url
stringlengths 14
1.76k
| text
stringlengths 100
1.02M
| metadata
stringlengths 1.06k
1.1k
|
|---|---|---|
https://publiclab.org/questions/vinushi1995/07-21-2019/pms7003-with-arduino-mega2560
|
# Question: PMS7003 with Arduino MEGA2560
by vinushi1995 |
Hello, a first timer here. Thanks in Advance for anyone kind enough to offer me advice.
i have been trying to make an air quality monitor using the Aircasting app. To measure particulate matter i got the PMS7003 Sensor. Does anyone know a proper wiring diagram and a code that works with arduino? I've been trying some codes but have been encountering problems in most of them. This is the latest code i've been using and it seems to be giving values in 100s which is very high
# include SoftwareSerial mySerial(10,11); // Arudino Uno port RX, TXvoid setup() { // for debuging Serial.begin(115200); // Use software serial mySerial.begin(9600);}void loop() { // put your main code here, to run repeatedly: static int CheckFirst=0; static int pm_add[3][5]={0,}; static int pm_old[3]={0,}; int chksum=0,res=0;; unsigned char pms[32]={0,}; if(mySerial.available()>=32) { for(int j=0; j<32 ; j++){ pms[j]=mySerial.read(); if(j<30) chksum+=pms[j]; } if(pms[30] != (unsigned char)(chksum>>8) || pms[31]!= (unsigned char)(chksum) ){ } if(pms[0]!=0x42 || pms[1]!=0x4d ) Serial.print("Dust raw data debugging : "); Serial.print("1.0ug/m3:"); Serial.print(pms[10]); Serial.print(pms[11]); Serial.print(" "); Serial.print("2.5ug/m3:"); Serial.print(pms[12]); Serial.print(pms[13]); Serial.print(" "); Serial.print("10ug/m3:"); Serial.print(pms[14]); Serial.println(pms[15]); } delay(2000);}
<br>
Good to see your project. 1. In the code the TX , RX pins mention Board associated as Arduino UNO but you are using Mega. Kindly check the pin connections. RX pin of Board as to be TX pin of PM sensor and same for TX as well.
1. Links where you can find detailed information 👍 https://publiclab.org/notes/cfastie/11-28-2018/nano-particle-monitoring
2. This link is from Adafruit. Check for the board and PM sensor variant and modify accordingly. https://learn.adafruit.com/pm25-air-quality-sensor?view=all
Hope this helps.
Is this a question? Click here to post it to the Questions page.
@silentsairam Thank you so much for the advice! I sure will look into it. 😃
Hi @vinushi1995..did you get your project working? I am having a similar problem with the PMS7003. I am using similar code to yours. It does appear to work with the PMS5003 which is similar but a bit larger footprint. But when I use the 7003 with the same code I also am getting values that are 10x-20x larger than expected. Not sure what is causing this as it is claimed that the two sensors are electrically identical and use the same data protocol. Appreciate any thoughts/suggestions from forum members.
Is this a question? Click here to post it to the Questions page.
|
{"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": 0.17764392495155334, "perplexity": 5001.353273788348}, "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/1593655887046.62/warc/CC-MAIN-20200705055259-20200705085259-00407.warc.gz"}
|
https://www.esaral.com/q/a-certain-household-has-consumed-250-units-of-energy-during-a-month
|
# A certain household has consumed 250 units of energy during a month.
Question.
A certain household has consumed 250 units of energy during a month. How much energy is this in joules ?
Solution:
Energy consumed in a month
$=250$ units $=250 \mathrm{kWh}$
$=250 \times 3.6 \times 10^{6}=9 \times 10^{8} \mathrm{~J}$
Leave a comment
Free Study Material
|
{"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": 0.7060368657112122, "perplexity": 3858.6873101821557}, "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-2023-14/segments/1679296943698.79/warc/CC-MAIN-20230321131205-20230321161205-00409.warc.gz"}
|
http://mathhelpforum.com/calculus/87042-error-bound-taylor-polynomial.html
|
# Math Help - error bound taylor polynomial
1. ## error bound taylor polynomial
Use taylor's theorem to bound the error in approximating the function f(x) = e^x with the maclaurin series M_6(x) on the interval [-1,1]
The formual for this type of thing is
$|f(x) - P_n(x)| \leq \frac {K_{n + 1}} {(n + 1)!}|x - x_0|^{n + 1}$
the max bound is $K_{n + 1} = e^1$ $x_0 =0, n = 6$
$\frac {e^1} {7!} |-1|^7 \approx 5.39 * 10^-4$
is this correct?
2. Originally Posted by diroga
The formual for this type of thing is
$|f(x) - P_n(x)| \leq \frac {K_{n + 1}} {(n + 1)!}|x - x_0|^{n + 1}$
the max bound is $K_{n + 1} = e^1$ $x_0 =0, n = 6$
$\frac {e^1} {7!} |-1|^7 \approx 5.39 * 10^{-4}$
is this correct?
More or less, but you need to improve your notation and explain what things are.
CB
|
{"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": 8, "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": 0.997075617313385, "perplexity": 1483.6161056179758}, "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-2014-41/segments/1412037663754.5/warc/CC-MAIN-20140930004103-00190-ip-10-234-18-248.ec2.internal.warc.gz"}
|
https://ta.wikipedia.org/wiki/%E0%AE%8F%E0%AE%B0%E0%AF%8D%E0%AE%9F%E0%AF%8D%E0%AE%9A%E0%AF%81
|
# ஏர்ட்சு
Lights flash at frequency f = 0.5 Hz (Hz = hertz), 1.0 Hz or 2.0 Hz, where ${\displaystyle x}$ Hz means ${\displaystyle x}$ flashes per second. T is the period and T = ${\displaystyle y}$ s (s = seconds) means that ${\displaystyle y}$ is the number of seconds per flash. T மற்றும் f இரண்டும் பெருக்கல் நேர்மாறுகள்: f = 1/T மற்றும் T = 1/f.
|
{"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 4, "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": 0.8937100172042847, "perplexity": 4177.737631363684}, "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/1603107904039.84/warc/CC-MAIN-20201029095029-20201029125029-00169.warc.gz"}
|
http://math.stackexchange.com/questions/137504/prove-that-ri-r-in-r-mid-xr-in-i-text-for-every-x-in-r-is-an-ide
|
# Prove that $[R:I] =\{r \in R\mid xr \in I\text{ for every }x \in R\}$ is an ideal of $R$ that contains $I$
If $I$ is an ideal in a ring $R$ let $[R:I] =\{r \in R\mid xr \in I\text{ for every }x \in R\}$. How can I show that $[R:I]$ is an ideal of $R$ which contains $I$.
-
Welcome to math.SE: since you are a new user, I wanted to let you know a few things about the site. In order to get the best possible answers, it is helpful if you say what your thoughts on it are so far; this will prevent people from telling you things you already know, and help them write their answers at an appropriate level. – Zev Chonoles Apr 27 '12 at 0:19
Hint: First show that I is contained in here (use the fact that I is an ideal). Then the ideal part should follow immediately, since for $r\in [R : I]$ and any $x\in R$ we have $xr \in I \subset [R:I]$ – Deven Ware Apr 27 '12 at 0:39
You have swapped the "numerator" and the "denominator" in your definition of what is sometimes called a colon ideal. The correct notation is $$(I:R) =\{r \in R\mid xr \in I\text{ for every }x \in R\}$$ – Georges Elencwajg Apr 27 '12 at 15:02
Containment: You need to show that elements of $I$ have the necessary property, ie. for all $x\in I$, $xr\in I$ for each $x\in R$.
Both follow directly from the definitions: once you grok the definition of Ideal and $[R:I]$ it should be pretty quick.
Bonus question: Show that $I=[R:I]$ if $R$ contains $1$.
|
{"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": 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": 0.8657273650169373, "perplexity": 221.69007816383098}, "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-2014-23/segments/1406510276250.57/warc/CC-MAIN-20140728011756-00413-ip-10-146-231-18.ec2.internal.warc.gz"}
|
http://advances.sciencemag.org/content/2/6/e1600295.full
|
Research ArticleCONDENSED MATTER PHYSICS
# A strongly robust type II Weyl fermion semimetal state in Ta3S2
See allHide authors and affiliations
Vol. 2, no. 6, e1600295
## Abstract
Weyl semimetals are of great interest because they provide the first realization of the Weyl fermion, exhibit exotic quantum anomalies, and host Fermi arc surface states. The separation between Weyl nodes of opposite chirality gives a measure of the robustness of the Weyl semimetal state. To exploit the novel phenomena that arise from Weyl fermions in applications, it is crucially important to find robust separated Weyl nodes. We propose a methodology to design robust Weyl semimetals with well-separated Weyl nodes. Using this methodology as a guideline, we search among the material parameter space and identify by far the most robust and ideal Weyl semimetal candidate in the single-crystalline compound tantalum sulfide (Ta3S2) with new and novel properties beyond TaAs. Crucially, our results show that Ta3S2 has the largest k-space separation between Weyl nodes among known Weyl semimetal candidates, which is about twice larger than the measured value in TaAs and 20 times larger than the predicted value in WTe2. Moreover, all Weyl nodes in Ta3S2 are of type II. Therefore, Ta3S2 is a type II Weyl semimetal. Furthermore, we predict that increasing the lattice by <4% can annihilate all Weyl nodes, driving a novel topological metal-to-insulator transition from a Weyl semimetal state to a topological insulator state. The robust type II Weyl semimetal state and the topological metal-to-insulator transition in Ta3S2 are potentially useful in device applications. Our methodology can be generally applied to search for new Weyl semimetals.
Keywords
• Weyl fermion
• Fermi arc
• Topology
## INTRODUCTION
The rich correspondence between high-energy particle physics and low-energy condensed matter physics has been a constant source of inspiration throughout the history of modern physics (1). This has led to important breakthroughs in many aspects of fundamental physics, such as the Planck constant and blackbody radiation, the Pauli exclusion principle and magnetism, and the Anderson-Higgs mechanism and superconductivity, which, in turn, helped us understand materials that can lead to important practical applications. Recently, there has been significant interest in realizing high-energy particles in solid-state crystals. The discovery of massless Dirac fermions in graphene and on the surface of topological insulators has taken the center stage of research in condensed matter and materials science for the past decade (25). Weyl semimetals (621) are crystals whose quasi-particle excitation is the Weyl fermion (6), a particle that played a crucial role in the development of quantum field theory and the Standard Model but has not yet been observed as a fundamental particle in nature. Weyl fermions have a definite left- or right-handed chirality and can be combined in pairs of opposite chirality to generate a massless Dirac fermion. In a Weyl semimetal, the chirality associated with each Weyl node can be understood as a topologically protected charge, thus broadening the classification of topological phases of matter beyond insulators. The presence of parallel electric and magnetic fields can break the apparent conservation of the chiral charge, which results in the condensed matter version of the chiral anomaly, making a Weyl semimetal, unlike ordinary nonmagnetic metals, more conductive with an increasing magnetic field (22, 23). Weyl nodes are extremely robust against imperfections in the host crystal and are protected by the crystals’ inherent translational invariance (12). This gives rise to an exceptionally high electron mobility, suggesting that Weyl semimetals may be used to improve electronics by more efficiently carrying electric currents (24). Because Weyl fermion quasi-particles are naturally spin-momentum locked (12, 14, 15) and superconductivity in these materials may exhibit non-Abelian statistics (2527), they may also be exploited to realizing new applications, such as in spintronics and quantum computers. Furthermore, a monolayer [the two-dimensional (2D) limit] of time-reversal breaking Weyl semimetals can host quantized anomalous Hall (or spin Hall) current without an external magnetic field. To make these novel phenomena experimentally accessible, especially under ambient conditions so that they can be used in device applications, a robust Weyl semimetal with well-seperated Weyl nodes is critically needed.
Recently, the first Weyl semimetal was discovered in the TaAs (tantalum arsenide) family (1719, 21, 2837). However, research progress is still significantly held back because of the lack of robust and ideal material candidates. In a Weyl semimetal, Weyl nodes of opposite chirality are separated in momentum space. The degree of separation between Weyl nodes provides a measure of the “topological strength” of the Weyl phase (38) that one has to overcome to annihilate the Weyl fermions in pairs. A large k-space separation of the Weyl nodes gurantees a robust and stable Weyl semimetal state, which is a prerequisite for observing the many exotic phenomena predicted to be detectable in spectroscopic and transport experiments. Therefore, it is of critical importance to find robust and ideal Weyl semimetals, which have fewer Weyl nodes and more importantly whose Weyl nodes are well separated in momentum space and are located near the chemical potential in energy.
Moreover, in contrast to the Weyl fermions in high-energy physics, which travel exactly at the speed of light and strictly obey Lorentz invariance, the emergent Weyl fermions in a Weyl semimetal are not subject to these restrictions. It has been recently proposed that the emergent Weyl fermions in a Weyl semimetal can be classified into two types (39). The type I Weyl fermions, which have been realized in TaAs (1719, 21, 2837), respect Lorentz symmetry and have a typical conical dispersion. On the other hand, the type II Weyl fermions strongly violate Lorentz symmetry and manifest in a tilted-over cone in energy-momentum space. Such a type II Weyl semimetal state not only provides a material platform for testing exotic Lorentz-violating theories beyond the Standard Model in tabletop experiments but also paves the way for studying novel spectroscopic and transport phenomena specific to type II Weyl fermions, including the chiral anomaly (whose transport response strongly depends on the direction of the electric current), an antichiral effect of the chiral Landau level, a modified anomalous Hall effect, and emergent Lorentz invariant properties due to electron-electron interaction (3841). To date, the type II Weyl semimetal state has only been suggested in W1−xMoxTe2 (38, 39) and observed in LaAlGe (41). Therefore, it is of importance to search for new type II Weyl semimetals.
Here, we propose a methodology to design and search for robust Weyl semimetals with well-separated Weyl nodes. Using this methodology as a guideline, we identify by far the most robust and ideal Weyl semimetal candidate in the single-crystalline compound tantalum sulfide (Ta3S2) with new and novel properties beyond TaAs. Crucially, our results show that Ta3S2 has the largest k-space separation between Weyl nodes among known Weyl semimetal candidates, which is about twice larger than the measured value in TaAs and 20 times larger than the predicted value in WTe2. Moreover, all Weyl nodes in Ta3S2 are of type II. Therefore, Ta3S2 is a type II Weyl semimetal. We further predict a novel topological metal-to-insulator transition from a Weyl semimetal state to a topological insulator state in Ta3S2. The robust type II Weyl semimetal state and the topological metal-to-insulator transition in Ta3S2 are potentially useful in device applications. Our methodology can be generally applied to search for new Weyl semimetals.
## RESULTS
We start by describing our methodology to design robust Weyl semimetals using well-separated Weyl nodes. It has been widely accepted that strong spin-orbit coupling (SOC) is a key ingredient to realizing topological states. Our methodology evades this commonly accepted point of view. We show that, to design robust Weyl semimetals with well-separated Weyl nodes, one needs to look for materials (i) that break space-inversion symmetry, (ii) that have small density of states (DOS) at the chemical potential, and (iii) that are already a Weyl semimetal in the absence of SOC. SOC, on the other hand, does not play a significant role in the whole consideration. We elaborate on our methodology in Fig. 1. Figure 1 (A and B) shows the previous way of looking for Weyl semimetals. Specifically, without SOC, the conduction and valence bands show some nodal crossings (which are not Weyl nodes). The inclusion of SOC splits each nodal point into a pair of Weyl nodes of opposite chiralities. In this way, the separation between the Weyl nodes is entirely determined by the SOC strength of the compound. For example, the first and the only Weyl semimetal in experiments, TaAs, belongs to this type (17, 19). TaAs has almost the strongest SOC that one could achieve in real materials. Even then, the separation was only barely resolved in experiments (19). Finding Weyl semimetals with larger separation than TaAs using the previous method is not possible. By contrast, in Fig. 1 (C and D), we present a new methodology. We propose to look for compounds that are already a Weyl semimetal without SOC (Fig. 1C). The inclusion of SOC will split each Weyl node into two nodes of the same chirality. In this way, SOC becomes irrelevant. The separation between the Weyl nodes of opposite chiralities is determined by the magnitude of the band inversion, which is not limited by the SOC strength and can be very large. Therefore, our new methodology can give rise to robust Weyl semimetals with well-separated Weyl nodes.
Using this methodology as a guideline, we have searched among the material parameter space and identified by far the most robust and ideal Weyl semimetal candidate in the inversion-breaking, single-crystalline compound Ta3S2 with new and novel properties beyond TaAs. Ta3S2 crystallizes in a base-centered orthorhombic structure (42, 43). Single crystals of this compound have been grown (42, 43), and transport experiments have indeed reported a semimetallic behavior (42). The lattice constants are a = 5.6051 Å, b = 7.4783 Å, and c = 17.222 Å, and the space group is Abm2 (# 39). There are 24 Ta atoms and 16 S atoms in a conventional unit cell (Fig. 2, A and B). It can be seen that the lattice lacks space-inversion symmetry, which is key to realizing the Weyl semimetal state in this time-reversal invariant system. Moreover, the system has two glide mirror symmetries associated with the y and z directions, that is, and , but it does not have any mirror symmetry along the x direction. The symmetry condition determines the number, energy, and momentum space configuration of the Weyl nodes in Ta3S2, which will be discussed below.
Figure 2 (D and F) shows the first-principles calculated band structure in the absence of SOC, from which it can be seen that the conduction and valence bands dip into each other, suggesting a semimetallic ground state. Particularly, we find that the conduction and valence bands cross each other without opening up a gap along the X-Γ-Z-X1 direction. Upon the inclusion of SOC (Fig. 2, E and G), the band structure is found to be fully gapped along all high-symmetry directions.
To search for the Weyl nodes in Ta3S2, we calculated the band structure throughout its Brillouin zone (BZ). In the absence of SOC (Fig. 3A), we found a line node on the ky = 0 plane, which is the band crossings along the Γ-X-Z-X1 direction, as shown in Fig. 2D. This line node is on the ky = 0 plane and is, therefore, protected by the mirror symmetry . In addition, we also found two pairs of Weyl nodes located on the kx = 0 plane (Fig. 3A). We determine the chirality of the Weyl node by computing the Berry curvature through a closed 2D manifold enclosing the node. Considering the available symmetries as discussed above, Ta3S2 has only one irreducible pair of Weyl nodes. The second pair is obtained by applying the mirror operation . In general, a mirror symmetry operation reflects a Weyl node on one side of the mirror plane to the mirror-reflected location on the other side while also flipping the sign of the chiral charge. Hence, it can be seen that the two pairs of Weyl nodes without SOC are directly related by the mirror operation . Upon the inclusion of SOC, each Weyl node without SOC splits into two spinful Weyl nodes of the same chirality. This is quite intuitive because each state without SOC should be considered as two states of opposite spins. For this reason, there are four pairs of Weyl nodes in the presence of SOC. Again, there is only one irreducible pair and the others are related by the mirror operations and . Also, because of the mirror symmetries, all the Weyl nodes have the same energy in Ta3S2. We show the dispersion away from a Weyl node along all three momentum space directions in Fig. 3 (C and D). It can be seen that the Weyl nodes in Ta3S2 are of type II (39), because the two bands that cross to form the Weyl nodes have the same sign of velocity along one momentum direction (in this case, ky). In the presence of SOC (Fig. 3D), the Weyl nodes are approximately 10 meV below the Fermi level, which is in contrast to the case in MoxW1−xTe2 systems (38, 39). This makes Ta3S2 more hopeful than MoxW1−xTe2 (38, 39) for observing the type II Weyl nodes by photoemission experiments. The k separation of the Weyl nodes (Fig. 3D) in Ta3S2 is as large as ~ 0.15 Å−1. This is by far the largest among known Weyl semimetal candidates and, in fact, twice larger than the measured value in TaAs (about 0.07 to 0.08 Å−1) (19) and 20 times larger than the predicted value in WTe2 (~ 0.007 Å−1) (39). The fact that the Weyl nodes are well separated in momentum space and the fact that they are located near the chemical potential make Ta3S2 by far the most robust and ideal Weyl semimetal candidate for observing and realizing the novel Weyl physics in both spectroscopic and transport experiments.
Another signature of the Weyl semimetal state is the Fermi arc electron states on the surface of the crystal. Figure 4 shows the calculated surface state electronic structure on the surface of Ta3S2. The calculated surface state Fermi surface (Fig. 4, A and D) shows a rich structure, including both topological Fermi arcs and topologically trivial surface states. There are finite projected bulk Fermi surfaces as shown by the shaded areas in Fig. 4C, because all the Weyl nodes are type II. It is known that, at the energy of a type II Weyl node, the bulk Fermi surface is not an isolated point but a touching point between an electron and a hole pocket (39). The Fermi surface does not respect mirror symmetry along the or axis. As shown in Fig. 4A, is the projection of the kx = 0 plane, which is not a mirror plane. is the projection of the ky = 0 plane, which is indeed a mirror plane. However, it corresponds to a glide mirror operation . Therefore, the surface breaks the glide mirror symmetry. To visualize the Fermi arc surface states, Fig. 4B shows the energy dispersion cut along Cut1 (denoted by the red dashed line in Fig. 4A). In both box 1 and box 2, we clearly see that a surface state is terminated directly onto a Weyl node, which is the touching point between the shaded areas. This calculation demonstrates the existence of the Fermi arc surface states. Specifically, we label the two surface states in box 1 (upper right panel in Fig. 4B) as β and α from left to right. We see that β is the Fermi arc. In Fig. 4D, we show the high-resolution Fermi surface zoomed in near the point. The Weyl node that corresponds to box 1 is the black dot that is directly above the bottom-leftmost black dot in Fig. 4D. The two surface states, α and β, are identified and, indeed, the left surface state, β, is the Fermi arc terminating onto this Weyl node. Through similar analyses, we can determine that α is the Fermi arc corresponding to the bottom-leftmost Weyl node. On the basis of the above analyses, we show the determined Fermi arc connection in Fig. 4E. We also emphasize that the topological band theory of the Weyl semimetal phase only requires that the number of Fermi arcs that are terminated on a given projected Weyl node must be equal to the absolute value of its chiral charge. The detailed connectivity pattern can vary based on surface conditions, such as surface potential, surface relaxation, and surface density. Hence, the purpose of Fig. 4E is to show the existence of Fermi arcs, which are a key signature of the Weyl semimetal state in Ta3S2. The details of the surface electronic structure, including the connectivity pattern, will depend on the surface conditions, which have to be determined by experiments.
Now, we show the topological metal-to-insulator transition in Ta3S2 in Fig. 5. To best visualize the transition, we show the band dispersion along a cut that goes through an irreducible pair of Weyl nodes (as defined by the red dashed line in Fig. 6D). As shown in Fig. 5A, we show this cut as a function of different values of the lattice constant b. At the original lattice constant b′ = b, we indeed see a pair of type II Weyl nodes, as expected. As we increase the lattice constant by 3.0% (b′ = 1.030b), we see that Weyl nodes approach each other and their separation decreases by half. As we further increase the lattice constant to b′ = 1.040b, the two Weyl nodes annihilate each other and the band structure becomes fully gapped. By a careful calculation, we determined that the lattice constant corresponding to the critical point is b′ = 1.037b. The resulting fully gapped state for b′ > 1.037b has two possible fates, that is, either a trivial insulator or a topological insulator. We have calculated the Wilson loop of the Wannier function centered on the kz = 0 plane and on the kz = π plane (Fig. 5B), from which we determined that the gapped state for b′ > 1.037b is a topological insulator and its indices are (1; 000). Therefore, by increasing the lattice constant b, one can realize a topological phase transition from a Weyl semimetal state to a topological insulator state in Ta3S2. The corresponding evolution of the surface electronic structure is shown in Fig. 5C for the case of the surface. The projected Weyl nodes of opposite chirality, which are connected by the Fermi arcs, approach each other and eventually meet on the axis where they annihilate. The resulting surface has a single surface state whose Fermi surface encloses the Kramers point , which also demonstrates the topological insulator state.
Besides the topological phase transition, we found that the system exhibits other important tunabilities. Specifically, it can be seen that although the Weyl nodes at the original lattice constant are type II, they become type I at b′ = 1.030b, because the Weyl node is now formed by two bands with the opposite sign of velocity (Fig. 5A). Therefore, there is a transition from type II Weyl fermions to type I Weyl femions as one increases the lattice constant b. Moreover, we note that the energy of the bands in Fig. 5A shifts across the chemical potential as one increases b. Therefore, specific values of the lattice constant b also exist, at which important features will be moved exactly onto the chemical potential. We focus on two important features, that is, the Weyl nodes and the Van Hove singularities (VHSs) that arise from the Weyl cones (see the middle panel of Fig. 5A). Placing the Weyl nodes at the Fermi level is very meaningful because they are monopoles of Berry curvature. Thus, any novel phenomenon that arises from the chirality of the Weyl fermions, such as the chiral anomaly, will become most significant when the Weyl nodes are at the Fermi level. Putting the VHS at the Fermi level can also be interesting because the VHS is due to a saddle point in the band structure, which means that the DOS will show a maxima at the energy of the VHS. An enhanced DOS is favorable for inducing correlated physics, such as superconductivity or magnetism. A detailed phase diagram is shown in Fig. 5C.
We show that the band structure of Ta3S2 exhibits a new type of critical point as one decreases the lattice constant c or increases the SOC λ. As discussed above, under ambient conditions, the conduction and valence bands only touch each other at eight discrete points in the BZ, which are the eight Weyl nodes. Here, we show that decreasing the lattice constant c or increasing the SOC λ leads to the generation of new Weyl nodes. Representing the critical point for this process is the critical value for the lattice constant c or SOC λ corresponding to the point where the conduction and valence bands just touch, ccritical = 0.98c or λcritical = 1.027 λ. Taking the critical point of λcritical = 1.027 λ as the example, we show the k-space locations of these newly emerged band touchings by the green dots in Fig. 6D. We find that the critical point band structure is novel. Specifically, the dispersion along kz near the band touching behaves like two downward-facing parabolas. These two parabolas touch at their vertex, which forms the band touching point. This is distinct from the critical points associated with any previously known Weyl semimetal candidates. For example, the critical point band structure of TaAs can be thought of as two parabolas of opposite directions, one facing up and the other facing down (Fig. 6A). Then, entering the Weyl phase from the critical point essentially means “pushing” the two parabolas “into” each other so that they cross to form the two Weyl nodes. The situation in the MoxW1−xTe2 system is very similar, the only difference being that the direction of the parabolas is titled away from being vertical (Fig. 6B). By contrast, in Ta3S2, we have two parabolas that face the same direction (Fig. 6C). A distinct and unique property of the new critical point is that it leads to a saddle point in the band structure, giving rise to a VHS. The saddle point behavior can be seen from the band dispersions shown in Fig. 6E. If one focuses on the conduction band in Fig. 6E, then the touching point is the energy minima for the dispersions along the kx, ky directions, but it is the energy maxima along the kz direction. The saddle point band structure brings about a VHS, which generates a maxima in the DOS and a divergence in the first derivative of the DOS at the energy of the VHS, as shown in Fig. 6G.
## DISCUSSION
We elaborate the meaning of the robust and ideal Weyl semimetal candidate as emphasized in our paper. First, we mean that the realization of the candidate is likely to be experimentally feasible. This involves the following critical conditions: (i) the prediction is based on the realistic crystal structure, which means that the compound does crystallize in the proposed crystal structure under ambient conditions; (ii) the prediction does not require fine-tuning of the chemical composition or the magnetic domains; and (iii) the Weyl nodes are not located at energies far above the chemical potential such that they can be observed by photoemission. This was the case for our prediction of TaAs (17), which has now been realized (19). This is also the case here for Ta3S2, which demonstrates the experimental feasibility of our proposal on Ta3S2. Second, and more importantly, the term “robust” also refers to a large separation of the Weyl nodes in momentum space because, as discussed above, the separation of the Weyl nodes provides a measure of a Weyl semimetal’s topological strength. We again highlight that Ta3S2 has the largest k-space separation between Weyl nodes among known Weyl semimetal candidates, which is about twice larger than that of TaAs. This will greatly help resolve the Weyl nodes in various spectroscopic measurements, such as photoemission and scanning tunneling spectroscopy. This will also make it easier to probe the chiral anomaly and other Berry curvature monopole physics in electrical and optical transport experiments.
Finally, we compare the topological metal-to-insulator transition in Ta3S2 with transitions predicted in other Weyl candidates (44, 45). Theoretical work by Nozaki et al. (43) predicted the topological phase transitions from a trivial band insulator to a Weyl semimetal and then to a topological insulator by varying the chemical composition x in LaBi1−xSbxTe3 or applying external pressure to BiTeI. However, the composition or pressure range that corresponds to the Weyl semimetal phase is predicted to be extremely narrow (43). Hence, it requires ultra–fine-tuning, which is very difficult in experiments. Also, LaBi1−xSbxTe3 has never been grown in the crystal structure required by the proposal of Nozaki et al. (43) at least in the single-crystal form. The work by Liu et al. (45) proposed similar transitions in the β-Bi4Br4 under external pressure. To induce a Weyl semimetal phase in the β-Bi4Br4 crystal structure that has inversion symmetry, a hypothetical inversion-breaking term was assumed in the calculation. By contrast, Ta3S2 is an inversion-breaking, single-crystalline compound. Single-crystalline Ta3S2 samples have been grown (42, 43). The Weyl semimetal state is stable and does not require fine-tuning. We propose the following three methods for increasing the b lattice constant: (i) It can be achieved by applying external force. The method has been demonstrated by Zheng et al. (46). As an order-of-magnitude estimate, we calculated the required force by first-principles calculations and obtained an approximately 6-GPa force for an approximately 4% increase in the b lattice constant. Force in this range is experimentally feasible and the change of the lattice constant can be monitored by transmission electron microscopy (46). (ii) It may also be achieved by growing a Ta3S2 film onto a substrate with lattice mismatch. (iii) It may be achieved by growing samples with isoelectronic chemical substitution, such as Ta3(S1−xSex)2. These facts highlight that Ta3S2 is, to date, the most ideal platform not only for advancing our understanding of Weyl semimetals and Weyl physics but also for facilitating the exploitation of the exotic and novel properties in future device applications.
## MATERIALS AND METHODS
First-principles calculations of Ta3S2 were performed using the OpenMX code based on norm-conserving pseudopotentials generated with multireference energies and optimized pseudoatomic basis functions (47, 48). The SOC was incorporated through j-dependent pseudopotentials, and the generalized gradient approximation was adopted for the exchange-correlation energy functional (49, 50). For each Ta atom, three, two, two, and one optimized radial function were allocated for the s, p, d, and f orbitals (s3p2d2f1), respectively. For each S atom, s3p2d2f1 was adopted. The cutoff radius for both Ta and S basis functions was 7 bohr, and the cutoff energy was 1000 rydberg. A k-point mesh of 13 × 11 × 11 for the primitive unit cell and the experimental lattice parameters were adopted in the calculations. We used the Ta d and S p orbitals to construct the Wannier functions. We calculated the surface spectral weight of a semi-infinite slab using the iterative Green’s function method from the Wannier function–based tight-binding model. We did not choose the (001) and the (010) surfaces because pairs of Weyl nodes of opposite chirality are projected onto each other on these two surfaces (Fig. 3B). Hence, the (001) and the (010) surfaces do not carry net-projected chiral charge and are not expected to show Fermi arcs. Because the purpose of the surface calculations (Fig. 4) was to demonstrate the existence of Fermi arcs, the usage of the surface is proper and sufficient.
## SUPPLEMENTARY MATERIALS
Supplementary Text
fig. S1. Fermi arc surface states and Weyl nodes on the surface without SOC.
fig. S2. Distribution of Weyl nodes in Ta3S2.
This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial license, which permits use, distribution, and reproduction in any medium, so long as the resultant use is not for commercial advantage and provided the original work is properly cited.
## REFERENCES AND NOTES
Acknowledgments: Funding: Work at Princeton University was supported by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES), under DE-FG-02-05ER46200. Work at the National University of Singapore was supported by the National Research Foundation (NRF), Prime Minister’s Office, Singapore, under its NRF fellowship (NRF award no. NRF-NRFF2013-03). T.-R.C. and H.-T.J. were supported by the National Science Council, Taiwan. H.-T.J. also thanks the National Center for High-Performance Computing, Computer and Information Network Center, National Taiwan University, and the National Center for Theoretical Sciences, Taiwan, for technical support. Work at Northeastern University was supported by U.S. DOE/BES grant no. DE-FG02-07ER46352 and benefited from Northeastern University’s Advanced Scientific Computation Center and the National Energy Research Scientific Computing Center supercomputing center through DOE grant no. DE-AC02-05CH11231. S.M.H., G.C., and T.R.C. acknowledge their visiting scholar positions at Princeton University, which were funded by the Gordon and Betty Moore Foundation EPiQS Initiative through grant GBMF4547 (Hasan). Author contributions: Preliminary material search and analysis were performed by S.-Y.X. Theoretical analysis and computations were performed by G.C., S.-M.H., C.-C.L., T.-R.C., H.-T.J., A.B., and H.L. G.C. made the figures with help from S.-Y. X. S.-Y.X. wrote the article with major help from G.C., D.S.S., and H.L. G.B., H.Z., I.B., and N.A. helped in general with the theoretical analysis and the proof checking of the article. H.L. supervised the theoretical part of the work. M.Z.H. was responsible for the overall direction, planning, and integration among different research units. Competing interests: The authors declare that they have no competing interests. Data and materials availability: All data needed to evaluate the conclusions in the paper are present in the paper and/or the Supplementary Materials. Additional data related to this paper may be requested from the authors.
View Abstract
|
{"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": 0.8503043055534363, "perplexity": 791.9850765972233}, "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/1526794864544.25/warc/CC-MAIN-20180521200606-20180521220606-00527.warc.gz"}
|
https://cs.stackexchange.com/questions/30205/are-there-more-partially-recursive-functions-than-and-recursive-functions
|
# Are there more partially recursive functions than and recursive functions?
Is the cardinality of the set of partially recursive functions greater than the cardinality of the set of recursive functions ?
No they have the same cardinality. They have the cardinality $\aleph_0$. Both sets are infinite in size so we have to compare them based on their level of infiniteness, since as we know there are infinite levels of infinity. Both sets are countably infinite so we say they have the same cardinality.
• Maybe a better way is to observe that they are both represented by finite strings. The set of all finite strings is countable. Both classes are at most countable. Seeing also that for any natural number $c$, you have the constant function $f_c:x \mapsto c$, gives that both sets are infinite. Hence both classes are infinite and countable. – Pål GD Sep 22 '14 at 20:41
|
{"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": 0.9056337475776672, "perplexity": 165.13283142715977}, "config": {"markdown_headings": true, "markdown_code": false, "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-2020-24/segments/1590348523564.99/warc/CC-MAIN-20200607044626-20200607074626-00578.warc.gz"}
|
https://oeis.org/wiki/Complete_sequences
|
This site is supported by donations to The OEIS Foundation.
# Complete sequences
Please do not rely on any information it contains.
A sequence of natural numbers is complete when all positive integers can be represented as the sum of some finite subsequence of the sequence.[1] A sequence is weakly complete (often simply complete in recent literature) when all sufficiently large numbers can be so represented. If the sum of finite subsequences contains some infinite arithmetic progression the sequence is called subcomplete. The same terminology is used for sets and multisets.
## Definition
Given a sequence S of positive integers, let P(S) be the set of numbers which can be represented as the sum of a finite subsequence of S. Then S is complete if (and only if)
${\displaystyle P(S)=\mathbb {N} ,}$
weakly complete if (and only if)
${\displaystyle \mathbb {N} \setminus P(S)}$
is finite, and subcomplete if and only if there are positive integers m and n such that
${\displaystyle \{mk+n:k\in \mathbb {N} \}\subset P(S).}$
A necessary and sufficient condition for a sequence of positive integers to be complete is that the smallest term is 1 and the sum of the smallest n terms is greater than the n+1-st term.[2] Hence the sequence of the powers of 2 is a term-by-term upper bound on any complete sequence.
## Relationship between complete and subcomplete
For every subcomplete set, the addition of finitely many elements can transform it into a complete set. (The same holds trivially for subcomplete sequences and multisets.) The reverse is also true: removing any finite number of elements from a complete sequence yields a subcomplete sequence.
A subcomplete sequence S is weakly complete if and only if for all n, P(S) has an element in all residue classes mod n.
## Density
Paul Erdős conjectured that ${\displaystyle \scriptstyle a(n+1)/a(n)\to 1}$ was sufficient for a set to be subcomplete, but Cassels[3] showed that even ${\displaystyle \scriptstyle a(n+1)/a(n)<1+a_{n}^{-1/2+\varepsilon }}$ is not sufficient for subcompleteness.
Erdős[4] then proved a minimal density, which was improved by Folkman[5] Hegyvári[6], Łuczak & Schoen[7], and finally Szemerédi & Vu[8] who showed that (with ${\displaystyle \scriptstyle A(x)=\left|\{s\in S:s\leq x\}\right|}$) there is a constant c such that if
${\displaystyle A(n)>c{\sqrt {n}}}$
for all n then S is subcomplete. There are sequences with
${\displaystyle A(n)>{\sqrt {2n}}}$
which are not subcomplete, so the result is the best possible up to the constant.
The analogous result for multisets and sequences was proved by Folkman[5] and improved by Szemerédi & Vu[9] who show that that (with ${\displaystyle \scriptstyle A^{*}(x)}$ being the number of elements of S up to x, with multiplicity) there is a constant c such that if
${\displaystyle A^{*}(n)>cn}$
for all sufficiently large n then S is subcomplete.
## Polynomials
Roth & Szekeres[10] showed that if a polynomial with real coefficients maps integers to integers, a necessary and sufficient condition for the range of the polynomial p to be weakly complete is that the leading coefficient is positive and for any prime p there is an integer m such that p does not divide f(m).
Graham[11] re-proves the theorem by a different technique and gives an alternate necessary and sufficient criterion. Write ${\displaystyle \scriptstyle f(x)=c_{0}+c_{1}{x \choose 1}+\cdots +c_{n}{x \choose n},}$ then ${\displaystyle \scriptstyle f(\mathbb {N} )}$ is weakly complete if and only if ${\displaystyle \scriptstyle c_{n}>0}$ and ${\displaystyle \scriptstyle \operatorname {gcd} (N(c_{i}))=1}$ where N finds the numerator in lowest terms (or gives 0 if the number is irrational).
Alternately, if a (rational) polynomial maps positive integers to positive integers, its image is subcomplete. Burr[12] extends this theorem to perturbed polynomials: if f is a polynomial of positive degree, ${\displaystyle \scriptstyle \alpha <1,}$ and ${\displaystyle \scriptstyle s_{n}=f(n)+O(n^{\alpha })}$ is a sequence of positive integers, then ${\displaystyle \scriptstyle \{a_{1},a_{2},\ldots \}}$ is subcomplete. He also proves a version allowing noninteger exponents in the 'polynomial'.
## References
1. V. E. Hoggatt and Charles King, Problem for Solution: E1424, The American Mathematical Monthly 67:6 (Jun.-Jul. 1960), p. 593.
2. J. L. Brown, Jr., Note on complete sequences of integers, The American Mathematical Monthly 68:6 (Jun.-Jul. 1961), pp. 557-560.
3. J. W. S. Cassels, On the representation of integers as sums of distinct summands taken from a fixed set, Acta Scientiarum Mathematicarum (Szeged) 21 (1960), pp. 111–124.
4. Paul Erdős, On the representation of large integers as sums of distinct summands taken from a fixed set, Acta Arithmetica 7:4 (1962), pp. 345-354.
5. J. Folkman, On the representation of integers as sums of distinct terms from a fixed sequence, Canad. J. Math. 18 (1966), pp. 643–655.
6. Norbert Hegyvári, On the representation of integers as sums of distinct terms from a fixed set, Acta Arithmetica 92:2 (2000), pp. 99-104.
7. Tomasz Łuczak and Tomasz Schoen, On the maximal density of sum-free sets, Acta Arithmetica 95:3 (2000), pp. 225-229.
8. E. Szemerédi and V. H. Vu, Finite and infinite arithmetic progressions in sumsets, Annals of of Mathematics (2) 163:1 (2006), pp. 1-35]
9. E. Szemerédi and V. Vu, Long arithmetic progressions in sumsets: thresholds and bounds, J. Amer. Math. Soc. 19:1 (2006), pp. 119–169. See also the preprint arXiv:math/0507539 though this does not contain the result in question.
10. K. R. Roth and G. Szekeres, Some asymptotic formulae in the theory of partitions, Quarterly J. Math. 5 (1954), pp. 241-259.
11. R. L. Graham, Complete sequences of polynomial values, Duke Math. J. 31 (1964), pp. 275-285.
12. Stefan A. Burr, On the completeness of sequences of perturbed polynomial values, Pacific J. Math. 85:2 (1979), pp. 355-360.
|
{"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 17, "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": 0.8888489603996277, "perplexity": 509.6433993934892}, "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/1614178363072.47/warc/CC-MAIN-20210301212939-20210302002939-00610.warc.gz"}
|
https://www.physicsforums.com/threads/help-with-complex-frequency.612982/
|
Help with Complex Frequency
1. Jun 10, 2012
Markel
Help with "Complex Frequency"
Hello all,
I need some help with this concept. I don't really see how a frequency can be complex. I am using a vector network analyzer over a range of a few GHz, however the model I'm using requires as a complex frequency as input. How do I convert an angular frequency to complex frequency?
By searching other posts, I found that complex frequency s = σ + jω, where σ is related to the decay rate. But how do I find this decay rate from a machine which is simply operating X Hz?
Thanks,
2. Jun 10, 2012
Bob S
Re: Help with "Complex Frequency"
Are you really looking at a vector frequency like F(ωt) = Fo [cos(ωt) + j·sin(ωt)]?
3. Jun 11, 2012
Markel
Re: Help with "Complex Frequency"
I'm not entirely sure what you mean, but I don't think so.
I simply have a model for the dielectric properties of a test material, and the model is explicit in s, the complex frequency. However I've only measured some reflection coeficients at specific frequencies, and I have until now only ever heard of real frequencies.
4. Jun 11, 2012
Andy Resnick
Re: Help with "Complex Frequency"
I've seen complex frequencies used when computing thermal properties of materials (specifically, the Hamaker constant).
5. Jun 11, 2012
DragonPetter
Re: Help with "Complex Frequency"
Complex frequency may be misleading because it includes more information than just frequency. You have to consider it in the context of sinusoidal waves with a certain phase in time. Complex frequency is not a different or special kind of "imaginary frequency", the only frequency that is physical is real-number frequency; the phase and magnitude information is affected by this complex component. The s-plane includes magnitude and phase information in addition to frequency information, and complex numbers are a good way of representing the inter-relation of all these quantities. It is just given this name "complex" because complex numbers are how we represent the same values, magnitude - phase - frequency, in the frequency and time domain (see Euler's ... identity/formula I can't remember which is which).
Last edited: Jun 11, 2012
6. Jun 11, 2012
Markel
Re: Help with "Complex Frequency"
Ok, that makes sense.
So how do I construct the complex frequency from real frequency? Is there something like a fourier transform?
7. Jun 11, 2012
DragonPetter
Re: Help with "Complex Frequency"
You should think of complex frequency as the s-plane or another complex domain. In fact, I don't really ever recall using the term complex frequency as a specific term during my studies, but I am not an expert. It seems very confusing to attach to that term. Let me be more specific, you will not find complex "imaginary frequency" information in the frequency domain that never shows up or hides itself from the time domain information that you experience as physically real.
Are you familiar with phasors? http://en.wikipedia.org/wiki/Phasor That should help you to get to the bottom of your problem. Can you express a phasor as a complex number, and then encode the phase,magnitude, and frequency of your signal into complex form? My guess is that your network analyzer wants to know all of this information rather than just frequency.
There is a guy on here called rbj that probably can give you an accurate and better answer, so maybe you should ask this in the EE forum.
Last edited: Jun 11, 2012
8. Jun 11, 2012
Markel
Re: Help with "Complex Frequency"
Thanks for the help. At least now I know what to look for. So the article on S plane in wikipedia gives the following laplace transform:
${F(s) = \int_0^{inf} f(t)e^{-st}dt}$
So if I have a constant frequency with time, I should get as F(s):
${F(s) = \int_0^{inf} \omega e^{-st}dt} = \frac{\omega}{s}$
But now what is s?
9. Jun 11, 2012
rbj
Re: Help with "Complex Frequency"
actually, i never thought that the problem new electrical engineers (and students) usually are having was with "complex frequency", but was with "complex signals" and with "negative frequency".
i guess the concept of complex frequency might have some meaning in the context of exponentially damped (or increasing, in an unstable system) sinusoids. i guess you could say that this signal:
$$x(t) = e^{-\alpha t} \cos( \omega t )$$
has a complex frequency where $\omega$ might be considered to be the real part and $\alpha$ is the imaginary part.
is this what you're having trouble with?
10. Jun 11, 2012
DragonPetter
Re: Help with "Complex Frequency"
I think you have confused the laplace transform. f(t) is a function of time, and so w is just a constant in your attempt. You just transformed a DC signal (with amplitude of w). This will not give you the complex representation of a sine with a frequency w.
Look at this, and find sin(wt) and cos(wt).
http://www.stanford.edu/~boyd/ee102/laplace-table.pdf
11. Jun 11, 2012
the_emi_guy
Re: Help with "Complex Frequency"
Markel,
Can you provide the VNA model that you are using, and the specific setup item that you are trying to input. As mentioned above, you may be confusing complex frequency with complex frequency response. If you can show us exactly what you are trying to do we can help you sort it out.
12. Jun 12, 2012
Markel
Re: Help with "Complex Frequency"
Here is the VNA I'm using:
http://www2.rohde-schwarz.com/product/zvt8.html
And I'm trying to get the dielectric permitivities in relation to Y, the aperture admitance from this model.
$Y = \frac{\sum_{n=1}^{4} \sum_{p=1}^{8}\hat{\alpha}(\sqrt{\epsilon_{r}})^{p}(sa)^{n}}{1+\sum_{m=1}^{4} \sum_{q=1}^{8}\hat{\beta}(\sqrt{\epsilon_{r}})^{q}(sa)^{m}}$
Where $\ s = \sigma + i\omega$ the complex frequency $\ a$ is the conductor radius, $\hat{\alpha}$ and $\hat{\beta}$ are modeling parameters.
Thanks for the help.
13. Jun 12, 2012
AlephZero
Re: Help with "Complex Frequency"
I would back off a bit from your "real" problem and start by figuring out how to get the admittance parameters for a simple RCL circult from your VNA.
You need some sort of curve fitting process, to convert the measured "amplitude and phase response against frequency" into "poles, zeros and residuals" and thus turn the measurements into into an admittance function like Y(s) = s / (Ls^2 + Rs + 1/C).
Just browing some of the analyser guides, it's not too clear whether the VNA has the software to do that built in, or you need some other signal processing software (e.g. simething supplied with the analyser that runs on a PC).
The admittance function in your model is a ratio of low order polynomials, so it is of this general form, but it representing a network with several "resonant circuts", not just one.
I don't think you want to start researching how to do the curve fitting yourself, especially if you are starting from the level of "what is a complex frequency" - you shoudn't need to understand all the details of how the software works to use it.
Note, I'm more familiar with this in measuring mechanical vibrations, but the basic math is the same so the steps in the process must be similar.
14. Jun 14, 2012
the_emi_guy
Re: Help with "Complex Frequency"
Markel,
Sounds like you are measuring the permittivity of some substance using the open ended coaxial probe method. Is this correct?
15. Jun 16, 2012
Markel
Re: Help with "Complex Frequency"
Yes, that's right. Here's the paper where I found the model I mentioned above. My measurements are not giving physical results, and I think the problem may be how I used the frequency.
16. Jul 24, 2012
Markel
Re: Help with "Complex Frequency"
So the transform according to what you sent is:
$\sin{\omega t} \implies \frac{s}{s^{2} + \omega ^2} = \frac{1/2}{s - jw} + \frac{1/2}{s + jw}$
But I'm not really sure if the frequency generated by the VNA is a sine wave. Does someone know how to check this.
Also, I'm still confused as to what 's' is. Being that it's in the exponent of the e^{-st} it appears to be the inverse of some time constant of decay. Where do I find a value for s? If my signal is of constant amplitude, can I assume that s = 0 ?
17. Jul 24, 2012
Markel
Re: Help with "Complex Frequency"
Do you have much experience with this method? If so, I'd really love to pick your brain for a bit.
|
{"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": 0.8216036558151245, "perplexity": 970.6448435030048}, "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-2018-17/segments/1524125947705.94/warc/CC-MAIN-20180425061347-20180425081347-00377.warc.gz"}
|
http://www.physicsforums.com/showpost.php?p=2511980&postcount=4
|
View Single Post
P: 17
Changes in planet orbits as a star (eg. the Sun) decreases is mass.
Quote by S.Vasojevic Yes planets are moving their orbits as sun losses mass. But numbers are almost insignificant. When you add both solar winds and mass-energy conversion of sun, I think that you get about one earth's own radius increase in earth's orbit over entire life of sun so far.
Thanks for the answer. Sorry if it sounded like a stupid question, I didn't realise that the change in Orbit would be so insignificant.
|
{"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": 0.8628157377243042, "perplexity": 1493.615845012479}, "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-2014-23/segments/1406510259834.25/warc/CC-MAIN-20140728011739-00142-ip-10-146-231-18.ec2.internal.warc.gz"}
|
https://www.physicsforums.com/threads/closed-set-proof.830944/
|
# Closed set proof
1. Sep 5, 2015
1. The problem statement, all variables and given/known data
Show that the set of limit points of the set $A \subseteq \mathbb{R}$ given by $L$ is a closed set.
2. Relevant theorems
Definition: A closed set F (subset of R) is such that it contains its limit points.
Definition: A limit point x of a set A (subset of R) is such that the intersection Of every epsilon neighborhood with A excluding x is not empty.
Theorem: A number x is a limit point if and only if some cauchy sequence in A is convergent to x while each term in that cauchy sequence is not equal to x.
Theorem: A set F is closed if and only if every cauchy sequence in F has a limit that is also an element of F.
3. The attempt at a solution
Proof: Since $L$ is the set of limit points $A \subseteq \mathbb{R}$, then if $(a_n)$ is a cauchy sequence in $A$ then $\lim a_n \in L$. Suppose $x$ is a limit point of $L$, then we can form a cauchy sequence satisfying $l_n \neq x$ for all $n$, and $\lim l_n = x$. However, each term in the sequence $(l_n)$ is a limit reached by some cauchy sequence in $A$.
I will try to construct a cauchy sequence in A that converges to x hence showin that $x \in L$ and $L$ is a closed set.
We start by choosing $(a_n)$ such that;
$$|a_n - l_n| < \frac{1}{n}$$
For this definition of $(a_n)$, given any $\epsilon > 0$, we choose $\frac{1}{N_1} < \frac{\epsilon}{2}$ such that for all $n \geq N_1$;
$$|a_n - l_n| < \frac{\epsilon}{2}$$
Since $(l_n)$ converges to $x$, then, for all $n \geq N_2$;
$$|l_n - x| < \frac{\epsilon}{2}$$
Choosing $N = \max{(N_1,N_2)}$;
$$|a_n - x| = |(a_n - l_n) - (l_n - x)| \leq |a_n - l_n| + |l_n - x| < \epsilon$$
Hence, this contruction of $(a_n)$ converges to $x$.
Q.E.D.
Is this correct?
Last edited: Sep 5, 2015
2. Sep 5, 2015
### PeroK
I think you have the essense of the proof, but it's not very clear. For example, the first statement in your proof is:
"Since $L$ is the set of limit points $A \subseteq \mathbb{R}$, then if $(a_n)$ is a cauchy sequence in $A$ such that $\lim a_n \in L$."
This doesn't make sense. Also, you would benefit from writing what you are trying to prove. You've left the "relevent equations" section blank, but actually your definition of a limit point and a closed set are relevant here.
And, at the end, you omit stating the significance of $(a_n)$ converging to $x$.
I would take what you have and seriously tidy things up. For example, I would start:
"To show that $L$ is closed, we will show that $L$ contains its limit points. Let $x$ be a limit point of $L$ ..."
3. Sep 5, 2015
My sincerest apologies
"Since $L$ is the set of limit points $A \subseteq \mathbb{R}$, then if $(a_n)$ is a cauchy sequence in $A$ THEN $\lim a_n \in L$."
i will update the relevant theorems sections in a second, and polish some parts of the proof. Thanks for the feedback.
Last edited: Sep 5, 2015
4. Sep 9, 2015
I read that the only way to improve in proof writing is to let someone rip apart the proofs you write. Please, any suggestions regarding this proof are most welcome :)
5. Sep 9, 2015
### andrewkirk
A couple of suggestions, as you requested Ahmad:
This can be expressed more clearly and succinctly as:
A number x is a limit point of a set A if and only if there is a Cauchy sequence in A-{x} whose limit is x.
This can be expressed more clearly and succinctly as:
Suppose $x$ is a limit point of $L$, then we can form a cauchy sequence of points in L-{x} with limit $x$.
6. Sep 9, 2015
Thank you very much for the suggestions!
Also, could u provide insight into the validity of the proof. I am specially concerned about the part where i construct the cauchy sequence, since i feel the construction is very artificial.
7. Sep 9, 2015
### andrewkirk
Are you allowed to use the axiom of choice Ahmad? You have used it at least twice, once in choosing the sequence $(l_k)$ and once in choosing $(a_k)$.
I'm pretty sure the proof can be done without using the axiom of choice, but generally such proofs are longer and require more care than proofs that use it.
Also, the following is not valid without some justification being provided.
A justification is available, but requires a few steps and should not be omitted.
in any case, I suspect there's a better way of putting this, that is easier to justify. But first we need to know whether you're allowed to use Choice.
8. Sep 10, 2015
I am not familiar with the axiom of choice, could you please give me a reference on the axiom of choice.
I had as my goal the proof that L is closed. I assumed that x is arbitrary limit point of L, which allows me to say that there exists a sequence in L-{x} such that it converges to x. This allowed me to say that (ln) exists. Now i wanted to show that there exists a sequence in A such that it converges to x as well, this would imply that x is in L be definition of L. Since i am trying to prove a "there exists" statement i assumed that i had the right to show that a certain construction works.
There is a justification for the choice of (an) which i believe i mentioned in passing. We know that there exists a sequence in A-{ln} that converges to ln, so since there is such sequence for each n, i chose an element from each such sequence that is within 1/n from ln.
There is a much easier proof given in my book, but i self study real analysis and try to guess the reasoning and if possible work it out on my own.
Last edited: Sep 10, 2015
9. Sep 10, 2015
### andrewkirk
The wikipedia article on the axiom of choice is a pretty good start. Basically the axiom asserts that if you have an infinite collection of non-empty sets you can choose a set that has exactly one element from each. Most theorems in topology and analysis can be proved without it. But a surprising number of ordinary-looking theorems do require it. It's generally preferred not to use it if possible because if we accept it then some really weird consequences follow.
My statement that you used it twice was incorrect. You didn't use it when you chose the sequence $(l_k)$, because that is only choosing one sequence from a set of sequences converging on x, which we know to be non-empty because x is a limit point. Hence it's making only one choice. But you used the axiom when you defined the sequence $(a_k)$ because for every $k\in \mathbb{N}$ you are choosing one value of $a_k$ from among the infinite number of possibilities, and an infinite number of such choices has to be made - one for each $k$.
10. Sep 11, 2015
Hmmm my book "understanding analysis" followed the same argument in many occassions so i just assumed that i had the right to use it as well. So i will post-pone my understanding here until i get a good grip on the axiom of choice.
Thank you :)
11. Sep 11, 2015
### andrewkirk
I think that the axiom of choice may be needed to prove it by using a sequence that converges to x, as you've tried to do, because one has to define that sequence, which may require making an infinite number of choices. Hence I don't think sequences are a good way to approach this proof.
I think it would be easier to prove by using your above definition of limit point 'A limit point x of a set A (subset of R) is such that the intersection Of every epsilon neighborhood with A excluding x is not empty.'
If we assume that x, a limit point of L, is not in L, then it's not a limit point of A, so what does the definition of limit point tell us about how 'far away' x must be from A? Can that lead us to a contradiction with the assumption that it's a limit point of L?
12. Sep 11, 2015
### andrewkirk
I know how you feel. My topology book - the venerable 'Topology' by Munkres - explains the Axiom of Choice and why it's important, all very nice and clearly, but then proceeds to freely assume it in all sorts of proofs where it doesn't need to, and without even making it clear when he's doing it*. That annoys the heck out of me because I consider it very important to know whether a theorem requires Choice to prove it, given how contentious the axiom is.
*it's a good exercise to go through a proof and try and work out whether it has been used. I often get that wrong, as I did when I thought that your $(l_n)$ sequence used it.
13. Sep 11, 2015
I browsed through the wiki article to get an essence of the axiom of choice. This particular segment seems to me relevant here:
"In many cases such a selection can be made without invoking the axiom of choice; this is in particular the case if the number of bins is finite, or if a selection rule is available: a distinguishing property that happens to hold for exactly one object in each bin. "
Since i have prescribed a rule for the selection of (an) does that imply that i am not invoking the axiom of choice? Or is it not as simple as wiki makes it seem to be, and i need to do yet more reading to come to a concrete comclusion? Thanks.
14. Sep 11, 2015
### andrewkirk
No, because you have not given a procedure for identifying a unique $a_n$. You've just observed that every $l_n$ has a bunch of sequences that converge to it, and you arbitrarily choose one of those sequences from which to pluck $a_n$. And you have to do that an infinite number of times. I think there's a much quicker root to the proof by not using sequences.
15. Sep 11, 2015
There is a much easier way in my book. I will read about the axiom of choice in depth and then revisit this thread. Thank you :)
16. Sep 11, 2015
### andrewkirk
If you don't use sequences, you don't have to worry about the axiom of choice for this problem. It can be done in three lines.
If $x\notin L$ then $\exists\epsilon>0$ such that $(x-\epsilon,x+\epsilon)\subseteq \sim A$.
But $x$ is a limit point of $L$. Can we find a point in $L$ close enough to $x$ that it must be some minimum distance from any point in $A$? Can we get a contradiction from that point?
17. Sep 12, 2015
### verty
If $L$ is defined by $L = \{x \in \mathbb{R}: \phi(x)\}$, one can prove $\phi(x)$ without needing $(a_n)$ to exist.
1. WLOG, for each $n$ let $s_n$ be an arbitrary sequence of $A$ converging to $l_n$.
2. WLOG, for each $n$ let $a_n$ be an arbitrary element of $s_n$ so assigned, such that $|a_n - l_n| < {\epsilon \over 2}$.
3. The $a_n$'s so assigned are such that $\phi(x)$ is satisfied, but no generality was lost, therefore $\phi(x)$.
I confess to not being an expert at rigour but I personally didn't see a problem with the given sequences proof.
Have something to add?
Draft saved Draft deleted
Similar Discussions: Closed set proof
|
{"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": 0.9701571464538574, "perplexity": 219.61082298722502}, "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-2018-09/segments/1518891812873.22/warc/CC-MAIN-20180220030745-20180220050745-00389.warc.gz"}
|
https://worldwidescience.org/topicpages/d/dynamic+materials+accountability+system.html
|
#### Sample records for dynamic materials accountability system
1. Accounting for system dynamics in reserve design.
Science.gov (United States)
Leroux, Shawn J; Schmiegelow, Fiona K A; Cumming, Steve G; Lessard, Robert B; Nagy, John
2007-10-01
Systematic conservation plans have only recently considered the dynamic nature of ecosystems. Methods have been developed to incorporate climate change, population dynamics, and uncertainty in reserve design, but few studies have examined how to account for natural disturbance. Considering natural disturbance in reserve design may be especially important for the world's remaining intact areas, which still experience active natural disturbance regimes. We developed a spatially explicit, dynamic simulation model, CONSERV, which simulates patch dynamics and fire, and used it to evaluate the efficacy of hypothetical reserve networks in northern Canada. We designed six networks based on conventional reserve design methods, with different conservation targets for woodland caribou habitat, high-quality wetlands, vegetation, water bodies, and relative connectedness. We input the six reserve networks into CONSERV and tracked the ability of each to maintain initial conservation targets through time under an active natural disturbance regime. None of the reserve networks maintained all initial targets, and some over-represented certain features, suggesting that both effectiveness and efficiency of reserve design could be improved through use of spatially explicit dynamic simulation during the planning process. Spatial simulation models of landscape dynamics are commonly used in natural resource management, but we provide the first illustration of their potential use for reserve design. Spatial simulation models could be used iteratively to evaluate competing reserve designs and select targets that have a higher likelihood of being maintained through time. Such models could be combined with dynamic planning techniques to develop a general theory for reserve design in an uncertain world.
2. U.S. national nuclear material control and accounting system
Energy Technology Data Exchange (ETDEWEB)
Taylor, S; Terentiev, V G
1998-12-01
Issues related to nuclear material control and accounting and illegal dealing in these materials were discussed at the April 19--20, 1996 Moscow summit meeting (G7 + Russia). The declaration from this meeting reaffirmed that governments are responsible for the safety of all nuclear materials in their possession and for the effectiveness of the national control and accounting system for these materials. The Russian delegation at this meeting stated that ''the creation of a nuclear materials accounting, control, and physical protection system has become a government priority''. Therefore, in order to create a government nuclear material control and accounting system for the Russian Federation, it is critical to study the structure, operating principles, and regulations supporting the control and accounting of nuclear materials in the national systems of nuclear powers. In particular, Russian specialists have a definite interest in learning about the National Nuclear Material Control and Accounting System of the US, which has been operating successfully as an automated system since 1968.
3. U.S. national nuclear material control and accounting system
Energy Technology Data Exchange (ETDEWEB)
Taylor, S; Terentiev, V G
1998-12-01
Issues related to nuclear material control and accounting and illegal dealing in these materials were discussed at the April 19--20, 1996 Moscow summit meeting (G7 + Russia). The declaration from this meeting reaffirmed that governments are responsible for the safety of all nuclear materials in their possession and for the effectiveness of the national control and accounting system for these materials. The Russian delegation at this meeting stated that ''the creation of a nuclear materials accounting, control, and physical protection system has become a government priority''. Therefore, in order to create a government nuclear material control and accounting system for the Russian Federation, it is critical to study the structure, operating principles, and regulations supporting the control and accounting of nuclear materials in the national systems of nuclear powers. In particular, Russian specialists have a definite interest in learning about the National Nuclear Material Control and Accounting System of the US, which has been operating successfully as an automated system since 1968.
4. A dynamical systems account of sensorimotor contingencies
Directory of Open Access Journals (Sweden)
Thomas eBuhrmann
2013-05-01
Full Text Available According to the sensorimotor approach, perception is a form of embodied know-how, constituted by lawful regularities in the sensorimotor flow or in sensorimotor contingencies (SMCs in an active and situated agent. Despite the attention that this approach has attracted, there have been few attempts to define its core concepts formally. In this paper we examine the idea of SMCs and argue that its use involves notions that need to be distinguished. We introduce four distinct kinds of SMCs, which we define operationally. These are the notions of sensorimotor environment (open-loop motor-induced sensory variations, sensorimotor habitat (closed-loop sensorimotor trajectories, sensorimotor coordination (reliable sensorimotor patterns playing a functional role and sensorimotor strategy (normative organization of sensorimotor coordinations. We make use of a minimal dynamical model of visually-guided categorization to test the explanatory value of the different kinds of SMCs. Finally, we discuss the impact of our definitions on the conceptual development and empirical as well as model-based testing of the claims of the sensorimotor approach.
5. The financial accounting model from a system dynamics' perspective
NARCIS (Netherlands)
Melse, E.
2006-01-01
This paper explores the foundation of the financial accounting model. We examine the properties of the accounting equation as the principal algorithm for the design and the development of a System Dynamics model. Key to the perspective is the foundational requirement that resolves the temporal
6. The financial accounting model from a system dynamics' perspective
NARCIS (Netherlands)
Melse, E.
2006-01-01
This paper explores the foundation of the financial accounting model. We examine the properties of the accounting equation as the principal algorithm for the design and the development of a System Dynamics model. Key to the perspective is the foundational requirement that resolves the temporal confl
7. The financial accounting model from a system dynamics' perspective
NARCIS (Netherlands)
Melse, E.
2006-01-01
This paper explores the foundation of the financial accounting model. We examine the properties of the accounting equation as the principal algorithm for the design and the development of a System Dynamics model. Key to the perspective is the foundational requirement that resolves the temporal confl
8. Protecting Material Control and Accounting Systems from falsification by insiders
Energy Technology Data Exchange (ETDEWEB)
Sacks, I.J.
1986-01-01
Over the past several years, DOE facilities handling special nuclear material have been upgrading their material control and accounting (MCandA) systems to protect against insiders. Most of the systems analyzed were found to be relatively secure, but they did contain some insider vulnerabilities. The process of creating the information flow models used to analyze these systems has provided insight into general design features which can eliminate these vulnerabilities. Two of the major features characterizing secure MCandA systems are data independence and data verification. In this paper, these features are illustrated by means of typical, vulnerable MCandA procedures and by the steps needed to correct those vulnerabilities. Based on their assessment experience, the authors provide design guidance which could eliminate many insider vulnerabilities.
9. Dynamics of systems and change in the accounting paradigm
Directory of Open Access Journals (Sweden)
Jorge Luis Juliao Rossi
2006-07-01
Full Text Available The objective of this document is to demonstrate the potential of the dynamics of systems as a thinking trend which may help in the understanding process and the construction of an accounting paradigm change. This objective is framed inside a wider purpose: to propase interdisciplinary encounters that contribute to the necessary paradigm change. The described problem is studied from the «System Thinking», which is an approach with theoretical framework and representation and simulation tools related to the tapie.
10. 48 CFR 252.242-7004 - Material management and accounting system.
Science.gov (United States)
2010-10-01
..., inventory, accounting, or other systems. (2) Valid time-phased requirements means material that is— (i... accounting system. 252.242-7004 Section 252.242-7004 Federal Acquisition Regulations System DEFENSE... CLAUSES Text of Provisions And Clauses 252.242-7004 Material management and accounting system....
11. Safeguards Accountability Network accountability and materials management
Energy Technology Data Exchange (ETDEWEB)
Carnival, G.J.; Meredith, E.M.
1985-01-01
The Safeguards Accountability Network (SAN) is a computerized on-line accountability system for the safeguards accountability control of nuclear materials inventories at Rocky Flats Plant. SAN is a dedicated accountability system utilizing source documents filled out on the shop floor as its base. The system incorporates double entry accounting and is developed around the Material Balance Area (MBA) concept. MBA custodians enter transaction information from source documents prepared by personnel in the process areas directly into the SAN system. This provides a somewhat near-real time perpetual inventory system which has limited interaction with MBA custodians. MBA custodians are permitted to inquire into the system and status items on inventory. They are also responsible for the accuracy of the accountability information used as input to the system for their MBA. Monthly audits by the Nuclear Materials Control group assure the timeliness and accuracy of SAN accountability information.
12. 78 FR 38739 - Special Nuclear Material Control and Accounting Systems for Nuclear Power Plants
Science.gov (United States)
2013-06-27
... COMMISSION Special Nuclear Material Control and Accounting Systems for Nuclear Power Plants AGENCY: Nuclear... Accounting Systems for Nuclear Power Plants.'' This regulatory guide provides guidance on recordkeeping and... nuclear material control and accounting system requirements for nuclear power plants. This guide applies...
13. 77 FR 28407 - Special Nuclear Material Control and Accounting Systems for Nuclear Power Plants
Science.gov (United States)
2012-05-14
... COMMISSION Special Nuclear Material Control and Accounting Systems for Nuclear Power Plants AGENCY: Nuclear...-5028, Special Nuclear Material Control and Accounting Systems for Nuclear Power Plants.'' In DG-5028... Control and Accounting Systems for Nuclear Power Plants.'' DATES: Submit comments by July 16, 2012...
14. Environmental Management Accounting for Cleaner Production: Systematization of Material Flow Cost Accounting (MCFA) into Corporate Management System
OpenAIRE
NAKAJIMA, Michiyasu
2011-01-01
The purpose of this research is to consider the structure of a management system which supports countermeasures for the environment in the manufacturing process by Environmental Management Accounting and particularly by Material Flow Cost Accounting (MFCA) and the features of its management system.
15. Structural properties of the material control and accounting system
Energy Technology Data Exchange (ETDEWEB)
1978-12-01
A unified digraph approach is proposed for the assessment of the structure of the MC and A System. The approach emphasizes the two structural aspects of the system: vulnerability and reliability. Vulnerability is defined as a possibility of loosing connectedness in a given structure due to line and/or node removals. It is purely deterministic notion which leads to a qualitative analysis of redundancy of connections in the corresponding system. Reliability of the MC and A System structure provides a more quantitative way of assessing how safe the system is to random failures of the links representing lines of communication, material paths, monitors, and the components of the power supply network. By assigning probabilities to the lines and nodes of the corresponding digraph, the least reliable path can be used as a measure of the goodness of the system, which can be computed by efficient shortest path algorithms. Both vulnerability and reliability considerations are important in determining the effect of tampering of an adversary with the elements of the MC and M System.
16. An information system for sustainable materials management with material flow accounting and waste input–output analysis
Directory of Open Access Journals (Sweden)
Pi-Cheng Chen
2017-05-01
Full Text Available Sustainable materials management focuses on the dynamics of materials in economic and environmental activities to optimize material use efficiency and reduce environmental impact. A preliminary web-based information system is thus developed to analyze the issues of resource consumption and waste generation, enabling countries to manage resources and wastes from a life cycle perspective. This pioneering system features a four-layer framework that integrates information on physical flows and economic activities with material flow accounting and waste input–output table analysis. Within this framework, several applications were developed for different waste and resource management stakeholders. The hierarchical and interactive dashboards allow convenient overview of economy-wide material accounts, waste streams, and secondary resource circulation. Furthermore, the system can trace material flows through associated production supply chain and consumption activities. Integrated with economic models; this system can predict the possible overloading on the current waste management facility capacities and provide decision support for designing strategies to approach resource sustainability. The limitations of current system are specified for directing further enhancement of functionalities.
17. Safeguards Accountability Network accountability and materials management
Energy Technology Data Exchange (ETDEWEB)
Carnival, G.J.; Meredith, E.M.
1985-01-01
The Safeguards Accountability Network (SAN) is an on-line accountability system used by Rocky Flats Plant to provide accountability control of its nuclear material inventory. The system is also used to monitor and evaluate the use of the nuclear material inventory against programmatic objectives for materials management. The SAN system utilizes two Harris 800 Computers as central processing units. Enhancement plans are currently being formulated to provide automated data collection from process operations on the shop floor and from non-destructive analysis safeguards instrumentation. SAN, discussed in this paper, is an excellent system for basic accountability control of nuclear materials inventories and is a quite useful tool in evaluating the efficient use of nuclear materials inventories at Rocky Flats Plant.
18. An enactive and dynamical systems theory account of dyadic relationships
Directory of Open Access Journals (Sweden)
Miriam eKyselo
2014-05-01
Full Text Available Many social relationships are a locus of struggle and suffering, either at the individual or interactional level. In this paper we explore why this is the case and suggest a modeling approach for dyadic interactions and the well-being of the participants. To this end we bring together an enactive approach to self with dynamical systems theory. Our basic assumption is that the quality of any social interaction or relationship fundamentally depends on the nature and constitution of the individuals engaged in these interactions. From an enactive perspective the self is conceived as an embodied and socially enacted autonomous system striving to maintain an identity. This striving is involves a basic two-fold goal: the ability to exist as an individual in its own right, while also being open to and affected by others. In terms of dynamical systems theory one can thus consider the individual self as a self-other organized system represented by a phase space spanned by the dimensions of distinction and participation, and in which attractors can be defined. Based on two everyday examples of dyadic relationship we propose a simple model of relationship dynamics in which struggle or well-being in the dyad is analyzed in terms of movements of dyadic states that are in tension or in harmony with individually developed attractors. Our model predicts that relationships can be sustained when the dyad develops a new joint attractor towards which dyadic states tend to move, and well-being when this attractor is in balance with the individuals’ attractors. We outline how this can inspire research on psychotherapy. The psychotherapy process itself provides a setting in which participants can become aware how they fare with regards to the two-fold norm of distinction and participation and develop, through active engagement between client (or couple and therapist, strategies to co-negotiate their self-organization.
19. Nonequilibrium dynamics in chemical systems A brief account
Science.gov (United States)
Nicolis, G.; Baras, F.
1985-12-01
During the period of September 3 to 7, 1984 a symposium on “Nonequilibrium Dynamics in Chemical Systems” was organized by the Centre de Recherche Paul Pascal in Bordeaux, France. It was supported, primarily, by the French Centre National de la Recherche Scientifique and attended by about 90 participants from Australia, Belgium, Canada, Denmark, France, Germany, Hungary, Israël, Italy, Japan, The Netherlands, Poland, Tchekoslovakia, Spain, United Kingdom, United States and Zimbabwe. A list of topics and speakers is found in the table below. Two highly successful conferences centered on nonlinear phenomena in chemical systems far from equilibrium had already been organized by the Bordeaux group in the past. The first of them [1], held in September 1978, was dominated by the theme that nonequilibrium can act as a source of order. Sustained oscillations and bistability were the two principal phenomena studied from this point of view. Thanks to the systematic utilization of the continuous stirred tank reactor (CSTR) the study of open systems could finally be realized. Reliable state diagrams were thus produced, notably by the Bordeaux group, in which one could identify the transition points to new states. The Belousov-Zhabotinskii (BZ) reaction and its variants were the main vehicle on which these new ideas could be illustrated. The second Bordeaux conference [2], held in September 1981, was largely dominated by the major progress that had just marked two vital areas of this field: the discovery of new classes of chemical oscillators; and the invasion of chaotic dynamics in chemistry. These themes also dominated the first Gordon Conference on Chemical Oscillations held in New Hampshire in July 1982. In contrast to its two predecessors, the third Bordeaux conference held in September 1984 was not dominated by a single central theme. New questions were raised in situations in which until very recently things were considered to be perfectly clear. Simple,
20. The Status of Development on a Web-Based Nuclear Material Accounting System at KAERI
Energy Technology Data Exchange (ETDEWEB)
Lee, Byungdoo; Kim, Inchul; Lee, Seungho; Kim, Hyunjo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)
2014-05-15
The Integrated Safeguards (IS) has been applied to 10 nuclear facilities and 1 location outside facility (LOF) at the Korea Atomic Energy Research Institute (KAERI) since July 2008. One of the major changes in the implementation of safeguards under the IS is to apply the concept of a Random Interim Inspection (RII) instead of an interim inspection. The RII plan is notified within a few hours under the IS. It is thus difficult for facility operators to prepare the inspection documents within a short time if they do not periodically manage and process the nuclear material accounting data at each facility. To resolve these issues, KAERI developed a Web-based accounting system with the function of a near real-time accounting (NRTA) system to effectively and efficiently manage the nuclear material accounting data produced at the nuclear facilities and cope with a short notice inspection under the IS, called KASIS (KAeri Safeguards Information treatment System). The facility operators must input the accounting data on the inventory changes, which are the transfers of nuclear materials among the nuclear facilities and the chemical/physical composition changes, into the KASIS. KAERI also established an RFID system for controlling and managing the transfer of nuclear material and/or radioactive materials between the nuclear facilities for the purpose of nuclear safety management, and developed the nuclear material accounting system with the functions of inventory management of nuclear material at the facility level.
1. The first stage of BFS integrated system for nuclear materials control and accounting. Final report
Energy Technology Data Exchange (ETDEWEB)
NONE
1996-09-01
The BFS computerized accounting system is a network-based one. It runs in a client/server mode. The equipment used in the system includes a computer network consisting of: One server computer system, including peripheral hardware and three client computer systems. The server is located near the control room of the BFS-2 facility outside of the stone sack to ensure access during operation of the critical assemblies. Two of the client computer systems are located near the assembly tables of the BFS-1 and BFS-2 facilities while the third one being the Fissile Material Storage. This final report details the following topics: Computerized nuclear material accounting methods; The portal monitoring system; Test and evaluation of item control technology; Test and evaluation of radiation based nuclear material measurement equipment; and The integrated demonstration of nuclear material control and accounting methods.
2. Study on interface between nuclear material accounting system and national nuclear forensic library
Energy Technology Data Exchange (ETDEWEB)
Jeong, Yonhong; Han, Jae-Jun; Chang, Sunyoung; Shim, Hye-Won; Ahn, Seungho [Korea Institute of Nuclear Non-proliferation and Control, Daejeon (Korea, Republic of)
2016-10-15
The implementation of nuclear forensics requires physical, chemical and radiological characteristics with transport history to unravel properties of seized nuclear materials. For timely assessment provided in the ITWG guideline, development of national response system (e.g., national nuclear forensic library) is strongly recommended. Nuclear material accounting is essential to obtain basic data in the nuclear forensic implementation phase from the perspective of nuclear non-proliferation related to the IAEA Safeguards and nuclear security. In this study, the nuclear material accounting reports were chosen due to its well-established procedure, and reviewed how to efficiently utilize the existing material accounting system to the nuclear forensic implementation phase In conclusion, limits and improvements in implementing the nuclear forensics were discussed. This study reviewed how to utilize the existing material accounting system for implementing nuclear forensics. Concerning item counting facility, nuclear material properties can be obtained based on nuclear material accounting information. Nuclear fuel assembly data being reported for the IAEA Safeguards can be utilized as unique identifier within the back-end fuel cycle. Depending upon the compulsory accountability report period, there exist time gaps. If national capabilities ensure that history information within the front-end nuclear fuel cycle is traceable particularly for the bulk handling facility, the entire cycle of national nuclear fuel would be managed in the framework of developing a national nuclear forensic library.
3. Dynamic modelling of packaging material flow systems.
Science.gov (United States)
Tsiliyannis, Christos A
2005-04-01
A dynamic model has been developed for reused and recycled packaging material flows. It allows a rigorous description of the flows and stocks during the transition to new targets imposed by legislation, product demand variations or even by variations in consumer discard behaviour. Given the annual reuse and recycle frequency and packaging lifetime, the model determines all packaging flows (e.g., consumption and reuse) and variables through which environmental policy is formulated, such as recycling, waste and reuse rates and it identifies the minimum number of variables to be surveyed for complete packaging flow monitoring. Simulation of the transition to the new flow conditions is given for flows of packaging materials in Greece, based on 1995--1998 field inventory and statistical data.
4. Framework for the systematic assessment of a material control and accounting system
Energy Technology Data Exchange (ETDEWEB)
Schechter, R.S.; Sacks, I.J.
1981-04-22
Procedures are described for the systematic assessment of a Material Control and Accounting (MC and A) system, in terms of compliance to the proposed MC and A Upgrade Rule. The applicability of these assessment procedures to specific Rule provisions is discussed. Special attention is given to the statistical performance of individual subsystems, and their vulnerability to compromise by insider collusion.
5. Second Language Developmental Dynamics: How Dynamic Systems Theory Accounts for Issues in Second Language Learning
Science.gov (United States)
Rosmawati
2014-01-01
Dynamic systems theory (DST) is presented in this article as a suitable approach to research the acquisition of second language (L2) because of its close alignment with the process of second language learning. Through a process of identifying and comparing the characteristics of a dynamic system with the process of L2 learning, this article…
6. Upgrade of the Nuclear Material Protection, Control and Accounting System at the VNIIEF Industrial Zone
Energy Technology Data Exchange (ETDEWEB)
Lewis, J.C.; Maltsev, V.; Singh, S.P.
1999-09-20
The Industrial Zone at the Russian Federal Nuclear Center/All-Russian Scientific Research Institute of Experimental Physics (RFNC/VNEEF) consists of ten guarded areas with twenty two material balance areas (A and As). The type of facilities in the Industrial Zone include storage sites, machine shops, research facilities, and training facilities. Modernization of the Material Protection, Control and Accounting (MPC and A) System at the Industrial Zone started in 1997. This paper provides a description of, the methodology/strategy used in the upgrade of the MFC and A system.
7. Advanced international training course on state systems of accounting for and control of nuclear materials
Energy Technology Data Exchange (ETDEWEB)
1981-10-01
This report incorporates all lectures and presentations at the Advanced International Training Course on State Systems of Accounting for and Control of Nuclear Material held April 27 through May 12, 1981 at Santa Fe and Los Alamos, New Mexico, and Richland, Washington, USA. Authorized by the US Nuclear Non-Proliferation Act and sponsored by the US Department of Energy in cooperation with the International Atomic Energy Agency, the course was developed to provide practical training in the design, implementation, and operation of a state system of nuclear materials accountability and control that satisfies both national and international safeguards. Major emphasis for the 1981 course was placed on safeguards methods used at bulk-handling facilities, particularly low-enriched uranium conversion and fuel fabrication plants. The course was conducted by the University of California's Los Alamos National Laboratory, the Battelle Pacific Northwest Laboratory, and Exxon Nuclear Company, Inc. Tours and demonstrations were arranged at both the Los Alamos National Laboratory, Los Alamos, New Mexico, and the Exxon Nuclear fuel fabrication plant, Richland, Washington.
8. New automated inventory/material accounting system (AIMAS) version for former Soviet Union countries
Energy Technology Data Exchange (ETDEWEB)
Kuzminski, Jozef [Los Alamos National Laboratory; Ewing, Tom [ANL; Sakunov, Igor [AVIS CORP., KIEV, UKRAINE; Drapey, Sergey [GEORGE KUZMYCZ TRAINING; Nations, Jim [GREGG PROTECTION SERVICES
2009-01-01
AIMAS (Automated Inventory/Material Accounting System) is a PC-based application for site-level nuclear material accountancy that was originally developed in the late 90's as a part of the U.S Department of Energy Assistance Program to Ukraine. Designed to be flexible and secure, plus place minimal demands on computing infrastructure, it was originally developed to run in early Windows operating system (OS) environments like W98 and W3.1. The development, support, and maintenance of AIMAS were transferred to Ukraine in 2002. Because it is highly flexible and can be configured to meet diverse end-user's needs, the software has been used at several facilities in Ukraine. Incorporating added functionality is planned to support nuclear installations in the Republic of Kazakhstan and Uzbekistan, as well. An improved 32-bit version of AIMAS has recently been developed to operate effectively on modern PCs running the latest Windows OS by AVIS, the Ukrainian developer. In the paper we discuss the status of AIMAS, plans for new functions, and describe the strategy for addressing a sustainable software life-cycle while meeting user requirements in multiple FSU countries.
9. A Continuous Automated Vault Inventory System (CAVIS) for accountability monitoring of stored nuclear materials
Energy Technology Data Exchange (ETDEWEB)
Pickett, C.A.; Barham, M.A.; Gafford, T.A.; Hutchinson, D.P.; Jordan, J.K.; Maxey, L.C.; Moran, B.W.; Muhs, J.; Nodine, R.; Simpson, M.L. [and others
1994-12-08
Nearly all facilities that store hazardous (radioactive or non-radioactive) materials must comply with prevailing federal, state, and local laws. These laws usually have components that require periodic physical inspections to insure that all materials remain safely and securely stored. The inspections are generally labor intensive, slow, put personnel at risk, and only find anomalies after they have occurred. The system described in this paper was developed for monitoring stored nuclear materials resulting from weapons dismantlement, but its applications extend to any storage facility that meets the above criteria. The traditional special nuclear material (SNM) accountability programs, that are currently used within most of the Department of Energy (DOE) complex, require the physical entry of highly trained personnel into SNM storage vaults. This imposes the need for additional security measures, which typically mandate that extra security personnel be present while SNM inventories are performed. These requirements increase labor costs and put additional personnel at risk to radiation exposure. In some cases, individuals have received radiation exposure equivalent to the annual maximum during just one inventory verification. With increasing overhead costs, the current system is rapidly becoming too expensive to operate, the need for an automated method of inventory verification is evident. The Continuous Automated Vault Inventory System (CAVIS) described in this paper was designed and prototyped as a low cost, highly reliable, and user friendly system that is capable of providing, real-time weight, gamma. and neutron energy confirmation from each item stored in a SNM vault. This paper describes the sensor technologies, the CAVIS prototype system (built at Y- 12 for highly enriched uranium storage), the technical requirements that must be achieved to assure successful implementation, and descriptions of sensor technologies needed for a plutonium facility.
10. Shearographic System for Dynamic Analysis of Materials under Heat Stress
Directory of Open Access Journals (Sweden)
Nelson A. Correa-Rojas
2013-11-01
Full Text Available Shearography is a tool for monitoring and inspecting of structural flaws and imperfections in different types of industrial, automotive and aeronautics applications. It is based on digital correlation of two speckle patterns in two states of interest: with and without load. The technique has the special quality of being very robust against environmental disturbances. We present a shearographic system to analyze the dynamic behavior of the strain that suffers a material in response to changes in temperature throughout the thermal load process.
11. Design methodology for flexible energy conversion systems accounting for dynamic performance
DEFF Research Database (Denmark)
Pierobon, Leonardo; Casati, Emiliano; Casella, Francesco
2014-01-01
This article presents a methodology to help in the definition of the optimal design of power generation systems. The innovative element is the integration of requirements on dynamic performance into the system design procedure. Operational flexibility is an increasingly important specification...... of these simulations are used within the framework of a multi-objective optimization procedure to identify a number of equally optimal system configurations. A dynamic model of each of these systems is automatically parameterized, by inheriting its parameters values from the design model. Dynamic simulations allow...
12. Enhancing the Learning Achievements and Attitudes of Taiwan Vocational School Students in Accounting with the Dynamic Assessment System
Science.gov (United States)
Shih, Ju-Ling; Ku, David Tawei; Hung, Su-Huan
2013-01-01
We investigate how the computerized dynamic assessment system improves the learning achievements of vocational high school students studying accounting. Our experiment was conducted under the one-group pretest-posttest design of 34 junior students. The questionnaire results were analyzed to determine student-learning attitudes and reactions toward…
13. Enhancing the Learning Achievements and Attitudes of Taiwan Vocational School Students in Accounting with the Dynamic Assessment System
Science.gov (United States)
Shih, Ju-Ling; Ku, David Tawei; Hung, Su-Huan
2013-01-01
We investigate how the computerized dynamic assessment system improves the learning achievements of vocational high school students studying accounting. Our experiment was conducted under the one-group pretest-posttest design of 34 junior students. The questionnaire results were analyzed to determine student-learning attitudes and reactions toward…
14. A Dynamic System to Manage Changes in Course Material
Science.gov (United States)
Zaneldin, Essam K.
2011-01-01
Purpose: Despite the popularity of existing course management systems, they do not consider the management of course material changes, particularly courses that require more than one instructor. The main purpose of this study is to instantly communicate course material changes to all instructors teaching the same course and to communicate approved…
15. Human Resource Accounting System
Science.gov (United States)
Cerullo, Michael J.
1974-01-01
Main objectives of human resource accounting systems are to satisfy the informational demands made by investors and by operating managers. The paper's main concern is with the internal uses of a human asset system. (Author)
16. International training course on implementation of state systems of accounting for and control of nuclear materials: proceedings
Energy Technology Data Exchange (ETDEWEB)
1984-06-01
This report incorporates all lectures and presentations at the International Training Course on Implementation of State Systems of Accounting for and Control of Nuclear Materials held October 17 through November 4, 1983, at Santa Fe and Los Alamos, New Mexico and Richland, Washington, USA. Authorized by the US Nuclear Non-Proliferation Act and sponsored by the US Department of Energy in cooperation with the International Atomic Energy Agency, the course was developed to provide practical training in the design, implementation, and operation of a State system of nuclear materials accountability and control that satisfies both national and international safeguards requirements. Major emphasis for the 1983 course was placed on safeguards methods used at bulk-handling facilities, particularly low-enriched uranium conversion and fuel fabrication plants. The course was conducted by the University of California's Los Alamos National Laboratory and Exxon Nuclear Company, Inc. Tours and demonstrations were arranged at the Los Alamos National Laboratory, Los Alamos, New Mexico, and the Exxon Nuclear fuel fabrication plant, the Battelle Pacific Northwest Laboratory, Westinghouse Fast Flux Test Facility Visitor Center, and Washington Public Power System nuclear reactor facilities in Richland, Washington. Individual presentations were indexed for inclusion in the Energy Data Base.
17. Library Labor Cost Accounting System.
Science.gov (United States)
Du Bois, Dan
The Library Labor Cost Accounting System will provide visibility on current costs of manually processing library materials, at each campus as well as system-wide. The scope of the study includes the following: (1) 100 individual activities, grouped into 14 functional areas, e.g., Ordering, Receiving; and into 3 major operations: Acquisitions,…
18. International training course on implementation of state systems of accounting for and control of nuclear materials: proceedings
Energy Technology Data Exchange (ETDEWEB)
1986-06-01
This report incorporates all lectures and presentations at the International Training Course on Implementation of State Systems of Accounting for and Control of Nuclear Materials held June 3 through June 21, 1985, at Santa Fe and Los Alamos, New Mexico, and San Clemente, California. Authorized by the US Nuclear Non-Proliferation Act and sponsored by the US Department of Energy in cooperation with the International Atomic Energy Agency, the Course was developed to provide practical training in the design, implementation, and operation of a state system of nuclear materials accountability and control that satisfies both national and international safeguards requirements. Major emphasis for the 1985 course was placed on safeguards methods used at item-control facilities, particularly nuclear power generating stations and test reactors. An introduction to safeguards methods used at bulk handling facilities, particularly low-enriched uranium conversion and fuel fabrication plants, was also included. The course was conducted by the University of California's Los Alamos National Laboratory and the Southern California Edison Company. Tours and demonstrations were arranged at the Los Alamos National Laboratory, Los Alamos, New Mexico, and the San Onofre Nuclear Generating Station, San Clemente, California.
19. Statistical estimation of the performance of a fast-neutron multiplicity system for nuclear material accountancy
Energy Technology Data Exchange (ETDEWEB)
Chichester, David L., E-mail: [email protected] [Idaho National Laboratory, 2525 N. Fremont Avenue, Idaho Falls, ID 83415 (United States); Thompson, Scott J.; Kinlaw, Mathew T.; Johnson, James T. [Idaho National Laboratory, 2525 N. Fremont Avenue, Idaho Falls, ID 83415 (United States); Dolan, Jennifer L.; Flaska, Marek; Pozzi, Sara A. [Department of Nuclear Engineering & Radiological Sciences, University of Michigan, 2355 Bonisteel Boulevard, Ann Arbor, MI 48109-2104 (United States)
2015-06-01
Statistical analyses have been performed to develop bounding estimates of the expected performance of a conceptual fast-neutron multiplicity system (FNMS) for assaying plutonium. The conceptual FNMS design includes 32 cubic liquid scintillator detectors, measuring 7.62 cm per side, configured into 4 stacked rings of 8 detectors each. Expected response characteristics for the individual FNMS detectors, as well as the response characteristics of the entire FNMS, were determined using Monte Carlo simulations based on prior validation experiments. The results from these simulations were then used to estimate the Pu assay capabilities of the FNMS in terms of counting time, assay mass, and assay mass variance, using assay mass variance as a figure of merit. The analysis results are compared against a commonly used thermal-neutron coincidence counter. The advantages of using a fast-neutron counting system versus a thermal-neutron counting system are significant. Most notably, the time required to perform an assay to an equivalent assay mass variance is greatly reduced with a fast-neutron system, by more than an order of magnitude compared with that of the thermal-neutron system, due to the reduced probability of random summing with the fast system. The improved FNMS performance is especially relevant for assays involving Pu masses of 10 g or more.
