex 0, X > 1 characterizes the interior of the cone.
Under these conditions, the disturbance-velocity components are func-
tions only of :. and e. Since f is a function of X and 0 only
d2f = 2 dx2
dx2
+ 232 dv dB +
ax 6e
02f
O82
+ 6f d2X + kf d2
5ax e
dX = r (dxl OX dr)
o~r\ 1I
d2x = -L(d2x X d2r -
pr
2dr dx 1 + 20 X dr2)
r r
2 62f
6x 2
_ 2f
bx22
NACA TM 1354
2f
;r2
62f
6e2
6f are the respective coefficients of dxl2,
Tr
dr2,
d2r in the expression of d2f as a function of the vari-
s xl, r, e.
As a consequence, the equation (1.12) becomes under these conditions
r(x2
6-A.O2
(1.14)
+ b2f + f = 0
+02 -
6e2 ax
One may try to simplify this equation further by replacing the
variable X by the variable t, X and t being connected by a rela-
tionship X = X()), and by making a judicious choice for the func-
tion x(S). The first operation gives
(x2 2 i)
6t2
+ y,2 r
602
+ B 0
6 at (x. )x' =
oS X'
with the primes denoting derivatives with respect to E.
this equation, one may make the term in disappear.
realized by putting
(1) If X >1,
For simplifying
This will be
X = ch e
one obtains for f Laplace's equation
62f
6t2
+ 2
S62
(1.16)
(2) If X < 1,
= cos 1 (I.17)
in this case, one obtains the equation for waves with two variables
62f
3,2
62f
682
(I.18)
(1.15)
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Geometrical interpretation.- X > 1 corresponds to the interior of
the Mach rearward cone (r) of the point 0; every semi-infinite line,
issuing from 0, inside of this cone, has as image a point 8, E. One
will assume, for instance, -n < 0 < i; k = 0 corresponds to the
cone (r), E = w corresponds to the cone axis (it will always be pos-
sible to assume as positive). The image of the interior of (r)
forms therefore on the region (A) of the plane (0,a) (fig. 1), limited
by the semi-infinite lines AT, A'T' and by the segment AA'. The
correspondence is double valued in the sense that to a semi-infinite
line issuing from 0 there corresponds one point and one only (0e,)
in the bounded region and conversely, to one point of this region there
corresponds one semi-infinite line, and one only, issuing from O,
inside of (r).
Since we shall suppose, in general, that the cone investigated is
entirely in the region xl > 0, only this region will be of interest
(P then being identically zero for xl < 0). The semi-infinite lines
of this region issuing from 0, outside of (r), correspond to 0 < X < 1
(fig. 2), that is, according to equation (I.17), 0 < r < !L; n = 0
2
corresponds to the cone (F), T = n to the plane xI = 0; the semi-
2
infinite lines issuing from 0 correspond biunivocally to the points
of the region (A'), inside of the rectangle AA'B'B in the plane (e,r).
Summing up, the velocity components satisfy the simple equa-
tions (I.16) and (I.18), the first of which is relative to the region (A),
the second to the region (A').
1.2.3 Fundamental Theorem
The equation (1.14) which represents the fundamental equation of
our problem is an equation of mixed type; it is elliptic or hyperbolic
according to whether is larger or smaller than unity. In order to
study this equation in a simpler manner, we have been led to divide the
domain of the variables into two parts and to represent them on two
different planes. How an agreement will be reached between the solutions
obtained for f in the two planes that is the question which will be
completely elucidated by the following theorem which will be fundamental
in the course of our investigation.
Theorem: There exists "agreement" as to X = 1 for all derivatives of
f, defined in either the region (A) or (A'), provided that there is
"agreement" for the function itself.
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In fact, let us take two functions fl(e,), f2(6,Ti), the first
satisfying the equation (1.16) in the region (A), the second the equa-
tion (I.18) in the region (A'), both assuming the same values c(e) on
the respective segments ( 0 = 0, -i < 0 < n) (r = 0, -n < 0 < i). Let
Inf
B0 be the abcissa of a point of AA'. If 6nfL(80,0) exists,
8en
Sd-; consequently
den
nf 2 (0,0)
en
exists and
ae oO
aen
a3f(e,, )
- On
Let us now pass to the investigation of the derivatives of the
order n of the form nf the equation (1.14) shows first that
6Xoen-1
f(e,1) =- -f(,1)
OX 602
which proves that all partial derivatives of the order 1 with respect
to X have the same value on (P), whether they are calculated starting
from fl or from f2. The argument develops without difficulty through
recurrence. By deriving equation (1.14) n times with respect to :
and making X = 1, one obtains
(2n + 1) + n2 + -6nf 0
An+1 .a 2" 2n
which finally shows that the values n+f can be uniquely expressed
ae. n
as a function of the derivatives of f(0) with respect to G and that
they, consequently, have the same value, whether calculated starting
from fl or from f2.
Summing up, one may say that it is sufficient for the establishment
of the "agreement" between two solutions defined in (A) and (A'), if
these solutions assume the same value on the segment AA'.
anfl(00
agn
16 NACA TM 1354
1.2.4 Mode of Dependence of the Semi-Infinite
Lines Issuing From 0
If one puts in the plane (e0,)
8 + T = 2X 8 q = 2 (1.19)
one sees that the characteristics of the equation (I.18) are the parallels
to the bisectrices K = cte, = cte. These characteristics are, in
the plane (1,e), the images of the planes
xI = -r cos(2A 0) and xl = or cos(O 2P)
which are the planes tangent to the cone (P). The characteristics
passing through a point s0(O0,0) are the images of two planes tangent
to the cone (r) which one may lay through the semi-infinite A0 cor-
responding to the point 60 of the plane (8,0) (fig. 3). The gener-
atrices of contact are characterized on the cone by the values 81
and 82 of the angle 0. One encounters here a result which seems to
is immediately explained if one notes that, since all points of a semi-
infinite A0 issued from 0 are equivalent, one must consider at the
same time all Mach cones, the apexes of which are situated on A0; the
group of these cones admits as envelope precisely the two planes tangent
to the cone (r) passing through A0. We shall call "Mach dihedron
posterior" to the semi-infinite A0 that one of the dihedra formed by
the two planes which contains the group of the Mach cones to the rear of
the points of A0. The region inside ot this dihedron and outside of
the cone (r) has as image in the plane (0,rj) the triangle 01 5062.
A semi-infinite A1 will be said to be dependent on or independent of
A0 according to whether the image of A1 will be inside or outside of
the triangle 81 6082. This argument also explains why the equa-
tion (1.14) shows elliptic character inside of (r). More precisely,
two semi-infinite lines A1 and 62, inside of (r), are in a state of
neutral dependence (ref. 9). In fact, let M1 be a point of Ak, M2
a point of 2; let us suppose that Mi is outside of the Mach forward
cone of M2; according to the argument of section 1.1.4 the point M2
seems to be independent of Ml; but on the other hand, if one assumes Mi'
NACA TM 1354
to be a point of A1, inside of the Mach forward cone of M2, M1'
and M1 are equivalent which explains that M2 is actually not inde-
pendent of M1 (fig. 4).
1.2.5 The Conditions of Compatibility
Thus one may foresee how the solution of a problem of conical flow
will unfold itself. One will attempt to solve this problem in the
region (A') which will generally be fairly easy since the general solu-
tion of the equation (1.18) is written immediately by adjoining an arbi-
trary function of the variable 6 + n to an arbitrary function of the
variable 6 q. This will have the effect of "transporting" onto the
segment AA' the boundary conditions relative to the region (A').
Applying the fundamental theorem, one will be led to a problem of har-
monic functions in the region (A). But taking as unknown functions the
components u, v, w, of the disturbance velocity, we have introduced
three unknown functions (while there was only one when we dealt with
the function C). One must therefore write certain relationships of
compatibility which express finally that the motion is indeed irrotational.
The motion will be irrotational if u dxI + v dx2 + w dx3 is an
exact differential which will be the case when, and only when
x1 du + x2 dv + x dw = r(py du + cos 8 dv + sin 0 dw)
is an exact differential. This can occur only if this expression
is identically zero, with u, v, w being functions uniquely of 0
and of X (the total differential not containing a term.in dr must
be independent of r):
In a conical flow the potential is written
P = uxl + vx2 + wx3 = r(puX + v cos 0 + w sin e)
with u, v, w being the disturbance-velocity components.
One will note that C, is proportional to r.
Moreover
OX du + cos 0 dv + sin 0 dw = 0
(1.20)
18 NACA TM 1354
This is the relationship which is to be written, and this is the
point in question, on one hand in the plane (C,0), on the other in the
plane (6,).
(a) Relations in the plane (0,q). One may write
u = ul(?) + u2(p)
and analogous formulas for v and w, X and
relations (I.19). One has in particular
dUl 3u + u du2 u
dX 5q 60 du o0
Besides, according to equation (1.20)
- being defined by the
P cos T dul + cos 0 dvl + sin 0 dwl = 0
(1.21)
3 cos T du2 + cos 0 dv2 + sin 0 dw2 = 0
however: 0 = x + P, T = A 1; and consequently the first equa-
tion (1.21) is written
cos r 1 cos K dui + cos K dvI + sin k dwli +
sin psin du sin K dv1 + cos K dw = 0
since the two quantities between brackets are unique functions of
the preceding equality causes
p cos K dul + cos K dvi + sin X dwl = 0
P sin k dul sin X dv1 + cos K dwI = 0
dv1
-p dul = 1
cos 2X
dwl
sin 2X
(1.22)
NACA TM 1354
In the same manner one will show that
dv2 dw2
-p du2 = --
cos 2Ii sin 21
(1.23)
(b) Relations in the plane (e,t).
The calculation is perfectly analogous. The equation (1.16) causes
us to introduce the complex variable 0 = 8 + it and the func-
tions U(.), V(C), W(t), defined with the exception of an imaginary
additive constant, the real parts of which in (A) are, respectively,
identical to u(e,a), v(0,t), w(e,t).
The equation'(I.20) permits one to write
0 ch t dU + cos 0 dV + sin 0 dW = 0
If one puts
e + it =
e iE5 =
one obtains
cos T L
2sin
sin [
cos dU + cos -
2 2
sin dU sin -
2 2
dV + sin dW +
2
dV + cos -
2
thence one concludes as previously
- dU dV dW
cos ( sin c
The formulas (I.22), (1.23), (I.24) express the relationships of
compatibility which we had in mind.
dW = 0
(1.24)
NACA TM 1354
Remark.
We shall utilize frequently the conformal representation for studying
the problems relative to the domain (A). If one puts, in particular
Z = eit = e- ei
one sees that (A) becomes in the plane Z the interior area of the
circle (CO) with the center 0 14 and the radius 1 (fig. 5).
If one puts Z = pe the point Z is the image of a semi-infinite
line, issuing from the origin of the space (xl,x2,x3), characterized
by the angle 6 and the relationship
X1_ 1 + p2
pr 2p
The origin of the plane Z corresponds to the axis of the cone (P),
the circle (Co) to the cone (r) itself. A problem of conical flow
appears in a more intuitive manner in the plane Z than in the plane f.
In the plane Z, the formulas (1.24) are written
SdU = 2Z dV = 2iZ dW (1.25)
Z2 + 1 Z2 1
We shall moreover utilize the plane z defined by
S 2Z
Z2 + 1
The domain (A) corresponds conformably to the plane z notched by
the semi-infinite lines Ax, A'x' (fig. 6), the cone (r) at the edges
of the cuts thus determined, and the axis of the cone (F) at the origin
14
No confusion is possible between the point 0, origin of the sys-
tem of axes xl, x2, x3 and the point 0, here introduced as the
origin of the plane Z.
NACA TM 1354
of the plane z. The relations of compatibility in the plane z then
assume the form
-0 dU = z dV iz dW (1.26)
1 -z2
1.2.6 Boundary Conditions
The Two Main Types of Conical Flows
The boundary conditions are obtained by writing that the velocity
vector is tangent to the cone obstacle. Let, for instance, x2(t), x3(t)
be a parametric representation of the section xI = 0 of the cone;
x3x2' x2x'3, xx3', -PY2' constitute a system of direction parameters
of the normal to the cone obstacle, and the boundary condition reads
x' vx3' = (x3x2' x2x3' (1 + u) (1.27)
It will be possible to simplify this condition according to the
cases. However, the simplification will have to be treated in a dif-
ferent manner according to the conical flows investigated. As set forth
in section 1.1.2, two main types of conical flows may exist.
(1) The flow about cones with infinitesimal cone angles, that is,
cones where every generatrix forms with the vector U an angle which
remains small. Naturally, the cone section may, under these conditions,
be of any arbitrary form; since the flow outside of (P) is undisturbed
(velocity equivalent to U), on the cone (r) u, v, w are zero.
The problem may have to be treated in the plane Z; U(Z), V(Z),
W(Z) will have real parts of zero on (CO). The image (C) of the
obstacle, in the plane Z, is defined by a relation p = f(e); conse-
quently, a parametric representation of the section xi = p will be
obtained by means of the formulas
2p 2p
X2 = 2 cos e X3 sin G
1 + p2 1 + p2
NACA TM 1354
Thus the condition (1.27) becomes
w sin 0 p' cos a + p2(p sin e + p' cos 8) +
v cos 0 + P' sin e + 2(p cos 0 p' sin 8) = 2-(1 + u) (1.28)
with 0 taken as parameter, and p' denoting the derivative of p
with respect to 0. The investigation of conical flows with infinitesimal
cone angles will form the object of chapter II.
(2) The flow about flattened cones, that is, cones, the generatrices
of which deviate only little from a plane containing U. Let us remember
that (section 1.1-.2) the tangent plane is to form a small angle with 6;
consequently, rigorously speaking, the section of such a cone cannot be a
regular closed curve, an ellipse for instance; it must present a lentic-
ular profile (fig. 7). In chapter III we shall study the flows about
such cones.
Remark.
Actually, we have, therewith, not exhausted all types of conical
flows, that is, those for which linearization is legitimate. One may,
for instance, obtain flows about cones, the section of which presents
the form shown in fire 8; the axis of such a cone has infinitely small
inclination toward U.
Before beginning the study of these flows we shall, in order to
terminate these generalities, introduce a generalization of the flows,
the possible utilization of which we shall see in a final chapter.
1.3 Homogeneous Flows
1.3.1 Definition and Properties
The conical flows are flows for which the velocity potential is of
the form
cP = rf(e,X)
as we gad seen in section 1.2.5. One may visualize flows for which
P = rnf(0,x)
NACA TM 1354
We shall call them homogeneous flows of the nth orderl5. The conical
flows defined in section 1.2 are, therefore, homogeneous flows of the
order I. However, we shall maintain the expression "conical flow" to
designate these flows since this term has been used by numerous authors
and gives a good picture.
The derivatives of the velocity potential with respect to the vari-
ables xl, x2, x3 all satisfy the equation (I.10). If one then con-
siders the derivatives of the nth order of the potential of an homogeneous
flow of the nth order, one finds that they depend only on X. and a
and satisfy the equation (1.14); the analysis made in section 1.2.2
remains entirely valid. One may make the changes in variables (I.15)
and (T.17) which lead to the equations (1.16) and (1.18). Thus one has
here a method sufficiently general to obtain solutions of the equa-
tion (I.10) which may prove useful.
The simplest flows are the homogeneous flows of the order 0 which
do not give rise to any particular condition of compatibility. For the
flows of nth order, in contrast, one has to write a certain number of
conditions connecting the derivatives of nth order. We shall examine16
as an example the case of homogeneous flows of 2nd order.
There are six second derivatives which we shall denote Tij (i
and j may assume independently the values 1, 2, 3), Cij designating
4 Outside of (r) we shall put
6xi 6xj
ij ij i
1 2
with P.ij being a function of X only, Pij2 of p only (see for-
mula 1.19). Inside of (r), ij. is the real part .of a function .i.(U).
In order to obtain the desired relations, it is sufficient to note
that
15The definition for homogeneous flows of the nth order has been
given for the first time by L. Beshkine (ref. 11); this author, by the
way, calls them conical flows of the nth order. One may also connect
this question with the article of Hayes (ref. 12).
S6ee appendix 2.
NACA TM 1354
ij dxj = dPi
and to apply the results of section 1.2.5; thus one may write the fol-
lowing six relations between the c 1
-0 dil 1 d 1 d 1 (i = 1,2,3)
11 cos 2X 12 sin 2X i3
which, besides, are reduced to five as one sees immediately. One will
have analogous relations for the functions Cpj2 (it is sufficient to
exchange the role of X and of p).
Finally, one has for the analytic functions oij()
d 1 d 1 d3
ii cos i i2 sin i i3
namely six relations which as before are reduced to five. The written
conditions are not only necessary but also sufficient since the func-
tions Pi necessarily are the components of a gradient. Thus one sees
that there is no difficulty in writing the conditions of compatibility
for a homogeneous flow of nth order.
1.3.2 Relations Between the Homogeneous Flows
of nth and of (n-l)th Order
We shall establish a theorem which can be useful in certain prob-
lems and which specifies the relations existing between homogeneous
flows of nth and of (n-1)th order; we shall examine the case where n = 1.
1.3.2.1.- Let us consider inside of the cone (P) a homogeneous
flow of the order 0 defined by
f = REcZ)]
NACA TM 1354 2
We shall first of all seek the components u, v, w of the dis-
turbance velocity
dC = u dxI + v dx2 +
wdx = R[O'(Z) dz = R[Zs'(Z) d
then
1 + p2
xl = pr 2
2P
thus
dZ = dp + i d0
Z p
x2 = r cos 0
x3 = r sin 8
_ 2 + 1 dx x2 dx2 + x2 dx
p2 1L r2
Sx2 dx3 x3 dx2
r2
whence one deduces
p2 + 1 1
p2 1 1-
v cos P02 + 1
r P2 1
w sin 8 02 + 1
r p2 1
R[Zq'(Zz] + sin e T[ Z'(z]
R-Zo'(Z CS- '(Z
~r -
p2 + 1 sin 0
P
p2-1 sin 0
P
however
Z 1
z
Z
z
p2 + 1
P21
_ 2 -
p
cos 8 + i
cos e + i
NACA 4M 1354
hence the result
1
u
xl
xl
p2 + 1 R Z'(Z)
p2
p2 +1
p2 -1
p2 1
R [- (Z2 + 1)'(Z)
R (2 1)0,(Z)]
R- 2 1)01(z
(1.29)
1.3.2.2.- Let us now consider a point O' (xI = E1, x2 = 0, x3 = 0),
El being a very small quantity. Let M be a point with the coordi-
nates (xl,r,e) with respect to O, inside of (F), and with the para-
meters (p,8) in the plane Z. For the conical flow (homogeneous of
Ist order) with the vertex 0', its coordinates are: (xl- E r, a) and
its parameters in the Z-plane:
( p2 1 1
since
dxI = 1 = Br
p2 1
2p2
dp = x 2 1 dp
do = x p
p + 1
Let us then consider two identical conical fields but with the
apexes 0 and 0', and form their difference. We shall obtain a
velocity field which, due to the linear character of the equation (I.10),
will satisfy this equation. If
U0 = R[(Z)
denotes the component u of the field with the vertex
component u in the "difference field"
0, one has as
u = +RF(Z) R 2 + 1 z
P2 X1 ]
- P2 + 1 1 RFZF'(Z)
p2 1 xl
~~2
(I.30)
NACA TM 1354
El being considered as infinitely small. Moreover, according to the
relations (1.25), the components v and w are written
v = 2 + 1 aE fi (Z2 + 1)F'(Z]
w l p2 +- i PZ2 1)F'(Z)
xi p2 1 2
1.3.2.3.- Let us consider the point 0''(O,E2,0), with E2 being
a small quantity.' Let M be a point with the coordinates (x1,r,O)
with respect to 0, inside of (r), with the parameters (p,8) in the
plane Z. For the flow with apex 0'', the coordinates of M are
(x1, r E cos 8, 0 + E2 sin as can be easily stated by projecting
M in m on the plane x2x3 (fig. 9). But on the other hand
2xd 1 2
dr dp = -C2 cos 0
( (1+p2)2
r de x P dO = 2 sin 0
1 + p2
thus
dZ = e p + ip d] = e2 12 2 x i sin e cos 8 + e1i
with Z + dZ representing the point M in the conical field with the
vertex 0''.
Let us then consider two identical conical flows, but with the
apexes 0 and 0'', and form their difference. We shall obtain a
velocity field which due to the linear character of the equation (I.10)
will satisfy this equation. If
O = R[G(Z)
28 NACA TM 1354
denotes the component v in the field of the vertex 0, one has a com-
ponent v in the "difference field"
v +n[G(Z) R[(Z + dZ) = -R[G'(Z)dZ]
Cx2 P2 +_1 2) + i sin 1(P2
= p-- R G'(Z) cos e ( + p2) + i sin e(p2 l)e
S2 P 2+ 1 R ZG'(Z) Z +1
2x1 2 -1 2
2x p2 1-L Z/j
x1 P2 1 2 (1.32)
besides, according to equation (I.25), the components u and w are
written
E2 02 + 1
1 po' 1
(1.33)
w =2 p2 + 1 R (Z2 1)G'(Z]
x p2 1 2
1.3.2.4.- With these three lemmas established, it is easy to demon-
strate the property we have in mind. Let us call "complex potential" of
a homogeneous flow of zero order the function ((Z) (section 1.3.2.1)
so that
P = R [0(Z)]
so that the function of complex variable, the real part of which gives
insideof (P) the projection of the disturbance velocity in the direc-_
tion i, is the "complex velocity" of a conical field in the direction 1;
so that, finally, the velocity field obtained by the difference of two iden-
tical conical fields, the verties of which are infinitely close and
ranged on a line parallel to 1, is the "field derived from a conical
flow" in the direction 1; then we may state:
NACA TM 1354
Theorem: The field derived from a conical flow in the direction Z is
the velocity field of a homogeneous flow of zero order; the complex
potential of that flow of zero order is proportional to the complex
velocity of the conical field given in the direction i, since the pro-
portionality factor is real.
The proof follows immediately. According to sections 1.1.2
and 1.1.3 one may be satisfied with considering, for definition of a
homogeneous flow, the inside of the cone (r); comparison of the for-
mulas (1.29), (I.30), (I.31), (1.32), (1.33) entails the validity of
the above theorem'if I is parallel or orthogonal to U. Hence the
general case where I is arbitrary may be deduced immediately; if
F(Z), G(Z), H(Z) are the complex velocities in projection on Oxl,
Ox2, Ox3, the expression for the component u of the field derived in
-4
the direction I(EE 2,3) is
u = p2 + 1 R Z F'(Z) + e20'(Z) + 3H'(Z)
u i 02 1 C
Thus, with E1F(Z) + E2G(Z) + E3H(Z) being the complex velocity in
projection on 1, comparison of this formula with the first formula (I.29)
completely demonstrates the theorem.
-4
Corollary: The field derived in the direction 2 of a conical flow,
the complex velocity of which in the direction I is K(Z), is a
velocity field of a homogeneous flow dependent only on K(Z) (not on
the direction I).
The theorem just demonstrated may be extended without difficulty
to the homogeneous flows of nth and (n-l)th order. A statement of this
general theorem would require only specification of a few definitions;
however, since we shall not have to utilize it later on, we shall not
formulate this statement.
NACA TM 1354
CHAPTER II CONICAL FLOWS WITH INFINITESIMAL CONE ANGLES *
2.1 Solution of the Problem
2.1.1 Generalities
We shall now treat the first problem set up in section 1.2.6. We
shall operate in the plane Z. Let us recall that the image of the
cone (r) is the circle (CO) of radius unity centered at the origin,
and that the image of the obstacle is a curve (C), defined by its polar
equation p(e). We shall denote by (D) the annular domain comprised
between (C) and (CO); we shall call (O0) the circle of smallest
radius centered at the origin and containing (A) in its interior, and
we shall call k the radius of the circle (70). In this entire
chapter, k will be considered as the principal infinitesimal.
The problem then consists in finding three functions U(Z), V(Z),
W(Z) defined inside of (D) except for an additive imaginary constant,
so that
(1)
-3 dU 2Z dV 2iZ dW (1.25)
Z2 + 1 Z2 1
(2) the real parts u, v, w, which are uniform become zero on (CO),
(3) on (C), one has the relation
vp cos e + p' sin 8 + p2(p cos e p' sin e) +
r -j 2
p sin e p' cos e + p2( sin 0 + p' cos e) = 2-2( + u)
Put in this manner, the problem is obviously very hard to solve in
its whole generality; however, an analysis of the permissible approxima-
tions will simplify it considerably.
2.1.2 Investigation of the Functions U(Z), V(Z), W(Z)
2.1.2.1.- An analytical function of Z will be the said func-
tion (A) if its real part becomes zero on (Co). Let us designate by
NACA editor's note: Some minor inconsistencies appear in the number
of equations in this chapter and subsequently in chapters III and IV, but
attempt was made to change the numbering as given in the original text.
NACA TM 1354
(70') the circle with the radius 1/k, centered at the origin, and by
(D') the annulus limited by (o0) and (70') (fig. 10).
Lemma I.- A uniform function (A), defined inside the annulus
limited by (70) and (CO) may be continued over the entire domain (D').
This results immediately from Schwartz' principle. Let M and M'
be two symmetrical points with respect to (Co), M being inside of
(CO); 6ne defines the function (A) at the point (M') as having,
respectively, an opposite real and an equal imaginary part compared to
the real and the imaginary part of the function given at the point M.
Lemma II.- A holomorphic function (A) inside of (D') has a
Laurent development of the form17
+ 2IQnn~izn
ip+ Z Kn)
1
Let H(Z) = h + ih' be such a function (A). Let us write its
Laurent development in (D') provisorily in the form
H(Z) = JnZn + -n
0 1
It is an immediate demonstration and yields the formulas defining Jn
and Kn
Kn = (h + ih')o7eind8
21t 0O
17
We remember that Kn denotes the conjugate imaginary of Kn.
NACA TM 1354
(h + ih')70 denoting the value of H on (70); likewise
J -kn 2
I230
(h + ih') ie-inede
(h~ih '70
Consequently, according to the lemma I:
Kn = -Jn
moreover
S2n
H(Z) d
Z 2xJo
S.2n
(h + ih')0 dO -
00 2n 0o
is purely imaginary, and the lemma II is therewith demonstrated.
We shall note that, if H(Z) is limited by M on (70)
one has the inequality
or (70'),
Kn < Mkn (II.]
Lemma III.- A function (A) with a real and uniform part defined
in (D) can be developed inside of (D') in the form
B log Z + ip + (f KnZn (II._
with B being real.
Actually, the derivative of the function (A) is necessarily uni-
form. Thus one knows (see for instance ref. 13) that one may consider
the given function as the sum of a uniform function H(Z) and a loga-
rithmic term; since the critical point of the logarithm is arbitrary
inside of (O), it is particularly indicated to choose this point at
the origin; since the real part of the function is uniform, the coeffi-
cient of log Z is real. Besides, since log Z has a real part zero
h d
Co
Jo i-
2i ,0
co
NACA TM 1354
on (Co), H(Z) is itself a function (A). The given function may
therefore be continued inside of (D') and the development (11.2) is
thus justified.
Remark.
(7o)
form
If one chooses as pole of the logarithmic term a point inside of
but different from the origin, one obtains a development of the
B' log aa -- + i8 +
1 1
- K'nZn
2.1.2.2.- The functions U,
three functions (A) with a real
be developed in the form (II.2).
- e u(z)
2
= A log Z + ia
V(Z) = B log Z + ip
W(Z) = C log Z iy
+
ixz
V, W of the variable Z are all
uniform part and, consequently, can
We shall write henceforward
(n JZ
Znn nZn)
J K n Zn
- n
- L,'n
Lnzn)
(11.3)
A, B, C are real, a, 0, ? are real and also arbitrary; but these
developments are not independent since the relations (I.25) must be
taken into account. For instance, Z dV/dZ must be divisible by Z2 + 1;
otherwise we would have for U logarithmic singularities on the cone (r)
=B-i
1
n(K"n + izZn
Zn|- + K, I
zd
dZ
(+ Ln
1
NACA TM 1354
Hence one deduces the relations
B 1= ( P[K2p + R2]
1
S=3 ( 1)P(p + 1)K2p
0
- Kp+1
obtained by putting in the preceding equality Z = i and
Z = -i.
Z dW/dZ must be divisible by Z2 1 which gives
C = 2p (L2p + L2p)
1
0 => (2p + 1)(L2p+1 + L2p+l)
0
connecting the coefficients of the developments (II.3)
thus one may write the relations
B + 2K2 =-i[C 2L2]
nKn (n 2)Kn2 =
to relationships
among themselves;
K1 K1 = -i + L]
i[(n 2)Ln-2 + nr]
(n >,2)
and on the other hand
B =-(J + J1
K1 = -A + 2J2
nKn = (n 1)Jn-1 +
Likewise,
(n >2)
(n + 1)Jn+1
NACA TM 1354
2.1.2.3. Approximations for the developments (II.3).- Moreover,
the hypotheses of linearization must be taken into account which, as we
shall see, will permit us to simplify the developments (11.3) consider-
ably and will lead us in a very simple manner to the solution of the
problem posed in section 2.1.1.
The qualities (11.6) make V(Z) and W(Z)
order. We shall denote by M an upper limit of
circle (70). M will be equally an upper limit
(70') and hence in the entire domain (D').
seem of the same
their modulus on the
of their modulus on
If one utilizes the inequality (1.1), (11.4) shows that18
B = 0 Mk2)
K1 1 = o(Mk2
If one assumes a, 0, 7 zero in what follows, which does not at
all impair the generality, one may write the second formula (11.3) in
the form
V(Z) R(Kn ( -
and consequently:
2
2
Kn = B log Z -
Zn
In the annulus limited by (70) and
equality is
o(Mk2log k)
Likewise according to equation (11.5)
C = o(Mk2)
(Co), the second term of this
L1 + i =o(Mk3)
W(Z) iT(L1)(. + Z) n = C log Z + RL)
2
- z)
- n
2
180 denotes Landau's symbol, A = 0 Mk2) signifies that A is
Mk2
limited when k tends toward zero.
nZn + iT(K1)(
+ z)
NACA TM 1354
In the annulus comprised between (70) and (CO), the second term
of this equality is also
S(Mk21og k)
Furthermore, according to equation (1.6)
Kn-2 + Ln-2 = 0 (kn)
(n > 2)
Thus
W(Z) iV(Z) = (Mk2log k) + 2iK1Z
in the annulus (70,C).
Finally, according to equation (11.7)
A = -K1 + o(Mkl3)
Jn = n 1 Knl + O n+2
n
Q U(Z) = -R(Kl)log Z 2K2Z + n + 1 Kn+ +1
2 -- n Zn
1
Summing up: If one is satisfied with defining V(Z)
for O(Mk2log k) and U(Z) except for O(Mk3log k),
the corona (o',Co)
O(Mk3log k)
and W(Z) except
one may write in
W(Z) = iV(Z) + 2iKiZ
V(z) = H(Z) K1Z
(11.8)
Thus
NACA TM 1354 37
with
H(Z) = Kn (II.10)
1
and
U(Z) = Z dZ 2K2 (II.11)
The coefficient K1 may be supposed to be real, and the integra-
tion occurring in equation (II.11) must be made in such a manner that
R[U(Z)] will be an infinitely small quantity of the third order at
least on II = 1.