20. Verification Account Management System (VAMS)
Data.gov (United States)
Social Security Administration — The Verification Account Management System (VAMS) is the centralized location for maintaining SSA's verification and data exchange accounts. VAMS account management...
1. Simulation of the dynamic response of radioactive material shipping package-railcar systems during coupling operations
Energy Technology Data Exchange (ETDEWEB)
Fields, S.R.
1983-10-01
The basic equations of the computer model CARDS (Cask-Railcar Dynamic Simulator), developed for the US Nuclear Regulatory Commission to simulate the dynamic behavior of radioactive material shipping package - railcar systems, are presented. A companion model, CARRS (Cask Railcar Response Spectrum Generator), that generates system response as frequency response spectra is also presented in terms of its basic equations. 1 reference, 18 figures.
2. Simulation of the dynamic response of radioactive material shipping package - railcar systems during coupling operations
Energy Technology Data Exchange (ETDEWEB)
Fields, S.R.
1981-12-01
The basic equations of the computer model CARDS (Cask-Railcar Dynamic Simulator), developed for the U.S. Nuclear Regulatory Commission to simulate the dynamic behavior of radioactive material shipping package - railcar systems, are presented. A companion model, CARRS (Casks Railcar Response Spectrum Generator), that generates system response as frequency response spectra is also presented in terms of its basic equations.
3. Tritium accountancy in fusion systems
Energy Technology Data Exchange (ETDEWEB)
Klein, J.E.; Clark, E.A.; Harvel, C.D.; Farmer, D.A.; Tovo, L.L.; Poore, A.S. [Savannah River National Laboratory, Aiken, SC (United States); Moore, M.L. [Savannah River Nuclear Solutions, Aiken, SC (United States)
2015-03-15
The US Department of Energy (DOE) has clearly defined requirements for nuclear material control and accountability (MCA) of tritium whereas the International Atomic Energy Agency (IAEA) does not since tritium is not a fissile material. MCA requirements are expected for tritium fusion machines and will be dictated by the host country or regulatory body where the machine is operated. Material Balance Areas (MBA) are defined to aid in the tracking and reporting of nuclear material movements and inventories. Material sub-accounts (MSA) are established along with key measurement points (KMP) to further subdivide a MBA to localize and minimize uncertainties in the inventory difference (ID) calculations for tritium accountancy. Fusion systems try to minimize tritium inventory which may require continuous movement of material through the MSA. The ability of making meaningful measurements of these material transfers is described in terms of establishing the MSA structure to perform and reconcile ID calculations. For fusion machines, changes to the traditional ID equation will be discussed which includes breeding, burn-up, and retention of tritium in the fusion device. The concept of 'net' tritium quantities consumed or lost in fusion devices is described in terms of inventory taking strategies and how it is used to track the accumulation of tritium in components or fusion machines. (authors)
4. Automated attendance accounting system
Science.gov (United States)
Chapman, C. P. (Inventor)
1973-01-01
An automated accounting system useful for applying data to a computer from any or all of a multiplicity of data terminals is disclosed. The system essentially includes a preselected number of data terminals which are each adapted to convert data words of decimal form to another form, i.e., binary, usable with the computer. Each data terminal may take the form of a keyboard unit having a number of depressable buttons or switches corresponding to selected data digits and/or function digits. A bank of data buffers, one of which is associated with each data terminal, is provided as a temporary storage. Data from the terminals is applied to the data buffers on a digit by digit basis for transfer via a multiplexer to the computer.
5. Dynamical systems
CERN Document Server
Sternberg, Shlomo
2010-01-01
Celebrated mathematician Shlomo Sternberg, a pioneer in the field of dynamical systems, created this modern one-semester introduction to the subject for his classes at Harvard University. Its wide-ranging treatment covers one-dimensional dynamics, differential equations, random walks, iterated function systems, symbolic dynamics, and Markov chains. Supplementary materials offer a variety of online components, including PowerPoint lecture slides for professors and MATLAB exercises.""Even though there are many dynamical systems books on the market, this book is bound to become a classic. The the
6. TRITIUM ACCOUNTANCY IN FUSION SYSTEMS
Energy Technology Data Exchange (ETDEWEB)
Klein, J. E.; Farmer, D. A.; Moore, M. L.; Tovo, L. L.; Poore, A. S.; Clark, E. A.; Harvel, C. D.
2014-03-06
The US Department of Energy (DOE) has clearly defined requirements for nuclear material control and accountability (MC&A) of tritium whereas the International Atomic Energy Agency (IAEA) does not since tritium is not a fissile material. MC&A requirements are expected for tritium fusion machines and will be dictated by the host country or regulatory body where the machine is operated. Material Balance Areas (MBAs) are defined to aid in the tracking and reporting of nuclear material movements and inventories. Material subaccounts (MSAs) are established along with key measurement points (KMPs) to further subdivide a MBA to localize and minimize uncertainties in the inventory difference (ID) calculations for tritium accountancy. Fusion systems try to minimize tritium inventory which may require continuous movement of material through the MSAs. The ability of making meaningful measurements of these material transfers is described in terms of establishing the MSA structure to perform and reconcile ID calculations. For fusion machines, changes to the traditional ID equation will be discussed which includes breading, burn-up, and retention of tritium in the fusion device. The concept of “net” tritium quantities consumed or lost in fusion devices is described in terms of inventory taking strategies and how it is used to track the accumulation of tritium in components or fusion machines.
7. Modeling habitat dynamics accounting for possible misclassification
Science.gov (United States)
Veran, Sophie; Kleiner, Kevin J.; Choquet, Remi; Collazo, Jaime; Nichols, James D.
2012-01-01
Land cover data are widely used in ecology as land cover change is a major component of changes affecting ecological systems. Landscape change estimates are characterized by classification errors. Researchers have used error matrices to adjust estimates of areal extent, but estimation of land cover change is more difficult and more challenging, with error in classification being confused with change. We modeled land cover dynamics for a discrete set of habitat states. The approach accounts for state uncertainty to produce unbiased estimates of habitat transition probabilities using ground information to inform error rates. We consider the case when true and observed habitat states are available for the same geographic unit (pixel) and when true and observed states are obtained at one level of resolution, but transition probabilities estimated at a different level of resolution (aggregations of pixels). Simulation results showed a strong bias when estimating transition probabilities if misclassification was not accounted for. Scaling-up does not necessarily decrease the bias and can even increase it. Analyses of land cover data in the Southeast region of the USA showed that land change patterns appeared distorted if misclassification was not accounted for: rate of habitat turnover was artificially increased and habitat composition appeared more homogeneous. Not properly accounting for land cover misclassification can produce misleading inferences about habitat state and dynamics and also misleading predictions about species distributions based on habitat. Our models that explicitly account for state uncertainty should be useful in obtaining more accurate inferences about change from data that include errors.
8. ACCRUAL ACCOUNTING BETWEEN DYNAMISM AND PRUDENCE
Directory of Open Access Journals (Sweden)
Mihaela TULVINSCHI
2016-08-01
Full Text Available Economic environment and the behavior of the economic entity is in continuous transformation. A determined value today may be outdated tomorrow. Consequently, maintaining a balance in the activity of the economic entity requires corrective actions. The purpose of this article is to highlight the connection between the accrual accounting, the dynamic accounting theory and the accounting prudence. Establishing the optimal timing for recognition of expenses, revenues and outcome, dynamic accounting theory gives managers quality information in order to make the best decisions. Adopting a prudent behavior is necessary in a reasonable measure in order to avoid serious repercussions caused by an exaggerated optimism.
9. Order Fulfillment and Accounting System
Data.gov (United States)
National Archives and Records Administration — OFAS is the financial management system that tracks and provides accounting of customer service requests for reproductions of National Archives and Records...
10. User's Satisfaction of Multiple Accounting Record System.
Science.gov (United States)
Chen, M C; Yu, H C
2016-01-01
The study hospital had developed a multiple account recording system that generates the accounting information of the consumed materials based on daily nursing records. A questionnaire survey was delivered to further investigate the impact of the system. Four concepts of the system were investigated. (1) Supportive and time saving; (2) impact on workflows and job satisfactions; (3) ease of use; and (4) overall satisfactions. The system scored 4.03 out of 5 as the highest for helpfulness for daily practices, 3.98 for decrease the time for recording material consumptions, 3.98 for actually changed the way they work. Users mostly expressed positive attitude towards the system.
11. Material Systems
DEFF Research Database (Denmark)
Jensen, Mads Brath; Mortensen, Henrik Rubæk; Mullins, Michael;
2009-01-01
This paper describes and reflects upon the results of an investigative project which explores the setting up of a material system - a parametric and generative assembly consisting of and taking into consideration material properties, manufacturing constraints and geometric behavior. The project...... approaches the subject through the construction of a logic-driven system aiming to explore the possibilities of a material system that fulfills spatial, structural and performative requirements concurrently and how these are negotiated in situations where they might be conflicting....
12. Material Systems
DEFF Research Database (Denmark)
Jensen, Mads Brath; Mortensen, Henrik Rubæk; Mullins, Michael
2009-01-01
This paper describes and reflects upon the results of an investigative project which explores the setting up of a material system - a parametric and generative assembly consisting of and taking into consideration material properties, manufacturing constraints and geometric behavior. The project...... approaches the subject through the construction of a logic-driven system aiming to explore the possibilities of a material system that fulfills spatial, structural and performative requirements concurrently and how these are negotiated in situations where they might be conflicting....
13. International training course on nuclear materials accountability for safeguards purposes
Energy Technology Data Exchange (ETDEWEB)
1980-12-01
The two volumes of this report incorporate all lectures and presentations at the International Training Course on Nuclear Materials Accountability and Control for Safeguards Purposes, held May 27-June 6, 1980, at the Bishop's Lodge near Santa Fe, New Mexico. The course, authorized by the US Nuclear Non-Proliferation Act and sponsored by the US Department of Energy in cooperation with the International Atomic Energy Agency, was developed to provide practical training in the design, implementation, and operation of a National system of nuclear materials accountability and control that satisfies both National and IAEA International safeguards objectives. Volume I, covering the first week of the course, presents the background, requirements, and general features of material accounting and control in modern safeguard systems. Volume II, covering the second week of the course, provides more detailed information on measurement methods and instruments, practical experience at power reactor and research reactor facilities, and examples of operating state systems of accountability and control.
14. Implementing New Methods of Laser Marking of Items in the Nuclear Material Control and Accountability System at SSC RF-IPPE: An Automated Laser Marking System
Energy Technology Data Exchange (ETDEWEB)
Regoushevsky, V I; Tambovtsev, S D; Dvukhsherstnov, V G; Efimenko, V F; Ilyantsev, A I; Russ III, G P
2009-05-18
For over ten years SSC RF-IPPE, together with the US DOE National Laboratories, has been working on implementing automated control and accountability methods for nuclear materials and other items. Initial efforts to use adhesive bar codes or ones printed (painted) onto metal revealed that these methods were inconvenient and lacked durability under operational conditions. For NM disk applications in critical stands, there is the additional requirement that labels not affect the neutron characteristics of the critical assembly. This is particularly true for the many stainless-steel clad disks containing highly enriched uranium (HEU) and plutonium that are used at SSC RF-IPPE for modeling nuclear power reactors. In search of an alternate method for labeling these disks, we tested several technological options, including laser marking and two-dimensional codes. As a result, the method of laser coloring was chosen in combination with Data Matrix ECC200 symbology. To implement laser marking procedures for the HEU disks and meet all the nuclear material (NM) handling standards and rules, IPPE staff, with U.S. technical and financial support, implemented an automated laser marking system; there are also specially developed procedures for NM movements during laser marking. For the laser marking station, a Zenith 10F system by Telesis Technologies (10 watt Ytterbium Fiber Laser and Merlin software) is used. The presentation includes a flowchart for the automated system and a list of specially developed procedures with comments. Among other things, approaches are discussed for human-factor considerations. To date, markings have been applied to numerous steel-clad HEU disks, and the work continues. In the future this method is expected to be applied to other MC&A items.
15. The Dynamics of Terms in Accounting
DEFF Research Database (Denmark)
Fuertes-Olivera, Pedro A.; Nielsen, Sandro
2011-01-01
European accounting terminology is dynamic as term creation and formation occurs on national, European Union and international levels. Although English is the lingua franca of accounting, international accounting standards in English exist on a par with their translations into other languages....... However, an analysis of online dictionaries shows that these cannot cope with the dynamic nature of accounting terminology. We discuss a network of internet dictionaries in English, Danish, and Spanish that was compiled using the functional approach to specialised lexicography. We show how terminologists...... can work in subject fields where culture and context play a key role in the development of nationally accepted and internationally recommended terms, and propose ways to remedy deficiencies identified in the dictionaries examined. Finally, we discuss strategies for translating English metaphorical...
16. 议电力物资公司内部会计系统控制%Discussion on Internal Accounting Control System of Power Material Company
Institute of Scientific and Technical Information of China (English)
房萍
2012-01-01
以电力物资公司为例,在分析公司内部会计控制现状的基础上,从建立健全内部会计控制制度、建立全面预算管理制度体系、改进企业货币资金管理、加强应收款项控制、建立全方位成本控制体系、加强固定资产管理控制等几个方面提出完善电力物资公司内部会计控制的措施。%Taking the power material company as an example,based on the analysis of the current situation of internal accounting control of the company,the measures to improve the internal accounting control of the power material company are proposed,from establishing and perfecting the internal accounting control system,establishing the comprehensive budget management system,improving the enterprise monetary fund management,strengthening the receivables control,establishing the comprehensive cost control system,and strengthening the fixed asset management control.
17. JSC interactive basic accounting system
Science.gov (United States)
Spitzer, J. F.
1978-01-01
Design concepts for an interactive basic accounting system (IBAS) are considered in terms of selecting the design option which provides the best response at the lowest cost. Modeling the IBAS workload and applying this workload to a U1108 EXEC 8 based system using both a simulation model and the real system is discussed.
18. Cooperation Between the Russia Federation and the United States to Enhance the Existing Nuclear-Material Protection, Control, and Accounting Systems at Mayak Production Association
Energy Technology Data Exchange (ETDEWEB)
Cahalane, P.T.; Ehinger, M.H.; James, L.T.; Jarrett, J.H.; Lundgren, R.A.; Manatt, D.R.; Niederauer, G.F.; Olivos, J.D.; Prishchepov, A.I.; Starodubtsev, G.S.; Suda, S.C.; Tittemore, G.W.; Zatorsky, Y.M.
1999-07-19
The Ministry of the Russian Federation for Atomic Energy (MINATOM) and the US Department of Energy (DOE) are engaged in joint, cooperative efforts to reduce the likelihood of nuclear proliferation by enhancing Material Protection, Control and Accounting (MPC&A) systems in both countries. Mayak Production Association (Mayak) is a major Russian nuclear enterprise within the nuclear complex that is operated by lylINATOM. This paper describes the nature, scope, and status of the joint, cooperative efforts to enhance existing MPC&A systems at Mayak. Current cooperative efforts are focused on enhancements to the existing MPC&A systems at two of the plants operated by Mayak that work with proliferation-sensitive nuclear materials.
19. KrasMAS: Implementation of a nuclear material computerized accounting system at the Mining and Chemical Combine through the Russian/US cooperative MPC and A program
Energy Technology Data Exchange (ETDEWEB)
Dorofeev, K.V.; Zhidkov, V.V. [Mining and Chemical Combine, Zheleznogorsk (Russian Federation); Martinez, B.J.; Perry, R.T.; Scott, S.C. [Los Alamos National Lab., NM (United States)
1998-12-31
The Russian/US Mining and Chemical Combine (Gorno-Kimichesky Kombinat, GKhK, also referred to as Krasnoyarsk-26) Material Protection, Control and Accounting (MPC and A) project was initiated in June 1996. A critical component of the ongoing cooperative MPC and A enhancements at the GKhK is the implementation of a computerized nuclear material control and accountability (MC and A) system. This system must meet the MC and A requirements of the GKhK by integrating the information generated by numerous existing and new MC and A components in place at the GKhK (e.g., scales, bar-code equipment, NDA measurement systems). During the first phase of this effort, the GKhK adapted CoreMAS (developed at Los Alamos National Laboratory) for use in the PuO{sub 2} storage facility. This included formulation of Web-based user interfaces for plant personnel, Russification of the existing user interface, and at the functional level, modification of the CoreMAS stored procedures. The modified system is referred to as KrasMAS and builds upon completed work on CoreMAS. Ongoing efforts include adding GKhK specific report forms and expanding the functionality of the system for implementation at the radiochemical processing and reactor plants of the GKhK. Collaborations with other Russian facilities for appropriate parts of these efforts will be pursued.
20. KrasMAS: Implementation of a nuclear material computerized accounting system at the Mining and Chemical Combine through the Russian/US cooperative MPC and A program
Energy Technology Data Exchange (ETDEWEB)
Dorofeev, K.V.; Zhidkov, V.V. [Mining and Chemical Combine, Zheleznogorsk (Russian Federation); Martinez, B.J.; Perry, R.T.; Scott, S.C. [Los Alamos National Lab., NM (United States)
1998-12-31
The Russian/US Mining and Chemical Combine (Gorno-Kimichesky Kombinat, GKhK, also referred to as Krasnoyarsk-26) Material Protection, Control and Accounting (MPC and A) project was initiated in June 1996. A critical component of the ongoing cooperative MPC and A enhancements at the GKhK is the implementation of a computerized nuclear material control and accountability (MC and A) system. This system must meet the MC and A requirements of the GKhK by integrating the information generated by numerous existing and new MC and A components in place at the GKhK (e.g., scales, bar-code equipment, NDA measurement systems). During the first phase of this effort, the GKhK adapted CoreMAS (developed at Los Alamos National Laboratory) for use in the PuO{sub 2} storage facility. This included formulation of Web-based user interfaces for plant personnel, Russification of the existing user interface, and at the functional level, modification of the CoreMAS stored procedures. The modified system is referred to as KrasMAS and builds upon completed work on CoreMAS. Ongoing efforts include adding GKhK specific report forms and expanding the functionality of the system for implementation at the radiochemical processing and reactor plants of the GKhK. Collaborations with other Russian facilities for appropriate parts of these efforts will be pursued.
1. Dynamics of pre-strained bi-material elastic systems linearized three-dimensional approach
CERN Document Server
Akbarov, Surkay D
2015-01-01
This book deals with dynamics of pre-stressed or pre-strained bi-material elastic systems consisting of stack of pre-stressed layers, stack of pre-stressed layers and pre-stressed half space (or half plane), stack of pre-stressed layers as well as absolute rigid foundation, pre-stressed compound solid and hollow cylinders and pre-stressed sandwich hollow cylinders. The problems considered in the book relate to the dynamics of a moving and oscillating moving load, forced vibration caused by linearly located or point located time-harmonic forces acting to the foregoing systems. Moreover, a considerable part of the book relate to the problems regarding the near surface, torsional and axisymmetric longitudinal waves propagation and dispersion in the noted above bi-material elastic systems. The book carries out the investigations within the framework of the piecewise homogeneous body model with the use of the Three-Dimensional Linearized Theory of Elastic Waves in Initially Stressed Bodies.
2. A nonlinear dynamical system approach for the yielding behaviour of a viscoplastic material.
Science.gov (United States)
Burghelea, Teodor; Moyers-Gonzalez, Miguel; Sainudiin, Raazesh
2017-02-15
A nonlinear dynamical system model that approximates a microscopic Gibbs field model for the yielding of a viscoplastic material subjected to varying external stresses recently reported in R. Sainudiin, M. Moyers-Gonzalez and T. Burghelea, Soft Matter, 2015, 11(27), 5531-5545 is presented. The predictions of the model are in fair agreement with microscopic simulations and are in very good agreement with the micro-structural semi-empirical model reported in A. M. V. Putz and T. I. Burghelea, Rheol. Acta, 2009, 48, 673-689. With only two internal parameters, the nonlinear dynamical system model captures several key features of the solid-fluid transition observed in experiments: the effect of the interactions between microscopic constituents on the yield point, the abruptness of solid-fluid transition and the emergence of a hysteresis of the micro-structural states upon increasing/decreasing external forces. The scaling behaviour of the magnitude of the hysteresis with the degree of the steadiness of the flow is consistent with previous experimental observations. Finally, the practical usefulness of the approach is demonstrated by fitting a rheological data set measured with an elasto-viscoplastic material.
3. Financial Accountant Versus Managerial Accountant in the Hotel Business System
Directory of Open Access Journals (Sweden)
Ivana Zubac
2012-01-01
Full Text Available From the perspective of financial or managerial accountant, subject of interest in this paper is the relationship of financial and managerial accounting in the hotel business. Being necessary functions within the business system of hotel company, their mutual connection as well as their differences are explained. The management of hotel company makes decisions based on accounting information from both parts of accounting. As support to hotel management in decision-making, financial accountant provides financial information about past events, while managerial accountant provides non-financial information oriented toward future. The example above is just one out of many specific tasks, which are performed by accountants of specific part of hotel accounting system. Without their support, the management could not make correct and timely decisions with certainty. The importance of the roles of financial and managerial accountant is reflected through need for a wide knowledge in the field of accounting in specific business conditions of hotel industry.
4. A nonlinear dynamical systems theory perspective on dual-processing accounts of decision-making under uncertainty
NARCIS (Netherlands)
Rooij, M.M.J.W. van; Favela, L.H.
2016-01-01
Dual-processing accounts of reasoning have gained renewed attention in the past decade, particularly in the fields of social judgment, learning, and decision-making under uncertainty. Although the various accounts differ, the common thread is the distinction between two qualitatively different types
5. Excited electronic state decomposition mechanisms and dynamics of nitramine energetic materials and model systems
Science.gov (United States)
Greenfield, Margo
Energetic materials play an important role in aeronautics, the weapon industry, and the propellant industry due to their broad applications as explosives and fuels. RDX (1,3,5-trinitrohexahydro-s-triazine), HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine), and CL-20 (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane) are compounds which contain high energy density. Although RDX and HMX have been studied extensively over the past several decades a complete understanding of their decomposition mechanisms and dynamics is unknown. Time of flight mass spectroscopy (TOFMS) UV photodissociation (ns) experiments of gas phase RDX, HMX, and CL-20 generate the NO molecule as the initial decomposition product. Four different vibronic transitions of the initial decomposition product, the NO molecule, are observed: A2Sigma(upsilon'=0)←X 2pi(upsilon"=0,1,2,3). Simulations of the rovibronic intensities for the A←X transitions demonstrate that NO dissociated from RDX, HMX, and CL-20 is rotationally cold (˜20 K) and vibrationally hot (˜1800 K). Conversely, experiments on the five model systems (nitromethane, dimethylnitramine (DMNA), nitropyrrolidine, nitropiperidine and dinitropiperazine) produce rotationally hot and vibrationally cold spectra. Laser induced fluorescence (LIF) experiments are performed to rule out the possible decomposition product OH, generated along with NO, perhaps from the suggested HONO elimination mechanism. The OH radical is not observed in the fluorescence experiments, indicating the HONO decomposition intermediate is not an important pathway for the excited electronic state decomposition of cyclic nitramines. The NO molecule is also employed to measure the dynamics of the excited state decomposition. A 226 nm, 180 fs light pulse is utilized to photodissociate the gas phase systems. Stable ion states of DMNA and nitropyrrolidine are observed while the energetic materials and remaining model systems present the NO molecule as the only
6. Accounting information system in turkish shipbuilding industry: Special accounting applications
OpenAIRE
DAŞTAN, Abdulkerim; Sercan EROL
2014-01-01
This study is considered in an effort to analyze the accounting information system in Turkish shipbuilding industry enterprises objectively accompanied by the elements of the accounting organization which are the document, the book and the chart of accounts and to demonstrate the accounting activities which are in existence under the present circumstances in Turkey. Shipbuilding industry creates a lot of added value such as the transfer and production of new technologies, employment and forei...
7. Accounting information system in turkish shipbuilding industry: Special accounting applications
OpenAIRE
DAŞTAN, Abdulkerim; Sercan EROL
2011-01-01
This study is considered in an effort to analyze the accounting information system in Turkish shipbuilding industry enterprises objectively accompanied by the elements of the accounting organization which are the document, the book and the chart of accounts and to demonstrate the accounting activities which are in existence under the present circumstances in Turkey. Shipbuilding industry creates a lot of added value such as the transfer and production of new technologies, employment and forei...
8. The Dynamics of Terms in Accounting
DEFF Research Database (Denmark)
Fuertes-Olivera, Pedro A.; Nielsen, Sandro
2011-01-01
can work in subject fields where culture and context play a key role in the development of nationally accepted and internationally recommended terms, and propose ways to remedy deficiencies identified in the dictionaries examined. Finally, we discuss strategies for translating English metaphorical....... However, an analysis of online dictionaries shows that these cannot cope with the dynamic nature of accounting terminology. We discuss a network of internet dictionaries in English, Danish, and Spanish that was compiled using the functional approach to specialised lexicography. We show how terminologists...
9. Methods of Verification, Accountability and Control of Special Nuclear Material
Energy Technology Data Exchange (ETDEWEB)
Stewart, J.E.
1999-05-03
This session demonstrates nondestructive assay (NDA) measurement, surveillance and analysis technology required to protect, control and account (MPC and A) for special nuclear materials (SNM) in sealed containers. These measurements, observations and analyses comprise state-of-the art, strengthened, SNM safeguards systems. Staff member specialists, actively involved in research, development, training and implementation worldwide, will present six NDA verification systems and two software tools for integration and analysis of facility MPC and A data.
10. Music from chaos: nonlinear dynamical systems as generators of musical materials
OpenAIRE
Bidlack, Rick Aaron
1990-01-01
A body of scientific/mathematical theory arising from a description of the behavior of complex dynamical systems is explored in terms of its pertinence to and utility in musical schemes for the generation of melodic lines and textures. Such systems are known to model significant behavioral features of real-world phenomena, including turbulent or chaotic behavior. Many of the features of nonlinear dynamical systems that are intriguing from a mathematical point of view, especially the propertie...
11. Birth of an Abstraction: A Dynamical Systems Account of the Discovery of an Elsewhere Principle in a Category Learning Task
Science.gov (United States)
Tabor, Whitney; Cho, Pyeong W.; Dankowicz, Harry
2013-01-01
Human participants and recurrent ("connectionist") neural networks were both trained on a categorization system abstractly similar to natural language systems involving irregular ("strong") classes and a default class. Both the humans and the networks exhibited staged learning and a generalization pattern reminiscent of the…
12. Accounting provision for corporate management system functioning
OpenAIRE
Пилипенко, Олексій Іванович
2017-01-01
The peculiarities of accounting provision for corporate management system functioning have been considered. The levels and basic problems of accounting organization in corporations have been determined.
13. Self-consistent system of equations for a kinetic description of the low-pressure discharges accounting for the nonlocal and collisionless electron dynamics.
Science.gov (United States)
Kaganovich, Igor D; Polomarov, Oleg
2003-08-01
In low-pressure discharges, where the electron mean free path is larger or comparable with the discharge length, the electron dynamics is essentially nonlocal. Moreover, the electron energy distribution function (EEDF) deviates considerably from a Maxwellian. Therefore, an accurate kinetic description of the low-pressure discharges requires knowledge of the nonlocal conductivity operator and calculation of the non-Maxwellian EEDF. The previous treatments made use of simplifying assumptions: a uniform density profile and a Maxwellian EEDF. In the present study, a self-consistent system of equations for the kinetic description of nonlocal, nonuniform, nearly collisionless plasmas of low-pressure discharges is derived. It consists of the nonlocal conductivity operator and the averaged kinetic equation for calculation of the non-Maxwellian EEDF. The importance of accounting for the nonuniform plasma density profile on both the current density profile and the EEDF is demonstrated.
14. 76 FR 28193 - Amendments to Material Control and Accounting Regulations
Science.gov (United States)
2011-05-16
... COMMISSION 10 CFR Parts 72, 74, and 150 RIN 3150-AI61 Amendments to Material Control and Accounting... proposed rule language concerning the NRC's proposed amendments to the material control and accounting (MC... FNMC is an outdated term, as it does not include accounting,'' and thus does not fully describe...
15. Professional accounting media - accountants handing over control to the system
DEFF Research Database (Denmark)
Baldvinsdottir, Gudrun; Burns, John; Nørreklit, Hanne
2010-01-01
to place substantial trust in the software. The paper relates these changes to trends in contemporary social practices, and reflects in the light of recent events in the financial markets and global economy more generally. Originality/value - This paper contributes by adding more insight to the diffusion...... and the social practice of management accounting; in particular, whether these adverts are producing an image of management accountants who are in control of their management accounting system or who are controlled by it. The paper also discusses whether these adverts reflect changes in broader social practices...
16. Accounting and Accountability for Distributed and Grid Systems
Science.gov (United States)
Thigpen, William; McGinnis, Laura F.; Hacker, Thomas J.
2001-01-01
While the advent of distributed and grid computing systems will open new opportunities for scientific exploration, the reality of such implementations could prove to be a system administrator's nightmare. A lot of effort is being spent on identifying and resolving the obvious problems of security, scheduling, authentication and authorization. Lurking in the background, though, are the largely unaddressed issues of accountability and usage accounting: (1) mapping resource usage to resource users; (2) defining usage economies or methods for resource exchange; (3) describing implementation standards that minimize and compartmentalize the tasks required for a site to participate in a grid.
17. Dynamical Systems Conference
CERN Document Server
Gils, S; Hoveijn, I; Takens, F; Nonlinear Dynamical Systems and Chaos
1996-01-01
Symmetries in dynamical systems, "KAM theory and other perturbation theories", "Infinite dimensional systems", "Time series analysis" and "Numerical continuation and bifurcation analysis" were the main topics of the December 1995 Dynamical Systems Conference held in Groningen in honour of Johann Bernoulli. They now form the core of this work which seeks to present the state of the art in various branches of the theory of dynamical systems. A number of articles have a survey character whereas others deal with recent results in current research. It contains interesting material for all members of the dynamical systems community, ranging from geometric and analytic aspects from a mathematical point of view to applications in various sciences.
18. 5 CFR 10.2 - Accountability systems.
Science.gov (United States)
2010-01-01
... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Accountability systems. 10.2 Section 10.2 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE RULES AGENCY ACCOUNTABILITY SYSTEMS; OPM AUTHORITY TO REVIEW PERSONNEL MANAGEMENT PROGRAMS (RULE X) § 10.2 Accountability systems. The Director...
19. Invitation to dynamical systems
CERN Document Server
Scheinerman, Edward R
2012-01-01
This text is designed for those who wish to study mathematics beyond linear algebra but are unready for abstract material. Rather than a theorem-proof-corollary exposition, it stresses geometry, intuition, and dynamical systems. 1996 edition.
20. System Dynamics
Science.gov (United States)
Morecroft, John
System dynamics is an approach for thinking about and simulating situations and organisations of all kinds and sizes by visualising how the elements fit together, interact and change over time. This chapter, written by John Morecroft, describes modern system dynamics which retains the fundamentals developed in the 1950s by Jay W. Forrester of the MIT Sloan School of Management. It looks at feedback loops and time delays that affect system behaviour in a non-linear way, and illustrates how dynamic behaviour depends upon feedback loop structures. It also recognises improvements as part of the ongoing process of managing a situation in order to achieve goals. Significantly it recognises the importance of context, and practitioner skills. Feedback systems thinking views problems and solutions as being intertwined. The main concepts and tools: feedback structure and behaviour, causal loop diagrams, dynamics, are practically illustrated in a wide variety of contexts from a hot water shower through to a symphony orchestra and the practical application of the approach is described through several real examples of its use for strategic planning and evaluation.
1. Dynamical systems
CERN Document Server
Birkhoff, George D
1927-01-01
His research in dynamics constitutes the middle period of Birkhoff's scientific career, that of maturity and greatest power. -Yearbook of the American Philosophical Society The author's great book€¦is well known to all, and the diverse active modern developments in mathematics which have been inspired by this volume bear the most eloquent testimony to its quality and influence. -Zentralblatt MATH In 1927, G. D. Birkhoff wrote a remarkable treatise on the theory of dynamical systems that would inspire many later mathematicians to do great work. To a large extent, Birkhoff was writing about his o
2. Earth materials and earth dynamics
Energy Technology Data Exchange (ETDEWEB)
Bennett, K; Shankland, T. [and others
2000-11-01
In the project ''Earth Materials and Earth Dynamics'' we linked fundamental and exploratory, experimental, theoretical, and computational research programs to shed light on the current and past states of the dynamic Earth. Our objective was to combine different geological, geochemical, geophysical, and materials science analyses with numerical techniques to illuminate active processes in the Earth. These processes include fluid-rock interactions that form and modify the lithosphere, non-linear wave attenuations in rocks that drive plate tectonics and perturb the earth's surface, dynamic recrystallization of olivine that deforms the upper mantle, development of texture in high-pressure olivine polymorphs that create anisotropic velocity regions in the convecting upper mantle and transition zone, and the intense chemical reactions between the mantle and core. We measured physical properties such as texture and nonlinear elasticity, equation of states at simultaneous pressures and temperatures, magnetic spins and bonding, chemical permeability, and thermal-chemical feedback to better characterize earth materials. We artificially generated seismic waves, numerically modeled fluid flow and transport in rock systems and modified polycrystal plasticity theory to interpret measured physical properties and integrate them into our understanding of the Earth. This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL).
3. User-Oriented Project Accounting System.
Science.gov (United States)
Hess, Larry G.; Alcorn, Lisa S.
1990-01-01
The project accounting system used by the University of Illinois Urbana-Champaign School of Chemical Sciences exchanges financial data with the campus' central accounting system and allows integration of this information with user-entered data to produce an easily read, fully obligated project accounting statement for the budget and period…
4. Innovations in an Accounting Information Systems Course.
Science.gov (United States)
Shaoul, Jean
A new approach to teaching an introductory accounting information systems course is outlined and the potential of this approach for integrating computers into the accounting curriculum at Manchester University (England) is demonstrated. Specifically, the use of a small inventory recording system and database in an accounting information course is…
5. 10 CFR 74.51 - Nuclear material control and accounting for strategic special nuclear material.
Science.gov (United States)
2010-01-01
... 10 Energy 2 2010-01-01 2010-01-01 false Nuclear material control and accounting for strategic special nuclear material. 74.51 Section 74.51 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) MATERIAL CONTROL AND ACCOUNTING OF SPECIAL NUCLEAR MATERIAL Formula Quantities of Strategic Special Nuclear Material § 74.51 Nuclear material control and...
6. Dynamic Logics of Dynamical Systems
CERN Document Server
Platzer, André
2012-01-01
We survey dynamic logics for specifying and verifying properties of dynamical systems, including hybrid systems, distributed hybrid systems, and stochastic hybrid systems. A dynamic logic is a first-order modal logic with a pair of parametrized modal operators for each dynamical system to express necessary or possible properties of their transition behavior. Due to their full basis of first-order modal logic operators, dynamic logics can express a rich variety of system properties, including safety, controllability, reactivity, liveness, and quantified parametrized properties, even about relations between multiple dynamical systems. In this survey, we focus on some of the representatives of the family of differential dynamic logics, which share the ability to express properties of dynamical systems having continuous dynamics described by various forms of differential equations. We explain the dynamical system models, dynamic logics of dynamical systems, their semantics, their axiomatizations, and proof calcul...
7. Development of accounting quality management system
Directory of Open Access Journals (Sweden)
Plakhtii T.F.
2017-08-01
Full Text Available Accounting organization as one of the types of practical activities at the enterprise involves organization of the process of implementation of various kinds of accounting procedures to ensure meeting needs of the users of accounting information. Therefore, to improve its quality an owner should use tools, methods and procedures that enable to improve the quality of implementation of accounting methods and technology. The necessity of using a quality management system for the improvement of accounting organization at the enterprise is substantiated. The system of accounting quality management is developed and grounded in the context of ISO 9001:2015, which includes such processes as the processes of the accounting system, leadership, planning, and evaluation. On the basis of specification and justification of the set of universal requirements (content requirements, formal requirements the model of the environment of demands for high-quality organization of the computerized accounting system that improves the process of preparing high quality financial statements is developed. In order to improve the system of accounting quality management, to justify the main objectives of its further development, namely elimination of unnecessary characteristics of accounting information, the differences between the current level of accounting information quality and its perfect level are considered; the meeting of new needs of users of accounting information that have not been satisfied yet. The ways of leadership demonstration in the system of accounting quality management of accounting subjects at the enterprise are substantiated. The relationship between the current level of accounting information quality and its perfect level is considered. The possible types of measures aimed at improving the system of accounting quality management are identified. The paper grounds the need to include the principle of proper management in the current set of accounting
8. Integrated safeguards & security for material protection, accounting, and control.
Energy Technology Data Exchange (ETDEWEB)
Duran, Felicia Angelica; Cipiti, Benjamin B.
2009-10-01
Traditional safeguards and security design for fuel cycle facilities is done separately and after the facility design is near completion. This can result in higher costs due to retrofits and redundant use of data. Future facilities will incorporate safeguards and security early in the design process and integrate the systems to make better use of plant data and strengthen both systems. The purpose of this project was to evaluate the integration of materials control and accounting (MC&A) measurements with physical security design for a nuclear reprocessing plant. Locations throughout the plant where data overlap occurs or where MC&A data could be a benefit were identified. This mapping is presented along with the methodology for including the additional data in existing probabilistic assessments to evaluate safeguards and security systems designs.
9. POLICE ACCOUNTABILITY SYSTEM IN ENGLAND AND WALES
OpenAIRE
Balcıoğlu, Ercan; Pala, Erkan
2015-01-01
This article provides the reader with a literature review with the aim of finding out about the origin and system of police accountability in England and Wales. It is hoped that the article will help to identify some important conceptual considerations that ought to betaken into account by any professional and responsible police departments seeking to embrace accountability in its policing procedures.This article explores the sensitive issue of police accountability to civilian oversight bodi...
10. 18 CFR 3a.71 - Accountability for classified material.
Science.gov (United States)
2010-04-01
... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Accountability for classified material. 3a.71 Section 3a.71 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES NATIONAL SECURITY INFORMATION Accountability for...
11. Electrochemically-Modulated Separations for Material Accountability Measurements
Energy Technology Data Exchange (ETDEWEB)
Arrigo, Leah M.; Liezers, Martin; Douglas, Matthew; Green, Michael A.; Farmer, Orville T.; Schwantes, Jon M.; Peper, Shane M.; Duckworth, Douglas C.
2010-05-07
The Safeguards community recognizes that an accurate and timely measurement of accountable material mass at the head-end of the facility is critical to a modern materials control and accountability program at fuel reprocessing plants. For material accountancy, it is critical to detect both acute and chronic diversions of nuclear materials. Therefore, both on-line nondestructive (NDA) and destructive analysis (DA) approaches are desirable. Current methods for DA involve grab sampling and laboratory based column extractions that are costly, hazardous, and time consuming. Direct on-line gamma measurements of Pu, while desirable, are not possible due to contributions from other actinide and fission products. A technology for simple, online separation of targeted materials would benefit both DA and NDA measurements.
12. Accounting balance sheet as a system
Directory of Open Access Journals (Sweden)
2016-04-01
Full Text Available The article actualizes the need to study the systematic approach and accountants’ systematical thinking based on the analysis of the systems theory basic provisions, the applicability of the system properties to the "balance sheet" category and to explore the basic tenets of the existing schools of accounting. It is proved that the accounting is a complex socio-technical system; justified that the study of accounting from the perspective of a systematic approach will enable a better understanding of its structure, principles of functioning and the role of an accountant in its practical implementation.
13. Considerations on Accounting Intelligent Systems Importance
Directory of Open Access Journals (Sweden)
2007-01-01
Full Text Available Managers begin to realize the importance of artificial intelligence technologies for their organizations. Knowledge is today seen as the main organizational resource and that is what intelligent systems are about: manipulating knowledge. In this paper we highlight the main reasons that an accountant can bring to his managers to emphasize this idea: intelligent systems are really needful in modern accounting.
14. Dynamical resource nexus assessments: from accounting to sustainability approaches
Science.gov (United States)
Salmoral, Gloria; Yan, Xiaoyu
2017-04-01
Continued economic development and population growth result in increasing pressures on natural resources, from local to international levels, for meeting societal demands on water, energy and food. To date there are a few tools that link models to identify the relationships and to account for flows of water, energy and food. However, these tools in general can offer only a static view often at national level and with annual temporal resolution. Moreover, they can only account flows but cannot consider the required amounts and conditions of the natural capital that supplies and maintains these flows. With the emerging nexus thinking, our research is currently focused on promoting dynamical environmental analyses beyond the conventional silo mentalities. Our study aims to show new advancements in existing tools (e.g., dynamical life cycle assessment) and develop novel environmental indicators relevant for the resource nexus assessment. We aim to provide a step forward when sustainability conditions and resilience thresholds are aligned with flows under production (e.g., food, water and energy), process level under analysis (e.g., local production, transport, manufacturing, final consumption, reuse, disposal) and existing biophysical local conditions. This approach would help to embrace and better characterise the spatiotemporal dynamics, complexity and existing links between and within the natural and societal systems, which are crucial to evaluate and promote more environmentally sustainable economic activities.
15. THE EVOLUTION OF ACCOUNTING INFORMATION SYSTEMS
Directory of Open Access Journals (Sweden)
Andreea C. BENDOVSCHI
2015-04-01
Full Text Available Technological evolution becomes more and more a daily reality for businesses and individuals who use information systems as for supporting their operational activities. This article focuses on the way technological evolution changes the accounting practices, starting from the analysis of the traditional model and trying to determine future trends and arising challenges to face. From data input to consolidation and reporting, accountants’ function and operations are dissected in order to identify to what extent the development of new concepts, such as cloud computing, cloud accounting, real-time accounting or mobile accounting may affect the financial-accounting process, as well as the challenges that arise from the changing environment.
16. International Target Values for Measurement Uncertainties in Nuclear Material Accountancy
Institute of Scientific and Technical Information of China (English)
LIU; Hong-bin; GAO; Qiang
2012-01-01
<正>The IAEA has published a revised version International Target Values (ITVs) 2010 for Measurement Uncertainties in Safeguarding Nuclear Materials in 2010. The report proposes the international target values of measurement uncertainties of the routine measurement methods for the nuclear material accountancy.
17. Technology development for nuclear material measurement and accountability
Energy Technology Data Exchange (ETDEWEB)
Hong, Jong Sook; Lee, Byung Doo; Cha, Hong Ryul; Lee, Yong Duk; Choi, Hyung Nae; Nah, Won Woo; Park, Hoh Joon; Lee, Yung Kil [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)
1994-12-01
The measurement techniques for Pu samples and spent fuel assembly were developed in support of the implementation of national inspection responsibility under the Atomic Energy Act promulgated in 1994 and a computer program was also developed to assess the total nuclear material balance by facility declared records. The results of plutonium isotopic determination by gamma-ray spectrometry with high resolution germanium detector with peak analysis codes (FRAM and MGA codes) were approached to within 1% {approx} 2% of error from chemical analysis values by mass spectrometry. A gamma-ray measurement system for underwater spent nuclear fuels was developed and tested successfully. The falsification of facility and state records can be traced with the help of the developed computer code against declared reports submitted by the concerned state. This activity eventually resulted in finding the discrepancy of accountability records. 18 figs, 20 tabs, 27 refs. (Author).
18. Dynamic fracture of heterogeneous materials
Energy Technology Data Exchange (ETDEWEB)
Stout, M.G.; Liu, C.; Addessio, F.L.; Williams, T.O.; Bennett, J.G.; Haberman, K.S.; Asay, B.W.
1998-12-31
This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The objective of this project was to investigate the fundamental aspects of the process of dynamic fracture propagation in heterogeneous materials. The work focused on three important, but poorly understood, aspects of dynamic fracture for materials with a heterogeneous microstructure. These were: the appropriateness of using a single-parameter asymptotic analysis to describe dynamic crack-tip deformation fields, the temperature rises at the tip and on the flanks of a running crack, and the constitutive modeling of damage initiation and accumulation.
19. ReflectoActive{trademark} Seals for Materials Control and Accountability
Energy Technology Data Exchange (ETDEWEB)
Richardson, G.D.; Younkin, J.R.; Bell, Z.W.
2002-01-01
The ReflectoActive{trademark} Seals system, a continuously monitored fiber optic, active seal technology, provides real-time tamper indication for large arrays of storage containers. The system includes a PC running the RFAS software, an Immediate Detection Unit (IDU), an Optical Time Domain Reflectometer (OTDR), links of fiber optic cable, and the methods and devices used to attach the fiber optic cable to the containers. When a breach on any of the attached fiber optic cable loops occurs, the IDU immediately signals the connected computer to control the operations of an OTDR to seek the breach location. The ReflectoActive{trademark} Seals System can be adapted for various types of container closure designs and implemented in almost any container configuration. This automatic protection of valued assets can significantly decrease the time and money required for surveillance. The RFAS software is the multi-threaded, client-server application that monitors and controls the components of the system. The software administers the security measures such as a two-person rule as well as continuous event logging. Additionally the software's architecture provides a secure method by which local or remote clients monitor the system and perform administrative tasks. These features provide the user with a robust system to meet today's material control and accountability needs. A brief overview of the hardware, and different hardware configurations will be given. The architecture of the system software, and its benefits will then be discussed. Finally, the features to be implemented in future versions of the system will be presented.
20. AKRO/SF: Catch Accounting System (CAS)
Data.gov (United States)
National Oceanic and Atmospheric Administration, Department of Commerce — The Catch Accounting System (CAS) creates total catch estimates for the groundfish fisheries in the Bering Sea/Aleutian Islands and Gulf of Alaska. Each year, quotas...
1. An experimental investigation of the early dynamic impact behaviour of textile armour systems: Decoupling material from system response
Science.gov (United States)
Cepus, Elvis
This work focuses on the early impact response of textile armour systems. A relatively new data acquisition system, the Enhanced Laser Velocity Sensor (ELVS), was refined and used to generate a large database of results for a 5.57 mm diameter, 3 gram, non-deforming projectile impacting single-ply configurations of Ballistic Nylon, two weaves of Kevlar 129, and Zylon (PBO) over a range of velocities from 61 m/s to 248 m/s. In addition, one Kevlar 129 material was tested in configurations of 2, 3, 4, 8 and 16 plies over a range of strike velocities from 90 m/s to 481 m/s. ELVS results consisted of high-resolution timehistories of displacement, velocity and energy for each system tested. The strain wave velocity and ballistic performance of each system was also determined. Results taken from during the impact event were analysed up to just prior to the strain-wave rebounding from the boundary and returning to the impact point---effectively removing boundary influences. Regardless of system type, a constant rate of energy absorption within the pre-rebound timeframe was found to exist, which scales with the strike velocity to approximately the 8/3-power. Well-established single fibre theory was modified and applied to woven materials. It was assumed that three primary energy absorption mechanisms exist; elastic strain, in-plane kinetic and out-of-plane kinetic. This simple model yields the experimentally observed 8/3 exponent and parametrically predicts the difference between the different single-ply material systems, but underpredicts the observed behaviour by a factor of 2 and cannot address the performance reduction with increasing ply count. This combined experimental and analytical work confirms the long-held assumption that single fibre wave physics is applicable to multi-ply woven systems. More significantly, for the first time, it decouples material response from overall system response and provides the experimental tools and methodology required to analyse
2. Analysis and Design: Accounting Information System in Purchasing and Supplying
Directory of Open Access Journals (Sweden)
Noerlina Noerlina
2011-05-01
Full Text Available The purpose of the research are the purchase and material supply process are the main process of the company and it will determine the operational company, so it needs an accounting information system to help them in the planning and taking the best decision. Research methods used are data and information collected which using the analysis and design method. This method needs to support the design of accounting information system in the company. The result are there’s still any weaknesses happened that will hamper the operational company.Index Terms - Analysis and Design, Accounting Information System, Purchasing, Supply.
3. Material control system simulator program reference manual
Energy Technology Data Exchange (ETDEWEB)
Hollstien, R.B.
1978-01-24
A description is presented of a Material Control System Simulator (MCSS) program for determination of material accounting uncertainty and system response to particular adversary action sequences that constitute plausible material diversion attempts. The program is intended for use in situations where randomness, uncertainty, or interaction of adversary actions and material control system components make it difficult to assess safeguards effectiveness against particular material diversion attempts. Although MCSS may be used independently in the design or analysis of material handling and processing systems, it has been tailored toward the determination of material accountability and the response of material control systems to adversary action sequences.
4. Dynamic Pricing for Airline Revenue Management under Passenger Mental Accounting
Directory of Open Access Journals (Sweden)
Yusheng Hu
2015-01-01
Full Text Available Mental accounting is a far-reaching concept, which is often used to explain various kinds of irrational behaviors in human decision making process. This paper investigates dynamic pricing problems for single-flight and multiple flights settings, respectively, where passengers may be affected by mental accounting. We analyze dynamic pricing problems by means of the dynamic programming method and obtain the optimal pricing strategies. Further, we analytically show that the passenger mental accounting depth has a positive effect on the flight’s expected revenue for the single flight and numerically illustrate that the passenger mental accounting depth has a positive effect on the optimal prices for the multiple flights.
5. Dynamic water accounting in heavily committed river basins
Science.gov (United States)
Tilmant, Amaury; Marques, Guilherme
2014-05-01
Many river basins throughout the world are increasingly under pressure as water demands keep rising due to population growth, industrialization, urbanization and rising living standards. In the past, the typical answer to meet those demands focused on the supply-side and involved the construction of hydraulic infrastructures to capture more water from surface water bodies and from aquifers. As river basins were being more and more developed, downstream water users and ecosystems have become increasingly dependant on the management actions taken by upstream users. The increased interconnectedness between water users, aquatic ecosystems and the built environment is further compounded by climate change and its impact on the water cycle. Those pressures mean that it has become increasingly important to measure and account for changes in water fluxes and their corresponding economic value as they progress throughout the river system. Such basin water accounting should provide policy makers with important information regarding the relative contribution of each water user, infrastructure and management decision to the overall economic value of the river basin. This paper presents a dynamic water accounting approach whereby the entire river basin is considered as a value chain with multiple services including production and storage. Water users and reservoirs operators are considered as economic agents who can exchange water with their hydraulic neighbors at a price corresponding to the marginal value of water. Effective water accounting is made possible by keeping track of all water fluxes and their corresponding transactions using the results of a hydro-economic model. The proposed approach is illustrated with the Eastern Nile River basin in Africa.
6. THE NEED FOR MANAGERIAL ACCOUNTING SYSTEMS
Directory of Open Access Journals (Sweden)
Flavius-Andrei GUINEA
2016-12-01
Full Text Available The implementation of a managerial accounting system represents a genuine initiative for implementing change, this involving the need for change, a vision of change and strategy, and last, but not least, innovation stimulation. In the last decades, the implementation of such a system translated into a broader reform, including the management system used. A management control system, once implemented, tends to attract the manifestation of creative accounting phenomena, especially in times of crisis. Taking these into consideration, the article aims to highlight the importance of the implementation of a modern managerial accounting system in the Romanian firms, as well as to analyse the potential consequences of this process, from the author’s point of view.
7. Accounting and Controlling Business Management System
Directory of Open Access Journals (Sweden)
David Mareš
2016-12-01
Full Text Available The author examines an efficient accounting and management system that gives a true picture of an economic reality with a direct link to the consumer to achieve maximum effectiveness of financial planning and the business as a whole. By this, the accounting information system and its role across the entire business is defined and linked to other subsystems of the business information system at the same time. On the basis of inputs and outputs from information accounting system, the author makes conclusions with regard to linking the accounting information system to preferences and social status of the customer, both using Customer Relationship Management or through his consump - tion expenditures in relation to his consumption needs pyramid and preferences. The paper expands the scientific knowledge in broader context, as it does not examine the given factors of business success separately, but rather in its entirety forming a direct link consumer – accounting information system – controlling – financial plan – performance of individual departments – business performance.
8. Accounting for Investement Property Under Romanian Accounting System
National Research Council Canada - National Science Library
Raluca Sava
2015-01-01
.... Internationally their accounting treatment is presented by the IAS 40 Investment property issued in 2000 and being operative for annual periods beginning on or after 1 January 2001 with a number...
9. The dynamics of accounting terms in a globalized environment
DEFF Research Database (Denmark)
Fuertes-Olivera, Pedro A.; Nielsen, Sandro
2014-01-01
European accounting terminology is dynamic as term creation occurs on national, European Union and international levels. English is the lingua franca of accounting, which influences terminologies in other languages, usually through the work of translators, e.g. the translation of existing...... international accounting standards. The combined influence of these forces is discussed in this chapter that explains the existence of a globalized trend towards a kind of cultural uniformity. This manifests itself in many ways, two of which are: the translation of English multiword accounting terms...... into Spanish; and the presence of novel metaphors in Spanish accounting. The data used in the discussion are taken from the accounting dictionaries, a collection of online dictionaries in three languages: Danish, English and Spanish....
10. Reference Materials System: materials policy information system
Energy Technology Data Exchange (ETDEWEB)
Bhagat, N.K.; Hoffman, K.C.
1979-01-01
The social and economic development of a nation is dependent on a reliable supply of materials and energy and on the efficient utilization of these resources. Decision making in industry and the formulation of government policies require a comprehensive information base encompassing the technical, economic, and environmental factors involved in the flow of materials through production processes and the overall economy. The Reference Materials System (RMS) is a network description of the flow of materials from resource extraction through refinement, production, and transportation processes to the utilization, maintenance, and recycling operations. The system has been employed for the assessment of material production technologies and for the evaluation of substitution possibilities. The RMS provides a framework for integrating engineering and economic information into a comprehensive systems framework. The network flow diagram is quantified in terms of the mass flow of all renewable and nonrenewable materials on an annual basis through each step of the system. A variety of data elements including capital and labor requirements may be organized in this framework to provide a Materials Policy Data Base. This process description of the materials system may also be coupled with economic policy models of the input--output or econometric variety to ensure proper analysis of the role of materials in the overall economy.
11. Energy accounting and optimization for mobile systems
Science.gov (United States)
Dong, Mian
Energy accounting determines how much a software process contributes to the total system energy consumption. It is the foundation for evaluating software and has been widely used by operating system based energy management. While various energy accounting policies have been tried, there is no known way to evaluate them directly simply because it is hard to track every hardware use by software in a heterogeneous multi-core system like modern smartphones and tablets. In this thesis, we provide the ground truth for energy accounting based on multi-player game theory and offer the first evaluation of existing energy accounting policies, revealing their important flaws. The proposed ground truth is based on Shapley value, a single value solution to multi-player games of which four axiomatic properties are natural and self-evident to energy accounting. To obtain the Shapley value-based ground truth, one only needs to know if a process is active during the time under question and the system energy consumption during the same time. We further provide a utility optimization formulation of energy management and show, surprisingly, that energy accounting does not matter for existing energy management solutions that control the energy use of a process by giving it an energy budget, or budget based energy management (BEM). We show an optimal energy management (OEM) framework can always outperform BEM. While OEM does not require any form of energy accounting, it is related to Shapley value in that both require the system energy consumption for all possible combination of processes under question. We provide a novel system solution that meet this requirement by acquiring system energy consumption in situ for an OS scheduler period, i.e.,10 ms. We report a prototype implementation of both Shapley value-based energy accounting and OEM based scheduling. Using this prototype and smartphone workload, we experimentally demonstrate how erroneous existing energy accounting policies can
12. Accounting for microbial habitats in modeling soil organic matter dynamics
Science.gov (United States)
Chenu, Claire; Garnier, Patricia; Nunan, Naoise; Pot, Valérie; Raynaud, Xavier; Vieublé, Laure; Otten, Wilfred; Falconer, Ruth; Monga, Olivier
2017-04-01
The extreme heterogeneity of soils constituents, architecture and inhabitants at the microscopic scale is increasingly recognized. Microbial communities exist and are active in a complex 3-D physical framework of mineral and organic particles defining pores of various sizes, more or less inter-connected. This results in a frequent spatial disconnection between soil carbon, energy sources and the decomposer organisms and a variety of microhabitats that are more or less suitable for microbial growth and activity. However, current biogeochemical models account for C dynamics at the macroscale (cm, m) and consider time- and spatially averaged relationships between microbial activity and soil characteristics. Different modelling approaches have intended to account for this microscale heterogeneity, based either on considering aggregates as surrogates for microbial habitats, or pores. Innovative modelling approaches are based on an explicit representation of soil structure at the fine scale, i.e. at µm to mm scales: pore architecture and their saturation with water, localization of organic resources and of microorganisms. Three recent models are presented here, that describe the heterotrophic activity of either bacteria or fungi and are based upon different strategies to represent the complex soil pore system (Mosaic, LBios and µFun). These models allow to hierarchize factors of microbial activity in soil's heterogeneous architecture. Present limits of these approaches and challenges are presented, regarding the extensive information required on soils at the microscale and to up-scale microbial functioning from the pore to the core scale.
13. Characteristics of Company Accounting Information System
Directory of Open Access Journals (Sweden)
Marija Tokić
2011-12-01
Full Text Available Information has always presented an important factor of human activity. As a resource that guided human activity, information was gathered, stored, analysed and distributed in different ways throughout the history. Today, information system is a necessity in the global business system. Globalisation processes have changed the traditional concept of doing business and brought about the need for information management as an integral part of overall company assets and rapid development of information and communication technology. Regardless of the benefits and advantages that may be offered by the systems, companies do business to earn profit. In this sense information systems should be considered as investment. Although investment costs can be determined relatively precisely, benefits offered by the systems are more difficult to measure and they require comprehensive consideration of all aspects of doing business to which the systems refer. Accounting is an information subsystem of the single information system of a company. Its purpose is to provide comprehensive, systematic and permanent presentation of data and information, based on documents that refer to all elements contained in business subsystems and the business system of the company as a whole. Information resulting from accounting and information system is contained in accounting reports, i.e. calculations, estimates and analyses within which it is presented to the management.
14. A High-Energy, Ultrashort-Pulse X-Ray System for the Dynamic Study of Heavy, Dense Materials
Energy Technology Data Exchange (ETDEWEB)
Gibson, David Jeremy [Univ. of California, Davis, CA (United States)
2004-01-01
Thomson-scattering based x-ray radiation sources, in which a laser beam is scattered off a relativistic electron beam resulting in a high-energy x-ray beam, are currently being developed by several groups around the world to enable studies of dynamic material properties which require temporal resolution on the order of tens of femtoseconds to tens of picoseconds. These sources offer pulses that are shorter than available from synchrotrons, more tunable than available from so-called Ka sources, and more penetrating and more directly probing than ultrafast lasers. Furthermore, Thomson-scattering sources can scale directly up to x-ray energies in the few MeV range, providing peak brightnesses far exceeding any other sources in this regime. This dissertation presents the development effort of one such source at Lawrence Livermore National Laboratory, the Picosecond Laser-Electron InterAction for the Dynamic Evaluation of Structures (PLEIADES) project, designed to target energies from 30 keV to 200 keV, with a peak brightness on the order of 1018 photons • s-1 • mm-2 • mrad-2 • 0.01% bandwidth-1. A 10 TW Ti:Sapphire based laser system provides the photons for the interaction, and a 100 MeV accelerator with a 1.6 cell S-Band photoinjector at the front end provides the electron beam. The details of both these systems are presented, as is the initial x-ray production and characterization, validating the theory of Thomson scattering. In addition to the systems used to enable PLEIADES, two alternative systems are discussed. An 8.5 GHz X-Band photoinjector, capable of sustaining higher accelerating gradients and producing lower emittance electron beams in a smaller space than the S-Band gun, is presented, and the initial operation and commissioning of this gun is presented. Also, a hybrid chirped-pulse amplification system is presented as an alternative to the standard regenerative amplifier technology in high
15. THE DEVELOPMENT OF MATERIAL FLOW INFORMATION BASE OF MANAGEMENT AND ACCOUNTING IN THE CONSTRUCTION INDUSTRY
Directory of Open Access Journals (Sweden)
Degaltseva Z. V.
2015-10-01
Full Text Available This article discusses the problems of using indicators of material flow in the financial accounting management accounting system. The authors have created and described the classification of material costs in building units. It allows solving the problems of object of research specifying within a given material flow and inventory control within a given logistics systems. There are different approaches to the valuation of material costs in the article. An important aspect of measures for the integration development of accounting systems is the adoption of uniform valuation of building materials and structures. It is proved that the most rational combination of these types of records achieved by an adapted classification and measurement of building materials and structures to the conditions of formation of the budget for the project volume of construction works and the reflection of the actual volume of work in the financial accounting system. On the basis of the accounting policies and the organizational structure of the object of investigation of "Kubanstroykompleks" we have identified responsibility centers (sites for costs related to the material flow: Department of logistics and packaging and warehousing, which consists of a central and railroad warehouse
16. Tribological Studies of Dynamic Thermal Seal Materials
Science.gov (United States)
DeMange, Jeffrey J.; Taylor, Shawn C.
2016-01-01
Thermal seals are required on high-speed vehicles in many dynamic applications such as variable inlets in propulsion systems and control surfaces. These seals, often referred to as dynamic thermal seals, must not only mitigate inboard heat transfer, but must also exhibit sufficient durability when scrubbed against mating surfaces. For high-temperature high-speed vehicle applications, the mating surfaces are often made from thermal protection system (TPS) materials, which are typically rougher and more abrasive than TPS materials used at lower temperatures. The high-temperature TPS materials used can include non-ablative (e.g., lightweight porous oxides, ceramic matrix composites) andor ablative systems (e.g., phenolic systems). Due to the increased need for durable high-temperature dynamic seals, researchers working with the NASA Glenn Research Center embarked on an effort to (a) characterize the tribological performance of state-of-the-art thermal seal materials against a variety of TPS materials and (b) develop approaches for improved wear resistance. Tests were conducted using a recently upgraded high-temperature tribometer to assess wear resistance for a variety of tribopairs under multiple conditions. This data will begin to frame the challenges of using these materials and eventually permit an improved ability to design and implement these critical TPS components.
17. A national accounting system for worker flows
NARCIS (Netherlands)
Broersma, L; den Butter, FAG; Kock, U
We present a national accounting system for the construction of a consistent macro data set for worker flows. It is an alternative to micro data sets on gross labour flows derived from panels. The method is applied to construct annual flow data for The Netherlands for 1997. (C) 2000 Elsevier Science
18. Robust topology optimization accounting for misplacement of material
DEFF Research Database (Denmark)
Jansen, Miche; Lombaert, Geert; Diehl, Moritz
2013-01-01
into account this type of geometric imperfections. A density filter based approach is followed, and translations of material are obtained by adding a small perturbation to the center of the filter kernel. The spatial variation of the geometric imperfections is modeled by means of a vector valued random field......The use of topology optimization for structural design often leads to slender structures. Slender structures are sensitive to geometric imperfections such as the misplacement or misalignment of material. The present paper therefore proposes a robust approach to topology optimization taking....... The random field is conditioned in order to incorporate supports in the design where no misplacement of material occurs. In the robust optimization problem, the objective function is defined as a weighted sum of the mean value and the standard deviation of the performance of the structure under uncertainty...
19. Display of the information model accounting system
Directory of Open Access Journals (Sweden)
Matija Varga
2011-12-01
Full Text Available This paper presents the accounting information system in public companies, business technology matrix and data flow diagram. The paper describes the purpose and goals of the accounting process, matrix sub-process and data class. Data flow in the accounting process and the so-called general ledger module are described in detail. Activities of the financial statements and determining the financial statements of the companies are mentioned as well. It is stated how the general ledger module should function and what characteristics it must have. Line graphs will depict indicators of the company’s business success, indebtedness and company’s efficiency coefficients based on financial balance reports, and profit and loss report.
20. Dynamic model of production enterprises based on accounting registers and its identification
Science.gov (United States)
Sirazetdinov, R. T.; Samodurov, A. V.; Yenikeev, I. A.; Markov, D. S.
2016-06-01
The report focuses on the mathematical modeling of economic entities based on accounting registers. Developed the dynamic model of financial and economic activity of the enterprise as a system of differential equations. Created algorithms for identification of parameters of the dynamic model. Constructed and identified the model of Russian machine-building enterprises.
1. ACCOUNTING SYSTEMS AND THEIR CONVERGENCES NOWADAYS
Directory of Open Access Journals (Sweden)
DARABOS Eva
2014-07-01
Full Text Available The expansion of opportunities and the disappearance of country borders make the answering the question increasingly urgent that which country’s or region’s acts and customs as precedents the accounting created for measuring the economic performance should use in the future. The fact makes this question especially interesting that these acts and customs often differ from each other significantly even within a region. The objective of the study is to introduce the major accounting systems (US GAAP, EU directives, IFRS and their supporting institutional background in a conception way with a special regard on compiling financial statements on the basis of IFRS. The accounts should include not only validity but the preciseness expected by both the owners and the creditors focusing on consistency, the usefulness, transparency and unambiguousness of the contained pieces of information. All these are especially important when a given enterprise or an enterprise-group represents itself in several countries or continents. The actuality of the topic is strengthened by the fact that more and more entities being interested even in abroad require to use a system based on internationally accepted standards as a basis when compiling annual accounts and consolidation for the sake of comparability.
2. High Speed Dynamics in Brittle Materials
Science.gov (United States)
Hiermaier, Stefan
2015-06-01
3. Temperature pattern dynamics in shocked porous materials
Institute of Scientific and Technical Information of China (English)
2010-01-01
The physical fields in porous materials under strong shock wave reaction are very complicated. We simulate such systems using the grain contact material point method. The complex temperature fields in the material are treated with the morphological characterization. To compare the structures and evolution of characteristic regimes under various temperature thresholds, we introduce two concepts, structure similarity and process similarity. It is found that the temperature pattern dynamics may show high similarity under various conditions. Within the same material, the structures and evolution of high-temperature regimes may show high similarity if the shock strength and temperature threshold are chosen appropriately. For process similarity in materials with high porosity, the required temperature threshold increases parabolically with the impact velocity. When the porosity becomes lower, the increasing rate becomes higher. For process similarity in different materials, the required temperature threshold and the porosity follow a power-law relationship in some range.
4. MATERIAL ACCOUNTING HARMONIZATION: AN OVERVIEW OF TRADE LITERATURE
Directory of Open Access Journals (Sweden)
Dragos Dana Simona
2010-07-01
Full Text Available Our paper develops an overview of trade literature within the particular area of material accounting harmonization. The usefulness of this paper consists in offering an up to date image on what was written on this particular topic with significant practical implications. We first divide existent studies on stages that we consider can be grounded based on trade literature’s evolution. Furthermore, a qualitative analysis is done for studies belonging to each period. Limitations of previous studies are also synthesized. The final point of our analysis gives shape to research perspectives that further needs to be exploited.
5. ACCOUNTING, AN ESSENTIAL COMPONENT OF THE INFORMATION SYSTEM
Directory of Open Access Journals (Sweden)
PALIU -POPA LUCIA
2013-02-01
Full Text Available In the context of deep financial and economic transformations taking place both nationally and globally, theneed and appropriateness of ongoing and increased involvement of accounting information in the management processis increasingly obvious under the increasing credibility and relevance of such information in user perception. Althoughthe data, information and knowledge provided by accounting are not the only ones characterizing a particular economicunit, we believe they are an essential element for analysis and assessment of the entity's statement of assets, motivationaccording to which accounting is seen by the management, and not only, as the core of the information system.Thus, the accounting information experiences a wide revaluation on all the decision-making stages specific toa field of activity, materialized, for this purpose, in economic and financial indicators that are obtained either directlyfrom synthetic and analytical accounts, or through calculations based on them, regularly and periodically, dependingon the need and possibility of operational knowledge of such indicators or only at certain times.Therefore the main purpose of the accounting information system is to provide each user, according to itsresponsibilities and tasks, with all the necessary information, representing both an interface between the operating andthe management system of the entity, but also an element connecting the internal and the external environment of thecompany, a perspective that motivates our scientific approach orientation in the research of accounting informationand its role in the decision making process.
6. FINANCIAL-ACCOUNTING INFORMATION SYSTEMS – RATIO BETWEEN ACCOUNTING ORGANISATION SYSTEM AND INFORMATIC APPROACH
Directory of Open Access Journals (Sweden)
CODREANU DIANA ELENA
2012-05-01
Full Text Available Practical activities have lately started to use complex financial-accounting informatic systems on a large scale, facilitating the establishment of a background for improving informational processes and substantiating decisions, also taking account of the requirements when implementing the mechanism of market-oriented economy.The financial-accounting informatic system in any economic organisation has the role to show the data and outcomes of company economic performance in a format that is beneficial and useful to accountants and managers in order to ensure the good running of their companies. Thus, when information is necessary to substantiate a decision in terms of economic matters, the field of financial-accounting data along with the related informatic system provide the information needed for three management functions: planning, control and evaluation.
7. Dynamical system synchronization
CERN Document Server
Luo, Albert C J
2013-01-01
Dynamical System Synchronization (DSS) meticulously presents for the first time the theory of dynamical systems synchronization based on the local singularity theory of discontinuous dynamical systems. The book details the sufficient and necessary conditions for dynamical systems synchronizations, through extensive mathematical expression. Techniques for engineering implementation of DSS are clearly presented compared with the existing techniques. This book also: Presents novel concepts and methods for dynamical system synchronization Extends beyond the Lyapunov theory for dynamical system synchronization Introduces companion and synchronization of discrete dynamical systems Includes local singularity theory for discontinuous dynamical systems Covers the invariant domains of synchronization Features more than 75 illustrations Dynamical System Synchronization is an ideal book for those interested in better understanding new concepts and methodology for dynamical system synchronization, local singularity...
8. for hybrid dynamical systems
Directory of Open Access Journals (Sweden)
2001-01-01
Full Text Available In this paper we develop a unified dynamical systems framework for a general class of systems possessing left-continuous flows; that is, left-continuous dynamical systems. These systems are shown to generalize virtually all existing notions of dynamical systems and include hybrid, impulsive, and switching dynamical systems as special cases. Furthermore, we generalize dissipativity, passivity, and nonexpansivity theory to left-continuous dynamical systems. Specifically, the classical concepts of system storage functions and supply rates are extended to left-continuous dynamical systems providing a generalized hybrid system energy interpretation in terms of stored energy, dissipated energy over the continuous-time dynamics, and dissipated energy over the resetting events. Finally, the generalized dissipativity notions are used to develop general stability criteria for feedback interconnections of left-continuous dynamical systems. These results generalize the positivity and small gain theorems to the case of left-continuous, hybrid, and impulsive dynamical systems.
9. Regional material flow accounting and environmental pressures: the Spanish case.
Science.gov (United States)
Sastre, Sergio; Carpintero, Óscar; Lomas, Pedro L
2015-02-17
This paper explores potential contributions of regional material flow accounting to the characterization of environmental pressures. With this aim, patterns of material extraction, trade, consumption, and productivity for the Spanish regions were studied within the 1996-2010 period. The main methodological variation as compared to whole-country based approaches is the inclusion of interregional trade, which can be separately assessed from the international exchanges. Each region was additionally profiled regarding its commercial exchanges with the rest of the regions and the rest of the world and the related environmental pressures. Given its magnitude, interregional trade is a significant source of environmental pressure. Most of the exchanges occur across regions and different extractive and trading patterns also arise at this scale. These differences are particularly great for construction minerals, which in Spain represent the largest share of extracted and consumed materials but do not cover long distances, so their impact is visible mainly at the regional level. During the housing bubble, economic growth did not improve material productivity.
10. The value of crop germplasm and value accounting system
Institute of Scientific and Technical Information of China (English)
WANG Xiaowei; DING Guangzhou; CHANG Ying
2007-01-01
The value evaluation and accounting of crop germplasm not only provides the theory and method for the price of germplasm, thus makes further lawful and fair transactions, but also ensures the benefits of crop germplasm owners and is also instructive in keeping the foodstuff safety. This paper founded a multidimensional value accounting system, which included physical accounting, value accounting and quality index accounting; individual accounting and total accounting; quantity accounting and quality accounting.
11. Compare the Chinese and American Accounting Management System
Institute of Scientific and Technical Information of China (English)
刘晨
2014-01-01
Cultureplays an important role in the development of accounting. Dif erent culture environments foster dif erent accountants, andthen dif erent accounting subcultures, which wil have dif erent influence on the choice of accounting systems. Dif erent cultures in China and the United States influenced the two countries accounting system, which lead to dif erent management system.
12. A Study of University Teaching-materials Management Accounts Processing System Based on Credit%基于学分制的高校教材管理账务处理系统的研究
Institute of Scientific and Technical Information of China (English)
曾俊国; 王飞
2012-01-01
Currently, teaching-materials management information system software of most colleges and universities is designed and achieved in accordance with "entering-marketing-storage" mode, and this kind of software is simple and clear. But because of the special nature of university management and social services functions, and the gradual implementation of credit in university, the account management module function can not meet the needs of the current management of university teaching-materials. This article explains that new account management subsystem of teaching-materials management information system adapting to nowadays demand is implemented based on Combination C# and SQL Server in use of C/S and B/S model.%目前,大多数高校的教材管理信息系统软件几乎都是按照“进-销-存”模式来设计和实现的,按这种模式开发的软件条理清晰,结构简单,但由于高校教材管理方式和社会服务职能的特殊性,加之学分制在高等院校的逐步推行,其账务管理功能模块远不能满足目前高校教材管理工作的需要.本文主要阐释在C#+SQL Server环境下,利用C/S和B/S相结合的模式设计适应新形势下的高校教材管理账务处理系统的解决方案.
13. A new method of material resources management based on material flow cost accounting for industrial enterprises
OpenAIRE
Khaldin, K. S.
2016-01-01
In the article a new method of material resources management for industrial enterprises is introduced. The method is based on the concepts of sustainable development and the elements of environmental management theory, such as life cycle assessment and material flow cost accounting. Steps that have to be completed in order to improve material resources efficiency are outlined and discussed in detail. Two possible optimization routines are also introduced and reviewed, namely: search for a bet...
14. A reference material for dynamic displacement calibration
Science.gov (United States)
Davighi, A.; Hack, E.; Patterson, E.; Whelan, M.
2010-06-01
Calibration of displacement and strain measurement systems is an essential step in providing traceability and confidence in stress and strain distributions obtained from experiment and used to validate simulations employed in engineering design. Reference materials provide a simple, well-defined distribution of the measured quantity that can be traced to an international standard and can be used to assess the uncertainty associated with the measurement system. Previous work has established a reference material and procedure for calibrating optical systems for measuring static, in-plane strain distributions and also demonstrated its use. A new effort is in progress to extend this work to the measurement of three-dimensional displacement distributions induced by cyclic and dynamic loading, including transients and large-scale deformation. The first step in this effort has been to define both the essential and desirable attributes of a reference material for calibrating systems capable of measurements of dynamic displacement and strain. An international consortium of research laboratories, system designers, manufacturers and end-users has identified a list of attributes and members of the experimental mechanics community have been asked to weight the importance of these attributes. The attributes are being utilised to evaluate candidate designs for the reference material which have been generated through a series of brain-storming sessions within the consortium.
15. Can a safeguards accountancy system really detect an unauthorized removal
Energy Technology Data Exchange (ETDEWEB)
Ehinger, M.H.; Ellis, J.H.
1981-11-01
Theoretical investigations and system studies indicate safeguards material balance data from reprocessing plants can be used to detect unauthorized removals. Plant systems have been modeled and simulated data used to demonstrate the techniques. But how sensitive are the techniques when used with actual plant data. What is the effect of safeguards applications on plant operability. Can safeguards be acceptable to plant operators, and are there any benefits to be derived. The Barnwell Nuclear Fuel Plant (BNFP) has been devoted to answering these and other questions over the past several years. A computerized system of near-real-time accounting and in-process inventory has been implemented and demonstrated during actual plant test runs. Measured inventories and hourly material balance closures have been made to assess safeguards in an operating plant application. The tests have culminated in actual removals of material from the operating plant to investigate the response and measure the sensitivity of the safeguards and data evaluation system.
Energy Technology Data Exchange (ETDEWEB)
Miller, Mike [Idaho National Lab. (INL), Idaho Falls, ID (United States); Cipiti, Ben [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Demuth, Scott Francis [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Durkee, Jr., Joe W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Fallgren, Andrew James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Jarman, Ken [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Li, Shelly [Idaho National Lab. (INL), Idaho Falls, ID (United States); Meier, Dave [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Osburn, Laura Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pereira, Candido [Argonne National Lab. (ANL), Argonne, IL (United States); Dasari, Venkateswara Rao [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ticknor, Lawrence O. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Yoo, Tae-Sic [Idaho National Lab. (INL), Idaho Falls, ID (United States)
2017-01-30
The development of sustainable advanced nuclear fuel cycles is a long-term goal of the Office of Nuclear Energy’s (DOE-NE) Fuel Cycle Technologies program. The Material Protection, Accounting, and Control Technologies (MPACT) campaign is supporting research and development (R&D) of advanced instrumentation, analysis tools, and integration methodologies to meet this goal (Miller, 2015). This advanced R&D is intended to facilitate safeguards and security by design of fuel cycle facilities. The lab-scale demonstration of a virtual facility, distributed test bed, that connects the individual tools being developed at National Laboratories and university research establishments, is a key program milestone for 2020. These tools will consist of instrumentation and devices as well as computer software for modeling, simulation and integration.
Energy Technology Data Exchange (ETDEWEB)
Durkee, Joe W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Cipiti, Ben [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Demuth, Scott Francis [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Fallgren, Andrew James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Jarman, Ken [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Li, Shelly [Argonne National Lab. (ANL), Argonne, IL (United States); Meier, Dave [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Miller, Mike [Argonne National Lab. (ANL), Argonne, IL (United States); Osburn, Laura Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pereira, Candido [Argonne National Lab. (ANL), Argonne, IL (United States); Dasari, Venkateswara Rao [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ticknor, Lawrence O. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Yoo, Tae-Sic [Argonne National Lab. (ANL), Argonne, IL (United States)
2016-09-30
The development of sustainable advanced nuclear fuel cycles is a long-term goal of the Office of Nuclear Energy’s (DOE-NE) Fuel Cycle Technologies program. The Material Protection, Accounting, and Control Technologies (MPACT) campaign is supporting research and development (R&D) of advanced instrumentation, analysis tools, and integration methodologies to meet this goal (Miller, 2015). This advanced R&D is intended to facilitate safeguards and security by design of fuel cycle facilities. The lab-scale demonstration of a virtual facility, distributed test bed, that connects the individual tools being developed at National Laboratories and university research establishments, is a key program milestone for 2020. These tools will consist of instrumentation and devices as well as computer software for modeling, simulation and integration.
18. Material protection, control, and accounting enhancements through the Russian/US cooperative MPC & A program
Energy Technology Data Exchange (ETDEWEB)
Scott, S.C. [Los Alamos National Lab., NM (United States); Sude, S. [Brookhaven National Lab., Upton, NY (United States); Buckley, W.M. [Lawrence Livremore National Lab., CA (United States)] [and others
1997-11-01
The cooperative Russian/US Mining and Chemical Combine (Gorno-Khimichesky Kombinat, GKhK, also referred to as Krasnoyarsk-26) Materials Protection, Control, and Accounting (MPC & A) project was initiated in June 1996. Since then, the GKhK has collaborated with Brookhaven, Lawrence Livermore, Los Alamos, Oak Ridge, Pacific Northwest, and Sandia National Laboratories to test, evaluate, and implement MPC & A elements including bar codes, computerized nuclear material accounting software, nondestructive assay technologies, bulk measurement systems, seals, video surveillance systems, radio communication systems, metal detectors, vulnerability assessment tools, personnel access control systems, and pedestrian nuclear material portal monitors. This paper describes the strategy for implementation of these elements at the GKhK and the status of the collaborative efforts. 8 refs., 7 figs., 1 tab.
19. Assessment of the Accounting and Joint Accounting/Computer Information Systems Programs.
Science.gov (United States)
Appiah, John; Cernigliaro, James; Davis, Jeffrey; Gordon, Millicent; Richards, Yves; Santamaria, Fernando; Siegel, Annette; Lytle, Namy; Wharton, Patrick
This document presents City University of New York LaGuardia Community College's Department of Accounting and Managerial Studies assessment of its accounting and joint accounting/computer information systems programs report, and includes the following items: (1) description of the mission and goals of the Department of Accounting and Managerial…
20. Management accounting and integrated information systems
OpenAIRE
Rom, Anders
2008-01-01
A lag seems to exist between management accounting techniques and management accounting practices of organisations (Bjørnenak, 1997a). The accounting lag exists in spite of the interaction taking place between academia and practice in terms of researchers conducting field studies and management accountants attending research-based courses before and during their careers in practice.
1. Emerging smart materials systems
Energy Technology Data Exchange (ETDEWEB)
Strock, H.B. [Strock Technology Associates Inc., Holden, MA (United States)
1996-04-01
Smart materials systems are nonliving systems that integrate the functions of sensing, actuation, logic and control to respond adaptively to changes in their condition or the environment to which they are exposed, in a useful and usually repetitive manner. Smart materials possess both sensing and actuation capability. They can adaptively respond to changing stimuli, e.g., the variable darkening of photochromic glass or plastic on exposure to sunlight. Such passively smart materials behavior has relatively limited, although marketable, functionality.
2. Developing standard performance testing procedures for material control and accounting components at a site
Energy Technology Data Exchange (ETDEWEB)
Scherer, Carolynn P [Los Alamos National Laboratory; Bushlya, Anatoly V [ROSATOM, RUSSIA; Efimenko, Vladimir F [IPPE, RUSSIA; Ilyanstev, Anatoly [IPPE, RUSSIA; Regoushevsky, Victor I [IPPE, RUSSIA
2010-01-01
The condition of a nuclear material control and accountability system (MC&A) and its individual components, as with any system combining technical elements and documentation, may be characterized through an aggregate of values for the various parameters that determine the system's ability to perform. The MC&A system's status may be functioning effectively, marginally or not functioning based on a summary of the values of the individual parameters. This work included a review of the following subsystems, MC&A and Detecting Material Losses, and their respective elements for the material control and accountability system: (a) Elements of the MC&A Subsystem - Information subsystem (Accountancy/Inventory), Measurement subsystem, Nuclear Material Access subsystem, including tamper-indicating device (TID) program, and Automated Information-gathering subsystem; (b) Elements for Detecting Nuclear Material Loses Subsystem - Inventory Differences, Shipper/receiver Differences, Confirmatory Measurements and differences with accounting data, and TID or Seal Violations. In order to detect the absence or loss of nuclear material there must be appropriate interactions among the elements and their respective subsystems from the list above. Additionally this work includes a review of regulatory requirements for the MC&A system component characteristics and criteria that support the evaluation of the performance of the listed components. The listed components had performance testing algorithms and procedures developed that took into consideration the regulatory criteria. The developed MC&A performance-testing procedures were the basis for a Guide for MC&A Performance Testing at the material balance areas (MBAs) of State Scientific Center of the Russian Federation - Institute for Physics and Power Engineering (SSC RF-IPPE).
3. 10 CFR 74.41 - Nuclear material control and accounting for special nuclear material of moderate strategic...
Science.gov (United States)
2010-01-01
... 10 Energy 2 2010-01-01 2010-01-01 false Nuclear material control and accounting for special nuclear material of moderate strategic significance. 74.41 Section 74.41 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) MATERIAL CONTROL AND ACCOUNTING OF SPECIAL NUCLEAR MATERIAL Special Nuclear Material of Moderate Strategic Significance § 74.41...
4. 10 CFR 74.31 - Nuclear material control and accounting for special nuclear material of low strategic significance.
Science.gov (United States)
2010-01-01
... 10 Energy 2 2010-01-01 2010-01-01 false Nuclear material control and accounting for special nuclear material of low strategic significance. 74.31 Section 74.31 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) MATERIAL CONTROL AND ACCOUNTING OF SPECIAL NUCLEAR MATERIAL Special Nuclear Material of Low Strategic Significance § 74.31 Nuclear materia...
5. A Conexionist Intelligent System for Accounting
Directory of Open Access Journals (Sweden)
Florin APARASCHIVEI
2008-01-01
Full Text Available Neural networks are a computing paradigm developed from artificial intelligence and brain modelling’s fields, which lately has become very popular in business. Many researchers are seeing neural networks systems as solutions to business problems like modelling and forecasting, but accounting and audit were also touched by the new technology. The purpose of this paper is to present the ability of an artificial neural networks model to forecast and recognize patterns while analyzing company’s sales evolution. The monthly sales evolutions are considered a time-series and the target is to observe the ability of the investigated model to make predictions.
6. 7 CFR 1770.11 - Accounting system requirements.
Science.gov (United States)
2010-01-01
... 7 Agriculture 12 2010-01-01 2010-01-01 false Accounting system requirements. 1770.11 Section 1770..., DEPARTMENT OF AGRICULTURE (CONTINUED) ACCOUNTING REQUIREMENTS FOR RUS TELECOMMUNICATIONS BORROWERS Uniform System of Accounts § 1770.11 Accounting system requirements. (a) Each RUS borrower subject to...
7. The Reform of Management System of Accountants in China
Institute of Scientific and Technical Information of China (English)
2002-01-01
The common existing problems of the false processing of accounting information in China and the solution--the appointment system of accountants are analyzed in this paper, it is proposed that the reform of management systems of accountants--the appointment system of accountants should be applied temporally in particular conditions.
8. Nonlinear Dynamics of Structures with Material Degradation
Science.gov (United States)
Soltani, P.; Wagg, D. J.; Pinna, C.; Whear, R.; Briody, C.
2016-09-01
Structures usually experience deterioration during their working life. Oxidation, corrosion, UV exposure, and thermo-mechanical fatigue are some of the most well-known mechanisms that cause degradation. The phenomenon gradually changes structural properties and dynamic behaviour over their lifetime, and can be more problematic and challenging in the presence of nonlinearity. In this paper, we study how the dynamic behaviour of a nonlinear system changes as the thermal environment causes certain parameters to vary. To this end, a nonlinear lumped mass modal model is considered and defined under harmonic external force. Temperature dependent material functions, formulated from empirical test data, are added into the model. Using these functions, bifurcation parameters are defined and the corresponding nonlinear responses are observed by numerical continuation. A comparison between the results gives a preliminary insight into how temperature induced properties affects the dynamic response and highlights changes in stability conditions of the structure.
9. A proposed ecosystem services classification system to support green accounting
Science.gov (United States)
There are a multitude of actual or envisioned, complete or incomplete, ecosystem service classification systems being proposed to support Green Accounting. Green Accounting is generally thought to be the formal accounting attempt to factor environmental production into National ...
10. Introduction of elements of accounting systems of foreign countries in accounting practice in Ukraine
Directory of Open Access Journals (Sweden)
Shmatkovska Tatjana Oleksandrivna
2016-06-01
Full Text Available A comparative analysis of national and international approaches to regulation of accounting, generally modern system of accounting, defined the features of accounting principles to International Financial Reporting Standards and methodology developed countries, considered factors of influence on the development of national accounting systems for the analysis of developments domestic and foreign researchers, examined the nature of their influence and interdependence ‘relationship between them, identified and analyzed existing in the world management accounting practice models that differ in the degree of state regulation, austerity regulations for the implementation of accounting procedures, display order of business transactions in accounting accounts reveals trends of accounting in Ukraine at the present stage of integration of the economy into the world economy.
11. Critical Review On Management Information System And Accounting Information System
Directory of Open Access Journals (Sweden)
Galuh Tresna Murti
2015-08-01
Full Text Available This paper is aimed at investigating the correlation between management information system and accounting information system to gain better understanding of each system.After conducting reviews on available literatures it is concluded in this article that arguments among experts still clearly prevail about both system. Different arguments are not to be eliminated as each argument is supported by adequate literatures and difference in system is a common thing due to differences in experiences point of views and interests of the experts.This paper argues that since management information system is available in every part of an organization therefore accounting information system is the sub-system of management information system which main objective is to use organization information system effectively.
12. Modelling the effects of phase change materials on the energy use in buildings. Results of Experiments and System Dynamics Modelling
Energy Technology Data Exchange (ETDEWEB)
Prins, J.
2012-02-15
The current era is in need for more and more sustainable energy solutions. Phase Change Materials (PCM's) are a solution for a more sustainable build environment because they can help to reduce the energy use of buildings during heating and cooling of the indoor air. This paper presents the results of recent experiments that have been executed with test boxes. In addition a System Dynamics model has been developed to find out how PCM's can be used efficiently without testing in reality. The first experiment, in which PCM's were applied in a concrete floor, shows a reduction of peak temperatures with 4C {+-} 0.7C on maximum temperatures and over 1.5C {+-} 0.7C on minimum temperatures during warm periods. The model confirmed these findings, although the predicted reductions were slightly. During the second experiment more PCM's were applied by mounting them into the walls using gypsum plasterboard to increase the latent heat capacity. Remarkably, both the experimental set-up as the model showed that the increase of PCM's (of almost 98%) causes hardly any difference compared to the first situation. Adapting the exterior in a way to absorb more solar energy, increases the average indoor temperature but decreases the reduction of peak temperatures. Again the model confirmed these findings of the experiment. These results show that the effect of PCM's varies on different climatological contexts and with different construction components physics. This means no straight forward advice on the use of PCM's for a building design can be given. The solution for this problem is provided by the model, showing that the effects of PCM's can be modelled in order to use PCM's in an effective way in different climatological contexts and with different characteristics of construction components. The research shows that a simple model is already capable of predicting PCM performance in test boxes with reasonable accuracy. Therefore it can be
13. Development of DUPIC safeguards technology; development of web based nuclear material accounting program
Energy Technology Data Exchange (ETDEWEB)
Kim, J. T.; Choi, S. H.; Choi, S. J. [Kongju National University, Kongju (Korea)
2002-04-01
The purpose of this project is to develop the web-based digital image processing system with the client/server architecture based on TCP/IP to be able to search and manage image data at the remote place. This system provides a nuclear facility with the ability to track the movement of nuclear material and to control and account nuclear material at anywhere and anytime. Also, this system will be helpful to increase the efficiency of safeguards affairs. The developed web-based digital image processing system for tracking the movement of nuclear material and MC and A can be applied to DUPIC facility. The result of this project will eventually contribute to similar nuclear facilities as well as the effective implementation of DUPIC safeguards. In addition, it will be helpful to enhance international confidence build-up in the peaceful use of spent fuel material. 15 refs., 33 figs., 4 tabs. (Author)
14. From Governmental Accounting into National Accounts: Adjustments Diversity and Materiality with Evidence from the Iberian Countries’ Central Governments
Directory of Open Access Journals (Sweden)
Maria Antónia Jorge de Jesus
2014-09-01
Full Text Available In a context where governments around the world acknowledge a need for more informative governmental financial reporting to improve financial sustainability, the European Council is proposing that EU member states adopt International Public Sector Accounting Standards (IPSASs—which are recognized as also allowing improved reliability of government finance statistics—in all subsectors of the General Government Sector (GGS. Consequently, the Governmental Accounting (GA role of running and reporting on governments’ budgets for purposes of decisionmaking and accountability is changing to include being part of the EU budgetary and monetary policy, specifically within the Euro zone. Accordingly, the objective of this paper is twofold. First, it aims to start a debate in the literature about the ability of GA as it stands across Europe to meet the European System of National and Regional Accounts (ESA requirements concerning GGS data. This assumes particular relevance in a context where the two systems have to coexist, but given that budgetary reporting (GA is the main input to ESA reporting (NA, reconciliation between the two systems is required. The second objective is of a more technical nature—empirically demonstrating the diversity and materiality of the main adjustments to be made when converting GGS data from GA into NA. This is done by using evidence for Portugal and Spain, focusing on Central Government data for the period 2006–2009 and measuring their quantitative impact on the public (budgetary deficit. We conclude that GA systems as they are across EU do not meet ESA requirements, and further alignment is therefore needed to reduce adjustments as much as possible when translating data from GA into NA. Additionally, in the case of Portugal and Spain, the main findings show that the adjustments from GA into NA present great diversity for both of these Iberian countries. As for materiality, their impact is greater in Spain, but still
15. Influence Business Strategy On The Quality Of Accounting Information System
Directory of Open Access Journals (Sweden)
Meiryani
2015-02-01
Full Text Available Abstract Todaythe survival ofthe companyis largely determinedbythe ability ofcompaniesto competeinthe market so improvement on the quality of accounting information system is needed. Companies use accounting information system as a tool to generate information that managers can make decisions. To be able to take the right decisions necessary quality of accounting information systems. In view of the above this paper considers the Influence Of Business Strategy On The Quality Of Accounting Information System. The study was a theoretical research which considered the roles of business strategy in quality of accounting information system. From studies carried out this paper concludes that business strategy having improved quality of accounting information system.