2.1.2.4 Remarks.
(1) The formula (1.8) which is the most important may be estab-
lished immediately from the second formula (1.25). However, the method
followed in the text, even though a little lengthy, seems to us more
S natural; also, it shows more clearly the developments of the func-
tions U, V, W.
(2) Strictly speaking, the hypotheses set forth in the course of
this study must be verified by the solutions found in each particular
case. We shall, however, omit this verification which in the usual
cases is automatically satisfactory.
(3) The results obtained by the preceding analysis and condensed
in the formulas (II.8), (II.9), (II.11) are in all strictness valid only
in the annulus (o0'CO), but not in the domain (D). However, it is
very easy to extend, by analytical continuation, the definition of H
to (D). Let us now first suppose that (C) contains 0 in its
interior; since one may write V(Z) in the form
V(Z) = H(Z) Z KnZ + B log Z
1
one sees that, since V(Z) is defined by hypothesis in (D), and one
can extend KnZn and B log Z inside of (70) up to (C), H(Z)
1
NACA TM 1354
may itself be defined without difficulty inside of (D). The case where
(C) does not contain the origin offers no difficulty; it is then suffi-
cient to utilize the development given at the end of section 2.1.2.1.
As to the order of the terms neglected when one writes the equal-
ity (IT.9) in the domain (D), they are found to be O(Mk2log k) in
(D) in the case where there exists inside of (C) a circle of the
radius Xk (X and 1/k may be considered as 0(1)). Besides, if
that is not the case, one may justify the validity of the results of
the formulas (11.8), (II.9), (11.10), (II.11) by making a conformal
representation of the domain (D) on an annulus; the radius of the
image circle of (Co) may be assumed equal to unity; the image circle
of (C) has a radius infinitely small of first order with respect to
k and the study may be carried out in the new plane of complex variable
thus introduced, without essential complication.
2.1.3 Reduction of the Problem to a Hilbert Problem
If one puts, according to the formula (II.8)
V = v + iv'
with v' denoting the imaginary part of V, one may write on (C) the
relation
w = -v'
Since one may, of course, with the accepted approximations, neglect u
compared to 1 in the second term of the formula (1.28), one sees that
this boundary condition (1.28) affects now only one single analytical
function, the function V(Z); this is a first fundamental consequence
of the preceding study. Formula (II.9) shows that this condition con-
sists in posing a linear relation between the real and the imaginary
part of H(Z) on the obstacle. Now according to equation (II.10) the
function H(Z) is a holomorphic function outside of (C), regular at
infinity; the problem stated which initially referred to an annular
area (D) is thus reduced to a Hilbert problem for the function H
defined in a simply connected region; exactly speaking, one has to solve
an exterior Hilbert problem. This is the second fundamental consequence
of the results of section 2.1.2.
Since we attempt to calculate V(Z) and W(Z) not further than
within O(Mk2log k), and U(Z) within 0(Mk5log k), the relation (1.28)
NACA TM 1354
which is written
R (v iw)2Z2d0 i dz(l p2
may be simplified and reduced to
S- dZ(v iw) 2P d
[ ] 2
On (C),
and therefore
KiZ is, according to equation (II.1), of the order of Mk2,
H = V = v + iv' = v iw
consequently, H satisfies, on (C), the Hilbert condition
R iH(Z) dZ] 2p- d6
(11.12)
2.1.4 Solution of the Hilbert Problem
A function H(Z), holomorphic outside (C), regular and zero at
infinity, satisfying on (C) the relation (II.12) must be-found. Let
a1
z = Z + a+ +
S Z
(11.13)
be the conformal canonical representation of the outside of (C) on
the outside of a circle (7) centered at the origin of the plane z;
the adjective canonical simply signifies that z and Z are equivalent
at infinity.
On (7) we shall put
z = reil
S2p2 d
. -de
NACA TM 1354
r being constant and well determined. Let us put
F(Z) = i log z (II.14)
One has on (C) or on (7)
F'(Z) dZ = i dz = -dP = f(e) dO (II.15)
z
with f being real; consequently
d d F'(Z) d F'(Z)
P-- -,z =~ 4i
and therefore equation (II.12) is written
H(Z) p2
S2 (11.16)
l F'(Z) p dI
H(Z)/F'(Z) is a holomorphic function outside of (C) and regular at
infinity. Following a classical procedure, we thus have reduced the
Hilbert problem to an exterior problem of Dirichlet.
Let G(Z) be the holomorphip function outside of (C), real at
infinity; its real part assumes on (C) the values G(Z) is
0 dQP
determined in a unique manner. According to equation (II.12)
H(Z) = -iG(Z)F'(Z) + iEF'(Z) (11.17)
with c being a real constant.
However, we have seen (section 2.1.2.3) that the coefficient of 1/Z
in the development of H(Z) around the point at infinity (coeffi-
cient KI) was real; now, around the point at infinity
a
iF(Z) =- + +.
Z 2
NACA IT 1354 41
In order to have the development of the second term of the formula (11.17)
admit a real coefficient of 1/Z, E must be zero since G(Z) is real at
infinity. Thus the desired solution is
H(Z) = -iG(Z)F'(Z) (II.18)
With the function H(Z) thus determined, the formulas (11.8),
(11.9), (II.11) permit calculation of the complex velocities U(Z),
V(Z), W(Z) within the scope of the accepted approximations. Thus the
problem posed in section 2.1.1 is solved.
Remarks.
(1) Uniqueness of the solution.- The preceding reasoning shows the
solution of the Hilbert problem satisfying the conditions (II.16) to be
unique. This result will be valid for our problem if one shows that
every function satisfying the condition (II.16) is a solution of the
initially posed problem (condition (II.14)) which is immediate since it
suffices to repeat the calculation.
(2) Calculation of the coefficient K1.- According to what has been
said above, the coefficient K1 is equal to the (real) value assumed by
SG(Z) at infinity. In order to find G(Z), we may solve the Dirichlet
problem in the plane z; according to a classic result of the study of
harmonic functions, K1 is equal to the mean value of 2p2 O on the
circle (7). Hence
K1- = 2f 2p d d9P = i-f p2d = 2S
27 0 d dp PJ() Tr
wherein S represents the area inside the contour (C).
2.2 Applications
2.2.1 General Remark
Let us consider a cone of the apex 0 in the space (Oxl,x2,x3),
the image of which in the plane Z is the curve (C), defined by its
polar equation p(e). According to the definition of p (see the
remark of section 1.2.5) the sections of this cone made by planes par-
allel to Ox2x3 are homothetic to the curve
NACA TM 1354
x2 2p cos e x 2p sin 8 (II.19)
1+ p2 1 + p
In the case of the linear approximations, with grad u, grad v,
grad w being infinitely small (it would even be sufficient that they
should be limited), one sees that one may, within the scope of the
approximations of section 2.1, simplify the formulas (11.19) without
inconvenience and write them
x2 = 2p cos 6 x3 = 2p sin 0
hence the result, essential for the applications.
The curve (C) in the plane Z is homothetic to the sections of
the cone obstacle made by planes normal to the nondisturbed velocity.
Let us likewise consider a cone with variable but small incidences
so that the flow about the cone should always be a flow in accordance
with the hypotheses of this chapter. One sees that if the orientation
of the cone varies with respect to the wind, the curve (C) in the
plane Z undergoes a translation.
2.2.2 Study of a Cone of Variable Incidence
This last remark allows us to foresee that when a thorough investi-
gation of a cone has been made for a certain orientation with respect to
the velocity it will not be necessary to repeat all the work for any
other orientation. This we shall specify after having demonstrated the
following lemma.
2.2.2.1 Lemma.- One may write on (C) that
2P2 de 2 R Z dZ (II.20)
0P d r;, ~d (11.20)
P dT p dz
Actually, let us put
Z = p cos 0 + ip sin e = X + iY
X and Y may be considered as functions of :P.
42
NACA TM 1354
Hence one deduces that
Y
tan e =
X
de
cos2
Y'cpX X'rpY
X2--
x2
and consequently
2 p2 de = 2 Y' X X'rY) = 2 R
P a;P 134 p/
- i dZ 2 R dZ
d;' R dz
which establishes the formula (11.20).
2.2.2.2.- Let us now consider two contours (CO) and (C1) defined
in the plane Z by two functions Z(O)(-') and Z(1)(c) such that
Z(O) = Z(1) + a, a being a complex constant determining the change in
orientation. In the development (II.13) which gives the conformal repre-
sentation, only the coefficient a0 varies when one passes from the
contour (CO) to the contour (Cl). Consequently
,z (1)
dz
dZ(o)
dz
and the Dirichlet condition determining the function GC"'(z) is written
in the plane z
RE()z) =2 R z(l) z] L )z +- Raz
dz_ 0- dz] dz
(we have omitted superscripts for the quantities which retain the same
value, affected by the index 0 or 1). Consequently
G(1)(z) = G(0)(z) + [g(z)
since g(z) is a regular function and real at infinity, holomorphic out-
side of (7), the real part of which on (7) assumes the
NACA TM 1354
values R(az dZ/dz), g(z) is then very easily determined. One has
exactly
g(z) = z dZ + ar2
\dz / z
Thence for the function H(1)(z), (since
F'(Z) = i/z dz/dZ)
H(1)(z) = H(0)(z) + a dz + 2
0 \ dZ( -2 dZ
(11.21)
The formula (11.21) gives immediately the solution of the problem of
change in orientation with respect to the nondisturbed flow.
2.2.3 Cone of Revolution
We shall study first of all the case of the cone of zero incidence.
One may then do without the preceding analysis and obtain the solution
directly; that is what we shall do here. The curve (C) is a circle of
the radius p = cte = r; the relation (1.28) is written
2rO
v cos e + w sin 8 = 2ro
P(1 + r02
On the other hand, for reasons of symmetry
v sin 0 w cos e = O
Hence one deduces immediately the values of v
2r0 cos 0
S=
b0 1 r02
and w on (C)
2r0 sin 0
1 r02)
NACA TM 1354
whence
v(z) = 2ro 2 Z
3(1 -)- r
W(Z) = i 2ro 2
0 1 ro
+ )
(11.22)
Finally the relations (1.25) permit the calculation of U
- dU 2r02 2Z 11 + Z2 _
P(l r) Z2 +1 Z2
4 rO2 1
S1 ro4 z
2
U(Z) 4 r0 log Z
2 1 r4
(11.23)
We shall now study, returning to the method of section 2.1, the
case of a cone of revolution with incidence.
The formula (II.13) is written
z = Z a
a being a constant which may be supposed to be real.
Consequently
F'(Z) = i
On the other hand, an immediate calculation shows that
do r(r + a cos T)
dP p2
whence
NACA TM 1354
and consequently
whence
2p2 dO 2 (2 + r cos rP)
P d'P (\
G(Z) = (r2 + ar2)
P\ Z a
According to equation (11.18)
H(Z) = 2 + ar2 ) 1 2 r2 Z
\ Z aZ a p (z a)2
the calculation is easily accomplished; one finds
V(z) 2r2 Z 1
(Z a)2
U(Z) = 4 og(Z a)
02
3_a a2
Z a (Z a)2
K2 = +a r2
In particular, one finds, if a = 0, by means of the approximate
formulas (11.24) and (11.25), the same result as by the formulas (II.22)
and (II.23) under the condition of neglecting in these formulas the term
in r0 of the denominator.
In order to give to these formulas a directly applicable form it
suffices to again connect the quantities a, r with the geometrical
data; for this purpose, one must use the formula defining p (p. 42).
since
+ 4aZ
(11.25)
NACA 3T 1354
Figure 11 represents the cone section made by the aerodynamic plane
of symmetry; a is the semiangle at the apex, 7 denotes the angle of
the cone axis with the nondisturbed velocity.
One has immediately
2r = pa 2a = py
Finally, we shall utilize for the calculation of Cp the for-
mula (I.11) since the velocity component u is infinitely small com-
pared to the components v and w. This formula is here written
Cp = -2R[U(Z) V(Z) 2 (11.26)
According to equations (II.24) and (11.25) one has
C = 2a21og ~2 2 + 4ay cos 0 + 272cos 20 (II.27)
jp Pa
The case of the cone of revolution of zero incidence is obtained
by making 7 = 0. One finds then again a known result. The for-
mula (II.27) had already been given by Busemann (see ref. 9) without
demonstration.
2.2.4 Elliptic Cone
We assume first of all the simplest hypotheses where the
planes Oxlx2, Oxlx3 are symmetry planes of the flow (U is in the
direction of the cone axis), with the cone flattened out on Oxlx2.
The formula (II.13) may be written in the form
Z = z + a2
z
or
p cos 6 + ip sin = r + a2 cos 9 + ir a)sin 9
r r \
48
Hence one deduces successively
tan B = r2 a2 tan P
r2 + a2
Scos2 r2 a2
cos2m r2 + a2
NACA TM 1354
r2 a 1
r2)2
r
2 2 dO = 2/2 a
0 d' P r2
The Dirichlet problem, which permits calculation of G(Z), is
readily formulated; since G(Z) has a constant real part on the con-
tour (C), G(Z) is constant:
z2
F'(Z) = i 1
z z 2
whence
H(z) = r2
H(Z) 2
(r
_ a2 a2
z
aA 1
r2Z2 4a2
We note besides that
and
K2 = 0.
NACA TM 1354
One calculates V(Z) by the formula (II.9)
(14a
V(Z) = 2(r2 1 Z)
\ r2/ ^" j2_
and U(Z)
by the formula (II.11) which may also be written
U(Z) = H K G 2K2Z
0 1 z '
whence
U(z) = i2 r
p2\(
U(Z) 2
p2
lo z z2 a2
Z + Z2 4a2
2
If one makes a = O, one will find again the expressions already
obtained for U(Z) and V(Z) in the case of a cone of revolution of
zero incidence (formulas (II.24) and (II.25) in which one makes a = 0).
We shall denote by e and by Tj
elliptic cone (see fig. 12). One has
the principal angles of the
E3 = 2(r + a2
T = 2(r a)
whence
r = (E + r1)
4
(11.28)
(11.29)
or
(11.30)
- l
r 2
a2 =
16
(C2 2)
NACA TM 1354
The pressure distribution on the cone circumference is easily cal-
culated. It is sufficient to apply the formula (II.26); besides
IV(Z)2 = E2112
T2cos2p + E2sin2cp
R[U(Z]- = log C+ T
2 2sin2(2
r2cos2C + E2sin2rg
hence the final formula
- 1 +
The case where the velocity is
may be treated equally by utilizing
one must put
HO(z) = (2 a 1--
-< -
One then obtains
H(l)(z) = 2(r2
(r
r z2 a2
not in the direction of the axis
the formula (11.21). In this formula
dZ= 1 a2
a2 dz z2
z2
z2 a2
zr2 z2
z2 z2 a2
2 kr2 E- z + r2 a2]
P(z2 a2) k 2
hence, remarking that
a2
Z = z + -- + a
z
and
(11.31)
NACA TM 1354
H(Z) = 2 2 1
\ r T(Z )2 4a2
(ax2 a2(z a(- (Z -a)2 4a2
2a2 (Z a)2 a2
V(Z) = H(Z) jr2 Z
-2]
On the other hand, we shall calculate U by utilizing the vari-
able z and the formula (II.20). The coefficient K2 is equal to
K2 ( r2 a + r2 a 2a
and U(z) is then given by the formula
a4 og 2a2 + az
_ log z z
r2/ z2 a2
+ a2 2 (22 + a)
z(z2 a2)
One will note that, if
mula (11.30), and that, for
except for the notations.
one puts a = 0, one finds again the for-
a = 0, one finds again the formula (11.25),
Thus one can, without any difficulty other than the lengthy writing
expenditure, calculate the pressure distribution coefficient on the
elliptic cone of any arbitrary orientation with respect to the wind.
U(z) =- 4 (r2
P2
K2
+4 -Z
p
(11.32)
52 NACA TM 1354
2.2.5 Calculation of the Total Forces
We have already seen in section 1.2.6 that the normal to the conical
obstacle directed toward the outside has as direction parameters
i(x3x2' x2x'), x3', -x2'
Let n be the unit vector coincidental with this normal, s be
the area of the section with the abscissa xl, L the length of this
section; one may make correspond to the resultant of the forces acting
on a section (x4, xl + dxl) a dimensionlesss) vector
Cz = C pn ds (11.33)
situated in the plane x2x3, and a dimensionless number
C 1 Cp(nU)ds (11.34)
the vector Cz characterizes the lift, the number C, the drag.
The integrals appearing in the formulas (33) and (34) are taken
along the section. Naturally Cz and Cx are independent of this
section. One may also replace C by a complex number Cz, the real
and iaginary parts of which are equal to the components of the vec-
tor C on Ox2 and Ox3. For calculating equations (11.33) and (1.34
one may utilize the section xl = 8. If we assume I to be the length
of the contour (C) in the plane Z, we may write, taking into account
the habitual approximations
Cz Cp dZ (11.35)
and
Cx [i CpZ dZ (I.36)
51 JC J
NACA TM 1354
with the integrals appearing in equations (11.35) and (11.36) taken in
the plane Z. These integrals present a certain analogy to the Blasius
integrals (ref. 13); Cp is given by the formula (II.26); unfortunately,
it is not possible to give simple formulas for the total forces since
the integrals (11.35) and (11.36) make use of all coefficients of the
conformal representation19.
We shall apply
circular cone; Cp
the formulas (11.35) and (11.36) to the case of the
is given by equation (11.27)
dZ = i fB eide
2
Z dZ = i 24- de
4
2 = xSp
One obtains
C, = -2ay
In the case of the elliptic cone of zero incidence, Cz
ously zero
- -i- a2 eiP
Z = re-i+P + e-
r
Cx = 2( r2
0P
Cx= 2a31og 2- 3 My2
OM
(11.37)
is obvi-
ireicP a2 iPj
dZ = i e e- doP
r
- 21 Cp dCP
Z^O p
being given by formula (II.31). Now
ScrT dP =
2(Tl2cos2% + e2sin 2 )
+ E dt
Do T2 + E2t2
19See appendix No. 7.
whence
with Cp
54 NACA TM 1354
As one can see immediately by putting
t = tan CP
the calculation of this last integral is immediate.
Thus one obtains
c = 2 2l g (E + n) 2 (11.38)
with 2 being the length of the ellipse with the semiaxes C-, -.
2 2
2.2.6 Approximate Formula for the Calculation of Cx
Let us consider the function U(z); according to formula (II.11)
and the remark 2 of section 2.1.4 one may say that the principal term
for U(z) is
U(z) = 4 Si log z
rp2
Consequently, in first approximation
8s
C S log r
with S being the area inside of the contour (C), and r the radius
of the circle (7) on which one makes the conformal canonical repre-
sentation of (C). If one now calculates Cx, taking into account this
approximate formula, one has, according to equation (11.36)
C 1S log rR i dZ
whence
C, =+ 32S2 log_ (II.39)
itp3" r
NACA TM 1354
We shall state: In every first approximation the value of the
drag coefficient C, is given by the formula (II.39).
2.2.7 Case Where the Cone PresenLs
an Exterior Generatrix
If the contour (C) shows an exterior angular point, the various
functions introduced in the course of the study (first paragraph of
this chapter) present certain singularities. These singularities we
shall specify. Let ZO be the designation angular point of (C), and
B6 the angle of the two semitangents to (C) at the point Z0(O < 6 < 1)
(see fig. 13); if- z0 is the image of the point Z0 in the plane z,
one may write, according to a well-known result, in the neighborhood
of zO
(LdZ\ K= z zo)k
\dz10
with K being a complex constant and k = 1 8; consequently
k
F'(Z)0 = K1z -0 = 2 (Z ZO 1+k
with K1 and K2 being complex constants. F'(Z) thus becomes infinite
at the point Z = Z0.
In contrast, the function G(z) has, according to definition, a
real part which assumes on the circle (7) the values
RzZ -]
This real part thus remains finite on the circle (7) (and it
satisfies there a condition of Holder). According to a known theorem,
Sits imaginary part likewise remains continuous on (7) (and likewise
Satisfies a condition of Holder). Consequently, one sees, if one refers
Sto formula (11.18) that
56 NACA TM 1354
k
H(Z) = K3(Z ZO) l+k
in the neighborhood of ZO; likewise, U, V, W will, in the proximity
of this point, be of the order k with respect to 1
1 + k Z- Z
Thus the analysis made in section 2.1 is no longer applicable to
this case. However, the formulas (11.35) and (II.36) show that if the
pressure coefficient assumes very high values in the neighborhood of
Z = ZO, the total energy remains finite. According to what we have
indicated in section 1.1.3 we consider the solution still valid, with
the understanding that the values of Cp in the surroundings of Z = ZO
are not reliable.
2.2.8 Delta (A) Wing of Small Apex Angle
at an Infinitely Small Incidence
If one puts in the formulas r2 = a2, at the end of section 2.2.4,
one obtains the pressure distribution on a delta wing with small apex
angle. Let us recall that a delta wing is an infinitely small angle.
Its angle, according to definition, is the half-angle w at the vertex
(compare fig. 14). Thus one has
op = 4a
The formulas (11.31) and (11.32) are applicable to a delta wing of
small angle placed at an incidence also rather small.
Let us moreover assume that this opening is infinitely small with
respect to the incidence. Under these conditions, the formulas yielding
U(Z) and V(Z) are written
V(Z) 2 a a Z 42 42
P2 2 4z2 4a2
2 2
U(Z) 4 a 4a + 8a (a a)Z (11.40)
82 2 JZ2 _4a2 02
NACA TM 1354
Actually one is justified in omitting the second-order terms with
respect to a. For calculating Cp it suffices to apply the for-
mula (11.8); the second term of the second formula (II.40) may be
neglected.
With the incidence 7, the delta wing being parallel to
70 = 2ia
Finally, one may put along the A
Z = 2a cos q = R cos (P
2
One then finds
c = 2'uy
C s-in
S sin
Ox2, one has
We remark further that p is related to the angle
213 = mP cos i
I of figure 14
W = n cos
2
One may state: the pressure coefficient on a delta wing of infi-
nitely small opening angle is independent of the Mach number of the flow.
One has
Cp = 2 if 2i
S-_ 2 tu
uI t
if one applies formula (11.35), one finds
Cz = inay
This coefficient Cz has not the same significance as the one
utilized in the theory of the lifting wing. Actually, it is, according
(11.41)
58 NACA TM 1354
to the very manner in which it was obtained, relative to the total area
of the A (pressure side and suction side); if one takes only one of
these areas into account, one must write (neglecting the factor -i)
Cz = 2nwu
This formula has been found by other methods by R. T. Jones
(ref. 14). We shall find it again in chapter III, section 5.1.2.4, when
studying the general problem of the delta wing which is here only touched
on incidentally and for the particular case of a A with infinitely
small opening angle.
2.2.9 Study of a Cone With Semicircular Section
As the last application, we shall treat the case of a cone with
.--
semicircular section, with the velocity U being directed along the
intersection of the symmetry plane and of the face plane of the cone20
(fig. 15).
The contour (C) in the plane Z then is a semicircle, centered
at the origin, of the radius a (fig. 16).
One obtains very easily the conformal canonical representation of
the exterior of this contour, on the outside of a circle (7) of the
radius r, centered at the origin of the plane z, by means of a par-
ticular Karman-Trefftz transformation (ref. 13, p. 128) which is written
-i 2
S6
Z a z re (11.42)
Z + a 5n
-1-i
z re
a and r are connected by the relationship
4a = 3r41
In order to obtain the correspondence between the circle (7) and
the contour (C), one must distinguish two cases. Let us put
z = re
20Such a cone formed the front of supersonic models planned by
German engineers.
NACA TM 1354
(1) < 6 < the corresponding point of
of the circle.
Let us put under these conditions
Z = aeir
and we shall find according to formula (II.42):
(C) is on the arc
tan -
2
(11.43)
(2) 7 < p < n, the
6 0
ment AA'; let us put under
corresponding point of
these conditions
(C) is on the seg-
Z = a cos .
The formula (11.42) shows that
r4
tan -
2 P 5t
tsin( + 12
sin(+ j
(II.44)
The two last formulas define completely the desired conformal
representation. Figures (17) and (18) give the variations of and x
as functions of P.
We shall have to utilize equally the value of dz/dZ. The simplest
method for obtaining this value consists in logarithmic differentiation
of the two terms of formula (II.42). One thus obtains the result
dz z2 + rz r2
dZ 2 2
Z -r
(I1.45)
NACA TM 1354
If one has
- < ( < 6 6
z = rei
Z = aei-
whence
dz r2 1 + 2 sin q ei('-A) 8 1 + 2 sin 'P ei((P-)
dZ 2a2 sin 27 sin *
71r 117
If 'p is comprised between -- and --, one puts
b b
Z = a cos X. Thus one obtains
i(E --A
dz 16 1 + 2 sin r e2 )
dZ 27 sin2X
The function G(Z)
has as its real
part R zZ ]d that is
[- d~dz
2 ar sin 4
8 1 + 2 sin T
0
if <'JP <
6 6
if 6 < < 1
b o
The analytic function
a2 z dZ
Z dz
has a real part which, on (b), assumes these same values. This func-
tion is regular at infinity, holomorphic outside of (7), but with a
pole z = -i, with the corresponding residue being equal to -ia2
pole z = -ir, with the corresponding residue being equal to -ia
(11.46)
z = re ,
(1.47)
(II.48)
NACA HM 1354 61
Let us then consider the function
a2/2 dZ 1 z ir\
\Z dz 2 z + ir)
This function is holomorphic outside of (7). It is regular at
infinity; its value at infinity is equal to a2/2. On (7), these real
and imaginary parts satisfy Holder conditions. This function is there-
fore identical with the desired function G(z).
Hence one deduces according to equation (II.18)
and ac
t:
H(Z) ( r\a2 dz
Z dz 2 z + ir/ z dZ
cording to equation (II.19)
V(Z) = a2l Z 1
\Z 2 2z
Finally, the calculation of U(Z)
of formula (II.29)
G dz = a2log Z a z ir dz
2 jz + ir z
and
ZH a2/ 1 Z dz z ir
ZH2 z dZ z +
2 z dZ z + ir
Sa2 a2 z ir dz
Z 2z z + ir dZ
z ir dz\
z + ir dZj
may be carried out with the aid
= a2 (log Z + .1 log z)
\ z + ir 2 /
S= a2 z ir Z dz\
2) 2 z + ir z dZ/
whence
U(Z) = a2 ir Z dz 1 + + 2 log Z + log
\z + ir z dZ g2 z + ir
The calculation of the coefficients K2 offers no difficulty
does not occur in the calculation of the pressures along the cone.
n
i;
ii
i;
iii
,i
II
tl;
,ii
,,
,;
what-
K2
62 NACA TM 1354
This pressure distribution along the cone calculated with the aid
of equation (II.26) is represented in figure 19.
2.3 Numerical Calculation of Conical Flows With
Infinitesimal Cone Angles
2.3.1 General Remarks
In the preceding paragraph, we have studied a certain number of
particularly simple cases. However, if the cone (C) is arbitrary, it
will be necessary to carry out various operations leading to the solu-
tion by purely numerical procedures.
Let us analyze the various operations necessary for the calculation:
(1) The conformal canonical representation of the exterior of (C)
on the outside of the circle (?) must be made; this calculation per-
mits, in particular, determination of the radius r of (7), corre-
spondence of the points of (C) and of (7), and calculation of the
expression dZ on the contour (7).
(2) The function G(z), holomorphic outside of (7), regular and
real at infinity must be determined, the real part on (7) of which is
known; we shall designate it by g('). In fact, it suffices to know,
on (7), only the imaginary part of G(z), for instance g'('P); g'(P)
is the conjugate function of g(T) and is given by the formula
g'() =_ 1 g( ')cot P- dc'
2n Jo 2
This formula is called "Poisson's integral."
(3) With these two operations accomplished, the values of H(z) on
the circle (7) (formula (11.18)) are known which provides the values
of v and w on the cone; u is obtained by the formula (11.29). The
only new calculation to be made is that of the expression:
[B- f dz I drP
the constant of integration being determined so that u should have a
mean value zero on (M).
MACA 9M 1354
All these operations always amount to the following numerical
problems:
(a) With a function given, to calculate its conjugate function
(Poisson integral)
(b) With a function prescribed, to calculate the derivative of the
conjugated function
(c) With a function prescribed, to calculate its derivative21.
We shall justify this result in the following paragraph by showing
that the operation (1) may be performed by applying the calculations (a),
(b), (c). We shall then indicate a general method, relatively simple
and accurate, which permits solution of these problems. We shall ter-
minate this chapter by giving an application.
2.3.2 Conformal Canonical Representation
of a Contour (C) on a Circle (y)
The numerical problem of determination of the conformal canonical
representation of a contour (C) on a circle (y) has been solved for
the first time by Theodorsen22. We shall briefly summarize the principle
of this method, simplifying, however, the initial expos of that author.
Let us suppose, first of all, that the contour (C) is neighboring
on a circle of the radius a, centered at the origin (fig. O0); in a
more accurate manner, putting on (C)
Z = ae+ie (11.49)
with being a function of e, 0 = 4(e), we shall suppose that *(e)
and d- are functions which assume small values. We shall then call
de
21If the conformal representation of the exterior of (C) on the
outside of (7) is known in explicit form, it will naturally be suffi-
cient to apply operation (a).
22Compare references 15 and 16. One may achieve this conformal
representation also by the elegant method of electrical analogies (ref. 17);
the time expenditure required by the experimental method and by the purely
numerical methods here described as well as the accuracy of these pro-
cedures are of the same order of magnitude.
NACA TM 1354
(C) "quasicircular." Let Q be the angular abscissa of the point of
(7) which corresponds to the point of (C), the polar angle of which
is 0; we put
e = P + c((p)
cP = 0 E(0)
e(e) and E(cp) representing the same function but expressed as a
function of 0 or as a function of qP; we shall put likewise
(CP) = J1(e)
The desired conformal transformation may be written
Z zeh(z)
with h(z) being a holomorphic function outside of (7), regular and
zero at infinity. The equality (II.50) becomes, if one writes it on the
circle (7),
ae())+i T +(' = reiqeh(z)
whence
h(z) = W(~() + iE(cp) + log
r r
(11.51)
Finding the conformal representation of (C) on (T) amounts to cal-
culating the functions (cp) and T(p). First of all, one knows (equa-
tion of (C)) that
(11.52)
(p) = + C(r4) )
On the other hand, according to equation (II.51), e((P)
gate function of (cp), and consequently
is the conju-
-)=(<'P)cot(' 2 (
N(c') ot M P'
k 2
(11.50)
e(') 1 '
2x p n
2v
(II.53)
NACA TM 1354
the integral being taken at its principal value. There is no constant
to add to the second term of equation (11.53), for i(P) has a mean
value zero since h(z) is zero at infinity. For the same reason, if
*0 denotes the mean value of T('o) in an interval of the amplitude 21
r = ae'0
(11.54)
an equality which will permit calculation of r if T(P) is known.