16. Dynamic Interactive Learning Systems
Science.gov (United States)
Sabry, Khaled; Barker, Jeff
2009-01-01
This paper reviews and discusses the notions of interactivity and dynamicity of learning systems in relation to information technologies and design principles that can contribute to interactive and dynamic learning. It explores the concept of dynamic interactive learning systems based on the emerging generation of information as part of a…
17. Development of in-situ observation system of dynamic contact interface between dies and materials during microforming operation
Directory of Open Access Journals (Sweden)
Shimizu Tetsuhide
2015-01-01
Full Text Available Application of diamond like carbon (DLC films are reported in several microforming processes, in view of its great tribological performance owe to the low friction and the high chemical stability. However, due to its high internal residual stress, the film properties with the low adhesion strength and the high wear rate under severe tribological conditions are still remain as technical issues. However, since the dynamic variation of the contact state cannot be observed during the forming operation, it is difficult to recognize the origin and the influential tribological factors of tool life for DLC coated microforming die. Therefore, the appropriate DLC film properties for the contact state in microforming operation have not been clarified. To observe the dynamic variation of the contact state during the microforming operation, present study developed a novel microforming die assembly installed the in-situ observation system with silica glass die and high speed recording camera. By using this system, the dynamic delamination behaviour of DLC films during the progressive micro-bending process was successfully demonstrated. The influential factors for the durability of DLC coated microdies were discussed.
18. Dynamics of stochastic systems
CERN Document Server
Klyatskin, Valery I
2005-01-01
Fluctuating parameters appear in a variety of physical systems and phenomena. They typically come either as random forces/sources, or advecting velocities, or media (material) parameters, like refraction index, conductivity, diffusivity, etc. The well known example of Brownian particle suspended in fluid and subjected to random molecular bombardment laid the foundation for modern stochastic calculus and statistical physics. Other important examples include turbulent transport and diffusion of particle-tracers (pollutants), or continuous densities (''''oil slicks''''), wave propagation and scattering in randomly inhomogeneous media, for instance light or sound propagating in the turbulent atmosphere.Such models naturally render to statistical description, where the input parameters and solutions are expressed by random processes and fields.The fundamental problem of stochastic dynamics is to identify the essential characteristics of system (its state and evolution), and relate those to the input parameters of ...
19. Development and Appraisal of Multiple Accounting Record System (Mars).
Science.gov (United States)
Yu, H C; Chen, M C
2016-01-01
The aim of the system is to achieve simplification of workflow, reduction of recording time, and increase the income for the study hospital. The project team decided to develop a multiple accounting record system that generates the account records based on the nursing records automatically, reduces the time and effort for nurses to review the procedure and provide another note of material consumption. Three configuration files were identified to demonstrate the relationship of treatments and reimbursement items. The workflow was simplified. The nurses averagely reduced 10 minutes of daily recording time, and the reimbursement points have been increased by 7.49%. The project streamlined the workflow and provides the institute a better way in finical management.
20. The system of account and control of logistics costs
Directory of Open Access Journals (Sweden)
Khayrullin Rustam Zinnatullovich
Full Text Available The process of organization of civil engineering provides the delivery of construction materials, equipment to the civil engineering objects in the required quantities at the specified time. Effective tool for solving this problem is logistics. The basic components of logistics costs, which occupy the largest share in the sum of all logistics costs, are transportation costs and storage costs. The civil engineering industry is very promising for the use of outsourcing. The main part of works on providing material and technical resources in most cases is transferred to the outsourcing of other companies, including the group of companies forming the holding. In large holding companies the chain of movement of materials, goods and productions: purchase of materials and goods, completion materials, production structures, storage, movement, transportation, etc. may include several companies belonging in holding. The goods can be moved from one warehouse to another, with or without change of the owner of goods. Each company is obliged to show each movement of goods in their financial accounting. During the goods’ movement within a group of companies from one storage to another, from one owner to another, the total costs of the goods rise. Sales within a group of companies lead, as a rule, to a gain by one of the companies and the logistic expenses of another company. Selling to a consumer provides a profit to the seller company. Therefore, the problem of adequate allocation of logistics expenses and profits between separate legal entity and the task of continuous accounting and control of logistics costs and earnings in large companies, is vital. The automated system for accounting and controlling of logistics costs is suggested. The developed system allows controlling logistics costs of refining, storage and transportation for each ton, pieces, linear or square meters of the shipped cargoes. The System is based on complex algorithms of distribution
1. Dynamic Polymer Systems with Self-regulated Secretion for the Control of Surface Properties and Material Healing
Science.gov (United States)
2017-08-23
secretes fluids, mediating defence, adhesion, wound healing , temperature—often several of these at once—through tightly self-regulated release systems6–9...s ) Silicone oil (wt%) a b e c Liquid medium Diffuse Open Close Damage Secrete Self- heal Gel phase St re ss (M Pa ) Strain (ii) (iii) (ii) 0 s...Secretion for the Control of Surface Properties and Material Healing Harvard University CAmbridge MA 242 Office of Naval Research Arlington 46 242 1
2. The Accounting Network: how financial institutions react to systemic crisis
CERN Document Server
Flori, Andrea; Puliga, Michelangelo; Chessa, Alessandro; Pammolli, Fabio
2016-01-01
The role of Network Theory in the study of the financial crisis has been widely spotted in the latest years. It has been shown how the network topology and the dynamics running on top of it can trigger the outbreak of large systemic crisis. Following this methodological perspective we introduce here the Accounting Network, i.e. the network we can extract through vector similarities techniques from companies' financial statements. We build the Accounting Network on a large database of worldwide banks in the period 2001-2013, covering the onset of the global financial crisis of mid-2007. After a careful data cleaning, we apply a quality check in the construction of the network, introducing a parameter (the Quality Ratio) capable of trading off the size of the sample (coverage) and the representativeness of the financial statements (accuracy). We compute several basic network statistics and check, with the Louvain community detection algorithm, for emerging communities of banks. Remarkably enough sensible region...
3. Supercapacitors materials, systems and applications
CERN Document Server
Lu, Max; Frackowiak, Elzbieta
2013-01-01
Written by an international group of leading experts from both academia and industry, this is the first comprehensive book on the topic for 10 years. Taking into account the commercial interest in these systems and the scientific and technological developments over the past decade, all important materials and systems are covered, with several chapters devoted to topics of direct industrial relevance.The book starts by providing an introduction to the general principles of electrochemistry, the properties of electrochemical capacitors, and electrochemical characterization techniques. There
4. Material control and accounting in the Department of Energy's nuclear fuel complex
Energy Technology Data Exchange (ETDEWEB)
None
1989-01-01
Material control and accounting takes place within an envelope of activities related to safeguards and security, as well as to safety, health, and environment, all of which need to be managed to assure that the entire nuclear fuel complex can operate in a societally accepted manner. Within this envelope the committee was directed to carry out the following scope of work: (1) Review the MCandA systems in use at selected DOE facilities that are processing special nuclear material (SNM) in various physical and chemical forms. (2) Design and convene a workshop for senior representatives from each of DOE's facilities on the flows and inventories of nuclear materials. (3) Plan and conduct a series of site visits to each of the facilities to observe first hand the processing operations and the related MCandA systems. (4) Review the potential improvement in overall safeguard systems effectiveness, as measured by expected reduction in inventory difference control limits and inventory differences for materials balance accounts and facilities, or other criteria as appropriate. Indicate how this affects the relative degree of uncertainty in the system. (5) Review the efficiency of operating the MCandA system with and without the upgrading options and assess whether upgrading will contribute further efficiencies in operation, which may reduce many of the current operations costs. Determine if the current system is cost-effective. (6) Recommend the most promising technical approaches for further development by DOE and further study as warranted.
5. Temperature dynamic models of heat exchanger for photosensitive material coating and drying processes; Kanko zairyo tofu kanso process ni okeru kucho system no ondo doteki model
Energy Technology Data Exchange (ETDEWEB)
Kido, K.; Sato, N.; Shimoji, M. [Konica Co. Ltd., Tokyo (Japan); Nakanishi, E. [Kobe University, Kobe (Japan). Faculty of Engineering
1996-01-20
Nonlinear and linear temperature dynamic models of a heat exchanger were investigated for air conditioning control of coating and drying processes for photosensitive materials. The nonlinear model was derived from heat balance based on the assumption of lumped parameter system that the heat exchanger is divided into small parts in the direction of flow (divided cell model). In each part, the temperature of the heating fluid, heated fluid and heat transfer tube with fin are assumed to be uniform. Parameters involved in this model were estimated from experimental data of the step response characteristics of temperature. The linear model is obtained by linearizing this nonlinear model. It was confirmed that the dynamic behavior of temperature can be successfully expressed by both nonlinear and linear models. Both models are considered to be utilizable for process analysis and control system design of the air conditioning system under consideration. 1 ref., 13 figs., 2 tabs.
6. The Use of Fast Neutron Detection for Materials Accountability
Science.gov (United States)
Nakae, L. F.; Chapline, G. F.; Glenn, A. M.; Kerr, P. L.; Kim, K. S.; Ouedraogo, S. A.; Prasad, M. K.; Sheets, S. A.; Snyderman, N. J.; Verbeke, J. M.; Wurtz, R. E.
2014-02-01
For many years at LLNL, we have been developing time-correlated neutron detection techniques and algorithms for applications such as Arms Control, Threat Detection and Nuclear Material Assay. Many of our techniques have been developed specifically for the relatively low efficiency (a few percent) inherent in man-portable systems. Historically, thermal neutron detectors (mainly 3He) were used, taking advantage of the high thermal neutron interaction cross-sections, but more recently we have been investigating the use of fast neutron detection with liquid scintillators, inorganic crystals, and in the near future, pulse-shape discriminating plastics that respond over 1000 times faster (nanoseconds versus tens of microseconds) than thermal neutron detectors. Fast neutron detection offers considerable advantages, since the inherent nanosecond production timescales of fission and neutron-induced fission are preserved and measured instead of being lost in the thermalization of thermal neutron detectors. We are now applying fast neutron technology to the safeguards regime in the form of high efficiency counters. Faster detector response times and sensitivity to neutron momentum show promise in measuring, differentiating, and assaying samples that have modest to very high count rates, as well as mixed neutron sources (e.g., Pu oxide or Mixed Cm and Pu). Here we report on measured results with our existing liquid scintillator array and promote the design of a nuclear material assay system that incorporates fast neutron detection, including the surprising result that fast liquid scintillator becomes competitive and even surpasses the precision of 3He counters measuring correlated pairs in modest (kg) samples of plutonium.
7. 45 CFR 1301.13 - Accounting system certification.
Science.gov (United States)
2010-10-01
... 45 Public Welfare 4 2010-10-01 2010-10-01 false Accounting system certification. 1301.13 Section... START PROGRAM HEAD START GRANTS ADMINISTRATION General Requirements § 1301.13 Accounting system... shall submit an accounting system certification, prepared by an independent auditor, stating that...
8. 34 CFR 200.12 - Single State accountability system.
Science.gov (United States)
2010-07-01
... 34 Education 1 2010-07-01 2010-07-01 false Single State accountability system. 200.12 Section 200... Improving Basic Programs Operated by Local Educational Agencies State Accountability System § 200.12 Single State accountability system. (a)(1) Each State must demonstrate in its State plan that the State...
9. MATHEMATICAL MODEL FOR ESTIMATION OF MECHANICAL SYSTEM CONDITION IN DYNAMICS
Directory of Open Access Journals (Sweden)
D. N. Mironov
2011-01-01
Full Text Available The paper considers an estimation of a complicated mechanical system condition in dynamics with due account of material degradation and accumulation of micro-damages. An element of continuous medium has been simulated and described with the help of a discrete element. The paper contains description of a model for determination of mechanical system longevity in accordance with number of cycles and operational period.
10. Media Accountability Systems: Models, proposals and outlooks
Directory of Open Access Journals (Sweden)
Luiz Martins da Silva
2007-06-01
Full Text Available This paper analyzes one of the basic actions of SOS-Imprensa, the mechanism to assure Media Accountability with the goal of proposing a synthesis of models for the Brazilian reality. The article aims to address the possibilities of creating and improving mechanisms to stimulate the democratic press process and to mark out and assure freedom of speech and personal rights with respect to the media. Based on the Press Social Responsibility Theory, the hypothesis is that the experiences analyzed (Communication Council, Press Council, Ombudsman and Readers Council are alternatives for accountability, mediation and arbitration, seeking visibility, trust and public support in favor of fairer media.
11. Securing data accountability in decentralized systems
NARCIS (Netherlands)
Corin, Ricardo; Galindo, David; Hoepman, Jaap-Henk
2006-01-01
We consider a decentralized setting in which agents exchange data along with usage policies. Agents may violate the intended usage policies, although later on auditing authorities may verify the agents’ data accountability with respect to the intended policies. Using timestamping and signature schem
12. Factors That Influence Accounting Information System Implementation And Accounting Information Quality
Directory of Open Access Journals (Sweden)
Ruhul Fitrios
2015-08-01
Full Text Available This article aims to determine the effect of top management commitment and user training on the implementation of accounting information systems. This study was conducted at hospitals type A B and C in the region of Riau Province Indonesia. The number of hospitals that fulfill the criteria to have the accounting information system for 42 hospitals. Totally 34 questionnaires are returned by respondents and can be processed. Data obtained are processed using SPSS version 21. The result showed that the top management commitment and user training affect the accounting information system implementation at hospitals type A B and C in the province of Riau. The results also showed that the implementation of accounting information system affect the accounting information quality.
13. Implementation Status of Accrual Accounting System in Health Sector
OpenAIRE
2014-01-01
Introduction: Management of financial resources in health systems is one of the major issues of concern for policy makers globally. As a sub-set of financial management, accounting system is of paramount importance. In this paper, which presents part of the results of a wider research project on transition process from a cash accounting system to an accrual accounting system, we look at the impact of components of change on implementation of the new system. Implementing changes is fraught wit...
14. Bisimulation of Dynamical Systems
NARCIS (Netherlands)
Schaft, Arjan van der
2004-01-01
A general notion of bisimulation is studied for dynamical systems. An algebraic characterization of bisimulation together with an algorithm for computing the maximal bisimulation relation is derived using geometric control theory. Bisimulation of dynamical systems is shown to be a concept which
15. An Internet-Based Accounting Information Systems Project
Science.gov (United States)
Miller, Louise
2012-01-01
This paper describes a student project assignment used in an accounting information systems course. We are now truly immersed in the internet age, and while many required accounting information systems courses and textbooks introduce database design, accounting software development, cloud computing, and internet security, projects involving the…
16. 7 CFR 1767.12 - Accounting system requirements.
Science.gov (United States)
2010-01-01
... Borrowers, herein, which prescribes accounting principles to be applied to specific factual circumstances. ... 7 Agriculture 12 2010-01-01 2010-01-01 false Accounting system requirements. 1767.12 Section 1767..., DEPARTMENT OF AGRICULTURE (CONTINUED) ACCOUNTING REQUIREMENTS FOR RUS ELECTRIC BORROWERS Uniform System...
17. Comparative Analysis on Two Accounting Systems of Rural Economic Originations
Institute of Scientific and Technical Information of China (English)
2011-01-01
In order to normalize the financial account of two kinds of economic organizations,the comparative analysis is conducted on the Accounting System of Village Collective Economic Organization and Accounting System of Farmers’ Cooperatives(Trial) issued by the Ministry of Finance.The comparison points out that application and accounting principles of the two kinds of accounting systems are different.The differences and similarities of the five accounting elements are analyzed including property,liabilities,rights of owners,costs and profits and losses,as well as the reasons of the differences and similarities.Results show that both of the two accounting systems reflect the principles of simplification and clarification.The village collective accounting system works in rural village committee,which acts the administrative duties,the features of concerted benefits of it is showed.While the accounting system of farmers’ cooperatives is based on the village collective accounting system and combines the norms of accounting system of enterprises,so the system represents the demands of collaboration and profit-making.
18. Transition Office Management and Accounting System
Data.gov (United States)
US Agency for International Development — TOMAS combined over 20 previously separate systems into one fully integrated management system covering budget, finance, procurement, travel, and emergency contact...
19. Material protection control and accounting program activities at the electrochemical plant
Energy Technology Data Exchange (ETDEWEB)
McAllister, S.
1997-11-14
The Electrochemical Plant (ECP) is the one of the Russian Federations four uranium enrichment plants and one of three sites in Russia blending high enriched uranium (HEU) into commercial grade low enriched uranium. ECP is located approximately 200 km east of Krasnoyarsk in the closed city of Zelenogorsk (formerly Krasnoyarsk- 45). DOEs MPC&A program first met with ECP in September of 1996. The six national laboratories participating in DOEs Material Protection Control and Accounting program are cooperating with ECP to enhance the capabilities of the physical protection, access control, and nuclear material control and accounting systems. The MPC&A work at ECP is expected to be completed during fiscal year 2001.
20. Production of an English/Russian glossary of terminology for nuclear materials control and accounting
Energy Technology Data Exchange (ETDEWEB)
Schachowskoj, S.; Smith, H.A. Jr.
1995-05-01
The program plans for Former Soviet Union National Nuclear Materials Control and Accounting (MC and A) Systems Enhancements call for the development of an English/Russian Glossary of MC and A terminology. This glossary was envisioned as an outgrowth of the many interactions, training sessions, and other talking and writing exercises that would transpire in the course of carrying out these programs. This report summarizes the status of the production of this glossary, the most recent copy of which is attached to this report. The glossary contains over 950 terms and acronyms associated with nuclear material control and accounting for safeguards and nonproliferation. This document is organized as follows: English/Russian glossary of terms and acronyms; Russian/English glossary of terms and acronyms; English/Russian glossary of acronyms; and Russian/English glossary of acronyms.
1. Production of an English/Russian glossary of terminology for nuclear materials control and accounting
Energy Technology Data Exchange (ETDEWEB)
Schachowskoj, S.; Smith, H.A. Jr.
1995-05-01
The program plans for Former Soviet Union National Nuclear Materials Control and Accounting (MC and A) Systems Enhancements call for the development of an English/Russian Glossary of MC and A terminology. This glossary was envisioned as an outgrowth of the many interactions, training sessions, and other talking and writing exercises that would transpire in the course of carrying out these programs. This report summarizes the status of the production of this glossary, the most recent copy of which is attached to this report. The glossary contains over 950 terms and acronyms associated with nuclear material control and accounting for safeguards and nonproliferation. This document is organized as follows: English/Russian glossary of terms and acronyms; Russian/English glossary of terms and acronyms; English/Russian glossary of acronyms; and Russian/English glossary of acronyms.
2. Stability of dynamical systems
CERN Document Server
Liao, Xiaoxin; Yu, P 0
2007-01-01
The main purpose of developing stability theory is to examine dynamic responses of a system to disturbances as the time approaches infinity. It has been and still is the object of intense investigations due to its intrinsic interest and its relevance to all practical systems in engineering, finance, natural science and social science. This monograph provides some state-of-the-art expositions of major advances in fundamental stability theories and methods for dynamic systems of ODE and DDE types and in limit cycle, normal form and Hopf bifurcation control of nonlinear dynamic systems.ʺ Presents
3. System of Health Accounts and Health Satellite Accounts : Application in Low- and Middle-Income Countries
NARCIS (Netherlands)
Nakhimovsky, S.; Hernandez-Peña, P.; van Mosseveld, C.; Palacios, A.
2014-01-01
Health accounting data that show economic and financial resource flows within a health system are critical to informing health and economic policy – at both national and international levels. However, countries vary widely in their health accounting histories as well as the demand for and capacity t
4. System of Health Accounts and Health Satellite Accounts : Application in Low- and Middle-Income Countries
NARCIS (Netherlands)
Nakhimovsky, S.; Hernandez-Peña, P.; van Mosseveld, C.; Palacios, A.
2014-01-01
Health accounting data that show economic and financial resource flows within a health system are critical to informing health and economic policy – at both national and international levels. However, countries vary widely in their health accounting histories as well as the demand for and capacity
5. ACCOUNTING INFORMATION SYSTEM - QUALITATIVE CHARACTERISTICS AND THE IMPORTANCE OF ACCOUNTING INFORMATION AT TRADE ENTITIES
Directory of Open Access Journals (Sweden)
2015-03-01
Full Text Available Financial and accounting information systems, today, no longer are the traditional ones, they are subject to the normalisation and harmonisation, in the idea of globalization, and as a natural consequence of this situation, the users of accounting information require more and more diverse information from these systems. The economic entities in general, and those in the trade, in particular, performance management, management of the current situation, with multiple phenomena of crisis, require substantiation of decisions on the basis of a system of real information, pertinent, relevant and provided in a timely manner (Radu, 2011 [7]. Apart from users and goals of information provided by entities of the accounting information system of trade entities, they must have certain qualitative characteristics that facilitate the process of interpretation and use of accounting information. At the same time they are needed because their accounting information through its better goal, to represent the support base for the elaboration of certain decisions by those interested. In this article I propose to introduce qualitative characteristics of accounting information provided by IASB (International Accounting Standards Board, which, incidentally, have been taken up initially by the Romanian accounting regulations, with their subsequent amendments and additions, so far, because, in the end, as a conclusion, I consider that I should be noted that these qualities cannot be effective unlessin turn, the users themselves have the quality to have the knowledge required to understand the information that is intended for them.
6. Dynamic teaching materials for ESSLLI
NARCIS (Netherlands)
Bernardi, R.B.; Dahn, I.; Mishne, G.A.; Moortgat, M.; de Rijke, M.; Uszkoreit, H.; Monachesi, P.; Vertan, C.; von Hahn, W.
2004-01-01
In the context of the European Network of Excellence in Computational Logic (CoLogNet, http://www.colognet.org/), the European Association for Logic, Language and Computation (FoLLI, http://www.folli.org) has started a project on E-Learning in Computational Logic and the development of Dynamic Teach
7. Dynamic teaching materials for ESSLLI
NARCIS (Netherlands)
Bernardi, R.B.; Dahn, I.; Mishne, G.A.; Moortgat, M.; de Rijke, M.; Uszkoreit, H.; Monachesi, P.; Vertan, C.; von Hahn, W.
2004-01-01
In the context of the European Network of Excellence in Computational Logic (CoLogNet, http://www.colognet.org/), the European Association for Logic, Language and Computation (FoLLI, http://www.folli.org) has started a project on E-Learning in Computational Logic and the development of Dynamic Teach
8. Dynamic teaching materials for ESSLLI
NARCIS (Netherlands)
Bernardi, R.B.; Dahn, I.; Mishne, G.A.; Moortgat, M.; de Rijke, M.; Uszkoreit, H.; Monachesi, P.; Vertan, C.; von Hahn, W.
2004-01-01
In the context of the European Network of Excellence in Computational Logic (CoLogNet, http://www.colognet.org/), the European Association for Logic, Language and Computation (FoLLI, http://www.folli.org) has started a project on E-Learning in Computational Logic and the development of Dynamic
9. Influence Business Process On The Quality Of Accounting Information System
Directory of Open Access Journals (Sweden)
Meiryani
2015-01-01
Full Text Available Abstract The purpose of this study was to determine the influence of business process to the quality of the accounting information system. This study aims to examine the influence of business process on the quality of the information system of accounting information system. The study was theoritical research which considered the roles of business process on quality of accounting information system which use secondary data collection. The results showed that the business process have a significant effect on the quality of accounting information systems.
10. Inventory management in the environment and the theory of constraints management accounting system throughput accounting
Directory of Open Access Journals (Sweden)
Elsukova Tatiana Vasilevna
2014-02-01
Full Text Available This article analyzes the techniques and methods of inventory management company with the information of a management accounting system based on the principles of the theory of constraints, both financial and non-financial.
11. Inventory management in the environment and the theory of constraints management accounting system throughput accounting
OpenAIRE
Elsukova Tatiana Vasilevna
2014-01-01
This article analyzes the techniques and methods of inventory management company with the information of a management accounting system based on the principles of the theory of constraints, both financial and non-financial.
CERN Document Server
Pilyugin, Sergei Yu
1999-01-01
This book is an introduction to the theory of shadowing of approximate trajectories in dynamical systems by exact ones. This is the first book completely devoted to the theory of shadowing. It shows the importance of shadowing theory for both the qualitative theory of dynamical systems and the theory of numerical methods. Shadowing Methods allow us to estimate differences between exact and approximate solutions on infinite time intervals and to understand the influence of error terms. The book is intended for specialists in dynamical systems, for researchers and graduate students in the theory of numerical methods.
13. Fractional Dynamical Systems
CERN Document Server
Edelman, Mark
2014-01-01
In this paper the author presents the results of the preliminary investigation of fractional dynamical systems based on the results of numerical simulations of fractional maps. Fractional maps are equivalent to fractional differential equations describing systems experiencing periodic kicks. Their properties depend on the value of two parameters: the non-linearity parameter, which arises from the corresponding regular dynamical systems; and the memory parameter which is the order of the fractional derivative in the corresponding non-linear fractional differential equations. The examples of the fractional Standard and Logistic maps demonstrate that phase space of non-linear fractional dynamical systems may contain periodic sinks, attracting slow diverging trajectories, attracting accelerator mode trajectories, chaotic attractors, and cascade of bifurcations type trajectories whose properties are different from properties of attractors in regular dynamical systems. The author argues that discovered properties s...
14. Identifying Employer Needs from Accounting Information Systems Programs
Science.gov (United States)
Dillon, Thomas W.; Kruck, S. E.
2008-01-01
As the need for new hires with accounting and information technology knowledge increases, a new major in accounting information systems (AIS) has emerged. This new AIS degree is a hybrid of accounting concepts and common business subjects combined with key information technology issues. Employers were presented with 56 core content areas found in…
15. Identifying Employer Needs from Accounting Information Systems Programs
Science.gov (United States)
Dillon, Thomas W.; Kruck, S. E.
2008-01-01
As the need for new hires with accounting and information technology knowledge increases, a new major in accounting information systems (AIS) has emerged. This new AIS degree is a hybrid of accounting concepts and common business subjects combined with key information technology issues. Employers were presented with 56 core content areas found in…
16. 14 CFR Sec. 1-4 - System of accounts coding.
Science.gov (United States)
2010-01-01
... General Accounting Provisions Sec. 1-4 System of accounts coding. (a) A four digit control number is... digit code assigned to each profit and loss account denote a detailed area of financial activity or... sequentially within blocks, designating more general classifications of financial activity and...
17. Risk Analysis of Accounting Information System Infrastructure
OpenAIRE
MIHALACHE, Arsenie-Samoil
2011-01-01
National economy and security are fully dependent on information technology and infrastructure. At the core of the information infrastructure society relies on, we have the Internet, a system designed initially as a scientists’ forum for unclassified research. The use of communication networks and systems may lead to hazardous situations that generate undesirable effects such as communication systems breakdown, loss of data or taking the wrong decisions. The paper studies the risk analysis of...
18. Accounting System in Croatian Public Healthcare Organizations: an Empirical Analysis
Directory of Open Access Journals (Sweden)
Davor VAŠIČEK
2010-06-01
Full Text Available In considering the adequacy of adopting accruals and IPSASs, this paper tests the appropriateness of existing modified accrual accounting and financial reporting system in Croatian public healthcare sector. The paper indicates that accounting information system contains discrepancies and constraints in assuring true and fair view of organization’s financial position and performance. Our statistics confirms low level of cost and managerial accounting methods development, and external and internal financial reporting convergence.Having in mind its specificities, we argue that Croatian public healthcare sector represents a segmental accounting subsystem within the integral public sector accounting framework, where accruals implementation might prove justifiable.
19. ON PERIODIC DYNAMICAL SYSTEMS
Institute of Scientific and Technical Information of China (English)
LU WENLIAN; CHEN TIANPING
2004-01-01
The authors investigate the existence and the global stability of periodic solution for dynamical systems with periodic interconnections, inputs and self-inhibitions. The model is very general, the conditions are quite weak and the results obtained are universal.
20. Dynamic performance management system
Institute of Scientific and Technical Information of China (English)
2006-01-01
An integrated, efficient and effective performance management system, "dynamic performance management system", is presented, which covers the entire performance management process including measures design, analysis, and dynamic update. The analysis of performance measures using causal loop diagrams, qualitative inference and analytic network process is mainly discussed. A real world case study is carried out throughout the paper to explain how the framework works. A software tool for DPMS, Performance Analyzer, is also introduced.
1. Simultaneous dynamic electrical and structural measurements of functional materials
Energy Technology Data Exchange (ETDEWEB)
Vecchini, C.; Stewart, M.; Muñiz-Piniella, A.; Wooldridge, J. [National Physical Laboratory, Hampton Road, Teddington TW11 0LW (United Kingdom); Thompson, P.; McMitchell, S. R. C.; Bouchenoire, L.; Brown, S.; Wermeille, D.; Lucas, C. A. [XMaS, The UK-CRG, ESRF-The European Synchrotron, CS40220, F-38043, Grenoble Cedex 09 (France); Department of Physics, University of Liverpool, Liverpool L69 3BX (United Kingdom); Lepadatu, S. [National Physical Laboratory, Hampton Road, Teddington TW11 0LW (United Kingdom); Jeremiah Horrocks Institute, University of Central Lancashire, Preston PR1 2HE (United Kingdom); Bikondoa, O.; Hase, T. P. A. [XMaS, The UK-CRG, ESRF-The European Synchrotron, CS40220, F-38043, Grenoble Cedex 09 (France); Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Lesourd, M. [ESRF-The European Synchrotron, CS40220, F-38043, Grenoble Cedex 09 (France); Dontsov, D. [SIOS Meßtechnik GmbH, Am Vogelherd 46, 98693 Ilmenau (Germany); Cain, M. G. [National Physical Laboratory, Hampton Road, Teddington TW11 0LW (United Kingdom); Electrosciences Ltd., Farnham, Surrey GU9 9QT (United Kingdom)
2015-10-15
A new materials characterization system developed at the XMaS beamline, located at the European Synchrotron Radiation Facility in France, is presented. We show that this new capability allows to measure the atomic structural evolution (crystallography) of piezoelectric materials whilst simultaneously measuring the overall strain characteristics and electrical response to dynamically (ac) applied external stimuli.
2. Dynamic properties of ceramic materials
Energy Technology Data Exchange (ETDEWEB)
Grady, D.E. [Sandia National Labs., Albuquerque, NM (United States). Experimental Impact Physics Dept.
1995-02-01
The present study offers new data and analysis on the transient shock strength and equation-of-state properties of ceramics. Various dynamic data on nine high strength ceramics are provided with wave profile measurements, through velocity interferometry techniques, the principal observable. Compressive failure in the shock wave front, with emphasis on brittle versus ductile mechanisms of deformation, is examined in some detail. Extensive spall strength data are provided and related to the theoretical spall strength, and to energy-based theories of the spall process. Failure waves, as a mechanism of deformation in the transient shock process, are examined. Strength and equation-of-state analysis of shock data on silicon carbide, boron carbide, tungsten carbide, silicon dioxide and aluminum nitride is presented with particular emphasis on phase transition properties for the latter two. Wave profile measurements on selected ceramics are investigated for evidence of rate sensitive elastic precursor decay in the shock front failure process.
3. Recent developments in dynamic testing of materials
Directory of Open Access Journals (Sweden)
Gilat Amos
2015-01-01
Full Text Available New techniques for dynamic characterization of materials that have been developed in the last three years (since the last DYMAT conference in 2012, and results from recent dynamic testing of Inconel 718 are presented. The first development is a dynamic punch test in which three dimensional Digital Image Correlation (DIC is used to measure the deformation of the rear surface of a specimen as it being penetrated. The second experimental technique that is under development is a dynamic tension experiment in which full-field strain measurement with DIC and full-field temperature measurement are done simultaneously during the test.
4. Accounting for the Danish Public School System
DEFF Research Database (Denmark)
Graversen, Marie Engstrøm
the opportunity/danger for more adverse behavioral responses to be triggered. The field studies make plain that the level of competitive pressure and budgetary risk are very influential in ensuring that the funding model is more than a reimbursement system, making it instead a mean through which providers...
5. Nuclear Material Accountancy Assessment Technical Measures in Nuclear Centrifuge Enrichment Facility
Institute of Scientific and Technical Information of China (English)
2011-01-01
Nuclear material accountancy assessment is the main technical measures for nuclear materials regulatory. It is an important basis to detect theft, loss and the illegal diversion of nuclear material. In order to implement the control of nuclear materials for nuclear facilities,
6. Fostering a culture of accountability through a performance appraisal system.
Science.gov (United States)
Gillani, Asmita; Jarvi, Kristine; De Angelis, Andrew
2005-01-01
The current climate in Canadian healthcare requires that healthcare providers be more accountable to the government and other stakeholders. Using a well-structured performance appraisal system that is based on quantifiable objectives and standards, a high level of accountability can be achieved. The objective of this article is to demonstrate how a sound performance appraisal system can increase accountability and performance of healthcare organizations and their senior management.
7. THE AUTOMATION SYSTEM OF ACCOUNTING SPORTING ACTIVITIES
Directory of Open Access Journals (Sweden)
A. A. Shpinkovski
2016-12-01
Full Text Available In recent years become a popular healthy lifestyle. Sport is an activity that serves the public interest by implementing educational, preparatory and communicative function, but not a constant specialty (profession person. The development of current sports, requires resources that will not only automate the work of the organizers of the competition with the information, but also improve its effectiveness. One of the progressive sports at the moment is powerlifting (power triathlon. The proposed information system is an automated workplace of the organizer. During the implementation of the information system support sports competitions were performed system design using UML diagrams. It is possible to understand the tasks that must be done in the implementation of the program. The program is organized so that you can quickly and simply add all data about upcoming competitions: the name, location, date, the composition of the referee. After receiving information about the athletes, coaches, sports clubs, to make an application for participation in the competition. Also, the organizer has the ability to view statistics about the coaches, referees, participants, based on the information entered into the database earlier. A detailed user guide program. A functional testing and usability. Recommendations for further development of the software product.
8. Material control in nuclear fuel fabrication facilities. Part II. Accountability, instrumentation and measurement techniques in fuel fabrication facilities
Energy Technology Data Exchange (ETDEWEB)
Borgonovi, G.M.; McCartin, T.J.; McDaniel, T.; Miller, C.L.; Nguyen, T.
1978-01-01
This report describes the measurement techniques, the instrumentation, and the procedures used in accountability and control of nuclear materials, as they apply to fuel fabrication facilities. A general discussion is given of instrumentation and measurement techniques which are presently used being considered for fuel fabrication facilities. Those aspects which are most significant from the point of view of satisfying regulatory constraints have been emphasized. Sensors and measurement devices have been discussed, together with their interfacing into a computerized system designed to permit real-time data collection and analysis. Estimates of accuracy and precision of measurement techniques have been given, and, where applicable, estimates of associated costs have been presented. A general description of material control and accounting is also included. In this section, the general principles of nuclear material accounting have been reviewed first (closure of material balance). After a discussion of the most current techniques used to calculate the limit of error on inventory difference, a number of advanced statistical techniques are reviewed. The rest of the section deals with some regulatory aspects of data collection and analysis, for accountability purposes, and with the overall effectiveness of accountability in detecting diversion attempts in fuel fabrication facilities. A specific example of application of the accountability methods to a model fuel fabrication facility is given. The effect of random and systematic errors on the total material uncertainty has been discussed, together with the effect on uncertainty of the length of the accounting period.
9. Wisconsin Elementary and Secondary School Accounting System Handbook.
Science.gov (United States)
Nelson, C. Richard
This handbook is the basic accounting document for Wisconsin's public school systems; it presents the means to achieve uniformity in reporting on the efficacy of the Wisconsin Elementary and Secondary School Accounting System (WESSAS). Its purpose is to provide financial information that will promote reporting, auditing, interdistrict comparison,…
10. College Bibliocentre Acquisition and Accounting System Description Manual.
Science.gov (United States)
College Bibliocentre, Don Mills (Ontario).
The Acquisition and Accounting System is a complex designed to perform all functions in the following areas: (1) ordering; (2) receipt, shipment and cancellation; (3) accounts payable, (4) invoicing, (5) order status, (6) inventory, (7) college budgeting and (8) management information reports. Some of the benefits that accrue from the system are:…
11. Materials accounting in a fast-breeder-reactor fuels-reprocessing facility: optimal allocation of measurement uncertainties
Energy Technology Data Exchange (ETDEWEB)
Dayem, H.A.; Ostenak, C.A.; Gutmacher, R.G.; Kern, E.A.; Markin, J.T.; Martinez, D.P.; Thomas, C.C. Jr.
1982-07-01
This report describes the conceptual design of a materials accounting system for the feed preparation and chemical separations processes of a fast breeder reactor spent-fuel reprocessing facility. For the proposed accounting system, optimization techniques are used to calculate instrument measurement uncertainties that meet four different accounting performance goals while minimizing the total development cost of instrument systems. We identify instruments that require development to meet performance goals and measurement uncertainty components that dominate the materials balance variance. Materials accounting in the feed preparation process is complicated by large in-process inventories and spent-fuel assembly inputs that are difficult to measure. To meet 8 kg of plutonium abrupt and 40 kg of plutonium protracted loss-detection goals, materials accounting in the chemical separations process requires: process tank volume and concentration measurements having a precision less than or equal to 1%; accountability and plutonium sample tank volume measurements having a precision less than or equal to 0.3%, a shortterm correlated error less than or equal to 0.04%, and a long-term correlated error less than or equal to 0.04%; and accountability and plutonium sample tank concentration measurements having a precision less than or equal to 0.4%, a short-term correlated error less than or equal to 0.1%, and a long-term correlated error less than or equal to 0.05%. The effects of process design on materials accounting are identified. Major areas of concern include the voloxidizer, the continuous dissolver, and the accountability tank.
12. Materials accounting in a fast-breeder-reactor fuels-reprocessing facility: optimal allocation of measurement uncertainties
Energy Technology Data Exchange (ETDEWEB)
Dayem, H.A.; Ostenak, C.A.; Gutmacher, R.G.; Kern, E.A.; Markin, J.T.; Martinez, D.P.; Thomas, C.C. Jr.
1982-07-01
This report describes the conceptual design of a materials accounting system for the feed preparation and chemical separations processes of a fast breeder reactor spent-fuel reprocessing facility. For the proposed accounting system, optimization techniques are used to calculate instrument measurement uncertainties that meet four different accounting performance goals while minimizing the total development cost of instrument systems. We identify instruments that require development to meet performance goals and measurement uncertainty components that dominate the materials balance variance. Materials accounting in the feed preparation process is complicated by large in-process inventories and spent-fuel assembly inputs that are difficult to measure. To meet 8 kg of plutonium abrupt and 40 kg of plutonium protracted loss-detection goals, materials accounting in the chemical separations process requires: process tank volume and concentration measurements having a precision less than or equal to 1%; accountability and plutonium sample tank volume measurements having a precision less than or equal to 0.3%, a shortterm correlated error less than or equal to 0.04%, and a long-term correlated error less than or equal to 0.04%; and accountability and plutonium sample tank concentration measurements having a precision less than or equal to 0.4%, a short-term correlated error less than or equal to 0.1%, and a long-term correlated error less than or equal to 0.05%. The effects of process design on materials accounting are identified. Major areas of concern include the voloxidizer, the continuous dissolver, and the accountability tank.
13. The Accounting Network: How Financial Institutions React to Systemic Crisis.
Science.gov (United States)
Puliga, Michelangelo; Flori, Andrea; Pappalardo, Giuseppe; Chessa, Alessandro; Pammolli, Fabio
2016-01-01
The role of Network Theory in the study of the financial crisis has been widely spotted in the latest years. It has been shown how the network topology and the dynamics running on top of it can trigger the outbreak of large systemic crisis. Following this methodological perspective we introduce here the Accounting Network, i.e. the network we can extract through vector similarities techniques from companies' financial statements. We build the Accounting Network on a large database of worldwide banks in the period 2001-2013, covering the onset of the global financial crisis of mid-2007. After a careful data cleaning, we apply a quality check in the construction of the network, introducing a parameter (the Quality Ratio) capable of trading off the size of the sample (coverage) and the representativeness of the financial statements (accuracy). We compute several basic network statistics and check, with the Louvain community detection algorithm, for emerging communities of banks. Remarkably enough sensible regional aggregations show up with the Japanese and the US clusters dominating the community structure, although the presence of a geographically mixed community points to a gradual convergence of banks into similar supranational practices. Finally, a Principal Component Analysis procedure reveals the main economic components that influence communities' heterogeneity. Even using the most basic vector similarity hypotheses on the composition of the financial statements, the signature of the financial crisis clearly arises across the years around 2008. We finally discuss how the Accounting Networks can be improved to reflect the best practices in the financial statement analysis.
14. The Accounting Network: How Financial Institutions React to Systemic Crisis
Science.gov (United States)
Puliga, Michelangelo; Flori, Andrea; Pappalardo, Giuseppe; Chessa, Alessandro; Pammolli, Fabio
2016-01-01
The role of Network Theory in the study of the financial crisis has been widely spotted in the latest years. It has been shown how the network topology and the dynamics running on top of it can trigger the outbreak of large systemic crisis. Following this methodological perspective we introduce here the Accounting Network, i.e. the network we can extract through vector similarities techniques from companies’ financial statements. We build the Accounting Network on a large database of worldwide banks in the period 2001–2013, covering the onset of the global financial crisis of mid-2007. After a careful data cleaning, we apply a quality check in the construction of the network, introducing a parameter (the Quality Ratio) capable of trading off the size of the sample (coverage) and the representativeness of the financial statements (accuracy). We compute several basic network statistics and check, with the Louvain community detection algorithm, for emerging communities of banks. Remarkably enough sensible regional aggregations show up with the Japanese and the US clusters dominating the community structure, although the presence of a geographically mixed community points to a gradual convergence of banks into similar supranational practices. Finally, a Principal Component Analysis procedure reveals the main economic components that influence communities’ heterogeneity. Even using the most basic vector similarity hypotheses on the composition of the financial statements, the signature of the financial crisis clearly arises across the years around 2008. We finally discuss how the Accounting Networks can be improved to reflect the best practices in the financial statement analysis. PMID:27736865
15. Dynamics of Information Systems
CERN Document Server
Hirsch, Michael J; Murphey, Robert
2010-01-01
Our understanding of information and information dynamics has outgrown classical information theory. This book presents the research explaining the importance of information in the evolution of a distributed or networked system. It presents techniques for measuring the value or significance of information within the context of a system
16. Dynamic Systems Modeling
Directory of Open Access Journals (Sweden)
Sorin Dan ŞANDOR
2003-01-01
Full Text Available System Dynamics was introduced by Jay W. Forrester in the 1960s. Since then the methodology was adopted in many areas of natural or social sciences. This article tries to present briefly how this methodology works, both as Systems Thinking and as Modelling with Vensim computer software.
17. Semipredictable dynamical systems
Science.gov (United States)
2016-10-01
A new class of deterministic dynamical systems, termed semipredictable dynamical systems, is presented. The spatiotemporal evolution of these systems have both predictable and unpredictable traits, as found in natural complex systems. We prove a general result: The dynamics of any deterministic nonlinear cellular automaton (CA) with p possible dynamical states can be decomposed at each instant of time in a superposition of N layers involving p0, p1, …, pN - 1 dynamical states each, where the pk ∈ N , k ∈ [ 0 , N - 1 ] are divisors of p. If the divisors coincide with the prime factors of p this decomposition is unique. Conversely, we also prove that N CA working on symbols p0, p1, …, pN - 1 can be composed to create a graded CA rule with N different layers. We then show that, even when the full spatiotemporal evolution can be unpredictable, certain traits (layers) can exactly be predicted. We present explicit examples of such systems involving compositions of Wolfram's 256 elementary CA and a more complex CA rule acting on a neighborhood of two sites and 12 symbols and whose rule table corresponds to the smallest Moufang loop M12(S3, 2).
18. New Computer Account Management System on 22 November
CERN Multimedia
IT Department
2010-01-01
On 22 November, the current management system called CRA was replaced by a new self-service tool available on a Web Portal. The End-Users can now manage their computer accounts and resources themselves through this Web Portal. The ServiceDesk will provide help or forward requests to the appropriate support line in case of specific requests. Account management tools The Account Management Portal allows you to: Manage your primary account; Change your password; Create and manage secondary and service accounts; Manage application and resource authorizations and settings; Find help and documentation concerning accounts and resources. Get Help In the event of any questions or problems, please contact the ServiceDesk (phone +41 22 767 8888 or [email protected]) The Account Management Team
19. ANALYSIS OF THE ACCOUNTING SYSTEMS FROM ROMANIA AND MOLDOVA
Directory of Open Access Journals (Sweden)
Lucia\tMOROSAN‐DĂNILĂ
2015-06-01
Full Text Available Over the centuries, different countries have met their accounting systems adjusted to the economic, social and political. However, at the end of the twentieth century, it was possible to distinguish several “families” of accounting, without the researchers to reach agreement on a definitive classification of accounting systems practiced in the world. The diversity of national accounting systems put, obviously, some problems. It is, indeed, difficult to compare the financial statements of companies in different countries, which apply their national rules. With the interconnection of national economies and the growth of large financial markets at the end of the last century, these issues have gained greater acuity. It is necessary that investors can compare financial performance of firms of different nationalities. This article is trying to present and analyse the accounting systems of two neighbour countries, Romania and Moldova, in order to understand the possibility of a multinational investment.
20. Dynamic system classifier
CERN Document Server
Pumpe, Daniel; Müller, Ewald; Enßlin, Torsten A
2016-01-01
Stochastic differential equations describe well many physical, biological and sociological systems, despite the simplification often made in their derivation. Here the usage of simple stochastic differential equations to characterize and classify complex dynamical systems is proposed within a Bayesian framework. To this end, we develop a dynamic system classifier (DSC). The DSC first abstracts training data of a system in terms of time dependent coefficients of the descriptive stochastic differential equation. Thereby the DSC identifies unique correlation structures within the training data. For definiteness we restrict the presentation of DSC to oscillation processes with a time dependent frequency {\\omega}(t) and damping factor {\\gamma}(t). Although real systems might be more complex, this simple oscillator captures many characteristic features. The {\\omega} and {\\gamma} timelines represent the abstract system characterization and permit the construction of efficient signal classifiers. Numerical experiment...
1. Dynamic system classifier
Science.gov (United States)
Pumpe, Daniel; Greiner, Maksim; Müller, Ewald; Enßlin, Torsten A.
2016-07-01
Stochastic differential equations describe well many physical, biological, and sociological systems, despite the simplification often made in their derivation. Here the usage of simple stochastic differential equations to characterize and classify complex dynamical systems is proposed within a Bayesian framework. To this end, we develop a dynamic system classifier (DSC). The DSC first abstracts training data of a system in terms of time-dependent coefficients of the descriptive stochastic differential equation. Thereby the DSC identifies unique correlation structures within the training data. For definiteness we restrict the presentation of the DSC to oscillation processes with a time-dependent frequency ω (t ) and damping factor γ (t ) . Although real systems might be more complex, this simple oscillator captures many characteristic features. The ω and γ time lines represent the abstract system characterization and permit the construction of efficient signal classifiers. Numerical experiments show that such classifiers perform well even in the low signal-to-noise regime.
2. Depository Accounting of Securities in the Ukrainian Stock Market Regulation System
OpenAIRE
Veriha Hanna V.
2016-01-01
The aim of the article is to study the procedures, technologies, prudential regulation of depository accounting of securities in the system of the Ukrainian stock market infrastructure and identify directions of its improvement. The article analyzes the dynamics of the number of licenses issued by types of professional activity in the stock market. The necessity for further improvement of mechanisms of the updated system of depository accounting of securities in Ukraine has ...
3. Complexity in Dynamical Systems
Science.gov (United States)
Moore, Cristopher David
The study of chaos has shown us that deterministic systems can have a kind of unpredictability, based on a limited knowledge of their initial conditions; after a finite time, the motion appears essentially random. This observation has inspired a general interest in the subject of unpredictability, and more generally, complexity; how can we characterize how "complex" a dynamical system is?. In this thesis, we attempt to answer this question with a paradigm of complexity that comes from computer science, we extract sets of symbol sequences, or languages, from a dynamical system using standard methods of symbolic dynamics; we then ask what kinds of grammars or automata are needed a generate these languages. This places them in the Chomsky heirarchy, which in turn tells us something about how subtle and complex the dynamical system's behavior is. This gives us insight into the question of unpredictability, since these automata can also be thought of as computers attempting to predict the system. In the culmination of the thesis, we find a class of smooth, two-dimensional maps which are equivalent to the highest class in the Chomsky heirarchy, the turning machine; they are capable of universal computation. Therefore, these systems possess a kind of unpredictability qualitatively different from the usual "chaos": even if the initial conditions are known exactly, questions about the system's long-term dynamics are undecidable. No algorithm exists to answer them. Although this kind of unpredictability has been discussed in the context of distributed, many-degree-of -freedom systems (for instance, cellular automata) we believe this is the first example of such phenomena in a smooth, finite-degree-of-freedom system.
4. Sandia Dynamic Materials Program Strategic Plan.
Energy Technology Data Exchange (ETDEWEB)
Flicker, Dawn Gustine [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Benage, John F. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Desjarlais, Michael P. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Knudson, Marcus D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Leifeste, Gordon T. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lemke, Raymond W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Mattsson, Thomas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wise, Jack L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2017-05-01
Materials in nuclear and conventional weapons can reach multi-megabar pressures and 1000s of degree temperatures on timescales ranging from microseconds to nanoseconds. Understanding the response of complex materials under these conditions is important for designing and assessing changes to nuclear weapons. In the next few decades, a major concern will be evaluating the behavior of aging materials and remanufactured components. The science to enable the program to underwrite decisions quickly and confidently on use, remanufacturing, and replacement of these materials will be critical to NNSA’s new Stockpile Responsiveness Program. Material response is also important for assessing the risks posed by adversaries or proliferants. Dynamic materials research, which refers to the use of high-speed experiments to produce extreme conditions in matter, is an important part of NNSA’s Stockpile Stewardship Program.
5. Complexified dynamical systems
Energy Technology Data Exchange (ETDEWEB)
Bender, Carl M [Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Holm, Darryl D [Department of Mathematics, Imperial College, London SW7 2AZ (United Kingdom); Hook, Daniel W [Blackest Laboratory, Imperial College, London SW7 2BZ (United Kingdom)
2007-08-10
Many dynamical systems, such as the Lotka-Volterra predator-prey model and the Euler equations for the free rotation of a rigid body, are PT symmetric. The standard and well-known real solutions to such dynamical systems constitute an infinitessimal subclass of the full set of complex solutions. This paper examines a subset of the complex solutions that contains the real solutions, namely those having PT symmetry. The condition of PT symmetry selects out complex solutions that are periodic. (fast track communication)
6. ACCOUNTING - A SOURCE OF INFORMATION WITHIN THE MANAGEMENT SYSTEM
Directory of Open Access Journals (Sweden)
BUŞAN GABRIELA
2014-05-01
Full Text Available Accounting information system is a complex system of registration and processing of goods movement, the reflection of the rights and obligations with economic value; it is necessary and indispensable to the economy. Through its own system of concepts and procedures, accounting is the only discipline that can provide information that form the basis of the assessment of an organization by a wide category of users. Those in need of information for the purpose of making accounting decisions on allocating economic resources efficiently and effectively.
7. System dynamics with interaction discontinuity
CERN Document Server
Luo, Albert C J
2015-01-01
This book describes system dynamics with discontinuity caused by system interactions and presents the theory of flow singularity and switchability at the boundary in discontinuous dynamical systems. Based on such a theory, the authors address dynamics and motion mechanism of engineering discontinuous systems due to interaction. Stability and bifurcations of fixed points in nonlinear discrete dynamical systems are presented, and mapping dynamics are developed for analytical predictions of periodic motions in engineering discontinuous dynamical systems. Ultimately, the book provides an alternative way to discuss the periodic and chaotic behaviors in discontinuous dynamical systems.
CERN Document Server
Cherne, Frank J; Zhernokletov, Mikhail V; Glushak, B L; Zocher, Marvin A
2007-01-01
Understanding the physical and thermomechanical response of materials subjected to intensive dynamic loading is a challenge of great significance in engineering today. This volume assumes the task of gathering both experimental and diagnostic methods in one place, since not much information has been previously disseminated in the scientific literature.
9. Experiments showing dynamics of materials interfaces
Energy Technology Data Exchange (ETDEWEB)
Benjamin, R.F. [Los Alamos National Lab., NM (United States). Dynamic Experimentation Div.
1997-02-01
The discipline of materials science and engineering often involves understanding and controlling properties of interfaces. The authors address the challenge of educating students about properties of interfaces, particularly dynamic properties and effects of unstable interfaces. A series of simple, inexpensive, hands-on activities about fluid interfaces provides students with a testbed to develop intuition about interface dynamics. The experiments highlight the essential role of initial interfacial perturbations in determining the dynamic response of the interface. The experiments produce dramatic, unexpected effects when initial perturbations are controlled and inhibited. These activities help students to develop insight about unstable interfaces that can be applied to analogous problems in materials science and engineering. The lessons examine Rayleigh-Taylor instability, an interfacial instability that occurs when a higher-density fluid is above a lower-density fluid.
10. Dynamics and Controls in Maglev Systems
Science.gov (United States)
1992-09-01
and Alscher, H. 1986. "The Magnetic Train Transrapid 06," Proc. Int. Conf. Maglev and Linear Drives, May 14-16, 1986, Vancouver, B.C., Canada, Publ. by...AD-A263 087 ANL-92/43It Il~l Iif IIt[11 Materials and Components Dynamics and Controls Technology Division Materials and Components in Maglev ...Argonne, Illinois 60439 Distribution Category: All Transportation Systems Reports (UC-330) Dynamics and Controls in Maglev Systems by Y. Cai and S. S
11. Accounting, charging and billing for dynamic service composition chains
NARCIS (Netherlands)
Rumph, F.J.; Kruithof, G.H.; Huitema, G.B.
2010-01-01
Services delivered to an end user can be composed of numerous subservices and form chains of composed services. These service composition chains traditionally consist of a static set of business entities. However, in order to increase business agility, dynamic service composition chains can be used
12. Designing Biomimetic, Dissipative Material Systems
Energy Technology Data Exchange (ETDEWEB)
Balazs, Anna C. [Univ. of Pittsburgh, PA (United States). Chemical Engineering Dept.; Whitesides, George M. [Harvard Univ., Cambridge, MA (United States). Dept. of Chemistry and Chemical Biology; Brinker, C. Jeffrey [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Chemical and Nuclear Engineering. Dept. of Chemistry. Dept. of Molecular Genetics and Microbiology. Center for Micro-Engineered Materials; Aranson, Igor S. [UChicago, LLC., Argonne, IL (United States); Chaikin, Paul [New York Univ. (NYU), NY (United States). Dept. of Physics; Dogic, Zvonimir [Brandeis Univ., Waltham, MA (United States). Dept. of Physics; Glotzer, Sharon [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Chemical Engineering. Dept. of Materials Science and Engineering. Dept. of Macromolecular Science and Engineering Physics; Hammer, Daniel [Univ. of Pennsylvania, Philadelphia, PA (United States). School of Engineering and Applied Science; Irvine, Darrell [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Dept. of Materials Science and Engineering and Biological Engineering; Little, Steven R. [Univ. of Pittsburgh, PA (United States). Chemical Engineering Dept.; Olvera de la Cruz, Monica [Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science and Engineering; Parikh, Atul N. [Univ. of California, Davis, CA (United States). Dept. of Biomedical Engineering. Dept. of Chemical Engineering and Materials Science; Stupp, Samuel [Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science and Engineering. Dept. of Chemistry. Dept. of Medicine. Dept. of Biomedical Engineering; Szostak, Jack [Harvard Univ., Cambridge, MA (United States). Dept. of Chemistry and Chemical Biology
2016-01-21
Throughout human history, new materials have been the foundation of transformative technologies: from bronze, paper, and ceramics to steel, silicon, and polymers, each material has enabled far-reaching advances. Today, another new class of materials is emerging—one with both the potential to provide radically new functions and to challenge our notion of what constitutes a “material”. These materials would harvest, transduce, or dissipate energy to perform autonomous, dynamic functions that mimic the behaviors of living organisms. Herein, we discuss the challenges and benefits of creating “dissipative” materials that can potentially blur the boundaries between living and non-living matter.
13. An accounting system to support process improvements: Transition to lean accounting
Directory of Open Access Journals (Sweden)
Patxi Ruiz de Arbulo-López
2010-12-01
Full Text Available From the last two decades of the 20th Century on, many companies have adopted production strategies that could be termed “lean manufacturing”. Lean team leaders state that traditional costing systems fail to properly assess their operational improvements and therefore ask for new cost accounting methods. The search for a new accounting paradigm has led to important applied research and several accounting methods. In this paper we are going to show the state of the art in costing techniques used in companies that adopt lean manufacturing practices and we will be presenting an additional costing method, based on Activity-Based Costing, intended to cast light on the operational improvements achieved in companies that are just starting a maturity path towards lean manufacturing. This article examines how the approach is applied in the context of a manufacturing company.
14. Accounting Systems in Small and Micro Enterprises in Kenya ...
African Journals Online (AJOL)
Accounting Systems in Small and Micro Enterprises in Kenya. ... PROMOTING ACCESS TO AFRICAN RESEARCH ... means to small and micro traders in Kenya, by reviewing the practices and principles they use in running their businesses.
15. Design and Analysis: Payroll of Accounting Information System
Directory of Open Access Journals (Sweden)
Suryanto Suryanto
2011-05-01
Full Text Available Purpose of the research are to analyze, design, and recommended the payroll of accounting information system that support the internal control to solve the problem. Research methods used are book studies, field studies, and design studies. Fields studies done by survey and interview. The expected result are to give a review about the payroll of accounting information system in the ongoing business process of company and to solve all the weakness in the payroll system, so the company can use the integrated information system in counting of the payroll. Conclusion that can take from the research are there’s some manipulation risk of attendance data and documentation of form still using a manual system and simple data backup. Then, there’s also manipulation risk in allowance cash system and all the report that include in the payroll.Index Terms - Accounting Information System, Payroll
16. PLASTICITY OF SELECTED METALLIC MATERIALS IN DYNAMIC DEFORMATION CONDITIONS
OpenAIRE
2014-01-01
Characteristics of a modernized flywheel machine has been presented in the paper. The laboratory stand enables to perform dynamic tensile tests and impact bending with a linear velocity of the enforcing element in the range of 5÷40 m/s. A new data acquisition system, based on the tensometric sensors, allows for significant qualitative improvement of registered signals. Some preliminary dynamic forming tests were performed for the selected group of metallic materials. Subsequent microstruct...
17. Expert System Models in the Companies' Financial and Accounting Domain
CERN Document Server
Mates, D; Bostan, I; Grosu, V
2010-01-01
The present paper is based on studying, analyzing and implementing the expert systems in the financial and accounting domain of the companies, describing the use method of the informational systems that can be used in the multi-national companies, public interest institutions, and medium and small dimension economical entities, in order to optimize the managerial decisions and render efficient the financial-accounting functionality. The purpose of this paper is aimed to identifying the economical exigencies of the entities, based on the already used accounting instruments and the management software that could consent the control of the economical processes and patrimonial assets.
18. Patient Accounting Systems: Are They Fit with the Users' Requirements?
Science.gov (United States)
Ayatollahi, Haleh; Nazemi, Zahra; Haghani, Hamid
2016-01-01
A patient accounting system is a subsystem of a hospital information system. This system like other information systems should be carefully designed to be able to meet users' requirements. The main aim of this research was to investigate users' requirements and to determine whether current patient accounting systems meet users' needs or not. This was a survey study, and the participants were the users of six patient accounting systems used in 24 teaching hospitals. A stratified sampling method was used to select the participants (n = 216). The research instruments were a questionnaire and a checklist. The mean value of ≥3 showed the importance of each data element and the capability of the system. Generally, the findings showed that the current patient accounting systems had some weaknesses and were able to meet between 70% and 80% of users' requirements. The current patient accounting systems need to be improved to be able to meet users' requirements. This approach can also help to provide hospitals with more usable and reliable financial information.
19. Network dynamics and systems biology
Science.gov (United States)
Norrell, Johannes A.
transition point, called critical, exhibit many of the features of regulatory networks, and recent studies suggest that some specific regulatory networks are indeed near-critical. We ask whether certain statistical measures of the ensemble behavior of large continuous networks are reproduced by Boolean models. We find that, in spite of the lack of correspondence between attractors observed in smaller systems, the statistical characterization given by the continuous and Boolean models show close agreement, and the transition between order and disorder known in Boolean systems can occur in continuous systems as well. One effect that is not present in Boolean systems, the failure of information to propagate down chains of elements of arbitrary length, is present in a class of continuous networks. In these systems, a modified Boolean theory that takes into account the collective effect of propagation failure on chains throughout the network gives a good description of the observed behavior. We find that propagation failure pushes the system toward greater order, resulting in a partial or complete suppression of the disordered phase. Finally, we explore a dynamical process of direct biological relevance: asymmetric cell division in A. thaliana. The long term goal is to develop a model for the process that accurately accounts for both wild type and mutant behavior. To contribute to this endeavor, we use confocal microscopy to image roots in a SHORT-ROOT inducible mutant. We compute correlation functions between the locations of asymmetrically divided cells, and we construct stochastic models based on a few simple assumptions that accurately predict the non-zero correlations. Our result shows that intracellular processes alone cannot be responsible for the observed divisions, and that an intercell signaling mechanism could account for the measured correlations.
20. Training in Mechanized Stock Accounting Systems in Army Logistics.
Science.gov (United States)
Leedy, Herbert B.
Army experience with a small mechanized stock accounting system, the NCR 500, was studied with respect to personnel and training, in order to improve implementation of newer and more complex computer-based logistics systems. Officers and enlisted personnel in various duty positions connected with NCR 500 systems in four Far Eastern commands were…
1. Control Systems in Accounting; Business Education: 7709.21.
Science.gov (United States)
McGahee, Bobby; Carino, Mariano
The course prepares the business education student to maintain voucher systems, inventory and budgetary controls, including notes, drafts, and business taxes. The student should have attained the objectives of Partnership Accounting prior to enrollment. Course content includes equipment and supplies, the voucher system, inventory control systems,…
2. Lunar Materials Handling System Project
Data.gov (United States)
National Aeronautics and Space Administration — The Lunar Materials Handling System (LMHS) is a method for transfer of bulk materials and products into and out of process equipment in support of lunar and Mars in...
3. Multistability in dynamical systems
CERN Document Server
Mendes, R V
1999-01-01
In neuroscience, optics and condensed matter there is ample physical evidence for multistable dynamical systems, that is, systems with a large number of attractors. The known mathematical mechanisms that lead to multiple attractors are homoclinic tangencies and stabilization, by small perturbations or by coupling, of systems possessing a large number of unstable invariant sets. A short review of the existent results is presented, as well as two new results concerning the existence of a large number of stable periodic orbits in a perturbed marginally stable dissipative map and an infinite number of such orbits in two coupled quadratic maps working on the Feigenbaum accumulation point.
4. Materials measurement and accounting in an operating plutonium conversion and purification process. Phase I. Process modeling and simulation. [PUCSF code
Energy Technology Data Exchange (ETDEWEB)
Thomas, C.C. Jr.; Ostenak, C.A.; Gutmacher, R.G.; Dayem, H.A.; Kern, E.A.
1981-04-01
A model of an operating conversion and purification process for the production of reactor-grade plutonium dioxide was developed as the first component in the design and evaluation of a nuclear materials measurement and accountability system. The model accurately simulates process operation and can be used to identify process problems and to predict the effect of process modifications.
5. Interactive Dynamic-System Simulation
CERN Document Server
Korn, Granino A
2010-01-01
Showing you how to use personal computers for modeling and simulation, Interactive Dynamic-System Simulation, Second Edition provides a practical tutorial on interactive dynamic-system modeling and simulation. It discusses how to effectively simulate dynamical systems, such as aerospace vehicles, power plants, chemical processes, control systems, and physiological systems. Written by a pioneer in simulation, the book introduces dynamic-system models and explains how software for solving differential equations works. After demonstrating real simulation programs with simple examples, the author
6. Material control system simulator user's manual
Energy Technology Data Exchange (ETDEWEB)
Hollstien, R.B.
1978-01-24
This report describes the use of a Material Control System Simulator (MCSS) program for determination of material accounting uncertainty and system response to particular adversary action sequences that constitute plausible material diversion attempts. The program is intended for use in situations where randomness, uncertainty, or interaction of adversary actions and material control system components make it difficult to assess safeguards effectiveness against particular material diversion attempts.
7. Methodology of Adaptive Integrated Accounting System in Information Environment
Directory of Open Access Journals (Sweden)
Bochulya Tetyana V.
2013-12-01
Full Text Available The goal of the article lies in the study of logical and methodological justification of formation of the integrated system of accounting based on realities of the co-ordinated transformation of the society and economy and development of a new knowledge about formation and adjustment of the accounting system in it’s a priori new information competence with expansion of functionality for the justified idea of existence and development of business. Taking developments of the best representatives of the leading scientific society as a basis, the article offers a new vision of organisation of the accounting system, based on the modern projection of information competence and harmonisation of main processes of information service for adaptation of the system for multi-vector inquiries of consumers of information. Pursuant to results of the conducted study, the article makes an effort to change the established opinion about information and professional competences of the accounting system and attach a new qualitative significance to them. The article makes a proposal with respect to calculation of quality of the information system on the basis of key indicators of its information service. It lays the foundation of the prospective study of the problems of building the accounting system in such a projection, so that realities of internal and external processes were maximally co-ordinated based on the idea of their information development.
8. Diligence of Domain Engineering in Accounting Management System
Directory of Open Access Journals (Sweden)
Mukesh Arya
2012-07-01
Full Text Available This paper presents on domain feature modeling, domain architecture design and domain implementation in an enterprise. This paper demonstrates the accounting management feature modeling based on the extended (Feature-Oriented Domain Analysis FODA method and system architecture of accounting management domain, integrates Aspect Object Oriented Programming technology with domain implementation, and designs a whippersnapper AOP framework based on the object proxy pattern to separates crosscutting concerns in the domain implementation phrase. Research result shows this method can effectively seal insulate and abstract variability in requirements of accounting management domain, instruct the designing and implementation of accounting management components, get the requirement of software reuse, resource sharing and collaboration in accounting management domain.
9. Optical dynamic deformation measurements at translucent materials.
Science.gov (United States)
Philipp, Katrin; Koukourakis, Nektarios; Kuschmierz, Robert; Leithold, Christoph; Fischer, Andreas; Czarske, Jürgen
2015-02-15
Due to their high stiffness-to-weight ratio, glass fiber-reinforced polymers are an attractive material for rotors, e.g., in the aerospace industry. A fundamental understanding of the material behavior requires non-contact, in-situ dynamic deformation measurements. The high surface speeds and particularly the translucence of the material limit the usability of conventional optical measurement techniques. We demonstrate that the laser Doppler distance sensor provides a powerful and reliable tool for monitoring radial expansion at fast rotating translucent materials. We find that backscattering in material volume does not lead to secondary signals as surface scattering results in degradation of the measurement volume inside the translucent medium. This ensures that the acquired signal contains information of the rotor surface only, as long as the sample surface is rough enough. Dynamic deformation measurements of fast-rotating fiber-reinforced polymer composite rotors with surface speeds of more than 300 m/s underline the potential of the laser Doppler sensor.
10. A mathematical model of sentimental dynamics accounting for marital dissolution.
Directory of Open Access Journals (Sweden)
José-Manuel Rey
Full Text Available BACKGROUND: Marital dissolution is ubiquitous in western societies. It poses major scientific and sociological problems both in theoretical and therapeutic terms. Scholars and therapists agree on the existence of a sort of second law of thermodynamics for sentimental relationships. Effort is required to sustain them. Love is not enough. METHODOLOGY/PRINCIPAL FINDINGS: Building on a simple version of the second law we use optimal control theory as a novel approach to model sentimental dynamics. Our analysis is consistent with sociological data. We show that, when both partners have similar emotional attributes, there is an optimal effort policy yielding a durable happy union. This policy is prey to structural destabilization resulting from a combination of two factors: there is an effort gap because the optimal policy always entails discomfort and there is a tendency to lower effort to non-sustaining levels due to the instability of the dynamics. CONCLUSIONS/SIGNIFICANCE: These mathematical facts implied by the model unveil an underlying mechanism that may explain couple disruption in real scenarios. Within this framework the apparent paradox that a union consistently planned to last forever will probably break up is explained as a mechanistic consequence of the second law.
11. Estimation of hygroscopic of electrotechnical materials by dynamic speckle technique
OpenAIRE
Bertolini, Guillermo Ramón; Cabello, Carmen Inés; Arizaga, R.; Trivi, Marcelo Ricardo; Barbera, Gustavo Ariel
2013-01-01
Dynamic speckle laser (DLS) technique has been applied to the analysis of different biological systems, inorganic materials and industrial processes. In this paper, we use this technique to analyze the hygroscopic properties of different types of porcelain and papers for electrotechnical purposes. Experimental speckle results showed different behavior depending on physicochemical and textural properties of the samples.
12. Principles and methods of managerial cost-accounting systems.
Science.gov (United States)
Suver, J D; Cooper, J C
1988-01-01
An introduction to cost-accounting systems for pharmacy managers is provided; terms are defined and examples of specific applications are given. Cost-accounting systems determine, record, and report the resources consumed in providing services. An effective cost-accounting system must provide the information needed for both internal and external reports. In accounting terms, cost is the value given up to secure an asset. In determining how volumes of activity affect costs, fixed costs and variable costs are calculated; applications include pricing strategies, cost determinations, and break-even analysis. Also discussed are the concepts of direct and indirect costs, opportunity costs, and incremental and sunk costs. For most pharmacy department services, process costing, an accounting of intermediate outputs and homogeneous units, is used; in determining the full cost of providing a product or service (e.g., patient stay), job-order costing is used. Development of work-performance standards is necessary for monitoring productivity and determining product costs. In allocating pharmacy department costs, a ratio of costs to charges can be used; this method is convenient, but microcosting (specific identification of the costs of products) is more accurate. Pharmacy managers can use cost-accounting systems to evaluate the pharmacy's strategies, policies, and services and to improve budgets and reports.
13. Stationary dynamical systems
CERN Document Server
Furstenberg, Hillel
2009-01-01
Following works of Furstenberg and Nevo and Zimmer we present an outline of a theory of stationary (or m-stationary) dynamical systems for a general acting group G equipped with a probability measure m. Our purpose is two-fold: First to suggest a more abstract line of development, including a simple structure theory. Second, to point out some interesting applications; one of these is a Szemeredi type theorem for SL(2,R).
14. New Valences for the Financial-Accounting System
Directory of Open Access Journals (Sweden)
2009-01-01
Full Text Available A new approach to a company’s information systems is needed, if wetake into consideration the globalization process of the economy, the intensifiedcompetition, the impose of new qualitative demands or the adjustment to newaccounting standards. The former accountant is about to be replaced by the„professional employee with accounting information”, who knows very wellhow to use the domain technologies. The need for clear, correct and significantinformation has become a must for all the departments of a company and,definitely, this is especially the case for the financial-accounting department,i.e. when we have to come up with solutions for the profitability of thecompany.
15. Accretion Dynamics on Wet Granular Materials.
Science.gov (United States)
Saingier, Guillaume; Sauret, Alban; Jop, Pierre
2017-05-19
Wet granular aggregates are common precursors of construction materials, food, and health care products. The physical mechanisms involved in the mixing of dry grains with a wet substrate are not well understood and difficult to control. Here, we study experimentally the accretion of dry grains on a wet granular substrate by measuring the growth dynamics of the wet aggregate. We show that this aggregate is fully saturated and its cohesion is ensured by the capillary depression at the air-liquid interface. The growth dynamics is controlled by the liquid fraction at the surface of the aggregate and exhibits two regimes. In the viscous regime, the growth dynamics is limited by the capillary-driven flow of liquid through the granular packing to the surface of the aggregate. In the capture regime, the capture probability depends on the availability of the liquid at the saturated interface, which is controlled by the hydrostatic depression in the material. We propose a model that rationalizes our observations and captures both dynamics based on the evolution of the capture probability with the hydrostatic depression.
16. Dynamical systems theory for music dynamics
CERN Document Server
Boon, J P
1994-01-01
Abstract:We show that, when music pieces are cast in the form of time series of pitch variations, the concepts and tools of dynamical systems theory can be applied to the analysis of {\\it temporal dynamics} in music. (i) Phase space portraits are constructed from the time series wherefrom the dimensionality is evaluated as a measure of the {\\pit global} dynamics of each piece. (ii) Spectral analysis of the time series yields power spectra (\\sim f^{-\
17. ACCOUNTING AS THE MAJOR INFORMATION SYSTEM IN CONDITIONS OF GLOBALIZATION
Directory of Open Access Journals (Sweden)
V.I. Efimenkov
2006-03-01
Full Text Available In article intrinsic attributes of the information are analyzed, its role in a today's society is defined. Modern accounting is considered as information system in which by its nature information asymmetry is inherent. On a background of numerous examples of falsification of the data of accounting and the consequences connected to it attempt to define key aspects of its further development is made.
18. Accountability systems and instructional approaches in youth volleyball training.
Science.gov (United States)
Pereira, Felismina; Mesquita, Isabel; Graça, Amândio
2009-01-01
19. The perseverance of Pacioli's goods inventory accounting system
OpenAIRE
Stoner, G.
2011-01-01
This paper details sources of the 'undoubtedly strange' (Yamey, 1994a, p.119) system of goods inventory records described in Pacioli’s 1494 bookkeeping treatise and traces the longevity and widespread use of this early perpetual inventory recording (EPIR) system in English language texts. By doing so and contrasting this system with the bookkeeping treatment of modern texts, it is shown that the EPIR system persisted as the dominant form of goods inventory accounting for between 400 and 500 y...
20. Nuclear Material Accountability Applications of a Continuous Energy and Direction Gamma Ray Detector
Energy Technology Data Exchange (ETDEWEB)
David Gerts; Robert Bean; Marc Paff
2010-07-01
The Idaho National Laboratory has recently developed a detector system based on the principle of a Wilson cloud chamber that gives the original energy and direction to a gamma ray source. This detector has the properties that the energy resolution is continuous and the direction to the source can be resolved to desired fidelity. Furthermore, the detector has low power requirements, is durable, operates in widely varying environments, and is relatively cheap to produce. This detector is expected, however, to require significant time to perform measurements. To mitigate the significant time for measurements, the detector is expected to scale to very large sizes with a linear increase in cost. For example, the proof of principle detector is approximately 30,000 cm3. This work describes the technical results that lead to these assertions. Finally, the applications of this detector are described in the context of nuclear material accountability.
1. Kalman filtering naturally accounts for visually guided and predictive smooth pursuit dynamics.
Science.gov (United States)
Orban de Xivry, Jean-Jacques; Coppe, Sébastien; Blohm, Gunnar; Lefèvre, Philippe
2013-10-30
The brain makes use of noisy sensory inputs to produce eye, head, or arm motion. In most instances, the brain combines this sensory information with predictions about future events. Here, we propose that Kalman filtering can account for the dynamics of both visually guided and predictive motor behaviors within one simple unifying mechanism. Our model relies on two Kalman filters: (1) one processing visual information about retinal input; and (2) one maintaining a dynamic internal memory of target motion. The outputs of both Kalman filters are then combined in a statistically optimal manner, i.e., weighted with respect to their reliability. The model was tested on data from several smooth pursuit experiments and reproduced all major characteristics of visually guided and predictive smooth pursuit. This contrasts with the common belief that anticipatory pursuit, pursuit maintenance during target blanking, and zero-lag pursuit of sinusoidally moving targets all result from different control systems. This is the first instance of a model integrating all aspects of pursuit dynamics within one coherent and simple model and without switching between different parallel mechanisms. Our model suggests that the brain circuitry generating a pursuit command might be simpler than previously believed and only implement the functional equivalents of two Kalman filters whose outputs are optimally combined. It provides a general framework of how the brain can combine continuous sensory information with a dynamic internal memory and transform it into motor commands.
2. The Role of Politics and Governance in Educational Accountability Systems
Science.gov (United States)
Brewer, Dominic J.; Killeen, Kieran M.; Welsh, Richard O.
2013-01-01
This brief utilizes case study methodology to illustrate the role of governance in educational accountability systems. Most research on the effectiveness of such systems has focused on technical components, such as standards-setting, assessments, rewards and sanctions, and data collection and reporting. This brief seeks to demonstrate that this…
3. South Carolina Student Accountability System OSIRIS Instruction Manual.
Science.gov (United States)
South Carolina State Dept. of Education, Columbia.
This manual expresses the South Carolina State Department of Education's understanding of the new, computerized school administration system called OSIRIS and the policy regarding its use with the Student Accountability System (SAS). The SAS is a method used to obtain a cumulative headcount of students served in certain programs specified in the…
4. ACCOUNTABILITY SYSTEMS AND INSTRUCTIONAL APPROACHES IN YOUTH VOLLEYBALL TRAINING
Directory of Open Access Journals (Sweden)
Felismina Pereira
2009-09-01
5. Butschli Dynamic Droplet System
DEFF Research Database (Denmark)
Armstrong, R.; Hanczyc, M.
2013-01-01
of a technology with living properties. Otto Butschli first described the system in 1898, when he used alkaline water droplets in olive oil to initiate a saponification reaction. This simple recipe produced structures that moved and exhibited characteristics that resembled, at least superficially, the amoeba. We......Dynamical oil-water systems such as droplets display lifelike properties and may lend themselves to chemical programming to perform useful work, specifically with respect to the built environment. We present Butschli water-in-oil droplets as a model for further investigation into the development...... to the oil phase), qualify this system as an example of living technology. The analysis of the Butschli droplets suggests that a set of conditions may precede the emergence of lifelike characteristics and exemplifies the richness of this rudimentary chemical system, not only for artificial life...
6. New hose materials for dynamic loads
Energy Technology Data Exchange (ETDEWEB)
Schulz, P.; Weber, J.; Wohlfarth, L. [Volkswagen AG, Wolfsburg (Germany)
2001-07-01
Dynamically stressed hoses continue to represent a challenge in the various areas where they are used in the automobile. This is true not only as regards the selection of suitable hose materials but also the necessary reinforcement technology. This is due to increasing requirements for temperature and chemical resistance resulting from new and further developments in the field of engines and assemblies. In addition to the 'classic' hose materials with internal and external elastomeric layers in conjunction with reinforcing elements (for example, servo hose or brake hose materials), the beginning of the 1990s saw increasing interest on the part of the automotive industry in hose and pipe materials made of thermoplastic elastomers (for example, TEEE) in the fields of intake and crankcase ventilation as well as plastic / rubber composite concepts for hoses. These plastic / rubber composite designs in particular are to be regarded as tailor-made problem solutions for specific functional and environmental aspects (minimisation of the permeation / emission of liquid or gaseous substances) in conjunction with a dynamic load-bearing capacity. (orig.)
7. PREFACE: International Symposium on Dynamic Deformation and Fracture of Advanced Materials (D2FAM 2013)
Science.gov (United States)
2013-07-01
8. Determination of dynamic performance of freight cars taking into account technical condition of side bearers
Directory of Open Access Journals (Sweden)
S.Myamlin
2013-02-01
Full Text Available Purpose. The railway transport plays an important role in social and economic life of the country and carries out the large containment of transportation activities. The transport industry should migrate towards innovation changes and increase its significance as an important transit subsystem on the way of renovation of both the infrastructure and the strategy of all transportation process components including the interaction with other transport modes. At present the life sets strategic challenges for the railway branch, and the basic goals among them are as follows: high-speed train traffic development, increase of the weight of freight trains, new rolling stock development etc. Due to the urgency of this subject, the researchers should cope with the task devoted to one of aspects of improving the freight transportation efficiency, namely to the study of effects of various factors and characteristics of technical conditions of the freight cars running gears (which are unavoidable to arise during operation on their basic dynamic indices. The deviations of technical conditions of running gears from the normal state of the wedge system of bogie swing suspension also play an important role among them. The purpose of the paper is to investigate the influence of different factors of the technical conditions of freight car running gears (size deviation in both the bearers and the wedge system during operation on their basic indices – coefficients of horizontal and vertical dynamics, vehicle body acceleration, frame strength, and derailment stability coefficient. Methodology. The study was conducted by numerical integration and mathematical modeling of the freight car dynamic loading using the software package “Dynamics of Rail Vehicles” (“DYNRAIL”. Findings. As a result of the research for freight car dynamic coefficients determination taking into account technical conditions of the side bearers, the dependencies of the basic freight cars
9. Cooperative efforts of the materials protection control and accounting program at the electrochemical plant (Krasnoyarsk-45) in Russia-011
Energy Technology Data Exchange (ETDEWEB)
Moore, L.
1998-07-22
The USDOE Material Protection Control and Accountability Program (MPC&A) has established a Project Team with the goal of providing the Russian Electrochemical Plant (ECP) with equipment and training to enable ECP to evaluate, develop, and implement a comprehensive plan and systems for physical protection, material controls, and accountancy upgrades. The MPC&A project will provide for improvements such as risk assessments, access control upgrades, computerized MC&A, communications systems upgrades, building perimeter surveillance and intrusion detection upgrades, vault upgrades, metal and nuclear material detection upgrades, along with mass measurement and non- destructive analysis (NDA) instrumentation. This paper outlines the overall objectives of the MPC&A project at the Electrochemical Plant.
10. Accounting Information Systems in Healthcare: A Review of the Literature.
Science.gov (United States)
Hammour, Hadal; Househ, Mowafa; Razzak, Hira Abdul
2017-01-01
As information technology progresses in Saudi Arabia, the manual accounting systems have become graduallyinadequate for decision needs. Subsequently, private and public healthcare divisions in Saudi Arabia perceive Computerized accounting information system (CAIS) as a vehicle to safeguard efficient and effective flow of information during the analysis, processes, and recording of financial data. Efficient and effective flow of information improvesthe decision making of staff, thereby improving the capability of health care sectors to reduce cost of the medical services.In this paper, we define computerized accounting systems from the point of view of health informatics. Also, the challenges and benefits of supporting CAIS applications in hospitals of Saudi Arabia. With these elements, we conclude that CAIS in Saudi Arabia can serve as a valuable tool for evaluating and controlling the cost of medical services in healthcare sectors. Supplementary education on the significance of having systems of computerized accounting within hospitals for nurses, doctors, and accountants with other health care staff is warranted in future.
11. Near periodicity in dynamical systems
Institute of Scientific and Technical Information of China (English)
陈文成
1995-01-01
The notion of near periodicity is shown to be equivalent to that of weak near periodicity in dynamical systems. A sufficient condition for the positive near periodicity of a point in dynamical systems is given. The structure of nearly periodic dynamical systems is discussed, and a condition is proved to be necessary and sufficient for a dynamical system on a local compact space to be positively nearly periodic.
12. Toward self-constructing materials: a systems chemistry approach.
Science.gov (United States)
Giuseppone, Nicolas
2012-12-18
To design the next generation of so-called "smart" materials, researchers will need to develop chemical systems that respond, adapt, and multitask. Because many of these features occur in living systems, we expect that such advanced artificial systems will be inspired by nature. In particular, these new materials should ultimately combine three key properties of life: metabolism, mutation, and self-replication. In this Account, we discuss our endeavors toward the design of such advanced functional materials. First, we focus on dynamic molecular libraries. These molecular and supramolecular chemical systems are based on mixtures of reversibly interacting molecules that are coupled within networks of thermodynamic equilibria. We will explain how the superimposition of combinatorial networks at different length scales of structural organization can provide valuable hierarchical dynamics for producing complex functional systems. In particular, our experimental results highlight why these libraries are of interest for the design of responsive materials and how their functional properties can be modulated by various chemical and physical stimuli. Then, we introduce examples in which these dynamic combinatorial systems can be coupled to kinetic feedback loops to produce self-replicating pathways that amplify a selected component from the equilibrated libraries. Finally, we discuss the discovery of highly functional self-replicating supramolecular assemblies that can transfer an electric signal in space and time. We show how these wires can be directly incorporated within an electronic nanocircuit by self-organization and functional feedback loops. Because the network topologies act as complex algorithms to process information, we present these systems in this order to provide context for their potential for extending the current generation of responsive materials. We propose a general description for a potential autonomous (self-constructing) material. Such a system
13. Substitution dynamical systems spectral analysis
CERN Document Server
Queffélec, Martine
2010-01-01
This volume mainly deals with the dynamics of finitely valued sequences, and more specifically, of sequences generated by substitutions and automata. Those sequences demonstrate fairly simple combinatorical and arithmetical properties and naturally appear in various domains. As the title suggests, the aim of the initial version of this book was the spectral study of the associated dynamical systems: the first chapters consisted in a detailed introduction to the mathematical notions involved, and the description of the spectral invariants followed in the closing chapters. This approach, combined with new material added to the new edition, results in a nearly self-contained book on the subject. New tools - which have also proven helpful in other contexts - had to be developed for this study. Moreover, its findings can be concretely applied, the method providing an algorithm to exhibit the spectral measures and the spectral multiplicity, as is demonstrated in several examples. Beyond this advanced analysis, many...
14. Transformation of Inventory Accounting in Terms of Harmonization of Public Sector Accounting Systems with International Standards
OpenAIRE
Vasyl Pihosh
2014-01-01
The article investigates accounting procedures for inventory in public sector institutions. The analysis of the most important aspects of accounting for inventories is being held, which are reflected in Instructions for inventory accounting No. 125, Regulation on inventory accounting in budgetary institutions, National regulation (standard) of accounting in the public sector 123 'Inventory', International standard of accounting in the public sector 12 'Inventory', particularly, the recognitio...
15. Material accountancy measurement techniques in dry-powdered processing of nuclear spent fuels.
Energy Technology Data Exchange (ETDEWEB)
Wolf, S. F.
1999-03-24
The paper addresses the development of inductively coupled plasma-mass spectrometry (ICPMS), thermal ionization-mass spectrometry (TIMS), alpha-spectrometry, and gamma spectrometry techniques for in-line analysis of highly irradiated (18 to 64 GWD/T) PWR spent fuels in a dry-powdered processing cycle. The dry-powdered technique for direct elemental and isotopic accountancy assay measurements was implemented without the need for separation of the plutonium, uranium and fission product elements in the bulk powdered process. The analyses allow the determination of fuel burn-up based on the isotopic composition of neodymium and/or cesium. An objective of the program is to develop the ICPMS method for direct fissile nuclear materials accountancy in the dry-powdered processing of spent fuel. The ICPMS measurement system may be applied to the KAERI DUPIC (direct use of spent PWR fuel in CANDU reactors) experiment, and in a near-real-time mode for international safeguards verification and non-proliferation policy concerns.
16. System dynamics in hydropower plants
Energy Technology Data Exchange (ETDEWEB)
Stuksrud, Dag Birger
1998-12-31
The main purpose of this thesis on system dynamics in hydropower plants was to establish new models of a hydropower system where the turbine/conduits and the electricity supply and generation are connected together as one unit such that possible interactions between the two power regimes can be studied. In order to describe the system dynamics as well as possible, a previously developed analytic model of high-head Francis turbines is improved. The model includes the acceleration resistance in the turbine runner and the draft tube. Expressions for the loss coefficients in the model are derived in order to obtain a purely analytic model. The necessity of taking the hydraulic inertia into account is shown by means of simulations. Unstable behaviour and a higher transient turbine speed than expected may occur for turbines with steep characteristics or large draft tubes. The turbine model was verified previously with respect to a high-head Francis turbine; the thesis performs an experimental verification on a low-head Francis turbine and compares the measurements with simulations from the improved turbine model. It is found that the dynamic turbine model is, after adjustment, capable of describing low-head machines as well with satisfying results. The thesis applies a method called the Limited zero-pole method to obtain new rational approximations of the elastic behaviour in the conduits with frictional damping included. These approximations are used to provide an accurate state space formulation of a hydropower plant. Simulations performed with the new computer programs show that hydraulic transients such as water-hammer and mass oscillations are reflected in the electric grid. Unstable governing performance in the electric and hydraulic parts also interact. This emphasizes the need for analysing the whole power system as a unit. 63 refs., 149 figs., 4 tabs.
17. Power system dynamics stability and control
CERN Document Server
2008-01-01
Modern power systems tend to be very Complex not only due to increasing Demand for quality power, but also on Account of extensive interconnections and increasing dependence on control for optimum utilization for existing resources. A good Knowledge of system dynamics and control is Essential for secure operation of the system. This book is intended to serve the needs of the Student and practicing engineers. A Large number of illustrative examples are included to provide an insight into the application of the theory.
18. Phase change energy storage for solar dynamic power systems
Science.gov (United States)
Chiaramonte, F. P.; Taylor, J. D.
1992-01-01
This paper presents the results of a transient computer simulation that was developed to study phase change energy storage techniques for Space Station Freedom (SSF) solar dynamic (SD) power systems. Such SD systems may be used in future growth SSF configurations. Two solar dynamic options are considered in this paper: Brayton and Rankine. Model elements consist of a single node receiver and concentrator, and takes into account overall heat engine efficiency and power distribution characteristics. The simulation not only computes the energy stored in the receiver phase change material (PCM), but also the amount of the PCM required for various combinations of load demands and power system mission constraints. For a solar dynamic power system in low earth orbit, the amount of stored PCM energy is calculated by balancing the solar energy input and the energy consumed by the loads corrected by an overall system efficiency. The model assumes an average 75 kW SD power system load profile which is connected to user loads via dedicated power distribution channels. The model then calculates the stored energy in the receiver and subsequently estimates the quantity of PCM necessary to meet peaking and contingency requirements. The model can also be used to conduct trade studies on the performance of SD power systems using different storage materials.
19. Implementation status of accrual accounting system in health sector.
Science.gov (United States)
2014-07-29
Management of financial resources in health systems is one of the major issues of concern for policy makers globally. As a sub-set of financial management, accounting system is of paramount importance. In this paper, which presents part of the results of a wider research project on transition process from a cash accounting system to an accrual accounting system, we look at the impact of components of change on implementation of the new system. Implementing changes is fraught with many obstacles and surveying these challenges will help policy makers to better overcome them. The study applied a quantitative manner in 2012 at Kerman University of Medical Science in Iran. For the evaluation, a teacher made valid questionnaire with Likert scale was used (Cranach's alpha of 0.89) which included 7 change components in accounting system. The study population was 32 subordinate units of Kerman University of Medical Sciences and for data analysis, descriptive and inferential statistics and correlation coefficient in SPSS version 19 were used. Level of effect of all components on the implementation was average downward (5.06±1.86), except for the component "management & leadership (3.46±2.25)" (undesirable from external evaluators' viewpoint) and "technology (6.61±1.92) and work processes (6.35±2.19)" (middle to high from internal evaluators' viewpoint). Results showed that the establishment of accrual accounting system faces infrastructural challenges, especially the components of leadership and management and followers. As such, developing effective measures to overcome implementation obstacles should target these components.
20. Material control and accountability aspects of safeguards for the USA /sup 233/U/TH fuel recycle plant
Energy Technology Data Exchange (ETDEWEB)
Carpenter, Jr., J. A.; McNeany, S. R.; Angelini, P.; Holder, N. D.; Abraham, L.
1979-01-01
Two fuel cycles are considered. The highly enriched uranium (HEU) cycle uses uranium enriched 93% in /sup 235/U as the initial fuel. The medium enriched uranium (MEU) cycle uses uranium with a /sup 235/U enrichment less than 20% as its initial fuel. In both, /sup 233/U is bred from thorium. The HEU /sup 235/U and the /sup 233/U of both cycles are recycled. The MEU /sup 235/U is retired to waste after one reactor cycle. Typical heavy metal contents of spent fuel elements from both cycles are presented. The main functional areas of the recycle plant are Shipping, Receiving, and Storage; Reprocessing; Refabrication; and Waste Treatment. A real-time materials accountability system will manage the data provided by measurements from all four areas. Simulations of material flow used in the HTGR development program are forerunners of such a system. The material control and accountability aspects of Reprocessing and Refabrication only are discussed. The proposed accountability areas are identified and the measurement techniques appropriate to various streams crossing the boundaries of the areas are identified. Special emphasis is placed on novel nondestructive methods developed for assaying solid materials containing /sup 233/U-Th. The material form, total uranium and plutonium, and activity of selected reprocessing streams are listed. The isotopics and activity of the uranium input into Refabrication are also presented.
1. Cosmological dynamical systems
CERN Document Server
Leon, Genly
2014-01-01
In this book are studied, from the perspective of the dynamical systems, several Universe models. In chapter 1 we give a bird's eye view on cosmology and cosmological problems. Chapter 2 is devoted to a brief review on some results and useful tools from the qualitative theory of dynamical systems. They provide the theoretical basis for the qualitative study of concrete cosmological models. Chapters 1 and 2 are a review of well-known results. Chapters 3, 4, 5 and 6 are devoted to our main results. In these chapters are extended and settled in a substantially different, more strict mathematical language, several results obtained by one of us in arXiv:0812.1013 [gr-qc]; arXiv:1009.0689 [gr-qc]; arXiv:0904.1577[gr-qc]; and arXiv:0909.3571 [hep-th]. In chapter 6, we provide a different approach to the subject discussed in astro-ph/0503478. Additionally, we perform a Poincar\\'e compactification process allowing to construct a global phase space containing all the cosmological information in both finite and infinite...
2. Accounting for intra-molecular vibrational modes in open quantum system description of molecular systems.
Science.gov (United States)
Roden, Jan; Strunz, Walter T; Whaley, K Birgitta; Eisfeld, Alexander
2012-11-28
Electronic-vibrational dynamics in molecular systems that interact with an environment involve a large number of degrees of freedom and are therefore often described by means of open quantum system approaches. A popular approach is to include only the electronic degrees of freedom into the system part and to couple these to a non-Markovian bath of harmonic vibrational modes that is characterized by a spectral density. Since this bath represents both intra-molecular and external vibrations, it is important to understand how to construct a spectral density that accounts for intra-molecular vibrational modes that couple further to other modes. Here, we address this problem by explicitly incorporating an intra-molecular vibrational mode together with the electronic degrees of freedom into the system part and using the Fano theory for a resonance coupled to a continuum to derive an "effective" bath spectral density, which describes the contribution of intra-molecular modes. We compare this effective model for the intra-molecular mode with the method of pseudomodes, a widely used approach in simulation of non-Markovian dynamics. We clarify the difference between these two approaches and demonstrate that the respective resulting dynamics and optical spectra can be very different.
3. The use of management accounting systems in functionally differentiated organizations
NARCIS (Netherlands)
Bouwens, J.F.M.G.
1998-01-01
Management Accounting Systems (MAS) facilitate decision making and control in organizations. This study investigates both theoretically and empirically how MAS help managers to make their decisions. This issue is specifically addressed in a context where production and sales managers face high
4. ACCOUNTING SYSTEM OF THE MARKET OF UNIT INVESTMENT FUNDS
Directory of Open Access Journals (Sweden)
Olga A. Zhdanova
2013-01-01
Full Text Available Functions and interrelations of depositary, specialized depositary and registrar operating in the market of unit investment funds are presented and studied in the article. The conclusion is drawn on possibility of introduction of concept of accounting system in the market of unit investment funds.
5. The use of management accounting systems in functionally differentiated organizations
NARCIS (Netherlands)
Bouwens, J.F.M.G.
1998-01-01
Management Accounting Systems (MAS) facilitate decision making and control in organizations. This study investigates both theoretically and empirically how MAS help managers to make their decisions. This issue is specifically addressed in a context where production and sales managers face high level
6. Scoping Future Policy Dynamics in Raw Materials Through Scenarios Testing
Science.gov (United States)
Correia, Vitor; Keane, Christopher; Sturm, Flavius; Schimpf, Sven; Bodo, Balazs
2017-04-01
The International Raw Materials Observatory (INTRAW) project is working towards a sustainable future for the European Union in access to raw materials, from an availability, economical, and environmental framework. One of the major exercises for the INTRAW project is the evaluation of potential future scenarios for 2050 to frame economic, research, and environmental policy towards a sustainable raw materials supply. The INTRAW consortium developed three possible future scenarios that encompass defined regimes of political, economic, and technological norms. The first scenario, "Unlimited Trade," reflects a world in which free trade continues to dominate the global political and economic environment, with expectations of a growing demand for raw materials from widely distributed global growth. The "National Walls" scenario reflects a world where nationalism and economic protectionism begins to dominate, leading to stagnating economic growth and uneven dynamics in raw materials supply and demand. The final scenario, "Sustainability Alliance," examines the dynamics of a global political and economic climate that is focused on environmental and economic sustainability, leading towards increasingly towards a circular raw materials economy. These scenarios were reviewed, tested, and provided simulations of impacts with members of the Consortium and a panel of global experts on international raw materials issues which led to expected end conditions for 2050. Given the current uncertainty in global politics, these scenarios are informative to identifying likely opportunities and crises. The details of these simulations and expected responses to the research demand, technology investments, and economic components of raw materials system will be discussed.
7. A Future Vision of Nuclear Material Information Systems
Energy Technology Data Exchange (ETDEWEB)
Wimple, C.; Suski, N.; Kreek, S.; Buckley, W.; Romine, B.
1999-09-17
Modern nuclear materials accounting and safeguards measurement systems are becoming increasingly advanced as they embrace emerging technologies. However, many facilities still rely on human intervention to update materials accounting records. The demand for nuclear materials safeguards information continues to increase while general industry and government down-sizing has resulted in less availability of qualified staff. Future safeguards requirements will necessitate access to information through unattended and/or remote monitoring systems requiring minimal human intervention. Under the auspices of the Department of Energy (DOE), LLNL is providing assistance in the development of standards for minimum raw data file contents, methodology for comparing shipper-receiver values and generation of total propagated measurement uncertainties, as well as the implementation of modern information technology to improve reliability of and accessibility to nuclear materials information. An integrated safeguards and accounting system is described, along with data and methodology standards that ultimately speed access to this information. This system will semi-automate activities such as material balancing, reconciliation of shipper/receiver differences, and report generation. In addition, this system will implement emerging standards that utilize secure direct electronic linkages throughout several phases of safeguards accounting and reporting activities. These linkages will demonstrate integration of equipment in the facility that measures material quantities, a site-level computerized Materials Control and Accounting (MC&A) inventory system, and a country-level state system of accounting and control.
8. SCATS: SRB Cost Accounting and Tracking System handbook
Science.gov (United States)
Zorv, R. B.; Stewart, R. D.; Coley, G.; Higginbotham, M.
1978-01-01
The Solid Rocket Booster Cost Accounting and Tracking System (SCATS) which is an automatic data processing system designed to keep a running account of the number, description, and estimated cost of Level 2, 3, and 4 changes is described. Although designed specifically for the Space Shuttle Solid Rocket Booster Program, the ADP system can be used for any other program that has a similar structure for recording, reporting, and summing numbers and costs of changes. The program stores the alpha-numeric designators for changes, government estimated costs, proposed costs, and negotiated value in a MIRADS (Marshall Information Retrieval and Display System) format which permits rapid access, manipulation, and reporting of current change status. Output reports listing all changes, totals of each level, and totals of all levels, can be derived for any calendar interval period.
9. Computer program for the automated attendance accounting system
Science.gov (United States)
Poulson, P.; Rasmusson, C.
1971-01-01
The automated attendance accounting system (AAAS) was developed under the auspices of the Space Technology Applications Program. The task is basically the adaptation of a small digital computer, coupled with specially developed pushbutton terminals located in school classrooms and offices for the purpose of taking daily attendance, maintaining complete attendance records, and producing partial and summary reports. Especially developed for high schools, the system is intended to relieve both teachers and office personnel from the time-consuming and dreary task of recording and analyzing the myriad classroom attendance data collected throughout the semester. In addition, since many school district budgets are related to student attendance, the increase in accounting accuracy is expected to augment district income. A major component of this system is the real-time AAAS software system, which is described.
10. Integrated System of Economy-Environment Accounting of China (CSEEA) - System Design and Trial Estimation (1992)
Institute of Scientific and Technical Information of China (English)
LEI Ming
2001-01-01
On the basis of the general framework of United Nations' "indirect/satellite" accounting system--Integrated System of Environment & Economy Accounting SEEA (1992) and 93' SNA, this paper tries to construct one simple, effective and practical CSEEA, and thereby trial estimates the 1992 Chinese environmental adjusted GDP (Green GDP), under Chinese National Accounting System's reform practice.
11. A dynamic water accounting framework based on marginal resource opportunity cost
Directory of Open Access Journals (Sweden)
A. Tilmant
2014-10-01
Full Text Available Many river basins throughout the world are increasingly under pressure as water demands keep rising due to population growth, industrialization, urbanization and rising living standards. In the past, the typical answer to meet those demands focused on the supply-side and involved the construction of hydraulic infrastructures to capture more water from surface water bodies and from aquifers. As river basins were being more and more developed, downstream water users and ecosystems have become increasingly dependent on the management actions taken by upstream users. The increased interconnectedness between water users, aquatic ecosystems and the built environment is further compounded by climate change and its impact on the water cycle. Those pressures mean that it has become increasingly important to measure and account for changes in water fluxes and their corresponding economic value as they progress throughout the river system. Such basin water accounting should provide policy makers with important information regarding the relative contribution of each water user, infrastructure and management decision to the overall economic value of the river basin. This paper presents a dynamic water accounting approach whereby the entire river basin is considered as a value chain with multiple services including production and storage. Water users and reservoirs operators are considered as economic agents who can exchange water with their hydraulic neighbours at a price corresponding to the marginal value of water. Effective water accounting is made possible by keeping track of all water fluxes and their corresponding hypothetical transactions using the results of a hydro-economic model. The proposed approach is illustrated with the Eastern Nile River basin in Africa.
12. A dynamic water accounting framework based on marginal resource opportunity cost
Science.gov (United States)
Tilmant, A.; Marques, G.; Mohamed, Y.
2015-03-01
Many river basins throughout the world are increasingly under pressure as water demands keep rising due to population growth, industrialization, urbanization and rising living standards. In the past, the typical answer to meet those demands focused on the supply side and involved the construction of hydraulic infrastructures to capture more water from surface water bodies and from aquifers. As river basins have become more and more developed, downstream water users and ecosystems have become increasingly dependent on the management actions taken by upstream users. The increased interconnectedness between water users, aquatic ecosystems and the built environment is further compounded by climate change and its impact on the water cycle. Those pressures mean that it has become increasingly important to measure and account for changes in water fluxes and their corresponding economic value as they progress throughout the river system. Such basin water accounting should provide policy makers with important information regarding the relative contribution of each water user, infrastructure and management decision to the overall economic value of the river basin. This paper presents a dynamic water accounting approach whereby the entire river basin is considered as a value chain with multiple services including production and storage. Water users and reservoir operators are considered as economic agents who can exchange water with their hydraulic neighbors at a price corresponding to the marginal value of water. Effective water accounting is made possible by keeping track of all water fluxes and their corresponding hypothetical transactions using the results of a hydro-economic model. The proposed approach is illustrated with the Eastern Nile River basin in Africa.
13. Material information service system based on dynamic tracking mechanism%基于动态追踪机制的物资信息服务系统
Institute of Scientific and Technical Information of China (English)
陈士沣; 廖泰安
2011-01-01
对EPC网络系统的工作流程以及射频识别编码解析架构进行了细致研究,分析出物资保障对于动态有序的物流代替静态的物资储备,速度取代数量等一系列需求越来越迫切.根据这些需求,提出一个基于动态追踪机制的服务体系,使用射频识别码作为物资的唯一标识,并且采用对象名解析服务与信息发现服务相互结合的方式,不仅能维护了物资静态信息,还能追踪查询物资的动态信息,实现了物资动态信息的追踪,进一步实现了物资的全生命周期管理.%After seriously research on workflow of EPC network and the structure of radio frequency code analysis, getting the conclution that dynamic and sequential logistics instead of static inventories, efficiency instead of quantity are needed urgently. So a service infrastructure based on dynamic tracking mechanism is proposed to meet above requirements. The RFID code is used to be the only identification of material in the infrastructure. It adopt the mode of combining object naming service with discovery service, which not only maintain material static informations, but also track and search material dynamic informations. It can realize the tracking of dynamic informations and further achieve the entire life cycle management of materials.
14. Material flows accounting for Scotland shows the merits of a circular economy and the folly of territorial carbon reporting.
Science.gov (United States)
Pratt, Kimberley; Lenaghan, Michael; Mitchard, Edward T A
2016-12-01
It is essential that the human race limits the environmental damage created by our consumption. A realistic pathway to limiting consumption would be to transition to a system where materials are conserved and cycled through the economy as many times as possible and as slowly as possible, greatly reducing the greenhouse gas intensive processes of resource extraction, resource processing and waste management. Material flow analysis (MFA) is a method used to understand how materials are consumed within a nation. In this study, we attempt a MFA for Scotland which links carbon emissions to material consumption using data directly based on the mass of materials used in the Scottish economy. It is the first time such an analysis has been conducted for an economy in its entirety. This study aims to create a detailed material flow account (MFA) for Scotland, compare the environmental impacts and possible policy implications of different future material consumption scenarios and consider two materials, steel and neodymium, in detail. The model estimated that 11.4 Mg per capita of materials are consumed per year in Scotland, emitting 10.7 Mg CO2e per capita in the process, of which, 6.7 Mg CO2e per capita falls under territorial carbon accounting. Only the circular economy scenario for 2050 allowed for increases in living standards without increases in carbon emissions and material consumption. This result was mirrored in the steel and neodymium case studies-environmental impacts can be minimised by a national strategy that first reduces use, and then locally reuses materials. Material consumption accounts for a large proportion of the carbon emissions of Scotland. Strategic dematerialisation, particular of materials such as steel, could support future efforts to reduce environmental impact and meet climate change targets. However, policy makers should consider consumption carbon accounting boundaries, as well as territorial boundaries, if carbon savings are to be
15. Data Systems Dynamic Simulator
Science.gov (United States)
Rouff, Christopher; Clark, Melana; Davenport, Bill; Message, Philip
1993-01-01
The Data System Dynamic Simulator (DSDS) is a discrete event simulation tool. It was developed for NASA for the specific purpose of evaluating candidate architectures for data systems of the Space Station era. DSDS provides three methods for meeting this requirement. First, the user has access to a library of standard pre-programmed elements. These elements represent tailorable components of NASA data systems and can be connected in any logical manner. Secondly, DSDS supports the development of additional elements. This allows the more sophisticated DSDS user the option of extending the standard element set. Thirdly, DSDS supports the use of data streams simulation. Data streams is the name given to a technique that ignores packet boundaries, but is sensitive to rate changes. Because rate changes are rare compared to packet arrivals in a typical NASA data system, data stream simulations require a fraction of the CPU run time. Additionally, the data stream technique is considerably more accurate than another commonly-used optimization technique.
16. Enterprise marketing potential modeling taking into account optimizing and dynamic essence of the potential
Directory of Open Access Journals (Sweden)
2014-12-01
consequent enumeration. At the same time, the constituent part of the models system is constrained optimization block. Conclusions and directions of further researches. The suggested simulation and optimization models system of b2b-enterprise marketing potential result-based estimation has the following advantages: it corresponds optimizing essence of potential, takes into account marketing resources dynamics and allows to get estimation in the view of enterprise potential hierarchic levels. The suggested models system is the instrument for estimation and analysis of the future enterprise sales and marketing abilities, comparison of which with producing and financial abilities will allow to define narrow places in the analyzed enterprise activity and increase its general potential. The given models system is a part of mathematical providing to manage future enterprise abilities. The further investigations on research area have to be oriented to build models of the enterprise marketing potential estimation in integral system concerning enterprise integral potential estimation.
17. Design of advanced materials for linear and nonlinear dynamics
DEFF Research Database (Denmark)
Frandsen, Niels Morten Marslev
The primary catalyst of this PhD project has been an ambition to design advanced materials and structural systems including, and possibly even exploiting, nonlinear phenomena such as nonlinear modal interaction leading to energy conversion between modes. An important prerequisite for efficient...... design is accurate and somewhat simple analysis tools, as well as a fundamental understanding of the physical phenomena responsible for the relevant effects. The emphasis of this work lies primarily in the investigation of various advanced material models, developing the necessary analytical tools...... to reveal the fundamental dynamic characteristics and thus the relevant design parameters.The thesis is built around the characterization of two one-dimensional, periodic material systems. The first is a nonlinear mass-spring chain with periodically varying material properties, representing a simple...
18. Dynamic Characterization of Thin Film Magnetic Materials
Science.gov (United States)
Gu, Wei
A broadband dynamic method for characterizing thin film magnetic material is presented. The method is designed to extract the permeability and linewidth of thin magnetic films from measuring the reflection coefficient (S11) of a house-made and short-circuited strip line testing fixture with or without samples loaded. An adaptive de-embedding method is applied to remove the parasitic noise of the housing. The measurements were carried out with frequency up to 10GHz and biasing magnetic fields up to 600 Gauss. Particular measurement setup and 3-step experimental procedures are described in detail. The complex permeability of a 330nm thick continuous FeGaB, 435nm thick laminated FeGaB film and a 100nm thick NiFe film will be induced dynamically in frequency-biasing magnetic field spectra and compared with a theoretical model based on Landau-Lifshitz-Gilbert (LLG) equations and eddy current theories. The ferromagnetic resonance (FMR) phenomenon can be observed among these three magnetic materials investigated in this thesis.
19. Duality in Dynamic Fuzzy Systems
OpenAIRE
Yoshida, Yuji
1995-01-01
This paper shows the resolvent equation, the maximum principle and the co-balayage theorem for a dynamic fuzzy system. We define a dual system for the dynamic fuzzy system, and gives a duality for Snell's optimal stopping problem by the dual system.
20. Dynamics of complex quantum systems
CERN Document Server
2014-01-01
This book gathers together a range of similar problems that can be encountered in different fields of modern quantum physics and that have common features with regard to multilevel quantum systems. The main motivation was to examine from a uniform standpoint various models and approaches that have been developed in atomic, molecular, condensed matter, chemical, laser and nuclear physics in various contexts. The book should help senior-level undergraduate, graduate students and researchers putting particular problems in these fields into a broader scientific context and thereby taking advantage of well-established techniques used in adjacent fields. This second edition has been expanded to include substantial new material (e.g. new sections on Dynamic Localization and on Euclidean Random Matrices and new chapters on Entanglement, Open Quantum Systems, and Coherence Protection). It is based on the author’s lectures at the Moscow Institute of Physics and Technology, at the CNRS Aimé Cotton Laboratory, and on ...
1. 17 CFR 256.01-3 - General structure of accounting system.
Science.gov (United States)
2010-04-01
... accounting system. 256.01-3 Section 256.01-3 Commodity and Securities Exchanges SECURITIES AND EXCHANGE... accounting system. (a) The accounts provided herein are in two general categories: Balance sheet accounts and... account numbers in the Uniform System of Accounts for Public Utilities and Licensees (18 CFR Part 101)...
2. Lunar Materials Handling System Project
Data.gov (United States)
National Aeronautics and Space Administration — The Lunar Materials Handling System (LMHS) is a method for transfer of lunar soil into and out of process equipment in support of in situ resource utilization...
3. 78 FR 71532 - Amendments to Material Control and Accounting Regulations and Proposed Guidance for Fuel Cycle...
Science.gov (United States)
2013-11-29
...: I. Background On November 8, 2013 (78 FR 67225; NRC-2009-0096), the NRC published for public comment a proposed rule to amend its regulations for MC&A of SNM. Also on November 8, 2013 (78 FR 67224; NRC... Control and Accounting Regulations and Proposed Guidance for Fuel Cycle Facility Material Control...
4. 77 FR 60482 - Regulatory Guide 5.67, Material Control and Accounting for Uranium Enrichment Facilities...
Science.gov (United States)
2012-10-03
... guidance is no longer needed. RG 5.67 was published in December 1993 to provide guidance to the Paducah and Portsmouth Gaseous Diffusion Plants (GDPs) to develop their material control and accounting (MC&A) programs... guide because NUREG/CR-5734 is more comprehensive than RG 5.67 and is applicable to the Paducah GDP...
5. Structured assessment approach version 1. License submittal document content and format for material control and accounting assessment. Volume II
Energy Technology Data Exchange (ETDEWEB)
Parziale, A.A.; Sacks, I.J.
1979-10-01
A methodology, the Structured Assessment Approach, has been developed for the assessment of the effectiveness of material control and accounting (MC and A) safeguards systems at nuclear fuel cycle facilities. This methodology has been refined into a computational tool, the SAA Version 1 computational package, that was used first to analyze a hypothetical fuel cycle facility and used more recently to assess operational nuclear plants. The Version 1 analysis package is designed to analyze safeguards systems that prevent the diversion of special nuclear material (SNM) from nuclear fuel cycle facilities and to provide assurance that diversion has not occurred. This report is the second volume, the License Submittal Document Content and Format for Material Control and Accounting Assessment, of a four-volume document. It presents the content and format of the LSD necessary for Material Control and Accounting (MC and A) assessment with the SAA Version 1. The LSD is designed to provide the necessary data input to perform all four stages of analyses associated with the SAA. A full-size but Hypothetical Fuel Cycle Facility (HFCF) is used as an example to illustrate the required input data content and data format and to illustrate the procedure for generating the LSD. Generation of the LSD is the responsibility of the nuclear facility licensee applicant.
6. Development of Virtual Account System for Research Projects Based on J2EE
Institute of Scientific and Technical Information of China (English)
2006-01-01
Based on the analysis of developing target, function and constitution of research projects system for remote management, the virtual account system is established on 3 layers of B/S mode. The development process of virtual account system is realized by JSP/Servlets development language and MySQL database under windows server 2003 platform. At the same time, network security module of the system has been realized to reduce the influence caused by network security incidents. The system is capable of updating the information of vertical and horizontal projects dynamically and assigning virtual funds on WWW. Also, it realizes the query, statistical analysis function and so on.Practical results show that the system is a successful system for analyzing the various projects index of different departments.
7. PLASTICITY OF SELECTED METALLIC MATERIALS IN DYNAMIC DEFORMATION CONDITIONS
Directory of Open Access Journals (Sweden)
Jacek PAWLICKI
2014-06-01
Full Text Available Characteristics of a modernized flywheel machine has been presented in the paper. The laboratory stand enables to perform dynamic tensile tests and impact bending with a linear velocity of the enforcing element in the range of 5÷40 m/s. A new data acquisition system, based on the tensometric sensors, allows for significant qualitative improvement of registered signals. Some preliminary dynamic forming tests were performed for the selected group of metallic materials. Subsequent microstructural examinations and identification of the fracture type enabled to describe a correlation between strain rate, strain and microstructure.
8. The Lower Extremities Exoskeleton Actuator Dynamics Research Taking into Account Support Reaction
Directory of Open Access Journals (Sweden)
A. A. Vereikin
2014-01-01
Full Text Available The article shows high relevance of research, aimed at the robotic exoskeleton creation. It defines some problems related to the process of their designing; including a lack of power supply to provide enough autonomy, and difficulties of man-machine complex control. There is a review of literature on the walking robots with tree-like kinematic structure development. This work reflects the continuing investigations, currently conducted by the authors, and relies heavily on the results of previous works, devoted to this subject.The article presents the exoskeleton dynamics equation, taking into account the impact of external forces and torques, as well as external relations imposed. Using a model of lower extremities exoskeleton developed in SolidWorks software complex, baricentric parameters of the actuator links were found. The different types of movements, committed due to harmonic changes of generalized coordinates in exoskeleton degrees of mobility, equipped with electrohydraulic actuators, were analyzed. The laws of generalized coordinate changes in time, corresponding to the worst case loading, were found. All the necessary input data for the exoskeleton dynamics equation solution were determined.The numerical values of all components of the dynamics equation were obtained as result of the dynamics equation simulation. In this case, the exoskeleton actuator load capacity was assumed to be 50 kg. The article shows dependences of torque and power in the actuator degrees of mobility on the time, as well as a curve of total capacity of all drives both, ignoring and taking into consideration the support surface reactions. Obtained dependences are the initial data for the calculation of the drive system.The proposed method for determination of exoskeleton energy parameters allows developer to perform a prompt evaluation of various options for the actuator design in accordance with the selected criteria. As a main evaluation criterion, a minimum
9. Materials challenges for nuclear systems
Directory of Open Access Journals (Sweden)
Todd Allen
2010-12-01
Full Text Available The safe and economical operation of any nuclear power system relies to a great extent, on the success of the fuel and the materials of construction. During the lifetime of a nuclear power system which currently can be as long as 60 years, the materials are subject to high temperature, a corrosive environment, and damage from high-energy particles released during fission. The fuel which provides the power for the reactor has a much shorter life but is subject to the same types of harsh environments. This article reviews the environments in which fuels and materials from current and proposed nuclear systems operate and then describes how the creation of the Advanced Test Reactor National Scientific User Facility is allowing researchers from across the United States to test their ideas for improved fuels and materials.
10. Synchronization dynamics of two different dynamical systems
Energy Technology Data Exchange (ETDEWEB)
Luo, Albert C.J., E-mail: [email protected] [Department of Mechanical and Industrial Engineering, Southern Illinois University Edwardsville, Edwardsville, IL 62026-1805 (United States); Min Fuhong [Department of Mechanical and Industrial Engineering, Southern Illinois University Edwardsville, Edwardsville, IL 62026-1805 (United States)
2011-06-15
Highlights: > Synchronization dynamics of two distinct dynamical systems. > Synchronization, de-synchronization and instantaneous synchronization. > A controlled pendulum synchronizing with the Duffing oscillator. > Synchronization invariant set. > Synchronization parameter map. - Abstract: In this paper, synchronization dynamics of two different dynamical systems is investigated through the theory of discontinuous dynamical systems. The necessary and sufficient conditions for the synchronization, de-synchronization and instantaneous synchronization (penetration or grazing) are presented. Using such a synchronization theory, the synchronization of a controlled pendulum with the Duffing oscillator is systematically discussed as a sampled problem, and the corresponding analytical conditions for the synchronization are presented. The synchronization parameter study is carried out for a better understanding of synchronization characteristics of the controlled pendulum and the Duffing oscillator. Finally, the partial and full synchronizations of the controlled pendulum with periodic and chaotic motions are presented to illustrate the analytical conditions. The synchronization of the Duffing oscillator and pendulum are investigated in order to show the usefulness and efficiency of the methodology in this paper. The synchronization invariant domain is obtained. The technique presented in this paper should have a wide spectrum of applications in engineering. For example, this technique can be applied to the maneuvering target tracking, and the others.
11. Accounting information system and management’s decision making process
Directory of Open Access Journals (Sweden)
2015-07-01
Full Text Available In this paper, we address the management’s decision making process and examine the effect of accounting information system (AIS in PARS GARMA holding organization in making sound and effective decisions and inform the reader on how AIS influences on the management decisions in 6 major perspectives including quality, accuracy, economic, validity, speed and on time concepts. The major source of data to this research is primary data through the administration of questionnaires. Regression and correlation analysis was used for the data analysis. The findings show that accounting information system had a significant and positive role in PARS GARMA holding management decisions process in several perspectives but AIS had no significant impact on speed of decision making.
12. Rational Observational Systems of Educational Accountability and Reform
Directory of Open Access Journals (Sweden)
Audrey Amrein-Beardsley
2015-08-01
Full Text Available There is something incalculable about teacher expertise and whether it can be observed, detected, quantified, and as per current educational policies, used as an accountability tool to hold America's public school teachers accountable for that which they do (or do not do well. In this commentary, authors (all of whom are former public school teachers argue that rubric-based teacher observational systems, developed to assess the extent to which teachers adapt and follow sets of rubric-based rules, might actually constrain teacher expertise. Moreover, authors frame their comments using the Dreyfus Model (1980, 1986 to illustrate how observational systems and the rational conceptions on which they are based might be stifling educational progress and reform.
13. Collective dynamics of multicellular systems
R Maithreye; C Suguna; Somdatta Sinha
2011-11-01
We have studied the collective behaviour of a one-dimensional ring of cells for conditions when the individual uncoupled cells show stable, bistable and oscillatory dynamics. We show that the global dynamics of this model multicellular system depends on the system size, coupling strength and the intrinsic dynamics of the cells. The intrinsic variability in dynamics of the constituent cells are suppressed to stable dynamics, or modified to intermittency under different conditions. This simple model study reveals that cell–cell communication, system size and intrinsic cellular dynamics can lead to evolution of collective dynamics in structured multicellular biological systems that is significantly different from its constituent single-cell behaviour.
14. Performance consequences of management accounting system information usage in Jordan
Directory of Open Access Journals (Sweden)
Hamzah Al-Mawali
2013-04-01
Full Text Available The purpose of this study is to contribute to the body of knowledge in the area of management accounting systems (MAS within the context of Jordanian manufacturing companies. However, the current study empirically investigated the relationship between MAS information usage and companies' performance. Data were collected from manufacturing companies listed in Amman Stock Exchange. The results of this study provide ample confirmation on the role of the usage of MAS information in enhance the manufacturing companies performance in Jordan
15. Illicit crops: A look from the national accounts system
Directory of Open Access Journals (Sweden)
Carmen Lucía Bazzani C.
2012-07-01
Full Text Available This article presents an analysis of the evolution of illicit crops in Colombia through the National Accounts System, which provides a basis for the study of transactions and the use of the product in an economy. Through the input-output methodology it is shown that, thanks to the drug policy action developed by the national government, its importance in generation of value added has been changing and decreasing over time.
16. Dynamical Systems for Creative Technology
NARCIS (Netherlands)
van Amerongen, J.
2010-01-01
Dynamical Systems for Creative Technology gives a concise description of the physical properties of electrical, mechanical and hydraulic systems. Emphasis is placed on modelling the dynamical properties of these systems. By using a system’s approach it is shown that a limited number of mathematical
17. Chaos for Discrete Dynamical System
Directory of Open Access Journals (Sweden)
Lidong Wang
2013-01-01
Full Text Available We prove that a dynamical system is chaotic in the sense of Martelli and Wiggins, when it is a transitive distributively chaotic in a sequence. Then, we give a sufficient condition for the dynamical system to be chaotic in the strong sense of Li-Yorke. We also prove that a dynamical system is distributively chaotic in a sequence, when it is chaotic in the strong sense of Li-Yorke.
18. ACCOUNTING PRACTICES FROM FINANCIAL INSTRUMENTS DISCLOSURE PERSPECTIVE – THE CASE OF ROMANIAN BANKING SYSTEM
Directory of Open Access Journals (Sweden)
Stefanescu Cristina Alexandrina
2012-12-01
disclosure in Romanian banking system harmonized with international requirements? Was there a progress in this respect in the latest years?†The research methodology used for achieving our goal is based on both static and dynamic analysis using appropriate statistical tools – concentration indices (H or Herfindahl index for measuring the improvements in financial instruments’ disclosure practices,, thus pointing out the degree of material harmonization reached step by step as well as the overall progress. In this respect, firstly, we developed a disclosure checklist structured on three sections dealing with financial instruments’ general disclosures, derivatives and hedge accounting and risk disclosures. The results of the performed analysis reveal that accounting practices in Romanian banking sector as regards disclosures related to financial instruments experienced a continuous improvement both at individual and consolidated level, but the level of material harmonization is still relatively moderate. In case of individual financial reporting this can be explained by the recently introduced requirement of preparing financial statements in accordance with IFRS and only for informative purposes. Thus, by now we can talk about a real material harmonization just in case of consolidated financial reporting. Unlike prior research studies which were focused on similar goals - to measure accounting harmonization around the world, our paper provides a particular approach on a specific business field, the banking one that was not separately explored on this topic before. Thus, we considered for analysis its related accounting practices focusing on financial instruments disclosure, which is a particular issue, too, thus enriching the research literature on this field.
19. Landscape Construction in Dynamical Systems
Science.gov (United States)
Tang, Ying; Yuan, Ruoshi; Wang, Gaowei; Ao, Ping
The idea of landscape has been recently applied to study various of biological problems. We demonstrate that a dynamical structure built into nonlinear dynamical systems allows us to construct such a global optimization landscape, which serves as the Lyapunov function for the ordinary differential equation. We find exact constructions on the landscape for a class of dynamical systems, including a van der Pol type oscillator, competitive Lotka-Volterra systems, and a chaotic system. The landscape constructed provides a new angle for understanding and modelling biological network dynamics.
20. Canopy Dynamics in Nanoscale Ionic Materials
KAUST Repository
Jespersen, Michael L.
2010-07-27
Nanoscale ionic materials (NIMS) are organic - inorganic hybrids in which a core nanostructure is functionalized with a covalently attached corona and an ionically tethered organic canopy. NIMS are engineered to be liquids under ambient conditions in the absence of solvent and are of interest for a variety of applications. We have used nuclear magnetic resonance (NMR) relaxation and pulse-field gradient (PFG) diffusion experiments to measure the canopy dynamics of NIMS prepared from 18-nm silica cores modified by an alkylsilane monolayer possessing terminal sulfonic acid functionality, paired with an amine-terminated ethylene oxide/propylene oxide block copolymer canopy. Carbon NMR studies show that the block copolymer canopy is mobile both in the bulk and in the NIMS and that the fast (ns) dynamics are insensitive to the presence of the silica nanoparticles. Canopy diffusion in the NIMS is slowed relative to the neat canopy, but not to the degree predicted from the diffusion of hard-sphere particles. Canopy diffusion is not restricted to the surface of the nanoparticles and shows unexpected behavior upon addition of excess canopy. Taken together, these data indicate that the liquid-like behavior in NIMS is due to rapid exchange of the block copolymer canopy between the ionically modified nanoparticles. © 2010 American Chemical Society.
1. Topological dimension and dynamical systems
CERN Document Server
Coornaert, Michel
2015-01-01
Translated from the popular French edition, the goal of the book is to provide a self-contained introduction to mean topological dimension, an invariant of dynamical systems introduced in 1999 by Misha Gromov. The book examines how this invariant was successfully used by Elon Lindenstrauss and Benjamin Weiss to answer a long-standing open question about embeddings of minimal dynamical systems into shifts. A large number of revisions and additions have been made to the original text. Chapter 5 contains an entirely new section devoted to the Sorgenfrey line. Two chapters have also been added: Chapter 9 on amenable groups and Chapter 10 on mean topological dimension for continuous actions of countable amenable groups. These new chapters contain material that have never before appeared in textbook form. The chapter on amenable groups is based on Følner’s characterization of amenability and may be read independently from the rest of the book. Although the contents of this book lead directly to several active ar...
2. Topological theory of dynamical systems recent advances
CERN Document Server
Aoki, N
1994-01-01
This monograph aims to provide an advanced account of some aspects of dynamical systems in the framework of general topology, and is intended for use by interested graduate students and working mathematicians. Although some of the topics discussed are relatively new, others are not: this book is not a collection of research papers, but a textbook to present recent developments of the theory that could be the foundations for future developments. This book contains a new theory developed by the authors to deal with problems occurring in diffentiable dynamics that are within the scope of general topology. To follow it, the book provides an adequate foundation for topological theory of dynamical systems, and contains tools which are sufficiently powerful throughout the book. Graduate students (and some undergraduates) with sufficient knowledge of basic general topology, basic topological dynamics, and basic algebraic topology will find little difficulty in reading this book.
3. Material Discovery and Design with Dynamic Charge Reactive Potentials
Science.gov (United States)
Sinnott, Susan
2015-03-01
Atomic scale computational simulations of multi-phase systems is increasingly important as our ability to simulate nanometer-sized systems becomes routine. The recently developed charge optimized many body potential (COMB) potentials have significantly enhanced our ability to carry out atomic-scale simulations of heterogeneous material systems. The formalism of this potential combines variable charge electrostatic interactions with a classical analytical bond-order potential. It therefore has the capacity to adaptively model metallic, covalent, ionic, and van der Waals bonding within the same simulation cell and dynamically determine the charges on individual atoms according to the local environment. The utility of the COMB potentials is illustrated for materials design and discovery by exploring the structure, stability, mechanical properties, and thermal properties of intermetallic systems and oxide-metal interfaces. They are also used to address key questions associated with corrosion, thin film growth, and heterogeneous catalysis.
4. THE IMPACT OF ENTERPRISE RESOURCE PLANNING SYSTEMS ON MANAGEMENT ACCOUNTING
Directory of Open Access Journals (Sweden)
Andreea Gabriela PONORÎCĂ
2014-05-01
Full Text Available The added value on the ongoing improvement process of forecasts for financial and non-financial information systems is the main object of this study during nowadays context. Our results reveal the findings of an empirical research on the communication with various software vendors, such as SAP or Oracle, confirming the hypothesis that enterprise resource planning systems are not so well connected with the field of financial reporting analysis, but strongly linked with the management accounting field. Our study is and will be further opened for future research, passing over the limits of resource planning.
5. Mechatronic systems and materials III
CERN Document Server
Gosiewski, Zdzislaw
2009-01-01
This very interesting volume is divided into 24 sections; each of which covers, in detail, one aspect of the subject-matter: I. Industrial robots; II. Microrobotics; III. Mobile robots; IV. Teleoperation, telerobotics, teleoperated semi-autonomous systems; V. Sensors and actuators in mechatronics; VI. Control of mechatronic systems; VII. Analysis of vibration and deformation; VIII. Optimization, optimal design; IX. Integrated diagnostics; X. Failure analysis; XI. Tribology in mechatronic systems; XII. Analysis of signals; XIII. Measurement techniques; XIV. Multifunctional and smart materials;
6. Dynamical systems examples of complex behaviour
CERN Document Server
Jost, Jürgen
2005-01-01
Our aim is to introduce, explain, and discuss the fundamental problems, ideas, concepts, results, and methods of the theory of dynamical systems and to show how they can be used in speci?c examples. We do not intend to give a comprehensive overview of the present state of research in the theory of dynamical systems, nor a detailed historical account of its development. We try to explain the important results, often neglecting technical re?nements 1 and, usually, we do not provide proofs. One of the basic questions in studying dynamical systems, i.e. systems that evolve in time, is the construction of invariants that allow us to classify qualitative types of dynamical evolution, to distinguish between qualitatively di?erent dynamics, and to studytransitions between di?erent types. Itis also important to ?nd out when a certain dynamic behavior is stable under small perturbations, as well as to understand the various scenarios of instability. Finally, an essential aspect of a dynamic evolution is the transformat...
7. INFORMATION IN THE SYSTEM OF MANAGEMENT ACCOUNTING AND ITS USERS
Directory of Open Access Journals (Sweden)
Aneliya Galinova
2016-06-01
Full Text Available In an market economy, where each entity has autonomy in developing their production programs, production plans and social development to identify strategies pricing policy has significantly increased the responsibility of the management of taken by them management decisions. In order to develop effective and operative decisions managers need reliable information for both the production and the financial position of the company. As is known, traditional accounting, which covers much of the existing information systems do not provide managers at all levels of operational information, and this is achieved through management accounting. Namely the creation of nontraditional systems for forming information about production costs and the financial results, the use of new methods to management, the increased value of the information obtained for decision making appears at present one of the most actual problems of accounting, control and analysis of economic activity. In this article we aim to define the concept of management information, to systematize the information needs of different users and qualitative characteristics that should have useful information.
8. Role of E-Payment System in Promoting Accountability in Government Ministries as Perceived by Accounting Education Graduates and Accountants in Ministry of Finance of Ebonyi State
Science.gov (United States)
Azih, Nonye; Nwagwu, Lazarus
2015-01-01
This paper identified the role of electronic payment system in promoting accountability in government ministries as well as the challenges facing the implementation of e-payment in government ministries in Ebonyi State. The study was guided by two research questions and two hypotheses. The population of the study comprised of 112 accountants as…
9. INTEGRATION LEVEL OF FINANCIAL AND MANAGEMENT ACCOUNTING SYSTEMS WITH THE ACCOUNTING CONVERGENCE PROCESS AND THE EFFECTIVENESS OF CONTROLLERSHIP
Directory of Open Access Journals (Sweden)
Andréia Carpes Dani
2014-09-01
Full Text Available This study aims to verify the integration level between the financial and management accounting systems as a result of the convergence process with the international accounting standards and of the effectiveness of controllership in Brazilian companies. A descriptive research was undertaken, based on the application of the questionnaire by Angelkort and Weißenberger (2011 to the 500 Best and Biggest of Revista Exame, issue 2011, using a sample of 32 companies that answered the research. The correlations between the integration level of the financial and management accounting systems and the variables “consistency of financial language”, “quality of services provided” and “degree of influence in decision making”, during the convergence period with the international accounting standards, were positive and moderate. It was also observed that the period before the accounting convergence (2004 till 2007 showed a better integration level of the financial and management accounting systems than the accounting convergence period (2008 till 2011. In conclusion, the accounting convergence process increased the integration level of the financial and management accounting systems in the investigated companies, as well as the effectiveness of controllership, particularly in the consistency of the financial language, in the quality of the services provided and in the influence of the controllers’ services on these companies’ decisions.
10. Dynamics of Drying in Phenolically Tanned Materials
Institute of Scientific and Technical Information of China (English)
Julian F. V. Vincent
2004-01-01
The cuticle of a maggot goes through a mechanical transition when it dries, increasing in stiffness by about an order of magnitude (e. g. from 0.5 GPa to 5 GPa) as the water content drops from about 1 g/g (weight of water per unit dry weight) to 0.4 g/g. Thus stiffness represents the loss of freezable water and is more or less diagnostic of a material stabilized by hydrogen bonds. Further loss in water results in a smaller increase in stiffness. In natural systems the water content is controlled by the addition of phenolic residues, resulting in tanning or sclerotisation, which drives the matrix components towards co-operative interaction and makes the material permanently waterproof.
11. INVESTIGATION OF FORWARD TRANSACTIONS IN TERMS OF UNIFORM ACCOUNTING SYSTEM AND ACCOUNTING STANDARTS
Directory of Open Access Journals (Sweden)
Mehmet KAYGUSUZOĞLU
2010-06-01
Full Text Available Accurate financial reporting in enterprises is very important particularly for business management as well as for everyone. Revenues from operating activities and incurred expenses as a true and fair measurement, recording and reporting pose to be crucial in this respect. Term used in sales transactions from the forward transactions consists of a portion of interest. In this study, interest arising from forward transactions in accordance with accounting standards will be analyzed in what has been discussed. First of all, interest arising from forward transactions is explained with regard to current accounting practices (THP and tax regulation, and then the adjustments, which might be implemented within the scope of Turkish Accounting Standards, is investigated. Decomposition of interest that have great impact on the outcome of the operations of enterprises and accounting records are explained by the help of examplary cases. To the extent of compliance standards the necessity of adding some new accounts to THP are emphasized.
12. Quasimolecular Dynamic Simulation for Bending Fracture of Laminar Composite Materials
Institute of Scientific and Technical Information of China (English)
2001-01-01
Recently, quasimolecular dynamics has been successfully used to simulate the deformation characteristics of actual size solid materials. In quasimolecular dynamics, which is an attempt to bridge the gap between atomistic and continuum simulations, molecules are aggregated into large units, called quasimolecules, to evaluate large scale material behavior. In this paper, a 2-dimensional numerical simulation using quasimolecular dynamics was performed to investigate laminar composite material fractures and crack propagation behavior in the uniform bending of laminar composite materials. It was verified that under bending deformation laminar composite materials deform quite differently from homogeneous materials
13. Structural dynamics in rotating systems
Science.gov (United States)
Kiraly, Louis J.
1993-01-01
Major issues and recent advances in the structural dynamics of rotating systems are summarized. The objectives and benefits of such systems are briefly discussed. Directions for future research are suggested.
14. Chaotic Dynamics in Hybrid Systems
NARCIS (Netherlands)
P.J. Collins (Pieter)
2008-01-01
htmlabstractIn this paper we give an overview of some aspects of chaotic dynamics in hybrid systems, which comprise different types of behaviour. Hybrid systems may exhibit discontinuous dependence on initial conditions leading to new dynamical phenomena. We indicate how methods from topological
15. Chaotic dynamics in hybrid systems
NARCIS (Netherlands)
P.J. Collins (Pieter)
2008-01-01
htmlabstractIn this paper we give an overview of some aspects of chaotic dynamics in hybrid systems, which comprise different types of behaviour. Hybrid systems may exhibit discontinuous dependence on initial conditions leading to new dynamical phenomena. We indicate how methods from topological
16. A new hyperchaotic dynamical system
Institute of Scientific and Technical Information of China (English)
Liu Chong-Xin
2007-01-01
In this paper a new hyperchaotic system is reported. Some basic dynamical properties, such as continuous specare studied. Dynamical behaviours of the new hyperchaotic system are proved by not only numerical simulation and brief theoretical analysis but also an electronic circuit experiment.
17. Depository Accounting of Securities in the Ukrainian Stock Market Regulation System
Directory of Open Access Journals (Sweden)
Veriha Hanna V.
2016-02-01
Full Text Available The aim of the article is to study the procedures, technologies, prudential regulation of depository accounting of securities in the system of the Ukrainian stock market infrastructure and identify directions of its improvement. The article analyzes the dynamics of the number of licenses issued by types of professional activity in the stock market. The necessity for further improvement of mechanisms of the updated system of depository accounting of securities in Ukraine has been proved. There have been developed the following recommendations: to improve the unified rules of accounting and regulation support of the system of risk management of depository activity; develop tools for prudential regulation of depository activity and strengthen the control over fulfillment of prudential standards by the Central Depository and depository institutions; create the necessary conditions for the practical implementation of legal norms concerning establishment of clearing institutions and increase in the level of competition between depositaries; expand the correspondent relations of the Central Depository in relation to the establishment of international depositary relations for the liberalization of the international movement of securities; use segregated accounts providing the possibility of storage of client funds separately from the funds of the transfer bank to protect the capital of the issuer and investor from risks of any force majeure situations; mediate the movement of funds at implementing dividend payments through participants of the accounting system: issuer-the Central Depository-depository institution-depositor.
18. Dynamic material strength measurement utilizing magnetically applied pressure-shear
Directory of Open Access Journals (Sweden)
Alexander C.S.
2012-08-01
Full Text Available Magnetically applied pressure-shear (MAPS is a recently developed technique used to measure dynamic material strength developed at Sandia National Laboratories utilizing magneto-hydrodynamic (MHD drive pulsed power systems. MHD drive platforms generate high pressures by passing a large current through a pair of parallel plate conductors which, in essence, form a single turn magnet coil. Lorentz forces resulting from the interaction of the self-generated magnetic field and the drive current repel the plates and result in a high pressure ramp wave propagating in the conductors. This is the principle by which the Sandia Z Machine operates for dynamic material testing. MAPS relies on the addition of a second, external magnetic field applied orthogonally to both the drive current and the self-generated magnetic field. The interaction of the drive current and this external field results in a shear wave being induced directly in the conductors. Thus both longitudinal and shear stresses are generated. These stresses are coupled to a sample material of interest where shear strength is probed by determining the maximum transmissible shear stress in the state defined by the longitudinal compression. Both longitudinal and transverse velocities are measured via a specialized velocity interferometer system for any reflector (VISAR. Pressure and shear strength of the sample are calculated directly from the VISAR data. Results of tests on several materials at modest pressures (∼10GPa will be presented and discussed.
19. Recurrence for random dynamical systems
CERN Document Server
Marie, Philippe
2009-01-01
This paper is a first step in the study of the recurrence behavior in random dynamical systems and randomly perturbed dynamical systems. In particular we define a concept of quenched and annealed return times for systems generated by the composition of random maps. We moreover prove that for super-polynomially mixing systems, the random recurrence rate is equal to the local dimension of the stationary measure.
20. ROLLING MILL SYSTEM DYNAMIC DESIGN
Institute of Scientific and Technical Information of China (English)
2001-01-01
It is studied how the aluminum foil chatter mark is produced and controlledThe stableness of hydraulic AGC system,fluid vibration of capsule system,and electromechanical coupling of AC/AC VVVF system and dec oupling are also studiedIt is shown that rolling mill design should go to syst em dynamic design from traditional designThe framed drawing of system dynamic design program is presented
1. George Kuzmycz Training Center : 5 years of American-Ukrainian efforts in the field of material control and accounting
Energy Technology Data Exchange (ETDEWEB)
Gavrilyuk, V. I. (Viktor I.); Gavrylyuk, A. V. (Anna V.); Kirischuk, V. I. (Vladimir I.); Romanova, O. P. (Olena P.); Robinson, P. (Phil); Dickerson, S. (Sarah); Kuzminski, J. (Jozef); Sheppard, G. A. (Gregory A.)
2004-01-01
The George Kuzmycz Training Center for Physical Protection, Control and Accounting of Nuclear Material (GKTC) was established in October 1998 at the Kiev Institute for Nuclear Research. During the past six years, about 700 professionals from all Ukrainian nuclear installations, executive and regulatory bodies were trained at the GKTC. Future Material Control and Accounting (MC&A) training courses are going to be held even more frequently because Ukraine has already signed the Additional Model Protocol and its ratification by Ukrainian Parliament is expected to happen very soon. Additionally, a number of new training courses will be developed. US DOE trough Argonne National Laboratory has made significant efforts to transfer Automated Inventory/Material Accounting System (AIMAS) software to Ukraine. As a result, AIMAS software can be used as a basic code for the development of the Computerized MC&A System for all Ukrainian nuclear facilities despite their differences. In 2003, a new laboratory for Nondestructive Assay (NDA) was established with assistance from the U.S. Department of Energy. As a result, GKTC training capabilities will increase substantially. Furthermore, in order to increase the efficiency of NDA laboratory, it is planned to use the NDA equipment for a program of interdiction of illicit traffic of nuclear materials in Ukraine. American-Ukrainian MC&A efforts for the last 6 years, the problems encountered and the solutions to these problems, as well as comments, suggestions and recommendations for future activity at GKTC to promote and improve the nuclear material management culture in Ukraine are discussed in detail.
2. Improved accounting of emissions from utility energy storage system operation.
Science.gov (United States)
Denholm, Paul; Holloway, Tracey
2005-12-01
Several proposed utility-scale energy storage systems in the U.S. will use the spare output capacity of existing electric power systems to create the equivalent of new load-following plants that can rapidly respond to fluctuations in electricity demand and increase the flexibility of baseload generators. New energy storage systems using additional generation from existing plants can directly compete with new traditional sources of load-following and peaking electricity, yet this application of energy storage is not required to meet many of the Clean Air Act standards required of new electricity generators (e.g., coal- or gas-fired power plants). This study evaluates the total emissions that will likely result from the operation of a new energy storage facility when coupled with an average existing U.S. coal-fired power plant and estimates that the emission rates of SO2 and NOx will be considerably higher than the rate of a new plant meeting Clean Air Act standards, even accounting for the efficiency benefits of energy storage. This study suggests that improved emissions "accounting" might be necessary to provide accurate environmental comparisons between energy storage and more traditional sources of electricity generation.
3. Structural materials challenges for advanced reactor systems
Science.gov (United States)
Yvon, P.; Carré, F.
2009-03-01
Key technologies for advanced nuclear systems encompass high temperature structural materials, fast neutron resistant core materials, and specific reactor and power conversion technologies (intermediate heat exchanger, turbo-machinery, high temperature electrolytic or thermo-chemical water splitting processes, etc.). The main requirements for the materials to be used in these reactor systems are dimensional stability under irradiation, whether under stress (irradiation creep or relaxation) or without stress (swelling, growth), an acceptable evolution under ageing of the mechanical properties (tensile strength, ductility, creep resistance, fracture toughness, resilience) and a good behavior in corrosive environments (reactor coolant or process fluid). Other criteria for the materials are their cost to fabricate and to assemble, and their composition could be optimized in order for instance to present low-activation (or rapid desactivation) features which facilitate maintenance and disposal. These requirements have to be met under normal operating conditions, as well as in incidental and accidental conditions. These challenging requirements imply that in most cases, the use of conventional nuclear materials is excluded, even after optimization and a new range of materials has to be developed and qualified for nuclear use. This paper gives a brief overview of various materials that are essential to establish advanced systems feasibility and performance for in pile and out of pile applications, such as ferritic/martensitic steels (9-12% Cr), nickel based alloys (Haynes 230, Inconel 617, etc.), oxide dispersion strengthened ferritic/martensitic steels, and ceramics (SiC, TiC, etc.). This article gives also an insight into the various natures of R&D needed on advanced materials, including fundamental research to investigate basic physical and chemical phenomena occurring in normal and accidental operating conditions, lab-scale tests to characterize candidate materials
4. On Causality in Dynamical Systems
CERN Document Server
Harnack, Daniel
2016-01-01
Identification of causal links is fundamental for the analysis of complex systems. In dynamical systems, however, nonlinear interactions may hamper separability of subsystems which poses a challenge for attempts to determine the directions and strengths of their mutual influences. We found that asymmetric causal influences between parts of a dynamical system lead to characteristic distortions in the mappings between the attractor manifolds reconstructed from respective local observables. These distortions can be measured in a model-free, data-driven manner. This approach extends basic intuitions about cause-effect relations to deterministic dynamical systems and suggests a mathematically well defined explanation of results obtained from previous methods based on state space reconstruction.
5. Chaotic dynamics of controlled electric power systems
Science.gov (United States)
Kozlov, V. N.; Trosko, I. U.
2016-12-01
The conditions for appearance of chaotic dynamics of electromagnetic and electromechanical processes in energy systems described by the Park-Gorev bilinear differential equations with account for lags of coordinates and restrictions on control have been formulated. On the basis of classical equations, the parameters of synchronous generators and power lines, at which the chaotic dynamics of energy systems appears, have been found. The qualitative and quantitative characteristics of chaotic processes in energy associations of two types, based on the Hopf theorem, and methods of nonstationary linearization and decompositions are given. The properties of spectral characteristics of chaotic processes have been investigated, and the qualitative similarity of bilinear equations of power systems and Lorentz equations have been found. These results can be used for modernization of the systems of control of energy objects. The qualitative and quantitative characteristics for power energy systems as objects of control and for some laws of control with the feedback have been established.
6. An individual-based model of Zebrafish population dynamics accounting for energy dynamics
DEFF Research Database (Denmark)
Beaudouin, Remy; Goussen, Benoit; Piccini, Benjamin
2015-01-01
Developing population dynamics models for zebrafish is crucial in order to extrapolate from toxicity data measured at the organism level to biological levels relevant to support and enhance ecological risk assessment. To achieve this, a dynamic energy budget for individual zebrafish (DEB model......, the predictions of the DEB-IBM were compared to existing observations on natural zebrafish populations and the predicted population dynamics are realistic. While our zebrafish DEB-IBM model can still be improved by acquiring new experimental data on the most uncertain processes (e.g. survival or feeding), it can...
7. Ergodic theory and dynamical systems
CERN Document Server
Coudène, Yves
2016-01-01
This textbook is a self-contained and easy-to-read introduction to ergodic theory and the theory of dynamical systems, with a particular emphasis on chaotic dynamics. This book contains a broad selection of topics and explores the fundamental ideas of the subject. Starting with basic notions such as ergodicity, mixing, and isomorphisms of dynamical systems, the book then focuses on several chaotic transformations with hyperbolic dynamics, before moving on to topics such as entropy, information theory, ergodic decomposition and measurable partitions. Detailed explanations are accompanied by numerous examples, including interval maps, Bernoulli shifts, toral endomorphisms, geodesic flow on negatively curved manifolds, Morse-Smale systems, rational maps on the Riemann sphere and strange attractors. Ergodic Theory and Dynamical Systems will appeal to graduate students as well as researchers looking for an introduction to the subject. While gentle on the beginning student, the book also contains a number of commen...
8. An individual-based model of zebrafish population dynamics accounting for energy dynamics.
Directory of Open Access Journals (Sweden)
Rémy Beaudouin
Full Text Available Developing population dynamics models for zebrafish is crucial in order to extrapolate from toxicity data measured at the organism level to biological levels relevant to support and enhance ecological risk assessment. To achieve this, a dynamic energy budget for individual zebrafish (DEB model was coupled to an individual based model of zebrafish population dynamics (IBM model. Next, we fitted the DEB model to new experimental data on zebrafish growth and reproduction thus improving existing models. We further analysed the DEB-model and DEB-IBM using a sensitivity analysis. Finally, the predictions of the DEB-IBM were compared to existing observations on natural zebrafish populations and the predicted population dynamics are realistic. While our zebrafish DEB-IBM model can still be improved by acquiring new experimental data on the most uncertain processes (e.g. survival or feeding, it can already serve to predict the impact of compounds at the population level.
9. PERANCANGAN DAN PENERAPAN MATERIAL FLOW COST ACCOUNTING UNTUK PENINGKATAN KEBERLANJUTAN PERUSAHAAN PT XYZ
Directory of Open Access Journals (Sweden)
Rochman Marota
2015-07-01
Full Text Available This research aimed to answer the questions of sustainability of palm oil processing PT XYZ in the economic, social, environmental and technology with the design and implementation of Material Flow Cost Accounting (MFCA. MFCA provides open information about the classification of production costs, with special attention to the cost of material loss and production waste. The goal is efficiency and effectiveness of production cost which can increase the performance of the production process as well as providing an influence on the value of corporate sustainability. The method used in this research was a mixture of qualitative and quantitative method. Measuring tool used multiple regression analysis to measure the significance of independent variables on the dependent variables. As additional analyses used Multidimensional Scaling (MDS method with rapMFCA techniques and Analytical Hierarchy Process (AHP method with a pairwise comparison technique for assessed corporate sustainability indexes for every dimension and weight combined. The analysis showed that the MFCA provides significant effect as the results of the F test, t test and probability test. The results obtained with this technique showed that the value of sustainability index after merging weight is 85,33 and is in the category of highly sustainable. From these results the performance formulation formulated suggestions for maintaining the stability of the production process of corporate sustainability indexes.Keywords: corporate sustainability, efficiency and effectiveness of production cost, material flow cost accounting, production process performancABSTRAKPenelitian ini berusaha menjawab permasalahan keberlanjutan perusahaan pengolahan kelapa sawit PT XYZ dalam dimensi ekonomi, sosial, lingkungan dan teknologi dengan perancangan dan penerapan Material Flow Cost Accounting (MFCA. MFCA memberikan informasi terbuka tentang klasifikasi biaya produksi, dengan perhatian khusus kepada
10. Dynamical systems in classical mechanics
CERN Document Server
Kozlov, V V
1995-01-01
This book shows that the phenomenon of integrability is related not only to Hamiltonian systems, but also to a wider variety of systems having invariant measures that often arise in nonholonomic mechanics. Each paper presents unique ideas and original approaches to various mathematical problems related to integrability, stability, and chaos in classical dynamics. Topics include… the inverse Lyapunov theorem on stability of equilibria geometrical aspects of Hamiltonian mechanics from a hydrodynamic perspective current unsolved problems in the dynamical systems approach to classical mechanics
11. Classical dynamics of particles and systems
CERN Document Server
Marion, Jerry B
1965-01-01
Classical Dynamics of Particles and Systems presents a modern and reasonably complete account of the classical mechanics of particles, systems of particles, and rigid bodies for physics students at the advanced undergraduate level. The book aims to present a modern treatment of classical mechanical systems in such a way that the transition to the quantum theory of physics can be made with the least possible difficulty; to acquaint the student with new mathematical techniques and provide sufficient practice in solving problems; and to impart to the student some degree of sophistication in handl
12. 20 CFR 670.530 - Are Job Corps centers required to maintain a student accountability system?
Science.gov (United States)
2010-04-01
... student accountability system? 670.530 Section 670.530 Employees' Benefits EMPLOYMENT AND TRAINING... accountability system? Yes, each Job Corps center must establish and operate an effective system to account for... student absence. Each center must operate its student accountability system according to requirements...
13. Kuramoto dynamics in Hamiltonian systems.
Science.gov (United States)
Witthaut, Dirk; Timme, Marc
2014-09-01
The Kuramoto model constitutes a paradigmatic model for the dissipative collective dynamics of coupled oscillators, characterizing in particular the emergence of synchrony (phase locking). Here we present a classical Hamiltonian (and thus conservative) system with 2N state variables that in its action-angle representation exactly yields Kuramoto dynamics on N-dimensional invariant manifolds. We show that locking of the phase of one oscillator on a Kuramoto manifold to the average phase emerges where the transverse Hamiltonian action dynamics of that specific oscillator becomes unstable. Moreover, the inverse participation ratio of the Hamiltonian dynamics perturbed off the manifold indicates the global synchronization transition point for finite N more precisely than the standard Kuramoto order parameter. The uncovered Kuramoto dynamics in Hamiltonian systems thus distinctly links dissipative to conservative dynamics.
14. Governance of Aquatic Agricultural Systems: Analyzing Representation, Power, and Accountability
Directory of Open Access Journals (Sweden)
Blake D. Ratner
2013-12-01
Full Text Available Aquatic agricultural systems in developing countries face increasing competition from multiple stakeholders over rights to access and use natural resources, land, water, wetlands, and fisheries, essential to rural livelihoods. A key implication is the need to strengthen governance to enable equitable decision making amidst competition that spans sectors and scales, building capacities for resilience, and for transformations in institutions that perpetuate poverty. In this paper we provide a simple framework to analyze the governance context for aquatic agricultural system development focused on three dimensions: stakeholder representation, distribution of power, and mechanisms of accountability. Case studies from Cambodia, Bangladesh, Malawi/Mozambique, and Solomon Islands illustrate the application of these concepts to fisheries and aquaculture livelihoods in the broader context of intersectoral and cross-scale governance interactions. Comparing these cases, we demonstrate how assessing governance dimensions yields practical insights into opportunities for transforming the institutions that constrain resilience in local livelihoods.
15. IMPACT OF ACCOUNTING INFORMATION SYSTEMS ON INTERNAL AUDITORS IN TURKEY
Directory of Open Access Journals (Sweden)
Ömer Faruk TAN
2016-08-01
Full Text Available The increasing sophistication of technology has opened up the use of accounting information systems (AIS to companies. These systems are important because they enable all levels of management to access comprehensive information that goes into the planning and controlling of activities within business organizations. In addition, AIS provide quality information to internal and external users and typically cover six main aspects: people, procedures, data, software, information technology infrastructure, and internal controls. This study uses a questionnaire survey to examine the influence of AIS on internal auditors in Turkey. AIS are vital for internal auditors because they process the transactions, that is, they maintain financial records. It is, to the best of my knowledge, the first study to do so. In all, I put 12 questions and 106 internal auditors were agreed to participate the survey and found that internal auditors in Turkey believe that AIS contribute positively to their work.
16. Business Intelligence Systems Accounting Integration in Romania. a Comparative Analysis
Directory of Open Access Journals (Sweden)
Daniela Postolache (Males
2010-12-01
Full Text Available Business Intelligence (BI systems have penetrated the Romanian market, providing a real decision support by integrating and synthesizing a large variety of information available in real time, anywhere in the world, including through mobile terminals. This study examines the BI solutions promoted in Romania through Internet sites written in Romanian, in terms of how the accounting information integration is done. Our paper highlights the most used economic and financial indicators and most often selected tools by BI systems developers to assist decisions. The writing bring forward the lack of transparency of the analyzed sites towards of configuration details of economic instruments, which we consider likely to delay the managers from Romania in order to become familiar with BI solutions, and it represent a weakness of this products promotion.
17. Reasoning about Dynamic Normative Systems
NARCIS (Netherlands)
Knobbout, Max; Dastani, Mehdi; Meyer, John-Jules Charles
2014-01-01
The use of normative systems is widely accepted as an effective approach to control and regulate the behaviour of agents in multiagent systems. When norms are added to a normative system, the behaviour of such a system changes. As of yet, there is no clear formal methodology to model the dynamics of
18. Dynamic Systems and Software
DEFF Research Database (Denmark)
Thomsen, Per Grove
1996-01-01
A one-dimensional model with axial discretization of engine components has been formulated using tha balance equations for mass energy and momentum and the ideal gas equation of state. ODE's that govern the dynamic behaviour of the regenerator matrix temperatures are included in the model. Known ...
19. Dynamic Systems and Software
DEFF Research Database (Denmark)
Thomsen, Per Grove
1996-01-01
A one-dimensional model with axial discretization of engine components has been formulated using tha balance equations for mass energy and momentum and the ideal gas equation of state. ODE's that govern the dynamic behaviour of the regenerator matrix temperatures are included in the model. Known...
20. Permutation Complexity in Dynamical Systems
CERN Document Server
Amigo, Jose
2010-01-01
The study of permutation complexity can be envisioned as a new kind of symbolic dynamics whose basic blocks are ordinal patterns, that is, permutations defined by the order relations among points in the orbits of dynamical systems. Since its inception in 2002 the concept of permutation entropy has sparked a new branch of research in particular regarding the time series analysis of dynamical systems that capitalizes on the order structure of the state space. Indeed, on one hand ordinal patterns and periodic points are closely related, yet ordinal patterns are amenable to numerical methods, while periodicity is not. Another interesting feature is that since it can be shown that random (unconstrained) dynamics has no forbidden patterns with probability one, their existence can be used as a fingerprint to identify any deterministic origin of orbit generation. This book is primarily addressed to researchers working in the field of nonlinear dynamics and complex systems, yet will also be suitable for graduate stude...
1. Thickness effect in the statics and dynamics of wetting on soft materials
Science.gov (United States)
Zhao, Menghua; Roche, Matthieu; Dervaux, Julien; Royon, Laurent; Narita, Tetsuharu; Lequeux, François; Limat, Laurent; Matière et Systèmes Complexes-UMR 7057 Team; Sciences et Ingénierie de la Matière Molle-UMR 7615 Team
2016-11-01
The wetting of liquids on soft materials such as elastomers has received a great deal of attention in the past decades. Many experiments were performed to gain insight into both the statics and dynamics of wetting in such systems, but most neglected the effect of finite thickness of the gel. Here we report results of a study of the thickness effect on both the statics and dynamics of wetting. We vary the thickness of soft silicone elastomers from 10-2 to a few mm. First, we develop a quantitative Schlieren optics enabling us to observe the surface deformation after the deposition of droplets. We measure the vertical deformation outside droplets as a function of droplet size, gel thickness and elasticity. We identify a submicrometer-deep dimple, that extends over mm away from the contact line. Second, we characterize the receding dynamics and we show that the dynamic contact angle, hence dissipation, depends on the thickness of the sample. We rationalize our experiments, with an analytical model accounting for the linear elastic response of the gel bulk and its surface tension. We find excellent agreement with experiments.
2. Evaluating accounting information systems that support multiple GAAP reporting using Normalized Systems Theory
NARCIS (Netherlands)
Vanhoof, E.; Huysmans, P.; Aerts, Walter; Verelst, J.; Aveiro, D.; Tribolet, J.; Gouveia, D.
2014-01-01
This paper uses a mixed methods approach of design science and case study research to evaluate structures of Accounting Information Systems (AIS) that report in multiple Generally Accepted Accounting Principles (GAAP), using Normalized Systems Theory (NST). To comply with regulation, many companies
3. Accounting for exhaust gas transport dynamics in instantaneous emission models via smooth transition regression.
Science.gov (United States)
Kamarianakis, Yiannis; Gao, H Oliver
2010-02-15
Collecting and analyzing high frequency emission measurements has become very usual during the past decade as significantly more information with respect to formation conditions can be collected than from regulated bag measurements. A challenging issue for researchers is the accurate time-alignment between tailpipe measurements and engine operating variables. An alignment procedure should take into account both the reaction time of the analyzers and the dynamics of gas transport in the exhaust and measurement systems. This paper discusses a statistical modeling framework that compensates for variable exhaust transport delay while relating tailpipe measurements with engine operating covariates. Specifically it is shown that some variants of the smooth transition regression model allow for transport delays that vary smoothly as functions of the exhaust flow rate. These functions are characterized by a pair of coefficients that can be estimated via a least-squares procedure. The proposed models can be adapted to encompass inherent nonlinearities that were implicit in previous instantaneous emissions modeling efforts. This article describes the methodology and presents an illustrative application which uses data collected from a diesel bus under real-world driving conditions.
4. USE OF STATISTICAL METHODS IN DETECTING ACCOUNTING ENGINEERING ACTIVITIES (AS EXEMPLIFIED BY THE ACCOUNTING SYSTEM IN POLAND – FIRST PART: THEOTHEORETICAL
Directory of Open Access Journals (Sweden)
Leszek Michalczyk
2013-05-01
Full Text Available This article is one in a series of two publications concerning companies’ detection of accounting engineering operations in use. Its conclusions and methods may be applied to external auditing procedures. The aim of the present duo-article is to define a method of statistical analysis that could identify procedures falling within the scope of a framework herein defined as accounting engineering. This model for analysis is meant to be employed in these aspects of initial financial and accounting audit in a business enterprise that have to do with isolating the influence of variant accounting solutions, which are a consequence of the settlement method chosen by the enterprise. Materials for statistical analysis were divided into groups according to the field in which a given company operated. In this article, we accept and elaborate on the premise that significant differences in financial results may be solely a result of either expansive policy on new markets or the acquisition of cheaper sources for operating activities. In the remaining cases, the choice of valuation and settlement methods becomes crucial; the greater the deviations, the more essential this choice becomes. Even though the research materials we analyze are regionally-conditioned, the model may find its application in other accounting systems in the country, provided that it has been appropriately implemented. Furthermore, the article defines an innovative concept of variant accounting.
5. USE OF STATISTICAL METHODS IN DETECTING ACCOUNTING ENGINEERING ACTIVITIES (AS EXEMPLIFIED BY THE ACCOUNTING SYSTEM IN POLAND – SECOND PART: EMPIRICAL ASPECTS OF ANALYSIS
Directory of Open Access Journals (Sweden)
Leszek Michalczyk
2013-10-01
Full Text Available This article is one in a series of two publications concerning detection of accounting engineering operations in use. Its conclusions and methods may be applied to external auditing procedures. The aim of the present duo-article is to define a method of statistical analysis that could identify procedures falling within the scope of a framework herein defined as accounting engineering. This model for analysis is meant to be employed in these aspects of initial financial and accounting audit in a business enterprise that have to do with isolating the influence of variant accounting solutions, which are a consequence of the settlement method chosen by the enterprise. Materials for statistical analysis were divided into groups according to the field in which a given company operated. In this article, we accept and elaborate on the premise that significant differences in financial results may be solely a result of either expansive policy on new markets or the acquisition of cheaper sources for operating activities. In the remaining cases, the choice of valuation and settlement methods becomes crucial; the greater the deviations, the more essential this choice becomes. Even though the research materials we analyze are regionally-conditioned, the model may find its application in other accounting systems, provided that it has been appropriately implemented. Furthermore, the article defines an innovative concept of variant accounting.
6. CONSIDERATIONS ON THE TREATMENT OF QUALITATIVE CHARACTERISTICS OF ACCOUNTING INFORMATION AT THE INTERNATIONAL LEVEL AND IN VARIOUS NATIONAL ACCOUNTING SYSTEMS
Directory of Open Access Journals (Sweden)
Ionela Cristina Breahna Pravat
2014-07-01
Full Text Available The qualitative characteristics of accounting information presented by financial-accounting reports represent a concept which was subsequently introduced in the national legal accounting framework and, as a rule, the national conceptual frameworks represent the documents by means of which these quality criteria are established. At a worldwide level, there are more international or national organisms that have an important role in the elaboration of accounting standards in general and more specifically in the formulation of qualitative characteristics of financial reporting. We find two important ones among them, and these are: International Accounting Standards Board, which creates and promotes International Financial Reporting Standards (IFRS, and Financial Accounting Standards Board, which elaborates Generally Accepted Accounting Principles (US GAAP. However, at the level of each country a standardizing authority decides the rules for producing the financial reports and the qualitative characteristics that must be respected by the information contained in these documents. In this context, this paper aims to present a few general considerations concerning the treatment of the qualitative characteristics of the financial-accounting information in different accounting systems, such as the American one, or the British, French, German, Romanian ones, with insistence on the international approach to qualitative characteristics.
7. Gas bubble dynamics in soft materials.
Science.gov (United States)
Solano-Altamirano, J M; Malcolm, John D; Goldman, Saul
2015-01-01
Epstein and Plesset's seminal work on the rate of gas bubble dissolution and growth in a simple liquid is generalized to render it applicable to a gas bubble embedded in a soft elastic solid. Both the underlying diffusion equation and the expression for the gas bubble pressure were modified to allow for the non-zero shear modulus of the medium. The extension of the diffusion equation results in a trivial shift (by an additive constant) in the value of the diffusion coefficient, and does not change the form of the rate equations. But the use of a generalized Young-Laplace equation for the bubble pressure resulted in significant differences on the dynamics of bubble dissolution and growth, relative to an inviscid liquid medium. Depending on whether the salient parameters (solute concentration, initial bubble radius, surface tension, and shear modulus) lead to bubble growth or dissolution, the effect of allowing for a non-zero shear modulus in the generalized Young-Laplace equation is to speed up the rate of bubble growth, or to reduce the rate of bubble dissolution, respectively. The relation to previous work on visco-elastic materials is discussed, as is the connection of this work to the problem of Decompression Sickness (specifically, "the bends"). Examples of tissues to which our expressions can be applied are provided. Also, a new phenomenon is predicted whereby, for some parameter values, a bubble can be metastable and persist for long times, or it may grow, when embedded in a homogeneous under-saturated soft elastic medium.
8. Are allogenic or xenogenic screws and plates a reasonable alternative to alloplastic material for osteosynthesis--a histomorphological analysis in a dynamic system.
Science.gov (United States)
Jacobsen, C; Obwegeser, J A
2010-12-01
Despite invention of titanium and resorbable screws and plates, still, one of the main challenges in bone fixation is the search for an ideal osteosynthetic material. Biomechanical properties, biocompatibility, and also cost effectiveness and clinical practicability are factors for the selection of a particular material. A promising alternative seems to be screws and plates made of bone. Recently, xenogenic bone pins and screws have been invented for use in joint surgery. In this study, screws made of allogenic sheep and xenogenic human bone were analyzed in a vital and dynamic sheep-model and compared to conventional titanium screws over a standard period of bone healing of 56 days with a constant applied extrusion force. Biomechanical analysis and histomorphological evaluation were performed. After 56 days of insertion xenogenic screws made of human bone showed significantly larger distance of extrusion of on average 173.8 μm compared to allogenic screws made of sheep bone of on average 27.8 and 29.95 μm of the titanium control group. Severe resorption processes with connective tissue interposition were found in the histomorphological analysis of the xenogenic screws in contrast to new bone formation and centripetal vascularization of the allogenic bone screw, as well as in processes of incorporation of the titanium control group. The study showed allogenic cortical bone screws as a substantial alternative to titanium screws with good biomechanical properties. In contrast to other reports a different result was shown for the xenogenic bone screws. They showed insufficient holding strength with confirmative histomorphological signs of degradation and insufficient osseointegration. Before common clinical use of xenogenic osteosynthetic material, further evaluation should be performed.
9. Environmental farm accounting: the case of the Dutch nutrients accounting system.
NARCIS (Netherlands)
Breembroek, J.A.; Koole, B.; Poppe, K.J.; Wossink, G.A.A.
1996-01-01
In the Netherlands bookkeeping of inputs and outputs at the level of individual farms has been selected as a new solution to control nutrient use and to tax nutrient surpluses in agriculture. At the same time, nutrient accounting presents important management information. This paper presents a theor
10. Controls Over the Computerized Accounts Payble System at Defense Finance and Accounting Service Kansas City
Science.gov (United States)
2007-11-02
Certify All 2 All1 Accessible2 All All Accessible Citibank3 5 All Accessible All None None Citibank Lead 1 Inquiry4 None Inquiry Inquiry Accessible...The Citibank profile allows technicians to enter information related to credit card accounts. 4. �Inquiry� means that the function can only be
11. Environmental farm accounting: the case of the Dutch nutrients accounting system.
NARCIS (Netherlands)
Breembroek, J.A.; Koole, B.; Poppe, K.J.; Wossink, G.A.A.
1996-01-01
In the Netherlands bookkeeping of inputs and outputs at the level of individual farms has been selected as a new solution to control nutrient use and to tax nutrient surpluses in agriculture. At the same time, nutrient accounting presents important management information. This paper presents a
12. Approximate reduction of dynamical systems
CERN Document Server
Tabuada, Paulo; Julius, Agung; Pappas, George J
2007-01-01
The reduction of dynamical systems has a rich history, with many important applications related to stability, control and verification. Reduction of nonlinear systems is typically performed in an exact manner - as is the case with mechanical systems with symmetry--which, unfortunately, limits the type of systems to which it can be applied. The goal of this paper is to consider a more general form of reduction, termed approximate reduction, in order to extend the class of systems that can be reduced. Using notions related to incremental stability, we give conditions on when a dynamical system can be projected to a lower dimensional space while providing hard bounds on the induced errors, i.e., when it is behaviorally similar to a dynamical system on a lower dimensional space. These concepts are illustrated on a series of examples.
13. Ignition probability of polymer-bonded explosives accounting for multiple sources of material stochasticity
Energy Technology Data Exchange (ETDEWEB)
Kim, S.; Barua, A.; Zhou, M., E-mail: [email protected] [The George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0405 (United States); Horie, Y. [Air Force Research Lab, Munitions Directorate, 2306 Perimeter Road, Eglin AFB, Florida 32542 (United States)
2014-05-07
Accounting for the combined effect of multiple sources of stochasticity in material attributes, we develop an approach that computationally predicts the probability of ignition of polymer-bonded explosives (PBXs) under impact loading. The probabilistic nature of the specific ignition processes is assumed to arise from two sources of stochasticity. The first source involves random variations in material microstructural morphology; the second source involves random fluctuations in grain-binder interfacial bonding strength. The effect of the first source of stochasticity is analyzed with multiple sets of statistically similar microstructures and constant interfacial bonding strength. Subsequently, each of the microstructures in the multiple sets is assigned multiple instantiations of randomly varying grain-binder interfacial strengths to analyze the effect of the second source of stochasticity. Critical hotspot size-temperature states reaching the threshold for ignition are calculated through finite element simulations that explicitly account for microstructure and bulk and interfacial dissipation to quantify the time to criticality (t{sub c}) of individual samples, allowing the probability distribution of the time to criticality that results from each source of stochastic variation for a material to be analyzed. Two probability superposition models are considered to combine the effects of the multiple sources of stochasticity. The first is a parallel and series combination model, and the second is a nested probability function model. Results show that the nested Weibull distribution provides an accurate description of the combined ignition probability. The approach developed here represents a general framework for analyzing the stochasticity in the material behavior that arises out of multiple types of uncertainty associated with the structure, design, synthesis and processing of materials.
14. The Role of Ontologies for Designing Accounting Information Systems
Directory of Open Access Journals (Sweden)
Gheorghe NEGOESCU
2010-08-01
Full Text Available The accounting ontologies were conceptualized as a framework for building accounting information systems in a shared data environment, within enterprises or between different enterprises. The model’s base feature was an object pattern consisting of two mirror-image that represented conceptual the input and output components of a business process. The REA acronym derives from that pattern’s structure, whichconsisted of economic resources, economic events, and economic agents. The REA model was proposed as a means for an organization to capture the signification of economic exchanges between two business partners. The REA ontology provides an alternative for modelling an enterprise’s economic resources, economic events, economic agents, andtheir relationships. Resources are considerate organization assets that are able to generate revenue for implicated parties. Events provide a source of detailed data in this approach. Agents participate in events and can affect some resources. They can be anindividual or organization inside or outside the organization that is capable of controlling economic resources and interacting with other agents. The objective of this work is to offer an understandable of this framework and to explain how this model can help us via the identification of the afferent concepts.
15. Lectures on chaotic dynamical systems
CERN Document Server
Afraimovich, Valentin
2002-01-01
This book is devoted to chaotic nonlinear dynamics. It presents a consistent, up-to-date introduction to the field of strange attractors, hyperbolic repellers, and nonlocal bifurcations. The authors keep the highest possible level of "physical" intuition while staying mathematically rigorous. In addition, they explain a variety of important nonstandard algorithms and problems involving the computation of chaotic dynamics. The book will help readers who are not familiar with nonlinear dynamics to understand and appreciate sophisticated modern dynamical systems and chaos. Intended for courses in either mathematics, physics, or engineering, prerequisites are calculus, differential equations, and functional analysis.
16. DRG systems in Europe: variations in cost accounting systems among 12 countries.
Science.gov (United States)
Tan, Siok Swan; Geissler, Alexander; Serdén, Lisbeth; Heurgren, Mona; van Ineveld, B Martin; Redekop, W Ken; Hakkaart-van Roijen, Leona
2014-12-01
Diagnosis-related group (DRG)-based hospital payment systems have gradually become the principal means of reimbursing hospitals in many European countries. Owing to the absence or inaccuracy of costs related to DRGs, these countries have started to routinely collect cost accounting data. The aim of the present article was to compare the cost accounting systems of 12 European countries. A standardized questionnaire was developed to guide comprehensive cost accounting system descriptions for each of the 12 participating countries. The cost accounting systems of European countries vary widely by the share of hospital costs reimbursed through DRG payment, the presence of mandatory cost accounting and/or costing guidelines, the share of cost collecting hospitals, costing methods and data checks on reported cost data. Each of these aspects entails a trade-off between accuracy of the cost data and feasibility constraints. Although a 'best' cost accounting system does not exist, our cross-country comparison gives insight into international differences and may help regulatory authorities and hospital managers to identify and improve areas of weakness in their cost accounting systems. Moreover, it may help health policymakers to underpin the development of a cost accounting system. © The Author 2014. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.
17. A simple distributed mechanism for accounting system self-configuration in next-generation charging and billing
NARCIS (Netherlands)
Kuehne, Ralph; Huitema, George; Carle, Georg
2011-01-01
Modern communication systems are becoming increasingly dynamic and complex. In this article a novel mechanism for next generation charging and billing is presented that enables self-configurability for accounting systems consisting of heterogeneous components. The mechanism is required to be simple,
18. A simple distributed mechanism for accounting system self-configuration in next-generation charging and billing
NARCIS (Netherlands)
Kuehne, Ralph; Huitema, George; Carle, Georg
2011-01-01
Modern communication systems are becoming increasingly dynamic and complex. In this article a novel mechanism for next generation charging and billing is presented that enables self-configurability for accounting systems consisting of heterogeneous components. The mechanism is required to be simple,
19. Dynamic Ocean Track System Plus -
Data.gov (United States)
Department of Transportation — Dynamic Ocean Track System Plus (DOTS Plus) is a planning tool implemented at the ZOA, ZAN, and ZNY ARTCCs. It is utilized by Traffic Management Unit (TMU) personnel...
20. THE ACCOUNTING INFORMATIONAL SYSTEM, ESTABLISHED WITHIN THE STATE TREASURY, AN ESSENTIAL ELEMENT IN SUBSTANTIATING DECISIONS
Directory of Open Access Journals (Sweden)
Claudia Nicoleta GUNI
2017-05-01
Full Text Available The exercise of the management functions and relationships at the level of the organizations is achieved through the leadership system (or management. The management system of the group represents the assembly of elements of a decision making nature, organizational, informational, motivational, etc. through which it is ensured a greater effectiveness and a maximum efficiency. In the design and implementation of the management system there must be taken into account the specific elements of each entity, particularly the profile, size and structure of the human resources, material and financial, the position of the entity in the national and international economic context, etc.
1. Quantum Simulation for Open-System Dynamics
Science.gov (United States)
Wang, Dong-Sheng; de Oliveira, Marcos Cesar; Berry, Dominic; Sanders, Barry
2013-03-01
Simulations are essential for predicting and explaining properties of physical and mathematical systems yet so far have been restricted to classical and closed quantum systems. Although forays have been made into open-system quantum simulation, the strict algorithmic aspect has not been explored yet is necessary to account fully for resource consumption to deliver bounded-error answers to computational questions. An open-system quantum simulator would encompass classical and closed-system simulation and also solve outstanding problems concerning, e.g. dynamical phase transitions in non-equilibrium systems, establishing long-range order via dissipation, verifying the simulatability of open-system dynamics on a quantum Turing machine. We construct an efficient autonomous algorithm for designing an efficient quantum circuit to simulate many-body open-system dynamics described by a local Hamiltonian plus decoherence due to separate baths for each particle. The execution time and number of gates for the quantum simulator both scale polynomially with the system size. DSW funded by USARO. MCO funded by AITF and Brazilian agencies CNPq and FAPESP through Instituto Nacional de Ciencia e Tecnologia-Informacao Quantica (INCT-IQ). DWB funded by ARC Future Fellowship (FT100100761). BCS funded by AITF, CIFAR, NSERC and USARO.
2. Sustainable Innovation, Management Accounting and Control Systems, and International Performance
Directory of Open Access Journals (Sweden)
Ernesto Lopez-Valeiras
2015-03-01
Full Text Available This study analyzes how Management Accounting and Control Systems (MACS facilitate the appropriation of the benefits of sustainable innovations in organizations. In particular, this paper examines the moderating role of different types of MACS in the relationships between sustainable innovation and international performance at an organizational level. We collected survey data from 123 Spanish and Portuguese organizations. Partial Least Square was used to analyze the data. Results show that the effect of sustainable innovations on international performance is enhanced by contemporary rather than traditional types of MACS. Overall our findings show that MACS can help managers to develop and monitor organizational activities (e.g., costumer services and distribution activities, which support the appropriation of the potential benefits from sustainable innovation. This paper responds to recent calls for in-depth studies about the organizational mechanism that may enhance the success of sustainable innovation.
3. Natural Resource Accounting Systems and Environmental Policy Modeling
OpenAIRE
Richard Cabe; Johnson, Stanley R
1990-01-01
Natural Resource Accounting (RCA) combines national income and product accounting concepts with analysis of natural resource and environmental issues. This paper considers this approach for the RCA Appraisal required by the Soil and Water Resources Conservation Act. Recent natural resource accounting literature is examined in light of requirements of the RCA Appraisal. The paper provides a critique of the economic content of the Second RCA Appraisal and develops a natural resource accounting ...
4. 14 CFR Sec. 1-2 - Waivers from this system of accounts and reports.
Science.gov (United States)
2010-01-01
... AIR CARRIERS General Accounting Provisions Sec. 1-2 Waivers from this system of accounts and reports. A waiver from any provision of this system of accounts or reports may be made by the BTS upon its... the principles embodied in the provisions of this system of accounts and reports; and the...
5. Calculation of the dynamic air flow resistivity of fibre materials
DEFF Research Database (Denmark)
Tarnow, Viggo
1997-01-01
The acoustic attenuation of acoustic fiber materials is mainly determined by the dynamic resistivity to an oscillating air flow. The dynamic resistance is calculated for a model with geometry close to the geometry of real fibre material. The model constists of parallel cylinders placed randomly. ......-consistent procedure gives the same results as the more complicated procedure based on average over Voronoi cells. Graphs of the dynamic resistivity versus frequency are given for fiber densities and diameters typical for acoustic fiber materials.......The acoustic attenuation of acoustic fiber materials is mainly determined by the dynamic resistivity to an oscillating air flow. The dynamic resistance is calculated for a model with geometry close to the geometry of real fibre material. The model constists of parallel cylinders placed randomly...
6. Dynamical systems in population biology
CERN Document Server
Zhao, Xiao-Qiang
2017-01-01
This research monograph provides an introduction to the theory of nonautonomous semiflows with applications to population dynamics. It develops dynamical system approaches to various evolutionary equations such as difference, ordinary, functional, and partial differential equations, and pays more attention to periodic and almost periodic phenomena. The presentation includes persistence theory, monotone dynamics, periodic and almost periodic semiflows, basic reproduction ratios, traveling waves, and global analysis of prototypical population models in ecology and epidemiology. Research mathematicians working with nonlinear dynamics, particularly those interested in applications to biology, will find this book useful. It may also be used as a textbook or as supplementary reading for a graduate special topics course on the theory and applications of dynamical systems. Dr. Xiao-Qiang Zhao is a University Research Professor at Memorial University of Newfoundland, Canada. His main research interests involve applied...