In order to calculate T(P) and T(P), one disposes therefore of the
relations (11.52) and (11.53); one can solve this system by a procedure
of successive approximations.
We shall put first
o(e) = T0() = o
According to equation (11.52)
4(e) = on(0)
and according to equation (11.53)
l(e) = 1
'(S')cot d' e de'
2
Thence a first approximation for 7'
1 = a l(e)
S=' 1 + 1 )
From it one deduces, according to equation (II.52), a first approxima-
tion for Tl(c')
11 1 +
whence a second approximation for the function E
NACA TM 1354
r2 1 02n 1 1cot 1' 2p1
1 = j*2y W (c1)cot %i l ,P
2a 2 2 T
2(e) = c2 [e e1()]
whence
2 = a E(e) e = 2 + 2n
The procedure can be followed indefinitely.
The convergence of the successive approximations forms the subject
of a memorandum by S. E. Warschawski (ref. 18). We refer the reader
who wants to go more deeply into that question to this meritorious
report.
From the practical point of view one may say that the convergence
is very rapid; two approximations suffice very amply in the majority of
cases; the different changes in variables which encumber the preceding
expose are very easily made by graphic method. Thus one sees that the
numerical work essentially consists in calculating twice the inte-
gral (II.53). This calculation is precisely the object of the prob-
lem (a) stated at the end of section 2.3.1.
If the contour (C) is not "quasicircular," one may make, first
of all, a conformal representation which transforms it into the "quasi-
circular" contour (C'); one will then apply the preceding analysis to
the contour (C'). For certain cases it will be quicker to use a direct
method. Let us assume, for instance, that (C) is a contour flattened
on the axis of the X (compare fig. 21) and for simplification that
X'OX is permissible as the axis of symmetry.
Let us suppose that X varies along (C) from -a to +a while
IY| remains bounded by ma (with m being, for instance, of the order
of 1/10); it will then be indicated to operate as follows:
We put along (y).
Z = [f(rP) + ig(
SNACA TM 1354
One has
or also
X('C) = f cos CP g sin r
Y(P) = f sin p + g cos r
f = X cos r + Y sin m
g = Y cos '" X sin cP
f(P) is an even function of r,, g(C') is an odd function
f(0) = +f(n) = a
g(O) = g(n) = 0
The functions X(T) and Y(0) have to be found. Let us take as
starting point
XO(0) = a cos P
an approximation which would be definitive if (C) were an ellipse.
On the contour (C) one reads the corresponding value YO('P), and
by means of the second formula (II.56) one obtains a first approximation
gl(+) = YO(cp)cos rp Xo(p)sin (p
fl(q) will be given by a Poisson integral
2xi
0
gl(r)cot -'- "- dT' + X1
2
with X1 being a constant, such as fl(O) = a.
Owing to the formulas (II.55), one has a first approximation Xl('),
Y1(T) for the functions X(), Y('P). One proceeds in the same manner,
reading off on (C) the functions Y1(mP) corresponding to Xl('), then
(11.55)
(I1.56)
NACA I 1354
calculating
g2 1) = Yl(c)cos (p Xl(p)sin C
and
n')
=f
g2( p')cot P' dTP' + X2
2
When one
approximation
tions; then
has obtained a pair fn(P), gn(') providing a sufficient
Xn(), Yn(p) of X(C'), Y('), one stops the calcula-
r = X
In practice23 it suffices to take
of very slight adaptations) will apply
being flattened on OX, will no longer
axis.
n = 2; the same method (averaging
to the case where (C), although
admit of OX as the symmetry
Finally, for a complete solution of the problem (1) posed at the
beginning of the preceding paragraph, only dZ/dz remains to be calcu-
lated, which will obviously be possible with the aid of the problems (b)
or (c).
2.3.3 Calculation of the Trigonometric Operators24
The method we shall summarize permits calculation of the linear
operators A, transforming a function P(e) into a function Q(e)
23The principle of this method is the one we applied for the study
of profiles in an incompressible fluid. But in the case of the profiles
a few complications (which can, however, easily be eliminated) arise due
to the fact of the "tip."
24We gave the principle of this method for the first time in
March 1945 (ref. 19). Compare also reference 20. In continuation of
this report, M. Watson provided a demonstration of the formulas which
we obtained by a different method (ref. 21). We also point out a "War-
time Report" of Irven Naiman, of September 1945, proposing this same
method of calculation for the Poisson integral (ref. 22).
etc.
NACA TM 1354 69
Q(e) = A[P(e)
and re-entering one or the other of the following categories:
First category: The operator possesses the following properties
A(cos me) = am sin me
A(sin me) = -a cos me (II.57)
A(1) = 0
with am being a nonzero constant, m any arbitrary integral different
from zero.
Second category: A possesses the properties
A(cos me) = bm cos me
SA(sin me) = bm sin me
A(1) = bO
with bm being a nonzero constant, m any arbitrary integral.
We shall call these operators trigonometricc operators." The
operations which form the subject of the problems (a), (b), (c) are,
precisely, particular cases of trigonometricc operators."
With the function P(e) known, one now has to calculate the func-
tion Q(e); the functions P(e) and Q(e) are assumed as periodic, of
the period 2v. P(e) and Q(8) are determined approximately by knowl-
edge of their values for 2n particular values of 8, uniformly dis-
tributed in the interval 0, 2n. One knows that the unknown 2n values
of Q are linear functions of the known 2n values of P. The entire
problem consists in calculating the coefficients of these linear equa-
tions. We shall do this, examining two possible modes of calculation.
NACA IM 1354
2.3.3.1 First mode of calculation.- After having divided the
circle into 2n equal parts, we shall put
f= f
(1) Operators of the first category.- Obvious considerations of
parity show that the Qi are expressed as functions of the Pj by
equations of the form
n-1
i = KpPip i-p)
1
(11.58)
We shall apply the
equations (11.58)
relations (II.57), that is, carry into the
P(8) = cos me
P(O) = sin me
We thus obtain 4n
equation
Q(e) = am sin me
Q(e) = -am cos me
equations which are all reduced to the unique
n-l
SKp sin p m -a
1
(I1.59)
This reduction is the explanation for the success of the method.
We have to determine (n 1) unknown Kp. For this purpose, we shall
write the equation (II.59), for the values of p varying from 1 to
n 1. The system remains to be solved. If one multiplies the first
2!, scn b2 i)th
equation by sin -E, the second by sin L, the (n 1 by
n n
sin(n 1)n, and if one adds term by term, one obtains a linear rela-
tion between the Kp, with the following coefficients of Kp
NACA IM 1354 71
n-1 n-1
Wpn 1 (-nIP Jfn (p + [Jn
sin m sin m -- Co cos m
n n 2 5 n 1 nn
m=l m=l
1 Sn P Cn[ P( + )_n'
= 2 E D n In]J
with
n-1 ( sin x
Cn(x) = cos mx = cos x
2 x
m=O sin
Thus the coefficient of Kp is zero if p / n, and equal to if
2
p= U-
Thence the desired value of Kp
n-l
Kp = a sin m (pI.60)
m=l
Let us apply this result to the calculation of the Poisson integral.
This integral defines an operator Q = A(P) of the first category
for which am = -1.
Consequently, the formula (II.60) is written
n-1
Kp = : sin m = Sn
mn n n (
1
if one puts
n-1 sin nx
n- (n 1)x s 2
Sn(x) = V sin mx = sin -2 l)x
1 sin 2
1 2
NACA TM 1354
Thus
K = 0 if p even
(II1.61)
1 cot pA if p odd
KP n 2n
(2) Operators of the second category.- The considerations of parity
permit one to write the general formula
n-1
Qi = KOPi + (Pi+p + Pi-p) + Kni+n (11.62)
1
Using the same reasoning as before, one is led to determine the coeffi-
cients Kp by the system
n-1
KO + > 2Kp cos m E + ( 1)% = b (11.63)
p=l
with m assuming the values 0, 1, 2, n.
Multiplying the first value by 1/2, the second by cos pu/n, the
third by cos 2?, the nth by cos (n 1)p! and the last by ( )2
n n
and adding them, one obtains a linear relation between the Kp, with the
coefficient of Kp being (p / 0, p / n)
2 + )P+LL n ] + Cn(P- ) 2
that is, n if u = p, and 0 if p.
The coefficient of K0 is
2 2 2 + Cn n
NACA TM 1354
The preceding conclusions remain valid, it is zero for i J 0 and equal
to n if P = 0; the same result is valid for Kn. Finally, one
obtains the general formula of solution
(I..64)
Let us consider, for instance, the operator transforming the func-
tion- P(G) into the function dQ/de, with Q being the conjugate func-
tion of P; it is an operator of the second category for which
bm = -m
Applying formula (11.64), one obtains
KO m
2
n- n
_1
If one notes that
1n
n-l
(x) = m cos mx
0
12 sin n
2 sin2 x
2
one sees that
Kp = 0
1
n cos
n
if p even
if p odd
- 1)P
p / 0
- x sin2 x
2)
74 NACA TM 1354
2.3.3.2 Second mode of calculation.- Examination of an important
particular case will show us that in certain cases it will be advantageous
to consider a second mode of calculation.
The method consists in replacing the function P(e) by a function
of the form
n
D(e) = an cos nO + bn sin nO (11.66)
0
for which the method is applied with the strictest exactness; the con-
stants an and .bn are such that Pi = \$i. One operator of the first
category, one of the most important ones, is the operator of derivation
which makes the function dP/de correspond to the function P(O). If
we apply the first type of calculation, we shall replace ( -) by
\de/i
d(I ; now, it is precisely at the points 8 = in that the deriva-
(dei n
tives and show the greatest deviation. In contrast, we shall
de de
obtain a good approximation of the desired function by replacing
dP (2i + 1)n b d' (2i + 1)t
dO 2n dO 2n
We are thus led to the following mode of calculation: the circle
is divided into 4n equal parts; we shall put
fi = f(il)
\2n/
and we shall express the 2n values Q2i as a function of the 2n value
2j+l"
We shall limit ourselves to the operators of the first category.
The formula expressing the Q2i as a function of P2j+l is written
n
>2i =_ K(P2i+2p-l 2i-2p+l)
p=l
N ACA TM 1354
and we obtain for determination of the Kp the system
Ssin (2p l)m am
l 2n 2
p=l
with m varying from 1 to n.
Multiplying the first equation by sin(2P 1)--, the second by
2n
(20 l)2n th
sin( 1)2, .,the (n 1)th
2n
by sin (2P l)(n 1)n
by sin the
2n
(- 1
last by and adding them, one obtains a linear relation in
2
which the coefficient of Kp is
n-1
Z sin(2p -
m=l
1)mL sin(2p -
2n
n-1
>- cos(p u)L cos(p
1
+.- I )B + + C )P-P
"J 2
S ipn n-p + [L 1) + ( 1)
The coefficient is zero if p 6 I, and equal to E if
2
sin (2p l)mn
sin
2n
( 1)-1
2
p = P. Hence
(11.67)
This procedure may be applied to the calculation of the derivative
of a periodic function. In this case, am = -m. Applying formula (II.67),
one obtains
)n ( 1)P+P
2n 2
NACA IM 1354
Kp= ( 1)P-1 1 (1.68)
[ (2p l)xl
2n 1 cos ( n)
11 2n
2.-.3.4 Remarks on the Employment of the Suggested Methods.- In
order to convey some idea of the accuracy of the proposed methods we
shall give first of all a few examples where the desired results are
theoretically known.
Let us take as the pair of functions P(O), Q(e), the functions
p(e) = 4 cos 20 4 cos 9 + 1 Q(e) -4 sin 0(2 cos 0 1)
(5 4 cos 8)2 (5 4 cos 8)2
which are the real and imaginary parts, respectively, on the circle of
f(z) 1 (z = ei)
(2z 1)2
One will find in figure 22 the graphic representation of the func-
tions P(8), Q(e) and of the derivative Q'(0) of this function, and
also the values of these functions for e = p- (with p ranging
12
between 0 and 12). Furthermore, one will find in figure 23 the values
of Q(6), calculated from P(e) as starting point, by the method just
explained (coefficients Kp, defined by equation (II.61)), and in fig-
ure 24 on one hand the values of Q'(8), calculated from P(e) as
starting point (from coefficients Kp defined by equation (II.65)),
and, on the other, these same values calculated from Q(S) as starting
point (coefficients Kp defined by equation (11.68)). One will see
that the accuracy obtained is excellent although the selected functions
show rather rapid variations. Such calculations by means of customary
calculation methods are a delicate matter; this is particularly obvious
in the case of the Poisson integral which is an integral "of principal
value." Systematic comparisons of the method of trigonometric operators
with those used so far have been made by M. Thwaites (ref. 23); they
have shown that this method gives, in certain calculations, an accuracy
largely superior to any attained before.
The calculation procedure, with the aid of tables like the one
represented (fig. 25) is very easy. One sees that one fills out this
NACA IM 1354 77
table parallel to the main diagonal of the table. With such a table,
about one and a half hours suffice for a Poisson integral if one has a
calculating machine at his disposal.
We have had occasion to point out that the accuracy of the method
obviously increases to the same degree as the functions one operates
with are "regular" and present "rather slight" variations. This leads
in practice to two remarks which are based on the "difference method"
and reasonably improve the result in certain cases. We shall, for
instance, discuss the case of the Poisson integral.
(1) If the function P(G) presents singularities (for instance
discontinuities of the derivative for certain values of 0), it will be
of interest to seek a function P1(O), presenting the same singularities
as the function P(e), for which one knows explicitly the conjugate
function Ql(6). One will make the calculation by means of the func-
tion P(O) P1(0); this function no longer presents a singularity.
(2) If the function P(O) has a very extended range of variations,
one will seek a function Pl(8) for which one knows explicitly the
function Q%(8) so that the difference P(G) P1(0) remains of small
value, and one will operate with this difference.
Finally we note that, if the calculation of the derivative of a
function P(e) as described above necessitates that P(O) be periodic,
method."
2.3.4 Example: Numerical Calculation of a
As an application, we have taken up again the case of the semicir-
cular cone studied in section 2.2.9. The function g(1) is given by
the formula (II.48), and g'(Q) will be calculated by a Poisson inte-
gral. Figure 26 shows the value g'(c) thus calculated compared to the
theoretical value.
25We wanted to test the accuracy of the proposed method by assuming
an extremely unfavorable case, without taking into account the singu-
larities presented by the function g(T). For a numerical operation of
great exactness, this particular case would have required application
of the lemma of Schwartz, with the contour (C) completed symmetrically
with respect to OX.
78 NACA TM 1354
It is then possible to calculate the representation of the pres-
sures, by calculating successively the function H, ZH, and the inte-
gral g' (p).
One will find the pressure distribution thus calculated in fig-
ure 19; one may then compare the result obtained by the calculation
method (for a very unfavorable case) with the result obtained
theoretically.
NACA TM 1354
CHAPTER III CONICAL FLOWS INFINITELY FLATTENED
IN ONE DIRECTION
The purpose of this chapter will be the study of conical flows of
the second type (see chapter I, section 1.2.6). Before starting this
study proper, we shall make a few remarks concerning the boundary con-
ditions. The conical obstacle is flattened in the direction Oxlx2.
Under these conditions, reassuming the formula (1.27)
x2 vx3' = (xx2' x2x3') (1 + u) (1.27)
one may say that it reduces itself, in first approximation, to
w2' = x2x3') (III.)
since x3, x ', v, u are infinitesimals of first order, while x2
and x2' are not infinitesimals. Under these conditions, one may say
that one knows the function w on the contour (C). On the other hand,
one may write, within the scope of the approximations made, this boundary
condition on the surface (d) of the plane Oxlx2, projection of the
cone obstacle on the plane. Let us designate, provisionally, the
value w by w(1)( 1x2x3) if one operates as follows
(1)
w(l) J1x=t),(tx(t = w(l)E1,x2Ct)J] + xj(t) xx,2(t,
With the derivatives of w being, by hypothesis, supposed to be of
first order, and the boundary equation written with neglect of the terms
of second order, the intended simplification is justified.
Various cases may arise, according to whether the cone obstacle is
entirely comprised inside the Mach cone (fig. 27), whether it entirely
bisects the Mach cone (fig. 28), whether the entire obstacle is com-
pletely outside the Mach cone (fig. 29), or whether it is partly inside
and partly outside the Mach cone (fig. 30). In each of these cases
there are two elementary problems, the solution of which is particularly
NACA TM 1354
interesting: the first, where the relation (III.1) is reduced to
w = constant = w0
which we shall call the elementary lifting problem (the corresponding
flow is the flow about a delta wing placed at a certain incidence); the
second, where the relation (III.1) is reduced to
w = wO for x3 = +0
w = -wO for x3 = -0
which we shall call the elementary symmetrical problem. This is the
case of, for instance, the flow about a body consisting essentially of
two delta wings, symmetrical with respect to Oxlx2 and forming an
infinitely small angle with this plane. It is also the case that will
be obtained, the section of which, produced by a plane parallel to Ox2xy,
would be an infinitely flattened rhombus. The fact that one obtains the
same mathematical formulation for two different cases indicates the
relative character of the results which will be obtained. In the case
of the symmetrical problem one may naturally assume that w is zero on
the plane' Oxlx2 at every point situated outside of (d).
Let us finally point out that very frequently the obtained results
do not satisfy the conditions of linearized flows; in particular, the
velocity components and their derivatives will frequently be infinite
along the semi-infinite lines bounding the area (d). However, we admit
once more that the results obtained provide a first approximation of the
problem posed above, in accordance with the remarks made in section 1.1.3
of chapter I.
3.1 Cone Obstacle Entirely Inside the Mach Cone
3.1.1 Study of the Elementary Problems
The case of the lifting cone has already formed the subject of a
memorandum by Stewart (ref. 10); however, the demonstration we are going
to give is more elementary and will permit us to treat simultaneously
the lifting and the symmetrical case.
NACA TM 1354 81
3.1.1.1 Definition of the function F(Z).- We shall make our
study in the plane Z. Let A'A(-a,+a) be the image of the cut of the
surface (d)26, (Co), as usual, the circle of radius 1 (fig. 31).
Naturally, we shall operate with the function W(Z). One of the
conditions to be realized which we shall find again everywhere below is
that dW/dZ must be divisible by (z2 1), unless the compatibility
relations show that U(Z) would admit the points Z = 1 as singular
points which is inadmissible. Thus we introduce the function
F(Z) Z2 dW (III.2)
Z2 1 dZ
iand we shall attempt to determine F(Z) for the symmetrical as well as
for the lifting problem.
F(Z) is a holomorphic function inside of the domain (D), bounded
by the cut and the circle (CO); the only singular points this function
can present on the boundary of (D), are A and A'; on the other hand,
'iF(Z) must be divisible by Z2, unless U, V, W have singularities
at the origin. On the two edges of the cut F(Z) must have a real zero
part. On the circle (Co)
Z 1 1
Z2 1 Z 1 2i sin 0
Z
Z dW = e1 dW dW
dZ dZ dO
Consequently, F(Z) has a real zero part on (Co) as well. The fact
that F(Z) cannot be identically zero, and that its real part is zero
on the boundary of (D), admits A and A' as singular points. We
shall study the nature of these singularities.
3.1.1.2 Singularities of F(Z).- Physically, it is clear that A
Sand A' cannot be essential singular points. Let us therefore suppose
.that, in the neighborhood of Z = a, one has
26One assumes, as a start, that the problem permits the use of the
plane Ox1x3 as the plane of symmetry.
NACA TM 1354
F(Z) ~ K%(Z a)mo
m0 being arbitrary, KM / 0; let us put
Z a = rei
with Pq being equal to +- on the upper edge of the cut, to
the lower edge; for sufficiently small values of r
-it on
orO r" O"
and
KmO e-imo
W)e
must be purely imaginary quantities; thus the same will hold true for
KO cos molt
and for
iKm sin mon;
K 02 = Km02cos2m~ (i0 sin ms)2
is therefore real. On the other hand
2 sin 2mov
2 i2mus = (b cos n)( w ei sin n0g)
must be real which entails
sin 2m0A = 0
Thus there are two possibilities; let us denote by
integral; either
k an arbitrary
KmO is purely imaginary
or else
KmO is real.
mo = k + -,
mo = k,
SNACA TM 1354 83
Let us now consider
F1(Z) = F(Z) K(Z a)m0
In the neighborhood of Z = a
Fl(Z) ~ Kml(Z a)ml
and the same argument shows that 2mI must be an integral. Finally,
one may state the-following theorem:
Theorem: Inside of (Co) the function F(Z) may assume the form
F(Z) = O(Z) + 1 t(Z) (III.3)
a2 Z2
'with Q(Z) and 4(Z) admitting no singularities other than the poles
at A and A'.
The analysis we shall make will be simplified owing to certain
symmetry conditions which F(Z) satisfies. Let us put
W = w + iw'
Obviously, X in w(X,Y) is even (when Y is constant).
Consequently, F(Z) has a real part zero on OY. Applying
Schwartz' principle one may write
F(Z) = -F(-Z) (1I.4)
This equation shows that knowledge of the development of F(Z)
around Z = a immediately entails knowledge of F(Z) around Z = -a.
NACA TM 1354
3.1.1.3 Study of the case where F(Z) is uniform [c(Z) = -O.-
Let us consider the function
iz2P
Ap(Z) = iZ2
(a2 z2)(1 a2z2
with p an integral and >1.
This function satisfies all conditions imposed on F(Z).
Indeed, it satisfies equation (III.4); inside of (Co) it does
not admit singularities other than a and -a which are poles of the
order pl. Its real part is zero on the cut as well as on (CO), as
one can see when writing
Ap(Z)
2 (Z2 + )
a ( +
\ Z2~i
- (1 + a
Finally, the origin should be double zero (at least).
Let us assume F(Z) to be the general solution of the problem
stated; we shall then demonstrate the following theorem:
Theorem: If F(Z) is uniform, one has
n n
F(Z) = XpAp(Z) = i
11 ^a2
(III.6)
- Z2)1 a2Z21
with n being an integral, and the kp being real coefficients.
In case F(Z) is assumed to be a solution of the problem having a
pole of the order n, one can determine a number kn so that
Fl(Z) = F(Z) nAn(Z)
will be a solution admitting the pole Z = a only of an order not
higher than (n 1) at most. But in consequence of equation (III.4),
(III.5)
NACA TM 1354
F1(Z) will allow of Z = -a as pole of, at most, the order (n 1).
Proceeding by recurrence, one finally defines a function
n
Fn(Z) = F(Z) XpAp(Z)
1
which must satisfy all conditions of the problem and be holomorphic
inside of (CO). The boundary conditions on the circle and on the cut
entail Fn(Z) to be a constant which must be zero because Fn(Z) must
become zero at the origin.
3.1.1.4 Case where O(Z) = 0.- We shall study the case where
O(Z) = 0 in a perfectly analogous manner.
Let us put
f(Z) = F(a2 z)(l a2Z2) F(Z)
Z
f(Z) is a uniform function inside of (Co) which admits as poles only
the points (Z = -a, Z = a). Actually, the origin is not a pole since,
according to hypothesis, F(Z) is divisible by Z2. The function f(Z)
possesses the following properties: It is imaginary on the cut, real
on (Co), and real on OY (which entails properties of symmetry if one
changes Z to -Z). Moreover, f(Z) admits the origin as zero of, at
least, the order 1. All these properties appertain equally'to the
functions
\$r =(z 1 iZP-1 2 1)
Bp(Z) = Ap 1) = Z-(Z2 ) p
Z Z) a2 2)(1 a2Z2
p is an integral >1.
Thus one deduces, as before, the theorem:
Theorem: In the case where O(Z)
= 0, one may write
NACA TM 1354
F(Z) = i n Z2pP (III.7)
z21z 2
1 a2 Z2)(1 az2] 2
with n being an integral, the Ap being real.
3.1.1.5 The principle of "minimum singularities".- The for-
mulas (III.6) and (III.7) depend on an arbitrary number of coefficients.
The only datum we know is the wo, the value w assumes on the upper
edge of the cut. Thus we have to introduce a principle which will
guarantee the uniqueness of the solution of the problems we have set
ourselves. This principle which we shall call principle of the "minimum
singularities" may be formulated in the following manner (it is con-
stantly being employed in mathematical physics):
When the conditions of a problem require the introduction of func-
tions presenting singularities, one will, in a case of indeterminite-
ness, be satisfied with introducing the singularities of the lowest
possible order permitting a complete solution of the posed problem.
In the case which is of interest to us, this amounts to assuming
n = 1 in the formulas (III.6) and (III.7). For the problem of interest
to us, this principle has immediate significance; it amounts to stating
that F(Z) and hence dW/dZ must be of an order lower than 2 in
1/Z a, or W(Z) must be of an order lower than 1 with respect to that
same infinity; the considerations set forth in section 2.2.7 show that
these conditions entail the total energy to remain finite.
3.1.1.6 Solution of the elementary symmetrical problem.- Let us
turn again to formula (III.6); one deduces from it, according to equa-
tion (III.2), that in the case where F(Z) is uniform
dW Z2 1
ik
dZ 41 (a2 Z2)(i a2Z2)
and hence
W(Z) = 1 log (a Z)(1 aZ)
2a(l + a2) (a + Z)(1 + aZ)
NACA TM 1354
The determination of the logarithm is just that the real part of W(Z)
is zero on (Co). Besides
2a(l + a2)wo
On the upper edge of the cut
w = w0
and on the lower edge w assumes the opposite value. This shows us that
the case investigated is that of the symmetrical problem. The value W(Z)
for this problem is therefore
W(z) IW- lo(a Z)(1 aZ)
i (a + Z)(l + aZ)
(III.8)
The calculation of the functions U(Z) and V(Z) offers no diffi-
culty whatsoever. It suffices to apply the relationships of compati-
bility (1.25) and to integrate; the only precaution to be taken consists
in choosing the constant of integration in such a manner that the real
parts of U and V on (CO) become zero; one then finds
v(z) -~oW (1 + a2)
u(z) -2
p(1 a2
(a + Z)(1 aZ)
g(Z a)(l + aZ)
Z -a2
S log a! -
) 1 a2Z2]
This last formula is the most interesting one since it permits calcula-
tion of the pressure coefficient (see formula (1.8)). One finds
4C W a [loga2-X2]
p p 1 a2 1 a2x2
(III.9)
(III.10)
(III.11)
88 NACA TM 1354
In order to interpret this formula, one must connect the quanti-
ties a, X, to geometrical quantities, related to the given cone. Fire:
of all
w0 =a
a being the constant
hand
inclination of the cone on
2X = r -= tan u
1 + X2 x
Ox. On the other
whence
= cos w 1 M2sin2
0 sin w
(see fig. 32) and
cos CU \ M2sin2w0
p sin a0
In figure 33 one will find the curves giving the values of
functions of o, for various Mach numbers and various values of
(III.12)
Cp as
CO'
3.1.1.7 Solution of the elementary lifting problem.- If one
starts from the formula (III.7), one obtains
dW =
dZ
(2 1)2
Fa2 Z2)(1 a2z2)] 2
The integration which yields W(Z) introduces elliptic functions (see
section 3.1.1.8); on the other hand, it will (now) be possible to cal-
culate U(Z). We note beforehand that, according to the preceding for-
mula, W(Z) assumes the same value on the two edges of the cut and
that, consequently, this solution corresponds to the lifting problem.
N:ACA TM 1354
The relationships of compatibility show that
dU 2X1
dZ B
z(z2 )
(a2 2) (1 a2z2)] 2
U(z) = 2X1
We s + 1)2 ka
We still have to calculate 1 a
Z2 + 1
Z2)(1 a2Z2 2
s a function of w,
(III.13)
For this
purpose, one may write
-wO = d dZ = iil
0 dZ
We put in this integral Z = iu
T (z2 i)-
Z[ 2 1)2d
[a2 2)(1 a2Z2) 2
Wo = 1 f (+ = Ull(a)
S a2 + u2)( + a2u2) 2
The calculation of I(a) can be made with the aid of the function E
(see ref. 24). We shall put
u+ 2
u t
After a few calculations one obtains
I(a) =4 dt
+ (a t2 2 2 1)2t]2
0 1 .
and hence
NACA TM 1354
Finally, the change in variable
sin = t(a2 + 1)
4a2 + (a2 )2t2
shows that if one puts
1 a2
1 + a2
a2(a2 + 1) O
dT = 1
a2(a2 + 1)
Hence the new formula for U(Z)
u(z) 2 a20w
a (a2 + )E1 + a2
(a2
Z2 + 1
1
_Z2)(1 a272) 2
We still have to
One has (fig. 32)
connect a
and Z to the geometrical quantities.
2a
1 + a2
- 3 tan i'0
2X
1 + X2
One puts
t tan u
tan nLQ
and obtains
w0 tan l 0 1
EL 02tan2 o] t2
E a
1 + a
fi-^
li<*^
(III.14)
= 0 tan J | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9306462407112122, "perplexity": 4204.213215673497}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-34/segments/1502886103891.56/warc/CC-MAIN-20170817170613-20170817190613-00711.warc.gz"} |
https://edboost.org/practice/solving-quadratic-equations-completing-square | # Solving Quadratic Equations: Completing the Square
Common Core Grade Level:
Packet includes:
30 practice problems and an answer key.
This packet helps students understand how to solve equations by "completing the square."
Each page starts with easier problems that get more difficult as students work through the packet. After doing all 30 problems, students should be more comfortable doing these problems and have a clear understanding of how to solve them.
Sample Problem(s):
Solve for the unknown variable. Complete the square where needed.
Simple:
$x²+2x=1$
$2x²+4x=10$
Notes:
Practice problems require knowledge of addition, subtraction, multiplication, and division of integers.
Students must know how to find square roots.
Video lesson(s) showing you how to do this type of problem: | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6330223083496094, "perplexity": 1158.0703556507103}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-39/segments/1631780058589.72/warc/CC-MAIN-20210928002254-20210928032254-00633.warc.gz"} |
http://mathoverflow.net/questions/114918/borel-group-on-r/114932 | Borel Group on R [closed]
Last week in class we used the fact that if we have a group within R which is also a Borel Set, then it is either R or meagre. Why is it so? Can you direct me to a proof?
-
closed as off topic by Bill Johnson, Andres Caicedo, Qiaochu Yuan, Benoît Kloeckner, Ryan BudneyNov 30 '12 at 19:51
Questions on MathOverflow are expected to relate to research level mathematics within the scope defined by the community. Consider editing the question or leaving comments for improvement if you believe the question can be reworded to fit within the scope. Read more about reopening questions here. If this question can be reworded to fit the rules in the help center, please edit the question.
This is a version of Steinhaus's theorem: en.wikipedia.org/wiki/Steinhaus_theorem A proof of a natural generalization, Pettis's theorem, is in Kechris's book Classical descriptive set theory (somewhere in chapter 9, I believe): books.google.com/books?id=pE1VMQEACAAJ – Theo Buehler Nov 29 '12 at 21:13
1 Answer
These notes written by Julien Melleray help us to solve the problem. I just state the results which will help in our case.