7. LCA and emergy accounting of aquaculture systems: towards ecological intensification.
Science.gov (United States)
Wilfart, Aurélie; Prudhomme, Jehane; Blancheton, Jean-Paul; Aubin, Joël
2013-05-30
An integrated approach is required to optimise fish farming systems by maximising output while minimising their negative environmental impacts. We developed a holistic approach to assess the environmental performances by combining two methods based on energetic and physical flow analysis. Life Cycle Assessment (LCA) is a normalised method that estimates resource use and potential impacts throughout a product's life cycle. Emergy Accounting (EA) refers the amount of energy directly or indirectly required by a product or a service. The combination of these two methods was used to evaluate the environmental impacts of three contrasting fish-farming systems: a farm producing salmon in a recirculating system (RSF), a semi-extensive polyculture pond (PF1) and an extensive polyculture pond (PF2). The RSF system, with a low feed-conversion ratio (FCR = 0.95), had lower environmental impacts per tonne of live fish produced than did the two pond farms, when the effects on climate change, acidification, total cumulative energy demand, land competition and water dependence were considered. However, RSF was clearly disconnected from the surrounding environment and depended highly on external resources (e.g. nutrients, energy). Ponds adequately incorporated renewable natural resources but had higher environmental impacts due to incomplete use of external inputs. This study highlighted key factors necessary for the successful ecological intensification of fish farming, i.e., minimise external inputs, lower the FCR, and increase the use of renewable resources from the surrounding environment. The combination of LCA and EA seems to be a practical approach to address the complexity of optimising biophysical efficiency in aquaculture systems.
8. Handbook of dynamical systems, v.3
CERN Document Server
Takens, F; Broer, H W
2010-01-01
In this volume, the authors present a collection of surveys on various aspects of the theory of bifurcations of differentiable dynamical systems and related topics. By selecting these subjects, they focus on those developments from which research will be active in the coming years. The surveys are intended to educate the reader on the recent literature on the following subjects: transversality and generic properties like the various forms of the so-called Kupka-Smale theorem, the Closing Lemma and generic local bifurcations of functions (so-called catastrophe theory) and generic local bifurcations in 1-parameter families of dynamical systems, and notions of structural stability and moduli. * Covers recent literature on various topics related to the theory of bifurcations of differentiable dynamical systems* Highlights developments that are the foundation for future research in this field* Provides material in the form of surveys, which are important tools for introducing the bifurcations of differentiable dyn...
9. Structure and dynamics in network-forming materials
Science.gov (United States)
Wilson, Mark
2016-12-01
The study of the structure and dynamics of network-forming materials is reviewed. Experimental techniques used to extract key structural information are briefly considered. Strategies for building simulation models, based on both targeting key (experimentally-accessible) materials and on systematically controlling key model parameters, are discussed. As an example of the first class of materials, a key target system, SiO2, is used to highlight how the changing structure with applied pressure can be effectively modelled (in three dimensions) and used to link to both experimental results and simple structural models. As an example of the second class the topology of networks of tetrahedra in the MX2 stoichiometry are controlled using a single model parameter linked to the M-X-M bond angles. The evolution of ordering on multiple length-scales is observed as are the links between the static structure and key dynamical properties. The isomorphous relationship between the structures of amorphous Si and SiO2 is discussed as are the similarities and differences in the phase diagrams, the latter linked to potential polyamorphic and ‘anomalous’ (e.g. density maxima) behaviour. Links to both two-dimensional structures for C, Si and Ge and near-two-dimensional bilayers of SiO2 are discussed. Emerging low-dimensional structures in low temperature molten carbonates are also uncovered.
10. Smart Materials for Ranging Systems
CERN Document Server
Franse, Jaap; Sirenko, Valentyna
2006-01-01
The problem of determining the location of an object (usually called ranging) attracts at present much attention in different areas of applications, among them in ecological and safety devices. Electromagnetic waves along with sound waves are widely used for these purposes. Different aspects of materials with specific magnetic, electric and elastic properties are considered in view of potential application in the design and manufacturing of smart materials. Progress is reported in the fabrication and understanding of in-situ formation and characterization of solid state structures with specified properties. Attention is paid to the observation and study of the mobility of magnetic structures and of the kinetics of magnetic ordering transitions. Looking from a different perspective, one of the outcomes of the ARW is the emphasis on the important role that collective phenomena (like spin waves in systems with a magnetically ordered ground state, or critical currents in superconductors) could play at the design ...
11. The Reasons of and Countermeasures for the Inventory/Account Inconsistent and Account/Account Inconsistent of Books and Reference Materials in University%高校图书资料账实及账账不符的原因及对策
Institute of Scientific and Technical Information of China (English)
赵联锋
2015-01-01
From the aspects of the management system, account book establishment, and accounting standard, etc. of the books and reference materials, this paper analyzes the main reasons of inventory/account inconsistent and account/account inconsistent, and from the aspects of straightening out the management system of books and reference materials, standardizing the management process of books and reference materials, and recording the value of books and reference materials in account in compliance with relevant laws and regulations, etc., probes into the countermeasures for conducting the good management and use of books and reference materials in university and realizing the the security and integrity of the books and reference materials.%从图书资料的管理体系、账簿设置及入账标准等方面，分析了高校图书资料账实、账账不符的主要原因，并从理顺图书资料管理体系、规范图书资料管理流程、合理合规的图书资料价值入账等方面，探讨了管好用好高校图书资料，实现图书资料安全与完整的对策。
12. Accounting for the Ecological Footprint of Materials in Consumer Goods at the Urban Scale
Directory of Open Access Journals (Sweden)
William E. Rees
2013-05-01
Full Text Available Ecological footprint analysis (EFA can be used by cities to account for their on-going demands on global renewable resources. To date, EFA has not been fully implemented as an urban policy and planning tool in part due to limitations of local data availability. In this paper we focus on the material consumption component of the urban ecological footprint and identify the ‘component, solid waste life cycle assessment approach’ as one that overcomes data limitations by using data many cities regularly collect: municipal, solid waste composition data which serves as a proxy for material consumption. The approach requires energy use and/or carbon dioxide emissions data from process LCA studies as well as agricultural and forest land data for calculation of a material’s ecological footprint conversion value. We reviewed the process LCA literature for twelve materials commonly consumed in cities and determined ecological footprint conversion values for each. We found a limited number of original LCA studies but were able to generate a range of values for each material. Our set of values highlights the importance for cities to identify both the quantities consumed and per unit production impacts of a material. Some materials like textiles and aluminum have high ecological footprints but make up relatively smaller proportions of urban waste streams than products like paper and diapers. Local government use of the solid waste LCA approach helps to clearly identify the ecological loads associated with the waste they manage on behalf of their residents. This direct connection can be used to communicate to citizens about stewardship, recycling and ecologically responsible consumption choices that contribute to urban sustainability.
13. Dynamical simulations of strongly correlated electron materials
Science.gov (United States)
Kress, Joel; Barros, Kipton; Batista, Cristian; Chern, Gia-Wei; Kotliar, Gabriel
We present a formulation of quantum molecular dynamics that includes electron correlation effects via the Gutzwiller method. Our new scheme enables the study of the dynamical behavior of atoms and molecules with strong electron interactions. The Gutzwiller approach goes beyond the conventional mean-field treatment of the intra-atomic electron repulsion and captures crucial correlation effects such as band narrowing and electron localization. We use Gutzwiller quantum molecular dynamics to investigate the Mott transition in the liquid phase of a single-band metal and uncover intriguing structural and transport properties of the atoms.
14. Topic: Catchment system dynamics: Processes and feedbacks
Science.gov (United States)
2015-04-01
In this meeting we can talk about my main expertise: the focus of my research ocus revolves around understanding catchment system dynamics in a holistic way by incorporating both processes on hillslopes as well as in the river channel. Process knowledge enables explanation of the impact of natural and human drivers on the catchment systems and which consequences these drivers have for water and sediment connectivity. Improved understanding of the catchment sediment and water dynamics will empower sustainable land and river management and mitigate soil threats like erosion and off-side water and sediment accumulation with the help of nature's forces. To be able to understand the system dynamics of a catchment, you need to study the catchment system in a holistic way. In many studies only the hillslopes or even plots are studied; or only the channel. However, these systems are connected and should be evaluated together. When studying a catchment system any intervention to the system will create both on- as well as off sites effects, which should especially be taken into account when transferring science into policy regulations or management decisions.
15. Nonlinear dynamics in biological systems
CERN Document Server
Carballido-Landeira, Jorge
2016-01-01
This book presents recent research results relating to applications of nonlinear dynamics, focusing specifically on four topics of wide interest: heart dynamics, DNA/RNA, cell mobility, and proteins. The book derives from the First BCAM Workshop on Nonlinear Dynamics in Biological Systems, held in June 2014 at the Basque Center of Applied Mathematics (BCAM). At this international meeting, researchers from different but complementary backgrounds, including molecular dynamics, physical chemistry, bio-informatics and biophysics, presented their most recent results and discussed the future direction of their studies using theoretical, mathematical modeling and experimental approaches. Such was the level of interest stimulated that the decision was taken to produce this publication, with the organizers of the event acting as editors. All of the contributing authors are researchers working on diverse biological problems that can be approached using nonlinear dynamics. The book will appeal especially to applied math...
16. Self-Supervised Dynamical Systems
Science.gov (United States)
Zak, Michail
2003-01-01
Some progress has been made in a continuing effort to develop mathematical models of the behaviors of multi-agent systems known in biology, economics, and sociology (e.g., systems ranging from single or a few biomolecules to many interacting higher organisms). Living systems can be characterized by nonlinear evolution of probability distributions over different possible choices of the next steps in their motions. One of the main challenges in mathematical modeling of living systems is to distinguish between random walks of purely physical origin (for instance, Brownian motions) and those of biological origin. Following a line of reasoning from prior research, it has been assumed, in the present development, that a biological random walk can be represented by a nonlinear mathematical model that represents coupled mental and motor dynamics incorporating the psychological concept of reflection or self-image. The nonlinear dynamics impart the lifelike ability to behave in ways and to exhibit patterns that depart from thermodynamic equilibrium. Reflection or self-image has traditionally been recognized as a basic element of intelligence. The nonlinear mathematical models of the present development are denoted self-supervised dynamical systems. They include (1) equations of classical dynamics, including random components caused by uncertainties in initial conditions and by Langevin forces, coupled with (2) the corresponding Liouville or Fokker-Planck equations that describe the evolutions of probability densities that represent the uncertainties. The coupling is effected by fictitious information-based forces, denoted supervising forces, composed of probability densities and functionals thereof. The equations of classical mechanics represent motor dynamics that is, dynamics in the traditional sense, signifying Newton s equations of motion. The evolution of the probability densities represents mental dynamics or self-image. Then the interaction between the physical and
17. Towards a dynamic assessment of raw materials criticality: linking agent-based demand--with material flow supply modelling approaches.
Science.gov (United States)
Knoeri, Christof; Wäger, Patrick A; Stamp, Anna; Althaus, Hans-Joerg; Weil, Marcel
2013-09-01
Emerging technologies such as information and communication-, photovoltaic- or battery technologies are expected to increase significantly the demand for scarce metals in the near future. The recently developed methods to evaluate the criticality of mineral raw materials typically provide a 'snapshot' of the criticality of a certain material at one point in time by using static indicators both for supply risk and for the impacts of supply restrictions. While allowing for insights into the mechanisms behind the criticality of raw materials, these methods cannot account for dynamic changes in products and/or activities over time. In this paper we propose a conceptual framework intended to overcome these limitations by including the dynamic interactions between different possible demand and supply configurations. The framework integrates an agent-based behaviour model, where demand emerges from individual agent decisions and interaction, into a dynamic material flow model, representing the materials' stocks and flows. Within the framework, the environmental implications of substitution decisions are evaluated by applying life-cycle assessment methodology. The approach makes a first step towards a dynamic criticality assessment and will enhance the understanding of industrial substitution decisions and environmental implications related to critical metals. We discuss the potential and limitation of such an approach in contrast to state-of-the-art methods and how it might lead to criticality assessments tailored to the specific circumstances of single industrial sectors or individual companies. Copyright © 2013 Elsevier B.V. All rights reserved.
Directory of Open Access Journals (Sweden)
Zhukov Aleksey Dmitrievich
2012-10-01
Full Text Available The proposed multi-component façade system is made of porous concretes employed both as bearing structures and for heat insulation and fireproofing purposes. The authors also provide their recommendations in respect of the mounting of the proposed façade system. The façade system considered in the article is composed of wall foam concrete blocks reinforced by basalt fibers (bearing elements of the structure, cellular concrete polystyrene (thermal insulation, and porous concrete (fireproofing and thermal insulation. Retained shuttering (in the fireproofing sections represents chrysolite cement sheets attached to the structures composed of glass-fiber plastic elements. The application of insulating porous concrete as a fireproofing material is based on the principle of adjustable stress-strained states of materials in the environment of variable pressure. This technology was developed at Moscow State University of Civil Engineering, and it was initially designated for the manufacturing of tailor-made products. The above concrete is also designated for retained shuttering and modified cavity masonry walls. Porous concrete that expands inside the fireproofing cavity ensures a tight contact both with the basic material and thermal insulation plates. The use of materials of the same origin (Portland cement means the formation of strong transition zones connecting the system components in the course of its hardening and further operation. The results of the thermotechnical calculation demonstrate that the thermal resistance registered on the surface of the wall that is 3 meters high (that has a 0.4 m fireproofing cavity is equal to 3.98 sq. m. C/Wt. The value of the coefficient of thermotechnical heterogeneity (r is equal to 0.86 with account for the thickness and thermal conductivity of point and linear elements. If the thermotechnical heterogeneity is taken into consideration, the thermal resistance of the proposed wall is equal to 3.42 m2 С/Wt.
19. Nonnegative and Compartmental Dynamical Systems
CERN Document Server
2010-01-01
This comprehensive book provides the first unified framework for stability and dissipativity analysis and control design for nonnegative and compartmental dynamical systems, which play a key role in a wide range of fields, including engineering, thermal sciences, biology, ecology, economics, genetics, chemistry, medicine, and sociology. Using the highest standards of exposition and rigor, the authors explain these systems and advance the state of the art in their analysis and active control design. Nonnegative and Compartmental Dynamical Systems presents the most complete treatment available o
20. Dynamical system approach to phyllotaxis
DEFF Research Database (Denmark)
D'ovidio, Francesco; Mosekilde, Erik
2000-01-01
and not a dynamical system, mainly because new active elements are added at each step, and thus the dimension of the "natural" phase space is not conserved. Here a construction is presented by which a well defined dynamical system can be obtained, and a bifurcation analysis can be carried out. Stable and unstable...... of the Jacobian, and thus the eigenvalues, is given. It is likely that problems of the above type often arise in biology, and especially in morphogenesis, where growing systems are modeled....
1. Dynamically reconfigurable photovoltaic system
Energy Technology Data Exchange (ETDEWEB)
Okandan, Murat; Nielson, Gregory N.
2016-12-27
A PV system composed of sub-arrays, each having a group of PV cells that are electrically connected to each other. A power management circuit for each sub-array has a communications interface and serves to connect or disconnect the sub-array to a programmable power grid. The power grid has bus rows and bus columns. A bus management circuit is positioned at a respective junction of a bus column and a bus row and is programmable through its communication interface to connect or disconnect a power path in the grid. As a result, selected sub-arrays are connected by selected power paths to be in parallel so as to produce a low system voltage, and, alternately in series so as to produce a high system voltage that is greater than the low voltage by at least a factor of ten.
2. Charge carrier dynamics in photovoltaic materials
NARCIS (Netherlands)
Jensen, S.A.
2014-01-01
We employ the experimental technique THz Time Domain spectroscopy (THz-TDS) to study the optoelectronic properties of potential photovoltaic materials. This all-optical method is useful for probing photoconductivities in a range of materials on ultrafast timescales without the application of physica
3. Experimental Modeling of Dynamic Systems
DEFF Research Database (Denmark)
Knudsen, Morten Haack
2006-01-01
An engineering course, Simulation and Experimental Modeling, has been developed that is based on a method for direct estimation of physical parameters in dynamic systems. Compared with classical system identification, the method appears to be easier to understand, apply, and combine with physical...
4. Dynamic probabilistic systems
CERN Document Server
Howard, Ronald A
2007-01-01
This book is an integrated work published in two volumes. The first volume treats the basic Markov process and its variants; the second, semi-Markov and decision processes. Its intent is to equip readers to formulate, analyze, and evaluate simple and advanced Markov models of systems, ranging from genetics and space engineering to marketing. More than a collection of techniques, it constitutes a guide to the consistent application of the fundamental principles of probability and linear system theory.Author Ronald A. Howard, Professor of Management Science and Engineering at Stanford University
5. Parametric Resonance in Dynamical Systems
CERN Document Server
Nijmeijer, Henk
2012-01-01
Parametric Resonance in Dynamical Systems discusses the phenomenon of parametric resonance and its occurrence in mechanical systems,vehicles, motorcycles, aircraft and marine craft, and micro-electro-mechanical systems. The contributors provide an introduction to the root causes of this phenomenon and its mathematical equivalent, the Mathieu-Hill equation. Also included is a discussion of how parametric resonance occurs on ships and offshore systems and its frequency in mechanical and electrical systems. This book also: Presents the theory and principles behind parametric resonance Provides a unique collection of the different fields where parametric resonance appears including ships and offshore structures, automotive vehicles and mechanical systems Discusses ways to combat, cope with and prevent parametric resonance including passive design measures and active control methods Parametric Resonance in Dynamical Systems is ideal for researchers and mechanical engineers working in application fields such as MEM...
6. THE INFLUENCE OF ACCOUNTING SYSTEM AND FISCAL POLICY ON REGIONAL DEVELOPMENT
Directory of Open Access Journals (Sweden)
Oana Bogdan
2014-10-01
Full Text Available Regional development is a concept that aims at stimulating and diversifying economic activities, stimulating private sector investment and it contributes to reducing unemployment and improving living standards. To achieve these goals accounting and tax policies are necessary to allow private operators to realize taxable income, to create jobs for people and to pay taxes and contributions due to the State budget. The State must reinvest a part of the resources collected to the community in order to improve infrastructure, education and health, thus contributing to regional development. Changes in tax law and accounting adopted in Romania during 2009-2014 are regarded as tax breaks for companies created to ensure economic growth, dynamic and sustainable through efficient use of regional and local potential. In this paper we analyze the influence of the accounting and fiscal system on the regional development given that these measures do not always achieve their objectives established companies having benefit from the application of various tax measures. The paper will present the main changes of the tax and accounting systems and their impact on the regional development in Romania and the consequences resulting in implementing these measures.
7. Managing Complex Dynamical Systems
Science.gov (United States)
Cox, John C.; Webster, Robert L.; Curry, Jeanie A.; Hammond, Kevin L.
2011-01-01
Management commonly engages in a variety of research designed to provide insight into the motivation and relationships of individuals, departments, organizations, etc. This paper demonstrates how the application of concepts associated with the analysis of complex systems applied to such data sets can yield enhanced insights for managerial action.
8. Multibody systems and robot dynamics
OpenAIRE
Schiehlen, Werner
1990-01-01
The method of multibody system has been developed during the last two decades with application to various engineering topics, including robotics and walking machines. On the other hand, special algorithms for robot dynamics are available featuring the high computational efficiency required for control purposes. This paper shows the close relation between both approaches. Essential criteria for the effeciency of dynamics software are the numbers of coordinates used, which should be minimal. Fo...
9. Classification framework for partially observed dynamical systems
Science.gov (United States)
Shen, Yuan; Tino, Peter; Tsaneva-Atanasova, Krasimira
2017-04-01
We present a general framework for classifying partially observed dynamical systems based on the idea of learning in the model space. In contrast to the existing approaches using point estimates of model parameters to represent individual data items, we employ posterior distributions over model parameters, thus taking into account in a principled manner the uncertainty due to both the generative (observational and/or dynamic noise) and observation (sampling in time) processes. We evaluate the framework on two test beds: a biological pathway model and a stochastic double-well system. Crucially, we show that the classification performance is not impaired when the model structure used for inferring posterior distributions is much more simple than the observation-generating model structure, provided the reduced-complexity inferential model structure captures the essential characteristics needed for the given classification task.
10. Can a Static Nonlinearity Account for the Dynamics of Otoacoustic Emission Suppression?
Science.gov (United States)
Verhulst, Sarah; Shera, Christopher A.; Harte, James M.; Dau, Torsten
2013-01-01
This study investigates whether time-dependent compression mechanisms in the cochlea are necessary to explain dynamic properties of otoacoustic emissions (OAEs). Dynamic properties of click-evoked OAEs (CEOAEs) have been observed in temporal suppression; the effect where the CEOAE magnitude is reduced when a click is presented less than 10 ms before the test click. A time-domain model of the cochlea that represented the basilar membrane (BM) as a cascade of coupled bandpass filters was used to investigate the cochlear origin of temporal suppression in CEOAEs. The model, implemented with a time-invariant nonlinearity, was able to simulate temporal suppression, but was unable to account for the exact time scale and magnitude of the effect. The results suggest that temporal overlap of BM impulse responses can account for suppression in CEOAEs, but that an additional time-dependent cochlear gain mechanism may be needed to account the high suppression maxima at inter-click intervals larger than zero. PMID:25284908
11. Molecular Dynamics of Materials Possessing High Energy Content.
Science.gov (United States)
1988-01-26
I -RI90 634 MOLECULAR DYNAMICS OF MATERIALS POSSESSING HIGH ENERGY 1/1 r CONTENTCU) COLUMBIA UNIV MENd YORK N J TURRO 26 JAN GO I RFOSR-TR-88-0168...Bolling Air Force Base, D.C. 2 61102F_ 2303 I B2 11 T,TL.E (Inciuoe Security Classification) Molecular Dynamics of Materials Possessing High Energy...York 10027 (212) 280-2175 TITLE: MOLECULAR DYNAMICS OF MATERIALS POSSESSING HIGH ENERGY CONTENT .. 0 0 88 2 ... "" ’% ,i u , . .. .. ....... ŝ" ;! ,i
12. 48 CFR 32.503-3 - Initiation of progress payments and review of accounting system.
Science.gov (United States)
2010-10-01
... payments and review of accounting system. 32.503-3 Section 32.503-3 Federal Acquisition Regulations System... on Costs 32.503-3 Initiation of progress payments and review of accounting system. (a) For..., (2) possessed of an adequate accounting system and controls, and (3) in sound financial...
13. Finite Element Analysis of Layered Fiber Composite Structures Accounting for the Material's Microstructure and Delamination
Science.gov (United States)
Stier, Bertram; Simon, Jaan-Willem; Reese, Stefanie
2015-04-01
The present paper focuses on composite structures which consist of several layers of carbon fiber reinforced plastics (CFRP). For such layered composite structures, delamination constitutes one of the major failure modes. Predicting its initiation is essential for the design of these composites. Evaluating stress-strength relation based onset criteria requires an accurate representation of the through-the-thickness stress distribution, which can be particularly delicate in the case of shell-like structures. Thus, in this paper, a solid-shell finite element formulation is utilized which allows to incorporate a fully three-dimensional material model while still being suitable for applications involving thin structures. Moreover, locking phenomena are cured by using both the EAS and the ANS concept, and numerical efficiency is ensured through reduced integration. The proposed anisotropic material model accounts for the material's micro-structure by using the concept of structural tensors. It is validated by comparison to experimental data as well as by application to numerical examples.
14. Data quality and accounting information systems: Actual performance in Albania
Directory of Open Access Journals (Sweden)
Erjon Zoto
2014-02-01
Full Text Available Data quality is crucial in today’s business processes, as it is generally associated with the set of data fit for use by data consumers - the persons that access, interpret and use data during their work activity. On the other hand, data quality is very important for the Accounting Information Systems’ (AIS success, where AIS is a computer-based system that processes financial data and supports the decision making processes inside the organization. There are empirical evidences showing that data quality level in AIS has been and will always be problematic. Their interrelationship is dependant of several factors, including technical capacities or even the level of teamwork in an organization. This paper tries to analyze the actual performance of the factors influencing in the process of data quality in AIS used from organizations in Albania. The results will be compared with state-of-art literature review regarding the factors perceived as critical factors in ensuring data quality in AIS, giving way to some important concluding remarks.
15. Accounting for the Assimilative Capacity of Water Systems in Scotland
Directory of Open Access Journals (Sweden)
Paula Novo
2017-07-01
Full Text Available A key methodological challenge in understanding the relationship between the economy and the underlying ecosystem base resides in how to account for the ecosystem’s degradation and the decline of associated ecosystem services. In this study, we use information on nutrients and metals concentrations from the Environmental Change Network (ECN database and the Scottish Environment Protection Agency (SEPA for the period 2000–2010 in order to assess the assimilation capacity of water systems. The research covers five upstream sites and 17 downstream sites in northeast Scotland. Our results highlight the relevance of considering a number of pollutants, and suggest that elements such as arsenic, lead and mercury can pose a threat to ecosystems’ sustainability and health. However, little research has been done in terms of their assimilation capacity and their impact on grey water footprint assessments. In addition, the results indicate that background conditions might be relevant when performing sustainability analysis at different spatial scales. The study also poses relevant questions in relation to land management approaches versus traditional ‘end-of-pipe’ water treatment approaches, and the definition of maximum and background concentrations. In this regard, further studies will be required to understand the trade-offs between different ecosystem services depending on how these concentrations are defined.
16. Methods of Analyzing Companies’ Performance in Accounting using Expert Systems
Directory of Open Access Journals (Sweden)
Veronica Grosu
2008-01-01
Full Text Available The company’s performance reflects its capacity of generating future cash-flows, by using existent resources, and the efficiency level in using new resources.The capacity of generating future cash-flows assumes that the company would have to book revenues of its activity, and the use of the existent resources needs a detailed overview of the expenses of the period. The revenues and expenses are elements strictly tied to the evaluation process of the company’s performance. This paper seeks to emphasize the efficiency level in using resources dependent on the profit (when the revenues are higher than the expenses, or on the loss (when the expenses are higher than the revenues, their first-step evaluation in the accounting process, so that the next step would evaluate them through a professional specific processing system, in order to lay out the economic result by efficiently binding the two methods.The current paper will analyze only the recognition and evaluation of companies’ revenues, with the help of the two criteria, when the revenues are higher than the expenses and therefore one will carry out an evaluation and analysis of the company’s performance in this particular field.
17. Job system generation in grid taking into account user preferences
Directory of Open Access Journals (Sweden)
D. M. Yemelyanov
2016-01-01
Full Text Available Distributed computing environments like Grid are characterized by heterogeneity, low cohesion and dynamic structure of computing nodes. This is why the task of resource scheduling in such environments is complex. Different approaches to job scheduling in grid exist. Some of them use economic principles. Economic approaches to scheduling have shown their efficiency. One of such approaches is cyclic scheduling scheme which is considered in this paper.Cyclic scheduling scheme takes into account the preferences of computing environment users by means of an optimization criterion, which is included in the resource request. Besides, the scheme works cyclically by scheduling a certain job batch at each scheduling step. This is why there is a preliminary scheduling step which is job batch generation.The purpose of this study was to estimate the infl uence of job batch structure by the user criterion on the degree of its satisfaction. In other words we had to find the best way to form the batch with relation to the user optimization criterion. For example if it is more efficient to form the batch with jobs with the same criterion value or with different criterion values. Also we wanted to find the combination of criterion values which would give the most efficient scheduling results.To achieve this purpose an experiment in a simulation environment was conducted. The experiment consisted of scheduling of job batches with different values of the user criterion, other parameters of the resource request and the characteristics of the computing environment being the same. Three job batch generation strategies were considered. In the first strategy the batch consisted of jobs with the same criterion value. In the second strategy the batch consisted of jobs with all the considered criteria equally likely. The third strategy was similar to the second one, but only two certain criteria were considered. The third strategy was considered in order to find the most
18. ON COMPLEX DYNAMIC CONTROL SYSTEMS
Institute of Scientific and Technical Information of China (English)
CHENG Daizhan
2003-01-01
This paper presents some recent works on the control of dynamic systems, which have certain complex properties caused by singularity of the nonlinear structures, structure-varyings, or evolution process etc. First, we consider the structure singularity of nonlinear control systems. It was revealed that the focus of researches on nonlinear control theory is shifting from regular systems to singular systems. The singularity of nonlinear systems causes certain complexity. Secondly, the switched systems are considered. For such systems the complexity is caused by the structure varying. We show that the switched systems have significant characteristics of complex systems. Finally, we investigate the evolution systems. The evolution structure makes complexity, and itself is a proper model for complex systems.
19. Quality improvement and accountability in the Danish health care system.
Science.gov (United States)
Mainz, Jan; Kristensen, Solvejg; Bartels, Paul
2015-12-01
Denmark has unique opportunities for quality measurement and benchmarking since Denmark has well-developed health registries and unique patient identifier that allow all registries to include patient-level data and combine data into sophisticated quality performance monitoring. Over decades, Denmark has developed and implemented national quality and patient safety initiatives in the healthcare system in terms of national clinical guidelines, performance and outcome measurement integrated in clinical databases for important diseases and clinical conditions, measurement of patient experiences, reporting of adverse events, national handling of patient complaints, national accreditation and public disclosure of all data on the quality of care. Over the years, Denmark has worked up a progressive and transparent just culture in quality management; the different actors at the different levels of the healthcare system are mutually attentive and responsive in a coordinated effort for quality of the healthcare services. At national, regional, local and hospital level, it is mandatory to participate in the quality initiatives and to use data and results for quality management, quality improvement, transparency in health care and accountability. To further develop the Danish governance model, it is important to expand the model to the primary care sector. Furthermore, a national quality health programme 2015-18 recently launched by the government supports a new development in health care focusing upon delivering high-quality health care-high quality is defined by results of value to the patients. © The Author 2015. Published by Oxford University Press in association with the International Society for Quality in Health Care; all rights reserved.
20. Effect Of The Use Of Information Technology And Organization Cultural Of The Quality Accounting Information System
Directory of Open Access Journals (Sweden)
Bakri
2015-08-01
Full Text Available The result of the application of effective accounting information system and provide quality and effective accounting information quality. Fundamental rule accounting information systems in an organization is generating accounting information quality through the process of collecting raw data and then processed and then presented in the form of accounting information useful for user information. The purpose of this study was to know how the effect of Use of information technology on the quality of accounting information systems organizational culture on the quality of accounting information systems and the quality of accounting information system on the quality of accounting information. Based on the literature of some previous researchers proved that a technology affects the quality of accounting information systems using information system AIS Effectively requires an understanding of the organization management and information technology shaping the system. the use of information technology within an organization intended to provide information to the user. B. Organizational culture affects the quality of AIS at the stage of design and implementation of the system required careful consideration of the information attitude is the main component of the organization information systems can be substantially influenced by the culture of the organization. C accounting information quality influence on information accounting quality is built with the main purpose to process accounting data from various sources into the accounting information needed by a wide range of users to reduce risk when making decisions.
1. Dynamics of quasi-stable dissipative systems
CERN Document Server
Chueshov, Igor
2015-01-01
This book is devoted to background material and recently developed mathematical methods in the study of infinite-dimensional dissipative systems. The theory of such systems is motivated by the long-term goal to establish rigorous mathematical models for turbulent and chaotic phenomena. The aim here is to offer general methods and abstract results pertaining to fundamental dynamical systems properties related to dissipative long-time behavior. The book systematically presents, develops and uses the quasi-stability method while substantially extending it by including for consideration new classes of models and PDE systems arising in Continuum Mechanics. The book can be used as a textbook in dissipative dynamics at the graduate level. Igor Chueshov is a Professor of Mathematics at Karazin Kharkov National University in Kharkov, Ukraine.
2. A Thermodamage Strength Theoretical Model of Ceramic Materials Taking into Account the Effect of Residual Stress
Directory of Open Access Journals (Sweden)
Weiguo Li
2012-01-01
Full Text Available A thermodamage strength theoretical model taking into account the effect of residual stress was established and applied to each temperature phase based on the study of effects of various physical mechanisms on the fracture strength of ultrahigh-temperature ceramics. The effects of SiC particle size, crack size, and SiC particle volume fraction on strength corresponding to different temperatures were studied in detail. This study showed that when flaw size is not large, the bigger SiC particle size results in the greater effect of tensile residual stress in the matrix grains on strength reduction, and this prediction coincides with experimental results; and the residual stress and the combined effort of particle size and crack size play important roles in controlling material strength.
3. Process Accounting
OpenAIRE
Gilbertson, Keith
2002-01-01
Standard utilities can help you collect and interpret your Linux system's process accounting data. Describes the uses of process accounting, standard process accounting commands, and example code that makes use of process accounting utilities.
4. Evaluating Safeguards Benefits of Process Monitoring as compared with Nuclear Material Accountancy
Energy Technology Data Exchange (ETDEWEB)
Humberto Garcia; Wen-Chiao Lin; Reed Carlson
2014-07-01
This paper illustrates potential safeguards benefits that process monitoring (PM) may have as a diversion deterrent and as a complementary safeguards measure to nuclear material accountancy (NMA). This benefit is illustrated by quantifying the standard deviation associated with detecting a considered material diversion scenario using either an NMA-based method or a PM-based approach. To illustrate the benefits of PM for effective safeguards, we consider a reprocessing facility. We assume that the diversion of interest for detection manifests itself as a loss of Pu caused by abnormally operating a dissolver for an extended period to accomplish protracted diversion (or misdirection) of Pu to a retained (unconditioned) waste stream. For detecting the occurrence of this diversion (which involves anomalous operation of the dissolver), we consider two different data evaluation and integration (DEI) approaches, one based on NMA and the other based on PM. The approach based on PM does not directly do mass balance calculations, but rather monitors for the possible occurrence of anomaly patterns related to potential loss of nuclear material. It is thus assumed that the loss of a given mass amount of nuclear material can be directly associated with the execution of proliferation-driven activities that trigger the occurrence of an anomaly pattern consisting of series of events or signatures occurring at different unit operations and time instances. By effectively assessing these events over time and space, the PM-based DEI approach tries to infer whether this specific pattern of events has occurred and how many times within a given time period. To evaluate the goodness of PM, the 3 Sigma of the estimated mass loss is computed under both DEI approaches as function of the number of input batches processed. Simulation results are discussed.
5. Dynamical Systems Some Computational Problems
CERN Document Server
Guckenheimer, J; Guckenheimer, John; Worfolk, Patrick
1993-01-01
We present several topics involving the computation of dynamical systems. The emphasis is on work in progress and the presentation is informal -- there are many technical details which are not fully discussed. The topics are chosen to demonstrate the various interactions between numerical computation and mathematical theory in the area of dynamical systems. We present an algorithm for the computation of stable manifolds of equilibrium points, describe the computation of Hopf bifurcations for equilibria in parametrized families of vector fields, survey the results of studies of codimension two global bifurcations, discuss a numerical analysis of the Hodgkin and Huxley equations, and describe some of the effects of symmetry on local bifurcation.
6. Understanding Accountability from a Microanalysis of Power Dynamics in a Specialized STEM School
Science.gov (United States)
Teo, Tang Wee; Osborne, Margery
2014-01-01
7. Dynamic behavior of particulate/porous energetic materials
Science.gov (United States)
Nesterenko, Vitali F.; Chiu, Po-Hsun; Braithwaite, C. H.; Collins, Adam; Williamson, David Martin; Olney, Karl L.; Benson, David; McKenzie, Francesca
2012-03-01
Dynamic behavior of particulate/porous energetic materials in a broad range of dynamic conditions (low velocity impact and explosively driven expansion of rings) is discussed. Samples of these materials were fabricated using Cold Isostatic Pressing and Hot Isostatic Pressing with and without vacuum encapsulation. The current interest in these materials is due to the combination of their high strength and output of energy under critical conditions of mechanical deformation. They may exhibit high compressive and tensile strength with the ability to undergo bulk distributed fracture resulting in small size reactive fragments. The mechanical properties of these materials and the fragment sizes produced by fracturing are highly sensitive to mesostructure. For example, the dynamic strength of Al-W composites with fine W particles is significantly larger than the strength of composites with coarse W particles at the same porosity. The morphology of W inclusions had a strong effect on the dynamic strength and fracture pattern. Experimental results are compared with numerical data.
8. Dynamic brittle material response based on a continuum damage model
Energy Technology Data Exchange (ETDEWEB)
Chen, E.P.
1994-12-31
The response of brittle materials to dynamic loads was studied in this investigation based on a continuum damage model. Damage mechanism was selected to be interaction and growth of subscale cracks. Briefly, the cracks are activated by bulk tension and the density of activated cracks are described by a Weibull statistical distribution. The moduli of a cracked solid derived by Budiansky and OConnell are then used to represent the global material degradation due to subscale cracking. This continuum damage model was originally developed to study rock fragmentation and was modified in the present study to improve on the post-limit structural response. The model was implemented into a transient dynamic explicit finite element code PRONTO 2D and then used for a numerical study involving the sudden stretching of a plate with a centrally located hole. Numerical results characterizing the dynamic responses of the material were presented. The effect of damage on dynamic material behavior was discussed.
9. Ultrafast dynamic ellipsometry and spectroscopies of laser shocked materials
Energy Technology Data Exchange (ETDEWEB)
Mcgrane, Shawn David [Los Alamos National Laboratory; Bolme, Cindy B [Los Alamos National Laboratory; Whitley, Von H [Los Alamos National Laboratory; Moore, David S [Los Alamos National Laboratory
2010-01-01
Ultrafast ellipsometry and transient absorption spectroscopies are used to measure material dynamics under extreme conditions of temperature, pressure, and volumetric compression induced by shock wave loading with a chirped, spectrally clipped shock drive pulse.
10. 18 CFR 347.1 - Material to support request for newly established or changed property account depreciation studies.
Science.gov (United States)
2010-04-01
... request for newly established or changed property account depreciation studies. 347.1 Section 347.1... REGULATIONS UNDER THE INTERSTATE COMMERCE ACT OIL PIPELINE DEPRECIATION STUDIES § 347.1 Material to support request for newly established or changed property account depreciation studies. (a) Means of...
11. Dynamic High-Pressure Behavior of Hierarchical Heterogeneous Geological Materials
Science.gov (United States)
2016-04-01
pressure -density Hugoniot plots for simulations using the ‘mix 5’ option, as will be presented later. The volume weighted option for mixed cells (refered...AFRL-AFOSR-VA-TR-2016-0150 Dynamic High- Pressure Behavior of Geological Materials Naresh Thadhani GEORGIA TECH RESEARCH CORPORATION Final Report 04...31-12-2015 4. TITLE AND SUBTITLE Dynamic High- Pressure Behavior of Hierarchical Heterogeneous Geological Materials 5a. CONTRACT NUMBER 5b. GRANT
12. Human resource accounting in the system of value-based business management
Directory of Open Access Journals (Sweden)
Vitalii Pokynchereda
2017-08-01
Full Text Available Modern economic conditions are characterized by dynamism and complexity, in¬creased competitive confrontation at product markets, rapid changes of the market environment that leads to intensification of the search for advanced approaches to human resource management. Employees, their qualifications and experience are one of the most important factors, without which any prospects of economic growth are neutralized. The purpose of this paper is to substantiate the essence of human resources as a category of accounting, which is a prerequisite for formation of theoretical and methodological basis of their representation in the context of value-based business management implementation policy. The article substantiates the essence of human resources as the total number of employees at the company, who are carriers of human assets accumulated in themselves and inseparable from themselves, such as physical abilities, education, experience and professional knowledge that, in conjunction with using the elements of accounting method, creates the basis for presentation of human assets as the company’s right to use them as a part of intangible assets. Implementation of suggested approach to understand accounting nature of human resources, based on recognition of company’s right to use human assets carried by employees, creates a prerequisite for displaying information about them in the system of accounts and reports of the company that meets the needs of value-based management.
13. Regulation of the Bulgarian accounting system and its future perspectives
Directory of Open Access Journals (Sweden)
Snejana Basheva
2015-09-01
Full Text Available In 2013, the Fourth and Seventh Directives were replaced by a new Accounting Directive – Directive 2013/34/EC. The Directive is the outcome of EU aspirations to ease the business environment of small and medium-sized enterprises by simplifying the requirements with regard to reporting and mandatory disclosures for that category of enterprises. The entities of the practical sector (public and private limited liability companies, partnerships, general partnerships, etc. come within the scope of the Directive. The scope of the Directive excludes non-profit legal entities. The provisions of the Directive should, for the first time, be applied with regard to financial statements for reporting years beginning on or after January 1, 2016. Being an EC Member State, the Republic of Bulgaria has to transpose the Directive into the national accounting legislation by July 2015. The emphasis in this article is put on the basic problematic areas which occur in the process of the transposition of the Directive. As the possible solutions are based on established traditions and practices, the authors of this article try to identify the solutions to these problems taking into consideration the requirements imposed by the Directive itself. Four principal prob-lems are defined in the article: should there be a new Accounting Law and what should it include; should the Accounting Law include accounting principles; what groups and categories of enterprises should be differentiated and which accounting basis should be applied by any of them.
14. Theoretical Studies of Small-System Thermodynamics in Energetic Materials
Science.gov (United States)
2016-01-06
3D hard - sphere and Lennard-Jones fluids for which the surroundings are modelled as reflecting hard walls that confine the system along one direction...Molecular Materials under Static and Dynamic Compression " 2013 Fall ACS COMP Symposium: "Chemical Mechanisms in Advanced Materials" in the Materials...Jiang: 19th Biennial Conference of the APS Topical Group on Shock Compression of Condensed Matter (SCCM-2015) Tampa, Florida, 2015; “Molecular
15. 21 CFR 21.71 - Disclosure of records in Privacy Act Record Systems; accounting required.
Science.gov (United States)
2010-04-01
... Systems; accounting required. 21.71 Section 21.71 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT... Record Systems; accounting required. (a) Except as provided in § 21.70, a record about an individual that... of the disclosure. The accounting shall not be considered a Privacy Act Record System. (2) Retain...
16. 49 CFR Appendix I to Part 1201 - Certification of Branch Line Accounting System Records
Science.gov (United States)
2010-10-01
... 49 Transportation 9 2010-10-01 2010-10-01 false Certification of Branch Line Accounting System... RAILROAD COMPANIES Pt. 1201, App. I Appendix I to Part 1201—Certification of Branch Line Accounting System...__ the branch line accounting system data were collected and maintained for each line that met the...
17. Ultrafast impact dynamics of reactive materials (Dlott)
Science.gov (United States)
2013-04-16
Submitted Patents Awarded Awards Jupiter Laser Facility Program Advisory Committee, Lawrence Livermore National Laboratory, 2008, 2011 Executive...related materials such as B/Teflon) to ultrafast laser flash heating. 36-39 In fact during the project period we wrapped up the flash-heating
18. A Review of the Factors Associated with the Adoption of Accounting Information Systems in Gulf Countries.
Science.gov (United States)
Hammour, Hadal; Househ, Mowafa; Razzak, Hira Abdul
2017-01-01
This review attempts to elucidate the significance of accounting information systems within healthcare settings in the Gulf regions. Information and communication technologies (ICT) has provided accounting system the ability to help an organization use and develop computerized systems to record and track financial transactions. Accounting information systems, if well implemented, can permit healthcare sectors in the Gulf regions to produce reports that can support the decision making process. Additional abilities of an accounting information systems include faster processing, enriched accuracy, amplified functionality, and improved external reporting. Training of hospital staff can help in enhancing the use of accounting information systems in gulf hospitals.
19. Material Control and Accounting Design Considerations for High-Temperature Gas Reactors
Energy Technology Data Exchange (ETDEWEB)
Trond Bjornard; John Hockert
2011-08-01
The subject of this report is domestic safeguards and security by design (2SBD) for high-temperature gas reactors, focusing on material control and accountability (MC&A). The motivation for the report is to provide 2SBD support to the Next Generation Nuclear Plant (NGNP) project, which was launched by Congress in 2005. This introductory section will provide some background on the NGNP project and an overview of the 2SBD concept. The remaining chapters focus specifically on design aspects of the candidate high-temperature gas reactors (HTGRs) relevant to MC&A, Nuclear Regulatory Commission (NRC) requirements, and proposed MC&A approaches for the two major HTGR reactor types: pebble bed and prismatic. Of the prismatic type, two candidates are under consideration: (1) GA's GT-MHR (Gas Turbine-Modular Helium Reactor), and (2) the Modular High-Temperature Reactor (M-HTR), a derivative of Areva's Antares reactor. The future of the pebble-bed modular reactor (PBMR) for NGNP is uncertain, as the PBMR consortium partners (Westinghouse, PBMR [Pty] and The Shaw Group) were unable to agree on the path forward for NGNP during 2010. However, during the technology assessment of the conceptual design phase (Phase 1) of the NGNP project, AREVA provided design information and technology assessment of their pebble bed fueled plant design called the HTR-Module concept. AREVA does not intend to pursue this design for NGNP, preferring instead a modular reactor based on the prismatic Antares concept. Since MC&A relevant design information is available for both pebble concepts, the pebble-bed HTGRs considered in this report are: (1) Westinghouse PBMR; and (2) AREVA HTR-Module. The DOE Office of Nuclear Energy (DOE-NE) sponsors the Fuel Cycle Research and Development program (FCR&D), which contains an element specifically focused on the domestic (or state) aspects of SBD. This Material Protection, Control and Accountancy Technology (MPACT) program supports the present work
20. 75 FR 13329 - Implications of Financial Accounting System (FAS) 166 on SBA Guaranteed Loan Programs
Science.gov (United States)
2010-03-19
... ADMINISTRATION Implications of Financial Accounting System (FAS) 166 on SBA Guaranteed Loan Programs AGENCY... Administration (SBA) is soliciting information and views from the public on: (1) The effect that the accounting changes mandated by the Financial Accounting Standards Board (FASB) in Financial Accounting Standard (FAS...
1. 14 CFR Sec. 1-3 - General description of system of accounts and reports.
Science.gov (United States)
2010-01-01
... CERTIFICATED AIR CARRIERS General Accounting Provisions Sec. 1-3 General description of system of accounts and... reflect the varying needs and capacities of different air carriers without impairing basic accounting... and loss elements which are recorded during the current accounting year are subclassified as...
2. Dynamical stability of Hamiltonian systems
Institute of Scientific and Technical Information of China (English)
2000-01-01
Dynamical stability has become the center of study on Hamiltonian system. In this article we intro-duce the recent development in some areas closely related to this topic, such as the KAM theory, Mather theory, Arnolddiffusion and non-singular collision of n-body problem.
3. Advanced dynamics of mechanical systems
CERN Document Server
Cheli, Federico
2015-01-01
This book introduces a general approach for schematization of mechanical systems with rigid and deformable bodies. It proposes a systems approach to reproduce the interaction of the mechanical system with different force fields such as those due to the action of fluids or contact forces between bodies, i.e., with forces dependent on the system states, introducing the concepts of the stability of motion. In the first part of the text mechanical systems with one or more degrees of freedom with large motion and subsequently perturbed in the neighborhood of the steady state position are analyzed. Both discrete and continuous systems (modal approach, finite elements) are analyzed. The second part is devoted to the study of mechanical systems subject to force fields, the rotor dynamics, techniques of experimental identification of the parameters, and random excitations. The book will be especially valuable for students of engineering courses in Mechanical Systems, Aerospace, Automation, and Energy but will also b...
4. Controlling dynamics in diatomic systems
Praveen Kumar; Harjinder Singh
2007-09-01
Controlling molecular energetics using laser pulses is exemplified for nuclear motion in two different diatomic systems. The problem of finding the optimized field for maximizing a desired quantum dynamical target is formulated using an iterative method. The method is applied for two diatomic systems, HF and OH. The power spectra of the fields and evolution of populations of different vibrational states during transitions are obtained.
5. Algebraic Structure of Dynamical Systems
Science.gov (United States)
2017-05-22
Scholar project report; no. 461 (2017) ALGEBRAIC STRUCTURE OF DYNAMICAL SYSTEMS by MIDN 1/C James P. Talisse United States Naval Academy Annapolis, MD...based on the structure of algebraic objects associated with it. In this project we study two algebraic objects, centralizers and topological full groups...group completely defines the system up to time reversal. We apply numerical estimates to draw conclusions about the algebraic properties of this group
6. Adaptive, dynamic, and resilient systems
CERN Document Server
Suri, Niranjan
2015-01-01
As the complexity of today's networked computer systems grows, they become increasingly difficult to understand, predict, and control. Addressing these challenges requires new approaches to building these systems. Adaptive, Dynamic, and Resilient Systems supplies readers with various perspectives of the critical infrastructure that systems of networked computers rely on. It introduces the key issues, describes their interrelationships, and presents new research in support of these areas.The book presents the insights of a different group of international experts in each chapter. Reporting on r
7. Lattice dynamical studies of HTSC materials
Energy Technology Data Exchange (ETDEWEB)
Pintschovius, L.; Pyka, N.; Reichardt, W. (Kernforschungszentrum Karlsruhe, INFP (Germany)); Rumiantsev, A.Yu.; Mitrofanov, N.L.; Ivanov, A.S. (I.V. Kurchatov-Inst. of Atomic Energy, Moscow (USSR)); Collin, G.; Bourges, P. (Lab. Leon Brillouin, CEA-CNRS, CEN Saclay, 91 - Gif-sur-Yvette (France))
1991-12-01
A survey is presented on recent progress in the understanding of the lattice dynamics in Nd{sub 2}CuO{sub 4}, (La,Sr){sub 2}CuO{sub 4} and YBa{sub 2}Cu{sub 3}O{sub 6/7}. Classical anharmonicity and twinning were found to be major complications for the interpretation of the data. The lattice vibrations of the cuprates can now largely be described within the framework of shell models for strongly ionic compounds. Phonon anomalies inferred from a comparison of doped and undoped compounds resemble those found in classical superconductors. (orig.).
8. THE GENERAL ARCHITECTURE OF THE ACCOUNTING INFORMATION SYSTEM AT TRADE ENTITIES
Directory of Open Access Journals (Sweden)
2016-08-01
Full Text Available At trade entities, most of the activities carried out within the framework of accounting information system revolve around accounting operations, they being the basis of this system and the financial perspective over an entity activity, through the accounts, by the way, most of the accounting information resulted from accounting information system are obtained by analyzing the information in the accounts. In the context of the existence of an integrated information system almost all accounting operations can be generated automatically or semi-automatically, by retrieving data from other modules of the informatic system existent within the entity: purchasing, sales, human resources, asset ,cash register, bank, etc. Otherwise, to dispose in a trade entity of a performant financial-accounting information system it should be analyzed, designed and implemented only in conjunction with other components they interact with, namely: purchasing, sales, human resources, assets, cash register, bank, etc., in order to avoid certain inherent redundancy in other approaches.
9. Compaction dynamics of crunchy granular material
Directory of Open Access Journals (Sweden)
Guillard François
2017-01-01
Full Text Available Compaction of brittle porous material leads to a wide variety of densification patterns. Static compaction bands occurs naturally in rocks or bones, and have important consequences in industry for the manufacturing of powder tablets or metallic foams for example. Recently, oscillatory compaction bands have been observed in brittle porous media like snow or cereals. We will discuss the great variety of densification patterns arising during the compaction of puffed rice, including erratic compaction at low velocity, one or several travelling compaction bands at medium velocity and homogeneous compaction at larger velocity. The conditions of existence of each pattern are studied thanks to a numerical spring lattice model undergoing breakage and is mapped to the phase diagram of the patterns based on dimensionless characteristic quantities. This also allows to rationalise the evolution of the compaction behaviour during a single test. Finally, the localisation of compaction bands is linked to the strain rate sensitivity of the material.
10. Dynamic combinatorial self-replicating systems.
Science.gov (United States)
Moulin, Emilie; Giuseppone, Nicolas
2012-01-01
Thanks to their intrinsic network topologies, dynamic combinatorial libraries (DCLs) represent new tools for investigating fundamental aspects related to self-organization and adaptation processes. Very recently the first examples integrating self-replication features within DCLs have pushed even further the idea of implementing dynamic combinatorial chemistry (DCC) towards minimal systems capable of self-construction and/or evolution. Indeed, feedback loop processes - in particular in the form of autocatalytic reactions - are keystones to build dynamic supersystems which could possibly approach the roots of "Darwinian" evolvability at mesoscale. This topic of current interest also shows significant potentialities beyond its fundamental character, because truly smart and autonomous materials for the future will have to respond to changes of their environment by selecting and by exponentially amplifying their fittest constituents.
11. A continuum theory for modeling the dynamics of crystalline materials.
Science.gov (United States)
Xiong, Liming; Chen, Youping; Lee, James D
2009-02-01
This paper introduces a multiscale field theory for modeling and simulation of the dynamics of crystalline materials. The atomistic formulation of a multiscale field theory is briefly introduced. Its applicability is discussed. A few application examples, including phonon dispersion relations of ferroelectric materials BiScO3 and MgO nano dot under compression are presented.
12. The dynamical crossover in attractive colloidal systems
Energy Technology Data Exchange (ETDEWEB)
Mallamace, Francesco [Dipartimento di Fisica e Scienze della Terra, Università di Messina and CNISM, I-98168 Messina (Italy); Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Corsaro, Carmelo [Dipartimento di Fisica e Scienze della Terra, Università di Messina and CNISM, I-98168 Messina (Italy); Stanley, H. Eugene [Center for Polymer Studies and Department of Physics, Boston University, Boston, Massachusetts 02215 (United States); Mallamace, Domenico [Dipartimento di Scienze dell’Ambiente, della Sicurezza, del Territorio, degli Alimenti e della Salute, Università di Messina, I-98166 Messina (Italy); Chen, Sow-Hsin [Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)
2013-12-07
We study the dynamical arrest in an adhesive hard-sphere colloidal system. We examine a micellar suspension of the Pluronic-L64 surfactant in the temperature (T) and volume fraction (ϕ) phase diagram. According to mode-coupling theory (MCT), this system is characterized by a cusp-like singularity and two glassy phases: an attractive glass (AG) phase and a repulsive glass (RG) phase. The T − ϕ phase diagram of this system as confirmed by a previous series of scattering data also exhibits a Percolation Threshold (PT) line, a reentrant behavior (AG-liquid-RG), and a glass-to-glass transition. The AG phase can be generated out of the liquid phase by using T and ϕ as control parameters. We utilize viscosity and nuclear magnetic resonance (NMR) techniques. NMR data confirm all the characteristic properties of the colloidal system phase diagram and give evidence of the onset of a fractal-like percolating structure at a precise threshold. The MCT scaling laws used to study the shear viscosity as a function of ϕ and T show in both cases a fragile-to-strong liquid glass-forming dynamic crossover (FSC) located near the percolation threshold where the clustering process is fully developed. These results suggest a larger thermodynamic generality for this phenomenon, which is usually studied only as a function of the temperature. We also find that the critical values of the control parameters, coincident with the PT line, define the locus of the FSC. In the region between the FSC and the glass transition lines the system dynamics are dominated by clustering effects. We thus demonstrate that it is possible, using the conceptual framework provided by extended mode-coupling theory, to describe the way a system approaches dynamic arrest, taking into account both cage and hopping effects.
13. Common accounting system for monitoring the ATLAS Distributed Computing resources
CERN Document Server
Karavakis, E; The ATLAS collaboration; Campana, S; Gayazov, S; Jezequel, S; Saiz, P; Sargsyan, L; Schovancova, J; Ueda, I
2014-01-01
This paper covers in detail a variety of accounting tools used to monitor the utilisation of the available computational and storage resources within the ATLAS Distributed Computing during the first three years of Large Hadron Collider data taking. The Experiment Dashboard provides a set of common accounting tools that combine monitoring information originating from many different information sources; either generic or ATLAS specific. This set of tools provides quality and scalable solutions that are flexible enough to support the constantly evolving requirements of the ATLAS user community.
14. HARMONISATION OF CROATIAN ACCOUNTING SYSTEM WITH EUROPEAN UNION'S REQUESTS
Directory of Open Access Journals (Sweden)
Ivana Mamic Sacer
2007-06-01
Full Text Available A process of accounting harmonization is a result of a process of globalization. One of the fields that are certainly important for harmonisation, not only in Croatian case, but also for European and world economy consideration is the field of financial reporting. Because of differences in characteristics of national regulations, there are some differences in financial reporting framework for companies that are oriented only on national (domestic market and for those that have global business policy. In this paper, authors compare Croatian Law on accounting with European Union requests and some world experiences in financial reporting.
15. Dynamics of immune system vulnerabilities
Science.gov (United States)
Stromberg, Sean P.
The adaptive immune system can be viewed as a complex system, which adapts, over time, to reflect the history of infections experienced by the organism. Understanding its operation requires viewing it in terms of tradeoffs under constraints and evolutionary history. It typically displays "robust, yet fragile" behavior, meaning common tasks are robust to small changes but novel threats or changes in environment can have dire consequences. In this dissertation we use mechanistic models to study several biological processes: the immune response, the homeostasis of cells in the lymphatic system, and the process that normally prevents autoreactive cells from entering the lymphatic system. Using these models we then study the effects of these processes interacting. We show that the mechanisms that regulate the numbers of cells in the immune system, in conjunction with the immune response, can act to suppress autoreactive cells from proliferating, thus showing quantitatively how pathogenic infections can suppress autoimmune disease. We also show that over long periods of time this same effect can thin the repertoire of cells that defend against novel threats, leading to an age correlated vulnerability. This vulnerability is shown to be a consequence of system dynamics, not due to degradation of immune system components with age. Finally, modeling a specific tolerance mechanism that normally prevents autoimmune disease, in conjunction with models of the immune response and homeostasis we look at the consequences of the immune system mistakenly incorporating pathogenic molecules into its tolerizing mechanisms. The signature of this dynamic matches closely that of the dengue virus system.
16. Materials Knowledge Systems in Python - A Data Science Framework for Accelerated Development of Hierarchical Materials.
Science.gov (United States)
Brough, David B; Wheeler, Daniel; Kalidindi, Surya R
2017-03-01
There is a critical need for customized analytics that take into account the stochastic nature of the internal structure of materials at multiple length scales in order to extract relevant and transferable knowledge. Data driven Process-Structure-Property (PSP) linkages provide systemic, modular and hierarchical framework for community driven curation of materials knowledge, and its transference to design and manufacturing experts. The Materials Knowledge Systems in Python project (PyMKS) is the first open source materials data science framework that can be used to create high value PSP linkages for hierarchical materials that can be leveraged by experts in materials science and engineering, manufacturing, machine learning and data science communities. This paper describes the main functions available from this repository, along with illustrations of how these can be accessed, utilized, and potentially further refined by the broader community of researchers.
17. Dynamical systems probabilistic risk assessment.
Energy Technology Data Exchange (ETDEWEB)
Denman, Matthew R.; Ames, Arlo Leroy
2014-03-01
Probabilistic Risk Assessment (PRA) is the primary tool used to risk-inform nuclear power regulatory and licensing activities. Risk-informed regulations are intended to reduce inherent conservatism in regulatory metrics (e.g., allowable operating conditions and technical specifications) which are built into the regulatory framework by quantifying both the total risk profile as well as the change in the risk profile caused by an event or action (e.g., in-service inspection procedures or power uprates). Dynamical Systems (DS) analysis has been used to understand unintended time-dependent feedbacks in both industrial and organizational settings. In dynamical systems analysis, feedback loops can be characterized and studied as a function of time to describe the changes to the reliability of plant Structures, Systems and Components (SSCs). While DS has been used in many subject areas, some even within the PRA community, it has not been applied toward creating long-time horizon, dynamic PRAs (with time scales ranging between days and decades depending upon the analysis). Understanding slowly developing dynamic effects, such as wear-out, on SSC reliabilities may be instrumental in ensuring a safely and reliably operating nuclear fleet. Improving the estimation of a plant's continuously changing risk profile will allow for more meaningful risk insights, greater stakeholder confidence in risk insights, and increased operational flexibility.
18. Dynamical systems probabilistic risk assessment
Energy Technology Data Exchange (ETDEWEB)
Denman, Matthew R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ames, Arlo Leroy [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2014-03-01
Probabilistic Risk Assessment (PRA) is the primary tool used to risk-inform nuclear power regulatory and licensing activities. Risk-informed regulations are intended to reduce inherent conservatism in regulatory metrics (e.g., allowable operating conditions and technical specifications) which are built into the regulatory framework by quantifying both the total risk profile as well as the change in the risk profile caused by an event or action (e.g., in-service inspection procedures or power uprates). Dynamical Systems (DS) analysis has been used to understand unintended time-dependent feedbacks in both industrial and organizational settings. In dynamical systems analysis, feedback loops can be characterized and studied as a function of time to describe the changes to the reliability of plant Structures, Systems and Components (SSCs). While DS has been used in many subject areas, some even within the PRA community, it has not been applied toward creating long-time horizon, dynamic PRAs (with time scales ranging between days and decades depending upon the analysis). Understanding slowly developing dynamic effects, such as wear-out, on SSC reliabilities may be instrumental in ensuring a safely and reliably operating nuclear fleet. Improving the estimation of a plant's continuously changing risk profile will allow for more meaningful risk insights, greater stakeholder confidence in risk insights, and increased operational flexibility.
19. Opportunities and challenges for implementing cost accounting systems in the Kenyan health system
Directory of Open Access Journals (Sweden)
Elesban Kihuba
2016-06-01
Full Text Available Background: Low- and middle-income countries need to sustain efficiency and equity in health financing on their way to universal health care coverage. However, systems meant to generate quality economic information are often deficient in such settings. We assessed the feasibility of streamlining cost accounting systems within the Kenyan health sector to illustrate the pragmatic challenges and opportunities. Design: We reviewed policy documents, and conducted field observations and semi-structured interviews with key informants in the health sector. We used an adapted Human, Organization and Technology fit (HOT-fit framework to analyze the components and standards of a cost accounting system. Results: Among the opportunities for a viable cost accounting system, we identified a supportive broad policy environment, political will, presence of a national data reporting architecture, good implementation experience with electronic medical records systems, and the availability of patient clinical and resource use data. However, several practical issues need to be considered in the design of the system, including the lack of a framework to guide the costing process, the lack of long-term investment, the lack of appropriate incentives for ground-level staff, and a risk of overburdening the current health management information system. Conclusion: To facilitate the implementation of cost accounting into the health sector, the design of any proposed system needs to remain simple and attuned to the local context.
20. Opportunities and challenges for implementing cost accounting systems in the Kenyan health system.
Science.gov (United States)
Kihuba, Elesban; Gheorghe, Adrian; Bozzani, Fiammetta; English, Mike; Griffiths, Ulla K
2016-01-01
Low- and middle-income countries need to sustain efficiency and equity in health financing on their way to universal health care coverage. However, systems meant to generate quality economic information are often deficient in such settings. We assessed the feasibility of streamlining cost accounting systems within the Kenyan health sector to illustrate the pragmatic challenges and opportunities. We reviewed policy documents, and conducted field observations and semi-structured interviews with key informants in the health sector. We used an adapted Human, Organization and Technology fit (HOT-fit) framework to analyze the components and standards of a cost accounting system. Among the opportunities for a viable cost accounting system, we identified a supportive broad policy environment, political will, presence of a national data reporting architecture, good implementation experience with electronic medical records systems, and the availability of patient clinical and resource use data. However, several practical issues need to be considered in the design of the system, including the lack of a framework to guide the costing process, the lack of long-term investment, the lack of appropriate incentives for ground-level staff, and a risk of overburdening the current health management information system. To facilitate the implementation of cost accounting into the health sector, the design of any proposed system needs to remain simple and attuned to the local context.
1. Opportunities and challenges for implementing cost accounting systems in the Kenyan health system
Science.gov (United States)
Kihuba, Elesban; Gheorghe, Adrian; Bozzani, Fiammetta; English, Mike; Griffiths, Ulla K.
2016-01-01
Background Low- and middle-income countries need to sustain efficiency and equity in health financing on their way to universal health care coverage. However, systems meant to generate quality economic information are often deficient in such settings. We assessed the feasibility of streamlining cost accounting systems within the Kenyan health sector to illustrate the pragmatic challenges and opportunities. Design We reviewed policy documents, and conducted field observations and semi-structured interviews with key informants in the health sector. We used an adapted Human, Organization and Technology fit (HOT-fit) framework to analyze the components and standards of a cost accounting system. Results Among the opportunities for a viable cost accounting system, we identified a supportive broad policy environment, political will, presence of a national data reporting architecture, good implementation experience with electronic medical records systems, and the availability of patient clinical and resource use data. However, several practical issues need to be considered in the design of the system, including the lack of a framework to guide the costing process, the lack of long-term investment, the lack of appropriate incentives for ground-level staff, and a risk of overburdening the current health management information system. Conclusion To facilitate the implementation of cost accounting into the health sector, the design of any proposed system needs to remain simple and attuned to the local context. PMID:27357072
2. Vertebrate gravity sensors as dynamic systems
Science.gov (United States)
Ross, M. D.
1985-01-01
This paper considers verterbrate gravity receptors as dynamic sensors. That is, it is hypothesized that gravity is a constant force to which an acceleration-sensing system would readily adapt. Premises are considered in light of the presence of kinocilia on hair cells of vertebrate gravity sensors; differences in loading of the sensors among species; and of possible reduction in loading by inclusion of much organic material in otoconia. Moreover, organic-inorganic interfaces may confer a piezoelectric property upon otoconia, which increase the sensitivity of the sensory system to small accelerations. Comparisons with man-made accelerometers are briefly taken up.
3. Chaotic Behavior in a Switched Dynamical System
Directory of Open Access Journals (Sweden)
Fatima El Guezar
2008-01-01
Full Text Available We present a numerical study of an example of piecewise linear systems that constitute a class of hybrid systems. Precisely, we study the chaotic dynamics of the voltage-mode controlled buck converter circuit in an open loop. By considering the voltage input as a bifurcation parameter, we observe that the obtained simulations show that the buck converter is prone to have subharmonic behavior and chaos. We also present the corresponding bifurcation diagram. Our modeling techniques are based on the new French native modeler and simulator for hybrid systems called Scicos (Scilab connected object simulator which is a Scilab (scientific laboratory package. The followed approach takes into account the hybrid nature of the circuit.
4. Frequency-dependent dynamic effective properties of porous materials
Institute of Scientific and Technical Information of China (English)
Peijun Wei; Zhuping Huang
2005-01-01
The frequency-dependent dynamic effective properties (phase velocity, attenuation and elastic modulus) of porous materials are studied numerically. The coherent plane longitudinal and shear wave equations, which are obtained by averaging on the multiple scattering fields, are used to evaluate the frequency-dependent dynamic effective properties of a porous material. It is found that the prediction of the dynamic effective properties includes the size effects of voids which are not included in most prediction of the traditional static effective properties. The prediction of the dynamic effective elastic modulus at a relatively low frequency range is compared with that of the traditional static effective elastic modulus, and the dynamic effective elastic modulus is found to be very close to the Hashin-Shtrikman upper bound.
5. A mechanical brake hardware-in-the-loop simulation of a railway vehicle that accounts for hysteresis and pneumatic cylinder dynamics
OpenAIRE
Dong-Chan Lee; Chul-Goo Kang
2015-01-01
A brake hardware-in-the-loop simulation system for a railway vehicle provides an effective platform for testing the braking performance under various dangerous braking conditions. However, in general, four-brake calipers are required to implement a mechanical brake system for one car. In this article, we implement a brake hardware-in-the-loop simulation system only with one brake caliper and three air tanks accounting for hysteresis and pneumatic cylinder dynamics, ultimately saving installat...
6. Programmable temperature control system for biological materials
Science.gov (United States)
Anselmo, V. J.; Harrison, R. G.; Rinfret, A. P.
1982-01-01
A system was constructed which allows programmable temperature-time control for a 5 cu cm sample volume of arbitrary biological material. The system also measures the parameters necessary for the determination of the sample volume specific heat and thermal conductivity as a function of temperature, and provides a detailed measurement of the temperature during phase change and a means of calculating the heat of the phase change. Steady-state and dynamic temperature control is obtained by supplying heat to the sample volume through resistive elements constructed as an integral part of the sample container. For cooling purposes, this container is totally immersed into a cold heat sink. Using a mixture of dry ice and alcohol at 79 C, the sample volume can be controlled from +40 to -60 C at rates from steady state to + or - 65 C/min. Steady-state temperature precision is better than 0.2 C, while the dynamic capability depends on the temperature rate of change as well as the mass of both the sample and the container.
7. Thermoviscoelastic dynamic response for a composite material thin narrow strip
Energy Technology Data Exchange (ETDEWEB)
Dai, Hong Liang; Qi, Li-Li; Liu, Hai-Bo [Hunan University, Changsha (China)
2015-02-15
Based on von Karman nonlinear strain-displacement relationships and classical thin plate theory, a list of nonlinear dynamic equilibrium equations for a viscoelastic composite material thin narrow strip under thermal and mechanic loads are deduced. According to the material constitutive relationship and the relaxation modulus in the form of the Prony series, combing with the Newmark method and the Newton-cotes integration method, a new numerical algorithm for direct solving the whole problem in the time domain is established. By applying this numerical algorithm, the viscoelastic composite material thin narrow strip as the research subject is analyzed systematically, and its rich dynamical behaviors are revealed comprehensively. To verify the accuracy of the present work, a comparison is made with previously published results. Finally, the viscoelastic composite material thin narrow strip under harmonic excitation load and impact load are discussed in detail, and many valuable thermoviscoelastic dynamic characteristics are revealed.
8. Materials Selection for Aerospace Systems
Science.gov (United States)
Arnold, Steven M.; Cebon, David; Ashby, Mike
2012-01-01
A systematic design-oriented, five-step approach to material selection is described: 1) establishing design requirements, 2) material screening, 3) ranking, 4) researching specific candidates and 5) applying specific cultural constraints to the selection process. At the core of this approach is the definition performance indices (i.e., particular combinations of material properties that embody the performance of a given component) in conjunction with material property charts. These material selection charts, which plot one property against another, are introduced and shown to provide a powerful graphical environment wherein one can apply and analyze quantitative selection criteria, such as those captured in performance indices, and make trade-offs between conflicting objectives. Finding a material with a high value of these indices maximizes the performance of the component. Two specific examples pertaining to aerospace (engine blades and pressure vessels) are examined, both at room temperature and elevated temperature (where time-dependent effects are important) to demonstrate the methodology. The discussion then turns to engineered/hybrid materials and how these can be effectively tailored to fill in holes in the material property space, so as to enable innovation and increases in performance as compared to monolithic materials. Finally, a brief discussion is presented on managing the data needed for materials selection, including collection, analysis, deployment, and maintenance issues.
9. Thermal Systems and Materials Testing
Science.gov (United States)
Aguirre, Nathan
2010-01-01
During my internship, I was involved in Boeing Thermal System/M&P, which handles maintenance and repairs of shuttle tiles, blankets, gap fillers, etc. One project I took part in was the revision of TPS-227, a repair process to tiles that entailed drilling out tile damage and using a cylindrical insert to fill the hole. The previous specification used minimal adhesive for application and when the adhesive cured, there would be several voids in the adhered material, causing an unsatisfactory bond. The testing compared several new methods and I analyzed the number of voids produced by each method to determine which one was most effective at eliminating void space. We revised the original process to apply a light adhesive coat to the top 25% of the borehole and a heavy coat to 100% of the insert. I was also responsible for maintaining the subnominal bond database, which records all unsatisfactory SIP (Strain Isolator Pad) bonds. I then archived each SIP physically for future referral data and statistics. In addition, I performed post-flight tile inspections for damages and wrote dispositions to have these tiles repaired. This also included writing a post-flight damage report for a section of Atlantis and creating summarized repair process guidelines for orbiter technicians.
10. Multi-scale modeling of deformation and fracture of ceramic materials under dynamic loading
Science.gov (United States)
2013-06-01
The multi-scale approach to dynamic analysis of deformation and fracture, taking place in structured condensed matter show a great promise in prediction of the mechanical response for new materials. In present work the results of two-level simulations on deformation and fracture mechanisms for brittle materials subjected to impulse and shock-wave loadings are demonstrated. The dynamic effects occurring in structured representative volumes of the ceramics and the processes relating to damage and fracture of the ceramic materials with porous structures, ceramic composites and nanocomposites were modeled using the SPH methods. The grain, phase and porous structures were simulated in an explicit form. The presence of dispersed inclusions, dislocation substructures, nano - and micro-voids at the lower structural level were taking into account in an implicit form. The two-level model allows taking into account different relaxation and fracturing characteristic times at the different structural levels. This approach suggest to describe the relaxation process at the higher structural level in terms of integrated effect of the lower level processes. It is found that clusters of nano-voids in ceramic materials are the centers of damage nucleation. The presence of the clusters of nano-voids in ceramic materials subjected to dynamic loadings results in decrease of the Hugoniot elastic limit value.
11. Characterization of dynamic thermal control schemes and heat transfer pathways for incorporating variable emissivity electrochromic materials into a space suit heat rejection system
Science.gov (United States)
Massina, Christopher James
The feasibility of conducting long duration human spaceflight missions is largely dependent on the provision of consumables such as oxygen, water, and food. In addition to meeting crew metabolic needs, water sublimation has long served as the primary heat rejection mechanism in space suits during extravehicular activity (EVA). During a single eight hour EVA, approximately 3.6 kg (8 lbm) of water is lost from the current suit. Reducing the amount of expended water during EVA is a long standing goal of space suit life support systems designers; but to date, no alternate thermal control mechanism has demonstrated the ability to completely eliminate the loss. One proposed concept is to convert the majority of a space suit's surface area into a radiator such that the local environment can be used as a radiative thermal sink for rejecting heat without mass loss. Due to natural variations in both internal (metabolic) loads and external (environmental) sink temperatures, radiative transport must be actively modulated in order to maintain an acceptable thermal balance. Here, variable emissivity electrochromic devices are examined as the primary mechanism for enabling variable heat rejection. This dissertation focuses on theoretical and empirical evaluations performed to determine the feasibility of using a full suit, variable emissivity radiator architecture for space suit thermal control. Operational envelopes are described that show where a given environment and/or metabolic load combination may or may not be supported by the evaluated thermal architecture. Key integration considerations and guidelines include determining allowable thermal environments, defining skin-to-radiator heat transfer properties, and evaluating required electrochromic performance properties. Analysis also considered the impacts of dynamic environmental changes and the architecture's extensibility to EVA on the Martian surface. At the conclusion of this work, the full suit, variable emissivity
12. 14 CFR Section 1 - Introduction to System of Accounts and Reports
Science.gov (United States)
2010-01-01
... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Introduction to System of Accounts and Reports Section 1 Section 1 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION... AIR CARRIERS General Accounting Provisions Section 1 Introduction to System of Accounts and Reports ...
13. 49 CFR 1242.19 - Electric power systems (account XX-19-21).
Science.gov (United States)
2010-10-01
... 49 Transportation 9 2010-10-01 2010-10-01 false Electric power systems (account XX-19-21). 1242.19... Structures § 1242.19 Electric power systems (account XX-19-21). Separate common expenses on basis of common expenses of electric power purchased or produced for motive power (accounts XX-51-68 and XX-52-68)....
14. 18 CFR 367.1540 - Account 154, Materials and operating supplies.
Science.gov (United States)
2010-04-01
... NATURAL GAS ACT Balance Sheet Chart of Accounts Current and Accrued Assets § 367.1540 Account 154... ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY REGULATIONS UNDER THE PUBLIC UTILITY HOLDING...
15. Formal languages in dynamical systems
CERN Document Server
Troll, G
1993-01-01
We treat here the interrelation between formal languages and those dynamical systems that can be described by cellular automata (CA). There is a well-known injective map which identifies any CA-invariant subshift with a central formal language. However, in the special case of a symbolic dynamics, i.e. where the CA is just the shift map, one gets a stronger result: the identification map can be extended to a functor between the categories of symbolic dynamics and formal languages. This functor additionally maps topological conjugacies between subshifts to empty-string-limited generalized sequential machines between languages. If the periodic points form a dense set, a case which arises in a commonly used notion of chaotic dynamics, then an even more natural map to assign a formal language to a subshift is offered. This map extends to a functor, too. The Chomsky hierarchy measuring the complexity of formal languages can be transferred via either of these functors from formal languages to symbolic dynamics and p...
16. Synchronization of nonautonomous dynamical systems
Directory of Open Access Journals (Sweden)
Peter E. Kloeden
2003-04-01
Full Text Available The synchronization of two nonautonomous dynamical systems is considered, where the systems are described in terms of a skew-product formalism, i. e., in which an inputed autonomous driving system governs the evolution of the vector field of a differential equation with the passage of time. It is shown that the coupled trajectories converge to each other as time increases for sufficiently large coupling coefficient and also that the component sets of the pullback attractor of the coupled system converges upper semi continuously as the coupling parameter increases to the diagonal of the product of the corresponding component sets of the pullback attractor of a system generated by the average of the vector fields of the original uncoupled systems.
17. Structural Materials for Innovative Nuclear Systems
Energy Technology Data Exchange (ETDEWEB)
Yvon, Pascal [Commissariat a l' energie atomique - CEA (France)
2011-07-01
This series of slides deal with: the goals for advanced fission reactor systems; the requirements for structural materials; a focus on two important types of materials: ODS and CMC; a focus on materials under irradiation (multiscale modelling, experimental simulation, 'smart' experiments in materials testing reactors); some concluding remarks.
18. Reference material systems: a sourcebook for material assessment
Energy Technology Data Exchange (ETDEWEB)
Bhagat, N. (ed.)
1976-12-01
A reference set of data related to material systems and a framework for carrying out the material technologies assessment are presented. While the bulk of renewables have been considered in this report, the nonrenewable materials dealt with here include structural materials only, such as steel, aluminum, cement and concrete, and bricks. The complete data set is supposed to include material flows, energy requirements, capital and labor inputs, and environmental effects for each process that a resource must go through to become a useful material for an end use. Although effort has been made to obtain as much information as possible, considerable gaps in data, apparent throughout this report, could not be avoided. A new material technology can be evaluated by substituting that technology for appropriate elements of the reference materials system and calculating the net change in material resource, energy, capital and labor requirements, and environmental impacts. This combination of information thus serves as a means of evaluating the potential benefits to be gained by research in various material technologies.
19. Hidden attractors in dynamical systems
Science.gov (United States)
2016-06-01
Complex dynamical systems, ranging from the climate, ecosystems to financial markets and engineering applications typically have many coexisting attractors. This property of the system is called multistability. The final state, i.e., the attractor on which the multistable system evolves strongly depends on the initial conditions. Additionally, such systems are very sensitive towards noise and system parameters so a sudden shift to a contrasting regime may occur. To understand the dynamics of these systems one has to identify all possible attractors and their basins of attraction. Recently, it has been shown that multistability is connected with the occurrence of unpredictable attractors which have been called hidden attractors. The basins of attraction of the hidden attractors do not touch unstable fixed points (if exists) and are located far away from such points. Numerical localization of the hidden attractors is not straightforward since there are no transient processes leading to them from the neighborhoods of unstable fixed points and one has to use the special analytical-numerical procedures. From the viewpoint of applications, the identification of hidden attractors is the major issue. The knowledge about the emergence and properties of hidden attractors can increase the likelihood that the system will remain on the most desirable attractor and reduce the risk of the sudden jump to undesired behavior. We review the most representative examples of hidden attractors, discuss their theoretical properties and experimental observations. We also describe numerical methods which allow identification of the hidden attractors.
20. Automated design of complex dynamic systems.
Directory of Open Access Journals (Sweden)
Michiel Hermans
Full Text Available Several fields of study are concerned with uniting the concept of computation with that of the design of physical systems. For example, a recent trend in robotics is to design robots in such a way that they require a minimal control effort. Another example is found in the domain of photonics, where recent efforts try to benefit directly from the complex nonlinear dynamics to achieve more efficient signal processing. The underlying goal of these and similar research efforts is to internalize a large part of the necessary computations within the physical system itself by exploiting its inherent non-linear dynamics. This, however, often requires the optimization of large numbers of system parameters, related to both the system's structure as well as its material properties. In addition, many of these parameters are subject to fabrication variability or to variations through time. In this paper we apply a machine learning algorithm to optimize physical dynamic systems. We show that such algorithms, which are normally applied on abstract computational entities, can be extended to the field of differential equations and used to optimize an associated set of parameters which determine their behavior. We show that machine learning training methodologies are highly useful in designing robust systems, and we provide a set of both simple and complex examples using models of physical dynamical systems. Interestingly, the derived optimization method is intimately related to direct collocation a method known in the field of optimal control. Our work suggests that the application domains of both machine learning and optimal control have a largely unexplored overlapping area which envelopes a novel design methodology of smart and highly complex physical systems.
1. Automated design of complex dynamic systems.
Science.gov (United States)
Hermans, Michiel; Schrauwen, Benjamin; Bienstman, Peter; Dambre, Joni
2014-01-01
Several fields of study are concerned with uniting the concept of computation with that of the design of physical systems. For example, a recent trend in robotics is to design robots in such a way that they require a minimal control effort. Another example is found in the domain of photonics, where recent efforts try to benefit directly from the complex nonlinear dynamics to achieve more efficient signal processing. The underlying goal of these and similar research efforts is to internalize a large part of the necessary computations within the physical system itself by exploiting its inherent non-linear dynamics. This, however, often requires the optimization of large numbers of system parameters, related to both the system's structure as well as its material properties. In addition, many of these parameters are subject to fabrication variability or to variations through time. In this paper we apply a machine learning algorithm to optimize physical dynamic systems. We show that such algorithms, which are normally applied on abstract computational entities, can be extended to the field of differential equations and used to optimize an associated set of parameters which determine their behavior. We show that machine learning training methodologies are highly useful in designing robust systems, and we provide a set of both simple and complex examples using models of physical dynamical systems. Interestingly, the derived optimization method is intimately related to direct collocation a method known in the field of optimal control. Our work suggests that the application domains of both machine learning and optimal control have a largely unexplored overlapping area which envelopes a novel design methodology of smart and highly complex physical systems.
2. Science in the community: An ethnographic account of social material transformation
Science.gov (United States)
Lee, Stuart Henry
This dissertation is about the learning and use of science at the level of local community. It is an ethnographic account, and its theoretical approach draws on actor-network theory as well as neo-Marxist practice theory and the related notion of situated cognition. This theoretical basis supports a work that focuses on the many heterogeneous transformations that materials and people undergo as science is used to help bring about social and political change in a quasi-rural community. The activities that science becomes involved in, and the hybrid formations as it encounters local issues are stressed. Learning and knowing as outcomes of community action are theorized. The dissertation links four major themes throughout its narrative: scientific literacy, representations, relationships and participatory democracy. These four themes are not treated in isolation. Different facets of their relation to each other are stressed in different chapters, each of which analyze different particular case studies. This dissertation argues for the conception of a local scientific praxis, one that is markedly different than the usual notion of science, yet is necessary for the uptake of scientific information into a community.
3. Material Protection, Accounting, and Control Technologies (MPACT): Modeling and Simulation Roadmap
Energy Technology Data Exchange (ETDEWEB)
Cipiti, Benjamin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Dunn, Timothy [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Durbin, Samual [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Durkee, Joe W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); England, Jeff [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Jones, Robert [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Ketusky, Edward [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Li, Shelly [Idaho National Lab. (INL), Idaho Falls, ID (United States); Lindgren, Eric [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Meier, David [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Miller, Michael [Idaho National Lab. (INL), Idaho Falls, ID (United States); Osburn, Laura Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pereira, Candido [Argonne National Lab. (ANL), Argonne, IL (United States); Rauch, Eric Benton [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Scaglione, John [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Scherer, Carolynn P. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sprinkle, James K. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Yoo, Tae-Sic [Idaho National Lab. (INL), Idaho Falls, ID (United States)
2016-08-05
The development of sustainable advanced nuclear fuel cycles is a long-term goal of the Office of Nuclear Energy’s (DOE-NE) Fuel Cycle Technologies program. The Material Protection, Accounting, and Control Technologies (MPACT) campaign is supporting research and development (R&D) of advanced instrumentation, analysis tools, and integration methodologies to meet this goal. This advanced R&D is intended to facilitate safeguards and security by design of fuel cycle facilities. The lab-scale demonstration of a virtual facility, distributed test bed, that connects the individual tools being developed at National Laboratories and university research establishments, is a key program milestone for 2020. These tools will consist of instrumentation and devices as well as computer software for modeling. To aid in framing its long-term goal, during FY16, a modeling and simulation roadmap is being developed for three major areas of investigation: (1) radiation transport and sensors, (2) process and chemical models, and (3) shock physics and assessments. For each area, current modeling approaches are described, and gaps and needs are identified.
4. Terahertz dynamic scanning reflectometry of soldier personal protective material
Science.gov (United States)
Rahman, Anis; Mentzer, Mark
2012-02-01
Ballistic characterization of improved materials for Soldier personal protective equipment is an ever-challenging task, requiring precise measurement of materials during ballistic impact. Current dynamic deformation technologies, such as high-speed digital image correlation, and laser velocimetry and vibrometry, are only able to provide surface measurements. However, there is a need to measure the dynamic delamination and mass loss of composite material, allowing calculation of available kinetic energy remaining in the material. A high sensitivity terahertz dynamic scanning reflectometer may be used to measure dynamic surface deformation and delamination characteristics in real-time. A number of crucial parameters can be extracted from the reflectance measurements such as dynamic deformation, propagation velocity, and final relaxation position. As proof of principle, an acrylic plate was struck with a blunt pendulum impactor and dynamic deformation was captured in real-time. Reflectance kinetics was converted to deformation and the velocity was calculated from the kinetics spectrum. Kinetics of a focused pendulum impactor on a steel plate was also acquired, characterizing plate relaxation from maximum deformation to equilibrium with discernible vibrations before reaching stable equilibrium.
5. Systems and methods for treating material
Science.gov (United States)
Scheele, Randall D; McNamara, Bruce K
2014-10-21
Systems for treating material are provided that can include a vessel defining a volume, at least one conduit coupled to the vessel and in fluid communication with the vessel, material within the vessel, and NF.sub.3 material within the conduit. Methods for fluorinating material are provided that can include exposing the material to NF.sub.3 to fluorinate at least a portion of the material. Methods for separating components of material are also provided that can include exposing the material to NF.sub.3 to at least partially fluorinate a portion of the material, and separating at least one fluorinated component of the fluorinated portion from the material. The materials exposed to the NF.sub.3 material can include but are not limited to one or more of U, Ru, Rh, Mo, Tc, Np, Pu, Sb, Ag, Am, Sn, Zr, Cs, Th, and/or Rb.
6. Systems and methods for treating material
Energy Technology Data Exchange (ETDEWEB)
Scheele, Randall D; McNamara, Bruce K
2014-10-21
Systems for treating material are provided that can include a vessel defining a volume, at least one conduit coupled to the vessel and in fluid communication with the vessel, material within the vessel, and NF.sub.3 material within the conduit. Methods for fluorinating material are provided that can include exposing the material to NF.sub.3 to fluorinate at least a portion of the material. Methods for separating components of material are also provided that can include exposing the material to NF.sub.3 to at least partially fluorinate a portion of the material, and separating at least one fluorinated component of the fluorinated portion from the material. The materials exposed to the NF.sub.3 material can include but are not limited to one or more of U, Ru, Rh, Mo, Tc, Np, Pu, Sb, Ag, Am, Sn, Zr, Cs, Th, and/or Rb.
7. Active Interrogation using Photofission Technique for Nuclear Materials Control and Accountability
Energy Technology Data Exchange (ETDEWEB)
Yang, Haori [Oregon State Univ., Corvallis, OR (United States)
2016-03-31
Innovative systems with increased sensitivity and resolution are in great demand to detect diversion and to prevent misuse in support of nuclear materials management for the U.S. fuel cycle. Nuclear fission is the most important multiplicative process involved in non-destructive active interrogation. This process produces the most easily recognizable signature for nuclear materials. In addition to thermal or high-energy neutrons, high-energy gamma rays can also excite a nucleus and cause fission through a process known as photofission. Electron linear accelerators (linacs) are widely used as the interrogating photon sources for inspection methods involving photofission technique. After photofission reactions, prompt signals are much stronger than the delayed signals, but it is difficult to quantify them in practical measurements. Delayed signals are easily distinguishable from the interrogating radiation. Linac-based, advanced inspection techniques utilizing the delayed signals after photofission have been extensively studied for homeland security applications. Previous research also showed that a unique delayed gamma ray energy spectrum exists for each fissionable isotope. In this work, high-energy delayed γ-rays were demonstrated to be signatures for detection, identification, and quantification of special nuclear materials. Such γ-rays were measured in between linac pulses using independent data acquisition systems. A list-mode system was developed to measure low-energy delayed γ-rays after irradiation. Photofission product yields of 238U and 239Pu were determined based on the measured delayed γ-ray spectra. The differential yields of delayed γ-rays were also proven to be able to discriminate nuclear from non-nuclear materials. The measurement outcomes were compared with Monte Carlo simulation results. It was demonstrated that the current available codes have capabilities and limitations in the simulation of photofission process. A two
8. Complex and adaptive dynamical systems a primer
CERN Document Server
Gros, Claudius
2013-01-01
Complex system theory is rapidly developing and gaining importance, providing tools and concepts central to our modern understanding of emergent phenomena. This primer offers an introduction to this area together with detailed coverage of the mathematics involved. All calculations are presented step by step and are straightforward to follow. This new third edition comes with new material, figures and exercises. Network theory, dynamical systems and information theory, the core of modern complex system sciences, are developed in the first three chapters, covering basic concepts and phenomena like small-world networks, bifurcation theory and information entropy. Further chapters use a modular approach to address the most important concepts in complex system sciences, with the emergence and self-organization playing a central role. Prominent examples are self-organized criticality in adaptive systems, life at the edge of chaos, hypercycles and coevolutionary avalanches, synchronization phenomena, absorbing phase...
9. Dynamical Systems and Motion Vision.
Science.gov (United States)
1988-04-01
TASK Artificial Inteligence Laboratory AREA I WORK UNIT NUMBERS 545 Technology Square . Cambridge, MA 02139 C\\ II. CONTROLLING OFFICE NAME ANO0 ADDRESS...INSTITUTE OF TECHNOLOGY ARTIFICIAL INTELLIGENCE LABORATORY A.I.Memo No. 1037 April, 1988 Dynamical Systems and Motion Vision Joachim Heel Abstract: In this... Artificial Intelligence L3 Laboratory of the Massachusetts Institute of Technology. Support for the Laboratory’s [1 Artificial Intelligence Research is
10. Coupled dynamic systems and Le Chatelier's principle in noise control
Science.gov (United States)
Maidanik, G.; Becker, K. J.
2004-05-01
Investigation of coupling an externally driven dynamic system-a master dynamic system-to a passive one-an adjunct dynamic system-reveals that the response of the adjunct dynamic system affects the precoupled response of the master dynamic system. The responses, in the two dynamic systems when coupled, are estimated by the stored energies (Es) and (E0), respectively. Since the adjunct dynamic system, prior to coupling, was with zero (0) stored energy, E0s=0, the precoupled stored energy (E00) in the master dynamic system is expected to be reduced to (E0) when coupling is instituted; i.e., one expects E0dynamic system would result from the coupling. It is argued that the change in the disposition of the stored energies as just described may not be the only change. The coupling may influence the external input power into the master dynamic system which may interfere with the expected noise control. Indeed, the coupling may influence the external input power such that the expected beneficial noise control may not materialize. Examples of these kinds of noise control reversals are cited.
11. Dynamic Failure of Materials: A Review
Science.gov (United States)
2010-08-01
condensed matter. The VISAR is an extension of the Michelson Interferometer , and the working principles are based on Doppler shift, i.e., due to the...Velocity Interferometer System for Any Reflector (VISAR). The pull back velocity obtained from the velocity profile of the back face velocity is used...from the fiber and matrix constituents to the macro- scale through a set of internal state variables. One principal advantage of CDM is that it
12. Materials management in an internationally safeguarded fuels reprocessing plant
Energy Technology Data Exchange (ETDEWEB)
Hakkila, E.A.; Baker, A.L.; Cobb, D.D.
1980-04-01
The following appendices are included: aqueous reprocessing and conversion technology, reference facilities, process design and operating features relevant to materials accounting, operator's safeguards system structure, design principles of dynamic materials accounting systems, modeling and simulation approach, optimization of measurement control, aspects of international verification problem, security and reliability of materials measurement and accounting system, estimation of in-process inventory in solvent-extraction contactors, conventional measurement techniques, near-real-time measurement techniques, isotopic correlation techniques, instrumentation available to IAEA inspectors, and integration of materials accounting and containment and surveillance. (DLC)
13. Modeling Of Z-Pinch Dynamics With Taking Into Account The Generation Of Turbulent/Chaotic Magnetic Fields
Science.gov (United States)
Vikhrev, V. V.; Baronova, E. O.
2006-01-01
Pinch dynamics is described, which takes into account generation of turbulent magnetic fields. Turbulent/chaotic magnetic fields (TMF) appear due to MHD and kinetic instabilities. It is shown, that TMF arises near the moment of maximal compression and essentially affects plasma dynamics at the expansion stage.
14. A Transverse Dynamic Deflection Model for Thin Plate Made of Saturated Porous Materials
Science.gov (United States)
Feng-xi, Zhou; Xiao-lin, Cao
2016-10-01
In this article, a transverse dynamic deflection model is established for thin plate made of saturated porous materials. Based on the Biot's model for fluid-saturated porous media, using the Love-Kirchhoff hypothesis, the governing equations of transverse vibrations of fluid-saturated poroelastic plates are derived in detail, which take the inertial, fluid viscous, mechanical couplings, compressibility of solid, and fluid into account. The free vibration and forced vibration response of a simply supported poroelastic rectangular plate is obtained by Fourier series expansion method. Through numerical examples, the effect of porosity and permeability on the dynamic response, including the natural frequency, amplitude response, and the resonance areas is assessed.
15. Dynamic reconstruction of heterogeneous materials and microstructure evolution.
Science.gov (United States)
Chen, Shaohua; Li, Hechao; Jiao, Yang
2015-08-01
Reconstructing heterogeneous materials from limited structural information has been a topic that attracts extensive research efforts and still poses many challenges. The Yeong-Torquato procedure is one of the most popular reconstruction techniques, in which the material reconstruction problem based on a set of spatial correlation functions is formulated as a constrained energy minimization (optimization) problem and solved using simulated annealing [Yeong and Torquato, Phys. Rev. E 57, 495 (1998)]. The standard two-point correlation function S2 has been widely used in reconstructions, but can also lead to large structural degeneracy for certain nearly percolating systems. To improve reconstruction accuracy and reduce structural degeneracy, one can successively incorporate additional morphological information (e.g., nonconventional or higher-order correlation functions), which amounts to reshaping the energy landscape to create a deep (local) energy minimum. In this paper, we present a dynamic reconstruction procedure that allows one to use a series of auxiliary S2 to achieve the same level of accuracy as those incorporating additional nonconventional correlation functions. In particular, instead of randomly sampling the microstructure space as in the simulated annealing scheme, our procedure utilizes a series of auxiliary microstructures that mimic a physical structural evolution process (e.g., grain growth). This amounts to constructing a series auxiliary energy landscapes that bias the convergence of the reconstruction to a favored (local) energy minimum. Moreover, our dynamic procedure can be naturally applied to reconstruct an actual microstructure evolution process. In contrast to commonly used evolution reconstruction approaches that separately generate individual static configurations, our procedure continuously evolves a single microstructure according to a time-dependent correlation function. The utility of our procedure is illustrated by successfully
16. Dynamic stress intensity factor KⅢ and dynamic crack propagation characteristics of anisotropic materials
Institute of Scientific and Technical Information of China (English)
GAO Xin; WANG Han-gong; KANG Xing-wu
2008-01-01
Based on the mechanics of anisotropic materials,the dynamic propagation problem of a mode Ⅲ crack in an infinite anisotropic body is investigated.Stress,strain and displacement around the crack tip are expressed as an analytical complex function,which can be represented in power series.Constant coefficients of series are determined by boundary conditions.Expressions of dynamic stress intensity factors for a mode Ⅲ crack are obtained.Components of dynamic stress,dynamic strain and dynamic displacement around the crack tip are derived.Crack propagation characteristics are represented by the mechanical properties of the anisotropic materials,i.e.,crack propagation velocity M and the parameter α.The faster the crack velocity is,the greater the maximums of stress components and dynamic displacement components around the crack tip are.In particular,the parameter α affects stress and dynamic displacement around the crack tip.
17. Magnon-phonon interconversion in a dynamically reconfigurable magnetic material
Science.gov (United States)
Guerreiro, Sergio C.; Rezende, Sergio M.
2015-12-01
The ferrimagnetic insulator yttrium iron garnet (YIG) is an important material in the field of magnon spintronics, mainly because of its low magnetic losses. YIG also has very low acoustic losses, and for this reason the conversion of a state of magnetic excitation (magnons) into a state of lattice vibration (phonons), or vice versa, broadens its possible applications in spintronics. Since the magnetic parameters can be varied by some external action, the magnon-phonon interconversion can be tuned to perform a desired function. We present a quantum theory of the interaction between magnons and phonons in a ferromagnetic material subject to a dynamic variation of the applied magnetic field. It is shown that when the field gradient at the magnetoelastic crossover region is much smaller than a critical value, an initial elastic excitation can be completely converted into a magnetic excitation, or vice versa. This occurs with conservation of linear momentum and spin angular momentum, implying that phonons created by the conversion of magnons have spin angular momentum and carry spin current. It is shown further that if the system is initially in a quantum coherent state, its coherence properties are maintained regardless of the time dependence of the field.
18. Dynamic security assessment processing system
Science.gov (United States)
Tang, Lei
19. Statistical Mechanics of Dynamical Systems
Science.gov (United States)
Mori, H.; Hata, H.; Horita, T.; Kobayashi, T.
A statistical-mechanical formalism of chaos based on the geometry of invariant sets in phase space is discussed to show that chaotic dynamical systems can be treated by a formalism analogous to that of thermodynamic systems if one takes a relevant coarse-grained quantity, but their statistical laws are quite different from those of thermodynamic systems. This is a generalization of statistical mechanics for dealing with dissipative and hamiltonian (i.e., conservative) dynamical systems of a few degrees of freedom. Thus the sum of the local expansion rate of nearby orbits along relevant orbit over a long but finite time has been introduced in order to describe and characterize (1) a drastic change of the structure of a chaotic attractor at a bifurcation and anomalous phenomena associated, (2) a critical scaling of chaos in the neighborhood of a critical point for the bifurcation to a nonexotic state, and a self-similar temporal structure of a critical orbit on the critical 2^∞ attractor an the critical golden tori without mixing, (3) the critical KAM torus, diffusion and repeated sticking of a chaotic orbit to a critical torus in hamiltonian systems. Here a q-phase transition, analogous to the ferromagnetic phase transition, plays an important role. They are illustrated numerically and theoretically by treating the driven damped pendulum, the driven Duffing equation, the Henon map, and the dissipative and conservative standard maps. This description of chaos breaks the time-reversal symmetry of hamiltonian dynamical laws analogously to statistical mechanics of irreversible processes. The broken time-reversal symmetry is brought about by orbital instability of chaos.
20. Survivability of Deterministic Dynamical Systems
Science.gov (United States)
Hellmann, Frank; Schultz, Paul; Grabow, Carsten; Heitzig, Jobst; Kurths, Jürgen
2016-07-01
The notion of a part of phase space containing desired (or allowed) states of a dynamical system is important in a wide range of complex systems research. It has been called the safe operating space, the viability kernel or the sunny region. In this paper we define the notion of survivability: Given a random initial condition, what is the likelihood that the transient behaviour of a deterministic system does not leave a region of desirable states. We demonstrate the utility of this novel stability measure by considering models from climate science, neuronal networks and power grids. We also show that a semi-analytic lower bound for the survivability of linear systems allows a numerically very efficient survivability analysis in realistic models of power grids. Our numerical and semi-analytic work underlines that the type of stability measured by survivability is not captured by common asymptotic stability measures.
|
{"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": 0.4987328052520752, "perplexity": 3078.977752664253}, "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-2018-09/segments/1518891812932.26/warc/CC-MAIN-20180220090216-20180220110216-00418.warc.gz"}
|
https://www.clutchprep.com/chemistry/practice-problems/86573/boron-nitride-bn-exists-in-two-forms-the-first-is-a-slippery-solid-formed-from-t
|
# Problem: Boron nitride (BN) exists in two forms. The first is a slippery solid formed from the reaction of BCl 3 with NH 3, followed by heating in an ammonia atmosphere at 750 ˚C. Subjecting the first form of BN to a pressure of 85,000 atm at 1800 ˚C produces a second form that is the second hardest substance known. Both forms of BN remain solids to 3000 ˚C. Suggest structures for the two forms of BN.
⚠️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
Boron nitride (BN) exists in two forms. The first is a slippery solid formed from the reaction of BCl 3 with NH 3, followed by heating in an ammonia atmosphere at 750 ˚C. Subjecting the first form of BN to a pressure of 85,000 atm at 1800 ˚C produces a second form that is the second hardest substance known. Both forms of BN remain solids to 3000 ˚C. Suggest structures for the two forms of BN.
|
{"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": 0.8452111482620239, "perplexity": 2306.170738182404}, "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/1593655890105.39/warc/CC-MAIN-20200706042111-20200706072111-00151.warc.gz"}
|
https://www.physicsforums.com/threads/epr-experiment-with-pool-balls.12311/
|
# EPR Experiment with Pool Balls
1. Jan 9, 2004
### Tachyon son
***EPR Experiment with Pool Balls***
First of all sorry if what Im going to ask seems crazy stupid, but it is an idea that rounds my mind since I started reading about EPR subject.
As far as Ive read, you can imagine EPR with photon polarization or with particle spin. So, I have imagined it with two complementary pool balls inside a bag. One is red, the other is black.
I take one without looking at it. Then I travel, lets say, 1 lightyear distance.
Now it is when I look at the ball to see its colour. 50% probability then. Obviously, if my ball is red, the remaining one in the bag is black.
If we applicate the non locality principle, it will say that both balls were on a uncertain color until being looked. I know this is very stupid concept, because we certainly know that my ball was red all the time since my election, and the remaining one of course was black.
The point of my question is why we cant apply the same logic to the EPR experiment. If I use two electrons with spin 1 and -1 to make the experiment, they were in that state all the time since the separation! Theres no any comunication nor information travel!
2. Jan 9, 2004
### Staff: Mentor
Re: ***EPR Experiment with Pool Balls***
I assume you mean the usual kind of EPR experiment where you have two spin 1/2 particles in an entangled state where the total spin is zero.
If we just measured the spin in one and the same direction for both particles, then your model would (seem to) work. If we measure spin along the x-axis, we will always get a matching pair of answers: if particle A says up, particle B says down. You could pretend that each particle had its x-axis spin assigned to it, just like the color of your pool balls.
But things get more interesting when we measure the spin at different angles for each particle, say x-axis for one, y-axis for the other. It turns out that these spin measurements are incompatible, meaning that measuring one seems to "destroy" any value of the other. For any given measurement, you can only measure one direction of spin. You would have to extend your pool ball model to include a new variable to represent the y-axis measurement: let color be the spin in the x-direction, and (say) shape represent spin in the y-axis (round = up; cube = down). Things get even more complicated when you let the spin angle have any angle.
A more sophisticated (but still unworkable) model would just assign an "instruction set" to each particle. The instructions would tell it what to do upon encountering a measuring device for any spin direction: essentially this is a list of spin values for any direction of measurement. All the spin information rides along with each particle, so no funny business about communication or information travel.
But the bottom line is this. Nature doesn't seem to work that way! These kinds of model (your pool balls or the "instruction set" model) have been showed to lead to correlations that do not match the results of real experiments. (This is the essential content of Bell's theorem.) Quantum mechanics, on the other hand, predicts the results nicely.
This may not seem like much of an answer, since I'm basically saying: It just doesn't work. To go deeper would involve describing the spin correlations and the details of Bell's theorem.
3. Jan 9, 2004
### Swamp Thing
But suppose particle A encounters a measuring device first. So it follows the instructions and 'becomes' a particle with spin Sa. So far so good.. but now particle B, as per its version of the instructions, must assume a definite spin Sb: it has no choice. However, Sb is corelated with Sa, which in turn is a function of the kind of measurement that A has encountered, and this could be light years away at that moment.. so the 'instruction set' model would have to be nonlocal anyway.
The point being that a nonlocal "instruction set model" can be ruled out without delving into the details of Bell's theorm etc... no?
4. Jan 9, 2004
### Tachyon son
Your answers are too focused on my error concerning spin version of the experiment, thanks for repliying and clarify that.
The whole point of my question rests at the end: "Why we cant apply the same logic (of pool balls) to the EPR experiment".
In other words, non locality exists or is the polarization of photons already decided from the start of the experiment?
Last edited: Jan 9, 2004
5. Jan 9, 2004
### NateTG
The whole notion of 'instruction set' is what Bell's theorem is about. However, Bell's theorem does make some assumptions that aren't necessarily valid.
I haven't studied QM, but I am fairily convinced that the non-locality is a quirk of the theory more than it is a contradiction -- Specifically, that it is possible to construct a model of the Electron that deals with the EPR paradox without nonlocality, but that behaves identically to other predictions made by the typical QM model otherwise.
Proponents of the Consistent Histories approach to QM claim that the EPR paradox is actually like your pool ball example, but I don't know enought about it, or how it differs from the Copenhagen Interpretation to give you any further insight.
Last edited: Jan 9, 2004
6. Jan 9, 2004
### Swamp Thing
Suppose you had a wierd kind of pool ball to which you could put the question : "Are you red or black?" and it would randomly reply either "red" or "black". If two balls were corelated, then getting a "red" reply from one would guarantee a "black" reply from the other.
But now there is another question that you could ask: "Are you new or old?" (forget about the *meaning* of the answer :) If you get "new" from the first ball you are guaranteed to get "old" from the second.
Finally, a ball that has replied "red" once will stick to this answer as long as you stick to the same question; but if you ask a "red" ball the old-new question, you will randomly get "old" or "new".
If you ask "red or black" of a "new" ball you will get a random reply, either "red" or "black".
If you alternate your questions successively, there is a fair chance that a ball that once said "red" will now say "black".
NOW, in order to preserve the correlation between the two pool balls, it is clear that the second must know what question you asked the first one, so that it will know whether to randomize or not. As I understand it, it is this information that 'travels' nonlocally in the 'instruction set' model. Once this information is available, the second ball can follow the instructions to produce the corelated answer. If you discard the instruction set concept, then the answer itself must travel nonlocally.
(Corrections welcome!)
Last edited: Jan 9, 2004
7. Jan 20, 2004
### FZ+
Because that is what the EPR experiment invalidates.
In essence, Einstein stated that it is nonsensical to say that observing at the end changes the other ball, and that the ball must have had a state (red or black) from your election. It is simply our knowledge that is lacking. Bell then analysed this and produced the Bell inequalities, which would be true if this sort of "local realistic", hidden variable logic is true.
But experiments then carried out violated the Bell inequalities, showing this sort of thinking to be invalid. Simple as that.
8. Jan 21, 2004
### nightlight
Not quite as simple. No experiment, despite three decades of trying, has invalidated local realism. Although the "Quantum Mystery Cult" euphemistically labels this failure as "loopholes" in the existent experiments, the simple fact is that only the "data" adjusted (cherry picked, for non-QMC members) using various convenient rationalizations (additional "assumptions" such as "fair" sampling, "accidental" coincidence subtractions, non-enhancement,... etc ) violate Bell inequalities.
The unadjusted data not only has not violated the inequalities, but there are even plausible classical theories (such as "stochastic electrodynamics" for photons and Barut's self-field electrodynamics for fermions) which reproduce the actual data of all EPR experiments so far.
Last edited: Jan 21, 2004
9. Jan 21, 2004
### DrChinese
Harsh words, and not really accurate. Following the standard Copenhagen Interpretation of QM does not qualify one as a member of the "Quantum Mystery Cult." Your spirit is misplaced.
The fact is that decades of experiments have soundly supported the predictions of QM, and have failed to indicate the existence of a more complete specification of reality as discussed in EPR. To the vast majority of scientists in the area, the matter is reasonably settled by the experiments of Aspect et al. Local reality is rejected by experiment.
What is true is that there have and will continue to be those to whom the experiements leave some amount of room for a "way out". For years, the criticism was leveled at Aspect that the observer and subject systems were in communication. He fixed that criticism. Lately, there has been a criticism on the grounds of counting inefficiency.
I could certainly agree that further refinement of the experiments to answer such criticism is warranted. I don't expect anything radical or surprising to occur, but you never know.
10. Jan 21, 2004
Staff Emeritus
He is referring to criticisms of the Aspect and other experiments directed at showing the Bell inequality violation by quantum mechanics. There are some weaknesses that even quantum physicists recognize, and the "reality" partisans have chosen to make a stand on these.
11. Jan 21, 2004
### nightlight
The fact is that decades of experiments have soundly supported the predictions of QM,
No one is arguing against the QM statistical predictions. The argument is against the unsubstantiated claims that the experiments exclude local realism. To arrive at that "conclusion" the data has to be cherry picked based on metaphysical and unverified (or unverifiable) ad hoc rules.
For example, in all the experiments there is a "fair sampling" assumption -- an assumption which implies that the local hidden variables do not affect the probability of detection. Under such assumption all that the experiment excludes are the local hidden variables which don't affect the probability of detector trigger.
Check for example the paper by Emilio Santos which explains why "fair sampling" is an absurd assumption.
To the vast majority of scientists in the area, the matter is reasonably settled by the experiments of Aspect et al. Local reality is rejected by experiment.
The experiments still show only that certain absurdly restricted (as Santos explains in the paper above) types of local realism are excluded. Perfectly plausible local realistic theories, such as stochastic electrodynamics (e.g. check papers by Emilio Santos & Trevor Marshall for details) fit the actual data as well as QM.
What is true is that there have and will continue to be those to whom the experiements leave some amount of room for a "way out".
I suppose all the past inventors of "perpetuum mobile" machines could claim the same about the non-believers -- except for that little glitch with friction, which is entirely due to the present technological imperfections, and which we will fix in the near future, the machine runs for ever (even though it actually stops). The doubters are merely looking for "unimportant" loopholes and "wiggle room." Yeah, sure. It either works or it doesn't.
For years, the criticism was leveled at Aspect that the observer and subject systems were in communication. He fixed that criticism.
That was a fake "criticism" by the supporters of the QMC, not the opponents. No one was proposing models, much less theories, which would explain the optical experiments that way (via distant subluminal communication between the two far apart sides of the aparatus). The Aspect's "fix" was thus like a magician theatrically rolling up his coat sleeves, after a "neutral" voice from the public shouted about the card hiding in the sleeve.
Lately, there has been a criticism on the grounds of counting inefficiency.
The inefficiency problem better known under the euphemism "detection loophole" has been a known problem well before Aspect did his thesis. It hasn't been fixed.
Last edited: Jan 21, 2004
12. Jan 22, 2004
### DrChinese
Nice paper by Santos, BUT...
1. It is a new paper, and hardly the last word. Certainly would not be considered authoritative at this point. However, I will accord it the courtesy of addressing it on its merits.
2. Bell's Inequalities: I did not take away from the Santos paper any real criticism of the Bell derivation. In a "perfect world", the Inequality could be used to rule out all LHV theories. I disagree with the notion that Bell's "second part" (per the paper) is confused in some way. All I can see is the criticism that an actual "loophole free" experimental setup was not described. Hardly a reasonable critique of Bell by any common standard. Bell did his job fully.
3. The Aspect-type experimental setup and the "fair sampling" assumption:
Santos states:
"In the context of LHV theories the fair sampling assumption is, simply, absurd. In fact, the starting point of any hidden variables theory is the hypothesis that quantum mechanics is not complete, which essentially means that states which are considered identical in quantum theory may not be really identical. For instance if two atoms, whose excited states are represented by the same wave-function, decay at different times, in quantum mechanics this fact may be attributed to an ”essential indeterminacy”, meaning that identical causes (identical atoms) may produce different effects (different decay times). In contrast, the aim of introducing hidden variables would be to explain the different effects as due to the atomic states not being really identical, only our information (encapsuled in the wave-function) being the same for both atoms. That is, the essential purpose of hidden variables is to attribute differences to states which quantum mechanics may consider identical. Therefore it is absurd to use the fair sampling assumption -which rests upon the identity of all photon pairs- in the test of LHV theories, because that assumption excludes hidden variables a priori.
"For similar arguments it is not allowed to subtract accidental coincidences, but the raw data of the experiments should be used. In fact, what is considered accidental in the quantum interpretation of an experiment might be essential in a hidden variables theory."
There are some pretty big claims here, and I don't think they are warranted. Fair sampling is far from an absurd assumption. There has never been a single experimental test of a quantum variable which has even slightly hinted at the existence of a deeper level of reality than is currently predicted by QM. Hardly what I would call "absurd". You might as well call the notion that the sun will rise tomorrow as absurd.
You might say that it is an unwarranted or burdensome requirement. But I don't even follow that line of reasoning. Clearly, the requirement is that a LHV theory otherwise provide identical predictions to QM. Fair sampling fits this naturally. In the view of Santos, not only are the Bell Inequalities not violated in the Aspect experiments, but a new and previously unknown hidden local quantum observable is rearing its head. And somehow this observable only shows itself during this type of experiment, and no others. That observable is one in which the photon detection is suppressed or enhanced just enough to appear to match the predictions of QM (i.e. outside of the Bell Inequality); while actually falling within the statistical range of the Inequality. That's a big step, one which I might reasonably expect to have been noticed previously.
4. I have not had time to otherwise anaylze the formula logic of the paper. I will take a look at that.
A degree of skepticism is good, and healthy. I don't see the point of insults.
Last edited: Jan 22, 2004
13. Jan 22, 2004
### nightlight
1. It is a new paper, and hardly the last word. Certainly would not be considered authoritative at this point. However, I will accord it the courtesy of addressing it on its merits.
That particular paper is new, but Santos, Marshall, Jaynes and others have been criticizing the EPR-Bell experiment claims since the late 70s (check listings there, there are at least couple dozen papers by Marshall-Santos group). This wasn't merely a critique based on artificial narrow counterexamples for the particular experimental claims but a full fledged local realistic theory of quantum optics phenomena (stochastic electrodynamics; it falls short for the massive particles although the Barut's self-field electrodynamics covers fermions as well as QED to the orders it was computed).
Regardless of the ultimate value of stochastic electrodynamics as an alternative theory (it is incomplete as it stands), the mere existence of a local fields model for the actual EPR-Bell experimental data plainly demonstrates that the claims that any local realistic mechanism is being excluded by the experiments is false.
2. Bell's Inequalities: I did not take away from the Santos paper any real criticism of the Bell derivation.
The Santos-Marshall group makes distinction between the QM dynamics, which they accept, and the "measurement theory" (the non-dynamical, mystical part - projection postulate) which they reject. The Bell's theorem needs a collapse of the remote state to achieve its locality violation. They reject such collapse and point out that it hasn't been demonstrated by the experiments.
The problem nowdays with challenging the general state collapse hypothesis (projection postulate) is that it is a key ingredient necessary for Quantum Computing to work. If it is not true in the full generality, the QC won't work any better than a classical analog computer. Thus the challenge is not merely against ideas but against the funding draw QC has, a sure recipe to get yourself cut off from the leading journals and conferences. (Before the QC hype, there was a healthy debate and they were published in every major journal.)
There are some pretty big claims here, and I don't think they are warranted. Fair sampling is far from an absurd assumption.
In any deterministic hidden variable theory, the detection probability must by definition depend on some hidden variable value. The "fair sampling" hypothesis is thus an assumption that the hidden variable affecting the detection probability (the probability of triggering the avalanche and its timing when coincidence time-windows are used for pair detection) is independent from the hidden variables affecting the detected outcome (i.e. +/- choice).
Therefore that is all that experiments exclude -- the local theories for which the two sets of hidden variables are independent of each other. That is not true even for the most simple minded classical electrodynamics models of polarization and detection (or for stochastic electrodynamics or for Barut's self-field ED).
Thus the assumption is absurd since it helps experiments exclude something that isn't even included among the proposed alternatives. This is no different "exclusion" than the "refinements" of the experiments to use randomly varying polarizer direction (which you brought up earlier) -- it topples down its own strawman, not the actual theories being proposed by the opponents.
There has never been a single experimental test of a quantum variable which has even slightly hinted at the existence of a deeper level of reality than is currently predicted by QM. Hardly what I would call "absurd".
QM doesn't offer any "reality" deeper or otherwise. If you believe in any reality, local or not, the quantum phenomena require explanation beyond the prescriptions on how to calculate the probabilities.
You might say that it is an unwarranted or burdensome requirement. But I don't even follow that line of reasoning. Clearly, the requirement is that a LHV theory otherwise provide identical predictions to QM. Fair sampling fits this naturally.
There is no need for "unwarranted" or "burdensome" attributes in order to analyze what is it exactly that the "fair sampling" (purely mathematically) excludes -- it is an ad hoc constraint on hidden variables, which hand-waves off the table several proposed alternatives, leaving only the strawman local theories (that no one has proposed) for the experiments to refute.
For more discussion on the "fair" sampling hypothesis and the proposed simple additional experiment to test it for the existent EPR-Bell setups check the paper by G. Adenier, A. Khrennikov. I haven't seen as yet any of the several active quantum optics groups, who are claiming to have established Bell inequality violations, checking the assumption on their setup. Since the additional tests proposed are quite simple on the existent setup, it is suprising that no one has yet picked the clear cut open challenge of the above paper, especially considering that the verification of the fair sampling as proposed would eliminate all known plausible LHV theories (they all rely on "unfair" sampling). Or maybe some have tried it and the data didn't come out the way they wished, and they didn't want to be the first with the "bad" news. We'll have to wait and see.
PS: After writing the above, I contacted the authors of the cited paper and the status is that even though they had contacted all the groups which have done or plan to do EPR-Bell experiments, oddly no one was interested in testing the 'fair sampling' hypothesis.
Clearly, the requirement is that a LHV theory otherwise provide identical predictions to QM. Fair sampling fits this naturally.
As pointed out by Santos, the QM has two sharply divided components, dynamics and the measurement theory. They reject the measurement theory (in its full generality) and some of its implications. That is precisely what the Bell EPR tests were supposed to clarify - does the world behave that way. The result so far have not produced the type of distant collapse (projection of the composite state) as assumed by Bell for his inequalities.
The "fair sampling" is an assumption outside of QM (or any other theory or any experiment). The actually proposed alternative theories do not satisfy fair sampling, i.e. the hidden variables do not decouple into independent sets which separately control the detection timing and probability from variables controlling the +/- outcome.
Last edited: Jan 26, 2004
14. Jan 27, 2004
### venkat
epr without pool balls
hi tachyon son!
the problem with thinking the EPR problem wih pool balls is that there is a well defined colour for the pool ball, whether you measure it or not!
but in q.m, a particle has a defenite value for an observable only when you measure it!
in fact , this is what the original EPR paper is about! it doesn't talk anything about pool balls or about the usual thing about two particles with total spin zero sent in opposite directions(the usual stuff)
what the actual epr paper says is this..
in q.m, you can't have a particle in a state of defenite mamentum and position ...this is the position momentum uncertainity princple.
now suppose you have an entangled pair(momentum entangled, ie total momentum is zero) of particles going off in the opposite directions , and you decide to measure. now, if you measure the position of particle A( let us call it particles A and B), particle B goes to a state(eigenstate) with a well defined position.
( particle A, on which you perform the measurement also goes to an eigenstate of position.)
but suppose you decide to measure momentum instead, then particle B goes to a state with well defined momentum!
so, in fact particle B goes to an eigenstate,which depends on what you decide to measure! suppose the particles are light years apart, then, your choice of whether to measure position or momentum influences( instantaneously) a a particle which is light years away to collapse it into an eigenstate(of what you measure)!
until you make the measurement, you cannot say that the particles are in a state of position or momentum.
you can do the EPR experiment with spin as well...that version is due to Bohm or somebody....and in fact the Aspect experiment which confirmed bell's theorem was performed with the polarizationof photons! so it doesn't depend on which variable(or, in the language of q.m,observable ) you use!
that's all.[zz)]
15. Jan 27, 2004
### nightlight
Re: epr without pool balls
The Aspect's experiment, or any other attempt in over three decades of trying, have not confirmed Bell's inequality. See the above discussion of the "fair" sampling hypothesis (that all such experiments assume upfront) and what it means.
16. Jan 27, 2004
### DrChinese
Re: Re: epr without pool balls
1. The predictions of QM are confirmed by Aspect's experiments, there is no question about this point. Period.
2. The only question - as nightlight argues to the negative - is whether ALL Local Hidden Variable theories are excluded as a result of Aspect's experiments. The reference paper cited (Santos) asserts there ARE at least some LHV theories which would yield predictions in line with the results of the Aspect experiments. (Personally, I question the conclusion but am still reviewing this.)
Nightlight is pushing a point of view which is not generally accepted. It may well be right, but remains to be seen.
17. Jan 27, 2004
### nightlight
Re: Re: Re: epr without pool balls
1. The predictions of QM are confirmed by Aspect's experiments, there is no question about this point. Period.
The QM prediction which violates Bell's inequality has not been confirmed by the measured data, by Aspect or any other experiment. Only the adjusted data under:
a) "fair" sampling hypothesis
b) subtraction of "accidental" coincidences
violate Bell's inequality. Both of these assumptions are outside of QM and even though there were proposals (for over a decade, see refs in Santos & Khrennikov) for experiments to verify them, no group has reported performing them.
The theoretical prediction itself requires, among others, distant collapse of the composite state, a part of "measurement theory" of QM, which is not a generally accepted addition to the dynamical postulates of QM. The groups which reject assumptions (a) and (b), also question the "measurement theory," the distant instantaneous composite state collapse which Bell assumed. For them there is no such prediction (and everyone agrees that, so far, there is no _measured_ data confirming it).
2. The only question - as nightlight argues to the negative - is whether ALL Local Hidden Variable theories are excluded as a result of Aspect's experiments. The reference paper cited (Santos) asserts there ARE at least some LHV theories which would yield predictions in line with the results of the Aspect experiments. (Personally, I question the conclusion but am still reviewing this.)
All sides agree that not all LHV theories are excluded by the experiments. What Santos points out in the paper is that LHVs which are excluded are the most absurd subset of the conceivable LHV theories (there is no actual theory constructed, not even partial one, which satisfies "fair" sampling hypothesis), i.e. the experiment topples merely a strawman made up by the experimenter.
The actual alternative LHV theories (or the QM extensions/completions) which exist (whether they are ultimately right or wrong in their full scope), such as stochastic electrodynamics (SED) and self-field electrodynamics, are not being addressed by these experiments -- these theories are waved off by hand upfront by an ad hoc "fair sampling" assumption, which is outside QM and which somehow no one wants to put to test. These LHV theories agree perfectly with the EPR-Bell experiments (as Marshall, Santos and their sudents have shown in numerous papers).
Nightlight is pushing a point of view which is not generally accepted. It may well be right, but remains to be seen.
Among the people doing the experiments and their critics, there is no dispute as what is being excluded by the experiments themselves. They all know what the assumptions (a) and (b) sweep away upfront and they know that the actual alternatives from the opposition are not being tested. They all know they could test assumption (a) and that no one wants to report whether they have done it and what was the result.
The only disagreement on the experimental side is in the prediction what will happen as the technology improves -- the state collapse supporters believe Bell inequality will be ultimately violated as detectors improve (without "loopholes" i.e. without the need to adjust data via (a), (b) and such). The opponents believe it won't be violated.
On the theoretical side, the contention is the "measurement theory", specifically the postulate on the composite system state collapse, and there is no generally accepted single view on that. Nothing in day to day use of QM/QED depends on that postulate, so the vast majority of physicists ignore the subject altogether -- it doesn't affect their work either way. If it turns out falsified, there won't be any experimental consequences in anything anyone has done so far (the only experiment which could confirm it, excluding alternatives, would be a loophole free EPR-Bell test). The main effect would be on the EPR-Bell storyline and on the so-called Quantum Computing (which would lose its non-classical "magic" powers attributed to it by the present state collapse proponents, as being right around the corner, as soon as the 'decoherence' is taken care of and the detectors improve).
In summary, the only disagreement is in what will be measured/found in the future. What has actually been measured is known to those in the field and is not a matter of belief or taste. You only need to read carefully, bracket out the hype, euphemisms and the unspoken or footnoted limitations (which have been largely known since mid-1970s), to see that there is no actual disagreement between Santos/Marshall group and the EPR-Bell experimenters, as to what exactly has been excluded by the data and what by the additional assumptions. It is only in what will happen in the future that they can really disagree about, and the time is on the skeptics' side.
Last edited: Jan 27, 2004
18. Jan 27, 2004
### DrChinese
Re: Re: Re: Re: epr without pool balls
While I disagree with your characterization of the state of the current evidence, the above is just plain wrong.
Bell's Inequality has little or nothing to do with testing the predictions of quantum theory, although Aspect's experiments do confirm the predictions of QM as a by-product. The Bell Inequality requires only the essential beliefs in local reality and follows classical reasoning. If you accept that the two emitted photons carry a crossed polarization, the inequality can be deduced.
Quantum mechanics does not assume that the photons have definite polarization independent of their measurement. Classical reasoning requires this, and that is what leads to the Inequality, which is ultimately a reformulation of the idea that every measured permutation must have a likelihood of occurance between 0 and 100%. If this were true (which is the point being debated and which the Aspect experiments indicate are in fact false) then QM would not be a complete theory. Maybe. But it would not indicate that QM is "wrong". That could never happen, any more than you might consider Newton's gravitional laws "wrong".
On the other hand, the reason some people are so emotional about the Aspect experiments is this: once all "objections" are dealt with, all LHV theories must be excluded from consideration. They would be rendered totally untenable, essentially "wrong". So the issue has different stakes depending on which side you are on.
Aspect must be getting rather tired of hearing that his experiments have shown nothing. At any rate, I can agree that all voices are not in agreement on the interpretation of the results at this time. The most common conclusion I have heard is that locality has been violated, although that is not a strict conclusion from the results. And some, such as yourself, are not comfortable with the experimental procedure.
Fine, perhaps there is a flaw. I don't see the angle of attack, but perhaps it is there.
19. Jan 27, 2004
### nightlight
Re: Re: Re: Re: Re: epr without pool balls
Bell's Inequality has little or nothing to do with testing the predictions of quantum theory, although Aspect's experiments do confirm the predictions of QM as a by-product. The Bell Inequality requires only the essential beliefs in local reality and follows classical reasoning. If you accept that the two emitted photons carry a crossed polarization, the inequality can be deduced.
Of course it has to do -- the whole point was to produce a prediction of QM which no local deterministic theory would be able to. The QM predicition asserted by Bell was that QM would violate inequality that no local deterministic theory could violate. The whole excercise would have been pointless without the QM prediction falling on the opposite side of the Bell inequality from any LHV theory.
Quantum mechanics does not assume that the photons have definite polarization independent of their measurement.
That (the assumption of the lack of definite polarization) by itself doesn't imply violation of the Bell inequality. What does imply the violation is the projection postulate, part of the QM measurement theory, when applied to the entangled state.
Classical reasoning requires this, and that is what leads to the Inequality,
That alone, without also deducing a QM prediction which will violate inequality, would be pointless.
On the other hand, the reason some people are so emotional about the Aspect experiments is this: once all "objections" are dealt with, all LHV theories must be excluded from consideration.
Emotions have nothing to do with experimental facts. If you study this subject beyond the popular literature and hype, you can find out for yourself which class of LHV theories were excluded by the experimental data and which were excluded upfront (as not being the objective of the experiments). The status is as stated in my earlier posts (or as Santos states). If you find out that I have misclassified them (as described in previous posts), I would be glad to see the correction here.
The most common conclusion I have heard is that locality has been violated, although that is not a strict conclusion from the results. And some, such as yourself, are not comfortable with the experimental procedure.
Again, this is not a discussion of your or my inner "comfort". It is a simple straightforward question as to what has been excluded by the experimental data and what was taken out of consideration upfront. The plain fact, known to everyone in the field (since mid 1970s, although not emphasized equally by everyone) is that the "fair sampling" constraint on LHVs implies LHV theories in which the local variables determining the detection probabilities are independent of the variables determining the +/- outcome. It just happens that no such theories were constructed and that the actual LHV alternatives/extensions of QM (which can make predictions) do not satisfy the "fair sampling" constraint and their predictions agree with the experimental data.
You seem to be confusing the LHVs excludied by the experiments with those excluded by the Bell's inequality -- indeed all LHVs are excluded by the Bell inequality, i.e. all LHVs satisfy the inequality. The only problem is that what Bell claimed to be a QM prediction violating the inequality (deduced via the projection postulate and measurement "theory") has not panned out in the experiments -- no experimental data has violated the inequality despite over three decades of trying. Only the data filtered through the additional ad hoc assumptions (always the "fair sampling" and often some others), which are outside the QM and are untested on their own, violate the inequalities.
The point I brought up in this thread (along with Santos, Marshall, Barut, Jaynes, Khrenikov,... and other skeptics) is that if one looks closer at the experiments and the "fair sampling" assumption, it turns out that all the actual LHV alternatives (those actually constructed and developed, the theories making concrete predictions) are excluded by the "fair sampling" hypotheses all by itself, before any laser was turned on and before any detector counted a single count.
If you wish to draw some other line among the LHVs excluded and those not excluded by the actual data, please, go ahead (without the mixup between the QM prediction asserted by Bell and the actual experimental data). Explain what kind of LHVs does the "fair sampling" hypothesis exclude all by itself?
Lets hear your version and how does your separation line show that the experimental data (and not the "fair sampling" hypothesis) exclude the "pool ball logic" which started this thread.
Last edited: Jan 28, 2004
20. Jan 28, 2004
### DrChinese
Nightflight:
QM does not violate Bell's Inequality because the Inequality does not apply. QM makes predictions for actual experiments of photon beams with 2 polarizers. The QM prediction for a photon beam passing through both polarizers is a function only of the angle between the polarizers. The same formula applies whether you are talking about photons in an entangled state, such as the Aspect experiment measures, or a single beam passing through consecutive polarizers. In fact, the formula is the same in classical optics too, but only when light is treated like a wave.
The problem from a LHV perspective is that if the beam is postulated to have a) an orientation which exists independently of the measurement apparatus which was b) determined at the time the photon was created. These 2 conditions are too severe to survive. You don't need the Aspect setup to see that something is wrong with that anyway. It follows from experiments anyone can do with 2, 3 and more polarizers in a single beam too. I will explain in a separate post.
The Aspect experiments are simply the logical extension of the measurement process issues which were quickly evident as QM was being formulated, a la the double slit experiment. Clearly reality does not act as it does in the classical world, and I don't understand why this point is a topic of debate. Next you will be telling me that the double slit experiment does not prove anything, either. The fact is that any way you cut it, the Heisenberg Uncertainty Relations apply and there is no observable deeper level of local reality.
Similar Discussions: EPR Experiment with Pool Balls
|
{"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": 0.8265913128852844, "perplexity": 1111.6071578916562}, "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/1508187825174.90/warc/CC-MAIN-20171022094207-20171022114207-00015.warc.gz"}
|
https://www.investopedia.com/articles/fundamental/04/021104.asp
|
How do you know when a company is at risk of corporate collapse? To detect any signs of looming bankruptcy, investors calculate and analyze all kinds of financial ratios: working capital, profitability, debt levels, and liquidity. The trouble is, each ratio is unique and tells a different story about a firm's financial health. At times they can even appear to contradict each other. Having to rely on a bunch of individual ratios, the investor may find it confusing and difficult to know when a stock is going to the wall.
Tutorial: Financial Ratios
In a bid to resolve this conundrum, New York University professor Edward Altman introduced the Z-score formula in the late 1960s. Rather than search for a single best ratio, Altman built a model that distills five key performance ratios into a single score. As it turns out, the Z-score gives investors a pretty good snapshot of corporate financial health.
Z-Score Formula
The Z-score formula for manufacturing firms, which is built out of the five weighted financial ratios:
\begin{aligned} &\text{Z-Score} = (1.2 \times A) + (1.4 \times B) + (3.3 \times C) + (0.6 \times D) + (1.0 \times E)\\ &\textbf{where:}\\ &A = \text{Working Capital} \div \text{Total Assets} \\ &B = \text{Retained Earnings} \div \text{Total Assets} \\ &C = \text{Earnings Before Interest \& Tax} \div \text{Total Assets} \\ &D = \text{Market Value of Equity} \div \text{Total Liabilities} \\ &E = \text{Sales} \div \text{Total Assets} \\ \end{aligned}
Strictly speaking, the lower the score, the higher the odds are that a company is heading for bankruptcy. A Z-score of lower than 1.8, in particular, indicates that the company is on its way to bankruptcy. Companies with scores above 3 are unlikely to enter bankruptcy. Scores in between 1.8 and 3 define a gray area.
The Z-Score Explained
It's helpful to examine why these particular ratios are part of the Z-score. Why is each significant?
Working Capital/Total Assets (WC/TA)
This ratio is a good test for corporate distress. A firm with negative working capital is likely to experience problems meeting its short-term obligations because there are simply not enough current assets to cover those obligations. By contrast, a firm with significantly positive working capital rarely has trouble paying its bills.
Retained Earnings/Total Assets (RE/TA)
This ratio measures the amount of reinvested earnings or losses, which reflects the extent of the company's leverage. Companies with low RE/TA are financing capital expenditure through borrowings rather than through retained earnings. Companies with high RE/TA suggest a history of profitability and the ability to stand up to a bad year of losses.
Earnings Before Interest and Tax/Total Assets (EBIT/TA)
A version of return on assets (ROA), an effective way of assessing a firm's ability to squeeze profits from its assets before deducting factors like interest and tax.
Market Value of Equity/Total Liabilities (ME/TL)
This ratio shows that if a firm were to become insolvent, how much the company's market value would decline before liabilities exceed assets on the financial statements. This ratio adds a market value dimension to the model that isn't based on pure fundamentals. In other words, a durable market capitalization can be interpreted as the market's confidence in the company's solid financial position.
Sales/Total Assets (S/TA)
This tells investors how well management handles competition and how efficiently the firm uses assets to generate sales. Failure to grow market share translates into a low or falling S/TA.
WorldCom Test
To demonstrate the power of the Z-score, test how it holds up with a tricky test case. Consider the infamous collapse of telecommunications giant WorldCom in 2002. WorldCom's bankruptcy created \$100 billion in losses for its investors after management falsely recorded billions of dollars as capital expenditures rather than operating costs.
Calculate Z-scores for WorldCom using annual 10-K financial reports for years ending December 31, 1999, 2000 and 2001. You'll find that WorldCom's Z-score suffered a sharp fall. Also note that the Z-score moved from the gray area into the danger zone in 2000 and 2001, before the company declared bankruptcy in 2002.
But WorldCom management cooked the books, inflating the company's earnings and assets in the financial statements. What impact do these shenanigans have on the Z-score? Overstated earnings likely increase the EBIT/total assets ratio in the Z-score model, but overstated assets would shrink three of the other ratios with total assets in the denominator. So the overall impact of the false accounting on the company's Z-score is likely to be downward.
|
{"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 1, "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": 0.8464147448539734, "perplexity": 4155.289325215423}, "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-2019-22/segments/1558232257002.33/warc/CC-MAIN-20190523023545-20190523045545-00045.warc.gz"}
|
http://math.stackexchange.com/questions/301007/why-is-it-safe-to-assume-m-is-less-than-all-ns-in-h%c3%a5stads-broadcast-attack
|
# Why is it safe to assume $M$ is less than all $N$s in Håstad's Broadcast Attack
I am reading the Wikipedia article on Broadcast attack. In the proof, the editor made an assumption that $M$ is less than all $N$. Why is this assumption safe?
-
Because RSA doesn't work at all if the message is larger than the modulus.
In practical confidentiality applications, the message typically just consists of a symmetric session key and some identifying metadata, so there's plenty of room for it (plus some randomized padding to defend against the attack) within the key sizes that are needed for security anyway.
-
The Broadcast Attack is an attack on the RSA cryptosystem. The Wikipedia page on RSA has the following:
Alice transmits her public key (n, e) to Bob and keeps the private key secret. Bob then wishes to send message M to Alice. He first turns M into an integer m, such that 0 ≤ m < n ...
So it looks like that's just the standard protocol? For a more in-depth answer about why, I would have to substantially refresh my understanding of how RSA works.
-
|
{"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": 0.3979708254337311, "perplexity": 635.5994520624396}, "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-2015-18/segments/1429246658061.59/warc/CC-MAIN-20150417045738-00051-ip-10-235-10-82.ec2.internal.warc.gz"}
|
http://physics.aps.org/synopsis-for/10.1103/PhysRevLett.106.171801
|
# Synopsis: A “bump” in the data
Will hints of new physics from the study of proton-antiproton collisions stand up against further scrutiny?
Particle colliders look for physics beyond the standard model by first verifying what the model predicts and then looking for deviations. If a new unstable particle is produced, it can decay into a pair of particles whose invariant mass is equal to the mass of that particle. So one of the simplest signals for physics beyond the standard model is an excess in the invariant mass distribution of a pair of particles in the final state of a collision, colloquially called a “bump” in the distribution.
While much of the attention in the particle physics community is focused on the Large Hadron Collider (LHC), the Fermilab collider is still the second highest energy machine in the world and has data on many more collisions than the LHC. Now, from an analysis of proton-antiproton collisions, the CDF collaboration (T. Aaltonen et al.) at Fermilab reports a curious excess in the number of events where there is a $W$ boson and a pair of jets with an invariant mass in the $120$$160\phantom{\rule{0.333em}{0ex}}\text{GeV}$ range. Taking into account statistical and systematic errors, as well as the current understanding of the background, this “bump” in the data has a significance of $3.2$ standard deviations. The results are reported in Physical Review Letters.
What could the “bump” be? First, it could be a statistical fluctuation or systematic effect. But it could also result from the production and decay of a new particle. Various models for such a new particle have already been proposed, but the data does not correspond to a standard model Higgs boson (there are too many events in the “bump” for that and one would have expected more events with bottom-quark jets). So we await future analysis to pin down the nature of this intriguing feature in the data. – Robert Garisto
### Announcements
More Announcements »
## Subject Areas
Particles and Fields
## Previous Synopsis
Interdisciplinary Physics
## Next Synopsis
Particles and Fields
## Related Articles
Particles and Fields
### Synopsis: Deuterons Spin Together for a Thousand Seconds
Researchers set a new record for the in-plane spin-alignment lifetime of deuterons circulating in a magnetic storage ring. Read More »
Quantum Physics
### Synopsis: Testing Quantum Physics with Neutrinos
An experiment similar to the Bell inequality test confirms that neutrino oscillation is a quantum physics effect that is incompatible with alternative classical models. Read More »
Nuclear Physics
### Viewpoint: Of Gluons and Fireflies
Improved models of gluon fluctuations within protons have been developed and applied to particle collision data, pointing to strong gluon fluctuations at high energies. Read More »
|
{"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 10, "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": 0.7830880284309387, "perplexity": 1019.9315739579466}, "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/1469257829320.91/warc/CC-MAIN-20160723071029-00322-ip-10-185-27-174.ec2.internal.warc.gz"}
|
http://mathhelpforum.com/number-theory/198286-fermats-little-theorem-lemma-print.html
|
# Fermat's little theorem (lemma)
• May 3rd 2012, 03:24 AM
froodles01
Fermat's little theorem (lemma)
I'm doing Number Theory, completed multiplication, division etc, but now moved on to Fermat's little theorem.
Having a bit of trouble seeing how to go about a couple of examples I have.
Generally
a^(p-1) 1 (mod p)
where p is a prime number
& a is an integer
i) 3^18 divided by 19
so p=19 & a=3
3^18 1 (mod 19)
Hence remainder is 1
Fine
ii) 3^55 divided by 19
but 55 isn't a prime, so how do I do this, please?
• May 3rd 2012, 04:09 AM
a tutor
Re: Fermat's little theorem (lemma)
$3^{55}=3(3^{18})^3$
• May 3rd 2012, 04:44 AM
froodles01
Re: Fermat's little theorem (lemma)
Yes, the example solution tells me this, too & goes on two steps further which is
= 3 x 1^3
= 3 (mod19)
why is it 3x . . . . (3^18)^3
the 3x has me confused, sorry.
• May 3rd 2012, 05:23 AM
a tutor
Re: Fermat's little theorem (lemma)
I'm not sure what you are confused about. Can you clarify?
Can you see that $3^{55}=3(3^{18})^3$?
• May 3rd 2012, 05:47 AM
Deveno
Re: Fermat's little theorem (lemma)
the prime number p, in this case, is 19 (what goes in the modulus). the fact that 55 isn't prime isn't relevant.
what we DO know is that:
318 = 1 (mod 19) this is FLT with p = 19, a = 3, and p-1 = 18.
THEN we use the division algorithm to write 55 = 18q + r (divide 55 by 18, and compute the remainder).
since 18*3 = 54, we get q = 3 and r = 1:
55 = 18(3) + 1. therefore:
355 (mod 19)
= 318(3) + 1 (mod 19)
= (318(3))(31) (mod 19) (from the rules of exponents)
= (318)3(3) (mod 19)
= (318 (mod 19))3(3 (mod 19)) (the usual rules of multiplication still hold mod 19)
= (1 (mod 19))(3 (mod 19))
= (1)(3) (mod 19)
= 3 (mod 19)
• May 23rd 2012, 02:01 AM
froodles01
Re: Fermat's little theorem (lemma)
Thanks for a brilliant explanation, however I have another similar question I don't seem to be able to finish.
Could someone help with this please?
43^43 divided by 17
FLT is a^p-1 ≡ 1 (mod p)
& I know that 43 = 2*16+11
I have used the steps as in above explanation,
43^43 = 2^16(2) + 11 (mod 17)
= 2^16(2) + 11 (mod 17)
= (2^16(2))(2^11) (mod 17)
= (2^16)^2 (2)^11 (mod 17)
= (2^16 (mod 17))^2 * (2 (mod 17))^11
er. . . not quite sure what to do next.
• May 23rd 2012, 05:50 AM
Deveno
Re: Fermat's little theorem (lemma)
that's not the method i wrote.
we have, first of all, 43 = 9 (mod 17) (we reduce "a" mod p).
so 4343 = 943 (mod 17).
now 43 = (16)(2) + 11, so
943 = 9(16)(2) + 11 (mod 17)
= (916)2(911) (mod 17)
= (1)2(911) = 911 (mod 17) <---FLT used HERE (with a = 9, and p-1 = 16)
note we've done two things here: we've reduced the number being exponentiated from 43 to 9, and we've reduced the exponent from 43 to 11.
from here, we have to do things "the hard way":
92 = 81 = 13 (mod 17)
94 = (92)2 = 132 = 169 = 16 = -1 (mod 17)
98 = (94)2 = 1 (mod 17)
therefore, 911 = 98+3 = (98)(93) = (1)(93) = 93 (mod 17)
finally, 93 = (92)(9) = (13)(9) = 117 = 15 (mod 17)
hence 4343 = 15 (mod 17)
|
{"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": 0.9123123288154602, "perplexity": 2716.787841635474}, "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/1469257836392.83/warc/CC-MAIN-20160723071036-00252-ip-10-185-27-174.ec2.internal.warc.gz"}
|
http://math.stackexchange.com/questions/91253/solving-for-the-smallest-x-1-2-cdots-20-equiv-x-pmod-7
|
# Solving for the smallest $x$ : $1! + 2! + \cdots+ 20! \equiv x\pmod 7$
I know the smallest $x \in \mathbb{N}$, satisfying $1! + 2! + \cdots + 20! \equiv x\pmod7$ is $5$. I would like to know methods to get to the answer.
-
One natural question, I think, is to find the remainder when $1! + 2! + \cdots + (n-1)!$ is divided by $n$. This is oeis.org/A067462 . The problem of when this is zero is apparently of at least minor interest, according to Guy, Unsolved Problems in Number Theory: oeis.org/A057245 – Michael Lugo Dec 14 '11 at 1:49
## 1 Answer
Note that each of $7!$, $8!$, $9!,\ldots, 20!$ is congruent to $0$ modulo $7$, since they are all divisible by $7$.
Note that $6!\equiv -1\pmod{7}$ by Wilson's Theorem, which cancels $1!$.
That leaves $2!+3!+4!+5! = 2! + 3!(1 + 4 + 20)$. But $3!\equiv -1\pmod{7}$, and $20\equiv -1\pmod{7}$, so $2!+3!+4!+5! \equiv 2-(1+4-1) = -2\equiv 5\pmod{7}$.
-
It is implicit in Arturo's answer, but it is interesting to note that $1! + 2! + \cdots + n! \equiv 5$ for any $n \geq 7$. – Austin Mohr Dec 13 '11 at 22:11
+1,The problem could be solved without Wilson's theorem but it always handy to know and use these tools. – Quixotic Dec 13 '11 at 22:23
|
{"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": 0.9037041664123535, "perplexity": 223.7928302861002}, "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-2015-22/segments/1432207930423.94/warc/CC-MAIN-20150521113210-00327-ip-10-180-206-219.ec2.internal.warc.gz"}
|
https://arxiv.org/abs/0910.1181
|
gr-qc
(what is this?)
# Title: Nonsingular Dirac particles in spacetime with torsion
Abstract: We use the Papapetrou method of multipole expansion to show that a Dirac field in the Einstein-Cartan-Kibble-Sciama (ECKS) theory of gravity cannot form singular configurations concentrated on one- or two-dimensional surfaces in spacetime. Instead, such a field describes a nonsingular particle whose spatial dimension is at least on the order of its Cartan radius. In particular, torsion modifies Burinskii's model of the Dirac electron as a Kerr-Newman singular ring of the Compton size, by replacing the ring with a toroidal structure with the outer radius of the Compton size and the inner radius of the Cartan size. We conjecture that torsion produced by spin prevents the formation of singularities from matter composed of quarks and leptons. We expect that the Cartan radius of an electron, ~10^{-27} m, introduces an effective ultraviolet cutoff in quantum field theory for fermions in the ECKS spacetime. We also estimate a maximum density of matter to be on the order of the corresponding Cartan density, ~10^{51} kg m^{-3}, which gives a lower limit for black-hole masses ~10^{16} kg. This limit corresponds to energy ~10^{43} GeV which is 39 orders of magnitude larger than the maximum beam energy currently available at the LHC. Thus, if torsion exists and the ECKS theory of gravity is correct, the LHC cannot produce micro black holes.
Comments: 8 pages; published version Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Theory (hep-th) Journal reference: Phys.Lett.B690:73-77,2010; Erratum-ibid.B727:575,2013 DOI: 10.1016/j.physletb.2010.04.073 10.1016/j.physletb.2013.11.005 Cite as: arXiv:0910.1181 [gr-qc] (or arXiv:0910.1181v2 [gr-qc] for this version)
## Submission history
From: Nikodem Poplawski [view email]
[v1] Wed, 7 Oct 2009 08:12:03 GMT (4kb)
[v2] Fri, 29 Oct 2010 14:59:41 GMT (11kb)
|
{"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": 0.8728877305984497, "perplexity": 1669.9360743363084}, "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-2018-09/segments/1518891814036.49/warc/CC-MAIN-20180222061730-20180222081730-00653.warc.gz"}
|
https://www.eolymp.com:443/en/contests/16654/problems/172350
|
Competitions
# Dino and colors
Dino accidentally painted a red strip of length a on the wall of the school with red paint. Until the end of the break, it must be hidden, because if the teacher sees, then he will be very angry. Dino remembered that he had two white paints with which he can draw white stripes of length b. He wants to use these paints to hide completely the red strip with white, or to paint so that the length of the red strip on the wall will be as small as possible. Help Dino to do this.
#### Input
Two integers a and b (1a, b109).
#### Output
Print the possible minimum length of the remaining red strip.
Time limit 1 second
Memory limit 128 MiB
Input example #1
10 5
Output example #1
0
Input example #2
6 2
Output example #2
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": 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": 0.4971851110458374, "perplexity": 2500.924900730742}, "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-2022-40/segments/1664030338213.55/warc/CC-MAIN-20221007143842-20221007173842-00146.warc.gz"}
|
https://www.chemicalforums.com/index.php?topic=22012.0
|
May 31, 2020, 04:01:16 AM
Forum Rules: Read This Before Posting
### Topic: myeloma cell (Read 4831 times)
0 Members and 1 Guest are viewing this topic.
#### AhmedEzatAlzawalaty
• Full Member
• Posts: 191
• Mole Snacks: +4/-31
• Gender:
##### myeloma cell
« on: January 16, 2008, 09:47:46 PM »
how can myeloma cells and malignant cells be long-life dividing cells ?
#### Yggdrasil
• Retired Staff
• Sr. Member
• Posts: 3210
• Mole Snacks: +482/-21
• Gender:
• Physical Biochemist
##### Re: myeloma cell
« Reply #1 on: January 16, 2008, 11:13:55 PM »
Cancer is very complex and it is hard to explain fully how cancers arise. However, I can point to a great review article by Douglas Hanahan and Robert Weinberg entitled "The Hallmarks of Cancer," which goes over some of the common capabilities that cancer cells need to acquire in order to proliferate uncontrollably. The article points to six "Hallmarks of Cancer." First, the cells need to grow in the absence of a growth signal (often through activation of oncogenes). Second, the cells need to be unresponsive to anti-growth signals. Third, since the immune system targets abnormal cells, cancer cells need to evade the immune system by disabling apoptosis (programmed cell-death). Hallmarks two and three are often accomplished through inactivation of tumor-suppressor genes. Fourth, in order to feed themselves, cancer cells need to promote angiogenesis, the formation of new blood vessels. The combination of these factors and others (e.g. telomerase activation and inhibition of signalling through cell adhesion molecules) give cancer cells unlimited replicative abilities and the ability to metathesize (the fifth and sixth hallmarks of cancer).
Hanahan, D. & Weinberg, R.A. The Hallmarks of Cancer. Cell 100, 57-70 (2000).
http://dx.doi.org/10.1016/S0092-8674(00)81683-9
|
{"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": 0.886506974697113, "perplexity": 13080.216161839488}, "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-2020-24/segments/1590347411862.59/warc/CC-MAIN-20200531053947-20200531083947-00313.warc.gz"}
|
http://openstudy.com/updates/4e349f420b8ba7b2da422d20
|
## Got Homework?
### Connect with other students for help. It's a free community.
• across
Online now
• laura*
Helped 1,000 students
Online now
• Hero
College Math Guru
Online now
Here's the question you clicked on:
55 members online
• 0 viewing
## TransendentialPI Group Title How do you find the inverse of h(x) = x + x^0.5? I understand how to switch x and y, but how can we isolate the y? 3 years ago 3 years ago Edit Question Delete Cancel Submit
• This Question is Closed
1. malevolence19 Group Title
Best Response
You've already chosen the best response.
1
The inverse is: $\frac{1}{2}(-2y-1)\pm \frac{1}{2}\sqrt{4y+1}$
• 3 years ago
2. TransendentialPI Group Title
Best Response
You've already chosen the best response.
0
Thanks. Did you use software to get this? I'm needing to do this by hand. h(x) looks to be one to one and looking at the derivatives it looks like h(x) is one to one. I'll keep looking, thanks.
• 3 years ago
3. TransendentialPI Group Title
Best Response
You've already chosen the best response.
0
I was helping someone with this exercise. They left out the fact we were looking for $h ^{-1}(6)$ given $h(x)=x+\sqrt x$ Here is what I came up with: This is asking when does h(x) = 6 6 = x + x^.5 0= x + x^.5 -6 factors to 0=(x^.5 + 3)(x^.5 - 2) x = 9 and x = 4 Checking in the original and by looking at the graph of h, we see the only place h(x) = 6 is at x = 4. h-1(6)=4 Maybe this will help someone some time.
• 3 years ago
• Attachments:
## See more questions >>>
##### spraguer (Moderator) 5→ View Detailed Profile
23
• Teamwork 19 Teammate
• Problem Solving 19 Hero
• You have blocked this person.
• ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.
|
{"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": 0.9666329622268677, "perplexity": 2989.2845208791996}, "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-2014-23/segments/1406510274581.53/warc/CC-MAIN-20140728011754-00109-ip-10-146-231-18.ec2.internal.warc.gz"}
|
https://ask.sagemath.org/answers/14089/revisions/
|
• removing the files SAGE_ROOT/local/bin/R and SAGE_ROOT/local/bin/Rscript, and creating instead (symbolic) links pointing to the R installation you want to use.
• do similarly with the directory SAGE_ROOT/local/lib/R/
|
{"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": 0.2535165846347809, "perplexity": 13505.272036172724}, "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-2021-21/segments/1620243989820.78/warc/CC-MAIN-20210518033148-20210518063148-00210.warc.gz"}
|
http://www.sciforums.com/threads/why-do-men-shout-at-women-in-the-street.107142/
|
# Why do men shout at women in the street?
Discussion in 'Human Science' started by Stryder, Mar 25, 2011.
1. ### StryderKeeper of "good" ideas.Valued Senior Member
Messages:
13,102
I haven't suffered this too much myself being a guy, occasionally maybe a drunken girl probably not squinting correctly through one eye, but for the most part it's not something that occurs to men too often.
The same can be said of groping (although again, there's been times I've been nipped, poked or cupped), being a guy however I pretty much ignored the instances, I didn't complain or "follow" things up, I just assumed that certain people under the influence of alcohol can sometimes lose self-control and do things spontaneously.
For women however it can be a threatening experience if they have men call, taunt or grope and it's something that various groups are reportedly trying to stop.
The group mentioned is located at http://www.stopstreetharassment.com
I thought I would bring this to light for both discussion and because I know that a few women that post here might well want to know about this if they didn't already.
In any case a question to kickstart discussion is already quoted:
Why do men shout at women in the street?
Last edited: Mar 25, 2011
3. ### DeeCeeValued Senior Member
Messages:
1,793
Could we change that to..
"Why do idiots shout at women in the street?"
Gender neutral, more accurate and don't make me feel bad for being a bloke.
Dee Cee
5. ### Me-Ki-GalBannedBanned
Messages:
4,634
Well for Me it is when I see someone I know I yell out Hey Lauren Wait up !! Where you going ? Did you get that E-mail I sent you ? Is it doable ?
7. ### sifreak21Valued Senior Member
Messages:
1,671
i saw a couple the other day some @%## was yelling at some @#$^&$% across the street it was quite funny. the guy was just walkin she was mirrioring him on the other side of the street
8. ### StryderKeeper of "good" ideas.Valued Senior Member
Messages:
13,102
That is indeed true, obviously I titled this based upon the gender bias of the initial report and/or group. As I mentioned though it can occur to either gender, obviously though women are more victimised by it.
To be honest though I doubt you felt bad for being a bloke, you just felt bad there are "idiots" that happened to be blokes.
That's Empathetic of you, something that those "idiots" wouldn't understand.
9. ### StryderKeeper of "good" ideas.Valued Senior Member
Messages:
13,102
Well that's dependent on if "Lauren" wants the world to know her name and if her steps get faster in a way to evade. In essence if she's a friend that you should be able to approach her civilly without asking her to "get her breasts out" or telling her that you "want to rump-ride her (possibly including the word "sore" here)". (This incidentally aren't things I would state, but things I have commonly heard yelled)
10. ### drumbeatRegistered Senior Member
Messages:
375
Why do people shout at other people in the street?
It's nothing to do with women or men.
11. ### Me-Ki-GalBannedBanned
Messages:
4,634
I don't know if that is true or not . Perceptions of female / male rolls by gender pigion holing plays a big roll in what is unacceptable behavior . Where as if the same act was commented on a Man the thought of the day would be that there is no victim status for the Man . This is in the process of change though, were as the culture in America is moving towards aggressive behavior in the feminine side of society and the male side is taking on an opposite roll also . I first noticed the change in the school girls when my daughters where growing and progressively the girls where taking on aggressive fight instead of flight attitudes . They would follow through on viciousness more often than there male counterparts . The Guys would lay back and say Wo check that out. The trend was national too and still might be .
12. ### BellsStaff Member
Messages:
23,019
I think it is more the:
"Hey luv, show us ya tits"..
And the:
"Wanna ride my pole?"..
Or the:
"Bend over so I can do you standing up"..
I hear comments like that every morning when I'd go to work from slack jawed construction workers who work on the various projects that are always underway in a city. And they do it to most women who are unfortunate to have to walk past there to get to their own buildings to work.
Why they do it? I have no idea.
I have discovered that an ipod and the volume turned up loudly works wonders.
13. ### Me-Ki-GalBannedBanned
Messages:
4,634
I might whisper that in her ear . Maybe if she wanted Me to say it louder I would have to do it. I am a slave dude . I have to do what my female Goddesses ask . I have no choice if I want to live
14. ### Me-Ki-GalBannedBanned
Messages:
4,634
O.K. your talking about Me again !! We are cave animals with beastly lust from all the testosterone flowing threw our blood by the physical work that we do. Now once and a while a girl ends up on the crew , not something most women will do . It takes a women with true grit to work in the construction industry, but The woman that suffers through the indignation of construction vulgarities wins the respect of the working class that leads a life of danger day by day . Yeah construction is an occupation pit with hazards and the vulgarly is one way the set group deals with the physical pain of day to day tasking . You should hear how we talk to our buddy worker right next to us . The dog is getting sore if anyone out there understands that bit of lingo
15. ### BellsStaff Member
Messages:
23,019
So she wins the respect of her co-workers if she ignores the sexual harassment from her co-workers?
Okay...
That is an interesting way to put it I guess.
16. ### DeeCeeValued Senior Member
Messages:
1,793
I try to be none judgemental but seeing as I'm currently a christian I feel entitled to.
Men who sexually harrass women (for thats what it is) in the street are common folk who lack breeding they are also almost certainly atheists.
On the other hand I once had a friend who quiet openly asked women for sex within minutes of being introduced. Theory being, if only one in a hundred women would be prepared to entertain congress with him then statistically he only need ask 100 women a day to be assured daily coitus.
Strange to say it seemed to work for him.
I once saw him ask a girl he had met ten minutes previous "I'm going to the toilet, you commin' with me?" She went.
It's about time women recognised their power and brought men into line.
Don't go to the toilet with us that just makes us worse.
Dee Cee EO & Gee
Last edited: Mar 25, 2011
17. ### visceral_instinctMonkey see, monkey denigrateValued Senior Member
Messages:
7,913
Because they're fucking worthless knockoffs who don't deserve the term human being.
The thing that pisses me off is when young adolescent boys do it. At least a grown man has some 20 kilograms on me. Of course he's not intimidated by my 'Fuck off and die'. Why would he be? But the added arrogance of a smaller, weaker KID doing it, assuming that just because he is male and I am female he is the powerful one and I am some sort of prey animal even though he's lighter, weaker and younger...Fuck. I had a 13-14ish boy do this with his friends when I went to use a public toilet. I just looked at this fucking child, this little weed who must have had less testosterone in him than I have at his age, assuming the role of powerful/dominant hunter and thinking I must be some sort of little victim because I was a woman...I wanted to hurt that thing so bad. I wanted to fucking pull his limbs off one by one.
18. ### livingin360Registered Senior Member
Messages:
182
are you talking about people that shout stuff like damn girl!?
19. ### chimpkinC'mon, get happy!Registered Senior Member
Messages:
4,416
I think it's a combo of two things: Male privilege and testosterone.
They can get away with being obscene without being looked down on or getting attacked-in fact it probably raises their status in the eyes of the guys around them.
This part may be a projection of what I feel when it happens to me, though...and guys may or may not mean it like this:
It's as if they are saying: "You may think you're important, and have a good job, but you're just a piece of meat, and I can come get you, like it or not."
So an expression of dominance and a threat.
Also, guys really do think about sex all the time. Even the nice ones. It's the testosterone, it does that.
20. ### visceral_instinctMonkey see, monkey denigrateValued Senior Member
Messages:
7,913
No.
About little shits who shout sexual things at me and think that even though I'm older, heavier and stronger I'm their little helpless victim and they own the world because they're male.
21. ### Me-Ki-GalBannedBanned
Messages:
4,634
There has never been sexual harassment on any Job I have been on in my life time of more than 40 years of building. It just don't happen . If it does you will be down the road so fast you will wonder how we cut your check so fast because even the fastest of computers are slower than the time it hit your hand . Vulgarity in construction is part of the developed language of the business and is part of the tasking and if you don't understand the language you are not going to be in the construction industry long . Now my wife when she worked for Washington Corp she would make the guys put a quarter in a jug when ever they used the word Fuck and she replaced it with the word combo of Fire Truck and the Men obeyed the rule as it was a game there minds could relate to. That was one word on one crew . It is a daunting task to root out the whole vocabulary used on jobs in the entire industry , but hey if the rest of the world wants to legislate it with all the other ridiculous legislation going on power to the people
22. ### visceral_instinctMonkey see, monkey denigrateValued Senior Member
Messages:
7,913
I have a very high sex drive. I also have a natural revulsion at the idea of violating someone's boundaries like that.
I remember being 16 and sitting in the same room as a guy I liked at a young people's activity and feeling so rabidly horny I thought I might black out. But you didn't see me bother him. I didn't even talk to him.
23. ### visceral_instinctMonkey see, monkey denigrateValued Senior Member
Messages:
7,913
It's not the word fuck that is the problem, nor other curse words. You can say shit every other word and still not threaten someone or violate their boundaries.
|
{"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": 0.15457236766815186, "perplexity": 3226.2363929574844}, "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/1568514572436.52/warc/CC-MAIN-20190915215643-20190916001643-00465.warc.gz"}
|
https://opus.bibliothek.uni-wuerzburg.de/frontdoor/index/index/searchtype/all/rows/20/institutefq/Theodor-Boveri-Institut+f%C3%BCr+Biowissenschaften/doctypefq/article/yearfq/2012/start/2/author_facetfq/Schn%C3%B6lzer%2C+Martina/sortfield/title/sortorder/desc/docId/12728
|
• search hit 3 of 3
Back to Result List
## A truncated lamin A in the Lmna$$^{−/−}$$ mouse line: Implications for the understanding of laminopathies
Please always quote using this URN: urn:nbn:de:bvb:20-opus-127281
• During recent years a number of severe clinical syndromes, collectively termed laminopathies, turned out to be caused by various, distinct mutations in the human LMNA gene. Arising from this, remarkable progress has been made to unravel the molecular pathophysiology underlying these disorders. A great benefit in this context was the generation of an A-type lamin deficient mouse line (Lmna$$^{−/−}$$) by Sullivan and others,1 which has become one of the most frequently used models in the field and provided profound insights to many differentDuring recent years a number of severe clinical syndromes, collectively termed laminopathies, turned out to be caused by various, distinct mutations in the human LMNA gene. Arising from this, remarkable progress has been made to unravel the molecular pathophysiology underlying these disorders. A great benefit in this context was the generation of an A-type lamin deficient mouse line (Lmna$$^{−/−}$$) by Sullivan and others,1 which has become one of the most frequently used models in the field and provided profound insights to many different aspects of A-type lamin function. Here, we report the unexpected finding that these mice express a truncated Lmna gene product on both transcriptional and protein level. Combining different approaches including mass spectrometry, we precisely define this product as a C-terminally truncated lamin A mutant that lacks domains important for protein interactions and post-translational processing. Based on our findings we discuss implications for the interpretation of previous studies using Lmna$$^{−/−}$$ mice and the concept of human laminopathies.
|
{"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": 0.1634758561849594, "perplexity": 3059.0825641770034}, "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-2020-24/segments/1590347409337.38/warc/CC-MAIN-20200530133926-20200530163926-00041.warc.gz"}
|
https://www.physicsforums.com/threads/tangential-speed.288466/
|
# Tangential speed
1. Jan 29, 2009
### gigglin_horse
1. The problem statement, all variables and given/known data
I thought this would be an easy question for me, but I cant figure it out.
"What is the tangential speed of a passenger on a Ferris wheel that has a radius of 10 meters and rotates once every 30 seconds?"
2. Relevant equations
Tangential speed = rotational speed x radial distance
3. The attempt at a solution
Tangential speed = 2RMP x 10 meters
= 20......what units? Not m/sec, not RPM.....
...But...
I figured the circumference is 62.83 meters x 2RPM = 125 meters per minute
2. Jan 29, 2009
### Hannisch
With the information that it's 2RPM, you can very easily find the angluar velocity, ω. I'd use that as a starting point to finding the tangential velocity.
3. Jan 29, 2009
### gigglin_horse
That doesn't help...
thanks though
Similar Discussions: Tangential speed
|
{"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": 0.9516362547874451, "perplexity": 3027.9910866169876}, "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-2017-17/segments/1492917120844.10/warc/CC-MAIN-20170423031200-00125-ip-10-145-167-34.ec2.internal.warc.gz"}
|
https://gmatclub.com/forum/if-5x-2-has-two-different-prime-factors-at-most-how-many-di-163209.html?sort_by_oldest=true
|
It is currently 20 Oct 2017, 20:24
### GMAT Club Daily Prep
#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized
for You
we will pick new questions that match your level based on your Timer History
Track
every week, we’ll send you an estimated GMAT score based on your performance
Practice
Pays
we will pick new questions that match your level based on your Timer History
# Events & Promotions
###### Events & Promotions in June
Open Detailed Calendar
# If 5x^2 has two different prime factors, at most how many di
Author Message
TAGS:
### Hide Tags
Intern
Joined: 25 Jan 2013
Posts: 2
Kudos [?]: 26 [4], given: 3
If 5x^2 has two different prime factors, at most how many di [#permalink]
### Show Tags
14 Nov 2013, 09:24
4
KUDOS
17
This post was
BOOKMARKED
00:00
Difficulty:
85% (hard)
Question Stats:
42% (00:54) correct 58% (00:45) wrong based on 366 sessions
### HideShow timer Statistics
If 5x^2 has two different prime factors, at most how many different prime factors does x have?
(A) 1
(B) 2
(C) 3
(D) 4
(E) 5
[Reveal] Spoiler: OA
Last edited by Bunuel on 14 Nov 2013, 09:26, edited 1 time in total.
Renamed the topic and edited the question.
Kudos [?]: 26 [4], given: 3
Math Expert
Joined: 02 Sep 2009
Posts: 41892
Kudos [?]: 129046 [3], given: 12187
Re: If 5x^2 has two different prime factors, at most how many di [#permalink]
### Show Tags
14 Nov 2013, 13:07
3
KUDOS
Expert's post
3
This post was
BOOKMARKED
suprememodelrus wrote:
If 5x^2 has two different prime factors, at most how many different prime factors does x have?
(A) 1
(B) 2
(C) 3
(D) 4
(E) 5
x cannot have more than 2 prime factors, because in this case 5x^2 would also have more than 2 prime factors.
Can x have 2 prime factors? Yes, consider x=2*5=10 (in this case 5x^2 still has 2 prime factors).
_________________
Kudos [?]: 129046 [3], given: 12187
Intern
Joined: 23 Aug 2013
Posts: 46
Kudos [?]: 11 [0], given: 8
Re: If 5x^2 has two different prime factors, at most how many di [#permalink]
### Show Tags
13 Feb 2014, 04:07
A little bit more explaination:
5x^2 has 2 prime factors.
One of them has to be 5 (since 5 is a factor of 5x^2 and 5 is prime).
Since the question asks for maximum no of prime factors that x can have, the answer has to be 2 (One of the two prime nos has to be 5, like x can be 10 or 15 or 20 ...etc, with 5 along with 2 0r 3 as the other prime factor)
The other factor is not known to us.
Moreover, since the question says 5x^2 has two different prime factors, x must have atleast one factor other than 5
Kudos [?]: 11 [0], given: 8
GMAT Club Legend
Joined: 09 Sep 2013
Posts: 16637
Kudos [?]: 273 [0], given: 0
Re: If 5x^2 has two different prime factors, at most how many di [#permalink]
### Show Tags
09 Mar 2015, 11:07
Hello from the GMAT Club BumpBot!
Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).
Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
Kudos [?]: 273 [0], given: 0
GMAT Club Legend
Joined: 09 Sep 2013
Posts: 16637
Kudos [?]: 273 [0], given: 0
Re: If 5x^2 has two different prime factors, at most how many di [#permalink]
### Show Tags
13 Oct 2016, 11:41
Hello from the GMAT Club BumpBot!
Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).
Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
Kudos [?]: 273 [0], given: 0
BSchool Forum Moderator
Joined: 12 Aug 2015
Posts: 2212
Kudos [?]: 841 [0], given: 595
Re: If 5x^2 has two different prime factors, at most how many di [#permalink]
### Show Tags
14 Jan 2017, 01:14
Properties in action->
1->When we multiply a positive integer x with another positive integer n,the number of prime factors of nx may be equal to x or greater than x.
2->$$X$$ and $$X^n$$ always have the exact same prime factors.
Case 1
In this case since 5x^2 has 2 prime factors.
So x can have one prime factors => and that will not be 5 so that 5x^2 has two primes.
OR
Case 2
In this case x can have two prime factors including 5 => e.g => x=5*3 => 5x^2=> 2 prime factors.
Hence At the most -> x can have 2 prime factors.
Hence B.
_________________
Give me a hell yeah ...!!!!!
Kudos [?]: 841 [0], given: 595
Re: If 5x^2 has two different prime factors, at most how many di [#permalink] 14 Jan 2017, 01:14
Display posts from previous: Sort by
# If 5x^2 has two different prime factors, at most how many di
Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.
|
{"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": 0.2570648789405823, "perplexity": 4817.687988776044}, "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-2017-43/segments/1508187824543.20/warc/CC-MAIN-20171021024136-20171021044136-00144.warc.gz"}
|
http://math.stackexchange.com/questions/74676/axiom-of-choice-non-measurable-sets-countable-unions
|
# Axiom of choice, non-measurable sets, countable unions
I have been looking through several mathoverflow posts, especially these ones http://mathoverflow.net/questions/32720/non-borel-sets-without-axiom-of-choice , http://mathoverflow.net/questions/73902/axiom-of-choice-and-non-measurable-set and there still are many questions I would like to ask:
1) According to the first answer of the first post "It is consistent with ZF without choice that the reals are the countable union of countable sets" (and therefore all sets are borel, and hence measurable), however this seems in contrast with the answer to the second post which states that "the existence of a non-Lebesgue measurable set does not imply the axiom of choice" (and therefore it is possible to construct a ZF model without choice where there exists a non-Lebesgue-measurable set). How can these two statements be both right?
2) I can't understand why the axiom of (countable) choice is necessary to prove that a countable union of countable sets is countable. By saying that the sets are countable, I have already assumed the existence of a bijection from every set to the set of natural numbers, in other words, I have indexed the elements of each set. So what is the problem in chosing elements from each set? This relates to the above topic in that if the AC weren't necessary to prove that countable union of countable sets is countable, then "It is consistent with ZF without choice that the reals are the countable union of countable sets" can no longer be correct, since this would imply that in ZF without choice the reals are countable.
I am only a third year math student with no background in set theory (only naive), so please excuse the ignorance. I hope someone can answer me, thank you!
-
I'm glad to see your question worked out and you got some wonderful answers here. For this kind of question, math.SE is better suited than MO. – Arturo Magidin Oct 21 '11 at 23:15
Yes, and thank you for redirecting me! I suspect I will be using this website a lot in the future... – Emilio Ferrucci Oct 22 '11 at 8:48
For the first question, let us consider the following statement:
$x\in\mathbb R$ and $x\ge 0$. It is consistent with this statement that:
1. $x=0$,
2. $x=1$,
3. $x>4301$,
4. $x\in (2345235,45237911+\frac{1}{2345235})$
This list can go on indefinitely. Of course if $x=0$ then none of the other options are possible. However if we say that $x>4301$ then the fourth option is still possible.
The same is here. If all sets are measurable then it contradicts the axiom of choice; however the fact that some set is unmeasurable does not imply the axiom of choice since it is possible to contradict the axiom of choice in other ways. It is perfectly possible that the universe of set theory behave "as if it has the axiom of choice" up to some rank which is so much beyond the real numbers that everything you can think of about real numbers is as though the axiom of choice holds; however in the large universe itself there are sets which you cannot well order. Things do not end after the continuum.
That been said, of course the two statements "$\mathbb R$ is countable union of countable sets and "There are non-measurable sets" are incompatible. However this is the meaning of it is consistent relatively to ZF. It means that each of those can exist with the rest of the axioms of ZF without adding contradictions (as we do not know that ZF itself is contradiction-free to begin with.)
As for the second question, of course each set is countable and thus has a bijection with $\mathbb N$. From this the union of finitely many countable sets is also countable.
However in order to say that the union of countably many countable sets is countable one must fix a bijection of each set with $\mathbb N$. This is exactly where the axiom of choice comes into play.
There are models in which a countable union of pairs is not only not countable, but in fact has no countable subset whatsoever!
Assuming the axiom of countable choice we can do the following:
Let $\{A_i\mid i\in\mathbb N\}$ be a countable family of disjoint countable sets. For each $i$ let $F_i$ be the set of injections of $A_i$ into $\mathbb N$. Since we can choose from a countable family, let $f_i\in F_i$.
Now define $f\colon\bigcup A_i\to\mathbb N\times\mathbb N$ defined by: $f(a)= f_i(a)$, this is well defined as there is a unique $i$ such that $a\in A_i$. From Cantor's pairing function we know that $\mathbb N\times\mathbb N$ is countable, and so we are done.
-
So the axiom of choice is necessary to choose a bijection from each set to N. I might be able to prove particular cases without using the AC (by defining the bijections explicitly), but in general I have no such guarantee, correct? And do I need the axiom of choice to prove that a countable union of finite sets is countable (for the same reason)? Where can I find a proof that in ZF without choice the set of real numbers is a countable union of countable sets? (perhaps a well known text book which I can find in my university library). Thank you very much for your answer! – Emilio Ferrucci Oct 21 '11 at 21:41
@Emilio: Yes, it is necessary to fix a bijection. However in some cases you can have the bijection defined explicitly. For example $\bigcup\{n\}\times\mathbb N$ is of course countable. As for finite sets the situation is similar, although you could reduce the axiom of countable choice slightly (choose from finite sets), but as the example I have mentioned (union of pairs) shows this is still not provable. Lastly, the proof is not from ZF, but rather that it is possible to have this. The proof is not very accessible without some extensive preliminaries in set theory such as forcing. – Asaf Karagila Oct 21 '11 at 21:47
Ok things are definetly clearer now. Looks like it's back to measure theory for me! Thanks again for everyone's answers – Emilio Ferrucci Oct 21 '11 at 21:53
@Emilio: No problem. You should thank the other answerers in comments on their own answers though. :-) – Asaf Karagila Oct 21 '11 at 22:00
For Question $1$, the assertion "the existence of a non-Lebesgue measurable set does not imply the axiom of choice" means that we cannot prove the full Axiom of Choice from the existence of a non-Lebesgue measurable set. Similarly, we cannot prove the full Axiom of Choice from the assumption of Countable Choice. But we cannot prove Countable Choice in ZF (here I should insert "if ZF is consistent," but won't bother).
There are many assertions that cannot be proved in ZF, can be proved in ZFC, but do not imply the full Axiom of Choice, that is, are strictly weaker than the full Axiom of Choice. The existence of a non-Lebesgue measurable set is just one of them. So you can think of an axiom that asserts the existence of a non-measurable set as intermediate in strength between making no "choice" assumptions at all, and asserting the full Axiom of choice.
Added: The following Wikipedia aricle has a nice list of assertions that are equivalent to the Axiom of Choice, and also a nice list of assertions that cannot be proved in ZF, can be proved in ZFC, but do not imply the Axiom of Choice.
-
(1) The statement
It is consistent with ZF without choice that the reals are the countable union of countable sets
does not mean that in ZF without choice, all subsets of $\mathbb R$ must be measurable. It just says that in that case, "all sets are measurable" is one possibility, possibly among many. Therefore it does not conflict with
the existence of a non-Lebesgue measurable set does not imply the axiom of choice
Taken together, these two statements just means that in ZF without choice there can either be nonmeasurable sets, or not be any nonmeasurable sets. Both possibilities are consistent.
(2) If you have a countable family of countable sets, all you know that for each set in the family there exist one or more bijections between that set and the natural numbers. As long as you're only looking at one of them, you can just choose one of these bijections. However, if you want to prove that the union of the family is countable, you need to choose a particular bijection for each of the sets simultaneously, and you need (countable) choice to do that.
-
The following sci.math post by Abhijit Dasgupta deals with something I had read, which claimed that every subset of $\mathbb R$ is $F_{\sigma \delta \sigma}$ in the Feferman-Levy model: groups.google.com/group/sci.math/msg/1c76fa715eda2302 – Dave L. Renfro Oct 21 '11 at 21:49
Perhaps so, but that is not the only model of ZF$\neg$C. (It cannot be; thanks to Gödel and Rosser every consistent extension of ZF will have an infinity of essentially different models). – Henning Makholm Oct 21 '11 at 21:56
|
{"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": 0.9711588621139526, "perplexity": 170.66879151254147}, "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/1398223211700.16/warc/CC-MAIN-20140423032011-00642-ip-10-147-4-33.ec2.internal.warc.gz"}
|
https://indico.cern.ch/event/357738/contributions/848768/
|
# TWEPP 2015 - Topical Workshop on Electronics for Particle Physics
28 September 2015 to 2 October 2015
Lisbon
Europe/Zurich timezone
## NaNet-10: a 10GbE Network Interface Card for the GPU-based Low-Level Trigger of the NA62 RICH Detector.
30 Sep 2015, 17:21
1m
Hall of Civil Engineering (Lisbon)
### Hall of Civil Engineering
#### Lisbon
IST (Instituto Superior Técnico ) Alameda Campus Av. Rovisco Pais, 1 1049-001 Lisboa Portugal
Poster Trigger
### Speaker
Andrea Biagioni (INFN)
### Description
A GPU-based low level (L0) trigger is currently integrated in the experimental setup of the RICH detector of the NA62 experiment to assess the feasibility of building more refined physics-related trigger primitives and thus improve the trigger discriminating power. To ensure the real-time operation of the system, a dedicated data transport mechanism has been implemented: an FPGA-based Network Interface Card (NaNet-10) receives data from detectors and forwards them with low, predictable latency to the memory of the GPU performing the trigger algorithms. Results of the ring-shaped hit patterns reconstruction will be reported and discussed.
### Summary
The NA62 particle physics experiment at CERN SPS aims at measuring the ultra rare kaon decay $K^{+} \rightarrow \pi^{+} \nu\overline{\nu}$ as a highly sensitive test of the Standard Model and a search for New Physics.
A multi-level trigger is designed to manage the high rate required by the experiment.
The lowest level (L0) trigger represents an essential element because it must handle an input event rate of the order of 10 MHz and apply a rejection factor of 10, with a maximum latency of 1 ms.
In the standard implementation of the L0 trigger, data contributing to the realization of the final trigger decision are computed on FPGA devices, and are mostly based on event multiplicity and topology.
The approach presented here aims at exploiting the parallel computing power of a commercial GPU (Graphics Processing Unit) to perform real-time software-based computations in the L0 trigger for the NA62 experiment.
The use of a GPU in this level would allow for building of more refined physics-related trigger primitives, such as energy or direction of the final state particles in the detectors, therefore leading to a net improvement of trigger conditions and data handling.
GPU architectures have been designed to optimize computing throughput with no particular attention to their usage in real-time contexts, such as the one we are considering here.
While execution times are rather stable on these architectures, also data transfer tasks are to be taken into account: assessment of the real-time features of the whole system needs a careful characterization of all subsystems along data stream path, from detectors to GPU memories.
We identified the standard network subsystem as the main source of fluctuations for the total system latency. To address this problem, we designed and implemented two generations of FPGA-based Network Interface Cards, NaNet-1 and NaNet-10, supporting respectively 1GbE and 10GbE I/O channels.
To achieve a low and stable communication latency, NaNet design combines support for GPUDirect, i.e. the direct data transport between the GPU memory and the external I/O channels, with a network protocol offloading module implemented in the FPGA logic.
A GPU-based L0 trigger using NaNet is currently integrated in the experimental setup of the RICH Cherenkov detector of the NA62 experiment in order to reconstruct the ring-shaped hit patterns, and results obtained with this system will be reported and discussed.
This work is included in a broader project concerning the use of GPUs for advanced scientific computation in real-time applications, named GAP (GPU Application Project).
### Primary authors
Alessandro Lonardo (Universita e INFN, Roma I (IT)) Andrea Biagioni (INFN) Francesca Lo Cicero (INFN Sezione di Roma) Gianluca Lamanna (Istituto Nazionale Fisica Nucleare Frascati (IT)) Luca Pontisso (Universita di Pisa & INFN (IT)) Marco Sozzi (Universita di Pisa & INFN (IT)) Michele Martinelli (INFN) Ottorino Frezza (INFN Sezione di Roma) Piero Vicini (INFN Rome Section) Roberto Ammendola (INFN)
### Co-authors
Davide Rossetti (Universita e INFN, Roma I (IT)) Elena Pastorelli (INFN Sezione di Roma) Ilaria Neri (Universita di Ferrara (IT)) Laura Tosoratto (INFN) Massimiliano Fiorini (Universita di Ferrara (IT)) Pier Stanislao Paolucci (INFN Sezione di Roma) Simula Francesco (INFN Sezione di Roma)
|
{"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": 0.5177679061889648, "perplexity": 7736.112585071814}, "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/1593655897844.44/warc/CC-MAIN-20200709002952-20200709032952-00093.warc.gz"}
|
http://www.mapleprimes.com/users/Hidious/questions
|
# Hidious
2 years, 68 days
These are questions asked by Hidious
### Maple objects display precedence in graph? ...
April 17 2011 by Maple 14
Hello all,
This is my first time posting here; I usually find answers to all my questions by searching patiently but I was unsuccessful with this particular issue.
I attend an introduction Maple class and i'm building an animated bike as project. I was already rather comfortable with Maple so i'm trying to show off a little by adding lots of cheesy details to the scene, even if unnecessary. However, some objects such as the sky, which i would like to...
Page 1 of 1
|
{"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": 0.9354310631752014, "perplexity": 1820.1549490754774}, "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-2013-20/segments/1368706934574/warc/CC-MAIN-20130516122214-00007-ip-10-60-113-184.ec2.internal.warc.gz"}
|
https://socratic.org/questions/how-many-molecules-are-in-1-09-moles-of-silicon-dioxide
|
Chemistry
Topics
# How many molecules are in 1.09 moles of silicon dioxide?
$1.09 \times {N}_{A}$, where ${N}_{A} = \text{Avogadro's Number}$
|
{"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 2, "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": 0.9474790096282959, "perplexity": 6046.950252481525}, "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/1590348511950.89/warc/CC-MAIN-20200606062649-20200606092649-00244.warc.gz"}
|
https://www.physicsforums.com/threads/ball-projectile-physics.66369/
|
# Ball projectile physics
1. Mar 7, 2005
### carltonblues
1)A ball is thrown upward with an initial velocity of v = 20 m/s. How long is the ball in the air? What is the greatest height of the ball? When is the ball 15 m
above the ground?