Lemma 3.3 (Pettis) Let $G$ a Polish group. For $A\subset G$, define $U(A)$ as the biggest open set $V$ such that $A$ is comeagre $V$. For any subsets $A$ and $B$ of $G$, we have $$U(A)\cdot U(B)\subset A\cdot B.$$
As a consequence:
Theorem 3.4 Let $G$ a Polish group, and $A$ a Baire measurable non-meagre subset of $G$. Then $e$, the neutral element, belongs to the interior of $A\cdot A^{-1}$.
Back to the problem. Of course, $\Bbb R$ with the addition is a Polish group. Let $H$ a subgroup of $\Bbb R$ which is non-meagre and Borel measurable. It's Baire measurable. By the last theorem, $e$ belongs to the interior of $H\cdot H^{-1}=H$ as $H$ is a sub-group.
It's well-know that the subgroups of $\Bbb R$ are either of the form $a\Bbb Z$ (hence meagre) or dense. So we have a subgroup $H$ which is dense and has non-empty interior, say $(-r,r)$. Let $x\in \Bbb R$, and $x'\in H$ such that $|x-x'|\lt r$. Then $x-x'\in H$ and $x\in H$.
-
+1 for linking to Julien Melleray's notes, they look very nice at a first glance. I saw that you started with your PhD thesis: Good luck with it! Best wishes (t.b. from math.SE). – Theo Buehler Nov 29 '12 at 21:31
Please keep in mind that the notes have not been carefully re-read and probably contain mistakes (and I'll be grateful, should you find any, if you let me know!)... Also, in the case of $\mathbb R$, probably the easiest way to answer the question is to use the Lebesgue measure, via the following statement (due to Steinhaus, I believe): if $A \subset \mathbb R$ is measurable of positive measure, then $A−A$ contains an interval centered around $0$ (this is a classical consequence of the regularity of the Lebesgue measure) – Julien Melleray Nov 29 '12 at 21:41
Thanks! I hope I will have luck with it, which will be the least we could expect of a probabilist! – Davide Giraudo Nov 29 '12 at 21:43
@Julien I thought about that, and it proves that a subgroup is either $\Bbb R$ or has $0$ measure. Is there a simple way to see it's meagre? – Davide Giraudo Nov 29 '12 at 21:45
A word of warning: Baire measurable is not the same as measurable with respect to the Baire $\sigma$-algebra (the $\sigma$-algebra generated by the compact $G_\delta$'s). It means the $\sigma$-algebra generated by the open sets and the meagre sets. There are meagre sets that aren't Borel: every set of reals can be written as the disjoint union of a meagre set $A$ and a Lebesgue null set $B$. If you partition a Vitali set this way: $V = A \cup B$ then $A$ can't even be Lebesgue measurable but is Baire measurable. – Theo Buehler Nov 29 '12 at 21:46 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9029480814933777, "perplexity": 238.96939776058443}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-22/segments/1432207928864.16/warc/CC-MAIN-20150521113208-00085-ip-10-180-206-219.ec2.internal.warc.gz"} |
https://www.physicsforums.com/threads/probability-theory-2.213531/ | # Probability theory 2
1. Feb 6, 2008
### Milky
1. The problem statement, all variables and given/known data
The homework question I have is:
Let X be uniform over (0,1). Find E[X|X<1/2].
3. The attempt at a solution
First I found the density function: f(x|x<1/2] = f(x∩x<1/2) / f(x<1/2) = f(x<1/2) / f(x<1/2) = 1.
So, E[X|X<1/2] = ∫ xdx
My question is... are the limits of integration suppose to be from 0 to 1, or 0 to 1/2? Is everything else correct?
2. Feb 6, 2008
### EnumaElish
The limits of integration are {0, 1/2} because f(x|X<1/2) is defined (or is positive) for x<1/2 only.
This information should also alert you to the fact that $$\int_0^{1/2}f(x|X<1/2)dx = 1$$ has to be the case. Does f(x|x<1/2) = 1 satisfy this condition?
3. Feb 6, 2008
### Milky
Okay, new strategy. In my textbook in a similar problem, they did:
f(x|x<1/2) = f(x) / P{x<1/2}
When I do that, I get
f(x) / P{x<1/2} = 1 / (1/2) = 2.
E[x|x<1/2] = $$\int_0^{1/2}2xdx$$
= 1/4
Last edited: Feb 6, 2008
Similar Discussions: Probability theory 2 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9409748315811157, "perplexity": 3189.2350136631}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-47/segments/1510934806438.11/warc/CC-MAIN-20171121223707-20171122003707-00724.warc.gz"} |
https://www.clutchprep.com/chemistry/practice-problems/96424/what-is-the-evidence-that-all-neutral-atoms-and-molecules-exert-attractive-force | # Problem: What is the evidence that all neutral atoms and molecules exert attractive forces on each other?
⚠️Our tutors found the solution shown to be helpful for the problem you're searching for. We don't have the exact solution yet.
###### Problem Details
What is the evidence that all neutral atoms and molecules exert attractive forces on each other? | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9851852059364319, "perplexity": 474.7514071388468}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-29/segments/1593655924908.55/warc/CC-MAIN-20200711064158-20200711094158-00020.warc.gz"} |
https://qiskit.org/documentation/locale/de_DE/stubs/qiskit.quantum_info.partial_trace.html | # qiskit.quantum_info.partial_trace¶
partial_trace(state, qargs)[Quellcode]
Return reduced density matrix by tracing out part of quantum state.
If all subsystems are traced over this returns the trace() of the input state.
Parameter
Rückgabe
The reduced density matrix.
Rückgabetyp
DensityMatrix
Verursacht
QiskitError – if input state is invalid. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6869891285896301, "perplexity": 5184.973364258937}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 20, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-17/segments/1618038089289.45/warc/CC-MAIN-20210416191341-20210416221341-00615.warc.gz"} |
https://www.physicsforums.com/threads/why-is-this-integral-positive-or-negative.107898/ | # Why is this integral positive or negative
1. Jan 24, 2006
### Natasha1
I have been asked to explain without evaluating the integrals why
1) the integral of x cos x from 0 to pi/2 is positive and the integral of x cos x from pi/2 to pi is negative. And also would I expect x cos x from 0 to pi to be positive, zero or negative??? And why ???
2) to find the indefinite integral of x cos x dx and hence the exact values of values of x cos x from 0 to pi/2, cos x from pi/2 to pi and x cos x from 0 to pi?
Any help would be must appreciated. I know I haven't done anything so far so no need to have a go at me for it but I just wanted some help with it and even better the solutions obviously as this blimming thing is for in a few days time. Many thanks in advance
Nat
2. Jan 24, 2006
### siddharth
1) What are your thoughts on this? Have you drawn the graph?
2) Have you learnt about integration by parts?
3. Jan 24, 2006
### Jameson
$$\int x\cos(x)dx$$
By parts, u=x dv=cos(x)
du = 1 v = sin(x)
$$\int udv= uv - \int vdu$$
You can take it from there.
4. Jan 25, 2006
### VietDao29
#1, What can you say about the integral of $$\int \limits_{\alpha} ^ {\beta} f(x) \ dx$$ (i.e greater or less than or equal to 0), if:
(i) $f(x) > 0 , \ \forall x \in ( \alpha, \ \beta )$
(ii) $f(x) < 0 , \ \forall x \in ( \alpha, \ \beta )$?
You can draw a graph to see this. Remember that definite integral of some function from a to b will give you the area under the graph of that function from x = a to x = b.
#2, as others have pointed out, this should be done by Integration by parts.
You can either read the article there, or look at your text book. There should be something about Integration by parts.
Can you go from here? If you still have problems, just shout out.
Last edited: Jan 25, 2006 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9522086381912231, "perplexity": 429.15700231782387}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-04/segments/1547583658681.7/warc/CC-MAIN-20190117020806-20190117042806-00333.warc.gz"} |
http://www.apmonitor.com/wiki/index.php/Main/DifferentialVariables?action=diff&source=n&minor=y | Main
## Main.DifferentialVariables History
June 16, 2015, at 06:44 PM by 45.56.3.184 -
Deleted lines 0-1:
## Differential Variables
Changed line 13 from:
(:table border=1 width=50% align=left bgcolor=#EEEEEE cellspacing=0:)
to:
(:table border=1 width=100% align=left bgcolor=#EEEEEE cellspacing=0:)
April 23, 2009, at 04:54 PM by 158.35.225.231 -
Changed lines 29-30 from:
! x is the first order lag of parameter u with time constant tau
to:
! x is the first order lag of parameter u
! with time constant tau
October 09, 2008, at 01:22 PM by 158.35.225.231 -
Changed line 3 from:
Differential states are variables that have the differential operator ($) applied in at least one equation. These differential states are declared in the variables section without the differential operator. For dynamic problems, the differential variables are converted to algebraic variables through orthogonal collocation on finite elements. This form allows dynamic problems to be solved by nonlinear programming (NLP) solvers. to: Differential states are variables that have the differential operator ($) applied in at least one equation. These differential states are declared in the variables section without the differential operator. For dynamic problems, the differential variables are converted to algebraic variables through orthogonal collocation on finite elements. This discretized form allows dynamic problems to be solved by nonlinear programming (NLP) solvers.
October 09, 2008, at 12:58 PM by 158.35.225.231 -
Changed line 3 from:
Differential states are variables that have the differential operator ($) applied in at least one equation. These differential states are declared in the variables section as any other variable. to: Differential states are variables that have the differential operator ($) applied in at least one equation. These differential states are declared in the variables section without the differential operator. For dynamic problems, the differential variables are converted to algebraic variables through orthogonal collocation on finite elements. This form allows dynamic problems to be solved by nonlinear programming (NLP) solvers.
September 25, 2008, at 06:42 PM by 158.35.225.230 -
Changed lines 1-6 from:
### Consistent Initial Conditions
Forward stepping algorithms such as DASSL, DASPK, or CVODE generally require ordinary differential equations (ODEs) or index-1 differential algebraic equations (DAEs) and consistent initial conditions. This is not a restriction with simultaneous methods as used by APMonitor. Also, ODEs or DAEs of any index can be solved.
to:
## Differential Variables
Differential states are variables that have the differential operator () applied in at least one equation. These differential states are declared in the variables section as any other variable. ### DAE Index Restrictions Differential and algebraic equation (DAE) index is the number of times equations must be differentiated to restore them to an ODE form. Higher (>=2) index DAE problems are overcome with techniques used in this software. ODEs or DAEs of any index can be solved. ### Consistent Initial Conditions for Dynamic Problems Sequential ODE and DAE solution approaches require consistent initial conditions. This is not a restriction with APMonitor because of the simultaneous approach. The initial conditions do not have to be consistent to achieve a feabile solution. The time-shifting approach guarantees that the initial conditions are consistent after one cycle. ### Example (:table border=1 width=50% align=left bgcolor=#EEEEEE cellspacing=0:) (:cellnr:) ! Example model with a differential equation Model example Parameters u = 1 ! input tau = 5 ! time constant End Parameters Variables x = 1 ! initial condition End Variables Equations ! x is the first order lag of parameter u with time constant tau tau *x = -x + u
End Equations
End Model
(:tableend:)
September 25, 2008, at 06:32 PM by 158.35.225.230 - | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8409579396247864, "perplexity": 2419.823173287881}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-43/segments/1539583511122.49/warc/CC-MAIN-20181017090419-20181017111919-00529.warc.gz"} |
http://www.ams.org/joursearch/servlet/DoSearch?f1=msc&v1=14G05&jrnl=one&onejrnl=bull | # American Mathematical Society
Publications Meetings The Profession Membership Programs Math Samplings Policy and Advocacy In the News About the AMS
You are here: Home > Publications
AMS eContent Search Results
Matches for: msc=(14G05) AND publication=(bull) Sort order: Date Format: Standard display
Results: 1 to 8 of 8 found Go to page: 1
[1] Karl Rubin and Alice Silverberg. Ranks of elliptic curves. Bull. Amer. Math. Soc. 39 (2002) 455-474. MR 1920278. Abstract, references, and article information View Article: PDF [2] János Kollár. Which are the simplest algebraic varieties?. Bull. Amer. Math. Soc. 38 (2001) 409-433. MR 1848255. Abstract, references, and article information View Article: PDF [3] Anand Pillay. Model theory and diophantine geometry. Bull. Amer. Math. Soc. 34 (1997) 405-422. MR 1458425. Abstract, references, and article information View Article: PDF [4] Helmut Völklein. ${\text{PSL}}_2 \left( q \right)$ and extensions of ${\mathbf{Q}}\left( x \right)$. Bull. Amer. Math. Soc. 24 (1991) 145-153. MR 1060151. Abstract, references, and article information View Article: PDF [5] Stephen Kudla. On the ${\mathbf{R}}$-forms of certain algebraic varieties. Bull. Amer. Math. Soc. 81 (1975) 471-473. MR 0379505. Abstract, references, and article information View Article: PDF [6] A. P. Ogg. Diophantine equations and modular forms. Bull. Amer. Math. Soc. 81 (1975) 14-27. MR 0354675. Abstract, references, and article information View Article: PDF [7] Don Goelman. Rational critical points of the reduced norm of an algebra. Bull. Amer. Math. Soc. 80 (1974) 138-141. MR 0337877. Abstract, references, and article information View Article: PDF [8] L. G. Roberts. An algebraic proof of an analytic result of Shuck's. Bull. Amer. Math. Soc. 79 (1973) 754-757. MR 0327764. Abstract, references, and article information View Article: PDF
Results: 1 to 8 of 8 found Go to page: 1 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9580324292182922, "perplexity": 3010.000951999532}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-06/segments/1422115858580.32/warc/CC-MAIN-20150124161058-00231-ip-10-180-212-252.ec2.internal.warc.gz"} |
http://ciw.readthedocs.io/en/latest/Tutorial-II/tutorial_vi.html | # Tutorial VI: Restricted Networks¶
Imagine a manufacturing plant that produces stools:
• Every 4 seconds a seat arrives on a conveyor-belt.
• The belt contains three workstations.
• At the each workstation a leg is connected.
• Connecting a leg takes a random amount of time between 3 seconds and 5 seconds.
• Between workstations (and before the first workstation) the conveyor-belt is only long enough to hold 3 stools.
• If the belt before the first workstation is full then new stools fall to the floor and break.
• If a stool finishes ‘service’ at a workstation, but there is no space on the conveyor-belt, that stool must remain at the workstation until room becomes available on the conveyor-belt. While this blockage happens, that workstation cannot begin assembling any more stools. (Full details on blocking available here.)
Each broken stool costs the factory 10p in wasted wood. We wish to know how many stools will fall to the floor and break per hour of operation, and thus the average cost per hour. First let’s define the Network. A restricted network such as this is represented by nearly the same Network object as an unrestricted network, but we now include the keyword Queue_capacities:
>>> import ciw
>>> N = ciw.create_network(
... Arrival_distributions=[['Deterministic', 4.0],
... 'NoArrivals',
... 'NoArrivals'],
... Service_distributions=[['Uniform', 3, 5],
... ['Uniform', 3, 5],
... ['Uniform', 3, 5]],
... Transition_matrices=[[0.0, 1.0, 0.0],
... [0.0, 0.0, 1.0],
... [0.0, 0.0, 0.0]],
... Number_of_servers=[1, 1, 1],
... Queue_capacities=[3, 3, 3]
... )
The time taken to attach a leg to the stool (service time) is sampled using the uniform distribution. This samples values equally likely between an upper and lower limit. Note the time units here are in seconds.
If we simulate this, we have access to information about the blockages, for example the amount of time a stool was spent blocked at each node. To illustrate, let’s simulate for 20 minutes:
>>> ciw.seed(2)
>>> Q = ciw.Simulation(N)
>>> Q.simulate_until_max_time(1200)
>>> recs = Q.get_all_records()
>>> blockages = [r.time_blocked for r in recs]
>>> max(blockages)
1.503404...
Here we see that in 20 minutes the maximum time a stool was blocked at a workstation for was 1.5 seconds.
We can get information about the stools that fell off the conveyor-belt using the Simulation’s rejection_dict attribute. This is a dictionary, that maps node numbers to dictionaries. These dictionaries map customer class numbers to a list of dates at which customers where rejected:
>>> Q.rejection_dict
{1: {0: [740.0, 960.0, 1140.0]}, 2: {0: []}, 3: {0: []}}
In this run 3 stools were rejected (fell to the floor as there was no room on the conveyor-belt) at Node 1, at times 740, 960, and 1140. To get the number of stools rejected, take the length of this list:
>>> len(Q.rejection_dict[1][0])
3
Now we’ll run 8 trials, and get the average number of rejections in an hour. We will take a warm-up time of 10 minutes. A cool-down will be unnecessary as we are recording rejections, which happen at the time of arrival:
>>> broken_stools = []
>>> for trial in range(8):
... ciw.seed(trial)
... Q = ciw.Simulation(N)
... Q.simulate_until_max_time(4200)
... num_broken = len([r for r in Q.rejection_dict[1][0] if r > 600])
... broken_stools.append(num_broken)
>>> broken_stools
[7, 4, 7, 8, 5, 8, 9, 6]
>>> sum(broken_stools)/len(broken_stools)
6.75
On average the system gets 6.75 broken stools per hour; costing and average of 67.5p per hour of operation.
A new stool assembly system, costing £2500, can reduce the variance in the leg assembly time, such that it takes between 3.5 and 4.5 seconds to attach a leg. How many hours of operation will the manufacturing plant need to run for so that the new system has saved the plant as much money as it costed?
First, under the new system how many broken stools per hour do we expect?:
>>> N = ciw.create_network(
... Arrival_distributions=[['Deterministic', 4.0],
... 'NoArrivals',
... 'NoArrivals'],
... Service_distributions=[['Uniform', 3.5, 4.5],
... ['Uniform', 3.5, 4.5],
... ['Uniform', 3.5, 4.5]],
... Transition_matrices=[[0.0, 1.0, 0.0],
... [0.0, 0.0, 1.0],
... [0.0, 0.0, 0.0]],
... Number_of_servers=[1, 1, 1],
... Queue_capacities=[3, 3, 3]
... )
>>> broken_stools = []
>>> for trial in range(8):
... ciw.seed(trial)
... Q = ciw.Simulation(N)
... Q.simulate_until_max_time(4200)
... num_broken = len([r for r in Q.rejection_dict[1][0] if r > 600])
... broken_stools.append(num_broken)
>>> sum(broken_stools) / len(broken_stools)
0.875
Thus the new system saves an average of 5.875 stools per hour, around 58.75p per hour. Therefore it would take $$2500/0.5875 \approx 4255.32$$ hours of operation for the system to begin paying off. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5561872124671936, "perplexity": 5180.263571711011}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-13/segments/1521257647576.75/warc/CC-MAIN-20180321043531-20180321063531-00138.warc.gz"} |
http://is.tue.mpg.de/publications?year%5B%5D=&year%5B%5D=2015 | 244 results
2015
Exploiting Object Similarity in 3D Reconstruction
Zhou, C., Güney, F., Wang, Y., Geiger, A.
In International Conference on Computer Vision (ICCV), December 2015 (inproceedings)
Abstract
Despite recent progress, reconstructing outdoor scenes in 3D from movable platforms remains a highly difficult endeavor. Challenges include low frame rates, occlusions, large distortions and difficult lighting conditions. In this paper, we leverage the fact that the larger the reconstructed area, the more likely objects of similar type and shape will occur in the scene. This is particularly true for outdoor scenes where buildings and vehicles often suffer from missing texture or reflections, but share similarity in 3D shape. We take advantage of this shape similarity by locating objects using detectors and jointly reconstructing them while learning a volumetric model of their shape. This allows us to reduce noise while completing missing surfaces as objects of similar shape benefit from all observations for the respective category. We evaluate our approach with respect to LIDAR ground truth on a novel challenging suburban dataset and show its advantages over the state-of-the-art.
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2015
FollowMe: Efficient Online Min-Cost Flow Tracking with Bounded Memory and Computation
Lenz, P., Geiger, A., Urtasun, R.
In International Conference on Computer Vision (ICCV), International Conference on Computer Vision (ICCV), December 2015 (inproceedings)
Abstract
One of the most popular approaches to multi-target tracking is tracking-by-detection. Current min-cost flow algorithms which solve the data association problem optimally have three main drawbacks: they are computationally expensive, they assume that the whole video is given as a batch, and they scale badly in memory and computation with the length of the video sequence. In this paper, we address each of these issues, resulting in a computationally and memory-bounded solution. First, we introduce a dynamic version of the successive shortest-path algorithm which solves the data association problem optimally while reusing computation, resulting in faster inference than standard solvers. Second, we address the optimal solution to the data association problem when dealing with an incoming stream of data (i.e., online setting). Finally, we present our main contribution which is an approximate online solution with bounded memory and computation which is capable of handling videos of arbitrary length while performing tracking in real time. We demonstrate the effectiveness of our algorithms on the KITTI and PETS2009 benchmarks and show state-of-the-art performance, while being significantly faster than existing solvers.
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Scalable Robust Principal Component Analysis using Grassmann Averages
Hauberg, S., Feragen, A., Enficiaud, R., Black, M.
IEEE Trans. Pattern Analysis and Machine Intelligence (PAMI), December 2015 (article)
Abstract
In large datasets, manual data verification is impossible, and we must expect the number of outliers to increase with data size. While principal component analysis (PCA) can reduce data size, and scalable solutions exist, it is well-known that outliers can arbitrarily corrupt the results. Unfortunately, state-of-the-art approaches for robust PCA are not scalable. We note that in a zero-mean dataset, each observation spans a one-dimensional subspace, giving a point on the Grassmann manifold. We show that the average subspace corresponds to the leading principal component for Gaussian data. We provide a simple algorithm for computing this Grassmann Average (GA), and show that the subspace estimate is less sensitive to outliers than PCA for general distributions. Because averages can be efficiently computed, we immediately gain scalability. We exploit robust averaging to formulate the Robust Grassmann Average (RGA) as a form of robust PCA. The resulting Trimmed Grassmann Average (TGA) is appropriate for computer vision because it is robust to pixel outliers. The algorithm has linear computational complexity and minimal memory requirements. We demonstrate TGA for background modeling, video restoration, and shadow removal. We show scalability by performing robust PCA on the entire Star Wars IV movie; a task beyond any current method. Source code is available online.
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Intrinsic Depth: Improving Depth Transfer with Intrinsic Images
In IEEE International Conference on Computer Vision (ICCV), pages: 3514-3522, International Conference on Computer Vision (ICCV), December 2015 (inproceedings)
Abstract
We formulate the estimation of dense depth maps from video sequences as a problem of intrinsic image estimation. Our approach synergistically integrates the estimation of multiple intrinsic images including depth, albedo, shading, optical flow, and surface contours. We build upon an example-based framework for depth estimation that uses label transfer from a database of RGB and depth pairs. We combine this with a method that extracts consistent albedo and shading from video. In contrast to raw RGB values, albedo and shading provide a richer, more physical, foundation for depth transfer. Additionally we train a new contour detector to predict surface boundaries from albedo, shading, and pixel values and use this to improve the estimation of depth boundaries. We also integrate sparse structure from motion with our method to improve the metric accuracy of the estimated depth maps. We evaluate our Intrinsic Depth method quantitatively by estimating depth from videos in the NYU RGB-D and SUN3D datasets. We find that combining the estimation of multiple intrinsic images improves depth estimation relative to the baseline method.
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Enzymatically active biomimetic micropropellers for the penetration of mucin gels
Walker, D., Käsdorf, B. T., Hyeon-Ho, J., Lieleg, O., Fischer, P.
Science Advances, 1(11), American Association for the Advancement of Science, December 2015 (article)
Abstract
In the body, mucus provides an important defense mechanism by limiting the penetration of pathogens. It is therefore also a major obstacle for the efficient delivery of particle-based drug carriers. The acidic stomach lining in particular is difficult to overcome because mucin glycoproteins form viscoelastic gels under acidic conditions. The bacterium Helicobacter pylori has developed a strategy to overcome the mucus barrier by producing the enzyme urease, which locally raises the pH and consequently liquefies the mucus. This allows the bacteria to swim through mucus and to reach the epithelial surface. We present an artificial system of reactive magnetic micropropellers that mimic this strategy to move through gastric mucin gels by making use of surface-immobilized urease. The results demonstrate the validity of this biomimetic approach to penetrate biological gels, and show that externally propelled microstructures can actively and reversibly manipulate the physical state of their surroundings, suggesting that such particles could potentially penetrate native mucus.
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Detailed Full-Body Reconstructions of Moving People from Monocular RGB-D Sequences
In International Conference on Computer Vision (ICCV), pages: 2300-2308, December 2015 (inproceedings)
Abstract
We accurately estimate the 3D geometry and appearance of the human body from a monocular RGB-D sequence of a user moving freely in front of the sensor. Range data in each frame is first brought into alignment with a multi-resolution 3D body model in a coarse-to-fine process. The method then uses geometry and image texture over time to obtain accurate shape, pose, and appearance information despite unconstrained motion, partial views, varying resolution, occlusion, and soft tissue deformation. Our novel body model has variable shape detail, allowing it to capture faces with a high-resolution deformable head model and body shape with lower-resolution. Finally we combine range data from an entire sequence to estimate a high-resolution displacement map that captures fine shape details. We compare our recovered models with high-resolution scans from a professional system and with avatars created by a commercial product. We extract accurate 3D avatars from challenging motion sequences and even capture soft tissue dynamics.
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3D Object Reconstruction from Hand-Object Interactions
In International Conference on Computer Vision (ICCV), pages: 729-737, International Conference on Computer Vision (ICCV), December 2015 (inproceedings)
Abstract
Recent advances have enabled 3d object reconstruction approaches using a single off-the-shelf RGB-D camera. Although these approaches are successful for a wide range of object classes, they rely on stable and distinctive geometric or texture features. Many objects like mechanical parts, toys, household or decorative articles, however, are textureless and characterized by minimalistic shapes that are simple and symmetric. Existing in-hand scanning systems and 3d reconstruction techniques fail for such symmetric objects in the absence of highly distinctive features. In this work, we show that extracting 3d hand motion for in-hand scanning effectively facilitates the reconstruction of even featureless and highly symmetric objects and we present an approach that fuses the rich additional information of hands into a 3d reconstruction pipeline, significantly contributing to the state-of-the-art of in-hand scanning.
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Untethered Magnetic Micromanipulation
Diller, E., Sitti, M.
In Micro-and Nanomanipulation Tools, 13, 10, Wiley-VCH Verlag GmbH & Co. KGaA, November 2015 (inbook)
Abstract
This chapter discusses the methods and state of the art in microscale manipulation in remote environments using untethered microrobotic devices. It focuses on manipulation at the size scale of tens to hundreds of microns, where small size leads to a dominance of microscale physical effects and challenges in fabrication and actuation. To motivate the challenges of operating at this size scale, the chapter includes coverage of the physical forces relevant to microrobot motion and manipulation below the millimeter-size scale. It then introduces the actuation methods commonly used in untethered manipulation schemes, with particular focus on magnetic actuation due to its wide use in the field. The chapter divides these manipulation techniques into two types: contact manipulation, which relies on direct pushing or grasping of objects for motion, and noncontact manipulation, which relies indirectly on induced fluid flow from the microrobot motion to move objects without any direct contact.
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Learning Torque Control in Presence of Contacts using Tactile Sensing from Robot Skin
Calandra, R., Ivaldi, S., Deisenroth, M., Peters, J.
In 15th IEEE-RAS International Conference on Humanoid Robots, pages: 690-695, Humanoids, November 2015 (inproceedings)
am ei
Evaluation of Interactive Object Recognition with Tactile Sensing
Hoelscher, J., Peters, J., Hermans, T.
In 15th IEEE-RAS International Conference on Humanoid Robots, pages: 310-317, Humanoids, November 2015 (inproceedings)
am ei
Method and device for recovering a digital image from a sequence of observed digital images
European Patent, No. 11767924.1, November 2015 (patent)
ei
Distributed Event-based State Estimation
Max Planck Institute for Intelligent Systems, November 2015 (techreport)
Abstract
An event-based state estimation approach for reducing communication in a networked control system is proposed. Multiple distributed sensor-actuator-agents observe a dynamic process and sporadically exchange their measurements and inputs over a bus network. Based on these data, each agent estimates the full state of the dynamic system, which may exhibit arbitrary inter-agent couplings. Local event-based protocols ensure that data is transmitted only when necessary to meet a desired estimation accuracy. This event-based scheme is shown to mimic a centralized Luenberger observer design up to guaranteed bounds, and stability is proven in the sense of bounded estimation errors for bounded disturbances. The stability result extends to the distributed control system that results when the local state estimates are used for distributed feedback control. Simulation results highlight the benefit of the event-based approach over classical periodic ones in reducing communication requirements.
am ics
Optimizing Robot Striking Movement Primitives with Iterative Learning Control
Koc, O., Maeda, G., Neumann, G., Peters, J.
In 15th IEEE-RAS International Conference on Humanoid Robots, pages: 80-87, Humanoids, November 2015 (inproceedings)
am ei
easyGWAS: An Integrated Computational Framework for Advanced Genome-Wide Association Studies
Grimm, Dominik
Eberhard Karls Universität Tübingen, November 2015 (phdthesis)
ei
A Comparison of Contact Distribution Representations for Learning to Predict Object Interactions
Leischnig, S., Luettgen, S., Kroemer, O., Peters, J.
In 15th IEEE-RAS International Conference on Humanoid Robots, pages: 616-622, Humanoids, November 2015 (inproceedings)
am ei
Quantifying changes in climate variability and extremes: Pitfalls and their overcoming
Sippel, S., Zscheischler, J., Heimann, M., Otto, F. E. L., Peters, J., Mahecha, M. D.
Geophysical Research Letters, 42(22):9990-9998, November 2015 (article)
ei
First-Person Tele-Operation of a Humanoid Robot
Fritsche, L., Unverzagt, F., Peters, J., Calandra, R.
In 15th IEEE-RAS International Conference on Humanoid Robots, pages: 997-1002, Humanoids, November 2015 (inproceedings)
am ei
Probabilistic Segmentation Applied to an Assembly Task
Lioutikov, R., Neumann, G., Maeda, G., Peters, J.
In 15th IEEE-RAS International Conference on Humanoid Robots, pages: 533-540, Humanoids, November 2015 (inproceedings)
am ei
Diversity of sharp wave-ripple LFP signatures reveals differentiated brain-wide dynamical events
Ramirez-Villegas, J. F., Logothetis, N. K., Besserve, M.
Proceedings of the National Academy of Sciences U.S.A, 112(46):E6379-E6387, November 2015 (article)
ei
Reducing Student Anonymity and Increasing Engagement
University of Pennsylvania Almanac, 62(18):8, November 2015 (article)
hi
A 5-D localization method for a magnetically manipulated untethered robot using a 2-D array of Hall-effect sensors
Son, D., Yim, S., Sitti, M.
IEEE/ASME Transactions on Mechatronics, 21(2):708-716, IEEE, October 2015 (article)
Abstract
This paper introduces a new five-dimensional localization method for an untethered meso-scale magnetic robot, which is manipulated by a computer-controlled electromagnetic system. The developed magnetic localization setup is a two-dimensional array of mono-axial Hall-effect sensors, which measure the perpendicular magnetic fields at their given positions. We introduce two steps for localizing a magnetic robot more accurately. First, the dipole modeled magnetic field of the electromagnet is subtracted from the measured data in order to determine the robot's magnetic field. Secondly, the subtracted magnetic field is twice differentiated in the perpendicular direction of the array, so that the effect of the electromagnetic field in the localization process is minimized. Five variables regarding the position and orientation of the robot are determined by minimizing the error between the measured magnetic field and the modeled magnetic field in an optimization method. The resulting position error is 2.1±0.8 mm and angular error is 6.7±4.3° within the applicable range (5 cm) of magnetic field sensors at 200 Hz. The proposed localization method would be used for the position feedback control of untethered magnetic devices or robots for medical applications in the future.
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Causal Discovery Beyond Conditional Independences
University of Tübingen, Germany, October 2015 (phdthesis)
ei
Diversity of sharp wave-ripples in the CA1 of the macaque hippocampus and their brain wide signatures
Ramirez-Villegas, J. F., Logothetis, N. K., Besserve, M.
45th Annual Meeting of the Society for Neuroscience (Neuroscience 2015), October 2015 (poster)
ei
Gaussian Process Optimization for Self-Tuning Control
Polytechnic University of Catalonia (BarcelonaTech), October 2015 (mastersthesis)
am ics
The fertilized forests Decision Forest Library
Lassner, C., Lienhart, R.
In ACM Transactions on Multimedia (ACMMM) Open-source Software Competition, October 2015 (inproceedings)
Abstract
Since the introduction of Random Forests in the 80's they have been a frequently used statistical tool for a variety of machine learning tasks. Many different training algorithms and model adaptions demonstrate the versatility of the forests. This variety resulted in a fragmentation of research and code, since each adaption requires its own algorithms and representations. In 2011, Criminisi and Shotton developed a unifying Decision Forest model for many tasks. By identifying the reusable parts and specifying clear interfaces, we extend this approach to an object oriented representation and implementation. This has the great advantage that research on specific parts of the Decision Forest model can be done locally' by reusing well-tested and high-performance components. Our fertilized forests library is open source and easy to extend. It provides components allowing for parallelization up to node optimization level to exploit modern many core architectures. Additionally, the library provides consistent and easy-to-maintain interfaces to C++, Python and Matlab and offers cross-platform and cross-interface persistence.
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SMPL: A Skinned Multi-Person Linear Model
ACM Trans. Graphics (Proc. SIGGRAPH Asia), 34(6):248:1-248:16, ACM, New York, NY, October 2015 (article)
Abstract
We present a learned model of human body shape and pose-dependent shape variation that is more accurate than previous models and is compatible with existing graphics pipelines. Our Skinned Multi-Person Linear model (SMPL) is a skinned vertex-based model that accurately represents a wide variety of body shapes in natural human poses. The parameters of the model are learned from data including the rest pose template, blend weights, pose-dependent blend shapes, identity-dependent blend shapes, and a regressor from vertices to joint locations. Unlike previous models, the pose-dependent blend shapes are a linear function of the elements of the pose rotation matrices. This simple formulation enables training the entire model from a relatively large number of aligned 3D meshes of different people in different poses. We quantitatively evaluate variants of SMPL using linear or dual-quaternion blend skinning and show that both are more accurate than a Blend-SCAPE model trained on the same data. We also extend SMPL to realistically model dynamic soft-tissue deformations. Because it is based on blend skinning, SMPL is compatible with existing rendering engines and we make it available for research purposes.
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Noise masking of White’s illusion exposes the weakness of current spatial filtering models of lightness perception
Betz, T., Shapley, R. M., Wichmann, F. A., Maertens, M.
Journal of Vision, 15(14):1-17, October 2015 (article)
ei
Permutational Rademacher Complexity: a New Complexity Measure for Transductive Learning
Tolstikhin, I., Zhivotovskiy, N., Blanchard, G.
In Proceedings of the 26th International Conference on Algorithmic Learning Theory, 9355, pages: 209-223, Lecture Notes in Computer Science, (Editors: K. Chaudhuri, C. Gentile and S. Zilles), Springer, ALT, October 2015 (inproceedings)
ei
Proceedings of the 37th German Conference on Pattern Recognition
Gall, J., Gehler, P., Leibe, B.
Springer, German Conference on Pattern Recognition, October 2015 (proceedings)
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Towards Probabilistic Volumetric Reconstruction using Ray Potentials
(Best Paper Award)
In 3D Vision (3DV), 2015 3rd International Conference on, pages: 10-18, Lyon, October 2015 (inproceedings)
Abstract
This paper presents a novel probabilistic foundation for volumetric 3-d reconstruction. We formulate the problem as inference in a Markov random field, which accurately captures the dependencies between the occupancy and appearance of each voxel, given all input images. Our main contribution is an approximate highly parallelized discrete-continuous inference algorithm to compute the marginal distributions of each voxel's occupancy and appearance. In contrast to the MAP solution, marginals encode the underlying uncertainty and ambiguity in the reconstruction. Moreover, the proposed algorithm allows for a Bayes optimal prediction with respect to a natural reconstruction loss. We compare our method to two state-of-the-art volumetric reconstruction algorithms on three challenging aerial datasets with LIDAR ground truth. Our experiments demonstrate that the proposed algorithm compares favorably in terms of reconstruction accuracy and the ability to expose reconstruction uncertainty.
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Surgeons and Non-Surgeons Prefer Haptic Feedback of Instrument Vibrations During Robotic Surgery
Koehn, J. K., Kuchenbecker, K. J.
Surgical Endoscopy, 29(10):2970-2983, October 2015 (article)
hi
Displaying Sensed Tactile Cues with a Fingertip Haptic Device
Pacchierotti, C., Prattichizzo, D., Kuchenbecker, K. J.
IEEE Transactions on Haptics, 8(4):384-396, October 2015 (article)
hi
Causal Inference for Empirical Time Series Based on the Postulate of Independence of Cause and Mechanism
53rd Annual Allerton Conference on Communication, Control, and Computing, September 2015 (talk)
ei
From Points to Probability Measures: A Statistical Learning on Distributions with Kernel Mean Embedding
University of Tübingen, Germany, University of Tübingen, Germany, September 2015 (phdthesis)
ei
Machine Learning Approaches to Image Deconvolution
University of Tübingen, Germany, University of Tübingen, Germany, September 2015 (phdthesis)
ei
Compliant wing design for a flapping wing micro air vehicle
Colmenares, D., Kania, R., Zhang, W., Sitti, M.
In Intelligent Robots and Systems (IROS), 2015 IEEE/RSJ International Conference on, pages: 32-39, September 2015 (inproceedings)
Abstract
In this work, we examine several wing designs for a motor-driven, flapping-wing micro air vehicle capable of liftoff. The full system consists of two wings independently driven by geared pager motors that include a spring in parallel with the output shaft. The linear transmission allows for resonant operation, while control is achieved by direct drive of the wing angle. Wings used in previous work were chosen to be fully rigid for simplicity of modeling and fabrication. However, biological wings are highly flexible and other micro air vehicles have successfully utilized flexible wing structures for specialized tasks. The goal of our study is to determine if wing flexibility can be generally used to increase wing performance. Two approaches to lift improvement using flexible wings are explored, resonance of the wing cantilever structure and dynamic wing twisting. We design and test several wings that are compared using different figures of merit. A twisted design improved lift per power by 73.6% and maximum lift production by 53.2% compared to the original rigid design. Wing twist is then modeled in order to propose optimal wing twist profiles that can maximize either wing efficiency or lift production.
pi
Methods of forming dry adhesive structures
Sitti, M., Murphy, M., Aksak, B.
September 2015, US Patent 9,120,953 (patent)
Abstract
Methods of forming dry adhesives including a method of making a dry adhesive including applying a liquid polymer to the second end of the stem, molding the liquid polymer on the stem in a mold, wherein the mold includes a recess having a cross-sectional area that is less than a cross-sectional area of the second end of the stem, curing the liquid polymer in the mold to form a tip at the second end of the stem, wherein the tip includes a second layer stem; corresponding to the recess in the mold, and removing the tip from the mold after the liquid polymer cures.
pi
Stabilizing Novel Objects by Learning to Predict Tactile Slip
Veiga, F., van Hoof, H., Peters, J., Hermans, T.
In Proceedings of the IEEE/RSJ Conference on Intelligent Robots and Systems, pages: 5065-5072, IROS, September 2015 (inproceedings)
am ei
Moving-horizon Nonlinear Least Squares-based Multirobot Cooperative Perception
7th European Conference on Mobile Robots, pages: 1-8, September 2015 (conference)
Abstract
In this article we present an online estimator for multirobot cooperative localization and target tracking based on nonlinear least squares minimization. Our method not only makes the rigorous optimization-based approach applicable online but also allows the estimator to be stable and convergent. We do so by employing a moving horizon technique to nonlinear least squares minimization and a novel design of the arrival cost function that ensures stability and convergence of the estimator. Through an extensive set of real robot experiments, we demonstrate the robustness of our method as well as the optimality of the arrival cost function. The experiments include comparisons of our method with i) an extended Kalman filter-based online-estimator and ii) an offline-estimator based on full-trajectory nonlinear least squares.
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Millimeter-scale magnetic swimmers using elastomeric undulations
Zhang, J., Diller, E.
In 2015 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), pages: 1706-1711, September 2015 (inproceedings)
Abstract
This paper presents a new soft-bodied millimeterscale swimmer actuated by rotating uniform magnetic fields. The proposed swimmer moves through internal undulatory deformations, resulting from a magnetization profile programmed into its body. To understand the motion of the swimmer, a mathematical model is developed to describe the general relationship between the deflection of a flexible strip and its magnetization profile. As a special case, the situation of the swimmer on the water surface is analyzed and predictions made by the model are experimentally verified. Experimental results show the controllability of the proposed swimmer under a computer vision-based closed-loop controller. The swimmers have nominal dimensions of 1.5×4.9×0.06 mm and a top speed of 50 mm/s (10 body lengths per second). Waypoint following and multiagent control are demonstrated for swimmers constrained at the air-water interface and underwater swimming is also shown, suggesting the promising potential of this type of swimmer in biomedical and microfluidic applications.
pi
Shifts of Gamma Phase across Primary Visual Cortical Sites Reflect Dynamic Stimulus-Modulated Information Transfer
Besserve, M., Lowe, S. C., Logothetis, N. K., Schölkopf, B., Panzeri, S.
PLOS Biology, 13(9):e1002257, September 2015 (article)
ei
Model-Free Probabilistic Movement Primitives for Physical Interaction
Paraschos, A., Rueckert, E., Peters, J., Neumann, G.
In Proceedings of the IEEE/RSJ Conference on Intelligent Robots and Systems, pages: 2860-2866, IROS, September 2015 (inproceedings)
am ei
Combined Pose-Wrench and State Machine Representation for Modeling Robotic Assembly Skills
Wahrburg, A., Zeiss, S., Matthias, B., Peters, J., Ding, H.
In Proceedings of the IEEE/RSJ Conference on Intelligent Robots and Systems, pages: 852-857, IROS, September 2015 (inproceedings)
am ei
Perception of Strength and Power of Realistic Male Characters
Wellerdiek, A. C., Breidt, M., Geuss, M. N., Streuber, S., Kloos, U., Black, M. J., Mohler, B. J.
In Proc. ACM SIGGRAPH Symposium on Applied Perception, SAP’15, pages: 7-14, ACM, New York, NY, September 2015 (inproceedings)
Abstract
We investigated the influence of body shape and pose on the perception of physical strength and social power for male virtual characters. In the first experiment, participants judged the physical strength of varying body shapes, derived from a statistical 3D body model. Based on these ratings, we determined three body shapes (weak, average, and strong) and animated them with a set of power poses for the second experiment. Participants rated how strong or powerful they perceived virtual characters of varying body shapes that were displayed in different poses. Our results show that perception of physical strength was mainly driven by the shape of the body. However, the social attribute of power was influenced by an interaction between pose and shape. Specifically, the effect of pose on power ratings was greater for weak body shapes. These results demonstrate that a character with a weak shape can be perceived as more powerful when in a high-power pose.
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Probabilistic Progress Prediction and Sequencing of Concurrent Movement Primitives
Manschitz, S., Kober, J., Gienger, M., Peters, J.
In Proceedings of the IEEE/RSJ Conference on Intelligent Robots and Systems, pages: 449-455, IROS, September 2015 (inproceedings)
am ei
Reinforcement Learning vs Human Programming in Tetherball Robot Games
Parisi, S., Abdulsamad, H., Paraschos, A., Daniel, C., Peters, J.
In Proceedings of the IEEE/RSJ Conference on Intelligent Robots and Systems, pages: 6428-6434, IROS, September 2015 (inproceedings)
am ei
The EChemPen: A Guiding Hand To Learn Electrochemical Surface Modifications
Valetaud, M., Loget, G., Roche, J., Hueken, N., Fattah, Z., Badets, V., Fontaine, O., Zigah, D.
JOURNAL OF CHEMICAL EDUCATION, 92(10):1700-1704, September 2015 (article)
Abstract
The Electrochemical Pen (EChemPen) was developed as an attractive tool for learning electrochemistry. The fabrication, principle, and operation of the EChemPen are simple and can be easily performed by students in practical classes. It is based on a regular fountain pen principle, where the electrolytic solution is dispensed at a tip to locally modify a conductive surface by triggering a localized electrochemical reaction. Three simple model reactions were chosen to demonstrate the versatility of the EChemPen for teaching various electrochemical processes. We describe first the reversible writing/erasing of metal letters, then the electrodeposition of a black conducting polymer `ink{''}, and finally the colorful writings that can be generated by titanium anodization and that can be controlled by the applied potential. These entertaining and didactic experiments are adapted for teaching undergraduate students that start to study electrochemistry by means of surface modification reactions.
pf
Human Pose as Context for Object Detection
British Machine Vision Conference, British Machine Vision Conference, September 2015 (conference)
Abstract
Detecting small objects in images is a challenging problem particularly when they are often occluded by hands or other body parts. Recently, joint modelling of human pose and objects has been proposed to improve both pose estimation as well as object detection. These approaches, however, focus on explicit interaction with an object and lack the flexibility to combine both modalities when interaction is not obvious. We therefore propose to use human pose as an additional context information for object detection. To this end, we represent an object category by a tree model and train regression forests that localize parts of an object for each modality separately. Predictions of the two modalities are then combined to detect the bounding box of the object. We evaluate our approach on three challenging datasets which vary in the amount of object interactions and the quality of automatically extracted human poses.
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Active Learning for Efficient Sampling of Control Models of Collectives
Schiendorfer, A., Lassner, C., Anders, G., Reif, W., Lienhart, R.
In International Conference on Self-adaptive and Self-organizing Systems (SASO), September 2015 (inproceedings)
Abstract
Many large-scale systems benefit from an organizational structure to provide for problem decomposition. A pivotal problem solving setting is given by hierarchical control systems familiar from hierarchical task networks. If these structures can be modified autonomously by, e.g., coalition formation and reconfiguration, adequate decisions on higher levels require a faithful abstracted model of a collective of agents. An illustrative example is found in calculating schedules for a set of power plants organized in a hierarchy of Autonomous Virtual Power Plants. Functional dependencies over the combinatorial domain, such as the joint costs or rates of change of power production, are approximated by repeatedly sampling input-output pairs and substituting the actual functions by piecewise linear functions. However, if the sampled data points are weakly informative, the resulting abstracted high-level optimization introduces severe errors. Furthermore, obtaining additional point labels amounts to solving computationally hard optimization problems. Building on prior work, we propose to apply techniques from active learning to maximize the information gained by each additional point. Our results show that significantly better allocations in terms of cost-efficiency (up to 33.7 % reduction in costs in our case study) can be found with fewer but carefully selected sampling points using Decision Forests.
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Learning Motor Skills from Partially Observed Movements Executed at Different Speeds
Ewerton, M., Maeda, G., Peters, J., Neumann, G.
In Proceedings of the IEEE/RSJ Conference on Intelligent Robots and Systems, pages: 456-463, IROS, September 2015 (inproceedings)
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https://astarmathsandphysics.com/o-level-maths-notes/354-solving-trigonometric-equations.html | ## Solving Trigonometric Equations
The basicandcurves are given on the left below andon the right below:
– blueblack
We have typically to solve equations such as
1. We start by making cosx the subject:
2. We take the inverse cos:
Now is the tricky part. There is more than one solution forWe have found one. The other solutions are given by using the symmetry of the cosine graph. It is symmetric about 180 We are using degrees here. The solutions are
41.41, 360-41.41, 360+41.41, 720-41.41, 720+41.41, 1080-41.41, 1080+41.41 ....degrees
Example: Solve
Now we use the symmetry of the sin curve. The solutions are
17.46, 180-17.46, 360+17.46, 540-17.46, 720+17.46,900-17.46 ....degrees
Example: Solve
Now we we the property of the tan curve that it repeats every 180 degrees. The solutions are
60.26, 180+60.26, 360+60.26, 540+60.26, 720+60.26, 900+60.26.....degrees | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9870372414588928, "perplexity": 4090.8108788658305}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-30/segments/1563195527396.78/warc/CC-MAIN-20190721225759-20190722011759-00386.warc.gz"} |
http://www.soundigital.com.br/ | ## Representantes
Nossos Representantes estão a disposição para atender você, comprador ou lojista. Com conhecimento técnico e foco na sua necessidade, são extremamente capazes para te auxiliar.
REPRESENTANTES >
## Assistências
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January 1, 2030
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January 1, 2030
This is where the post content will show up. The font color, font size, line-height, and other styles related to the font, as well as stroke, corner radius and backgroung color / image can be styled. Simply use the text / color / stroke panel to style any of these elements! You can also change the spacing by clicking on the top right arrow near this field. Again this is a sample text and will be replaced with the content of each post. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8773987293243408, "perplexity": 8304.257752226904}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-39/segments/1505818691830.33/warc/CC-MAIN-20170925130433-20170925150433-00047.warc.gz"} |
https://pandas.pydata.org/pandas-docs/version/0.23.4/generated/pandas.DataFrame.plot.hist.html | # pandas.DataFrame.plot.hist¶
DataFrame.plot.hist(by=None, bins=10, **kwds)[source]
Draw one histogram of the DataFrame’s columns.
A histogram is a representation of the distribution of data. This function groups the values of all given Series in the DataFrame into bins and draws all bins in one matplotlib.axes.Axes. This is useful when the DataFrame’s Series are in a similar scale.
Parameters: by : str or sequence, optional Column in the DataFrame to group by. bins : int, default 10 Number of histogram bins to be used. **kwds Additional keyword arguments are documented in pandas.DataFrame.plot(). axes : matplotlib.AxesSubplot histogram.
DataFrame.hist
Draw histograms per DataFrame’s Series.
Series.hist
Draw a histogram with Series’ data.
Examples
When we draw a dice 6000 times, we expect to get each value around 1000 times. But when we draw two dices and sum the result, the distribution is going to be quite different. A histogram illustrates those distributions.
>>> df = pd.DataFrame(
... np.random.randint(1, 7, 6000),
... columns = ['one'])
>>> df['two'] = df['one'] + np.random.randint(1, 7, 6000)
>>> ax = df.plot.hist(bins=12, alpha=0.5)
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http://math.stackexchange.com/questions/391619/finite-ring-of-sets | # Finite ring of sets
I have some questions about finite rings of sets and I'll be very grateful for any help.
Let E be some fixed non-empty set. Suppose we are given some finite ring of subsets of set E, i.e. some non-empty system $S \subset E$ such that
$\forall A,B \in 2^E ~~ A \vartriangle B \in S$
$\forall A,B \in 2^E ~~ A \cap B \in S$
1) Does it necessarily have a unity? (or in more abstract form: is there necessarily a unity in the finite commutative ring in which multiplication is idempotent?)
2) Suppose we're given some finite system of subsets of E. Is there any algorithm for building the minimal ring of sets which contains this system? I know that from n sets using union, intersection and set difference we mat build at most $~2^{2^n}$ different sets so this ring must be finite.
3) If we know that S is a ring with unity (and so it's a boolean ring) how can we build an isomorphism from our ring of sets to some ring $B^n = (\{0,1\}^n, +, \cdot)$ where
$0 + 0 = 1 + 1 = 0$
$0 + 1 = 1 + 0 = 1$
$0 \cdot 1 = 0 \cdot 0 = 1 \cdot 0 = 0$
$1 \cdot 1 = 1$
-
– user26857 May 14 '13 at 17:24
@YACP I was just going to post the same reference :-) And I believe that my answer there covers both 1) and 3) – Andreas Caranti May 14 '13 at 17:25
Notice that $(A\vartriangle B)\vartriangle(A\cap B)=A\cup B$, so the ring actually contains finite unions of its members. Since the ring is finite, $E:=\cup S\in S$. Therefore, $E$ contains all members of $S$, and so $E\cap A=A$ for all $A$.
This also gives a partial start on item 2. Suppose that $G$ is a collection of sets that you want to generate a ring of sets with. Notice that both operations only produce sets which have elements in the two sets you started with. So, any set you generate will not escape $\cup G$. Then the generated ring is contained inside the powerset $\mathcal{P}(\cup G)$. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9470853209495544, "perplexity": 151.97612787906198}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-07/segments/1454701148475.34/warc/CC-MAIN-20160205193908-00070-ip-10-236-182-209.ec2.internal.warc.gz"} |
http://xxicla.dm.uba.ar/viewAbstract.php?code=1368 | Conference abstracts
Session S08 - Lie Groups and Representations
July 28, 15:40 ~ 16:20
## Representation ring of Levi subgroups versus cohomology ring of flag varieties
### University of North Carolina, Chapel Hill, USA - [email protected]
Recall the classical result that the cup product structure constants for the singular cohomology with integral coefficients of the Grassmannian of $r$-planes coincide with the Littlewood-Richardson tensor product structure constants for $GL(r)$. Specifically, the result asserts that there is an explicit ring homomorphism $\phi: \text{Rep}_{poly}(GL(r)) \to H^*(Gr(r, n))$, where $Gr(r, n)$ denotes the Grassmannian of $r$-planes in $\mathbb{C}^n$ and $\text{Rep}_{poly} (GL(r))$ denotes the polynomial representation ring of $GL(r)$.
This work seeks to achieve one possible generalization of this classical result for $GL(r)$ and the Grassmannian $Gr(r,n)$ to the Levi subgroups of any reductive group $G$ and the corresponding flag varieties. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8622463941574097, "perplexity": 294.33809513064915}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-47/segments/1542039743184.39/warc/CC-MAIN-20181116194306-20181116220306-00227.warc.gz"} |
https://math.stackexchange.com/questions/2435688/the-construction-of-closed-subscheme | # The construction of closed subscheme
Let $(\varphi,\varphi^{\sharp}):(X,\mathcal{O}_X)\to (Y,\mathcal{O}_Y)$ be a morphism of schemes.
Suppose $Y$ is covered by a family of affine open subschemes $\{U_i\}$ with $U_i=\mathrm{Spec} A_i$.
Consider $\varphi^{\sharp}(Y):\mathcal{O}_Y(Y)\to \mathcal{O}_X(X)$ and $\rho_{YU_i}:\mathcal O_Y(Y)\to A_i$. Let $S$ be a nonempty subset of $\ker(\varphi^{\sharp}(Y))$ and $\mathfrak p_i$ be the ideal of $A_i$ generated by $\rho_{YU_i}(S)$.
Given $f\in A_i,g\in A_j$, let $\mathfrak q_f$ be the ideal of $(A_i)_f$ generated by $\rho_{YD(f)}(S)$, and $\mathfrak p_j$ be the ideal of $A_j$ generated by $\rho_{YU_j}(S)$, and $\mathfrak q_g$ be the ideal of $(A_j)_g$ generated by $\rho_{YD(g)}(S)$. Then we
have the following two commutative diagrames:
$$\begin{array}[c]{ccc} A_i&{\rightarrow}&A_i/\mathfrak p_i\\ \downarrow&&\downarrow\\ (A_i)_f&{\rightarrow}&(A_i)_f/\mathfrak q_f \end{array}$$
$$\begin{array}[c]{ccc} A_j&{\rightarrow}&A_j/\mathfrak p_j\\ \downarrow&&\downarrow\\ (A_j)_g&{\rightarrow}&(A_j)_g/\mathfrak q_g \end{array}$$
We get two closed immersions $\psi_i:\mathrm{Spec}(A_i/\mathfrak p_i)\to \mathrm{Spec}A_i$ and $\psi_j:\mathrm{Spec}(A_j/\mathfrak p_j)\to \mathrm{Spec}A_j$.
Define $\lambda_i:(A_i/\mathfrak p_i)_{f+\mathfrak p_i}\to (A_i)_f/\mathfrak q_f$ as follows：
$\frac{a+\mathfrak p_i}{f^n+\mathfrak p_i}\mapsto \frac{a}{f^n}+\mathfrak q_f.$
If $\frac{a+\mathfrak p_i}{f^n+\mathfrak p_i}=\frac{b+\mathfrak p_i}{f^m+\mathfrak p_i},$
then there exists some $k\in \Bbb N$ such that $f^k(af^m-bf^n)\in\mathfrak p_i$,
we get $\frac{a}{f^n}+\mathfrak q_f=\frac{b}{f^m}+\mathfrak q_f$, so $\lambda_i$ is defined well.
Obviously $\lambda_i$ is surjective.
If $\frac{a}{f^n}+\mathfrak q_f=0$,then $\frac{a}{f^n}\in \mathfrak q_f, \frac{a}{1}\in \mathfrak q_f$,
we have
$\frac{a}{1}=\frac{x_1}{f^{n_1}}\frac{r_1}{1}+\frac{x_2}{f^{n_2}}\frac{r_2}{1}+\cdots+\frac{x_k}{f^{n_k}}\frac{r_k}{1}$ where $x_t\in A_i,r_t\in \rho_{YU_i}(S),1\le t\le k$.
Multiply both sides by $\frac{f^{n_1+n_2+\cdots+n_k}}{1}$, there exists some $h\in \Bbb N$ such that $af^h\in \mathfrak p_i$, so
$\frac{a+\mathfrak p_i}{f^n+\mathfrak p_i}=0$, and $\lambda_i$ is injective, therefore it is an isomorphism. In the same way we get that
$\lambda_j:(A_j/\mathfrak p_j)_{g+\mathfrak p_j}\to (A_j)_g/\mathfrak q_g$ is also an isomorphism.
We know that $U_i\cap U_j$ can be covered by a family of affine open subschemes $\{ W_{\alpha} \}$ of $Y$ such that
$W_{\alpha}=D(f_{\alpha})=D(g_{\alpha})$, where $f_{\alpha}\in A_i,g_{\alpha}\in A_j$.
Denote $Z_i=\mathrm{Spec}(A_i/\mathfrak p_i),Z_j=\mathrm{Spec}(A_j/\mathfrak p_j)$.
$\forall c\in W_{\alpha}$, if $\psi_i^{-1}(c)\neq \emptyset$, then $c\in \psi_i(Z_i)$, because $\lambda_i,\lambda_j$
are isomorpisms, we also have $c \in\psi_j(Z_j)$. We get $\chi_i:\psi_i^{-1}(U_i\cap U_j)\simeq \psi_i(Z_i)\cap \psi_j(Z_j),\chi_j: \psi_j^{-1}(U_i\cap U_j)\simeq \psi_i(Z_i)\cap \psi_j(Z_j)$ as homeomorphisms of topological spaces. Denote $Z_{ij}=\psi_i^{-1}(U_i\cap U_j), Z_{ji}=\psi_j^{-1}(U_i\cap U_j)$, $\xi_{ij}=\chi_j^{-1}\chi_i, \xi_{ji}=\chi_i^{-1}\chi_j$. Because $\lambda_i,\lambda_j$ are isomorpisms, $\xi_{ij}$ and $\xi_{ji}$ are isomorphisms of schemes，and $\xi_{ij}=\xi_{ji}^{-1}$.
Can we apply the Glueing Lemma to get a closed subscheme $Z$ of $Y$ and a closed immersion $(\mu,\mu^{\sharp}):(Z,\mathcal O_Z)\to (Y,\mathcal O_Y)$? Does there exist a morphism of schemes $(\nu,\nu^{\sharp}):(X,\mathcal O_X)\to (Z,\mathcal O_Z)$ such that $(\varphi,\varphi^{\sharp})=(\mu,\mu^{\sharp})(\nu,\nu^{\sharp})$? | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9930118918418884, "perplexity": 53.74603340616606}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-26/segments/1560627999800.5/warc/CC-MAIN-20190625051950-20190625073950-00208.warc.gz"} |
http://www.physicsforums.com/showthread.php?t=484519 | # PS and Jpg in Latex Files
by ed2288
Tags: jpeg, jpg, latex, postscript
P: 25 Hi everyone, I was wondering if someone could clarify how to put both .ps and .jpg files in the same latex file. At the minute I'm having to convert all my .jpgs to .ps using photoshop then compiling my latex file by going Latex->PS->PDF. However all my converted jpgs look all pixelated and frankly pretty rubbish. *Surely* there must be a way to include both .jpgs and .ps files, people need to do this all the time. When I try to include jpgs I get error messages saying no Bounding Box. Can anyone help me out? Thanks
Sci Advisor P: 1,724 When you say "include both .jpgs and .ps files" does that mean that you're actually using the \include function? If so, there's your problem: ps is postscript, which LaTeX will include in your actual document (it just so happens that your .ps codes for an image, so things happily chug along). If so, take a look at some of the examples here: http://en.wikibooks.org/wiki/LaTeX/I...ges_as_Figures Don't forget to \usepackage{graphicx}! If not, well, I've never run into that particular problem before--can you post the offending code?
P: 313 There's a program called ebb to Extract Bounding Boxes. It's easy to get for *nix http://linux.die.net/man/1/ebb And for windows is distributed with miktex. Here's a page with tips http://www.math.vanderbilt.edu/~sche...d/tips_pix.htm
PF Gold
P: 144
## PS and Jpg in Latex Files
Just want to post a quick thankyou to contributors in this thread. I've been having problems importing gifs into a pdf via latex and you have fixed my problem(s). I'm just converting jpgs to eps's and following what ed2288 and matlabdude suggest. The resultant image isn't perfect but is fit for purpose. Thanks.
Related Discussions Math & Science Software 9 Academic Guidance 5 Programming & Computer Science 3 Computing & Technology 2 | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9133977890014648, "perplexity": 4237.917325221757}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-15/segments/1397609532374.24/warc/CC-MAIN-20140416005212-00201-ip-10-147-4-33.ec2.internal.warc.gz"} |
https://mathoverflow.net/questions/181931/on-a-property-of-the-grothendieck-group-of-a-smooth-projective-curve | # On a property of the Grothendieck group of a smooth projective curve
Let $K$ be a complete DVR of characteristic $0$, $X$ a smooth projective curve over $K$. Denote by $K^0(X)$ the Grothendieck group of locally free sheaves on $X$ and by $\mbox{det}$ the natural group homomorphism from $K^0(X)$ to $\mbox{Pic}(X)$. Suppose that for some $L \in \mbox{Pic}(X)$, there exists $[V] \in K^0(X)$ such that $\mbox{det}([V])=L$. Let $L'$ be another line bundle on $X$ of the same degree as $L$. The question is, does there exist $[V'] \in K^0(X)$ such that $V'$ is of the same rank and degree as $V$ and $\mbox{det}([V'])=L'$? If not true in general, is there any known condition/example of $K$ (other than algebraic closedness in which case the answer is known to be true via twisting $V$ by a suitable line bundle), for example if $K$ is a $C_1$-field under which we have a positive answer to the question?