1) I have figured out
t total = 4.08s
greatest height = 20.4m
For the last bit (Finding the time when x=15m), I am having trouble. I know the answer but cannot work it through.
Do I use s = ut+1/2at^2 for it?
If I do, it wont work out because the 20.4 m has to come into it, doesnt it?
Please help!
2. Mar 7, 2005
### dextercioby
The equation giving height (let's label it through 'y') as function of time is
$$y(t)=v_{0}t-\frac{1}{2}gt^{2}$$
Now set "y" to 15m and solve for "t"...
Daniel.
3. Mar 7, 2005
Cheers mate
4. Mar 9, 2005
### Am kuls
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook
Have something to add?
Similar Discussions: Ball projectile physics
|
{"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7729048132896423, "perplexity": 3903.1338881057623}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-50/segments/1480698541396.20/warc/CC-MAIN-20161202170901-00358-ip-10-31-129-80.ec2.internal.warc.gz"}
|
http://physics.stackexchange.com/questions/61510/solve-the-angular-part-of-schrodinger-equation-numerically
|
# Solve the angular part of Schrodinger equation numerically
I would like to solve the angular part (the one for what is usually called the $\theta$ angle) of a time-independent 3D Schrodinger equation $$\frac{\mathrm{d}}{\mathrm{d}x}\left[ (1-x^2) \frac{\mathrm{d}P(x)}{\mathrm{d}x} \right]+\left[ l(l+1) - \frac{m^2}{1-x^2} \right]P(x) = 0,$$ where $l=0,1,2,\ldots$ and $m = -l, -l+1, \ldots, l$ as usual and $x\in[-1,1]$,
Now, the complication is that I want to do it numerically. Analytically, one gets a bunch of Legendre polynomials and spherical harmonics. However, for me it is unclear which boundary conditions should I set.
One boundary condition will probably be equivalent to the normalization of my solutions. In order to make it compatible with the Legendre polynomials, I can set it to $$P(1) =1.$$
However, what about the second one (it is a second-order ODE after all)? I guess, it should somehow encode the fact that my solutions should be bounded.
Any comments, including sending me to RTFM (with appropriate links) are more than welcome!
-
The other solutions are associated Legendre functions of the second kind, which blow up at $x=\pm 1$. – Michael Brown Apr 18 '13 at 14:31
In order to help you, it would be good to know which method you are using to solve this numerically. Maybe this question would be better placed in Computational Science SE. – lomppi Apr 18 '13 at 15:23
Michael Brown: I would consider these solutions unphysical and avoid them. Also, they are excluded by the P(1)=1 condition. sebastian: at this moment I am trying to formulate the problem, because it is not possible to feed it to any algorithm (method) as it is. Therefore, in my opinion, this is a Physics question and not a CS one. – ffc Apr 18 '13 at 16:02
ok, but you should at least give a clue whether you want to take a finite difference approach or something else. otherwise it will be difficult to help you. I did some googeling and found this link. maybe it helps. – lomppi Apr 18 '13 at 17:30
What physical problem are you trying to solve - free particle? hydrogen atom? spherical infinite well? spherical annular well? Boundary conditions depend on the problem, not the ODE. – Chris White Apr 19 '13 at 1:41
What you are doing is an eigenvalue problem. Eigenvectors are determined by the space you are looking at, and this is why you usually specify some boundary conditions. In your case just the requirement of absence of singularities should do the job (i.e. you want some subspace of $C[-1,1]$). This is the analytical viewpoint.
The numerical viewpoint actually depends on your algorithm. First of all, if you really want "to solve the equation numerically", I assume that you are playing the game of not knowing the answer. So you do not actually know that $l$ is integer beforehand. If I were solving the problem, I would put it on a lattice and then write it as a finite-dimensional eigenvalue problem. In deriving the finite difference equations I would use the fact that my solution should be finite at the endpoints of the interval.
A way to do this is to introduce homogenious lattice at points (lets call them so) 0,1,2,3,4... Then integrate the equation from $i-1/2$ to $i+1/2$ and use middle-difference fromulae for derivatives (you will need their values at $i\pm1/2$, so the middle difference will return you back to your lattice) and middle-rectangles formula for integrals (it is important to use approximations of the proper order. I believe that I am telling you an algorithm of second-order presicion). Then you will have to do something with the endpoints. For them do the integration from $0$ to $1/2$ and respectively on the other end. In doing so you will use the fact that $(1-x^2)\frac{dP}{dx}$ is $0$ at the endpoints. And this picks up the appropriate space for your solutions.
Long story made short, I believe that at least for some calculational schemes the conditions should be that $(1-x^2)\frac{dP}{dx}$ vanishes at the endpoints.
-
This is a good answer, so I will accept it - thank you! However, I have found out that it is possible to circumvent the problem (which is somewhat equivalent to Peter's answer) by writing the equation in the original form, namely $$\frac{1}{\sin (\theta)} \frac{d}{d\theta} \sin \theta \frac{d}{d\theta} f(\theta) = b \theta,$$ where $f$ is the function to be found and the boundary conditions are $f'(\pi) = 0$ and normalization $f(\pi)=1$. Then the eigenvalue $b$ is such that the derivative at the left-hand side also vanishes: $f'(0)=0$. – ffc May 6 '13 at 9:08
It should have been $$\frac{1}{\sin (\theta)} \frac{d}{d\theta} \sin \theta \frac{d}{d\theta} f(\theta) = b f(\theta)$$ in the previous comment, and I wrote up just the $m=0$ case. – ffc May 6 '13 at 9:14
Since the coordinate is an angle, you should specify the periodic boundary conditions.
-
|
{"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8944565653800964, "perplexity": 262.70116640056614}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-32/segments/1438042988840.31/warc/CC-MAIN-20150728002308-00004-ip-10-236-191-2.ec2.internal.warc.gz"}
|
https://brilliant.org/problems/advance-happy-new-year-2015-3/
|
# Egyptian Fraction with New Years 2015
How many ordered pairs of positive integers $$(x,y)$$ are there such that
$\frac{ 1}{x} + \frac{ 1}{y} = \frac{1}{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": 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": 0.28394046425819397, "perplexity": 601.8068022539118}, "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-2017-04/segments/1484560279410.32/warc/CC-MAIN-20170116095119-00569-ip-10-171-10-70.ec2.internal.warc.gz"}
|
https://papers-gamma.link/Maximimi/page/10
|
### Comments:
Overall a very nice paper. Given a small set of query nodes, how can we find its community (a "compact" connected subgraph strongly related to the query nodes)? An optimization is formalized and an efficient optimal algorithm (inspired by the k-core decomposition) to solve the optimization is devised. Efficient heuristics are also suggested. The following points could be improved. ### Not clear examples of monotone functions: - "Example 2 (Minimum degree) Let $f_m(G)$ be the minimum degree of any node in $G$. The function $f_m$ is monotone.". That is not true: when removing nodes from a given graph, the minimum degree can increase and then decrease. - "Example 3 (Distance) The functions $D_Q(G, v)$ and $D_Q(G)$, defined by Equations (1) and (2) are node-monotone and monotone, respectively." That is not true: "$D_Q(G)$" is not monotone: it can decrease and increase when removing nodes. In addition, with this definitions the query nodes should not be removed, this is not specified. - "A lower bound on the number of nodes in a graph is monotone". This is not clear. I think that what is meant is not that any function that is a lower bound on the number of nodes (e.g., $f(V)=|V|/2$) is monotone, but that requiring a lower bound on the number of nodes is monotone. - "$M_Q(G)=\max_{v\in V(G)}\{M_Q(G,v)\}$ is monotone". That is not true. - "The number of disjoint paths between two nodes (which is a popular measure for friendship strength) is node-monotone non-increasing." This is not clear, the function should of the form $f_m(G,v)$, is $v$ one of the two nodes? - "with a monotone function (such as maximum distance and minimum degree).". It is not clear what "maximum distance" means. If it means "the diameter of the graph", then this function is not monotone as it can increase or decrease when removing nodes. - Note that only node-monotone functions are of interest for the suggested method and monotone functions are not used. "Problem 3 (Cocktail party) We are given an undirected graph $G=(V, E)$, a node-monotone non-increasing function $f$, as well as a set of monotone non-increasing properties $f_1,...,f_k$. We seek to find an induced subgraph $H$ of $G$ that maximizes $f$ among all induced subgraphs of $G$ and satisfies $f_1,...,f_k$. A similar problem can be defined by considering to minimize monotone non-decreasing functions.". In that problem "monotone" should be replaced by "node-monotone". ### Experiments: - "We implemented our algorithms in Perl and all experiments run on a dual-core Opteron processor at 3GHz." The implementation does not seem to be publicly available. - I think that more informations on how to reconstruct the graphs on which the experiments are run could be given. Some of the datasets do not seem to be publically available. - In Table 1, I think that the first line is about the distance constraint. The number of query nodes and how they are picked does not seem to be specified. - As the experiments in Table 1, Figure 1 and Figure 2 are the results of an average, error bars could be given to see how significant the differences are. ### Implementation details and asymptotic complexity: - An asymptotic time complexity is not given. - Implementation details are lacking. In particular, it is not clear how to check that the query nodes are connected at each step. This does not seem to be so trivial. If a BFS has to be run everytime a node is deleted, then the algorithm would be in $\Omega(n^2)$ and might be too slow for large graphs. ### Comparison against connectivity subgraph (reference [10], [28] and [21]): "Faloutsos et al. [10], Tong et al. [28], as well as other researchers have studied the problem of finding a subgraph that connects a set of query nodes in a graph. The main difference of our approach is that we are not just interested in connecting the query nodes, but also in finding a meaningful community of query nodes." To me "community search" is similar to "connectivity subgraph": if the upper bound on the number of nodes is small enough then indeed "connectivity subgraph" can be seen as "just connecting the query nodes". However, if this upper bound $k$ is higher, then the goal of "connectivity subgraph" is to find $k$ nodes connecting the query nodes and relevant to it, which is similar to the goal of "community search". I think that a comparison to the "connectivity subgraph" line of work can be carried. At least for the "case study" on the communities of Papadimitriou in DBLP. ### Node-monotone functions: Maybe defining a node-monotone function as a function $f(G,U,v)$ of the input graph $G=(V,E)$, a set of vertices $U\subset V$ and a node $v\in U$ is interesting. This would allow taking the outside of the induced subgraph on $U$ into account. As an example: the number of neighbors $v$ has in $U$ is node-monotone non-increasing, but the number of neighbors $v$ has in $V\setminus U$ is node-monotone non-decreasing (this second function is hard to express with the definition of node-monotone function given in the paper). ### Typos: - "Graphs is one of most ubiquitous data representations" ->? "Graphs are one of the most ubiquitous data representations" - "there is need for" ->? "there is a need for" - "It has been one of them most well-studied problems" -> "one of the most" - "Brunch and bound" :) -> "Branch and bound" - "in order to extracting informations" -> "in order to extract informations" - "divided by all possible possible edges" - "that are far way from" ->? "far away from" - "We start by present an optimal algorithm" - "$G_{T−1}$": "T" -> "t". - "we still assume that $d=|V|$" -> "$d=|V|^3$" - "Now are are ready" - "The dist ance" - ", which we denote be $q=|Q|$" - "for the the heuristic" - "This reason is that" -> "The reason is that" - "with our heuristics This is shown in": "." lacking. - " we think that it is quite remarkable that GreedyDist finds subgraph average distance more than 5" -> "finds a subgraph of average degree more than 5", and not "distance". - "we can see from indeed" - "it belongs in" ->? "it belongs to" - "The aim is to find compact a community" ->? "The aim is to find a compact community" - "the situation is not so agreeable" ->? "the situation is not so pleasant" - "and it is densely connected" ->? "and is densely connected"
Read the paper, add your comments…
### Comments:
Read the paper, add your comments…
### Comments:
### Very nice associated website: http://web.stanford.edu/~montanar/SDPgraph/ Slides: http://www.lps.ens.fr/~krzakala/LESHOUCHES2017/talks/LesHouches2017_RicciTersenghi.pdf ### Generalising to the Goemans-Williamson algorithm: Can we implement the Goemans-Williamson algorithm using this "spin technique"? This is a try: https://github.com/maxdan94/spingraphSDP I think that it may be interesting as it could lead to a scalable implementation of the Goemans-Williamson algorithm. ### Minors: - In the main text, some equation numbers correspond to the equations in the supplementary material, e.g. "(42)", "(49)" or "(288)". This makes the paper hard to read. "(288)" should be replaced by "(10)". - "solving the combinatorial optimization problem in Eq. (5) is a prototypical NP-complete problem." This is not a decision problem and thus it cannot be NP-complete by definition. - "(total CPU time was about 10 years)" This is not clear: what does it mean exactly? Which type of machines were used?
### Wrong reference: I read "It is also known that, for $m >\sqrt{2 n}$, the problem (49) has no local optima except the global ones [BM03]." In [BM03], which is [this paper](https://papers-gamma.link/paper/55), there is no such proof! We can only read: "Theorem 2.2. There exists an optimal solution $X^∗$ of (1) with rank r satisfying the inequality $r(r+ 1)/2 ≤ m$." and "we present computational results which show that the method finds optimal solutions to (2) quite reliably, and although we are able to derive some amount of theoretical justification for this, our belief that the method is not strongly affected by the inherent nonconvexity of (2) is largely experimental" but not that any local minimum is a global minimum.
> ### Minors: > > - "(total CPU time was about 10 years)" This is not clear: what does it mean exactly? Which type of machines were used? Although the algorithm based on the minimization of a non-convex cost function in terms of m-component variables is extremely fast to solve a single SBM problem (see e.g. figure 5 in https://arxiv.org/pdf/1603.09045, where many numerical experiments are reported) the precise determination of the critical threshold in the sparse case (i.e. SBM) required a large numerical effort of more than 80,000 core hours (we run all out simulations on Intel(R) Xeon(R) CPU E5-2670 @ 2.60GHz).
Read the paper, add your comments…
|
{"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": 0.7593564391136169, "perplexity": 764.734484346599}, "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-2019-22/segments/1558232257361.12/warc/CC-MAIN-20190523184048-20190523210048-00085.warc.gz"}
|
http://soscholar.com/domain/detail?domain_id=b0f4acd3-0f99-d49b-c837-30c817eeb0c4
|
Differential Algebra 152 浏览 0关注
In mathematics, differential rings, differential fields, and differential algebras are ring (mathematics)|rings, field (mathematics)|fields, and algebra over a field|algebras equipped with a derivation (abstract algebra)|derivation, which is a Unary operation|unary function that is linear and satisfies the Product rule|Leibniz product rule. A natural example of a differential field is the field of rational functions C(t) in one variable, over the complex numbers, where the derivation is differentiation with respect to t.
相关概念
主要的会议/期刊 CDC ISSAC PAC BIT CORR AAECC NA JSC
|
{"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": 0.9293864965438843, "perplexity": 3556.6371418693398}, "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/1516084890795.64/warc/CC-MAIN-20180121155718-20180121175718-00763.warc.gz"}
|
https://amsi.org.au/ESA_Senior_Years/SeniorTopic1/1c/1c_4history_2.html
|
## History and applications
### History
The expansion $$(a+b)^2 = a^2+2ab+b^2$$ appears in Book 2 of Euclid. There it is stated in geometric terms:
If a line segment is cut at random, the square on the whole is equal to the square on each of the line segments which have been formed and twice the rectangle which has these line segments as length and width.
The triangle of numbers that we refer to as Pascal's triangle was known before Pascal. Pascal developed many uses of it and was the first one to organise all the information together in his 1653 treatise.
The triangle had been discovered centuries earlier in India and China. In the 13th century, Yang Hui (1238–1298) knew of this triangle of numbers. In China, Pascal's triangle is called Yang Hui's triangle. The triangle was known in China in the early 11th century by the mathematician Jia Xian (1010–1070). It was also discussed by the Persian poet-astronomer-mathematician Omar Khayyam (1048–1131). In Iran, the triangle is referred to as the Khayyam–Pascal triangle or simply the Khayyam triangle. Several theorems related to the triangle were known, including the binomial theorem for non-negative integer exponents. In Europe, it first appeared as the frontispiece of a book by Petrus Apianus (1495–1552) and this is the first printed record of the triangle in Europe. In Italy, it is still referred to as Tartaglia's triangle, named for the Italian algebraist Niccolo Tartaglia (1500–1577).
Although Pascal was not the first to study this triangle, his work on the topic was the most important. Pascal's work on the binomial coefficients led to Newton's discovery of the general binomial theorem for fractional and negative powers.
Next page - Answers to exercises
|
{"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": 0.7721551060676575, "perplexity": 900.0137752037894}, "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-2022-40/segments/1664030336921.76/warc/CC-MAIN-20221001195125-20221001225125-00320.warc.gz"}
|
https://searxiv.org/search?author=Peng%20Sun
|
### Results for "Peng Sun"
total 16554took 0.12s
On the Entropy of Flows with Reparametrized Gluing Orbit PropertySep 27 2018We show that a flow or a semiflow with a weaker reparametrized form of gluing orbit property is either minimal or of positive topological entropy.
Ergodic properties of N-continued fractionsApr 26 2017Apr 29 2018We discuss some ergodic properties of the generalized Gauss transformation $$T_N(x)=\{\frac{N}{x}\}.$$ We generalize a series of results for the regular continued fractions, such as Khinchin's constant and L\'evy's constant.
A Generalization of Gauss-Kuzmin-Lévy TheoremMay 08 2017Nov 09 2017We prove a generalized Gauss-Kuzmin-L\'evy theorem for the $p$-numerated generalized Gauss transformation $$T_p(x)=\{\frac{p}{x}\}.$$ In addition, we give an estimate for the constant that appears in the theorem.
A Generalization of the Gauss-Kuzmin-Wirsing constantJun 14 2017We generalize the result of Wirsing on Gauss transformation to the generalized tranformation $T_p(x)=\{\cfrac{p}{x}\}$ for any positive integer $p$. We give an estimate for the generalized Gauss-Kuzmin-Wirsing constant.
Zero-Entropy Dynamical Systems with Gluing Orbit PropertyOct 21 2018We show that a dynamical system with gluing orbit property and zero topological entropy is equicontinuous, hence it is topologically conjugate to a minimal rotation.
Measures of Intermediate Entropies for Skew Product DiffeomorphismsJun 10 2009Jan 18 2010In this paper we study a skew product map $F$ with a measure $\mu$ of positive entropy. We show that if on the fibers the map are $C^{1+\alpha}$ diffeomorphisms with nonzero Lyapunov exponents, then $F$ has ergodic measures of intermediate entropies. ... More
Exponential Decay of Expansive ConstantsJan 04 2011A map $f$ on a compact metric space is expansive if and only if $f^n$ is expansive. We study the exponential rate of decay of the expansive constant of $f^n$. A major result is that this rate times box dimension bounds topological entropy.
Zero-Entropy Dynamical Systems with Gluing Orbit PropertyOct 21 2018Apr 06 2019We show that a dynamical system with gluing orbit property and zero topological entropy is equicontinuous, hence it is topologically conjugate to a minimal rotation. Moreover, we show that a dynamical system with gluing orbit property has zero topological ... More
Minimality and Gluing Orbit PropertyAug 02 2018Aug 21 2018We show that a topological dynamical system is either minimal or have positive topological entropy. Moreover, for equicontinuous systems, we show that topological transitivity, minimality and orbit gluing property are equivalent. These facts reflect the ... More
Exponential Decay of Lebesgue NumbersFeb 02 2010Nov 20 2010We study the exponential rate of decay of Lebesgue numbers of open covers in topological dynamical systems. We show that topological entropy is bounded by this rate multiplied by dimension. Some corollaries and examples are discussed.
Energy Evolution for the Sivers Asymmetries in Hard ProcessesApr 18 2013Aug 12 2013We investigate the energy evolution of the azimuthal spin asymmetries in semi-inclusive hadron production in deep inelastic scattering (SIDIS) and Drell-Yan lepton pair production in pp collisions. The scale dependence is evaluated by applying an approximate ... More
On the unsplittable minimal zero-sum sequences over finite cyclic groups of prime orderSep 06 2014Let $p > 155$ be a prime and let $G$ be a cyclic group of order $p$. Let $S$ be a minimal zero-sum sequence with elements over $G$, i.e., the sum of elements in $S$ is zero, but no proper nontrivial subsequence of $S$ has sum zero. We call $S$ is unsplittable, ... More
TMD Evolution: Matching SIDIS to Drell-Yan and W/Z Boson ProductionAug 22 2013We examine the QCD evolution for the transverse momentum dependent observables in hard processes of semi-inclusive hadron production in deep inelastic scattering and Drell-Yan lepton pair production in $pp$ collisions, including the spin-average cross ... More
Decentralized Detection with Robust Information Privacy ProtectionAug 30 2018Feb 14 2019We consider a decentralized detection network whose aim is to infer a public hypothesis of interest. However, the raw sensor observations also allow the fusion center to infer private hypotheses that we wish to protect. We consider the case where there ... More
On the Relationship Between Inference and Data Privacy in Decentralized IoT NetworksNov 26 2018In a decentralized Internet of Things (IoT) network, a fusion center receives information from multiple sensors to infer a public hypothesis of interest. To prevent the fusion center from abusing the sensor information, each sensor sanitizes its local ... More
On the Relationship Between Inference and Data Privacy in Decentralized IoT NetworksNov 26 2018Apr 01 2019In a decentralized Internet of Things (IoT) network, a fusion center receives information from multiple sensors to infer a public hypothesis of interest. To prevent the fusion center from abusing the sensor information, each sensor sanitizes its local ... More
On the Relationship Between Inference and Data Privacy in Decentralized IoT NetworksNov 26 2018Apr 07 2019In a decentralized Internet of Things (IoT) network, a fusion center receives information from multiple sensors to infer a public hypothesis of interest. To prevent the fusion center from abusing the sensor information, each sensor sanitizes its local ... More
Hydrodynamics with conserved current via AdS/CFT correspondence in the Maxwell-Gauss-Bonnet gravityMar 19 2011Jun 05 2011Using the AdS/CFT correspondence, we study the hydrodynamics with conserved current from the dual Maxwell-Gauss-Bonnet gravity. After constructing the perturbative solution to the first order based on the boosted black brane solution in the bulk Maxwell-Gauss-Bonnet ... More
Gluon Distribution Functions and Higgs Boson Production at Moderate Transverse MomentumSep 07 2011We investigate the gluon distribution functions and their contributions to the Higgs boson production in pp collisions in the transverse momentum dependent factorization formalism. In addition to the usual azimuthal symmetric transverse momentum dependent ... More
Soft Gluon Resummations in Dijet Azimuthal Angular Correlations at the ColliderMay 05 2014We derive all order soft gluon resummation in dijet azimuthal angular correlation in hadronic collisions at the next-to-leading logarithmic level. The relevant coefficients for the Sudakov resummation factor, the soft and hard factors, are calculated. ... More
The role of protection zone on species spreading governed by a reaction-diffusion model with strong Allee effectNov 30 2018It is known that a species dies out in the long run for small initial data if its evolution obeys a reaction of bistable nonlinearity. Such a phenomenon, which is termed as the strong Allee effect, is well supported by numerous evidence from ecosystems, ... More
Transverse Momentum Resummation for $s$-channel single top quark production at the LHCNov 04 2018Feb 15 2019We study the soft gluon radiation effects for the $s$-channel single top quark production at the LHC. By applying the transverse momentum dependent factorization formalism, the large logarithms about the small total transverse momentum ($q_\perp$) of ... More
AOSO-LogitBoost: Adaptive One-Vs-One LogitBoost for Multi-Class ProblemOct 18 2011Jul 04 2012This paper presents an improvement to model learning when using multi-class LogitBoost for classification. Motivated by the statistical view, LogitBoost can be seen as additive tree regression. Two important factors in this setting are: 1) coupled classifier ... More
Scheme dependence and Transverse Momentum Distribution interpretation of Collins-Soper-Sterman resummationMay 21 2015Following an earlier derivation by Catani-de Florian-Grazzini (2000) on the scheme dependence in the Collins-Soper-Sterman (CSS) resummation formalism in hard scattering processes, we investigate the scheme dependence of the Transverse Momentum Distributions ... More
NLO QCD Corrections to $B_c$-to-Charmonium Form FactorsMar 10 2011Apr 15 2012The $B_c(^1S_0)$ meson to S-wave Charmonia transition form factors are calculated in next-to-leading order(NLO) accuracy of Quantum Chromodynamics(QCD). Our results indicate that the higher order corrections to these form factors are remarkable, and hence ... More
Long Range Correlation in Higgs Boson Plus Two Jets Production at the LHCApr 30 2016We study Higgs boson plus two high energy jets production at the LHC in the kinematics where the two jets are well separated in rapidity. The partonic processes are dominated by the t-channel weak boson fusion (WBF) and gluon fusion (GF) contributions. ... More
Quantum Transport in Topological Semimetals under Magnetic Fields IIDec 25 2018We review our recent works on the quantum transport, mainly in topological semimetals and also in topological insulators, organized according to the strength of the magnetic field. At weak magnetic fields, we explain the negative magnetoresistance in ... More
Quantum Non-Magnetic state near Metal-Insulator Transition - a Possible Candidate of Spin Liquid StateDec 13 2008Oct 09 2009In this paper, based on the formulation of an O(3) non-linear sigma model, we study the two-dimensional Pi-flux Hubbard model at half-filling. A quantum non-magnetic insulator is explored near the metal-insulator transition that may be a possible candidate ... More
Double refraction and spin splitter in a normal-hexagonal semiconductor junctionNov 17 2017In analogy with light refraction at optical boundary, ballistic electrons also undergo refraction when propagate across a semiconductor junction. Establishing a negative refractive index in conventional optical materials is difficult, but the realization ... More
Partitioning Well-Clustered Graphs: Spectral Clustering Works!Nov 07 2014Jan 31 2017In this paper we study variants of the widely used spectral clustering that partitions a graph into k clusters by (1) embedding the vertices of a graph into a low-dimensional space using the bottom eigenvectors of the Laplacian matrix, and (2) grouping ... More
Quantum Transport in Topological Semimetals under Magnetic Fields (II)Dec 25 2018May 04 2019We review our recent works on the quantum transport, mainly in topological semimetals and also in topological insulators, organized according to the strength of the magnetic field. At weak magnetic fields, we explain the negative magnetoresistance in ... More
Kinematical correlations for Higgs boson plus High Pt Jet Production at Hadron CollidersSep 14 2014We investigate the effect of QCD resummation to kinematical correlations in the Higgs boson plus high transverse momentum (Pt) jet events produced at hadron colliders. We show that at the complete one-loop order, the Collins-Soper-Sterman resummation ... More
Deep Reinforcement Learning Based Mode Selection and Resource Management for Green Fog Radio Access NetworksSep 15 2018Fog radio access networks (F-RANs) are seen as potential architectures to support services of internet of things by leveraging edge caching and edge computing. However, current works studying resource management in F-RANs mainly consider a static system ... More
Two-qubit controlled-PHASE Rydberg blockade gate protocol for neutral atoms via off-resonant modulated driving within a single pulseDec 10 2018Neutral atom array serves as an ideal platform to study the quantum logic gates, where intense efforts have been devoted to enhance the two-qubit gate fidelity. We report our recent findings in constructing theoretically a different type of two-qubit ... More
Anomalous Spin Dynamics of Hubbard Model on Honeycomb LatticesNov 16 2009In this paper, the honeycomb Hubbard model in optical lattices is investigated using O(3) non-linear sigma model. A possible quantum non-magnetic insulator in a narrow parameter region is found near the metal-insulator transition. We study the corresponding ... More
Globally Tuned Cascade Pose Regression via Back Propagation with Application in 2D Face Pose Estimation and Heart Segmentation in 3D CT ImagesMar 30 2015Recently, a successful pose estimation algorithm, called Cascade Pose Regression (CPR), was proposed in the literature. Trained over Pose Index Feature, CPR is a regressor ensemble that is similar to Boosting. In this paper we show how CPR can be represented ... More
Speeding-up Age Estimation in Intelligent Demographics System via Network OptimizationMay 22 2018Age estimation is a difficult task which requires the automatic detection and interpretation of facial features. Recently, Convolutional Neural Networks (CNNs) have made remarkable improvement on learning age patterns from benchmark datasets. However, ... More
Transverse Momentum Resummation for Dijet Correlation in Hadronic CollisionsJun 19 2015We study the transverse momentum resummation for dijet correlation in hadron collisions based on the Collins-Soper-Sterman formalism. The complete one-loop calculations are carried out in the collinear factorization framework for the differential cross ... More
Heavy Quarkonium Production at Low Pt in NRQCD with Soft Gluon ResummationOct 12 2012Apr 16 2013We extend the non-relativistic QCD (NRQCD) prediction for the production of heavy quarkonium with low transverse momentum in hadronic collisions by taking into account effects from all order soft gluon resummation. Following the Collins-Soper-Sterman ... More
Towards Information Privacy for the Internet of ThingsNov 14 2016Jun 29 2017In an Internet of Things network, multiple sensors send information to a fusion center for it to infer a public hypothesis of interest. However, the same sensor information may be used by the fusion center to make inferences of a private nature that the ... More
CAPRL: Signal Recovery from Compressive Affine Phase Retrieval via LiftingSep 11 2018Sep 20 2018In this paper, we consider compressive/sparse affine phase retrieval proposed in [B. Gao B, Q. Sun, Y. Wang and Z. Xu, Adv. in Appl. Math., 93(2018), 121-141]. By the lift technique, and heuristic nuclear norm for convex relaxation of rank and $\ell$ ... More
Application of gradient descent algorithms based on geodesic distancesApr 05 2019In this paper, the Riemannian gradient algorithm and the natural gradient algorithm are applied to solve descent direction problems on the manifold of positive definite Hermitian matrices, where the geodesic distance is considered as the cost function. ... More
Testing Charmonium Production Mechanism via Polarized $J/ψ$ Pair Production at the LHCMar 05 2009Jun 13 2010At present the color-octet mechanism is still an important and debatable part in the non-relativistic QCD(NRQCD). We find in this work that the polarized double charmonium production at the LHC may pose a stringent test on the charmonium production mechanism. ... More
SCAN+rVV10: A promising van der Waals density functionalOct 19 2015Apr 01 2016The newly developed "strongly constrained and appropriately normed" (SCAN) meta-generalized-gradient approximation (meta-GGA) can generally improve over the non-empirical Perdew-Burke-Ernzerhof (PBE) GGA not only for strong chemical bonding, but also ... More
Zero entropy invariant measures for some skew product diffeomorphismsDec 15 2008In this paper we study some skew product diffeomorphisms with nonuniformly hyperbolic structure along fibers. We show that there is an invariant measure with zero entropy which has atomic conditional measures along fibers.
Entropy and Ergodic Measures for Toral AutomorphismsMar 06 2011We show that for every linear toral automorphism, especially the non-hyperbolic ones, the entropies of ergodic measures form a dense set on the interval from zero to the topological entropy.
Resummation of High Order Corrections in Higgs Boson Plus Jet Production at the LHCFeb 25 2016We study the effect of multiple parton radiation to Higgs boson plus jet production at the LHC, by applying the transverse momentum dependent (TMD) factorization formalism to resum large logarithmic contributions to all orders in the expansion of the ... More
Soft Factor Subtraction and Transverse Momentum Dependent Parton Distributions on LatticeMay 29 2014We study the transverse momentum dependent (TMD) parton distributions in the newly proposed quasi-parton distribution function framework in Euclidean space. A soft factor subtraction is found to be essential to make the TMDs calculable on lattice. We ... More
Probing the Conformations of Single Molecule via Photon Counting StatisticsNov 12 2014We suggest an approach to detect the conformation of single molecule by using the photon counting statistics. The generalized Smoluchoswki equation is employed to describe the dynamical process of conformational change of single molecule. The resonant ... More
Hunting eta_b through radiative decay into J/psiDec 14 2006Jan 25 2007We propose that the radiative decay process, \eta_b\to J/\psi\gamma, may serve as a clean searching mode for \eta_b in hadron collision facilities. By a perturbative QCD calculation, we estimate the corresponding branching ratio to be of order 10^{-7}. ... More
A lightweight forum-based distributed requirement elicitation process for open source communityOct 11 2012Nowadays, lots of open source communities adopt forum to acquire scattered stakeholders' requirements. But the requirements collection process always suffers from the unformatted description and unfocused discussions. In this paper, we establish a framework ... More
Resource Allocation in Cloud Radio Access Networks with Device-to-Device CommunicationsSep 14 2017To alleviate the burdens on the fronthaul and reduce the transmit latency, the device-to-device (D2D) communication is presented in cloud radio access networks (C-RANs). Considering dynamic traffic arrivals and time-varying channel conditions, the resource ... More
Compositional Network EmbeddingApr 17 2019Apr 18 2019Network embedding has proved extremely useful in a variety of network analysis tasks such as node classification, link prediction, and network visualization. Almost all the existing network embedding methods learn to map the node IDs to their corresponding ... More
Improved Exponential Time Lower Bound of Knapsack Problem under BT modelJun 14 2006M.Alekhnovich et al. recently have proposed a model of algorithms, called BT model, which covers Greedy, Backtrack and Simple Dynamic Programming methods and can be further divided into fixed, adaptive and fully adaptive three kinds, and have proved exponential ... More
Driving conditions dependence of magneto-electroluminescence in tri-(8-hydroxyquinoline)-aluminum based organic light emitting diodesJun 17 2011we investigated the magneto-electroluminescence (MEL) in tri-(8-hydroxyquinoline)-aluminum based organic light-emitting diodes (OLEDs) through the steady-state and transient method simultaneously. The MELs show the great different behaviors when we turn ... More
Energy-Efficient Relaying over Multiple Slots with Causal CSIMay 22 2012Nov 29 2012In many communication scenarios, such as in cellular systems, the energy cost is substantial and should be conserved, yet there is a growing need to support many real-time applications that require timely data delivery. To model such a scenario, in this ... More
A data-driven adaptive regularization method and its applicationsJul 17 2018Regularization method and Bayesian inverse method are two dominating ways for solving inverse problems generated from various fields, e.g., seismic exploration and medical imaging. The two methods are related with each other by the MAP estimates of posterior ... More
Modulated Unit-Norm Tight Frames for Compressed SensingNov 27 2014In this paper, we propose a compressed sensing (CS) framework that consists of three parts: a unit-norm tight frame (UTF), a random diagonal matrix and a column-wise orthonormal matrix. We prove that this structure satisfies the restricted isometry property ... More
Resummation of High Order Corrections in $Z$ Boson Plus Jet Production at the LHCOct 09 2018Apr 30 2019We study the multiple soft gluon radiation effects in $Z$ boson plus jet production at the LHC. By applying the transverse momentum dependent factorization formalism, the large logarithms introduced by the small total transverse momentum of the $Z$ boson ... More
What Do Deep CNNs Learn About Objects?Apr 09 2015Deep convolutional neural networks learn extremely powerful image representations, yet most of that power is hidden in the millions of deep-layer parameters. What exactly do these parameters represent? Recent work has started to analyse CNN representations, ... More
Learning Deep Object Detectors from 3D ModelsDec 22 2014Oct 12 2015Crowdsourced 3D CAD models are becoming easily accessible online, and can potentially generate an infinite number of training images for almost any object category.We show that augmenting the training data of contemporary Deep Convolutional Neural Net ... More
Application of Machine Learning in Wireless Networks: Key Techniques and Open IssuesSep 24 2018Mar 01 2019As a key technique for enabling artificial intelligence, machine learning (ML) is capable of solving complex problems without explicit programming. Motivated by its successful applications to many practical tasks like image recognition, both industry ... More
Optimizing Network Performance for Distributed DNN Training on GPU Clusters: ImageNet/AlexNet Training in 1.5 MinutesFeb 19 2019Mar 16 2019It is important to scale out deep neural network (DNN) training for reducing model training time. The high communication overhead is one of the major performance bottlenecks for distributed DNN training across multiple GPUs. Our investigations have shown ... More
3D spherical-cap fitting procedure for (truncated) sessile nano- and micro-droplets & -bubblesJun 05 2017In the study of nanobubbles, nanodroplets or nanolenses immobilised on a substrate, a cross-section of a spherical-cap is widely applied to extract geometrical information from atomic force microscopy (AFM) topographic images. In this paper, we have developed ... More
An Algorithmic Framework of Variable Metric Over-Relaxed Hybrid Proximal Extra-Gradient MethodMay 16 2018Jun 08 2018We propose a novel algorithmic framework of Variable Metric Over-Relaxed Hybrid Proximal Extra-gradient (VMOR-HPE) method with a global convergence guarantee for the maximal monotone operator inclusion problem. Its iteration complexities and local linear ... More
Collective effects of multi-scatterer on coherent propagation of photon in a two dimensional networkDec 22 2012Jul 22 2013We study the collective phenomenon in the scattering of a single-photon by one or two layers of two-level atoms. By modeling the photon dispersion with a two-dimensional (2D) coupled cavity array, we analytically derive the scattering probability of a ... More
Topological Dirac semimetal phases in InSb/$α$-Sn semiconductor superlatticesJul 15 2016We demonstrate theoretically the coexistence of Dirac semimetal and topological insulator phases in InSb/$\alpha$-Sn conventional semiconductor superlattices, based on advanced first-principles calculations combined with low-energy $k\cdot p$ theory. ... More
Universal Non-perturbative Functions for SIDIS and Drell-Yan ProcessesJun 11 2014Mar 20 2015We update the well-known BLNY fit to the low transverse momentum Drell-Yan lepton pair productions in hadronic collisions, by considering the constraints from the semi-inclusive hadron production in deep inelastic scattering (SIDIS) from HERMES and COMPASS ... More
Reciprocal Recommendation System for Online DatingJan 26 2015Jan 27 2015Online dating sites have become popular platforms for people to look for potential romantic partners. Different from traditional user-item recommendations where the goal is to match items (e.g., books, videos, etc) with a user's interests, a recommendation ... More
GraphH: High Performance Big Graph Analytics in Small ClustersMay 16 2017Aug 07 2017It is common for real-world applications to analyze big graphs using distributed graph processing systems. Popular in-memory systems require an enormous amount of resources to handle big graphs. While several out-of-core approaches have been proposed ... More
Rebuilding of destroyed spin squeezing in noisy environmentsNov 07 2017We investigate the process of spin squeezing in a ferromagnetic dipolar spin-1 Bose-Einstein condensate under the driven oneaxis twisting scheme, with emphasis on the detrimental effect of noisy environments (stray magnetic fields) which completely destroy ... More
Efficient generation of many-body singlet states of spin-1 bosons in optical superlatticesJun 06 2017We propose an efficient stepwise adiabatic merging (SAM) method to generate many-body singlet states in antiferromagnetic spin-1 bosons in concatenated optical superlattices with isolated double-well arrays, by adiabatically ramping up the double-well ... More
Quantum transport through three-dimensional topological insulator p-n junction under magnetic fieldAug 23 2018The 3D topological insulator (TI) PN junction under magnetic fields presents a novel transport property which is investigated both theoretically and numerically in this paper. Transport in this device can be tuned by the axial magnetic field. Specifically, ... More
SFCSD: A Self-Feedback Correction System for DNS Based on Active and Passive MeasurementApr 21 2017Domain Name System (DNS), one of the important infrastructure in the Internet, was vulnerable to attacks, for the DNS designer didn't take security issues into consideration at the beginning. The defects of DNS may lead to users' failure of access to ... More
Uniform Recovery Bounds for Structured Random Matrices in Corrupted Compressed SensingJun 28 2017Feb 07 2018We study the problem of recovering an $s$-sparse signal $\mathbf{x}^{\star}\in\mathbb{C}^n$ from corrupted measurements $\mathbf{y} = \mathbf{A}\mathbf{x}^{\star}+\mathbf{z}^{\star}+\mathbf{w}$, where $\mathbf{z}^{\star}\in\mathbb{C}^m$ is a $k$-sparse ... More
Resummation of High Order Corrections in $Z$ Boson Plus Jet Production at the LHCOct 09 2018We study the multiple soft gluon radiation effects in $Z$ boson plus jet production at the LHC. By applying the transverse momentum dependent factorization formalism, the large logarithms introduced by the small total transverse momentum of the $Z$ boson ... More
Improving Localization Accuracy in Connected Vehicle Networks Using Rao-Blackwellized Particle Filters: Theory, Simulations, and ExperimentsFeb 19 2017Mar 26 2017A crucial function for automated vehicle technologies is accurate localization. Lane-level accuracy is not readily available from low-cost Global Navigation Satellite System (GNSS) receivers because of factors such as multipath error and atmospheric bias. ... More
Mobile Formation Coordination and Tracking Control for Multiple Non-holonomic VehiclesFeb 28 2019This paper addresses forward motion control for trajectory tracking and mobile formation coordination for a group of non-holonomic vehicles on SE(2). Firstly, by constructing an intermediate attitude variable which involves vehicles' position information ... More
Joint Channel-Estimation/Decoding with Frequency-Selective Channels and Few-Bit ADCsJul 06 2018Dec 09 2018We propose a fast and near-optimal approach to joint channel-estimation, equalization, and decoding of coded single-carrier (SC) transmissions over frequency-selective channels with few-bit analog-to-digital converters (ADCs). Our approach leverages parametric ... More
ExFuse: Enhancing Feature Fusion for Semantic SegmentationApr 11 2018Modern semantic segmentation frameworks usually combine low-level and high-level features from pre-trained backbone convolutional models to boost performance. In this paper, we first point out that a simple fusion of low-level and high-level features ... More
A Fast Integrated Planning and Control Framework for Autonomous Driving via Imitation LearningJul 09 2017For safe and efficient planning and control in autonomous driving, we need a driving policy which can achieve desirable driving quality in long-term horizon with guaranteed safety and feasibility. Optimization-based approaches, such as Model Predictive ... More
Cross-Layer Adaptive Feedback Scheduling of Wireless Control SystemsSep 29 2008There is a trend towards using wireless technologies in networked control systems. However, the adverse properties of the radio channels make it difficult to design and implement control systems in wireless environments. To attack the uncertainty in available ... More
MetaFlow: a Scalable Metadata Lookup Service for Distributed File Systems in Data CentersNov 05 2016Nov 10 2016In large-scale distributed file systems, efficient meta- data operations are critical since most file operations have to interact with metadata servers first. In existing distributed hash table (DHT) based metadata management systems, the lookup service ... More
Security of a new two-way continuous-variable quantum key distribution protocolOct 09 2011Aug 27 2012The original two-way continuous-variable quantum-key-distribution (CV QKD) protocols [S. Pirandola, S. Mancini, S. Lloyd, and S. L. Braunstein, Nature Physics 4, 726 (2008)] give the security against the collective attack on the condition of the tomography ... More
On Lower Bound of Worst Case Error Probability for Quantum Fingerprinting with Shared EntanglementJun 14 2006This paper discusses properties of quantum fingerprinting with shared entanglement. Under certain restriction of final measurement, a relation is given between unitary operations of two parties. Then, by reducing to spherical coding problem, this paper ... More
Large Kernel Matters -- Improve Semantic Segmentation by Global Convolutional NetworkMar 08 2017One of recent trends [30, 31, 14] in network architec- ture design is stacking small filters (e.g., 1x1 or 3x3) in the entire network because the stacked small filters is more ef- ficient than a large kernel, given the same computational complexity. However, ... More
$B_c$ Exclusive Decays to Charmonium and a Light Meson at Next-to-Leading Order AccuracySep 26 2012Dec 02 2013In this paper the next-to-leading order (NLO) corrections to $B_c$ meson exclusive decays to S-wave charmonia and light pseudoscalar or vector mesons, i.e. $\pi$, $K$, $\rho$, and $K^*$, are performed within non-relativistic (NR) QCD approach. The non-factorizable ... More
GraphMP: I/O-Efficient Big Graph Analytics on a Single Commodity MachineOct 09 2018Feb 18 2019Recent studies showed that single-machine graph processing systems can be as highly competitive as cluster-based approaches on large-scale problems. While several out-of-core graph processing systems and computation models have been proposed, the high ... More
GraphMP: An Efficient Semi-External-Memory Big Graph Processing System on a Single MachineJul 09 2017Recent studies showed that single-machine graph processing systems can be as highly competitive as cluster-based approaches on large-scale problems. While several out-of-core graph processing systems and computation models have been proposed, the high ... More
Asset Allocation under the Basel Accord Risk MeasuresAug 06 2013Financial institutions are currently required to meet more stringent capital requirements than they were before the recent financial crisis; in particular, the capital requirement for a large bank's trading book under the Basel 2.5 Accord more than doubles ... More
Towards Distributed Machine Learning in Shared Clusters: A Dynamically-Partitioned ApproachApr 22 2017Many cluster management systems (CMSs) have been proposed to share a single cluster with multiple distributed computing systems. However, none of the existing approaches can handle distributed machine learning (ML) workloads given the following criteria: ... More
A Chunk Caching Location and Searching Scheme in Content Centric NetworkingJan 10 2017Content Centric Networking (CCN) is a new network infrastructure around content dissemination and retrieval, shift from host addresses to named data. Each CCN router has a cache to store the chunks passed by it. Therefore the caching strategy about chunk ... More
StaQC: A Systematically Mined Question-Code Dataset from Stack OverflowMar 26 2018Stack Overflow (SO) has been a great source of natural language questions and their code solutions (i.e., question-code pairs), which are critical for many tasks including code retrieval and annotation. In most existing research, question-code pairs were ... More
Robust Semantic Segmentation By Dense Fusion Network On Blurred VHR Remote Sensing ImagesMar 07 2019Robust semantic segmentation of VHR remote sensing images from UAV sensors is critical for earth observation, land use, land cover or mapping applications. Several factors such as shadows, weather disruption and camera shakes making this problem highly ... More
Hybrid Quantum-Classical Approach to Quantum Optimal ControlAug 02 2016Jan 19 2017A central challenge in quantum computing is to identify more computational problems for which utilization of quantum resources can offer significant speedup. Here, we propose a hybrid quantum-classical scheme to tackle the quantum optimal control problem. ... More
Constrained Maximum Correntropy Adaptive FilteringOct 06 2016Dec 14 2016Constrained adaptive filtering algorithms inculding constrained least mean square (CLMS), constrained affine projection (CAP) and constrained recursive least squares (CRLS) have been extensively studied in many applications. Most existing constrained ... More
The Quasi-normal Modes of Charged Scalar Fields in Kerr-Newman black hole and Its Geometric InterpretationJun 27 2015Nov 01 2015It is well-known that there is a geometric correspondence between high-frequency quasi-normal modes (QNMs) and null geodesics (spherical photon orbits). In this paper, we generalize such correspondence to charged scalar field in Kerr-Newman space-time. ... More
Compositional Network EmbeddingApr 17 2019Network embedding has proved extremely useful in a variety of network analysis tasks such as node classification, link prediction, and network visualization. Almost all the existing network embedding methods learn to map the node IDs to their corresponding ... More
Domain Agnostic Learning with Disentangled RepresentationsApr 28 2019Unsupervised model transfer has the potential to greatly improve the generalizability of deep models to novel domains. Yet the current literature assumes that the separation of target data into distinct domains is known as a priori. In this paper, we ... More
FPGA-based Acceleration System for Visual TrackingOct 12 2018Oct 15 2018Visual tracking is one of the most important application areas of computer vision. At present, most algorithms are mainly implemented on PCs, and it is difficult to ensure real-time performance when applied in the real scenario. In order to improve the ... More
|
{"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": 0.8064547181129456, "perplexity": 2947.421910805477}, "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-2019-22/segments/1558232255562.23/warc/CC-MAIN-20190520041753-20190520063753-00377.warc.gz"}
|
https://worldwidescience.org/topicpages/a/adaptive+radiation+model.html
|
NARCIS (Netherlands)
Meyer, J.R.; Schoustra, S.E.; LaChapelle, J.; Kassen, R.K.
2011-01-01
The history of life is punctuated by repeated periods of unusually rapid evolutionary diversification called adaptive radiation. The dynamics of diversity during a radiation reflect an overshooting pattern with an initial phase of exponential-like increase followed by a slower decline. Much
Energy Technology Data Exchange (ETDEWEB)
Francino, M. Pilar
2004-10-18
The evolution of new gene functions is one of the keys to evolutionary innovation. Most novel functions result from gene duplication followed by divergence. However, the models hitherto proposed to account for this process are not fully satisfactory. The classic model of neofunctionalization holds that the two paralogous gene copies resulting from a duplication are functionally redundant, such that one of them can evolve under no functional constraints and occasionally acquire a new function. This model lacks a convincing mechanism for the new gene copies to increase in frequency in the population and survive the mutational load expected to accumulate under neutrality, before the acquisition of the rare beneficial mutations that would confer new functionality. The subfunctionalization model has been proposed as an alternative way to generate genes with altered functions. This model also assumes that new paralogous gene copies are functionally redundant and therefore neutral, but it predicts that relaxed selection will affect both gene copies such that some of the capabilities of the parent gene will disappear in one of the copies and be retained in the other. Thus, the functions originally present in a single gene will be partitioned between the two descendant copies. However, although this model can explain increases in gene number, it does not really address the main evolutionary question, which is the development of new biochemical capabilities. Recently, a new concept has been introduced into the gene evolution literature which is most likely to help solve this dilemma. The key point is to allow for a period of natural selection for the duplication per se, before new function evolves, rather than considering gene duplication to be neutral as in the previous models. Here, I suggest a new model that draws on the advantage of postulating selection for gene duplication, and proposes that bursts of adaptive gene amplification in response to specific selection
Energy Technology Data Exchange (ETDEWEB)
Mellit, A. [University Centre of Medea (CUYFM), Institute of Engineering Sciences, Department of Electronics, Medea (Algeria). Department of Electrical Engineering, Faculty of Engineering; Benghanem, M. [University of Sciences Technology Houari Boumediene (USTHB), Algiers (Algeria). Faculty of Electrical Engineering; Kalogirou, S.A. [Higher Technical Institute, Nicosia (Cyprus). Department of Mechanical Engineering
2006-07-15
The combination of wavelet theory and neural networks has lead to the development of wavelet networks. Wavelet-networks are feed-forward networks using wavelets as activation functions. Wavelet-networks have been used successfully in various engineering applications such as classification, identification and control problems. In this paper, the use of adaptive wavelet-network architecture in finding a suitable forecasting model for predicting the daily total solar-radiation is investigated. Total solar-radiation is considered as the most important parameter in the performance prediction of renewable energy systems, particularly in sizing photovoltaic (PV) power systems. For this purpose, daily total solar-radiation data have been recorded during the period extending from 1981 to 2001, by a meteorological station in Algeria. The wavelet-network model has been trained by using either the 19 years of data or one year of the data. In both cases the total solar radiation data corresponding to year 2001 was used for testing the model. The network was trained to accept and handle a number of unusual cases. Results indicate that the model predicts daily total solar-radiation values with a good accuracy of approximately 97% and the mean absolute percentage error is not more than 6%. In addition, the performance of the model was compared with different neural network structures and classical models. Training algorithms for wavelet-networks require smaller numbers of iterations when compared with other neural networks. The model can be used to fill missing data in weather databases. Additionally, the proposed model can be generalized and used in different locations and for other weather data, such as sunshine duration and ambient temperature. Finally, an application using the model for sizing a PV-power system is presented in order to confirm the validity of this model. (author)
4. Effect of modeled microgravity on radiation-induced adaptive response of root growth in Arabidopsis thaliana.
Science.gov (United States)
Deng, Chenguang; Wang, Ting; Wu, Jingjing; Xu, Wei; Li, Huasheng; Liu, Min; Wu, Lijun; Lu, Jinying; Bian, Po
2017-02-01
5. Lack of high-dose radiation mediated prostate cancer promotion and low-dose radiation adaptive response in the TRAMP mouse model.
Science.gov (United States)
Lawrence, M D; Ormsby, R J; Blyth, B J; Bezak, E; England, G; Newman, M R; Tilley, W D; Sykes, P J
2013-10-01
Science.gov (United States)
Gomez, Daniel R.; Chang, Joe Y.
2011-01-01
Science.gov (United States)
Campa, Alessandro; Esposito, Giuseppe; Belli, Mauro
8. TH-A-BRF-02: BEST IN PHYSICS (JOINT IMAGING-THERAPY) - Modeling Tumor Evolution for Adaptive Radiation Therapy
Energy Technology Data Exchange (ETDEWEB)
Liu, Y; Lee, CG [University of Toronto, Toronto, ON (Canada); Chan, TCY [University of Toronto, Toronto, ON (Canada); Techna Institute for the Advancement of Technology for Health, Toronto, ON (Canada); Cho, YB; Islam, MK [University of Toronto, Toronto, ON (Canada); Princess Margaret Hospital, Toronto, ON (Canada); Ontario Consortium for Adaptive Interventions in Radiation Oncology (OCAIRO) (Canada)
2014-06-15
Purpose: To develop mathematical models of tumor geometry changes under radiotherapy that may support future adaptive paradigms. Methods: A total of 29 cervical patients were scanned using MRI, once for planning and weekly thereafter for treatment monitoring. Using the tumor volumes contoured by a radiologist, three mathematical models were investigated based on the assumption of a stochastic process of tumor evolution. The “weekly MRI” model predicts tumor geometry for the following week from the last two consecutive MRI scans, based on the voxel transition probability. The other two models use only the first pair of consecutive MRI scans, and the transition probabilities were estimated via tumor type classified from the entire data set. The classification is based on either measuring the tumor volume (the “weekly volume” model), or implementing an auxiliary “Markov chain” model. These models were compared to a constant volume approach that represents the current clinical practice, using various model parameters; e.g., the threshold probability β converts the probability map into a tumor shape (larger threshold implies smaller tumor). Model performance was measured using volume conformity index (VCI), i.e., the union of the actual target and modeled target volume squared divided by product of these two volumes. Results: The “weekly MRI” model outperforms the constant volume model by 26% on average, and by 103% for the worst 10% of cases in terms of VCI under a wide range of β. The “weekly volume” and “Markov chain” models outperform the constant volume model by 20% and 16% on average, respectively. They also perform better than the “weekly MRI” model when β is large. Conclusion: It has been demonstrated that mathematical models can be developed to predict tumor geometry changes for cervical cancer undergoing radiotherapy. The models can potentially support adaptive radiotherapy paradigm by reducing normal tissue dose. This research
9. Predictive models for regional hepatic function based on 99mTc-IDA SPECT and local radiation dose for physiologic adaptive radiation therapy.
Science.gov (United States)
Wang, Hesheng; Feng, Mary; Frey, Kirk A; Ten Haken, Randall K; Lawrence, Theodore S; Cao, Yue
2013-08-01
High-dose radiation therapy (RT) for intrahepatic cancer is limited by the development of liver injury. This study investigated whether regional hepatic function assessed before and during the course of RT using 99mTc-labeled iminodiacetic acid (IDA) single photon emission computed tomography (SPECT) could predict regional liver function reserve after RT. Fourteen patients treated with RT for intrahepatic cancers underwent dynamic 99mTc-IDA SPECT scans before RT, during, and 1 month after completion of RT. Indocyanine green (ICG) tests, a measure of overall liver function, were performed within 1 day of each scan. Three-dimensional volumetric hepatic extraction fraction (HEF) images of the liver were estimated by deconvolution analysis. After coregistration of the CT/SPECT and the treatment planning CT, HEF dose-response functions during and after RT were generated. The volumetric mean of the HEFs in the whole liver was correlated with ICG clearance time. Three models, dose, priori, and adaptive models, were developed using multivariate linear regression to assess whether the regional HEFs measured before and during RT helped predict regional hepatic function after RT. The mean of the volumetric liver HEFs was significantly correlated with ICG clearance half-life time (r=-0.80, Padaptive model, regional HEF after RT was predicted by regional HEF reassessed during RT and the remaining planned local dose (R=0.83, Padaptive radiation treatment strategies to maximize tumor control and minimize the risk of liver damage. Published by Elsevier Inc.
10. RTTOV-gb - adapting the fast radiative transfer model RTTOV for the assimilation of ground-based microwave radiometer observations
Science.gov (United States)
De Angelis, Francesco; Cimini, Domenico; Hocking, James; Martinet, Pauline; Kneifel, Stefan
2016-08-01
Ground-based microwave radiometers (MWRs) offer a new capability to provide continuous observations of the atmospheric thermodynamic state in the planetary boundary layer. Thus, they are potential candidates to supplement radiosonde network and satellite data to improve numerical weather prediction (NWP) models through a variational assimilation of their data. However in order to assimilate MWR observations, a fast radiative transfer model is required and such a model is not currently available. This is necessary for going from the model state vector space to the observation space at every observation point. The fast radiative transfer model RTTOV is well accepted in the NWP community, though it was developed to simulate satellite observations only. In this work, the RTTOV code has been modified to allow for simulations of ground-based upward-looking microwave sensors. In addition, the tangent linear, adjoint, and K-modules of RTTOV have been adapted to provide Jacobians (i.e., the sensitivity of observations to the atmospheric thermodynamical state) for ground-based geometry. These modules are necessary for the fast minimization of the cost function in a variational assimilation scheme. The proposed ground-based version of RTTOV, called RTTOV-gb, has been validated against accurate and less time-efficient line-by-line radiative transfer models. In the frequency range commonly used for temperature and humidity profiling (22-60 GHz), root-mean-square brightness temperature differences are smaller than typical MWR uncertainties (˜ 0.5 K) at all channels used in this analysis. Brightness temperatures (TBs) computed with RTTOV-gb from radiosonde profiles have been compared with nearly simultaneous and co-located ground-based MWR observations. Differences between simulated and measured TBs are below 0.5 K for all channels except for the water vapor band, where most of the uncertainty comes from instrumental errors. The Jacobians calculated with the K-module of RTTOV
11. Principal component analysis-based anatomical motion models for use in adaptive radiation therapy of head and neck cancer patients
Science.gov (United States)
Chetvertkov, Mikhail A.
Purpose: To develop standard and regularized principal component analysis (PCA) models of anatomical changes from daily cone beam CTs (CBCTs) of head and neck (H&N) patients, assess their potential use in adaptive radiation therapy (ART), and to extract quantitative information for treatment response assessment. Methods: Planning CT (pCT) images of H&N patients were artificially deformed to create "digital phantom" images, which modeled systematic anatomical changes during Radiation Therapy (RT). Artificial deformations closely mirrored patients' actual deformations, and were interpolated to generate 35 synthetic CBCTs, representing evolving anatomy over 35 fractions. Deformation vector fields (DVFs) were acquired between pCT and synthetic CBCTs (i.e., digital phantoms), and between pCT and clinical CBCTs. Patient-specific standard PCA (SPCA) and regularized PCA (RPCA) models were built from these synthetic and clinical DVF sets. Eigenvectors, or eigenDVFs (EDVFs), having the largest eigenvalues were hypothesized to capture the major anatomical deformations during treatment. Modeled anatomies were used to assess the dose deviations with respect to the planned dose distribution. Results: PCA models achieve variable results, depending on the size and location of anatomical change. Random changes prevent or degrade SPCA's ability to detect underlying systematic change. RPCA is able to detect smaller systematic changes against the background of random fraction-to-fraction changes, and is therefore more successful than SPCA at capturing systematic changes early in treatment. SPCA models were less successful at modeling systematic changes in clinical patient images, which contain a wider range of random motion than synthetic CBCTs, while the regularized approach was able to extract major modes of motion. For dose assessment it has been shown that the modeled dose distribution was different from the planned dose for the parotid glands due to their shrinkage and shift into
Science.gov (United States)
Flohr, Régis C E; Blom, Carsten J; Rainey, Paul B; Beaumont, Hubertus J E
2013-12-17
13. Adaptive radiation within marine anisakid nematodes: a zoogeographical modeling of cosmopolitan, zoonotic parasites.
Directory of Open Access Journals (Sweden)
Thomas Kuhn
Full Text Available Parasites of the nematode genus Anisakis are associated with aquatic organisms. They can be found in a variety of marine hosts including whales, crustaceans, fish and cephalopods and are known to be the cause of the zoonotic disease anisakiasis, a painful inflammation of the gastro-intestinal tract caused by the accidental consumptions of infectious larvae raw or semi-raw fishery products. Since the demand on fish as dietary protein source and the export rates of seafood products in general is rapidly increasing worldwide, the knowledge about the distribution of potential foodborne human pathogens in seafood is of major significance for human health. Studies have provided evidence that a few Anisakis species can cause clinical symptoms in humans. The aim of our study was to interpolate the species range for every described Anisakis species on the basis of the existing occurrence data. We used sequence data of 373 Anisakis larvae from 30 different hosts worldwide and previously published molecular data (n = 584 from 53 field-specific publications to model the species range of Anisakis spp., using a interpolation method that combines aspects of the alpha hull interpolation algorithm as well as the conditional interpolation approach. The results of our approach strongly indicate the existence of species-specific distribution patterns of Anisakis spp. within different climate zones and oceans that are in principle congruent with those of their respective final hosts. Our results support preceding studies that propose anisakid nematodes as useful biological indicators for their final host distribution and abundance as they closely follow the trophic relationships among their successive hosts. The modeling might although be helpful for predicting the likelihood of infection in order to reduce the risk of anisakiasis cases in a given area.
14. Laboratory model of adaptive radiation: a selection experiment in the bank vole.
Science.gov (United States)
Sadowska, Edyta T; Baliga-Klimczyk, Katarzyna; Chrzaścik, Katarzyna M; Koteja, Paweł
2008-01-01
In a laboratory colony of a wild rodent, the bank vole Myodes (=Clethrionomys) glareolus, a multiway artificial selection experiment was applied to mimic evolution toward high aerobic metabolism achieved during locomotor activity, predatory behavior, and ability to cope with herbivorous diet. Four lines for each of the selection directions and four unselected control lines have been maintained. After three generations of within-family selection, the maximum rate of oxygen consumption achieved during swimming was 15% higher in the selected than in the control lines (least square means, adjusted for body mass: 252.0 vs. 218.6 mL O(2)/h, P = 0.0001). When fed a low-quality diet made of dried grass, voles from the lines selected for ability to cope with herbivorous diet lost about 0.7 g less mass than voles from the control lines (-2.44 vs. -3.16 g/4 d, P = 0.008). In lines selected for predatory behavior toward crickets, proportion of "predatory" individuals was higher than in the control lines (43.6% vs. 24.9%; P = 0.045), but "time to capture" calculated for the successful trials did not differ between the lines. The experiment continues, and the selected lines of voles will provide a unique model for testing hypotheses concerning correlated evolution of complex traits.
National Research Council Canada - National Science Library
Sergey Gavrilets; Jonathan B. Losos
2009-01-01
.... Adaptive radiation in such clades is not only spectacular, but is also an extremely complex process influenced by a variety of ecological, genetic, and developmental factors and strongly dependent...
National Research Council Canada - National Science Library
Guzmán, Beatriz; Lledó, María Dolores; Vargas, Pablo
2009-01-01
Adaptive radiation in Mediterranean plants is poorly understood. The white-flowered Cistus lineage consists of 12 species primarily distributed in Mediterranean habitats and is herein subject to analysis...
17. Standard and reduced radiation dose liver CT images: adaptive statistical iterative reconstruction versus model-based iterative reconstruction-comparison of findings and image quality.
Science.gov (United States)
Shuman, William P; Chan, Keith T; Busey, Janet M; Mitsumori, Lee M; Choi, Eunice; Koprowicz, Kent M; Kanal, Kalpana M
2014-12-01
Energy Technology Data Exchange (ETDEWEB)
Scott, Bobby R. [Lovelace Biomedical and Environmental Research Inst., Albuquerque, NM (United States); Lin, Yong [Lovelace Biomedical and Environmental Research Inst., Albuquerque, NM (United States); Wilder, Julie [Lovelace Biomedical and Environmental Research Inst., Albuquerque, NM (United States); Belinsky, Steven [Lovelace Biomedical and Environmental Research Inst., Albuquerque, NM (United States)
2015-03-01
Our main research objective was to determine the biological bases for low-dose, radiation-induced adaptive responses in the lung and use the knowledge gained to produce an improved risk model for radiation-induced lung cancer that accounts for activated natural protection, genetic influences, and the role of epigenetic regulation (epiregulation). Currently, low-dose radiation risk assessment is based on the linear-no-threshold hypothesis which now is known to be unsupported by a large volume of data.
19. Adaption of the Air Weather Service Fog Model to Forecast Radiation Fog Events in the Southeast United States
Science.gov (United States)
1997-03-01
First, I must thank James O’Sullivan from St. Louis University. Your assistance in providing the fog model program and your answers to my many questions...Numerical Forecasting of Radiation Fog. Part I: Numerical Model and Sensitivity Tests. Mon. Wea. Rev.., 122, 1218-1230. Dyer R. M., and F. L. Gerald , 1989...pp. Holton , J. R., 1992: An Introduction to Dynamic Meteorology. 3rd Ed., Academic Press, 511 pp. Mahrt, L., M. Ek, J. Kim, and A. A. M. Holtslag, 1991
20. RTTOV-gb - Adapting the fast radiative transfer model RTTOV for the assimilation of ground-based microwave radiometer observations
Science.gov (United States)
De Angelis, Francesco; Cimini, Domenico; Hocking, James; Martinet, Pauline; Kneifel, Stefan
2016-04-01
Energy Technology Data Exchange (ETDEWEB)
Gould, Michael N. [Univ. of Wisconsin, Madison, WI (United States)
2015-06-30
The overall hypothesis of this grant application is that the adaptive responses elicited by low dose ionizing radiation (LDIR) result in part from heritable DNA methylation changes in the epigenome. In the final budget period at the University of Wisconsin-Madison, we will specifically address this hypothesis by determining if the epigenetically labile, differentially methylated regions (DMRs) that regulate parental-specific expression of imprinted genes are deregulated in agouti mice by low dose radiation exposure during gestation. This information is particularly important to ascertain given the 1) increased human exposure to medical sources of radiation; 2) increased number of people predicted to live and work in space; and 3) enhanced citizen concern about radiation exposure from nuclear power plant accidents and terrorist ‘dirty bombs.’
Energy Technology Data Exchange (ETDEWEB)
NONE
1993-08-01
French scientists discovered radioactivity and developed vaccination, so it is perhaps appropriate that a prominent French cancer specialist should be promoting the idea of a radiation vaccination effect - or radiation adaptation, as he prefers to call it. Raymond Latarjet, of the Institut Curie in Paris, maintains that recent studies at the gene level are showing evidence that with low doses of radiation, there is time for a cell repair mechanism to take effect, and that this seems to provide some protection against subsequent exposure to high doses. He cited experiments in his laboratory in which exposure to a dose of 4 Gy (400 rad) had, predictably, produced a large number of gene mutations in a specimen, but the number of mutations was less than half that number in a specimen that had been exposed to a dose of 0.02 Gy some six hours before exposure to the 4 Gy.
Science.gov (United States)
Böck, Michelle; Eriksson, Kjell; Forsgren, Anders; Hårdemark, Björn
2017-06-01
-at-risk protection. In case of unpredictably larger treatment errors, the first strategy in combination with at most weekly adaptation performs best at notably improving treatment quality in terms of target coverage and organ-at-risk protection in comparison with a non-adaptive approach and the other adaptive strategies. The authors present a framework that provides robust plan re-optimization or margin adaptation of a treatment plan in response to interfractional geometric errors throughout the fractionated treatment. According to the simulations, these robust adaptive treatment strategies are able to identify candidates for an adaptive treatment, thus giving the opportunity to provide individualized plans, and improve their treatment quality through adaptation. The simulated robust adaptive framework is a guide for further development of optimally controlled robust adaptive therapy models. © 2017 American Association of Physicists in Medicine.
Science.gov (United States)
Jørgensen, Jes; Brinch, Christian; Girart, Josep Miquel; Padovani, Marco; Frau, Pau; Schaaf, Reinhold; Kuiper, Rolf; Bertoldi, Frank; Hogerheijde, Michiel; Juhasz, Attila; Vlemmings, Wouter
2014-02-01
ARTIST is a suite of tools for comprehensive multi-dimensional radiative transfer calculations of dust and line emission, as well as their polarization, to help interpret observations from submillimeter telescopes. The ARTIST package consists of LIME, a radiative transfer code that uses adaptive gridding allowing simulations of sources with arbitrary multi-dimensional (1D, 2D, 3D) and time-dependent structures, thus ensuring rapid convergence; the DustPol and LinePol tools for modeling the polarization of the line and dust emission; and an interface run from Python scripts that manages the interaction between a general model library and LIME, and a graphical interface to simulate images.
Science.gov (United States)
Guzmán, Beatriz; Lledó, María Dolores; Vargas, Pablo
2009-01-01
Background Adaptive radiation in Mediterranean plants is poorly understood. The white-flowered Cistus lineage consists of 12 species primarily distributed in Mediterranean habitats and is herein subject to analysis. Methodology/Principal Findings We conducted a “total evidence” analysis combining nuclear (ncpGS, ITS) and plastid (trnL-trnF, trnK-matK, trnS-trnG, rbcL) DNA sequences and using MP and BI to test the hypothesis of radiation as suggested by previous phylogenetic results. One of the five well-supported lineages of the Cistus-Halimium complex, the white-flowered Cistus lineage, comprises the higher number of species (12) and is monophyletic. Molecular dating estimates a Mid Pleistocene (1.04±0.25 Ma) diversification of the white-flowered lineage into two groups (C. clusii and C. salviifolius lineages), which display asymmetric characteristics: number of species (2 vs. 10), leaf morphologies (linear vs. linear to ovate), floral characteristics (small, three-sepalled vs. small to large, three- or five-sepalled flowers) and ecological attributes (low-land vs. low-land to mountain environments). A positive phenotype-environment correlation has been detected by historical reconstructions of morphological traits (leaf shape, leaf labdanum content and leaf pubescence). Ecological evidence indicates that modifications of leaf shape and size, coupled with differences in labdanum secretion and pubescence density, appear to be related to success of new species in different Mediterranean habitats. Conclusions/Significance The observation that radiation in the Cistus salviifolius lineage has been accompanied by the emergence of divergent leaf traits (such as shape, pubescence and labdanum secretion) in different environments suggets that radiation in the group has been adaptive. Here we argued that the diverse ecological conditions of Mediterranean habitats played a key role in directing the evolution of alternative leaf strategies in this plant group. Key
Directory of Open Access Journals (Sweden)
Beatriz Guzmán
Full Text Available BACKGROUND: Adaptive radiation in Mediterranean plants is poorly understood. The white-flowered Cistus lineage consists of 12 species primarily distributed in Mediterranean habitats and is herein subject to analysis. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a "total evidence" analysis combining nuclear (ncpGS, ITS and plastid (trnL-trnF, trnK-matK, trnS-trnG, rbcL DNA sequences and using MP and BI to test the hypothesis of radiation as suggested by previous phylogenetic results. One of the five well-supported lineages of the Cistus-Halimium complex, the white-flowered Cistus lineage, comprises the higher number of species (12 and is monophyletic. Molecular dating estimates a Mid Pleistocene (1.04+/-0.25 Ma diversification of the white-flowered lineage into two groups (C. clusii and C. salviifolius lineages, which display asymmetric characteristics: number of species (2 vs. 10, leaf morphologies (linear vs. linear to ovate, floral characteristics (small, three-sepalled vs. small to large, three- or five-sepalled flowers and ecological attributes (low-land vs. low-land to mountain environments. A positive phenotype-environment correlation has been detected by historical reconstructions of morphological traits (leaf shape, leaf labdanum content and leaf pubescence. Ecological evidence indicates that modifications of leaf shape and size, coupled with differences in labdanum secretion and pubescence density, appear to be related to success of new species in different Mediterranean habitats. CONCLUSIONS/SIGNIFICANCE: The observation that radiation in the Cistus salviifolius lineage has been accompanied by the emergence of divergent leaf traits (such as shape, pubescence and labdanum secretion in different environments suggets that radiation in the group has been adaptive. Here we argued that the diverse ecological conditions of Mediterranean habitats played a key role in directing the evolution of alternative leaf strategies in this plant group
7. Analysis and adaptation of a mathematical model for the prediction of solar radiation; Analisis y adaptacion de un modelo matematico de prediccion de radiacion solar
Energy Technology Data Exchange (ETDEWEB)
Zambrano, Lorenzo [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)
1986-12-31
There is an abundant, reliable, free, source of energy whose use can be planned and besides, practicably inexhaustible: the solar energy. In Mexico it constitutes an important resource, because of its geographical position; for this reason it is fundamental to know it well, either by means of measurements conducted for several years or by mathematical models. These last ones predict with meteorological variables, the values of the solar radiation with acceptable precision. At the Instituto de Investigaciones Electricas (IIE) a model is studied for the prediction of the solar radiation to be adapted to the local conditions of Mexico. It is used in simulation studies of the solar plants functioning and other solar systems. [Espanol] Existe una fuente de energia abundante, confiable, gratuita, cuyo uso puede planearse y, ademas, es practicamente inagotable: la solar. En Mexico constituye un recurso importante, por la posicion geografica del pais; por eso es fundamental conocerlo bien, ya mediante mediciones realizadas durante algunos anos, ya mediante modelos matematicos. Estos ultimos predicen, con datos de variables meteorologicas, los valores de la radiacion solar con precision aceptable. En el Instituto de Investigaciones Electricas (IIE) se estudia un modelo de prediccion de radiacion solar para adaptarlo a las condiciones locales de Mexico. Se usa en estudios de simulacion del funcionamiento de plantas helioelectricas y otros sistemas solares.
Directory of Open Access Journals (Sweden)
Renaud Séguier
2009-01-01
Full Text Available Active Appearance Models (AAMs are able to align efficiently known faces under duress, when face pose and illumination are controlled. We propose Adapted Active Appearance Models to align unknown faces in unknown poses and illuminations. Our proposal is based on the one hand on a specific transformation of the active model texture in an oriented map, which changes the AAM normalization process; on the other hand on the research made in a set of different precomputed models related to the most adapted AAM for an unknown face. Tests on public and private databases show the interest of our approach. It becomes possible to align unknown faces in real-time situations, in which light and pose are not controlled.
Science.gov (United States)
Muschick, Moritz; Indermaur, Adrian; Salzburger, Walter
2012-12-18
10. Solar radiation models - review
Directory of Open Access Journals (Sweden)
2010-05-01
Full Text Available In the design and study of solar energy, information on solar radiation and its components at a given location is very essential. Solar radiation data are required by solar engineers, architects, agriculturists and hydrologists for many applications such as solar heating, cooking, drying and interior illumination of buildings. For this purpose, in the past, several empirical correlations have been developed in order to estimate the solar radiation around the world. The main objective of this study is to review the global solar radiation models available in the literature. There are several formulae which relate global radiation to other climatic parameters such as sunshine hours, relative humidity and maximum temperature. The most commonly used parameter for estimating global solar radiation is sunshine duration. Sunshine duration can be easily and reliably measured and data are widely available.
Energy Technology Data Exchange (ETDEWEB)
Shumway, R.W.
1987-10-01
The ATHENA computer program has many features that make it desirable to use as a space reactor evaluation tool. One of the missing features was a surface-to-surface thermal radiation model. A model was developed that allows any of the regular ATHENA heat slabs to radiate to any other heat slab. The view factors and surface emissivities must be specified by the user. To verify that the model was properly accounting for radiant energy transfer, two different types of test calculations were performed. Both calculations have excellent results. The updates have been used on both the INEL CDC-176 and the Livermore Cray. 7 refs., 2 figs., 6 tabs.
12. Image quality in children with low-radiation chest CT using adaptive statistical iterative reconstruction and model-based iterative reconstruction.
Directory of Open Access Journals (Sweden)
Jihang Sun
Full Text Available OBJECTIVE: To evaluate noise reduction and image quality improvement in low-radiation dose chest CT images in children using adaptive statistical iterative reconstruction (ASIR and a full model-based iterative reconstruction (MBIR algorithm. METHODS: Forty-five children (age ranging from 28 days to 6 years, median of 1.8 years who received low-dose chest CT scans were included. Age-dependent noise index (NI was used for acquisition. Images were retrospectively reconstructed using three methods: MBIR, 60% of ASIR and 40% of conventional filtered back-projection (FBP, and FBP. The subjective quality of the images was independently evaluated by two radiologists. Objective noises in the left ventricle (LV, muscle, fat, descending aorta and lung field at the layer with the largest cross-section area of LV were measured, with the region of interest about one fourth to half of the area of descending aorta. Optimized signal-to-noise ratio (SNR was calculated. RESULT: In terms of subjective quality, MBIR images were significantly better than ASIR and FBP in image noise and visibility of tiny structures, but blurred edges were observed. In terms of objective noise, MBIR and ASIR reconstruction decreased the image noise by 55.2% and 31.8%, respectively, for LV compared with FBP. Similarly, MBIR and ASIR reconstruction increased the SNR by 124.0% and 46.2%, respectively, compared with FBP. CONCLUSION: Compared with FBP and ASIR, overall image quality and noise reduction were significantly improved by MBIR. MBIR image could reconstruct eligible chest CT images in children with lower radiation dose.
Science.gov (United States)
Erickson, Lisa
2016-01-01
The proposed technology leverages the temperature dependent phase change of shape memory alloys (SMAs) to drive the shape of a flexible radiator panel. The opening/closing of the radiator panel, as a function of temperature, passively adapts the radiator's rate of heat rejection in response to a vehicle's needs.
Science.gov (United States)
Givnish, Thomas J
2015-07-01
15. Iterative adaptive radiations of fossil canids show no evidence for diversity-dependent trait evolution.
Science.gov (United States)
Slater, Graham J
2015-04-21
Science.gov (United States)
Close, Roger A; Friedman, Matt; Lloyd, Graeme T; Benson, Roger B J
2015-08-17
A series of spectacular discoveries have transformed our understanding of Mesozoic mammals in recent years. These finds reveal hitherto-unsuspected ecomorphological diversity that suggests that mammals experienced a major adaptive radiation during the Middle to Late Jurassic. Patterns of mammalian macroevolution must be reinterpreted in light of these new discoveries, but only taxonomic diversity and limited aspects of morphological disparity have been quantified. We assess rates of morphological evolution and temporal patterns of disparity using large datasets of discrete characters. Rates of morphological evolution were significantly elevated prior to the Late Jurassic, with a pronounced peak occurring during the Early to Middle Jurassic. This intense burst of phenotypic innovation coincided with a stepwise increase in apparent long-term standing diversity and the attainment of maximum disparity, supporting a "short-fuse" model of early mammalian diversification. Rates then declined sharply, and remained significantly low until the end of the Mesozoic, even among therians. This supports the "long-fuse" model of diversification in Mesozoic therians. Our findings demonstrate that sustained morphological innovation in Triassic stem-group mammals culminated in a global adaptive radiation of crown-group members during the Early to Middle Jurassic.
National Research Council Canada - National Science Library
Patrik Nosil; Bernard J. Crespi
2006-01-01
.... The role and importance of other processes, such as predation, remains controversial. Here we use Timema stick insects to show that adaptive radiation can be driven by divergent selection from visual predators...
Science.gov (United States)
2016-11-01
Predicting the fog-onset, its growth and dissipation helps in managing airports and other modes of transport. After sunset, occurrence of fog requires moist air, low wind and clear-sky conditions. Under these circumstances radiative heat transfer plays a vital role in the NBL. Locally, initiation of fog happens when the air temperature falls below the dew-point. Thus, to predict the onset of fog at a given location, one has to compute evolution of vertical temperature profile. Earlier,our group has shown that the presence of aerosols and vertical variation in their number density determines the radiative-cooling and hence development of vertical temperature profile. Aerosols, through radiation in the window-band, provides an efficient path for air layers to lose heat to the cold, upper atmosphere. This process creates cooler air layer between warmer ground and upper air layers and resulting temperature profile facilitate the initiation of fog. Our results clearly indicates that accounting for the presence of aerosols and their radiative-transfer is important in modeling micro-meteorological process of fog formation and its evolution. DST, Govt. INDIA.
Science.gov (United States)
Tan, Jiaqi; Slattery, Matthew R; Yang, Xian; Jiang, Lin
2016-06-29
Science.gov (United States)
Herrera, James P
2017-01-01
DEFF Research Database (Denmark)
Saebi, Tina; Lien, Lasse B.; Foss, Nicolai Juul
2016-01-01
CERN Document Server
Wise, John H
2010-01-01
We describe a photon-conserving radiative transfer algorithm, using a spatially-adaptive ray tracing scheme, and its parallel implementation into the adaptive mesh refinement (AMR) cosmological hydrodynamics code, Enzo. By coupling the solver with the energy equation and non-equilibrium chemistry network, our radiation hydrodynamics framework can be utilised to study a broad range of astrophysical problems, such as stellar and black hole (BH) feedback. Inaccuracies can arise from large timesteps and poor sampling, therefore we devised an adaptive time-stepping scheme and a fast approximation of the optically-thin radiation field with multiple sources. We test the method with several radiative transfer and radiation hydrodynamics tests that are given in Iliev et al. (2006, 2009). We further test our method with more dynamical situations, for example, the propagation of an ionisation front through a Rayleigh-Taylor instability, time-varying luminosities, and collimated radiation. The test suite also includes an...
Energy Technology Data Exchange (ETDEWEB)
Kudritsky, Yu.K.; Georgievsky, A.B.; Karpov, V.I.
1993-12-31
The adoptation hypothesis of biological effectiveness of ionizing radiations is based on the recognition of the invariability of general biological laws for radiobiology and on the comprehension of life evolution regularities and axiomatic principles of environment and biota unity. The ionizing radiation factor is essential for life which could not exist beyond the radiation field. The possibility of future development of the adaptation hypothesis serves as a basis for its transformation into the theoretical foundation of radiobiology. This report discusses the aspects of the adaptation theory.
Energy Technology Data Exchange (ETDEWEB)
2014-09-01
Purpose: The widespread use of intensity modulated radiation therapy (IMRT) for cervical cancer has been limited by internal target and normal tissue motion. Such motion increases the risk of underdosing the target, especially as planning margins are reduced in an effort to reduce toxicity. This study explored 2 adaptive strategies to mitigate this risk and proposes a new, automated method that minimizes replanning workload. Methods and Materials: Thirty patients with cervical cancer participated in a prospective clinical study and underwent pretreatment and weekly magnetic resonance (MR) scans over a 5-week course of daily external beam radiation therapy. Target volumes and organs at risk (OARs) were contoured on each of the scans. Deformable image registration was used to model the accumulated dose (the real dose delivered to the target and OARs) for 2 adaptive replanning scenarios that assumed a very small PTV margin of only 3 mm to account for setup and internal interfractional motion: (1) a preprogrammed, anatomy-driven midtreatment replan (A-IMRT); and (2) a dosimetry-triggered replan driven by target dose accumulation over time (D-IMRT). Results: Across all 30 patients, clinically relevant target dose thresholds failed for 8 patients (27%) if 3-mm margins were used without replanning. A-IMRT failed in only 3 patients and also yielded an additional small reduction in OAR doses at the cost of 30 replans. D-IMRT assured adequate target coverage in all patients, with only 23 replans in 16 patients. Conclusions: A novel, dosimetry-triggered adaptive IMRT strategy for patients with cervical cancer can minimize the risk of target underdosing in the setting of very small margins and substantial interfractional motion while minimizing programmatic workload and cost.
Science.gov (United States)
Wagner, Catherine E; Harmon, Luke J; Seehausen, Ole
2012-07-19
Science.gov (United States)
Pfaender, Jobst; Hadiaty, Renny K; Schliewen, Ulrich K; Herder, Fabian
2016-01-13
Strong disruptive ecological selection can initiate speciation, even in the absence of physical isolation of diverging populations. Species evolving under disruptive ecological selection are expected to be ecologically distinct but, at least initially, genetically weakly differentiated. Strong selection and the associated fitness advantages of narrowly adapted individuals, coupled with assortative mating, are predicted to overcome the homogenizing effects of gene flow. Theoretical plausibility is, however, contrasted by limited evidence for the existence of rugged adaptive landscapes in nature. We found evidence for multiple, disruptive ecological selection regimes that have promoted divergence in the sympatric, incipient radiation of 'sharpfin' sailfin silverside fishes in ancient Lake Matano (Sulawesi, Indonesia). Various modes of ecological specialization have led to adaptive morphological differences between the species, and differently adapted morphs display significant but incomplete reproductive isolation. Individual fitness and variation in morphological key characters show that disruptive selection shapes a rugged adaptive landscape in this small but complex incipient lake fish radiation.
Science.gov (United States)
Lorion, Julien; Kiel, Steffen; Faure, Baptiste; Kawato, Masaru; Ho, Simon Y W; Marshall, Bruce; Tsuchida, Shinji; Miyazaki, Jun-Ichi; Fujiwara, Yoshihiro
2013-11-07
Science.gov (United States)
Erickson, Lisa; Bertagne, Christopher; Hartl, Darren; Witcomb, John; Cognata, Thomas
2017-01-01
9. Diversity and disparity through time in the adaptive radiation of Antarctic notothenioid fishes.
Science.gov (United States)
Colombo, M; Damerau, M; Hanel, R; Salzburger, W; Matschiner, M
2015-02-01
Science.gov (United States)
Grdina, David J.; Murley, Jeffrey S.; Miller, Richard C.; Mauceri, Helena J.; Sutton, Harold G.; Li, Jian Jian; Woloschak, Gayle E.; Weichselbaum, Ralph R.
2013-01-01
Science.gov (United States)
Grdina, David J; Murley, Jeffrey S; Miller, Richard C; Mauceri, Helena J; Sutton, Harold G; Li, Jian Jian; Woloschak, Gayle E; Weichselbaum, Ralph R
2013-07-15
Science.gov (United States)
Wise, John H.; Abel, Tom
2011-07-01
13. Directions in Radiation Transport Modelling
Directory of Open Access Journals (Sweden)
P Nicholas Smith
2016-12-01
More exciting advances are on the horizon to increase the power of simulation tools. The advent of high performance computers is allowing bigger, higher fidelity models to be created, if the challenges of parallelization and memory management can be met. 3D whole core transport modelling is becoming possible. Uncertainty quantification is improving with large benefits to be gained from more accurate, less pessimistic estimates of uncertainty. Advanced graphical displays allow the user to assimilate and make sense of the vast amounts of data produced by modern modelling tools. Numerical solvers are being developed that use goal-based adaptivity to adjust the nodalisation of the system to provide the optimum scheme to achieve the user requested accuracy on the results, thus removing the need to perform costly convergence studies in space and angle etc. More use is being made of multi-physics methods in which radiation transport is coupled with other phenomena, such as thermal-hydraulics, structural response, fuel performance and/or chemistry in order to better understand their interplay in reactor cores.
Directory of Open Access Journals (Sweden)
Maxim V Kapralov
Science.gov (United States)
Ouared, Abderrahmane; Montagnon, Emmanuel; Kazemirad, Siavash; Gaboury, Louis; Robidoux, André; Cloutier, Guy
2015-08-01
In remote dynamic elastography, the amplitude of the generated displacement field is directly related to the amplitude of the radiation force. Therefore, displacement improvement for better tissue characterization requires the optimization of the radiation force amplitude by increasing the push duration and/or the excitation amplitude applied on the transducer. The main problem of these approaches is that the Food and Drug Administration (FDA) thresholds for medical applications and transducer limitations may be easily exceeded. In the present study, the effect of the frequency used for the generation of the radiation force on the amplitude of the displacement field was investigated. We found that amplitudes of displacements generated by adapted radiation force sequences were greater than those generated by standard nonadapted ones (i.e., single push acoustic radiation force impulse and supersonic shear imaging). Gains in magnitude were between 20 to 158% for in vitro measurements on agar-gelatin phantoms, and 170 to 336% for ex vivo measurements on a human breast sample, depending on focus depths and attenuations of tested samples. The signal-to-noise ratio was also improved more than 4-fold with adapted sequences. We conclude that frequency adaptation is a complementary technique that is efficient for the optimization of displacement amplitudes. This technique can be used safely to optimize the deposited local acoustic energy without increasing the risk of damaging tissues and transducer elements.
OpenAIRE
Hügli, Heinz; Bur, Alexandre
2009-01-01
Visual attention, defined as the ability of a biological or artificial vision system to rapidly detect potentially relevant parts of a visual scene, provides a general purpose solution for low level feature detection in a vision architecture. Well considered for its universal detection behaviour, the general model of visual attention is suited for any environment but inferior to dedicated feature detectors in more specific environments. The goal of the development presented in this paper is t...
Science.gov (United States)
Zubkova, S M
1996-01-01
The chance to use electromagnetic exposures as active adaptogen and the detecting of adaptive changes following them were objects of our studies. The data of experimental and clinical studies significative the dependence of changes on the functional state of organism were seen. Particular attention is paid to the site of exposure and to the advantages in the action of electromagnetic exposures on areas overlaying the endocrine glands and control centers of central nerve system. In these conditions electromagnetic exposures play a part of trigger initiated natural processes of homeostatic regulation in the organism functional systems. It is shown that the course of electromagnetic exposures in wide frequency range until laser radiation (infrared and red) arises adaptive changes of the regulator systems, of the bioenergetic and the biosynthetic processes in myocardium, liver, brain, thymus and other tissues predetermined genetically and secured the power of the adaptive systems. The cross-adaptation effects underlie the electromagnetic exposures medical action.
Energy Technology Data Exchange (ETDEWEB)
Okuno, Koichi; Hara, Akihisa (Hazama Corp., Tokyo (Japan))
1992-12-01
Science.gov (United States)
Pillon, Yohan; Hopkins, Helen C F; Rigault, Frédéric; Jaffré, Tanguy; Stacy, Elizabeth A
2014-04-01
The causes of the species richness of tropical trees are poorly understood, in particular the roles of ecological factors such as soil composition. The nickel(Ni)-hyperaccumulating tree genus Geissois (Cunoniaceae) from the South-west Pacific was chosen as a model of diversification on different substrates. Here, we investigated the leaf element compositions, spatial distributions and phylogeny of all species of Geissois occurring on New Caledonia. We found that New Caledonian Geissois descended from a single colonist and diversified relatively quickly into 13 species. Species on ultramafic and nonultramafic substrates showed contrasting patterns of leaf element composition and range overlap. Those on nonultramafic substrates were largely sympatric but had distinct leaf element compositions. By contrast, species on ultramafic substrates showed similar leaf element composition, but occurred in many cases exclusively in allopatry. Further, earlier work showed that at least three out of these seven species use different molecules to bind Ni. Geissois qualifies as a cryptic adaptive radiation, and may be the first such example in a lineage of tropical forest trees. Variation in biochemical strategies for coping with both typical and adverse soil conditions may help to explain the diversification and coexistence of tropical forest trees on similar soil types.