• Are we allowed to set $V' = L'$? – S. Carnahan Sep 27 '14 at 13:47
• @Carnahan: Sorry. No, we need $V'$ to have the same rank and degree as $V$. I will edit the question. – user43198 Sep 27 '14 at 13:49
Perhaps I am misunderstanding the question, but it seems to me that $\text{deg}(V)=\text{deg}(\text{det}(V))=\text{deg}(L)$, so we are just asking if for each $n$ there is a (virtual) vector bundle $[V']$ of rank $n$ and degree $\text{deg}(L')$. But $\mathcal{O}_X^{\oplus(n-1)}\oplus L'$ works, right? | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9764226675033569, "perplexity": 54.18290063635328}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-51/segments/1575540506459.47/warc/CC-MAIN-20191208044407-20191208072407-00120.warc.gz"} |
https://pennstate.pure.elsevier.com/en/publications/network-coded-cooperation-over-time-varying-channels | Network-coded cooperation over time-varying channels
Hana Khamfroush, Daniel E. Lucani, Joao Barros, Peyman Pahlevani
Research output: Contribution to journalArticlepeer-review
2 Scopus citations
Abstract
In this paper, we investigate the optimal design of cooperative network-coded strategies for a three-node wireless network with time-varying half-duplex erasure channels. To this end, we formulate the problem of minimizing the total cost of transmitting $M$ packets from source to two receivers as a Markov decision process (MDP). The actions of the MDP model include the source and the type of transmission to be used in a given time slot given perfect knowledge of the system state. The cost of packet transmission is defined such that it can incorporate the difference between broadcast and unicast transmissions, e.g., in terms of the rate of packet transmission or the energy consumption. A comprehensive analysis of the MDP solution is carried out under different network conditions to extract optimal rules of packet transmission. Inspired by the extracted rules, we propose two near-optimal heuristics that are suitable for practical systems. We use two wireless channel models to analyze the performance of the proposed heuristics in practical wireless networks, namely, 1) an infrastructure-to-vehicle communication in a highway scenario considering Rayleigh fading and 2) real packet loss measurements for WiFi using Aalborg University's Raspberry Pi testbed. We compare our results with random linear network coding broadcasting schemes showing that our heuristics can provide up to 2 $\times$ gains in completion time and up to 4 $\times$ gains in terms of reliably serviced data packets.
Original language English (US) 6945883 4413-4425 13 IEEE Transactions on Communications 62 12 https://doi.org/10.1109/TCOMM.2014.2367016 Published - Dec 1 2014
All Science Journal Classification (ASJC) codes
• Electrical and Electronic Engineering
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https://www.physicsforums.com/threads/the-geometric-interpretation-of-a-set.901905/ | # The geometric interpretation of a set
Tags:
1. Jan 28, 2017
### Sho Kano
1. The problem statement, all variables and given/known data
Show the geometric interpretation of S is a plane in $R^3$ and find its equation
$S=\left\{ (a+b,2b,-a)\in { R }^{ 3 }|a,b\in R \right\}$
2. Relevant equations
3. The attempt at a solution
I know that S is the set of all points that lie in a plane, but have no idea where to go from there
Can you offer guidance or do you also need help?
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https://socratic.org/questions/how-do-you-evaluate-abs-41-abs18-12 | Prealgebra
Questions Topics
# How do you evaluate abs(-41)-abs18+12?
Then teach the underlying concepts
Don't copy without citing sources
preview
?
#### Explanation
Explain in detail...
#### Explanation:
I want someone to double check my answer
1
Alex K. Share
Nov 30, 2016
41 - 18 + 12 = 35
#### Explanation:
The absolute value of -41 is 41, and +18 is still 18.
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https://edwiv.com/archives/1096 | # Codeforces Round #597 (Div. 2)
## A. Good ol' Numbers Coloring
time limit per test1 second memory limit per test256 megabytes
Consider the set of all nonnegative integers: $${0, 1, 2, \dots}$$. Given two integers a and b $$(1 \le a, b \le 10^4)$$. We paint all the numbers in increasing number first we paint 0, then we paint 1, then 2 and so on.
Each number is painted white or black. We paint a number i according to the following rules:
• if i = 0, it is colored white;
• if $$i \ge a$$ and i - a is colored white, i is also colored white;
• if $$i \ge b$$ and i - b is colored white, i is also colored white;
• if i is still not colored white, it is colored black.
In this way, each nonnegative integer gets one of two colors.
For example, if a=3, b=5, then the colors of the numbers (in the order from 0) are: white (0), black (1), black (2), white (3), black (4), white (5), white (6), black (7), white (8), white (9), ...
Note that:
• It is possible that there are infinitely many nonnegative integers colored black. For example, if a = 10 and b = 10, then only 0, 10, 20, 30 and any other nonnegative integers that end in 0 when written in base 10 are white. The other integers are colored black.
• It is also possible that there are only finitely many nonnegative integers colored black. For example, when a = 1 and b = 10, then there is no nonnegative integer colored black at all.
Your task is to determine whether or not the number of nonnegative integers colored black is infinite.
If there are infinitely many nonnegative integers colored black, simply print a line containing "Infinite" (without the quotes). Otherwise, print "Finite" (without the quotes).
Input
The first line of input contains a single integer t $$(1 \le t \le 100)$$ — the number of test cases in the input. Then t lines follow, each line contains two space-separated integers a and b $$(1 \le a, b \le 10^4)$$.
Output
For each test case, print one line containing either "Infinite" or "Finite" (without the quotes). Output is case-insensitive (i.e. "infinite", "inFiNite" or "finiTE" are all valid answers).
Exampleinput
4
10 10
1 10
6 9
7 3
output
Infinite
Finite
Infinite
Finite
#### 签到，互质即可
#include<bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for(int i=(a);i<=(b);++i)
#define dep(i,a,b) for(int i=(a);i>=(b);--i)
#define pb push_back
typedef long long ll;
const int maxn=(int)2e5+100;
const int mod=(int)1e9+7;
int gcd(int a,int b){return b?gcd(b,a%b):a;}
void solve(){
int a,b;cin>>a>>b;
if(gcd(a,b)==1) puts("finite");
else puts("inFinite");
}
int main(){
int T;cin>>T;
while(T--) solve();
}
## B. Restricted RPS
time limit per test1 second memory limit per test256 megabytes
Let n be a positive integer. Let a, b, c be nonnegative integers such that a + b + c = n.
Alice and Bob are gonna play rock-paper-scissors n times. Alice knows the sequences of hands that Bob will play. However, Alice has to play rock a times, paper b times, and scissors c times.
Alice wins if she beats Bob in at least $$\lceil \frac{n}{2} \rceil (\frac{n}{2}$$ rounded up to the nearest integer) hands, otherwise Alice loses.
Note that in rock-paper-scissors:
• rock beats scissors;
• paper beats rock;
• scissors beat paper.
The task is, given the sequence of hands that Bob will play, and the numbers a, b, c, determine whether or not Alice can win. And if so, find any possible sequence of hands that Alice can use to win.
If there are multiple answers, print any of them.Input
The first line contains a single integer t $$(1 \le t \le 100)$$ — the number of test cases.
Then, t testcases follow, each consisting of three lines:
• The first line contains a single integer n $$(1 \le n \le 100)$$.
• The second line contains three integers, a, b, c $$(0 \le a, b, c \le n)$$. It is guaranteed that a + b + c = n.
• The third line contains a string s of length n. s is made up of only 'R', 'P', and 'S'. The i-th character is 'R' if for his i-th Bob plays rock, 'P' if paper, and 'S' if scissors.
Output
For each testcase:
• If Alice cannot win, print "NO" (without the quotes).
• Otherwise, print "YES" (without the quotes). Also, print a string t of length n made up of only 'R', 'P', and 'S' — a sequence of hands that Alice can use to win. t must contain exactly a 'R's, b 'P's, and c 'S's.
• If there are multiple answers, print any of them.
The "YES" / "NO" part of the output is case-insensitive (i.e. "yEs", "no" or "YEs" are all valid answers). Note that 'R', 'P' and 'S' are case-sensitive.
Exampleinput
2
3
1 1 1
RPS
3
3 0 0
RPS
output
YES
PSR
NO
Note
In the first testcase, in the first hand, Alice plays paper and Bob plays rock, so Alice beats Bob. In the second hand, Alice plays scissors and Bob plays paper, so Alice beats Bob. In the third hand, Alice plays rock and Bob plays scissors, so Alice beats Bob. Alice beat Bob 3 times, and $$3 \ge \lceil \frac{3}{2} \rceil = 2$$, so Alice wins.
In the second testcase, the only sequence of hands that Alice can play is "RRR". Alice beats Bob only in the last hand, so Alice can't win. $$1 < \lceil \frac{3}{2} \rceil = 2$$.
#### 签到，模拟即可
#include<bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for(int i=(a);i<=(b);++i)
#define dep(i,a,b) for(int i=(a);i>=(b);--i)
#define pb push_back
typedef long long ll;
const int maxn=(int)2e5+100;
const int mod=(int)1e9+7;
int n,a,b,c,pos,cnt;
char s[maxn],ans[110];
void solve(){
pos=0;cnt=0;
scanf("%d",&n);
cin>>a>>b>>c;
scanf("%s",s+1);
int aa=0,bb=0,cc=0;
rep(i,1,n){
if(s[i]=='R') bb++;
if(s[i]=='P') cc++;
if(s[i]=='S') aa++;
ans[i]='*';
}
if(min(a,aa)+min(b,bb)+min(c,cc)>=(n+1)/2){
puts("YES");
rep(i,1,n){
if(s[i]=='R'&&b) b--,ans[i]='P';
if(s[i]=='P'&&c) c--,ans[i]='S';
if(s[i]=='S'&&a) a--,ans[i]='R';
}
rep(i,1,n){
if(ans[i]!='*') printf("%c",ans[i]);
else if(a) a--,printf("R");
else if(b) b--,printf("P");
else c--,printf("S");
}
puts("");
}
else puts("NO");
}
int main(){
int T;cin>>T;
while(T--) solve();
}
## C. Constanze's Machine
time limit per test1 second memory limit per test256 megabytes
Constanze is the smartest girl in her village but she has bad eyesight.
One day, she was able to invent an incredible machine! When you pronounce letters, the machine will inscribe them onto a piece of paper. For example, if you pronounce 'c', 'o', 'd', and 'e' in that order, then the machine will inscribe "code" onto the paper. Thanks to this machine, she can finally write messages without using her glasses.
However, her dumb friend Akko decided to play a prank on her. Akko tinkered with the machine so that if you pronounce 'w', it will inscribe "uu" instead of "w", and if you pronounce 'm', it will inscribe "nn" instead of "m"! Since Constanze had bad eyesight, she was not able to realize what Akko did.
The rest of the letters behave the same as before: if you pronounce any letter besides 'w' and 'm', the machine will just inscribe it onto a piece of paper.
The next day, I received a letter in my mailbox. I can't understand it so I think it's either just some gibberish from Akko, or Constanze made it using her machine. But since I know what Akko did, I can just list down all possible strings that Constanze's machine would have turned into the message I got and see if anything makes sense.
But I need to know how much paper I will need, and that's why I'm asking you for help. Tell me the number of strings that Constanze's machine would've turned into the message I got.
But since this number can be quite large, tell me instead its remainder when divided by $$10^9+7$$.
If there are no strings that Constanze's machine would've turned into the message I got, then print 0.
Input
Input consists of a single line containing a string s $$(1 \leq |s| \leq 10^5)$$ — the received message. s contains only lowercase Latin letters.
Output
Print a single integer — the number of strings that Constanze's machine would've turned into the message s, modulo $$10^9+7$$.
Examplesinput
ouuokarinn
output
4
input
banana
output
1
input
nnn
output
3
input
amanda
output
0
Note
For the first example, the candidate strings are the following: "ouuokarinn", "ouuokarim", "owokarim", and "owokarinn".
For the second example, there is only one: "banana".
For the third example, the candidate strings are the following: "nm", "mn" and "nnn".
For the last example, there are no candidate strings that the machine can turn into "amanda", since the machine won't inscribe 'm'.
#### 斐波那契乘一下就好啦
#include<bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for(int i=(a);i<=(b);++i)
#define dep(i,a,b) for(int i=(a);i>=(b);--i)
#define pb push_back
typedef long long ll;
const int maxn=(int)1e5+100;
const int mod=(int)1e9+7;
ll f[maxn];
int ans=1;
char s[maxn];
int main(){
f[2]=2;f[3]=3;
scanf("%s",s+1);
int n=strlen(s+1),cnt=1;
rep(i,4,n) f[i]=(f[i-1]+f[i-2])%mod;
rep(i,1,n) if(s[i]=='m'||s[i]=='w') return puts("0"),0;
char pre=s[1];s[n+1]='*';n++;
rep(i,2,n){
if(s[i]==pre) cnt++;
else{
if((pre=='u'||pre=='n')&&cnt>1) ans=ans*f[cnt]%mod;
cnt=1;
}
pre=s[i];
}
printf("%d\n",ans);
}
## D. Shichikuji and Power Grid
time limit per test2 seconds memory limit per test256 megabytes
Shichikuji is the new resident deity of the South Black Snail Temple. Her first job is as follows:
There are n new cities located in Prefecture X. Cities are numbered from 1 to n. City i is located $$x_i$$ km North of the shrine and $$y_i$$ km East of the shrine. It is possible that $$(x_i, y_i) = (x_j, y_j)$$ even when $$i \ne j$$.
Shichikuji must provide electricity to each city either by building a power station in that city, or by making a connection between that city and another one that already has electricity. So the City has electricity if it has a power station in it or it is connected to a City which has electricity by a direct connection or via a chain of connections.
• Building a power station in City i will cost $$c_i$$ yen;
• Making a connection between City i and City j will cost $$k_i + k_j$$ yen per km of wire used for the connection. However, wires can only go the cardinal directions (North, South, East, West). Wires can cross each other. Each wire must have both of its endpoints in some cities. If City i and City j are connected by a wire, the wire will go through any shortest path from City i to City j. Thus, the length of the wire if City i and City j are connected is $$|x_i - x_j| + |y_i - y_j|$$ km.
Shichikuji wants to do this job spending as little money as possible, since according to her, there isn't really anything else in the world other than money. However, she died when she was only in fifth grade so she is not smart enough for this. And thus, the new resident deity asks for your help.
And so, you have to provide Shichikuji with the following information: minimum amount of yen needed to provide electricity to all cities, the cities in which power stations will be built, and the connections to be made.
If there are multiple ways to choose the cities and the connections to obtain the construction of minimum price, then print any of them.
Input
First line of input contains a single integer n $$(1 \leq n \leq 2000)$$ — the number of cities.
Then, n lines follow. The i-th line contains two space-separated integers $$x_i (1 \leq x_i \leq 10^6)$$ and$$y_i (1 \leq y_i \leq 10^6)$$ — the coordinates of the i-th city.
The next line contains n space-separated integers $$c_1, c_2, \dots, c_n (1 \leq c_i \leq 10^9)$$ — the cost of building a power station in the i-th city.
The last line contains n space-separated integers $$k_1, k_2, \dots, k_n (1 \leq k_i \leq 10^9)$$.
Output
In the first line print a single integer, denoting the minimum amount of yen needed.
Then, print an integer v — the number of power stations to be built.
Next, print v space-separated integers, denoting the indices of cities in which a power station will be built. Each number should be from 1 to n and all numbers should be pairwise distinct. You can print the numbers in arbitrary order.
After that, print an integer e — the number of connections to be made.
Finally, print e pairs of integers a and b $$(1 \le a, b \le n, a \ne b)$$, denoting that a connection between City a and City b will be made. Each unordered pair of cities should be included at most once (for each (a, b) there should be no more (a, b) or (b, a) pairs). You can print the pairs in arbitrary order.
If there are multiple ways to choose the cities and the connections to obtain the construction of minimum price, then print any of them.
Examplesinput
3
2 3
1 1
3 2
3 2 3
3 2 3
output
8
3
1 2 3
0
input
3
2 1
1 2
3 3
23 2 23
3 2 3
output
27
1
2
2
1 2
2 3
Note
For the answers given in the samples, refer to the following diagrams (cities with power stations are colored green, other cities are colored blue, and wires are colored red):
For the first example, the cost of building power stations in all cities is 3 + 2 + 3 = 8. It can be shown that no configuration costs less than 8 yen.
For the second example, the cost of building a power station in City 2 is 2. The cost of connecting City 1 and City 2 is $$2 \cdot (3 + 2) = 10$$. The cost of connecting City 2 and City 3 is $$3 \cdot (2 + 3) = 15$$. Thus the total cost is 2 + 10 + 15 = 27. It can be shown that no configuration costs less than 27 yen.
#### 最小生成树裸题
#include<bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for(ll i=(a);i<=(b);++i)
#define dep(i,a,b) for(ll i=(a);i>=(b);--i)
#define pb push_back
typedef long long ll;
const ll maxn=(ll)1e6+100;
const ll mod=(ll)1e9+7;
ll n,x[maxn],y[maxn],c[maxn],k[maxn],pre[maxn];
ll find(ll x){return pre[x]==x?x:pre[x]=find(pre[x]);}
struct edge{
ll u,v,w;
bool operator<(edge b)const{return w<b.w;}
}e[maxn<<2];
ll fun(ll i,ll j){return (k[i]+k[j])*(abs(x[i]-x[j])+abs(y[i]-y[j]));}
int main(){
scanf("%lld",&n);
rep(i,1,n) pre[i]=i;
rep(i,1,n) scanf("%lld%lld",&x[i],&y[i]);
rep(i,1,n) scanf("%lld",&c[i]);
rep(i,1,n) scanf("%lld",&k[i]);
ll pos=0,ans=0;
vector<ll> vec,eg;
rep(i,1,n) e[++pos]={0,i,c[i]};
rep(i,1,n) rep(j,i+1,n) e[++pos]={i,j,fun(i,j)};
sort(e+1,e+1+pos);
rep(i,1,pos){
ll u=find(e[i].u),v=find(e[i].v);
if(u!=v){
ans+=e[i].w;
if(e[i].u==0||e[i].v==0) vec.pb(max(e[i].u,e[i].v));
else eg.pb(i);
pre[u]=v;
}
}
printf("%lld\n%d\n",ans,(int)vec.size());
for(auto u:vec) printf("%lld ",u);
printf("\n%d\n",(int)eg.size());
for(auto u:eg) printf("%lld %lld\n",e[u].u,e[u].v);
}
time limit per test1 second memory limit per test256 megabytes
Hyakugoku has just retired from being the resident deity of the South Black Snail Temple in order to pursue her dream of becoming a cartoonist. She spent six months in that temple just playing "Cat's Cradle" so now she wants to try a different game — "Snakes and Ladders". Unfortunately, she already killed all the snakes, so there are only ladders left now.
The game is played on a $$10 \times 10$$ board as follows:
• At the beginning of the game, the player is at the bottom left square.
• The objective of the game is for the player to reach the Goal (the top left square) by following the path and climbing vertical ladders. Once the player reaches the Goal, the game ends.
• The path is as follows: if a square is not the end of its row, it leads to the square next to it along the direction of its row; if a square is the end of its row, it leads to the square above it. The direction of a row is determined as follows: the direction of the bottom row is to the right; the direction of any other row is opposite the direction of the row below it. See Notes section for visualization of path.
• During each turn, the player rolls a standard six-sided dice. Suppose that the number shown on the dice is r. If the Goal is less than r squares away on the path, the player doesn't move (but the turn is performed). Otherwise, the player advances exactly r squares along the path and then stops. If the player stops on a square with the bottom of a ladder, the player chooses whether or not to climb up that ladder. If she chooses not to climb, then she stays in that square for the beginning of the next turn.
• The numbers on the faces of the dice are 1, 2, 3, 4, 5, and 6, with each number having the same probability of being shown.
• it is possible for ladders to overlap, but the player cannot switch to the other ladder while in the middle of climbing the first one;
• it is possible for ladders to go straight to the top row, but not any higher;
• it is possible for two ladders to lead to the same tile;
• it is possible for a ladder to lead to a tile that also has a ladder, but the player will not be able to use that second ladder if she uses the first one;
• the player can only climb up ladders, not climb down.
Hyakugoku wants to finish the game as soon as possible. Thus, on each turn she chooses whether to climb the ladder or not optimally. Help her to determine the minimum expected number of turns the game will take.Input
Input will consist of ten lines. The i-th line will contain 10 non-negative integers $$h_{i1}, h_{i2}, \dots, h_{i10}$$. If $$h_{ij}$$ is 0, then the tile at the i-th row and j-th column has no ladder. Otherwise, the ladder at that tile will have a height of $$h_{ij}$$, i.e. climbing it will lead to the tile $$h_{ij}$$ rows directly above. It is guaranteed that $$0 \leq h_{ij} < i$$. Also, the first number of the first line and the first number of the last line always contain 0, i.e. the Goal and the starting tile never have ladders.Output
Print only one line containing a single floating-point number — the minimum expected number of turns Hyakugoku can take to finish the game. Your answer will be considered correct if its absolute or relative error does not exceed $$10^{-6}$$.
Examplesinput
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
output
33.0476190476
input
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 3 0 0 0 4 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 4 0 0 0
0 0 3 0 0 0 0 0 0 0
0 0 4 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 9
output
20.2591405923
input
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 6 6 6 6 6 6 0 0 0
1 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
output
15.9047592939
Note
A visualization of the path and the board from example 2 is as follows:
The tile with an 'S' is the starting tile and the tile with an 'E' is the Goal.
For the first example, there are no ladders.
For the second example, the board looks like the one in the right part of the image (the ladders have been colored for clarity).
#### 概率DP，先将每个点从终点开始编号，令$$dp[i]$$表示从i号点到终点的最小期望，显然$$dp[1]=0$$;如果不考虑梯子和终点的限制，那么$$dp[x]=\frac{\sum_{i=1}^{6}dp[x-i]}{6}+1$$;对于$$x<=6$$的情况需要特殊考虑，我们发现对于$$x=2$$，我们有$$\frac{5}{6}$$的概率不走，有$$\frac{1}{6}$$的概率走到终点，即$$dp[2]=\frac{5(dp[2]+1)}{6}+\frac{dp[1]+1}{6}$$；移项之后就是$$dp[2]=\frac{(\frac{5}{6}+\frac{dp[1]+1}{6})} { (1-\frac{5}{6})}$$；同理，$$dp[3]=\frac{(\frac{4}{6}+\frac{dp[1]+1}{6}+\frac{dp[2]+1}{6})}{(1-\frac{4}{6})}$$；于是我们得到对于$$x\in [2,6]$$，我们有$$dp[x]=\frac{\frac{(\sum_{i=1}^{x-1}dp[x-i]+1)}{6}+\frac{(7-i)}{6}}{1-\frac{(7-i)}{6}}$$；然后考虑加上梯子的情况，假设有一个梯子使得点x移动到y，那么$$dp[y]$$再考虑过一个从$$dp[x]$$转移来的情况就好了；
#include<bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for(int i=(a);i<=(b);++i)
#define dep(i,a,b) for(int i=(a);i>=(b);--i)
#define pb push_back
typedef long long ll;
const int maxn=(int)2e5+100;
const int mod=(int)1e9+7;
int id[110][110],to[110];
double dp[110];
int main(){
int tot=0;
rep(i,1,10){
if(i&1) rep(j,1,10) id[i][j]=++tot;
else dep(j,10,1) id[i][j]=++tot;
}
rep(i,1,10) rep(j,1,10){
int x;scanf("%d",&x);
if(x) to[id[i][j]]=id[i-x][j];
}
rep(i,2,6){//预处理x<6的情况
rep(j,1,i-1) dp[i]+=(dp[i-j]+1.0)/6;
dp[i]=(dp[i]+(7.0-i)/6)/(1.0-(7.0-i)/6);
}
rep(i,7,tot){
rep(j,1,6) dp[i]+=(dp[i-j]+1.0)/6;
if(!to[i]) continue;
double tmp=0;
if(to[i]==1){dp[i]=0;continue;}
rep(j,1,6) if(to[i]-j>0) tmp+=(dp[to[i]-j]+1.0)/6;
if(to[i]<=6) tmp+=(7.0-to[i])/6,tmp/=(1.0-(7.0-to[i])/6);
dp[i]=min(dp[i],tmp);
}
printf("%.10f\n",dp[tot]);
}
## F. Daniel and Spring Cleaning
time limit per test2 seconds memory limit per test256 megabytes
While doing some spring cleaning, Daniel found an old calculator that he loves so much. However, it seems like it is broken. When he tries to compute 1 + 3 using the calculator, he gets 2 instead of 4. But when he tries computing 1 + 4, he gets the correct answer, 5. Puzzled by this mystery, he opened up his calculator and found the answer to the riddle: the full adders became half adders!
So, when he tries to compute the sum a + b using the calculator, he instead gets the xorsum $$a \oplus b$$ (read the definition by the link: https://en.wikipedia.org/wiki/Exclusive_or).
As he saw earlier, the calculator sometimes gives the correct answer. And so, he wonders, given integers l and r, how many pairs of integers (a, b) satisfy the following conditions:
$$a + b = a \oplus b$$ $$l \leq a \leq r$$ $$l \leq b \leq r$$
However, Daniel the Barman is going to the bar and will return in two hours. He tells you to solve the problem before he returns, or else you will have to enjoy being blocked.
Input
The first line contains a single integer t $$(1 \le t \le 100)$$ — the number of testcases.
Then, t lines follow, each containing two space-separated integers l and r $$(0 \le l \le r \le 10^9)$$.
Output
Print t integers, the i-th integer should be the answer to the i-th testcase.
Exampleinput
3
1 4
323 323
1 1000000
output
8
0
3439863766
Note
$$a \oplus b$$ denotes the bitwise XOR of a and b.
For the first testcase, the pairs are: (1, 2), (1, 4), (2, 1), (2, 4), (3, 4), (4, 1), (4, 2), and (4, 3).
#### 首先将$$a + b = a \oplus b$$转换为$$a\&b==0$$，证明很好证，异或其实就是不进位的减法，那一加一减相等那肯定只有两个数对应的二进制都不同为1的情况才可以；接下来考虑一个容斥，令f(l,r)表示$$a \in [1,l] ,b \in [1,r]$$时的答案，那么最终答案显然就是$$f(l-1,l-1)+f(r,r)-2*f(l-1,r)$$接下来就是正常的数位DP，没什么好说的
#include<bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for(int i=(a);i<=(b);++i)
#define dep(i,a,b) for(int i=(a);i>=(b);--i)
#define pb push_back
typedef long long ll;
const int maxn=(int)2e5+100;
ll dp[40][2][2];
ll dfs(int l,int r,int pos,int lima,int limb){
if(pos<0) return 1;
if(dp[pos][lima][limb]!=-1) return dp[pos][lima][limb];
int ma=lima?((l>>pos)&1):1;
int mb=limb?((r>>pos)&1):1;
dp[pos][lima][limb]=0;
rep(i,0,ma) rep(j,0,mb) if((i&j)==0)
dp[pos][lima][limb]+=dfs(l,r,pos-1,lima&(i==ma),limb&(j==mb));
return dp[pos][lima][limb];
}
ll f(int l,int r){//a->[0,l],b->[0,r]，a&b==0的数量
if(l<0) return 0;
memset(dp,-1,sizeof(dp));
return dfs(l,r,log2(r+1),1,1);
}
void solve(){
int l,r;scanf("%d%d",&l,&r);
printf("%lld\n",f(l-1,l-1)+f(r,r)-2ll*f(l-1,r));
}
int main(){
int T;cin>>T;
while(T--) solve();
}
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https://ilovephilosophy.com/viewtopic.php?p=2724653 | ## Question for those in charge of hiring employees
For discussions of culture, politics, economics, sociology, law, business and any other topic that falls under the social science remit.
### Re: Question for those in charge of hiring employees
Carleas wrote:
Serendipper wrote:But if not for other alternatives (ie welfare or rich parents), then automation and general population expansion creates a glut of workers competing for the cheapest wage. So in this case, a free market in workers works to the detriment of society by keeping wages cheap and restraining incentive to increase efficiency.
I basically agree with this. The market price of human labor will go to zero over time. It's already happening in low-skill industries, and it's going to happen everywhere this century. It's a problem that needs to be addressed (my preferred solution is a Basic Income pegged to revenue from Value Added and Land Value taxes).
Yes UBI is the most sensible solution since then no one is forced to work for the profit of another in order to survive and we could then assume that all work is voluntary. Wages could be regulated by the amount of UBI, antiquating min wage laws. UBI should be the amount of money required to at least live a meager existence or else it wouldn't fulfill its purpose of making all work voluntary.
Serendipper wrote:it's addressing the "taxation is theft" argument
OK. I'm not making this argument, and it's not inherent in capitalism.
Only the capitalists make that argument. I don't see many socialists hollering taxation is theft lol. It's only the pirates proclaiming pirated loot is proprietary.
Serendipper wrote:Now if the person were made aware of the productivity split and agreed to the division...
So maybe the appropriate alternative question is for the employer to ask the employee to provide an accounting of her expenses: if it only costs you $300 per week to survive, and your work is worth$400 a week to me, let's split the difference at 350. But that's still leveraging someone's dire predicament against them which is exploitation. I mean, companies have recent begun hiring felons and druggies in order to escape raising the wage to attract quality employees. They are using someone's situation as leverage to minimize wages. A guy I know working for a Berkshire company said there are 30 jobs open perpetually that pay almost twice the minimum wage. I say raise the wage and people will stick. Instead of doing that, he'd rather characterize the people as lazy bums who won't knuckle-down and work for the peanuts he's offering. And that same company has stopped drug testing in order to hold wages down. "What??? No one will hire you because you're a crackhead??? What fortuitous circumstance be this; no one will work for me because I'm a greedy prick! Welcome aboard!" I agree that seems absurd. Similarly, it seems absurd for an employee to expect that they can get an accounting of what will be done with the value of their labor as part of negotiating their pay, or to hold that the only way to reach a fair, non-theft, non-exploitation agreement is for both parties to provide this information. Yes it's unrealistic, but my point isn't to fix the system, but illustrate what's going on and how the rich are getting that way. Serendipper wrote:But the exploited work says, "That SOB took advantage of the fact that I have no other options and he exploited me!" The fraud victim says "That SOB took advantage of the fact that I'm ignorant and he capitalized on that." The rape victim says "That SOB took advantage of the fact that I'm defenseless and he capitalized on that." There isn't much difference. One pretty significant difference is that the employer made her 'victim' better off. They may have accepted out of desperation, but they would have been worse off if they hadn't accepted (indeed, that's the premise of accepting our of desperation). The same isn't true of being defrauded or raped. I suppose that's true. I paid a fair wage and workers were better off working for me than not, but it still wasn't right, evidenced by the fact that I had to hide what I made and pretend I was just as poor as they were. Serendipper wrote:If an employee really had a share of the profit, they'd be motivated to find ways to increase it instead of acting like lazy bums riding the clock. That's why employers offer it, particularly to people whose labor has a significant effect on total output (e.g. management and executives). Management and executives are the ones overpaid to start with. They don't do anything commensurate with their pay which is a disservice to shareholders and society. For low-skilled labor, there are game theoretic limitations on how much it can motivate. One of ten thousand people on an assembly line can't meaningfully move the needle, so the pay-off to free-riding is likely to outweigh the pay-off to working harder that equity could provide. So you don't see a lot of equity for low-level jobs, other than in start-ups, which are borrowing against their future by paying in equity. For whatever reason, american workmanship used to be the standard of quality, but now it's a mark of shame that I seek to avoid when making a purchase because I know, for whatever reason, the american worker doesn't care about quality. Obviously there is no incentive for him to care, and that's especially true in unions where employees can't be fired. Serendipper Philosopher Posts: 2180 Joined: Sun Aug 13, 2017 7:30 pm ### Re: Question for those in charge of hiring employees promethean75 wrote:running a business is uncommon because business owners are a minority... not because running a business is an 'uncommon skill'. you can make just about anyone a business owner if you gave them a calculator and a note pad. nothing to it. and 'difficult to do well' is like a hasty generalization. what if bob can do easily what john struggles to do? how do we quantify 'difficult'? It might be a better technique of persuasion if we concede a few points in favor of the capitalists. Running a business is a gigantic pain in the ass! Although, admittedly, most of it is self-imposed. I had to be a jack of all trades just to do one trade. I had to juggle employees who may or may not show up on time, or at all. I had to predict the weather, repair tools, repair damaged property, console customers, learn accounting, insurance, legalities,,, I was human resources, sales, mechanic, accountant, etc all rolled into one, plus being a worker and it drove me crazy! I just wanted to be left alone and work without dealing with a bazillion variables zooming in random directions, but if I wanted the money, then I had to do it. Not everyone can do that kinda thing. It requires a drive and motivation to get ahead. My complaint isn't against the small business owner, but the ceos, managers and executives who don't do anything, except play golf and fly around in private jets, while exploiting those who do all the work to support their opulence. Serendipper Philosopher Posts: 2180 Joined: Sun Aug 13, 2017 7:30 pm ### Re: Question for those in charge of hiring employees promethean75 wrote: He is saying that the capitalists are providing jobs that wouldn't otherwise exist if not for the idea that one could get rich by providing those jobs. yeah there's a grey area here that's difficult to navigate. there are things that are necessary commodities, and then there are luxuries that aren't necessary... like the wacky wall walker. remember those? some dude got rich off that idea. however, why couldn't the state take the same risk and come up with some novel product like this for the same reason? I don't know. Who is the state? On what merit did they come to power? And does that merit convey creative genius? Doritos used to have more sprinkles. I emailed FritoLay and told them they're not putting enough flavoring on their chips, so they sent me coupons for free bags of bland chips. To date they still haven't fixed the problem and I hate the totalitarian control they have over a staple of Americana. But if the gov seized the company, would I have anymore influence than I do now? who knows... maybe the people would like to have a spatula that talks to you... let's try the idea and start making them. if we fail, we've lost nothing; we simply re-allocate the resources we use to produce the talking spatula to some other use. but what happens when a capitalist fails at such a venture? a small disaster for hundreds if not thousands of workers. That's a good point. anyway, don't think that people need to have the motivation of 'getting rich' to come up with marketable ideas. It's not to come up with the ideas, but to go to the effort of the pain in the ass of running the business. how many people with degrees end up working at mcdonalds because they can't find a job? The capitalist would say that no one forced anyone to get a degree, especially in something silly like philosophy. They would say it's a gamble that didn't pan out. in a socialist society, very special attention is paid to your skill set, and you WILL be put where you are most able to perform according to your skills. if you don't want to do this... then go get a job at mcdonalds. but at least you are given the option to decide, rather than having to take the job because you are not given the opportunity to do what you do best. an astrophysicist working at harris teeter is some bullshit that would only happen in capitalism. Makes sense. Serendipper Philosopher Posts: 2180 Joined: Sun Aug 13, 2017 7:30 pm ### Re: Question for those in charge of hiring employees So Stacey Lou (you invention) isn't bearing any risk, she's being paid a salary rather than whatever surplus the business earns, she isn't the driving factor for the business, she gets her direction from some other person. She isn't doing what the owner does. consumers who buy things value the things they buy, and couldn't care less what 'risk' is taken by a company or what the 'driving factor' is, or who gets what 'direction' from who. a consumer is not going to value the broom they just bought more because the owner of the company that made it stayed in the office and extra thirty hours and experienced five headaches. the capitalist across the street makes brooms too... and he stayed an extra forty hours and experience seven headaches. should the consumers who bought his broom value him more than the other capitalist across the street? no. they don't care anything about that shit. they care about brooms. we are talking about the TANGIBLE value prescribed to the market by those who participate in it by buying. what i'm saying is that the REAL value of any given form of labor is worth what it is, based on to what extent it is part of the production of things consumers buy. this means that when capitalist does x, it is no more 'valuable' than when stacey lou does it, because x has no tangible value other than what it contributes to production. what all this means (and this will address your comments too, dipper) is that we are either just talking about capitalism, or creating arguments that are being made to defend and justify it. and the above argument does no such thing. rather it's just something the capitalist tells himself after a careless and uncritical examination of what 'value' means. no special feature is given to the capitalist for all the headaches and struggles and risks and whatever else he has/takes when we are asking about the value of his actual labor... what he actually, physically does in the chain of production. and if any of those things can also be done by a worker, then those things are not special forms of labor that require a capitalist to be 'done'. so to say 'capitalism is necessary because there is a special kind of work that only an owner can do' is nonsense. and to further say that capitalism is good because it creates a context in which a class of people will exist to be able to do that special work, and be needed to do that special work, is an extension of the same nonsense. if we are merely describing capitalism, then yeah, these points being made in this thread are fine. but if these points are being raised as some kind of defense for capitalism, it ain't workin'. Every time anyone voluntarily exchanges dollars for goods or services, they believe they are getting more value in goods or services than they are giving up dollars. And simultaneously, every time anyone voluntarily exchanges goods or services for dollars, they believe are getting more value from the dollars than they are giving up in goods or services. That's what makes economic transactions happen: both parties believe they will be better off after the transaction. very true, but here's the difference. and it has to do with how 'profit' is defined here. of course, both the wage worker and the capitalist are content with their transaction insofar as each believes it will bring them into a state of greater satisfaction. but it's the nature of the satisfying thing that is different; a worker cannot buy anything with the happiness he just got from accepting the job... but a capitalist can buy something with the profit he makes from selling the worker's products. the worker's profit is the satisfaction he experiences... a mental and emotional abstraction. the capitalists profit is money... a real, concrete thing.... that, incidentally, can be used to purchase more forms of satisfaction. but a worker can't use a mental and emotional abstraction to purchase anything. different kind of profit. promethean75 Philosopher Posts: 3575 Joined: Thu Jan 31, 2019 7:10 pm ### Re: Question for those in charge of hiring employees Silhouette, I lean towards seeing morality as something that flows from reason, so I'm tempted to say that rational choices cannot be unethical. However, that invites a lot of post-hoc rationalizing about how anything that look immoral is really irrational on some other level. Another way to say what may amount to the same thing is that whenever the market creates outcomes that seem immoral in a utilitarian sense, it's a market failure, almost by definition. If market transactions are voluntary, the parties are going to be made better off or unaffected -- the choice is the evidence. Third-parties can be hurt by transactions, and that is one type of market failure. But I see the market as primarily about information: it aggregates and disseminates information about peoples wants and the ability to meet them, and that enables the production of significant value. As such, we can learn some things we might not like, for example that people don't actually value privacy, or that the market for porn is bottomless. In that sense, I take what you call the "pro-Capitalist" attitude: if our ethics are utilitarian, we're revealing our utility through the market, and we should hesitate to label the outcomes unethical in the absence of evidence that the information is being distorted. And, by the same token, we should hesitate to intentionally distort the information. That said, we know a lot about certain market failures, certain areas where the market doesn't accurately aggregate information, e.g. because the people affected don't get a say on the price, or because the individuals who do affect price are behaving in strictly irrational ways (i.e., their preferences aren't self-consistent). To me, the cooperative effort is structuring the market toward the end on minimizing those failures, and maximizing the information processing power of the market. I think this is not quite capitalism, though it often aligns with it. There's space for things like redistribution, which can improve information by pricing in the common good of a well structured market, and by shifting some buying power from low marginal utility spenders to high marginal utility spenders. Serendipper wrote:UBI should be the amount of money required to at least live a meager existence or else it wouldn't fulfill its purpose of making all work voluntary. I think making work more voluntary is good, but I don't think the minimum is survival; I would support a very low UBI. If we can afford that, and we can maintain productivity through automation, all the better, but that isn't a given. I think it should be about giving people a real dividend of the positive spillovers of a well-functioning economy, and pricing in the value of that cooperative effort. Serendipper wrote:Only the capitalists make that argument. I don't see many socialists hollering taxation is theft lol. It's only the pirates proclaiming pirated loot is proprietary. Well, your boy Daly was a tax protester. Socialism bleeds into anarchism at certain extremes. Given horseshoe theory, I would not be surprised to see a similar sentiment expressed by extreme socialists (though maybe you would not call them socialists). But in any case, I don't get the impression that most capitalists make that argument. Capitalism requires a certain amount of market regulation and enforcement of contracts and private property rights, it has to accept some mechanism for funding those things. Serendipper wrote:Yes it's unrealistic, but my point isn't to fix the system, but illustrate what's going on and how the rich are getting that way. And my point is that the question doesn't really do that. If it's unreasonable for both the company and the employee to ask for the equivalent information, it tells us more about what's reasonable for any party to a market transaction to expect, rather than about any inequalities in bargaining power between parties. Serendipper wrote:Management and executives are the ones overpaid to start with. They don't do anything commensurate with their pay which is a disservice to shareholders and society. Come now, you don't care about shareholders! But I mostly disagree. The value produced by management and executives is hard to quantify, but that cuts both ways. I would argue, and the market certainly indicates, that managers are valuable. However, it does seem likely that top executives are overpaid, ironically due in part to a discontinuity in information availability: the salaries of CEOs of publicly traded companies is public, which tends to drive up the price of CEOs! I strongly support making everyone's income public, though that would need to follow implementation of a better social safety net. promethean75 wrote:consumers who buy things value the things they buy, and couldn't care less what 'risk' is taken by a company or what the 'driving factor' is, or who gets what 'direction' from who. Sure, but the things they buy don't exist without someone taking the risk. If consumers want things to buy, they also want the people who take the risks to take the risks. They want someone to be the driving force on bringing a product to market, and someone to direct the whole operation to make it run. And so, because those activities result in the things that the consumers buy, the consumers do care, they just don't know that they care. There's a bit of survivorship bias in your argument here. Lost of companies go under, because consumers don't want what they offer. But what consumers want is an unknown until they are offered things to buy and either choose to buy them or not. You can't choose to only propose true hypotheses, you can't only run experiments that will vindicate your hypotheses, and you can't only create products that are exactly what consumers want. You need the failures to have the successes, and you need people to take the risk to provide both. promethean75 wrote:the worker's profit is the satisfaction he experiences... a mental and emotional abstraction. the capitalists profit is money... a real, concrete thing.... This is a weird argument. Workers are literally paid in money. EDIT: words User Control Panel > Board preference > Edit display options > Display signatures: No. Carleas Magister Ludi Posts: 6109 Joined: Wed Feb 02, 2005 8:10 pm Location: Washington DC, USA ### Re: Question for those in charge of hiring employees Ah but a wage/salary is not a 'profit', see. These are agreed upon amounts of money to be paid in exchange for a certain period of performed work or a certain unit of production. And this amount is always less than what the product is worth (what the capitalist gets for it).... so there is no profit being made here. If anything, it's negative profit. I'm in a burger king at the moment so im'a holla atcha later. promethean75 Philosopher Posts: 3575 Joined: Thu Jan 31, 2019 7:10 pm ### Re: Question for those in charge of hiring employees But the relevant 'product' here is the labor the worker is providing. And the wage is always greater than the value of the labor from the perspective of the worker. So the worker trades her labor for money, and the difference in value to the worker is the worker's profit. The employer trades money for labor, and the difference in value to the employer is the employer's profit. And both the employer and the worker profit because economic transactions are positive sum. User Control Panel > Board preference > Edit display options > Display signatures: No. Carleas Magister Ludi Posts: 6109 Joined: Wed Feb 02, 2005 8:10 pm Location: Washington DC, USA ### Re: Question for those in charge of hiring employees Carleas wrote:But the relevant 'product' here is the labor the worker is providing. And the wage is always greater than the value of the labor from the perspective of the worker. The value of the labor for the laborer, in that moment, perhaps gambling. I have crawled to the edge of the desert nearly. Yes, I take out my wallet and pay the demanded 1000 bucks for the bottle of water from the opportunist tourist I bump into just before going unconscious. Of course I make that decision and survive. But was the value to me in that situation the value of the bottle of water? Was the value of my labor - given I have a family, given the economic situation, given....etc. - the value it was to me given a situation - a situation perhaps encouraged by the firm I am working for - the actual value of my labor? The laborer is often making a gamble - certianly many miners were, for example - given situations that were shaped to a much greater degree by the people offering them a certain wage for their labor. Well, you showed up, so that means you are getting what you consider your labor is worth, plus something.... I don't think that holds. Did it hold for sharecropper southern blacks? The options by those in power to make a society with certain characteristics that then in turn allow for very limited choice which allows for wages at a level that is very low. At what point between sharecropper south and now and in what industries did fairness become the rule? Karpel Tunnel Philosopher Posts: 3405 Joined: Wed Jan 10, 2018 12:26 pm ### Re: Question for those in charge of hiring employees Carleas wrote:Silhouette, I lean towards seeing morality as something that flows from reason, so I'm tempted to say that rational choices cannot be unethical. However, that invites a lot of post-hoc rationalizing about how anything that look immoral is really irrational on some other level. The first sentence looks like modus ponens, but the distributivity looks like "I form", and the second sentence seems to be an admission of a propositional fallacy if you try to affirm the consequent. That is to say, if morality is something that flows from reason, does that mean that immorality cannot also flow from reason? Further, cannot morality flow from something other than reason: say irrationality? Or do you wish to deny the antecedent as well? This whole area of thought seems to be trespassing on the realm of the Naturalistic fallacy, or the Is-ought problem. However I am inclined to think of certain rational decisions as resulting in something that looks like morality close enough to be taken for it e.g. giving to others because you reason that it will create a better atmosphere, even beyond the direct relationship between giver and givee. Haha, I like that term, "givee": "taker" seems too tainted by its possible usage as someone who is taking advantage of another's kindness in a competetive context rather than as part of the event of giving in the cooperative sense. But I also think morality can come irrationally, and that immorality can be both rational or irrational. Carleas wrote:Another way to say what may amount to the same thing is that whenever the market creates outcomes that seem immoral in a utilitarian sense, it's a market failure, almost by definition. If market transactions are voluntary, the parties are going to be made better off or unaffected -- the choice is the evidence. Third-parties can be hurt by transactions, and that is one type of market failure. So if it were accepted that the market creates outcomes that seem immoral in a utilitarian sense, necessarily, then it is by definition a failure. Not a complete failure though, since not all outcomes are immoral, but when it functions as it does without equity of opportunity, that is immoral. Carleas wrote:But I see the market as primarily about information: it aggregates and disseminates information about peoples wants and the ability to meet them, and that enables the production of significant value. As such, we can learn some things we might not like, for example that people don't actually value privacy, or that the market for porn is bottomless. In that sense, I take what you call the "pro-Capitalist" attitude: if our ethics are utilitarian, we're revealing our utility through the market, and we should hesitate to label the outcomes unethical in the absence of evidence that the information is being distorted. And, by the same token, we should hesitate to intentionally distort the information. I agree that the nuanced information that the market provides is a huge strength. And if nothing else, its results do open up social questions that may not have otherwise been given credence, such as your examples of whether people really do value privacy and to what extent they do porn. This is most certainly progress and I would not hesitate to give the market its due for all the good that it does, but it is without ungratefulness that I still ask whether or not we can do better. Computational power, particularly enhanced by AI is an unprecedented injection that is lacking in previous experiments to do without it, and it cannot be overlooked. However I do think we have evidence that the information that the market provides is being distorted. One way is what I'm intending my argument to convey: that voluntary transactions compromise the degree of consent between the two transacting parties - in favour of the one with more power. If we really wanted to know how much something is mutually worth, both of those transacting must have the same to lose and the same to gain prior to the transaction. As it is, we only learn what it's worth within the context of prior inequality. There's an overall correlation between the two, which is why the market is not useless and still serves a useful purpose and provides information that is not without validity. Carleas wrote:That said, we know a lot about certain market failures, certain areas where the market doesn't accurately aggregate information, e.g. because the people affected don't get a say on the price, or because the individuals who do affect price are behaving in strictly irrational ways (i.e., their preferences aren't self-consistent). In large part the market requires complete rationality in order to function optimally in the ethical sense, however it also permits the practice of advertising that operates almost purely to encourage irrationality. So we have at base a system that results in lack of equity of opportunity, in favour of those with more opportunity and against those with less, causing growing inequality, only enhanced by the effects of the advertising industry that it allows. Growing inequality in favour of the powerful tends towards monarchy whether or not it can finally reach it - and I wouldn't be so quick to say it can't. So not only does the market result in doing away with itself, it tends towards the centralisation of power. Is that ethical? Carleas wrote:To me, the cooperative effort is structuring the market toward the end on minimizing those failures, and maximizing the information processing power of the market. I think this is not quite capitalism, though it often aligns with it. There's space for things like redistribution, which can improve information by pricing in the common good of a well structured market, and by shifting some buying power from low marginal utility spenders to high marginal utility spenders. Yes, it's possible to cooperatively minimise the failures of the market alongside Capitalism - but not aligned with it: the opposite in fact. Redistribution directly counters Capitalism and we can improve information and shift buying power from low marginal utility spenders to high, but with the tide against us. Just think how many industries exist whose sole purpose is to allow Capitalism to continue, that nobody would miss if they were removed from the world excepting of their value that exists only because of Capitalism. I am talking not only about advertising, but the financial services, so much admin - all the red tape that is passed off as a result of the enemy of Capitalism, when in fact it would not be necessary if not for Capitalism in the first place. Who is a high marginal utility spender? Someone like Elon Musk (used to be?) or Bill Gates before him when he was helping create the world's most popular operating system rather than simply renting it like he does now - these are figureheads of bringing technologies that empowered humanity in a very real sense. There have been countless more with less attention afforded to them who have contributed to such successes as these - these are the people that we want to be working. Does the world really need another recruitment agency to drive it into the future, or do these people only have jobs in order to maintain the necessary foundation for voluntary trade: that everyone has a job and can thus warrant money being paid to them? These people are employed to dig holes and fill them back up compared to the real innovators of the world - get rid of them. The free market it becoming more of a crutch than a liberation. Silhouette Philosopher Posts: 4392 Joined: Tue May 20, 2003 1:27 am Location: Existence ### Re: Question for those in charge of hiring employees Carleas wrote: Serendipper wrote:Only the capitalists make that argument. I don't see many socialists hollering taxation is theft lol. It's only the pirates proclaiming pirated loot is proprietary. Well, you're boy Daly was a tax protester. Socialism bleeds into anarchism at certain extremes. Given horseshoe theory, I would not be surprised to see a similar sentiment expressed by extreme socialists (though maybe you would not call them socialists). But in any case, I don't get the impression that most capitalists make that argument. Capitalism requires a certain amount of market regulation and enforcement of contracts and private property rights, it has to accept some mechanism for funding those things. I don't know if most people who describe themselves as capitalists make that argument, but if the argument is made, it could only be by a capitalist lest a socialist undermine his own social aspirations. Anarchical communism is not a teleological goal per se, but an inevitable outcome of technological progression transitioning from feudalism to capitalism to socialism and finally the government falls away like rotary phones and communism has arrived once scarcity has been eliminated. So still, no "taxation is theft" argument need be advanced by a socialist having ungoverned communism as the ultimate goal since money will have been antiquated once scarcity is gone. Serendipper wrote:Yes it's unrealistic, but my point isn't to fix the system, but illustrate what's going on and how the rich are getting that way. And my point is that the question doesn't really do that. Yes it does. It illustrates how the employee did not agree to the division of the productivity, so the exchange was not voluntary, and involuntary exchanges are theft. So therefore, the taxation of that theft is simply stealing back what was stolen. If it's unreasonable for both the company and the employee to ask for the equivalent information, it tells us more about what's reasonable for any party to a market transaction to expect, rather than about any inequalities in bargaining power between parties. That doesn't refute anything I said. Sure, ask me how much I need to live, but it's irrelevant to the discussion about the division of the productivity. How the pie is sliced is not contingent upon how much I need to survive. How the pie is sliced is dependent upon how each party sees what is fair. Offer me a job and tell me what my service is expected to net, then we'll hash out and agree to a fair split of the profits. At that point, taxation could be considered theft since "who gets what" was agreed to and nothing was stolen. Serendipper wrote:Management and executives are the ones overpaid to start with. They don't do anything commensurate with their pay which is a disservice to shareholders and society. Come now, you don't care about shareholders! I care more about shareholders than ceos. But I mostly disagree. The value produced by management and executives is hard to quantify, but that cuts both ways. I would argue, and the market certainly indicates, that managers are valuable. If the market really determined the value of managers, then a job would not come with a specific salary, but instead would take bids. When you want to put a roof on your house, do you announce that you will pay10,000 for a roof and then interview for the job? No. You call a bunch of roofers and take bids. So if someone wanted to hire a manager in the spirit of the free market, then they would take bids from applicants and probably take the lowest offer. That would be a free market.
It's like my local walmart paying $250k for a store manager. I bet I could find someone to do the job, almost certainly better since he's an idiot, for half as much. In the case of ceos, why pay some drooling moron like John Stumpf$20 million to NOT be aware his bank is ripping people off? I could find someone to be just as inept for $100k. However, it does seem likely that top executives are overpaid, ironically due in part to a discontinuity in information availability: the salaries of CEOs of publicly traded companies is public, which tends to drive up the price of CEOs! I strongly support making everyone's income public, though that would need to follow implementation of a better social safety net. I don't see how publicity changes anything. "Hello, I saw publicly that you're paying your ceo$20 million. Well, I can save your company $19 million right now: hire me and I'll do the job for$1 million." The reply would be, "I'm sorry sir, but we like giving shareholder money away and we're only interested in saving money if it comes at the expense of a grunt." I'll retort, "Ok fine, I'll do the job for $300 million; is that better?" They'll quip, "Well, you realize you'll be expected to do certain favors... wink wink... and your nose doesn't seem to have enough brown on it to be worth$300 million."
Serendipper
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### Re: Question for those in charge of hiring employees
carleas wrote:Sure, but the things they buy don't exist without someone taking the risk. If consumers want things to buy, they also want the people who take the risks to take the risks. They want someone to be the driving force on bringing a product to market, and someone to direct the whole operation to make it run. And so, because those activities result in the things that the consumers buy, the consumers do care, they just don't know that they care.
okay sure, but this point isn't something that's gonna prove the necessity of capitalism, because those same risks would be taken in a socialist society. that's all i've been saying. all this praise for the capitalist is hollow and transparent.
carleas wrote:But the relevant 'product' here is the labor the worker is providing. And the wage is always greater than the value of the labor from the perspective of the worker. So the worker trades her labor for money, and the difference in value to the worker is the worker's profit. The employer trades money for labor, and the difference in value to the employer is the employer's profit. And both the employer and the worker profit because economic transactions are positive sum.
but the wage isn't greater than the value of the labor, because the value of the labor is equal to the price of the product/service when it is sold. that's the real, tangible value. and arguments like 'well the worker took the job because he must have valued his minimum wage' means only 'he'd rather take minimum wage than be jobless and living under a bush somewhere'.
the system forces workers into a corner, then argues that the system must be reasonable because the worker took the job... because he willingly accepted the minimum wage. but what other choice did he have? he picked the lesser of two evils, that's all.
in any case, i've never known a worker who thought 'his wage was greater than the value of his labor'. that's ridiculous. i've been a wage worker for over twenty years, and anything i've ever produced was sold for at least three times what i was paid to make it. and that's at best. i wrapped an exposed ceiling truss with poplar trim a month ago that my boss bid at $2,000. it took me all of two hours. i made$40 dollars, he made $1,960... and didn't do a damn thing but get in my way. even deducting his overhead from that profit - cost of tools, insurance, materials, etc. - he still made a grand. now i'm not complaining, but that's disgusting. i'm not going to call it immoral or unfair or any bullshit like that. i'm gonna simply call it ugly, and i'm gonna ask myself why workers still continue to allow this nonsense to happen. promethean75 Philosopher Posts: 3575 Joined: Thu Jan 31, 2019 7:10 pm ### Re: Question for those in charge of hiring employees " because the value of the labor is equal to the price of the product/service when it is sold." But then you have to count the labour of the people that transport it, that design the logistics, that coordinate the different stages, all the way up to the businessmen that get the whole thing cracking. N'est-ce pas? Pedro I Rengel ILP Legend Posts: 6697 Joined: Mon Feb 05, 2018 2:55 pm ### Re: Question for those in charge of hiring employees I no speaka spanish, but that's right. All those things are part of the chain of production, and all those people are being paid a wage/salary that will be less than the value of the fraction of labor they provided in that chain. Now who's the guy that isn't being paid a wage? Where does he get his money if he isn't being paid? He skims the surplus value off the top, and 'skimming' is not a form of labor. promethean75 Philosopher Posts: 3575 Joined: Thu Jan 31, 2019 7:10 pm ### Re: Question for those in charge of hiring employees Well a lot of people get paid by commission, some truck drivers for instance. I find the name you give to the pay they get is more or less irrelevant, it is the amount the person is able to get for that labour. You say skimming. Again, I find what you call it pretty much unimportant. The question is, why does that person get to "skim?" Also, by what you just said before, it is not "surpluss value," as it is contemplated in the final price of the product and/or service. Pedro I Rengel ILP Legend Posts: 6697 Joined: Mon Feb 05, 2018 2:55 pm ### Re: Question for those in charge of hiring employees Karpel Tunnel wrote:But was the value to me in that situation the value of the bottle of water? Was the value of my labor [...] the actual value of my labor? and also promethean75 wrote:the value of the labor is equal to the price of the product/service when it is sold. that's the real, tangible value. I don't see the distinction between "value to me" and "actual value" (or "real, tangible value"). In the water bottle example, it seems like maybe you're looking for an average value over time, i.e. I'm willing to pay$1000 for it after crawling out of the desert, but only $1.95 when choosing between bottled and tap. And I think there's a couple ways to look at this. In one version, your decision to pay$1000 is strictly irrational. Say we replace the water with food, and you're on the brink of starvation from your time in the desert, and you are offered nutritious but bland gruel for $1, and equally nutritious but very flavorful steak for$1000. If you choose the steak, that's probably irrational, because if you take the gruel you will survive and you can buy a steak for $12 later. Taking the steak is irrational in the sense that it isn't consistent with all of your preferences, and you choose it because you're blinded by hunger and not thinking clearly. On the other hand, if the steak is the only option, and you die if you don't take it, then$1000 is a steal, you'll gladly pay $1000 to avoid death, and that choice is consistent with all your preferences and not a product of hunger-blindness. In the first case, we should say that the value of the steak isn't$1000, and in the second it is (or rather, that the steak is more valuable to you than $1000). The fact that in different circumstances you would choose differently doesn't mean that the exchange isn't a real reflection of the actual value. "The" actual value is always just a value to a specific person in a specific situation. And all any transaction tells us is that one party values one thing more than the other, and the other party feels the other way. So, you might actually have been willing to pay$10k, or $1m for the steak, and the person selling it to you might have been willing to accept$12.
So too with an exchange for labor. The only reason the employer is willing to trade money for labor is because she values the labor more. The only reason the worker is willing to trade labor for money is because he values the money more. The actual spread between what the employer would be willing to pay and what the worker would be willing to accept is unknown. But it is known that the employer and the worker disagree about the value of the money and the labor, and that disagreement is what makes the transaction possible. If they both agreed, or if they were prohibited from accepting an exchange at anything but the maximum price the employer would be willing to pay (which is what it seems Promethean is suggesting), the transaction just wouldn't happen.
Karpel Tunnel wrote:Did it hold for sharecropper southern blacks?
Yes, given the constraints that were placed upon them. There were legal restrictions on where they could work, both on them and on employers, which suppressed demand on their labor. Cultural taboos and prejudices also restricted their options, but the legal and quasi-legal restrictions were the more pernicious (by quasi-legal, I mean enforcement of the status quo by groups like the KKK, which were not technically the law but operated with its tacit protection and blessing). Without these, the price of black labor would have been artificially low, and enterprising business owners could take advantage of the suppressed wages, which would work to counteract the prejudice and raise black wages over time (and simultaneously suppress wages of white laborers towards an equilibrium).
That appears to be what was happening, as evidenced by the introduction of minimum wage laws that were expressly advocated as a way to price out black laborers: because racism artificially reduced the value of black labor, requiring that the minimum amount that could be paid be above that value would eliminate competition. But if racism wasn't creating opportunities for non-racist employers to get comparable labor at below-market rates, such a cartel wouldn't have been appealing to the racist majority.
Silhouette wrote:This whole area of thought seems to be trespassing on the realm of the Naturalistic fallacy, or the Is-ought problem.
I'm not sure how to think of morality in the context of the market. A market economy takes values as inputs, so it seems like the concept of trying to decide our values about such a system generates the messy problems of recursion. What oughts can be offered about a system that takes oughts as inputs and generates is's as outputs? That is not entirely rhetorical, but it is not something I have an answer for.
Suffice it to say that the market is as morally pluralist as its participants, that most of the outcomes are a-moral, and that rationality for the purpose of economic analysis is scoped to preference self-consistency.
Silhouette wrote:If we really wanted to know how much something is mutually worth, both of those transacting must have the same to lose and the same to gain prior to the transaction.
While I agree with the general point that a certain amount of redistribution can improve the information the market generates, I don't think it's true that participants needs to be equals in order to generate a 'real' value. As I argue above to Karpel and Promethean, there is no such value independent of the participants, and economic exchanges require that the participants value the things exchanged differently. Decreasing inequality will decrease the spread between people, but only up to a point, so there are diminishing returns in terms of information. And redistribution is itself distorting, so significant redistribution to drastically reduce inequality will at some margin eliminate more information than it produces.
Silhouette wrote:In large part the market requires complete rationality in order to function optimally in the ethical sense, however it also permits the practice of advertising that operates almost purely to encourage irrationality.
There's a lot of wiggle room in "almost purely", but to offer a small defense of advertising as a rational and pro-social enterprise: advertising reduces search costs, which benefits consumers by making it easier to find the goods they want to buy. The internet has obviated this a bit by decreasing search costs across the board, but advertising is still a reliable signal of legitimacy, it strengthens brands, which in turn incentivize quality. Where it's intentionally deceptive, it's bad, and you're right that it can encourage irrationality even when it isn't lying. But it is not without benefit for rational consumers.
Silhouette wrote:[N]ot only does the market result in doing away with itself, it tends towards the centralisation of power.
I kind of agree with this, and in fact so do many of the most free market people I read. Libertarianism takes for granted that governments will be captured for the benefit of the rich, and proposes the solution of sharply limiting government powers, such that any action that exceeds the limit is immediately recognized as illegitimate. That prevents the rich from buying too much influence by capping the value of that influence.
The problem is that government needs to be the most powerful enterprise, it needs to be more powerful than every company it oversees, or else the rich can succeed in capturing society by capturing the largest companies. But if government is more powerful than every company, then it will always be worth capturing.
But I don't see the alternatives doing much better here. Centralizing power away from the free market just seems to expedite the process. And other solutions seem to depend on the idea that people just magically won't do that anymore. I think there is no solution, it's a balance that must continue to be fought for.
Silhouette wrote:Who is a high marginal utility spender? Someone like Elon Musk (used to be?) or Bill Gates before him when he was helping create the world's most popular operating system rather than simply renting it like he does now - these are figureheads of bringing technologies that empowered humanity in a very real sense.
This is an interesting suggestion, not at all what I had in mind but I can see the line of thinking and I think there's some merit to it. When I think of high marginal utility spenders, I'm thinking of the people struggling to make rent or feed their families. An extra dollar to those people is very, very valuable. An extra dollar to Musk or Gates seems wasted, given how many dollars they're sitting on. By moving excess dollars that lay idle with the rich (or that the rich use for another car or another vacation or another molecular gastronomy meal) to the poor who will immediately put it to use in ways that will measurably improve their lives, we can increase the effective value in the economy, and get better information about what things are worth.
But it's true that some desperately poor people will put the money into drugs or gambling, and Musk has at times leveraged himself to the hilt to create multiple enterprises that have immense social good. Still, I think that's the exception. Most successful people, even when they generally use money wisely, are also comfortable and consume wasteful luxuries. And most poor people, even when they generally make financial mistakes, will use more money in socially positive ways. On average, I would expect the marginal dollar to be more valuable in the hands of the poor than in the hands of the very rich.
Serendipper wrote:I don't know if most people who describe themselves as capitalists make that argument, but if the argument is made, it could only be by a capitalist lest a socialist undermine his own social aspirations.
...
At that point, taxation could be considered theft since "who gets what" was agreed to and nothing was stolen.
See, this is why I think socialists are not as far from "taxation is theft" as you suggest. I would argue, and I think it's consistent with capitalism (even required by pragmatic capitalism) that even when the split of the profits between two parties is absolutely fair, there's perfect information and no asymmetry of bargaining power, taxation is still not theft, because the transaction is only possible in a world in which tax-funded institutions support market transactions.
Taxation isn't punishment, and shouldn't be thought of that way. As I pointed out to Silhouette above, we shouldn't be blaming the lucky for making rational choices in the context of their luck. It should be used to price in the cost of market-supporting institutions and to price in harmful externalities (as with carbon and sin taxes), and more generally to raise the funds necessary to fund the commons and stabilize society. That's not theft, it's the cost of doing business, and it's justified even when the business is as fair as it can be.
Serendipper wrote:It illustrates how the employee did not agree to the division of the productivity, so the exchange was not voluntary, and involuntary exchanges are theft. So therefore, the taxation of that theft is simply stealing back what was stolen.
But both sides of the exchange lack that information. The exchange is labor for money. The employee doesn't know the complete picture of how that labor will be used to generate profit for the employer, and the employer doesn't know the complete picture of that money will be used to satisfy the employee's preferences. Both parties to the transaction lack information. Moreover, they both know they lack information, and they voluntarily engage despite that lack of information. Perfect information isn't necessary for a transaction to be voluntary.
Let me propose a similar situation that may get on what we actually disagree about. Consider two firms negotiating. One firm is buying services from the other firm. The buyer will use the services to turn a profit, the seller is turning a profit on the sale. They both know this, and they're both OK with it. They don't need to open the books to each other to make that exchange fair.
To me, this exchange is comparable to the employer-employee exchange. It does not seem so for you.
Serendipper wrote:If the market really determined the value of managers, then a job would not come with a specific salary, but instead would take bids.
By this argument, the market doesn't determine the price of consumer goods, since they come with a specific price tag and 7-Eleven doesn't take bids for soda.
Serendipper wrote:I don't see how publicity changes anything. "Hello, I saw publicly that you're paying your ceo $20 million. Well, I can save your company$19 million right now: hire me and I'll do the job for $1 million." The reply would be, "I'm sorry sir, but we like giving shareholder money away and we're only interested in saving money if it comes at the expense of a grunt." I'll retort, "Ok fine, I'll do the job for$300 million; is that better?" They'll quip, "Well, you realize you'll be expected to do certain favors... wink wink... and your nose doesn't seem to have enough brown on it to be worth $300 million." This seems to rely on the premise that CEOs don't do anything, it's not difficult, and/or the skillset is not rare, and anyone can be dropped in and do a good job. That isn't obviously the case, CEOs have a lot of power and a lot of trust, the talent pool is small and competition is fierce. Publicity puts the employer at an informational disadvantage. If CEO salaries weren't public, hiring a new CEO at a drastic pay cut would be easier. Consider how business often (illegally) forbid employees from discussing their salary with each other. That helps keep wages down, because it lets business price discriminate in buying labor (paying worse employees less), and employees are less motivated to ask for more money because they don't know they're being hosed and no one else sees how little they make so they don't lose face. CEOs know what their peers are making, so they know what a fair package looks like, and they're motivated to bargain for more because they and everyone can see how they're valued relative to their peers. promethean75 wrote:okay sure, but this point isn't something that's gonna prove the necessity of capitalism I agree. But to the extent that the argument against capitalism depends on the premise that managers don't do anything, acknowledging that managers add something of value does weaken that argument and so supports capitalism. User Control Panel > Board preference > Edit display options > Display signatures: No. Carleas Magister Ludi Posts: 6109 Joined: Wed Feb 02, 2005 8:10 pm Location: Washington DC, USA ### Re: Question for those in charge of hiring employees Carleas wrote:I don't see the distinction between "value to me" and "actual value" (or "real, tangible value"). In the water bottle example, it seems like maybe you're looking for an average value over time, i.e. I'm willing to pay$1000 for it after crawling out of the desert, but only $1.95 when choosing between bottled and tap. I'm saying that the bottle of water only has the value it was sold to me at because the person who sold it to me is a vicious person combined with the scenario. And I think there's a couple ways to look at this. In one version, your decision to pay$1000 is strictly irrational.
No, I'm about to lose consciousness having gone without water long enough to be in danger. The only person who knows I am on this side of the sand dune is a horrible person who sees me as an opportunity to make money. He may not tell anyone I am there so I die. It is rational to buy his water, my money being valueless if I am dead.
On the other hand, if the steak is the only option, and you die if you don't take it, then $1000 is a steal, you'll gladly pay$1000 to avoid death, and that choice is consistent with all your preferences and not a product of hunger-blindness.
In the first case, we should say that the value of the steak isn't $1000, and in the second it is (or rather, that the steak is more valuable to you than$1000).
As a social mammal I find this idea that the steak has that value bizarre.
Karpel Tunnel wrote:Did it hold for sharecropper southern blacks?
Yes, given the constraints that were placed upon them. There were legal restrictions on where they could work, both on them and on employers, which suppressed demand on their labor. Cultural taboos and prejudices also restricted their options, but the legal and quasi-legal restrictions were the more pernicious (by quasi-legal, I mean enforcement of the status quo by groups like the KKK, which were not technically the law but operated with its tacit protection and blessing). Without these, the price of black labor would have been artificially low, and enterprising business owners could take advantage of the suppressed wages, which would work to counteract the prejudice and raise black wages over time (and simultaneously suppress wages of white laborers towards an equilibrium).
It seems to me the context of the discussion with Serendipper is if there is exploitation. If the people setting the market value have contributed to a value they would never have put on the product or labor themselves - if they wanted to buy the product or if they were doing the labor - they are being immoral.
I really do understnad that if money changes hands then people made a choice. It seems to me this is oddly leaving out the core of Serendipper's context which is a moral one.
Karpel Tunnel
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But how much of this is just framing? Take the question in a more abstract form: I have an item that you want to buy, and we know that you will get >$1000 worth of value from that item. What's a fair price to ask of you for that item? Framed this way, it's much less morally repulsive, and it's very similar to Serendipper's question. But it's the same question, we're really supposing as part of the hypothetical that the bottle of water is worth >$1000 to you. So, two people value a good differently, and we're trying to find a fair price so that the two people split the surplus. If you're really going to die, you likely value the water bottle at much greater that $1000. This reframing is not dishonest, it's only a difference of emphasis. I agree that intuitive morality says we should just give the dying person water, but we might reframe intuitive morality as naive morality. For example, take price gauging in the run-up to a hurricanes. People have strong intuitions against it, but price gauging in those situations serves a very important function that has positive social spill over. First, it maximizes the supply that will be available in the affected area, by compensating people for the risk and expense of making more supply available. Second, it limits hoarding: without price gauging, cases of water sell out in a few hours, but if they have to pay a price that accurately reflects the value they expect from the water, they will be more careful to buy only what they need and leave more for other people to buy. Price gauging looks opportunistic, but letting prices track value aggregates information and allocates scarce resources efficiently. That's what the market's for. That's a bit different from a one-off, dying in the desert situation, but it does demonstrate that economic exchanges that are intuitively icky can be socially beneficial. Sometimes our gut reaction is wrong. User Control Panel > Board preference > Edit display options > Display signatures: No. Carleas Magister Ludi Posts: 6109 Joined: Wed Feb 02, 2005 8:10 pm Location: Washington DC, USA ### Re: Question for those in charge of hiring employees For example, take price gauging in the run-up to a hurricanes. People have strong intuitions against it, but price gauging in those situations serves a very important function that has positive social spill over. First, it maximizes the supply that will be available in the affected area, by compensating people for the risk and expense of making more supply available. Second, it limits hoarding: without price gauging, cases of water sell out in a few hours, but if they have to pay a price that accurately reflects the value they expect from the water, they will be more careful to buy only what they need and leave more for other people to buy. Price gauging looks opportunistic, but letting prices track value aggregates information and allocates scarce resources efficiently. That's what the market's for. What about the people who can't afford to buy the water at inflated prices? They die. Their families die. They depend on the kindness of the "naive". Why are there slums in the richest country in the world? Important functions being served. Positive social spill over. Efficiency. phyllo ILP Legend Posts: 12115 Joined: Thu Dec 16, 2010 1:41 am ### Re: Question for those in charge of hiring employees phyllo wrote:Why are there slums in the richest country in the world? There are no rich countries. There are rich people. Your question should be "why are there slums in the country with the richest people in the world?" Then the answer becomes clearer. Pedro I Rengel ILP Legend Posts: 6697 Joined: Mon Feb 05, 2018 2:55 pm ### Re: Question for those in charge of hiring employees pedrosophocles wrote:The question is, why does that person get to "skim?" because it is allowed by law. the dual history of the gradual development of the politics and economics of western civilization involves a hidden pretense that's really quite brilliant. the idea that 'government' and the 'state' fundamentally restricts the freedom of people was a philosophical rumor set in motion by the bourgeois. it's purpose was to persuade the working classes to be suspicious of the 'state'... which would result in preventing the state from interfering with the acquisition of property and wealth through exploitation. the biggest enemy of the capitalist is not the 'worker', but the organized mass of workers - the 'state' - which would have the power to radically change and reform property laws. so basically, it's not that the 'state' is some evil, authoritarian entity that wants to restrict the rights and freedoms of the people. it's that only the state would have the power to control the laws that allow the capitalists their privilege to 'skim'. carleas wrote:I don't see the distinction between "value to me" and "actual value" i wasn't disputing that, and we haven't been on the same page for a week. this is why i don't do debates anymore. this discussion has been slowly twisting and turning... so much now that the original argument has been lost. i'm saying: a) the capitalist does not add anything to the chain of production that wouldn't be there if he did not exist. b) the capitalist's 'opinion' that what he does is valuable because he decides it is valuable, is irrelevant. c) the worker's value is equal to the value of what he produces. the value of what he produces is determined by the market. the wage that the worker gets in exchange for his labor is always less than the value of what he produces. the difference is the surplus value the capitalist gains through becoming an unnecessary and extraneous intermediary between the producer and the consumer. d) ergonomically, functionally, the capitalist is quite literally analogous to a parasite. but before you reply, i surrender. i can't muster enough interest in this discussion anymore to put the necessary effort into it. that, and i've been busy. promethean75 Philosopher Posts: 3575 Joined: Thu Jan 31, 2019 7:10 pm ### Re: Question for those in charge of hiring employees "because it is allowed by law." Allowed by is not a reason for a thing. It is, at best, a reason the thing is not stopped. You can do better than this. What is this shit? Pedro I Rengel ILP Legend Posts: 6697 Joined: Mon Feb 05, 2018 2:55 pm ### Re: Question for those in charge of hiring employees a) the capitalist does not add anything to the chain of production that wouldn't be there if he did not exist. Except, of course, the whole chain of production. Which he started. Minor detail. For behold, all acts of love and pleasure are my rituals Jakob ILP Legend Posts: 7193 Joined: Sun Sep 03, 2006 9:23 pm Location: look at my suit ### Re: Question for those in charge of hiring employees no, he slipped in there... what was already up and running. human beings have been organized producers since they developed opposable thumbs and dropped down from the trees. we've been designing and using technologies for eons, long before the 'capitalist' was even conceived of by some ruling class philosopher yesman. the only thing the capitalist ever 'got going' was wage labor when he evolved from the merchant into the employer and began paying workers to make things. then, as he accumulates wealth, he buys further means of production (factories, tools, etc.), he appropriates what was already in existence and made by workers. he doesn't start any chain of production. he slips into the mix after it's already going. minor detail. promethean75 Philosopher Posts: 3575 Joined: Thu Jan 31, 2019 7:10 pm ### Re: Question for those in charge of hiring employees phyllo wrote:What about the people who can't afford to buy the water at inflated prices? The same thing that happens to everyone who arrives at the store after the shelves are bare. The difference is that prices that track supply and demand minimize the number of people who don't get water. I agree that there is something unseemly in deciding who lives and who dies based on wealth. But I don't think it's better that more people die so long as the decision is made based on how early they got to the store instead of on wealth (especially because I expect 'how early they get to the store' to correlate with wealth anyway). Promethean, thank you, I understand if you're busy or over this conversation, please feel free to ignore what follows; I won't take your silence as disrespect or as a concession on any open points. But my replies are as much for me as they are for you, so I will think through your parting thoughts below. I've appreciated our discussion. promethean75 wrote:a) the capitalist does not add anything to the chain of production that wouldn't be there if he did not exist. I thought you had conceded this point here. In short, my contention is that the capitalist contributes risk-taking, initiating action, and organizing the enterprise. Also, Pedro made a good point in response to this claim that I missed: Pedro I Rengel wrote:Also, by what you just said before, it is not "surpluss value," as it is contemplated in the final price of the product and/or service. The point Pedro makes, as I understand it, is that the cost of the final good includes whatever amount the capitalist takes for herself. If that's the case, and if the capitalist adds nothing of value, then a competing good could be produced for less by paying the capitalist less, with the market price settling around the equilibrium of paying the capitalist zero or near-zero. The fact that this doesn't happen seems like strong prima facie evidence that the capitalist does indeed add value. promethean75 wrote:c) the worker's value is equal to the value of what he produces. the value of what he produces is determined by the market. the wage that the worker gets in exchange for his labor is always less than the value of what he produces. the difference is the surplus value the capitalist gains through becoming an unnecessary and extraneous intermediary between the producer and the consumer. This is the crux of the disagreement, but I think we can connect our positions. Take a laborer who makes widgets, which sell for$100 each. Each widget is made by assembling several components using some power tools.
Separate from (a) and separate from the value-to-who arguments I've been making, let's see if we can specify the price of 'what [the worker] produces' Call it P(w). It can't be equal to the price of the widget, because the widget is composed of raw materials that cost money. We'd also need to subtract the pro-rata price of the tools and their maintenance, and the power to run them. So, $$P(w) \leq 100 - (materials) - (overhead)$$
I would also subtract the price of coordination (i.e. ordering the materials, paying the electric bill). And I would add in the cost of fronting the money for the raw materials. I think both of these fall under your objection in (a), and I would respond that these are valuable.
So, I contend that
$$P(w) \leq 100 - (materials) - (overhead) - (coordination) - (risk)$$
and I think you contend that some of those values are just \$0.
If that's right, then we only disagree on 1) whether there are zeros in the equation, and 2) whether the employer has an obligation to pay the maximum amount that it would be willing to spend to obtain the inputs into the widgets (including P(w)). I think the answer to both is no.
User Control Panel > Board preference > Edit display options > Display signatures: No.
Carleas
Magister Ludi
Posts: 6109
Joined: Wed Feb 02, 2005 8:10 pm
Location: Washington DC, USA
### Re: Question for those in charge of hiring employees
There's the inherent problem of monopolies.
They make your discussions on capitalism, all of them, mere mental masturbation, and even more useless than that.
Ecmandu
ILP Legend
Posts: 11031
Joined: Thu Dec 11, 2014 1:22 am
PreviousNext | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.33479002118110657, "perplexity": 1779.7053128783552}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-50/segments/1606141183514.25/warc/CC-MAIN-20201125154647-20201125184647-00309.warc.gz"} |
http://stackoverflow.com/questions/2561702/how-to-fit-the-paper-size-to-the-content-in-latex | # How to fit the paper-size to the content in LaTeX
I'd like to create a pdf/ps/eps that contains only one single formula. I thought the easiest way would be to use latex. Unfortunately, I found no option to specify, that the paper-size should automatically be set to fit the contents.
I found that dvipng has a "-T tight" option, that actually does the trick, but... I want it in vector-graphics format.
Any suggestions?
Thanks.
-
With the standalone class, you get exactly what you want.
\documentclass{standalone}
\begin{document}
$x + y = z$
\end{document}
-
IMNSHO, this is the best answer; it's pure LaTeX, it doesn't rely on cranky external programs, and it's modern and up-to-date, and can be used with modern TeX processors like pdfLaTeX, XeLaTeX, and LuaLaTeX. I have no idea why some "challenged person" downvoted you, and I apologise on his behalf for the whole thinking TeX community. +1 – Brent.Longborough Jun 23 '13 at 10:13
Try pdfcrop, it crops your pdf to the minimum. You need to have Perl installed.
-
for Mac, there is a little app called LaTeXit which does exactly that. http://chachatelier.fr/programmation/latexit_en.php
-
Fixing the bounding box of generated EPS should help:
epstopdf --gsopt=-dEPSCrop blah.eps
or eps2pdf has a -B option that detects the tightest possible Bounding Box.
- | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9223862886428833, "perplexity": 3988.7319002266872}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-23/segments/1404776439014.63/warc/CC-MAIN-20140707234039-00041-ip-10-180-212-248.ec2.internal.warc.gz"} |
http://www.johnstowers.co.nz/blog/2007/12/11/jhbuild-adventures-on-windows/ | #### Dec 11, 2007
Background: I'm going home to my parents house for Christmas, and because I don't have a laptop, I thought it would be the perfect opportunity to use their computer to get Conduit working on windows. However I could not find windows builds of (py)goocanvas anywhere. Never minding a challenge I thought it would be a good experiment to see if I could build pygoocanvas for windows via cross-compilation or natively - both using jhbuild.
I like to think that F/OSS works because people keep re-inventing the wheel in new and obscure ways everytime they do something, so what follows is my rambling tale of cross-compiling-gtk-for-windows wheel reinvention.
## Cross compiling Gtk+ for Windows using Jhbuild
Starting with the work of Alberto Ruiz and Piotr Gaczkowski I thought I would setup a jhbuild environment to cross compile the Gtk+ stack. After a bit of fiddling I managed to get everything to build fine using mingw32 and jhbuild. The following files work successfully on Ubuntu gutsy and can build the latest stable releases of Gtk+/cairo/glib/libglade.
At this point I moved onto trying to build pygobject. This is where things got difficult. I tried a few different ways to get the cross compilation environment to see python. With some inspiration from this page on compiling glom for windows, I copied across the entire Python25 directory from a windows box and added it to the appropriate LDFLAGS and CFLAGS in jhbuild. This allowed pygobject to pass configure. However it now failed to build;
In file included from /usr/include/python2.5/Python.h:57,
from pygobject.h:5,
from pygobject-private.h:9,
from gobjectmodule.c:27:
/usr/include/python2.5/pyport.h:246:24: sys/select.h: No such file or directory
I went back to the windows machine and checked to see if sys/select.h was present in mingw. No luck. OK at this point I was stuck. Compiling wasn't looking likely, and I still wasnt even confident that if it did compile it would manange to actually link and run (due to different compiler versions and platforms, etc). I googled for a bit and saw that its now possible to build python extensions using mingw32 and that people had managed to cross compile python using mingw. Hmm, I pondered..... 'lets cross compile Python25 using mingw and then build pygobject using that.' Furthur googling revealed this python bug+patch for cross compiling using mingw. This is going to be easy.......
I added a new section to my modules file that would apply the patch to the Python 2.5.1 before building it. YOU FAIL AGAIN JOHN.
checking for %zd printf() format support... configure: error: cannot run test program while cross compiling
Hmm. I tried several strategies to get around this (including supplying a config.cache file with ac_cv_printf_zd_format=yes) but with no luck. You can see my plea for help on the bug report.......
At this point an entire day of my life had been irrevocably taken from me. I retired to bed. I would not let windows beat me....
## Native compilation of Gtk+ for Windows using Jhbuild
OK. At this point I thought I might as well start again, but compile natively on windows using mingw and msys. In hindsight it probbably would have been easier to follow most of the instructions for glom verbaim, but I decided to continue my quest at wheel re-invention.
I read that Alberto was thinking about ways to make Jhbuild work on windows - a good goal. Starting with his patch on that bug report I modified it slightly so that tar, gunzip and friends wouldn't need to be installed. Furthur to that I set about hacking up some patches to allow jhbuild to at least run on windows. A few hours later and I was sure that this was going to take a few more hours :-). I now had a working (ish) minimal easy to set up windows build environment according to these instructions..... or so I thought.
Jhbuild managed to successfully parse my minimal jhbuildrc and module files, download and untar iconv but then it failed. Basically there is considerable work and thought needed to see how this should operate in msys/cygwin. The problem is already explained in part here, but I will summarise.
Python's os.path and friends do a good job at converting paths to the native system format. Unfortunately the msys and cygwin shells also convert paths. For instance msys automagically converts /foo/bar to C:\msys\foo\bar. Basically it means that python converts paths to windows format, but msys likes them in unix format (because its a unix shell environment). This results in files not getting found, and gross composite paths like --prefix=C:\foo\bar/baz/bob getting passed to configure.
So, I had a bit of a look at how this could be solved in Jhbuild. I guess there are a few strategies
1. Create a whole bunch of utility functions join_path(), prepend_path(), etc. And call these instead of the system ones and only escape to windows format if you are running in windows, and not running in windows just kidding you are really running in cygwin haha.
2. Remove all os.path and friends calls. Be really naive and hard code all path operations to use unix semantics. Then explictly note that Jhbuild on windows must be run from within a unix shell like msys/bash or cygwin/bash.
3. Magic. Come up with some sort of paranormal event that would win GNOME \$1 million dollars which could then pay a developer to fix all this for me.
## Conclusion
Well things didn't work out as well as I hoped. I will probbably go and compile everything without jhbuild and be happy. I did learn that;
• Jhbuild on windows is a worthwhile cause. It would really help in automatically (jhautobuild) testing things like glib and GIO (at least giving devs a compile yes/no signal)
• It could make generating the latest tarballs really easy, perhaps even sharing the same modulesets as those maintained by the release team
• For extra bling it could even automatically create installers by tracking installed files using a strategy similar to checkinstall.
Help, thoughts or advice appreciated. For all the luck I have had the last few days I would not be surprised if I have missed something fundamentally obvious to this whole process. Heck if some fairy was to drop a pygoocanvas installer for windows in my mail box then I would be super happy. Oh and did I mention that im really looking forward to gio! | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5046407580375671, "perplexity": 3112.760189887157}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-15/segments/1397609532480.36/warc/CC-MAIN-20140416005212-00400-ip-10-147-4-33.ec2.internal.warc.gz"} |
http://www.lehigh.edu/~zhh210/research.html | ## Publications
[1] A Globally Convergent Primal-Dual Active-Set Framework for Large- Scale Convex Quadratic Optimization
F. E. Curtis, Z. Han, and D. P. Robinson, Computational Optimization and Applications (COAP), 2014.
[2] Globally Convergent Primal-Dual Active-Set Methods with Inexact Subproblem Solves
F. E. Curtis, Z. Han, Optimization Online, 2014(under review).
## Notes
On Optimization
[1] A Note on Inexact Newton's Method
- A proof of global convergence in solving unconstrained nonlinear optimization problem $$\min_{x\in\mathbb R^n}\ f(x)$$ by applying inexact Newton's method on $$\nabla f(x) = 0$$.
[2] Counterexamples in plain primal-dual active-set method
- For mathematicians, the greatest despair might be proposing a deceptively simple conjecture yet has to disprove it after many months of travail. But coming up empty-handed is a vital and oft-overlooked part of research. Each negative result rules out certain theories and strengthens others, shrinking the conceptual space in which the reality can be hiding.
On Numerical Methods
[1] Bounds on the Inverse of Nonnegative Matrix
- An interactive play to show that $$f_n:=\displaystyle\sum_{i=0}^n (I-H)^n$$ approximates $$H^{-1}\in\mathbb R^{n\times n}$$ in the limit. Certain assumptions on $$H$$ yields the interesting interlacing behavior that $$\cdots < f_{2k+1} < f_{2k+3} <\cdots < H^{-1} < \cdots < f_{2k+2} < f_{2k}<\cdots$$ for $$k\in \mathbb N$$.
[2] Submatrix's Inverse and Inverse's Submatrix: A Note on M-matrix
- Suppose $$H\in\mathbb R^{n\times n}\succ 0$$. Can we decide which one of $$\|(H^{-1})_{\mathcal I\mathcal I}\|$$ and $$\|(H_{\mathcal I\mathcal I})^{-1} \|$$ is larger? Yes, if $$H$$ is an $$M$$-matrix or $$\|\cdot\|$$ is Euclidean norm; No, at least for some positive definite matrices on $$\|\cdot \|_{1}$$ or $$\|\cdot \|_{\infty}$$.
[3] An application of Hölder’s inequality
- Hölder’s inequality is applied to obtain a cheaply computable upper bound of $$|H^{-1}r|$$.
## Slides
[1] A Primal-Dual Active-Set Algorithm for a Class of Large-Scale Convex Quadratic Optimization Problems
To appear for INFORMS Annual Conference. San Francisco, CA. Nov 2014.
List of publications, notes, thoughts, etc. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9431150555610657, "perplexity": 2835.930823782948}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-22/segments/1432207929561.98/warc/CC-MAIN-20150521113209-00094-ip-10-180-206-219.ec2.internal.warc.gz"} |
https://support.10xgenomics.com/single-cell-dna/software/pipelines/latest/advanced/references | Software › pipelines
# Reference Support
Cell Ranger DNA provides pre-built GRCh38 (human), GRCh37 (human) and GRCm38 (mouse) reference packages for use with the pipeline. These references come packaged with GENCODE annotations. Following current conventions, these references have the following properties:
• GRCh38 (human): Chromosome names begin with "chr". The FASTA is obtained from this location, and the annotations are GENCODE V28 obtained from here. This build has no alt loci and does not have a decoy, but does have a Epstein-Barr virus decoy.
• GRCh37 (human): Chromosome names do not begin with "chr". The FASTA is obtained from this location, and the annotations are GENCODE V25 (Ensembl V87) obtained from here. This version of GRCh37 has a decoy sequence (hs37d5).
• GRCm38 (mouse): The FASTA is obtained from this location, and the annotations are GENCODE M17 obtained from here. This build has no alt loci.
At this time, only these human and mouse references have seen extensive testing.
# Making a Reference Package
Cell Ranger DNA comes packaged with the command mkref which will construct a reference. mkref requires a single FASTA file containing the reference genome sequence and contig_defs.json file. Any alternate haplotype sequence records should be omitted from the FASTA file since these will result in a greater fraction of the genome being unmappable. An optional GTF may also be provided, which will be used solely to provide gene annotations for visualization using Loupe scDNA Browser:
$cellranger-dna mkref <fasta_file> <contig_defs_file> [--gtf=<file.gtf.gz>] After this process has completed, there should be a new folder called refdata-$GENOME (where $GENOME is the FASTA filename without the filetype suffix) in the current directory with the following structure: $ tree refdata-$GENOME ├── fasta │ ├── genome.fa │ ├── genome.fa.amb │ ├── genome.fa.ann │ ├── genome.fa.bwt │ ├── genome.fa.fai │ ├── genome.fa.flat │ ├── genome.fa.gdx │ ├── genome.fa.pac │ └── genome.fa.sa │ └── contig-defs.json ├── genes ├── genome ├── regions └── snps ## Contig Defs file A contig_defs.json file must be provided. This file is necessary to determine which contigs in the input FASTA are considered primary contigs, as well as keeping track of sex-chromosomes, and non-nuclear sequences. The contig_defs.json file has the following keys: • species_prefixes: This field is not currently used and can be omitted. If this field is present, the contig names must match the species prefixes in the pattern ${prefix}_\${contig}. As an example, if species_prefixes is ["GRCh38"], then primary_contigs would have the names ["GRCh38_chr1", ...].
• primary_contigs: A list of primary contigs. Copy number variants will only be called on primary contigs. Primary contigs should be at least 10 megabases in length.
• sex_chromosomes: A key-value list defining expected copy number for sex chromosomes in the male and female case. This field is not currently used and may be omitted.
• non_nuclear_contigs: A list of non-nuclear contigs such as the mitochondrial sequence. This field is not currently used and may be omitted.
As an example, here is the contig_defs.json that comes packaged with the GRCh38 reference:
{
"species_prefixes": [""],
"primary_contigs": [
"chr1", "chr2", "chr3","chr4", "chr5", "chr6", "chr7", "chr8", "chr9", "chr10", "chr11", "chr12", "chr13", "chr14", "chr15", "chr16", "chr17", "chr18", "chr19", "chr20", "chr21", "chr22", "chrX", "chrY"
],
"sex_chromosomes": {
"_male": {
"chrX": 1,
"chrY": 1
},
"_female": {
"chrX": 2,
"chrY": 0
}
},
"non_nuclear_contigs": ["chrM"]
}
## GTF Gene Annotations file
A GTF file may be provided to mkref to facilitate visualization in Loupe scDNA Browser. This file may be provided to mkref gzipped or not, and only annotations with gene_type or gene_biotype attribute of protein_coding or pseudogene are considered.
• Cell Ranger DNA v1.0 (latest) | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.25267282128334045, "perplexity": 18790.870900093487}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-09/segments/1550249500704.80/warc/CC-MAIN-20190223102155-20190223124155-00622.warc.gz"} |
Subsets and Splits