Science.gov (United States)
Meier, Joana I.; Marques, David A.; Mwaiko, Salome; Wagner, Catherine E.; Excoffier, Laurent; Seehausen, Ole
2017-01-01
Understanding why some evolutionary lineages generate exceptionally high species diversity is an important goal in evolutionary biology. Haplochromine cichlid fishes of Africa's Lake Victoria region encompass >700 diverse species that all evolved in the last 150,000 years. How this ‘Lake Victoria Region Superflock' could evolve on such rapid timescales is an enduring question. Here, we demonstrate that hybridization between two divergent lineages facilitated this process by providing genetic variation that subsequently became recombined and sorted into many new species. Notably, the hybridization event generated exceptional allelic variation at an opsin gene known to be involved in adaptation and speciation. More generally, differentiation between new species is accentuated around variants that were fixed differences between the parental lineages, and that now appear in many new combinations in the radiation species. We conclude that hybridization between divergent lineages, when coincident with ecological opportunity, may facilitate rapid and extensive adaptive radiation. PMID:28186104
Science.gov (United States)
Fuller, C. R.; Rogers, C. A.; Robertshaw, H. H.
1992-01-01
Recent research is discussed in the area of active structural acoustic control with active/adaptive structures. Progress in the areas of structural acoustics, actuators, sensors, and control approaches is presented. Considerable effort has been given to the interaction of these areas with each other due to the coupled nature of the problem. A discussion is presented on actuators bonded to or embedded in the structure itself. The actuators discussed are piezoceramic actuators and shape memory alloy actuators. The sensors discussed are optical fiber sensors, Nitinol fiber sensors, piezoceramics, and polyvinylidene fluoride sensors. The active control techniques considered are state feedback control techniques and least mean square adaptive algorithms. Results presented show that significant progress has been made towards controlling structurally radiated noise by active/adaptive means applied directly to the structure.
2. "Intelligent Ensemble" Projections of Precipitation and Surface Radiation in Support of Agricultural Climate Change Adaptation
Science.gov (United States)
Taylor, Patrick C.; Baker, Noel C.
2015-01-01
Earth's climate is changing and will continue to change into the foreseeable future. Expected changes in the climatological distribution of precipitation, surface temperature, and surface solar radiation will significantly impact agriculture. Adaptation strategies are, therefore, required to reduce the agricultural impacts of climate change. Climate change projections of precipitation, surface temperature, and surface solar radiation distributions are necessary input for adaption planning studies. These projections are conventionally constructed from an ensemble of climate model simulations (e.g., the Coupled Model Intercomparison Project 5 (CMIP5)) as an equal weighted average, one model one vote. Each climate model, however, represents the array of climate-relevant physical processes with varying degrees of fidelity influencing the projection of individual climate variables differently. Presented here is a new approach, termed the "Intelligent Ensemble, that constructs climate variable projections by weighting each model according to its ability to represent key physical processes, e.g., precipitation probability distribution. This approach provides added value over the equal weighted average method. Physical process metrics applied in the "Intelligent Ensemble" method are created using a combination of NASA and NOAA satellite and surface-based cloud, radiation, temperature, and precipitation data sets. The "Intelligent Ensemble" method is applied to the RCP4.5 and RCP8.5 anthropogenic climate forcing simulations within the CMIP5 archive to develop a set of climate change scenarios for precipitation, temperature, and surface solar radiation in each USDA Farm Resource Region for use in climate change adaptation studies.
OpenAIRE
2007-01-01
The risks of exposure to low dose ionizing radiation (below 100 mSv) are estimated by extrapolating from data obtained after exposure to high dose radiation, using a linear no-threshold model (LNT model). However, the validity of using this dose-response model is controversial because evidence accumulated over the past decade has indicated that living organisms, including humans, respond differently to low dose/low dose-rate radiation than they do to high dose/high dose-rate radiation. In oth...
4. Adaptive Numerical Algorithms in Space Weather Modeling
Science.gov (United States)
Toth, Gabor; vanderHolst, Bart; Sokolov, Igor V.; DeZeeuw, Darren; Gombosi, Tamas I.; Fang, Fang; Manchester, Ward B.; Meng, Xing; Nakib, Dalal; Powell, Kenneth G.; Stout, Quentin F.; Glocer, Alex; Ma, Ying-Juan; Opher, Merav
2010-01-01
Space weather describes the various processes in the Sun-Earth system that present danger to human health and technology. The goal of space weather forecasting is to provide an opportunity to mitigate these negative effects. Physics-based space weather modeling is characterized by disparate temporal and spatial scales as well as by different physics in different domains. A multi-physics system can be modeled by a software framework comprising of several components. Each component corresponds to a physics domain, and each component is represented by one or more numerical models. The publicly available Space Weather Modeling Framework (SWMF) can execute and couple together several components distributed over a parallel machine in a flexible and efficient manner. The framework also allows resolving disparate spatial and temporal scales with independent spatial and temporal discretizations in the various models. Several of the computationally most expensive domains of the framework are modeled by the Block-Adaptive Tree Solar wind Roe Upwind Scheme (BATS-R-US) code that can solve various forms of the magnetohydrodynamics (MHD) equations, including Hall, semi-relativistic, multi-species and multi-fluid MHD, anisotropic pressure, radiative transport and heat conduction. Modeling disparate scales within BATS-R-US is achieved by a block-adaptive mesh both in Cartesian and generalized coordinates. Most recently we have created a new core for BATS-R-US: the Block-Adaptive Tree Library (BATL) that provides a general toolkit for creating, load balancing and message passing in a 1, 2 or 3 dimensional block-adaptive grid. We describe the algorithms of BATL and demonstrate its efficiency and scaling properties for various problems. BATS-R-US uses several time-integration schemes to address multiple time-scales: explicit time stepping with fixed or local time steps, partially steady-state evolution, point-implicit, semi-implicit, explicit/implicit, and fully implicit numerical
Directory of Open Access Journals (Sweden)
Taoran Li
2010-01-01
Full Text Available The purpose of this paper is to evaluate the feasibility and clinical dosimetric benefit of an on-line, that is, with the patient in the treatment position, Adaptive Radiation Therapy (ART system for prostate cancer treatment based on daily cone-beam CT imaging and fast volumetric reoptimization of treatment plans. A fast intensity-modulated radiotherapy (IMRT plan reoptimization algorithm is implemented and evaluated with clinical cases. The quality of these adapted plans is compared to the corresponding new plans generated by an experienced planner using a commercial treatment planning system and also evaluated by an in-house developed tool estimating achievable dose-volume histograms (DVHs based on a database of existing treatment plans. In addition, a clinical implementation scheme for ART is designed and evaluated using clinical cases for its dosimetric qualities and efficiency.
Science.gov (United States)
Chow, Stephanie S; Wilke, Claus O; Ofria, Charles; Lenski, Richard E; Adami, Christoph
2004-07-02
Species richness often peaks at intermediate productivity and decreases as resources become more or less abundant. The mechanisms that produce this pattern are not completely known, but several previous studies have suggested environmental heterogeneity as a cause. In experiments with evolving digital organisms and populations of fixed size, maximum species richness emerges at intermediate productivity, even in a spatially homogeneous environment, owing to frequency-dependent selection to exploit an influx of mixed resources. A diverse pool of limiting resources is sufficient to cause adaptive radiation, which is manifest by the origin and maintenance of phenotypically and phylogenetically distinct groups of organisms.
Science.gov (United States)
Vercauteren, Tom; De Gersem, Werner; Olteanu, Luiza A M; Madani, Indira; Duprez, Fréderic; Berwouts, Dieter; Speleers, Bruno; De Neve, Wilfried
2013-08-07
Development and implementation of chronological and anti-chronological adaptive dose accumulation strategies in adaptive intensity-modulated radiation therapy (IMRT) for head-and-neck cancer. An algorithm based on Newton iterations was implemented to efficiently compute inverse deformation fields (DFs). Four verification steps were performed to ensure a valid dose propagation: intra-cell folding detection finds zero or negative Jacobian determinants in the input DF; inter-cell folding detection is implemented on the resolution of the output DF; a region growing algorithm detects undefined values in the output DF; DF domains can be composed and displayed on the CT data. In 2011, one patient with nonmetastatic head and neck cancer selected from a three phase adaptive DPBN study was used to illustrate the algorithms implemented for adaptive chronological and anti-chronological dose accumulation. The patient received three (18)F-FDG-PET/CTs prior to each treatment phase and one CT after finalizing treatment. Contour propagation and DF generation between two consecutive CTs was performed in Atlas-based autosegmentation (ABAS). Deformable image registration based dose accumulations were performed on CT1 and CT4. Dose propagation was done using combinations of DFs or their inversions. We have implemented a chronological and anti-chronological dose accumulation algorithm based on DF inversion. Algorithms were designed and implemented to detect cell folding.
Science.gov (United States)
Vercauteren, Tom; De Gersem, Werner; Olteanu, Luiza A. M.; Madani, Indira; Duprez, Fréderic; Berwouts, Dieter; Speleers, Bruno; De Neve, Wilfried
2013-08-01
Development and implementation of chronological and anti-chronological adaptive dose accumulation strategies in adaptive intensity-modulated radiation therapy (IMRT) for head-and-neck cancer. An algorithm based on Newton iterations was implemented to efficiently compute inverse deformation fields (DFs). Four verification steps were performed to ensure a valid dose propagation: intra-cell folding detection finds zero or negative Jacobian determinants in the input DF; inter-cell folding detection is implemented on the resolution of the output DF; a region growing algorithm detects undefined values in the output DF; DF domains can be composed and displayed on the CT data. In 2011, one patient with nonmetastatic head and neck cancer selected from a three phase adaptive DPBN study was used to illustrate the algorithms implemented for adaptive chronological and anti-chronological dose accumulation. The patient received three 18F-FDG-PET/CTs prior to each treatment phase and one CT after finalizing treatment. Contour propagation and DF generation between two consecutive CTs was performed in Atlas-based autosegmentation (ABAS). Deformable image registration based dose accumulations were performed on CT1 and CT4. Dose propagation was done using combinations of DFs or their inversions. We have implemented a chronological and anti-chronological dose accumulation algorithm based on DF inversion. Algorithms were designed and implemented to detect cell folding.
9. Novel trophic niches drive variable progress towards ecological speciation within an adaptive radiation of pupfishes.
Science.gov (United States)
Martin, Christopher H; Feinstein, Laura C
2014-04-01
10. 3D Continuum Radiative Transfer. An adaptive grid construction algorithm based on the Monte Carlo method
Science.gov (United States)
Niccolini, G.; Alcolea, J.
Solving the radiative transfer problem is a common problematic to may fields in astrophysics. With the increasing angular resolution of spatial or ground-based telescopes (VLTI, HST) but also with the next decade instruments (NGST, ALMA, ...), astrophysical objects reveal and will certainly reveal complex spatial structures. Consequently, it is necessary to develop numerical tools being able to solve the radiative transfer equation in three dimensions in order to model and interpret these observations. I present a 3D radiative transfer program, using a new method for the construction of an adaptive spatial grid, based on the Monte Claro method. With the help of this tools, one can solve the continuum radiative transfer problem (e.g. a dusty medium), computes the temperature structure of the considered medium and obtain the flux of the object (SED and images).
Science.gov (United States)
Pincheira-Donoso, Daniel; Harvey, Lilly P; Ruta, Marcello
2015-08-07
Adaptive radiation theory posits that ecological opportunity promotes rapid proliferation of phylogenetic and ecological diversity. Given that adaptive radiation proceeds via occupation of available niche space in newly accessed ecological zones, theory predicts that: (i) evolutionary diversification follows an 'early-burst' process, i.e., it accelerates early in the history of a clade (when available niche space facilitates speciation), and subsequently slows down as niche space becomes saturated by new species; and (ii) phylogenetic branching is accompanied by diversification of ecologically relevant phenotypic traits among newly evolving species. Here, we employ macroevolutionary phylogenetic model-selection analyses to address these two predictions about evolutionary diversification using one of the most exceptionally species-rich and ecologically diverse lineages of living vertebrates, the South American lizard genus Liolaemus. Our phylogenetic analyses lend support to a density-dependent lineage diversification model. However, the lineage through-time diversification curve does not provide strong support for an early burst. In contrast, the evolution of phenotypic (body size) relative disparity is high, significantly different from a Brownian model during approximately the last 5 million years of Liolaemus evolution. Model-fitting analyses also reject the 'early-burst' model of phenotypic evolution, and instead favour stabilizing selection (Ornstein-Uhlenbeck, with three peaks identified) as the best model for body size diversification. Finally, diversification rates tend to increase with smaller body size. Liolaemus have diversified under a density-dependent process with slightly pronounced apparent episodic pulses of lineage accumulation, which are compatible with the expected episodic ecological opportunity created by gradual uplifts of the Andes over the last ~25My. We argue that ecological opportunity can be strong and a crucial driver of adaptive
12. Selection towards different adaptive optima drove the early diversification of locomotor phenotypes in the radiation of Neotropical geophagine cichlids.
Science.gov (United States)
Astudillo-Clavijo, Viviana; Arbour, Jessica H; López-Fernández, Hernán
2015-05-01
Science.gov (United States)
Rovatsos, Michail; Altmanová, Marie; Pokorná, Martina; Kratochvíl, Lukáš
2014-07-01
Vertebrates possess diverse sex-determining systems, which differ in evolutionary stability among particular groups. It has been suggested that poikilotherms possess more frequent turnovers of sex chromosomes than homoiotherms, whose effective thermoregulation can prevent the emergence of the sex reversals induced by environmental temperature. Squamate reptiles used to be regarded as a group with an extensive variability in sex determination; however, we document how the rather old radiation of lizards from the genus Anolis, known for exceptional ecomorphological variability, was connected with stability in sex chromosomes. We found that 18 tested species, representing most of the phylogenetic diversity of the genus, share the gene content of their X chromosomes. Furthermore, we discovered homologous sex chromosomes in species of two genera (Sceloporus and Petrosaurus) from the family Phrynosomatidae, serving here as an outgroup to Anolis. We can conclude that the origin of sex chromosomes within iguanas largely predates the Anolis radiation and that the sex chromosomes of iguanas remained conserved for a significant part of their evolutionary history. Next to therian mammals and birds, Anolis lizards therefore represent another adaptively radiated amniote clade with conserved sex chromosomes. We argue that the evolutionary stability of sex-determining systems may reflect an advanced stage of differentiation of sex chromosomes rather than thermoregulation strategy.
Energy Technology Data Exchange (ETDEWEB)
Qin, Yujiao [Medical Physics Graduate Program, Duke University, Durham, North Carolina (United States); Zhang, Fan [Occupational and Environmental Safety Office, Duke University Medical Center, Durham, North Carolina (United States); Yoo, David S.; Kelsey, Chris R. [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Yin, Fang-Fang [Medical Physics Graduate Program, Duke University, Durham, North Carolina (United States); Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Cai, Jing, E-mail: [email protected] [Medical Physics Graduate Program, Duke University, Durham, North Carolina (United States); Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States)
2013-09-01
Science.gov (United States)
Qin, Yujiao; Zhang, Fan; Yoo, David S; Kelsey, Chris R; Yin, Fang-Fang; Cai, Jing
2013-09-01
16. Decoupling of morphological disparity and taxic diversity during the adaptive radiation of anomodont therapsids.
Science.gov (United States)
Ruta, Marcello; Angielczyk, Kenneth D; Fröbisch, Jörg; Benton, Michael J
2013-10-07
Science.gov (United States)
Weir, Jason T; Mursleen, Sara
2013-02-01
Science.gov (United States)
Kibrom, Awet Z; Knight, Kellie A
2015-12-01
19. Adaptive phenotypic plasticity in the Midas cichlid fish pharyngeal jaw and its relevance in adaptive radiation
Directory of Open Access Journals (Sweden)
Salzburger Walter
2011-04-01
Full Text Available Abstract Background Phenotypic evolution and its role in the diversification of organisms is a central topic in evolutionary biology. A neglected factor during the modern evolutionary synthesis, adaptive phenotypic plasticity, more recently attracted the attention of many evolutionary biologists and is now recognized as an important ingredient in both population persistence and diversification. The traits and directions in which an ancestral source population displays phenotypic plasticity might partly determine the trajectories in morphospace, which are accessible for an adaptive radiation, starting from the colonization of a novel environment. In the case of repeated colonizations of similar environments from the same source population this "flexible stem" hypothesis predicts similar phenotypes to arise in repeated subsequent radiations. The Midas Cichlid (Amphilophus spp. in Nicaragua has radiated in parallel in several crater-lakes seeded by populations originating from the Nicaraguan Great Lakes. Here, we tested phenotypic plasticity in the pharyngeal jaw of Midas Cichlids. The pharyngeal jaw apparatus of cichlids, a second set of jaws functionally decoupled from the oral ones, is known to mediate ecological specialization and often differs strongly between sister-species. Results We performed a common garden experiment raising three groups of Midas cichlids on food differing in hardness and calcium content. Analyzing the lower pharyngeal jaw-bones we find significant differences between diet groups qualitatively resembling the differences found between specialized species. Observed differences in pharyngeal jaw expression between groups were attributable to the diet's mechanical resistance, whereas surplus calcium in the diet was not found to be of importance. Conclusions The pharyngeal jaw apparatus of Midas Cichlids can be expressed plastically if stimulated mechanically during feeding. Since this trait is commonly differentiated - among
Science.gov (United States)
Wilson, Gregory P; Evans, Alistair R; Corfe, Ian J; Smits, Peter D; Fortelius, Mikael; Jernvall, Jukka
2012-03-14
The Cretaceous-Paleogene mass extinction approximately 66 million years ago is conventionally thought to have been a turning point in mammalian evolution. Prior to that event and for the first two-thirds of their evolutionary history, mammals were mostly confined to roles as generalized, small-bodied, nocturnal insectivores, presumably under selection pressures from dinosaurs. Release from these pressures, by extinction of non-avian dinosaurs at the Cretaceous-Paleogene boundary, triggered ecological diversification of mammals. Although recent individual fossil discoveries have shown that some mammalian lineages diversified ecologically during the Mesozoic era, comprehensive ecological analyses of mammalian groups crossing the Cretaceous-Paleogene boundary are lacking. Such analyses are needed because diversification analyses of living taxa allow only indirect inferences of past ecosystems. Here we show that in arguably the most evolutionarily successful clade of Mesozoic mammals, the Multituberculata, an adaptive radiation began at least 20 million years before the extinction of non-avian dinosaurs and continued across the Cretaceous-Paleogene boundary. Disparity in dental complexity, which relates to the range of diets, rose sharply in step with generic richness and disparity in body size. Moreover, maximum dental complexity and body size demonstrate an adaptive shift towards increased herbivory. This dietary expansion tracked the ecological rise of angiosperms and suggests that the resources that were available to multituberculates were relatively unaffected by the Cretaceous-Paleogene mass extinction. Taken together, our results indicate that mammals were able to take advantage of new ecological opportunities in the Mesozoic and that at least some of these opportunities persisted through the Cretaceous-Paleogene mass extinction. Similar broad-scale ecomorphological inventories of other radiations may help to constrain the possible causes of mass extinctions.
Science.gov (United States)
Mortazavi, S M J; Motamedifar, M; Namdari, G; Taheri, M; Mortazavi, A R; Shokrpour, N
2014-05-01
2. Adaptation of the black yeast Wangiella dermatitidis to ionizing radiation: molecular and cellular mechanisms.
Directory of Open Access Journals (Sweden)
Kelly L Robertson
Science.gov (United States)
Choi, V W Y; Ng, C Y P; Kong, M K Y; Cheng, S H; Yu, K N
2013-03-01
An adaptive response is a biological response where the exposure of cells or animals to a low priming exposure induces mechanisms that protect the cells or animals against the detrimental effects of a subsequent larger challenging exposure. In realistic environmental situations, living organisms can be exposed to a mixture of stressors, and the resultant effects due to such exposures are referred to as multiple stressor effects. In the present work we demonstrated, via quantification of apoptosis in the embryos, that embryos of the zebrafish (Danio rerio) subjected to a priming exposure provided by one environmental stressor (cadmium in micromolar concentrations) could undergo an adaptive response against a subsequent challenging exposure provided by another environmental stressor (alpha particles). We concluded that zebrafish embryos treated with 1 to 10 μM Cd at 5 h postfertilisation (hpf) for both 1 and 5 h could undergo an adaptive response against subsequent ~4.4 mGy alpha-particle irradiation at 10 hpf, which could be interpreted as an antagonistic multiple stressor effect between Cd and ionising radiation. The zebrafish has become a popular vertebrate model for studying the in vivo response to ionising radiation. As such, our results suggested that multiple stressor effects should be carefully considered for human radiation risk assessment since the risk may be perturbed by another environmental stressor such as a heavy metal.
Science.gov (United States)
Vaughan, Naomi; Lenton, Timothy
2010-05-01
5. Plant adaptive behaviour in hydrological models (Invited)
Science.gov (United States)
van der Ploeg, M. J.; Teuling, R.
2013-12-01
Models that will be able to cope with future precipitation and evaporation regimes need a solid base that describes the essence of the processes involved [1]. Micro-behaviour in the soil-vegetation-atmosphere system may have a large impact on patterns emerging at larger scales. A complicating factor in the micro-behaviour is the constant interaction between vegetation and geology in which water plays a key role. The resilience of the coupled vegetation-soil system critically depends on its sensitivity to environmental changes. As a result of environmental changes vegetation may wither and die, but such environmental changes may also trigger gene adaptation. Constant exposure to environmental stresses, biotic or abiotic, influences plant physiology, gene adaptations, and flexibility in gene adaptation [2-6]. Gene expression as a result of different environmental conditions may profoundly impact drought responses across the same plant species. Differences in response to an environmental stress, has consequences for the way species are currently being treated in models (single plant to global scale). In particular, model parameters that control root water uptake and plant transpiration are generally assumed to be a property of the plant functional type. Assigning plant functional types does not allow for local plant adaptation to be reflected in the model parameters, nor does it allow for correlations that might exist between root parameters and soil type. Models potentially provide a means to link root water uptake and transport to large scale processes (e.g. Rosnay and Polcher 1998, Feddes et al. 2001, Jung 2010), especially when powered with an integrated hydrological, ecological and physiological base. We explore the experimental evidence from natural vegetation to formulate possible alternative modeling concepts. [1] Seibert, J. 2000. Multi-criteria calibration of a conceptual runoff model using a genetic algorithm. Hydrology and Earth System Sciences 4(2): 215
6. Optimization of adaptive radiation therapy in cervical cancer: Solutions for photon and proton therapy
NARCIS (Netherlands)
van de Schoot, A.J.A.J.
2016-01-01
In cervical cancer radiation therapy, an adaptive strategy is required to compensate for interfraction anatomical variations in order to achieve adequate dose delivery. In this thesis, we have aimed at optimizing adaptive radiation therapy in cervical cancer to improve treatment efficiency and
NARCIS (Netherlands)
Jonsson, Knud A.; Fabre, Pierre-Henri; Fritz, Susanne A.; Etienne, Rampal S.; Ricklefs, Robert E.; Jorgensen, Tobias B.; Fjeldsa, Jon; Rahbek, Carsten; Ericson, Per G. P.; Woog, Friederike; Pasquet, Eric; Irestedt, Martin
2012-01-01
Adaptive radiation is the rapid diversification of a single lineage into many species that inhabit a variety of environments or use a variety of resources and differ in traits required to exploit these. Why some lineages undergo adaptive radiation is notwell-understood, but filling unoccupied
8. From dinosaurs to modern bird diversity: extending the time scale of adaptive radiation.
Science.gov (United States)
Moen, Daniel; Morlon, Hélène
2014-05-01
9. Optimization of adaptive radiation therapy in cervical cancer: Solutions for photon and proton therapy
NARCIS (Netherlands)
van de Schoot, A.J.A.J.
2016-01-01
In cervical cancer radiation therapy, an adaptive strategy is required to compensate for interfraction anatomical variations in order to achieve adequate dose delivery. In this thesis, we have aimed at optimizing adaptive radiation therapy in cervical cancer to improve treatment efficiency and reduc
10. Modeling cell dynamics under mobile phone radiation.
Science.gov (United States)
Minelli, Tullio Antonio; Balduzzo, Maurizio; Milone, Francesco Ferro; Nofrate, Valentina
2007-04-01
Perturbations by pulse-modulated microwave radiation from GSM mobile phones on neuron cell membrane gating and calcium oscillations have been suggested as a possible mechanism underlying activation of brain states and electroencephalographic epiphenomena. As the employ of UMTS phones seems to reveal other symptoms, a unified phenomenological framework is needed. In order to explain possible effects of mobile phone radiation on cell oscillations, GSM and UMTS low-frequency envelopes have been detected, recorded and used as input in cell models. Dynamical systems endowed with contiguous regular and chaotic regimes suitable to produce stochastic resonance can both account for the perturbation of the neuro-electrical activity and even for the low intensity of the signal perceived by high sensitive subjects. Neuron models of this kind can be employed as a reductionist hint for the mentioned phenomenology. The Hindmarsh-Rose model exhibits frequency enhancement and regularization phenomena induced by weak GSM and UMTS. More realistic simulations of cell membrane gating and calcium oscillations have been performed with the help of an adaptation of the Chay-Keizer dynamical system. This scheme can explain the suspected subjective sensitivity to mobile phone signals under the thermal threshold, in terms of cell calcium regularity mechanisms. Concerning the two kinds of emission, the stronger occupation of the ELF band of last generation UMTS phones is compensated by lower power emitted.
11. Galactic cosmic radiation environment models
Science.gov (United States)
Badhwar, G. D.; O'Neill, P. M.; Troung, A. G.
2001-02-01
Models of the radiation environment in free space and in near earth orbits are required to estimate the radiation dose to the astronauts for Mars, Space Shuttle, and the International Space Station missions, and to estimate the rate of single event upsets and latch-ups in electronic devices. Accurate knowledge of the environment is critical for the design of optimal shielding during both the cruise phase and for a habitat on Mars or the Moon. Measurements of the energy spectra of galactic cosmic rays (GCR) have been made for nearly four decades. In the last decade, models have been constructed that can predict the energy spectra of any GCR nuclei to an accuracy of better than 25%. Fresh and more accurate measurements have been made in the last year. These measurements can lead to more accurate models. Improvements in these models can be made in determining the local interstellar spectra and in predicting the level of solar modulation. It is the coupling of the two that defines a GCR model. This paper reviews of two of the more widely used models, and a comparison of their predictions with new proton and helium data from the Alpha Magnetic Spectrometer (AMS), and spectra of beryllium to iron in the ~40 to 500 MeV/n acquired by the Advanced Composition Explorer (ACE) during the 1997-98 solar minimum. Regressions equations relating the IMP-8 helium count rate to the solar modulation deceleration parameter calculated using the Climax neutron monitor rate have been developed and may lead to improvements in the predictive capacity of the models. .
Science.gov (United States)
Guidi, Gabriele; Maffei, Nicola; Vecchi, Claudio; Gottardi, Giovanni; Ciarmatori, Alberto; Mistretta, Grazia Maria; Mazzeo, Ercole; Giacobazzi, Patrizia; Lohr, Frank; Costi, Tiziana
2017-06-01
Science.gov (United States)
Rosen, A. L.; Krumholz, M. R.; Oishi, J. S.; Lee, A. T.; Klein, R. I.
2017-02-01
We present a highly-parallel multi-frequency hybrid radiation hydrodynamics algorithm that combines a spatially-adaptive long characteristics method for the radiation field from point sources with a moment method that handles the diffuse radiation field produced by a volume-filling fluid. Our Hybrid Adaptive Ray-Moment Method (HARM2) operates on patch-based adaptive grids, is compatible with asynchronous time stepping, and works with any moment method. In comparison to previous long characteristics methods, we have greatly improved the parallel performance of the adaptive long-characteristics method by developing a new completely asynchronous and non-blocking communication algorithm. As a result of this improvement, our implementation achieves near-perfect scaling up to O (103) processors on distributed memory machines. We present a series of tests to demonstrate the accuracy and performance of the method.
14. Hybrid Adaptive Ray-Moment Method (HARM$^2$): A Highly Parallel Method for Radiation Hydrodynamics on Adaptive Grids
CERN Document Server
Rosen, Anna L; Oishi, Jeffrey S; Lee, Aaron T; Klein, Richard I
2016-01-01
We present a highly-parallel multi-frequency hybrid radiation hydrodynamics algorithm that combines a spatially-adaptive long characteristics method for the radiation field from point sources with a moment method that handles the diffuse radiation field produced by a volume-filling fluid. Our Hybrid Adaptive Ray-Moment Method (HARM$^2$) operates on patch-based adaptive grids, is compatible with asynchronous time stepping, and works with any moment method. In comparison to previous long characteristics methods, we have greatly improved the parallel performance of the adaptive long-characteristics method by developing a new completely asynchronous and non-blocking communication algorithm. As a result of this improvement, our implementation achieves near-perfect scaling up to $\\mathcal{O}(10^3)$ processors on distributed memory machines. We present a series of tests to demonstrate the accuracy and performance of the method.
15. A diversified portfolio model of adaptability.
Science.gov (United States)
Chandra, Siddharth; Leong, Frederick T L
2016-12-01
16. Adaptive introgression from distant Caribbean islands contributed to the diversification of a microendemic adaptive radiation of trophic specialist pupfishes.
Science.gov (United States)
Richards, Emilie J; Martin, Christopher H
2017-08-01
17. Adaptive introgression from distant Caribbean islands contributed to the diversification of a microendemic adaptive radiation of trophic specialist pupfishes.
Directory of Open Access Journals (Sweden)
Emilie J Richards
2017-08-01
CERN Document Server
González, Matthias; Commerçon, Benoît; Masson, Jacques
2015-01-01
Radiative transfer plays a key role in the star formation process. Due to a high computational cost, radiation-hydrodynamics simulations performed up to now have mainly been carried out in the grey approximation. In recent years, multi-frequency radiation-hydrodynamics models have started to emerge, in an attempt to better account for the large variations of opacities as a function of frequency. We wish to develop an efficient multigroup algorithm for the adaptive mesh refinement code RAMSES which is suited to heavy proto-stellar collapse calculations. Due to prohibitive timestep constraints of an explicit radiative transfer method, we constructed a time-implicit solver based on a stabilised bi-conjugate gradient algorithm, and implemented it in RAMSES under the flux-limited diffusion approximation. We present a series of tests which demonstrate the high performance of our scheme in dealing with frequency-dependent radiation-hydrodynamic flows. We also present a preliminary simulation of a three-dimensional p...
19. Optical solar energy adaptations and radiative temperature control of green leaves and tree barks
Energy Technology Data Exchange (ETDEWEB)
Henrion, Wolfgang; Tributsch, Helmut [Department of Si-Photovoltaik and Solare Energetik, Hahn-Meitner-Institut Berlin, 14109 Berlin (Germany)
2009-01-15
Trees have adapted to keep leaves and barks cool in sunshine and can serve as interesting bionic model systems for radiative cooling. Silicon solar cells, on the other hand, loose up to one third of their energy efficiency due to heating in intensive sunshine. It is shown that green leaves minimize absorption of useful radiation and allow efficient infrared thermal emission. Since elevated temperatures are detrimental for tensile water flow in the Xylem tissue below barks, the optical properties of barks should also have evolved so as to avoid excessive heating. This was tested by performing optical studies with tree bark samples from representative trees. It was found that tree barks have optimized their reflection of incoming sunlight between 0.7 and 2 {mu}m. This is approximately the optical window in which solar light is transmitted and reflected by green vegetation. Simultaneously, the tree bark is highly absorbing and thus radiation emitting between 6 and 10 {mu}m. These two properties, mainly provided by tannins, create optimal conditions for radiative temperature control. In addition, tannins seem to have adopted a function as mediators for excitation energy towards photo-antioxidative activity for control of radiation damage. The results obtained are used to discuss challenges for future solar cell optimization. (author)
20. Radiation Belt and Plasma Model Requirements
Science.gov (United States)
Barth, Janet L.
2005-01-01
Contents include the following: Radiation belt and plasma model environment. Environment hazards for systems and humans. Need for new models. How models are used. Model requirements. How can space weather community help?
1. Unobtrusive user modeling for adaptive hypermedia
NARCIS (Netherlands)
Holz, H.J.; Hofmann, K.; Reed, C.; Uchyigit, G.; Ma, M.Y.
2008-01-01
We propose a technique for user modeling in Adaptive Hypermedia (AH) that is unobtrusive at both the level of observable behavior and that of cognition. Unobtrusive user modeling is complementary to transparent user modeling. Unobtrusive user modeling induces user models appropriate for Educational
2. Studies of adaptive response and mutation induction in MCF-10A cells following exposure to chronic or acute ionizing radiation.
Science.gov (United States)
Manesh, Sara Shakeri; Sangsuwan, Traimate; Wojcik, Andrzej; Haghdoost, Siamak
2015-10-01
3. [The model of adaptive primary image processing].
Science.gov (United States)
Dudkin, K N; Mironov, S V; Dudkin, A K; Chikhman, V N
1998-07-01
A computer model of adaptive segmentation of the 2D visual objects was developed. Primary image descriptions are realised via spatial frequency filters and feature detectors performing as self-organised mechanisms. Simulation of the control processes related to attention, lateral, frequency-selective and cross-orientation inhibition, determines the adaptive image processing.
4. Multiple models adaptive feedforward decoupling controller
Institute of Scientific and Technical Information of China (English)
Wang Xin; Li Shaoyuan; Wang Zhongjie
2005-01-01
When the parameters of the system change abruptly, a new multivariable adaptive feedforward decoupling controller using multiple models is presented to improve the transient response. The system models are composed of multiple fixed models, one free-running adaptive model and one re-initialized adaptive model. The fixed models are used to provide initial control to the process. The re-initialized adaptive model can be reinitialized as the selected model to improve the adaptation speed. The free-running adaptive controller is added to guarantee the overall system stability. At each instant, the best system model is selected according to the switching index and the corresponding controller is designed. During the controller design, the interaction is viewed as the measurable disturbance and eliminated by the choice of the weighting polynomial matrix. It not only eliminates the steady-state error but also decouples the system dynamically. The global convergence is obtained and several simulation examples are presented to illustrate the effectiveness of the proposed controller.
Science.gov (United States)
Deng, Shan; Liu, Xu; Lu, Heming; Huang, Huixian; Shu, Liuyang; Jiang, Hailan; Cheng, Jinjian; Peng, Luxing; Pang, Qiang; Gu, Junzhao; Qin, Jian; Lu, Zhiping; Mo, Ying; Wu, Danling; Wei, Yinglin
2017-01-01
Science.gov (United States)
Mollenhauer, Hannes; Remmler, Paul; Schuhmann, Gudrun; Lausch, Angela; Merbach, Ines; Assing, Martin; Mollenhauer, Olaf; Dietrich, Peter; Bumberger, Jan
2016-04-01
Nutrients such as nitrogen are playing a key role in the plant life cycle. They are much needed for chlorophyll production and other plant cell components. Therefore, the crop yield is strongly affected by plant nutrient status. Due to the spatial and temporal variability of soil characteristics or swaying agricultural inputs the plant development varies within a field. Thus, the determination of these fluctuations in the plant development is valuable for a detection of stress conditions and optimization of fertilisation due to its high environmental and economic impact. Plant parameters play crucial roles in plant growth estimation and prediction since they are used as indicators of plant performance. Especially indices derived out of remote sensing techniques provide quantitative information about agricultural crops instantaneously, and above all, non-destructively. Due to the specific absorption of certain plant pigments, a characteristic spectral signature can be seen in the visible and IR part of the electromagnetic spectrum, known as narrow-band peaks. In an analogous manner, the presence and concentration of different nutrients cause a characteristic spectral signature. To this end, an adequate remote sensing monitoring concept is needed, considering heterogeneity and dynamic of the plant population and economical aspects. This work will present the development and field investigations of an inexpensive multichannel radiation sensor to observe the incoming and reflected specific parts or rather distinct wavelengths of the solar light spectrum on the crop and facilitate the determination of different plant indices. Based on the selected sensor wavelengths, the sensing device allows the detection of specific parameters, e.g. plant vitality, chlorophyll content or nitrogen content. Besides the improvement of the sensor characteristic, the simple wavelength adaption, and the price-performance ratio, the achievement of appropriate energy efficiency as well as a
7. Preliminary survey on site-adaptation techniques for satellite-derived and reanalysis solar radiation datasets
Energy Technology Data Exchange (ETDEWEB)
Polo, J.; Wilbert, S.; Ruiz-Arias, J. A.; Meyer, R.; Gueymard, C.; Súri, M.; Martín, L.; Mieslinger, T.; Blanc, P.; Grant, I.; Boland, J.; Ineichen, P.; Remund, J.; Escobar, R.; Troccoli, A.; Sengupta, M.; Nielsen, K. P.; Renne, D.; Geuder, N.; Cebecauer, T.
2016-07-01
At any site, the bankability of a projected solar power plant largely depends on the accuracy and general quality of the solar radiation data generated during the solar resource assessment phase. The term 'site adaptation' has recently started to be used in the framework of solar energy projects to refer to the improvement that can be achieved in satellite-derived solar irradiance and model data when short-term local ground measurements are used to correct systematic errors and bias in the original dataset. This contribution presents a preliminary survey of different possible techniques that can improve long-term satellite-derived and model-derived solar radiation data through the use of short-term on-site ground measurements. The possible approaches that are reported here may be applied in different ways, depending on the origin and characteristics of the uncertainties in the modeled data. This work, which is the first step of a forthcoming in-depth assessment of methodologies for site adaptation, has been done within the framework of the International Energy Agency Solar Heating and Cooling Programme Task 46 'Solar Resource Assessment and Forecasting.'
8. From dinosaurs to modern bird diversity: extending the time scale of adaptive radiation.
Directory of Open Access Journals (Sweden)
Daniel Moen
2014-05-01
9. Positive diversifying selection is a pervasive adaptive force throughout the Drosophila radiation
DEFF Research Database (Denmark)
Cicconardi, Francesco; Marcatili, Paolo; Arthofer, Wolfgang
2017-01-01
of the most important systems to study adaptive radiation. In this study, we performed a genome-wide analysis of positive diversifying selection on more than 2000 single-copy orthologous groups in 25 species using a recent method of increased accuracy for detecting positive diversifying selection. Adopting...... the Drosophila radiation. Acting on the same biological processes via different routes, positive diversifying selection has promoted diversity of functions and adaptive divergence....
10. Radiative and dynamical modeling of Jupiter's atmosphere
Science.gov (United States)
Guerlet, Sandrine; Spiga, Aymeric
2016-04-01
Jupiter's atmosphere harbours a rich meteorology, with alternate westward and eastward zonal jets, waves signatures and long-living storms. Recent ground-based and spacecraft measurements have also revealed a rich stratospheric dynamics, with the observation of thermal signatures of planetary waves, puzzling meridional distribution of hydrocarbons at odds with predictions of photochemical models, and a periodic equatorial oscillation analogous to the Earth's quasi-biennal oscillation and Saturn's equatorial oscillation. These recent observations, along with the many unanswered questions (What drives and maintain the equatorial oscillations? How important is the seasonal forcing compared to the influence of internal heat? What is the large-scale stratospheric circulation of these giant planets?) motivated us to develop a complete 3D General Circulation Model (GCM) of Saturn and Jupiter. We aim at exploring the large-scale circulation, seasonal variability, and wave activity from the troposphere to the stratosphere of these giant planets. We will briefly present how we adapted our existing Saturn GCM to Jupiter. One of the main change is the addition of a stratospheric haze layer made of fractal aggregates in the auroral regions (poleward of 45S and 30N). This haze layer has a significant radiative impact by modifying the temperature up to +/- 15K in the middle stratosphere. We will then describe the results of radiative-convective simulations and how they compare to recent Cassini and ground-based temperature measurements. These simulations reproduce surprisingly well some of the observed thermal vertical and meridional gradients, but several important mismatches at low and high latitudes suggest that dynamics also plays an important role in shaping the temperature field. Finally, we will present full GCM simulations and discuss the main resulting features (waves and instabilities). We will also and discuss the impact of the choice of spatial resolution and
11. Adaptation of the microdosimetric kinetic model to hypoxia
Science.gov (United States)
Bopp, C.; Hirayama, R.; Inaniwa, T.; Kitagawa, A.; Matsufuji, N.; Noda, K.
2016-11-01
Ion beams present a potential advantage in terms of treatment of lesions with hypoxic regions. In order to use this potential, it is important to accurately model the cell survival of oxic as well as hypoxic cells. In this work, an adaptation of the microdosimetric kinetic (MK) model making it possible to account for cell hypoxia is presented. The adaptation relies on the modification of damage quantity (double strand breaks and more complex lesions) due to the radiation. Model parameters such as domain size and nucleus size are then adapted through a fitting procedure. We applied this approach to two cell lines, HSG and V79 for helium, carbon and neon ions. A similar behaviour of the parameters was found for the two cell lines, namely a reduction of the domain size and an increase in the sensitive nuclear volume of hypoxic cells compared to those of oxic cells. In terms of oxygen enhancement ratio (OER), the experimental data behaviour can be reproduced, including dependence on particle type at the same linear energy transfer (LET). Errors on the cell survival prediction are of the same order of magnitude than for the original MK model. Our adaptation makes it possible to account for hypoxia without modelling the OER as a function of the LET of the particles, but directly accounting for hypoxic cell survival data.
12. A Physical Model of Electron Radiation Belts of Saturn
Science.gov (United States)
Lorenzato, L.; Sicard-Piet, A.; Bourdarie, S.
2012-04-01
13. Radiation Hydrodynamics using Characteristics on Adaptive Decomposed Domains for Massively Parallel Star Formation Simulations
CERN Document Server
Buntemeyer, Lars; Peters, Thomas; Klassen, Mikhail; Pudritz, Ralph E
2015-01-01
We present an algorithm for solving the radiative transfer problem on massively parallel computers using adaptive mesh refinement and domain decomposition. The solver is based on the method of characteristics which requires an adaptive raytracer that integrates the equation of radiative transfer. The radiation field is split into local and global components which are handled separately to overcome the non-locality problem. The solver is implemented in the framework of the magneto-hydrodynamics code FLASH and is coupled by an operator splitting step. The goal is the study of radiation in the context of star formation simulations with a focus on early disc formation and evolution. This requires a proper treatment of radiation physics that covers both the optically thin as well as the optically thick regimes and the transition region in particular. We successfully show the accuracy and feasibility of our method in a series of standard radiative transfer problems and two 3D collapse simulations resembling the ear...
Science.gov (United States)
Lu, Tao
2017-01-01
15. A new approach to adaptive data models
Directory of Open Access Journals (Sweden)
Ion LUNGU
2016-12-01
Full Text Available Over the last decade, there has been a substantial increase in the volume and complexity of data we collect, store and process. We are now aware of the increasing demand for real time data processing in every continuous business process that evolves within the organization. We witness a shift from a traditional static data approach to a more adaptive model approach. This article aims to extend understanding in the field of data models used in information systems by examining how an adaptive data model approach for managing business processes can help organizations accommodate on the fly and build dynamic capabilities to react in a dynamic environment.
Energy Technology Data Exchange (ETDEWEB)
Balenzategui, J. L. [Ciemat. Madrid (Spain)
2000-07-01
This document shows the result of an exhaustive study about the theoretical and numerical models available in the literature about solar radiation modelling. The purpose of this study is to develop or adapt mathematical models describing the solar radiation specifically for Spain locations as well as to create computer tools able to support the labour of researchers or engineers needing solar radiation data to solve or improve the technical or energetic performance of solar systems. As results of this study and revision, a C library (SRADLIB) is presented as a key for the compilation of the mathematical models from different authors, for the comparison among the different approaches and for its application in computer programs. Different topics related to solar radiation and its modelling are first discussed, including the assumptions and conventions adopted and describing the most accepted and used current state-of-the-art models. some typical problems in the numerical calculation of radiation values are also posed with the proposed solution. The document includes next a complete reference of the developed functions, with many examples of application and calculus. (Author) 24 refs.
17. Graphical Models and Computerized Adaptive Testing.
Science.gov (United States)
Mislevy, Robert J.; Almond, Russell G.
This paper synthesizes ideas from the fields of graphical modeling and education testing, particularly item response theory (IRT) applied to computerized adaptive testing (CAT). Graphical modeling can offer IRT a language for describing multifaceted skills and knowledge, and disentangling evidence from complex performances. IRT-CAT can offer…
Energy Technology Data Exchange (ETDEWEB)
Mothersill, Carmel [Medical Physics and Applied Radiation Sciences Unit, McMaster University, Hamilton, Ont., L8S 4K1 (Canada)]. E-mail: [email protected]; Seymour, Colin [Medical Physics and Applied Radiation Sciences Unit, McMaster University, Hamilton, Ont., L8S 4K1 (Canada)]. E-mail: [email protected]
2004-12-02
Our current knowledge of the mechanisms underlying the induction of bystander effects by low doses of high or low LET ionizing radiation is reviewed. The question of what actually constitutes a protective effect is discussed in the context of adaptive (often referred to as hormetic or protective) responses. Finally the review considers critically, how bystander effects may be related to observed adaptive responses or other seemingly protective effects of low doses exposures. Bystander effects induce responses at the tissue level, which are similar to generalized stress responses. Most of the work involving low LET radiation exposure discussed in the existing literature measures a death response. Since many cell populations carry damaged cells without being exposed to radiation (so-called 'background damage'), it is possible that low doses exposures cause removal of cells carrying potentially problematic lesions, prior to exposure to radiation. This mechanism could lead to the production of 'U-shaped' or hormetic dose-response curves. The level of adverse, adaptive or apparently beneficial response will be related to the background damage carried by the original cell population, the level of organization at which damage or harm are scored and the precise definition of 'harm'. This model may be important when attempting to predict the consequences of mixed exposures involving low doses of radiation and other environmental stressors.
19. Hybrid Surface Mesh Adaptation for Climate Modeling
Institute of Scientific and Technical Information of China (English)
Ahmed Khamayseh; Valmor de Almeida; Glen Hansen
2008-01-01
Solution-driven mesh adaptation is becoming quite popular for spatial error control in the numerical simulation of complex computational physics applications, such as climate modeling. Typically, spatial adaptation is achieved by element subdivision (h adaptation) with a primary goal of resolving the local length scales of interest. A second, lesspopular method of spatial adaptivity is called "mesh motion" (r adaptation); the smooth repositioning of mesh node points aimed at resizing existing elements to capture the local length scales. This paper proposes an adaptation method based on a combination of both element subdivision and node point repositioning (rh adaptation). By combining these two methods using the notion of a mobility function, the proposed approach seeks to increase the flexibility and extensibility of mesh motion algorithms while providing a somewhat smoother transition between refined regions than is pro-duced by element subdivision alone. Further, in an attempt to support the requirements of a very general class of climate simulation applications, the proposed method is de-signed to accommodate unstructured, polygonal mesh topologies in addition to the most popular mesh types.
20. Learning to speciate: The biased learning of mate preferences promotes adaptive radiation.
Science.gov (United States)
Gilman, R Tucker; Kozak, Genevieve M
2015-11-01
1. Toward a general theory of adaptive radiation: insights from microbial experimental evolution.
Science.gov (United States)
Kassen, Rees
2009-06-01
2. Species ecological similarity modulates the importance of colonization history for adaptive radiation.
Science.gov (United States)
Tan, Jiaqi; Yang, Xian; Jiang, Lin
2017-06-01
Adaptive radiation is an important evolutionary process, through which a single ancestral lineage rapidly gives rise to multiple newly formed lineages that specialize in different niches. In the first-arrival hypothesis, David Lack emphasized the importance of species colonization history for adaptive radiation, suggesting that the earlier arrival of a diversifying species would allow it to radiate to a greater extent. Here, we report on the first rigorous experimental test of this hypothesis, using the rapidly evolving bacterium Pseudomonas fluorescens SBW25 and six different bacterial competitors. We show that the earlier arrival of P. fluorescens facilitated its diversification. Nevertheless, significant effects of colonization history, which led to alternative diversification trajectories, were observed only when the competitors shared similar niche and competitive fitness with P. fluorescens. These results highlight the important role of species colonization history, modified by their ecological differences, for adaptive radiation. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.
Institute of Scientific and Technical Information of China (English)
ZHANG Weibo; LI Jun; YAN Jianrong
2006-01-01
The key to carry out ICAD technology is to establish the knowledge-based and wide rang of domains-covered product model. This paper put out a knowledge-based methodology of adaptive modeling. It is under the Ontology mind, using the Object-Oriented technology and being a knowledge-based model framework. It involves the diverse domains in product design and realizes the multi-domain modeling, embedding the relative information including standards, regulars and expert experience. To test the feasibility of the methodology, the research bonds of the automotive diaphragm spring clutch design and an adaptive clutch design model is established, using the knowledge-based modeling language-AML.
4. The interaction of sexually and naturally selected traits in the adaptive radiations of cichlid fishes.
Science.gov (United States)
Salzburger, Walter
2009-01-01
The question of how genetic variation translates into organismal diversity has puzzled biologists for decades. Despite recent advances in evolutionary and developmental genetics, the mechanisms that underlie adaptation, diversification and evolutionary innovation remain largely unknown. The exceptionally diverse species flocks of cichlid fishes are textbook examples of adaptive radiation and explosive speciation and emerge as powerful model systems to study the genetic basis of animal diversification. East Africa's hundreds of endemic cichlid species are akin to a natural mutagenesis screen and differ greatly not only in ecologically relevant (hence naturally selected) characters such as mouth morphology and body shape, but also in sexually selected traits such as coloration. One of the most fascinating aspects of cichlid evolution is the frequent occurrence of evolutionary parallelisms, which has led to the question whether selection alone is sufficient to produce these parallel morphologies, or whether a developmental or genetic bias has influenced the direction of diversification. Here, I review fitness-relevant traits that could be responsible for the cichlids' evolutionary success and assess whether these were shaped by sexual or natural selection. I then focus on the interaction and the relative importance of sexual vs. natural selection in cichlid evolution. Finally, I discuss what is currently known about the genes underlying the morphogenesis of adaptively relevant traits and highlight the importance of the forthcoming cichlid genomes in the quest of the genetic basis of diversification in this group.
Science.gov (United States)
Sannino, Anna; Sarti, Maurizio; Reddy, Siddharth B; Prihoda, Thomas J; Vijayalaxmi; Scarfì, Maria Rosaria
2009-06-01
6. Niche evolution and adaptive radiation: Testing the order of trait divergence
Science.gov (United States)
Ackerly, D.D.; Schwilk, D.W.; Webb, C.O.
2006-01-01
In the course of an adaptive radiation, the evolution of niche parameters is of particular interest for understanding modes of speciation and the consequences for coexistence of related species within communities. We pose a general question: In the course of an evolutionary radiation, do traits related to within-community niche differences (?? niche) evolve before or after differentiation of macrohabitat affinity or climatic tolerances (?? niche)? Here we introduce a new test to address this question, based on a modification of the method of independent contrasts. The divergence order test (DOT) is based on the average age of the nodes on a tree, weighted by the absolute magnitude of the contrast at each node for a particular trait. The comparison of these weighted averages reveals whether large divergences for one trait have occurred earlier or later in the course of diversification, relative to a second trait; significance is determined by bootstrapping from maximum-likelihood ancestral state reconstructions. The method is applied to the evolution of Ceanothus, a woody plant group in California, in which co-occurring species exhibit significant differences in a key leaf trait (specific leaf area) associated with contrasting physiological and life history strategies. Co-occurring species differ more for this trait than expected under a null model of community assembly. This ?? niche difference evolved early in the divergence of two major subclades within Ceanothus, whereas climatic distributions (?? niche traits) diversified later within each of the subclades. However, rapid evolution of climate parameters makes inferences of early divergence events highly uncertain, and differentiation of the ?? niche might have taken place throughout the evolution of the group, without leaving a clear phylogenetic signal. Similar patterns observed in several plant and animal groups suggest that early divergence of ?? niche traits might be a common feature of niche evolution in
7. The dynamic radiation environment assimilation model (DREAM)
Energy Technology Data Exchange (ETDEWEB)
Reeves, Geoffrey D [Los Alamos National Laboratory; Koller, Josef [Los Alamos National Laboratory; Tokar, Robert L [Los Alamos National Laboratory; Chen, Yue [Los Alamos National Laboratory; Henderson, Michael G [Los Alamos National Laboratory; Friedel, Reiner H [Los Alamos National Laboratory
2010-01-01
The Dynamic Radiation Environment Assimilation Model (DREAM) is a 3-year effort sponsored by the US Department of Energy to provide global, retrospective, or real-time specification of the natural and potential nuclear radiation environments. The DREAM model uses Kalman filtering techniques that combine the strengths of new physical models of the radiation belts with electron observations from long-term satellite systems such as GPS and geosynchronous systems. DREAM includes a physics model for the production and long-term evolution of artificial radiation belts from high altitude nuclear explosions. DREAM has been validated against satellites in arbitrary orbits and consistently produces more accurate results than existing models. Tools for user-specific applications and graphical displays are in beta testing and a real-time version of DREAM has been in continuous operation since November 2009.
8. Hybrid adaptive control of a dragonfly model
Science.gov (United States)
Couceiro, Micael S.; Ferreira, Nuno M. F.; Machado, J. A. Tenreiro
2012-02-01
Dragonflies show unique and superior flight performances than most of other insect species and birds. They are equipped with two pairs of independently controlled wings granting an unmatchable flying performance and robustness. In this paper, it is presented an adaptive scheme controlling a nonlinear model inspired in a dragonfly-like robot. It is proposed a hybrid adaptive ( HA) law for adjusting the parameters analyzing the tracking error. At the current stage of the project it is considered essential the development of computational simulation models based in the dynamics to test whether strategies or algorithms of control, parts of the system (such as different wing configurations, tail) as well as the complete system. The performance analysis proves the superiority of the HA law over the direct adaptive ( DA) method in terms of faster and improved tracking and parameter convergence.
9. Adaptive regression for modeling nonlinear relationships
CERN Document Server
Knafl, George J
2016-01-01
This book presents methods for investigating whether relationships are linear or nonlinear and for adaptively fitting appropriate models when they are nonlinear. Data analysts will learn how to incorporate nonlinearity in one or more predictor variables into regression models for different types of outcome variables. Such nonlinear dependence is often not considered in applied research, yet nonlinear relationships are common and so need to be addressed. A standard linear analysis can produce misleading conclusions, while a nonlinear analysis can provide novel insights into data, not otherwise possible. A variety of examples of the benefits of modeling nonlinear relationships are presented throughout the book. Methods are covered using what are called fractional polynomials based on real-valued power transformations of primary predictor variables combined with model selection based on likelihood cross-validation. The book covers how to formulate and conduct such adaptive fractional polynomial modeling in the s...
Science.gov (United States)
Nevado, Bruno; Atchison, Guy W.; Hughes, Colin E.; Filatov, Dmitry A.
2016-01-01
The evolutionary processes that drive rapid species diversification are poorly understood. In particular, it is unclear whether Darwinian adaptation or non-adaptive processes are the primary drivers of explosive species diversifications. Here we show that repeated rapid radiations within New World lupins (Lupinus, Leguminosae) were underpinned by a major increase in the frequency of adaptation acting on coding and regulatory changes genome-wide. This contrasts with far less frequent adaptation in genomes of slowly diversifying lupins and all other plant genera analysed. Furthermore, widespread shifts in optimal gene expression coincided with shifts to high rates of diversification and evolution of perenniality, a putative key adaptation trait thought to have triggered the evolutionary radiations in New World lupins. Our results reconcile long-standing debate about the relative importance of protein-coding and regulatory evolution, and represent the first unambiguous evidence for the rapid onset of lineage- and genome-wide accelerated Darwinian evolution during rapid species diversification. PMID:27498896
11. An explanatory model of underwater adaptation
Directory of Open Access Journals (Sweden)
Joaquín Colodro
Full Text Available The underwater environment is an extreme environment that requires a process of human adaptation with specific psychophysiological demands to ensure survival and productive activity. From the standpoint of existing models of intelligence, personality and performance, in this explanatory study we have analyzed the contribution of individual differences in explaining the adaptation of military personnel in a stressful environment. Structural equation analysis was employed to verify a model representing the direct effects of psychological variables on individual adaptation to an adverse environment, and we have been able to confirm, during basic military diving courses, the structural relationships among these variables and their ability to predict a third of the variance of a criterion that has been studied very little to date. In this way, we have confirmed in a sample of professionals (N = 575 the direct relationship of emotional adjustment, conscientiousness and general mental ability with underwater adaptation, as well as the inverse relationship of emotional reactivity. These constructs are the psychological basis for working under water, contributing to an improved adaptation to this environment and promoting risk prevention and safety in diving activities.
12. Semantic models for adaptive interactive systems
CERN Document Server
Hussein, Tim; Lukosch, Stephan; Ziegler, Jürgen; Calvary, Gaëlle
2013-01-01
Providing insights into methodologies for designing adaptive systems based on semantic data, and introducing semantic models that can be used for building interactive systems, this book showcases many of the applications made possible by the use of semantic models.Ontologies may enhance the functional coverage of an interactive system as well as its visualization and interaction capabilities in various ways. Semantic models can also contribute to bridging gaps; for example, between user models, context-aware interfaces, and model-driven UI generation. There is considerable potential for using
13. Error estimation and adaptive chemical transport modeling
Directory of Open Access Journals (Sweden)
Malte Braack
2014-09-01
Full Text Available We present a numerical method to use several chemical transport models of increasing accuracy and complexity in an adaptive way. In largest parts of the domain, a simplified chemical model may be used, whereas in certain regions a more complex model is needed for accuracy reasons. A mathematically derived error estimator measures the modeling error and provides information where to use more accurate models. The error is measured in terms of output functionals. Therefore, one has to consider adjoint problems which carry sensitivity information. This concept is demonstrated by means of ozone formation and pollution emission.
14. Modeling and (adaptive) control of greenhouse climates
NARCIS (Netherlands)
Udink ten Cate, A.J.
1983-01-01
The material presented in this thesis can be grouped around four themes, system concepts, modeling, control and adaptive control. In this summary these themes will be treated separately.
System concepts
In Chapters 1 and 2 an overview of the problem formulation
15. Modelling and (adaptive) control of greenhouse climates
NARCIS (Netherlands)
Udink ten Cate, A.J.
1983-01-01
The material presented in this thesis can be grouped around four themes, system concepts, modeling, control and adaptive control. In this summary these themes will be treated separately.System conceptsIn Chapters 1 and 2 an overview of the problem formulation is presented. It is suggested that there
16. Impurity radiation in DEMO systems modelling
Energy Technology Data Exchange (ETDEWEB)
Lux, H., E-mail: [email protected] [CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Kemp, R.; Ward, D.J. [CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Sertoli, M. [Max-Planck-Institut für Plasma Physik, D-85748 Garching (Germany)
2015-12-15
Highlights: • Solving the exhaust problem is crucial for DEMO. • Here, we discuss the new impurity radiation model in the systems code PROCESS. • Furthermore, we assess its effect on DEMO design. • More appropriate scalings will significantly enhance predictions for DEMO. • The controllability of highly radiative scenarios remains to be shown. - Abstract: For fusion reactors with ITER divertor technology, it will be imperative to significantly reduce the heat flux into the divertor e.g. by seeded impurity radiation. This has to be done without affecting the accessibility of a high performance scenario. To assess the implications of seeded plasma impurities on DEMO design, we have developed an impurity radiation model for radiation inside the separatrix. Evaluating the validity of our model, we find the assumption of a local ionisation equilibrium to be appropriate for our purposes and the assumption of flat impurity profiles – even though not satisfactory – to represent the best currently possible. Benchmarking our model against other codes highlights the need to use up to date atomic loss function data. From the impurity radiation perspective, the main uncertainties in current DEMO design stem from the lack of confinement and L-H-threshold scalings that can be robustly extrapolated to highly radiative DEMO scenarios as well as the lack of appropriate models for the power flow from the separatrix into the divertor that include radiation in the scrape off layer. Despite these uncertainties in the model we can exclude that significant fuel dilution through seeded impurities (with Z ≥ Z{sub Ar}) will be an issue for DEMO, but the controllability of highly radiative scenarios still needs to be coherently shown.
17. Application of Improved Radiation Modeling to General Circulation Models
Energy Technology Data Exchange (ETDEWEB)
Michael J Iacono
2011-04-07
18. Adaptive Modeling for Security Infrastructure Fault Response
Institute of Scientific and Technical Information of China (English)
CUI Zhong-jie; YAO Shu-ping; HU Chang-zhen
2008-01-01
Based on the analysis of inherent limitations in existing security response decision-making systems, a dynamic adaptive model of fault response is presented. Several security fault levels were founded, which comprise the basic level, equipment level and mechanism level. Fault damage cost is calculated using the analytic hierarchy process. Meanwhile, the model evaluates the impact of different responses upon fault repair and normal operation. Response operation cost and response negative cost are introduced through quantitative calculation. This model adopts a comprehensive response decision of security fault in three principles-the maximum and minimum principle, timeliness principle, acquiescence principle, which assure optimal response countermeasure is selected for different situations. Experimental results show that the proposed model has good self-adaptation ability, timeliness and cost-sensitiveness.
NARCIS (Netherlands)
Troost, E.G.; Thorwarth, D.; Oyen, W.J.G.
2015-01-01
In many tumor types, significant effort is being put into patient-tailored adaptation of treatment to improve outcome and preferably reduce toxicity. These opportunities first arose with the introduction of modern irradiation techniques (e.g., intensity-modulated radiotherapy) combined with function
20. Adaptive Covariance Estimation with model selection
CERN Document Server
Biscay, Rolando; Loubes, Jean-Michel
2012-01-01
We provide in this paper a fully adaptive penalized procedure to select a covariance among a collection of models observing i.i.d replications of the process at fixed observation points. For this we generalize previous results of Bigot and al. and propose to use a data driven penalty to obtain an oracle inequality for the estimator. We prove that this method is an extension to the matricial regression model of the work by Baraud.
Science.gov (United States)
Matsumoto, H.; Ohnishi, T.
2. Comparative study of adaptive radiations with an example using parasitic flatworms (Platyhelminthes): Cercomeria
Energy Technology Data Exchange (ETDEWEB)
Brooks, D.R.; McLennan, D.A. (Univ. of Toronto, Ontario (Canada))
1993-11-01
3. Simulation of photosynthetically active radiation distribution in algal photobioreactors using a multidimensional spectral radiation model.
Science.gov (United States)
Kong, Bo; Vigil, R Dennis
2014-04-01
A numerical method for simulating the spectral light distribution in algal photobioreactors is developed by adapting the discrete ordinate method for solving the radiative transport equation. The technique, which was developed for two and three spatial dimensions, provides a detailed accounting for light absorption and scattering by algae in the culture medium. In particular, the optical properties of the algal cells and the radiative properties of the turbid culture medium were calculated using a method based on Mie theory and that makes use of information concerning algal pigmentation, shape, and size distribution. The model was validated using a small cylindrical bioreactor, and subsequently simulations were carried out for an annular photobioreactor configuration. It is shown that even in this relatively simple geometry, nontrivial photon flux distributions arise that cannot be predicted by one-dimensional models.
4. Handbook of anatomical models for radiation dosimetry
CERN Document Server
Eckerman, Keith F
2010-01-01
Covering the history of human model development, this title presents the major anatomical and physical models that have been developed for human body radiation protection, diagnostic imaging, and nuclear medicine therapy. It explores how these models have evolved and the role that modern technologies have played in this development.
Science.gov (United States)
Hafer, Nathaniel; Maidment, Bert W; Hatchett, Richard J
2010-12-01
The National Institute of Allergy and Infectious Diseases (NIAID) Radiation/Nuclear Medical Countermeasures Development Program has developed an integrated approach to providing the resources and expertise required for the research, discovery, and development of radiation/nuclear medical countermeasures (MCMs). These resources and services lower the opportunity costs and reduce the barriers to entry for companies interested in working in this area and accelerate translational progress by providing goal-oriented stewardship of promising projects. In many ways, the radiation countermeasures program functions as a "virtual pharmaceutical firm," coordinating the early and mid-stage development of a wide array of radiation/nuclear MCMs. This commentary describes the radiation countermeasures program and discusses a novel business model that has facilitated product development partnerships between the federal government and academic investigators and biopharmaceutical companies.
6. A general hybrid radiation transport scheme for star formation simulations on an adaptive grid
CERN Document Server
Klassen, Mikhail; Pudritz, Ralph E; Peters, Thomas; Banerjee, Robi; Buntemeyer, Lars
2014-01-01
Radiation feedback plays a crucial role in the process of star formation. In order to simulate the thermodynamic evolution of disks, filaments, and the molecular gas surrounding clusters of young stars, we require an efficient and accurate method for solving the radiation transfer problem. We describe the implementation of a hybrid radiation transport scheme in the adaptive grid-based FLASH general magnetohydrodynamics code. The hybrid scheme splits the radiative transport problem into a raytracing step and a diffusion step. The raytracer captures the first absorption event, as stars irradiate their environments, while the evolution of the diffuse component of the radiation field is handled by a flux-limited diffusion (FLD) solver. We demonstrate the accuracy of our method through a variety of benchmark tests including the irradiation of a static disk, subcritical and supercritical radiative shocks, and thermal energy equilibration. We also demonstrate the capability of our method for casting shadows and calc...
7. Adapting virtual camera behaviour through player modelling
DEFF Research Database (Denmark)
Burelli, Paolo; Yannakakis, Georgios N.
2015-01-01
Research in virtual camera control has focused primarily on finding methods to allow designers to place cameras effectively and efficiently in dynamic and unpredictable environments, and to generate complex and dynamic plans for cinematography in virtual environments. In this article, we propose...... a novel approach to virtual camera control, which builds upon camera control and player modelling to provide the user with an adaptive point-of-view. To achieve this goal, we propose a methodology to model the player’s preferences on virtual camera movements and we employ the resulting models to tailor...... the viewpoint movements to the player type and her game-play style. Ultimately, the methodology is applied to a 3D platform game and is evaluated through a controlled experiment; the results suggest that the resulting adaptive cinematographic experience is favoured by some player types and it can generate...
8. Modeling Impaired Hippocampal Neurogenesis after Radiation Exposure.
Science.gov (United States)
Cacao, Eliedonna; Cucinotta, Francis A
2016-03-01
Radiation impairment of neurogenesis in the hippocampal dentate gyrus is one of several factors associated with cognitive detriments after treatment of brain cancers in children and adults with radiation therapy. Mouse models have been used to study radiation-induced changes in neurogenesis, however the models are limited in the number of doses, dose fractions, age and time after exposure conditions that have been studied. The purpose of this study is to develop a novel predictive mathematical model of radiation-induced changes to neurogenesis using a system of nonlinear ordinary differential equations (ODEs) to represent the time, age and dose-dependent changes to several cell populations participating in neurogenesis as reported in mouse experiments exposed to low-LET radiation. We considered four compartments to model hippocampal neurogenesis and, consequently, the effects of radiation treatment in altering neurogenesis: (1) neural stem cells (NSCs), (2) neuronal progenitor cells or neuroblasts (NB), (3) immature neurons (ImN) and (4) glioblasts (GB). Because neurogenesis is decreasing with increasing mouse age, a description of the age-related dynamics of hippocampal neurogenesis is considered in the model, which is shown to be an important factor in comparisons to experimental data. A key feature of the model is the description of negative feedback regulation on early and late neuronal proliferation after radiation exposure. The model is augmented with parametric descriptions of the dose and time after irradiation dependences of activation of microglial cells and a possible shift of NSC proliferation from neurogenesis to gliogenesis reported at higher doses (∼10 Gy). Predictions for dose-fractionation regimes and for different mouse ages, and prospects for future work are then discussed.
9. Adaptive planning using megavoltage fan-beam CT for radiation therapy with testicular shielding
OpenAIRE
Yadav, Poonam; Kozak, Kevin; Tolakanahalli, Ranjini; Ramasubramanian, V.; Paliwal, Bhudatt R.; Welsh, James S.; Rong, Yi
2011-01-01
This study highlights the use of adaptive planning to accommodate testicular shielding in helical tomotherapy for malignancies of the proximal thigh. Two cases of young men with large soft tissue sarcomas of the proximal thigh are presented. After multidisciplinary evaluation, preoperative radiation therapy was recommended. Both patients were referred for sperm banking and lead shields were used to minimize testicular dose during radiation therapy. To minimize imaging artifacts, kilovoltage C...
10. Disruptive natural selection predicts divergence between the sexes during adaptive radiation.
Science.gov (United States)
De Lisle, Stephen P; Rowe, Locke
2017-05-01
11. Effects of low-dose radiation on adaptive response in colon cancer stem cells.
Science.gov (United States)
Zhao, X; Cui, J-W; Hu, J-H; Gao, S-J; Liu, X-L
2017-07-01
Biological effects of low-dose radiation (LDR) are distinguishable from those of high-dose radiation. Adaptive response is an important biological effect following low-dose radiation. Cancer stem cells (CSCs) have self-renewal and multidirectional differentiation potency which results in relapse and metastasis of cancer. In this study, we aimed to examine whether adaptive response could be induced in CSCs by LDR. Parental cells of three colon cancer cell lines (HRT18, HT29, and HCT116) and CSCs of these three cell lines were irradiated with LDR (i.e., D1) and then high-dose radiation (HDR) of X-rays (i.e., D1 + D2) or only HDR (D2 alone), followed by examination of adaptive response. Adaptive response was not observed either in the three tumor parental cells lines or in three CSCs lines following LDR, due to the lack of resistance to subsequent D2-induced cell growth inhibition. These results suggested that LDR may not induce adaptive response in colon cancer cells or colon CSCs under in vitro conditions. Our study provided experimental and clinical foundations for the application of LDR in the treatment of colon cancers.
12. Cranial shape evolution in adaptive radiations of birds: comparative morphometrics of Darwin's finches and Hawaiian honeycreepers
Science.gov (United States)
Tokita, Masayoshi; Yano, Wataru; James, Helen F.
2017-01-01
13. Dark Radiation Confronting LHC in Z' Models
CERN Document Server
Solaguren-Beascoa, A
2012-01-01
Recent cosmological data favour additional relativistic degrees of freedom beyond the three active neutrinos and photons, often referred to as "dark radiation". Extensions of the SM involving TeV-scale Z' gauge bosons generically contain superweakly interacting light right-handed neutrinos which can constitute this dark radiation. In this letter we confront the requirement on the parameters of the E6 Z' models to account for the present evidence of dark radiation with the already existing constraints from searches for new neutral gauge bosons at LHC7.
14. Adaptive evolution on a continuous lattice model
Science.gov (United States)
Claudino, Elder S.; Lyra, M. L.; Gleria, Iram; Campos, Paulo R. A.
2013-03-01
In the current work, we investigate the evolutionary dynamics of a spatially structured population model defined on a continuous lattice. In the model, individuals disperse at a constant rate v and competition is local and delimited by the competition radius R. Due to dispersal, the neighborhood size (number of individuals competing for reproduction) fluctuates over time. Here we address how these new variables affect the adaptive process. While the fixation probabilities of beneficial mutations are roughly the same as in a panmitic population for small fitness effects s, a dependence on v and R becomes more evident for large s. These quantities also strongly influence fixation times, but their dependencies on s are well approximated by s-1/2, which means that the speed of the genetic wave front is proportional to s. Most important is the observation that the model exhibits a dual behavior displaying a power-law growth for the fixation rate and speed of adaptation with the beneficial mutation rate, as observed in other spatially structured population models, while simultaneously showing a nonsaturating behavior for the speed of adaptation with the population size N, as in homogeneous populations.
15. Adaptable radiative transfer innovations for submillimetre telescopes (ARTIST). Dust polarisation module (DustPol)
Science.gov (United States)
Padovani, M.; Brinch, C.; Girart, J. M.; Jørgensen, J. K.; Frau, P.; Hennebelle, P.; Kuiper, R.; Vlemmings, W. H. T.; Bertoldi, F.; Hogerheijde, M.; Juhasz, A.; Schaaf, R.
2012-07-01
We present a new publicly available tool (DustPol) aimed to model the polarised thermal dust emission. The module DustPol, which is publicly available, is part of the ARTIST (Adaptable Radiative Transfer Innovations for Submillimetre Telescopes) package, which also offers tools for modelling the polarisation of line emission together with a model library and a Python-based user interface. DustPol can easily manage analytical as well as pre-gridded models to generate synthetic maps of the Stokes I, Q, and U parameters. These maps are stored in FITS format which is straightforwardly read by the data reduction software used, e.g., by the Atacama Large Millimeter Array (ALMA). This turns DustPol into a powerful engine for the prediction of the expected polarisation features of a source observed with ALMA or the Planck satellite as well as for the interpretation of existing submillimetre observations obtained with other telescopes. DustPol allows the parameterisation of the maximum degree of polarisation and we find that, in a prestellar core, if there is depolarisation, this effect should happen at densities of 106 cm-3 or larger. We compare a model generated by DustPol with the observational polarisation data of the low-mass Class 0 object NGC 1333 IRAS 4A, finding that the total and the polarised emission are consistent.
16. Replanning Criteria and Timing Definition for Parotid Protection-Based Adaptive Radiation Therapy in Nasopharyngeal Carcinoma
Directory of Open Access Journals (Sweden)
Wei-Rong Yao
2015-01-01
Full Text Available The goal of this study was to evaluate real-time volumetric and dosimetric changes of the parotid gland so as to determine replanning criteria and timing for parotid protection-based adaptive radiation therapy in nasopharyngeal carcinoma. Fifty NPC patients were treated with helical tomotherapy; volumetric and dosimetric (Dmean, V1, and D50 changes of the parotid gland at the 1st, 6th, 11th, 16th, 21st, 26th, 31st, and 33rd fractions were evaluated. The clinical parameters affecting these changes were studied by analyses of variance methods for repeated measures. Factors influencing the actual parotid dose were analyzed by a multivariate logistic regression model. The cut-off values predicting parotid overdose were developed from receiver operating characteristic curves and judged by combining them with a diagnostic test consistency check. The median absolute value and percentage of parotid volume reduction were 19.51 cm3 and 35%, respectively. The interweekly parotid volume varied significantly (p<0.05. The parotid Dmean, V1, and D50 increased by 22.13%, 39.42%, and 48.45%, respectively. The actual parotid dose increased by an average of 11.38% at the end of radiation therapy. Initial parotid volume, initial parotid Dmean, and weight loss rate are valuable indicators for parotid protection-based replanning.
17. Enemy at the gates: Rapid defensive trait diversification in an adaptive radiation of lizards.
Science.gov (United States)
Broeckhoven, Chris; Diedericks, Genevieve; Hui, Cang; Makhubo, Buyisile G; Mouton, P le Fras N
2016-11-01
Adaptive radiation (AR), the product of rapid diversification of an ancestral species into novel adaptive zones, has become pivotal in our understanding of biodiversity. Although it has widely been accepted that predators may drive the process of AR by creating ecological opportunity (e.g., enemy-free space), the role of predators as selective agents in defensive trait diversification remains controversial. Using phylogenetic comparative methods, we provide evidence for an "early burst" in the diversification of antipredator phenotypes in Cordylinae, a relatively small AR of morphologically diverse southern African lizards. The evolution of body armor appears to have been initially rapid, but slowed down over time, consistent with the ecological niche-filling model. We suggest that the observed "early burst" pattern could be attributed to shifts in vulnerability to different types of predators (i.e., aerial versus terrestrial) associated with thermal habitat partitioning. These results provide empirical evidence supporting the hypothesis that predators or the interaction therewith might be key components of ecological opportunity, although the way in which predators influence morphological diversification requires further study. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.
18. Model-Free Adaptive Heating Process Control
OpenAIRE
Ivana LUKÁČOVÁ; Piteľ, Ján
2009-01-01
The aim of this paper is to analyze the dynamic behaviour of a Model-Free Adaptive (MFA) heating process control. The MFA controller is designed as three layer neural network with proportional element. The method of backward propagation of errors was used for neural network training. Visualization and training of the artificial neural network was executed by Netlab in Matlab environment. Simulation of the MFA heating process control with outdoor temperature compensation has proved better resu...
Science.gov (United States)
2017-04-01
Organization (NATO) Sensors Electronics Technology (SET)-227 Panel on Cognitive Radar. The FAR M&S architecture developed in Phase I allows for...Air Force’s previously developed radar M&S tools. This report is organized as follows. In Chapter 3, we provide an overview of the FAR framework...AFRL-RY-WP-TR-2017-0074 FULLY ADAPTIVE RADAR MODELING AND SIMULATION DEVELOPMENT Kristine L. Bell and Anthony Kellems Metron, Inc
Science.gov (United States)
Gonsalves, Paul G.; Dougherty, Edward T.
2006-05-01
The pervasiveness of software and networked information systems is evident across a broad spectrum of business and government sectors. Such reliance provides an ample opportunity not only for the nefarious exploits of lone wolf computer hackers, but for more systematic software attacks from organized entities. Much effort and focus has been placed on preventing and ameliorating network and OS attacks, a concomitant emphasis is required to address protection of mission critical software. Typical software protection technique and methodology evaluation and verification and validation (V&V) involves the use of a team of subject matter experts (SMEs) to mimic potential attackers or hackers. This manpower intensive, time-consuming, and potentially cost-prohibitive approach is not amenable to performing the necessary multiple non-subjective analyses required to support quantifying software protection levels. To facilitate the evaluation and V&V of software protection solutions, we have designed and developed a prototype adaptive cyber attack modeling system. Our approach integrates an off-line mechanism for rapid construction of Bayesian belief network (BN) attack models with an on-line model instantiation, adaptation and knowledge acquisition scheme. Off-line model construction is supported via a knowledge elicitation approach for identifying key domain requirements and a process for translating these requirements into a library of BN-based cyber-attack models. On-line attack modeling and knowledge acquisition is supported via BN evidence propagation and model parameter learning.
1. RRTM: A rapid radiative transfer model
Energy Technology Data Exchange (ETDEWEB)
Mlawer, E.J.; Taubman, S.J.; Clough, S.A. [Atmospheric and Environmental Research, Inc., Cambridge, MA (United States)
1996-04-01
A rapid radiative transfer model (RRTM) for the calculation of longwave clear-sky fluxes and cooling rates has been developed. The model, which uses the correlated-k method, is both accurate and computationally fast. The foundation for RRTM is the line-by-line radiative transfer model (LBLRTM) from which the relevant k-distributions are obtained. LBLRTM, which has been extensively validated against spectral observations e.g., the high-resolution sounder and the Atmospheric Emitted Radiance Interferometer, is used to validate the flux and cooling rate results from RRTM. Validations of RRTMs results have been performed for the tropical, midlatitude summer, and midlatitude winter atmospheres, as well as for the four Intercomparison of Radiation Codes in Climate Models (ICRCCM) cases from the Spectral Radiance Experiment (SPECTRE). Details of some of these validations are presented below. RRTM has the identical atmospheric input module as LBLRTM, facilitating intercomparisons with LBLRTM and application of the model at the Atmospheric Radiation Measurement Cloud and Radiation Testbed sites.
2. Canonical Ensemble Model for Black Hole Radiation
Jingyi Zhang
2014-09-01
In this paper, a canonical ensemble model for the black hole quantum tunnelling radiation is introduced. In this model the probability distribution function corresponding to the emission shell is calculated to second order. The formula of pressure and internal energy of the thermal system is modified, and the fundamental equation of thermodynamics is also discussed.
3. Adaptive Control and Synchronization of the Shallow Water Model
Directory of Open Access Journals (Sweden)
P. Sangapate
2012-01-01
Full Text Available The shallow water model is one of the important models in dynamical systems. This paper investigates the adaptive chaos control and synchronization of the shallow water model. First, adaptive control laws are designed to stabilize the shallow water model. Then adaptive control laws are derived to chaos synchronization of the shallow water model. The sufficient conditions for the adaptive control and synchronization have been analyzed theoretically, and the results are proved using a Barbalat's Lemma.
4. Ionizing radiation-induced adaptive response in fibroblasts under both monolayer and 3-dimensional conditions.
Science.gov (United States)
Zhao, Yinlong; Zhong, Rui; Sun, Liguang; Jia, Jie; Ma, Shumei; Liu, Xiaodong
2015-01-01
5. A Model for Climate Change Adaptation
Science.gov (United States)
Pasqualini, D.; Keating, G. N.
2009-12-01
Climate models predict serious impacts on the western U.S. in the next few decades, including increased temperatures and reduced precipitation. In combination, these changes are linked to profound impacts on fundamental systems, such as water and energy supplies, agriculture, population stability, and the economy. Global and national imperatives for climate change mitigation and adaptation are made actionable at the state level, for instance through greenhouse gas (GHG) emission regulations and incentives for renewable energy sources. However, adaptation occurs at the local level, where energy and water usage can be understood relative to local patterns of agriculture, industry, and culture. In response to the greenhouse gas emission reductions required by California’s Assembly Bill 32 (2006), Sonoma County has committed to sharp emissions reductions across several sectors, including water, energy, and transportation. To assist Sonoma County develop a renewable energy (RE) portfolio to achieve this goal we have developed an integrated assessment model, CLEAR (CLimate-Energy Assessment for Resiliency) model. Building on Sonoma County’s existing baseline studies of energy use, carbon emissions and potential RE sources, the CLEAR model simulates the complex interactions among technology deployment, economics and social behavior. This model enables assessment of these and other components with specific analysis of their coupling and feedbacks because, due to the complex nature of the problem, the interrelated sectors cannot be studied independently. The goal is an approach to climate change mitigation and adaptation that is replicable for use by other interested communities. The model user interfaces helps stakeholders and policymakers understand options for technology implementation.
6. nIFTy galaxy cluster simulations - II. Radiative models
Science.gov (United States)
Sembolini, Federico; Elahi, Pascal Jahan; Pearce, Frazer R.; Power, Chris; Knebe, Alexander; Kay, Scott T.; Cui, Weiguang; Yepes, Gustavo; Beck, Alexander M.; Borgani, Stefano; Cunnama, Daniel; Davé, Romeel; February, Sean; Huang, Shuiyao; Katz, Neal; McCarthy, Ian G.; Murante, Giuseppe; Newton, Richard D. A.; Perret, Valentin; Puchwein, Ewald; Saro, Alexandro; Schaye, Joop; Teyssier, Romain
2016-07-01
7. Infrared radiation models for atmospheric ozone
Science.gov (United States)
Kratz, David P.; Ces, Robert D.
1988-01-01
A hierarchy of line-by-line, narrow-band, and broadband infrared radiation models are discussed for ozone, a radiatively important atmospheric trace gas. It is shown that the narrow-band (Malkmus) model is in near-precise agreement with the line-by-line model, thus providing a means of testing narrow-band Curtis-Godson scaling, and it is found that this scaling procedure leads to errors in atmospheric fluxes of up to 10 percent. Moreover, this is a direct consequence of the altitude dependence of the ozone mixing ratio. Somewhat greater flux errors arise with use of the broadband model, due to both a lesser accuracy of the broadband scaling procedure and to inherent errors within the broadband model, despite the fact that this model has been tuned to the line-by-line model.
8. Non-LTE modeling of radiatively driven dense plasmas
Science.gov (United States)
Scott, H. A.
2017-03-01
There are now several experimental facilities that use strong X-ray fields to produce plasmas with densities ranging from ˜1 to ˜103 g/cm3. Large laser facilities, such as the National Ignition Facility (NIF) and the Omega laser reach high densities with radiatively driven compression, short-pulse lasers such as XFELs produce solid density plasmas on very short timescales, and the Orion laser facility combines these methods. Despite the high densities, these plasmas can be very far from LTE, due to large radiation fields and/or short timescales, and simulations mostly use collisional-radiative (CR) modeling which has been adapted to handle these conditions. These dense plasmas present challenges to CR modeling. Ionization potential depression (IPD) has received much attention recently as researchers work to understand experimental results from LCLS and Orion [1,2]. However, incorporating IPD into a CR model is only one challenge presented by these conditions. Electron degeneracy and the extent of the state space can also play important roles in the plasma energetics and radiative properties, with effects evident in recent observations [3,4]. We discuss the computational issues associated with these phenomena and methods for handling them.
Energy Technology Data Exchange (ETDEWEB)
Tuomikoski, Laura; Collan, Juhani; Keyrilaeinen, Jani; Saarilahti, Kauko; Tenhunen, Mikko [Dept. of Oncology, Helsinki Univ. Central Hospital, Helsinki (Finland)], e-mail: [email protected]; Korhonen, Juha [Dept. of Oncology, Helsinki Univ. Central Hospital, Helsinki (Finland); Clinical Research Inst. Helsinki Univ. Central Hospital Ltd, Helsinki (Finland); Visapaeae, Harri [Dept. of Oncology, Helsinki Univ. Central Hospital, Helsinki (Finland); Dept. of Urology, Helsinki Univ. Central Hospital, Helsinki (Finland); Sairanen, Jukka [Dept. of Urology, Helsinki Univ. Central Hospital, Helsinki (Finland)
2013-10-15
10. Disentangling adaptive evolutionary radiations and the role of diet in promoting diversification on islands
Science.gov (United States)
Demiguel, Daniel
2016-07-01
Although the initial formulation of modern concepts of adaptive radiation arose from consideration of the fossil data, rigorous attempts to identify this phenomenon in the fossil record are largely uncommon. Here I focus on direct evidence of the diet (through tooth-wear patterns) and ecologically-relevant traits of one of the most renowned fossil vertebrates-the Miocene ruminant Hoplitomeryx from the island of Gargano-to deepen our understanding of the most likely causal forces under which adaptive radiations emerge on islands. Results show how accelerated accumulation of species and early-bursts of ecological diversification occur after invading an island, and provide insights on the interplay between diet and demographic (population-density), ecological (competition/food requirements) and abiotic (climate-instability) factors, identified as drivers of adaptive diversification. A pronounced event of overpopulation and a phase of aridity determined most of the rate and magnitude of radiation, and pushed species to expand diets from soft-leafy foods to tougher-harder items. Unexpectedly, results show that herbivorous mammals are restricted to browsing habits on small-islands, even if bursts of ecological diversification and dietary divergence occur. This study deepens our understanding of the mechanisms promoting adaptive radiations, and forces us to reevaluate the role of diet in the origins and evolution of islands mammals.
11. Income distribution: An adaptive heterogeneous model
Science.gov (United States)
da Silva, L. C.; de Figueirêdo, P. H.
2014-02-01
In this communication an adaptive process is introduced into a many-agent model for closed economic system in order to establish general features of income distribution. In this new version agents are able to modify their exchange parameter ωi of resources through an adaptive process. The conclusions indicate that assuming an instantaneous learning behavior of all agents a Γ-distribution for income is reproduced while a frozen behavior establishes a Pareto’s distribution for income with an exponent ν=0.94±0.02. A third case occurs when a heterogeneous “inertia” behavior is introduced leading us to a Γ-distribution at the low income regime and a power-law decay for the large income values with an exponent ν=2.05±0.05. This method enables investigation of the resources flux in the economic environment and produces also bounding values for the Gini index comparable with data evidences.
12. Genomic variation at the tips of the adaptive radiation of Darwin's finches.
Science.gov (United States)
Chaves, Jaime A; Cooper, Elizabeth A; Hendry, Andrew P; Podos, Jeffrey; De León, Luis F; Raeymaekers, Joost A M; MacMillan, W Owen; Uy, J Albert C
2016-11-01
13. Simulations of recoiling black holes: adaptive mesh refinement and radiative transfer
Science.gov (United States)
Meliani, Zakaria; Mizuno, Yosuke; Olivares, Hector; Porth, Oliver; Rezzolla, Luciano; Younsi, Ziri
2017-02-01
Context. In many astrophysical phenomena, and especially in those that involve the high-energy regimes that always accompany the astronomical phenomenology of black holes and neutron stars, physical conditions that are achieved are extreme in terms of speeds, temperatures, and gravitational fields. In such relativistic regimes, numerical calculations are the only tool to accurately model the dynamics of the flows and the transport of radiation in the accreting matter. Aims: We here continue our effort of modelling the behaviour of matter when it orbits or is accreted onto a generic black hole by developing a new numerical code that employs advanced techniques geared towards solving the equations of general-relativistic hydrodynamics. Methods: More specifically, the new code employs a number of high-resolution shock-capturing Riemann solvers and reconstruction algorithms, exploiting the enhanced accuracy and the reduced computational cost of adaptive mesh-refinement (AMR) techniques. In addition, the code makes use of sophisticated ray-tracing libraries that, coupled with general-relativistic radiation-transfer calculations, allow us to accurately compute the electromagnetic emissions from such accretion flows. Results: We validate the new code by presenting an extensive series of stationary accretion flows either in spherical or axial symmetry that are performed either in two or three spatial dimensions. In addition, we consider the highly nonlinear scenario of a recoiling black hole produced in the merger of a supermassive black-hole binary interacting with the surrounding circumbinary disc. In this way, we can present for the first time ray-traced images of the shocked fluid and the light curve resulting from consistent general-relativistic radiation-transport calculations from this process. Conclusions: The work presented here lays the ground for the development of a generic computational infrastructure employing AMR techniques to accurately and self
14. An adaptive contextual quantum language model
Science.gov (United States)
Li, Jingfei; Zhang, Peng; Song, Dawei; Hou, Yuexian
2016-08-01
User interactions in search system represent a rich source of implicit knowledge about the user's cognitive state and information need that continuously evolves over time. Despite massive efforts that have been made to exploiting and incorporating this implicit knowledge in information retrieval, it is still a challenge to effectively capture the term dependencies and the user's dynamic information need (reflected by query modifications) in the context of user interaction. To tackle these issues, motivated by the recent Quantum Language Model (QLM), we develop a QLM based retrieval model for session search, which naturally incorporates the complex term dependencies occurring in user's historical queries and clicked documents with density matrices. In order to capture the dynamic information within users' search session, we propose a density matrix transformation framework and further develop an adaptive QLM ranking model. Extensive comparative experiments show the effectiveness of our session quantum language models.
15. Adaptive Lattice Boltzmann Model for Compressible Flows
Institute of Scientific and Technical Information of China (English)
2000-01-01
A new lattice Boltzmann model for compressible flows is presented. The main difference from the standard lattice Boltzmann model is that the particle velocities are no longer constant, but vary with the mean velocity and internal energy. The adaptive nature of the particle velocities permits the mean flow to have a high Mach number. The introduction of a particle potential energy makes the model suitable for a perfect gas with arbitrary specific heat ratio. The Navier-Stokes (N-S) equations are derived by the Chapman-Enskog method from the BGK Boltzmann equation. Two kinds of simulations have been carried out on the hexagonal lattice to test the proposed model. One is the Sod shock-tube simulation. The other is a strong shock of Mach number 5.09 diffracting around a corner.
16. Adaptive response in frogs chronically exposed to low doses of ionizing radiation in the environment
Energy Technology Data Exchange (ETDEWEB)
Audette-Stuart, M., E-mail: [email protected] [Environmental Technologies Branch, Atomic Energy of Canada Limited, Chalk River Laboratories, Chalk River, Ontario, K0J 1P0 (Canada); Kim, S.B.; McMullin, D.; Festarini, A.; Yankovich, T.L.; Carr, J.; Mulpuru, S. [Environmental Technologies Branch, Atomic Energy of Canada Limited, Chalk River Laboratories, Chalk River, Ontario, K0J 1P0 (Canada)
2011-06-15
Using the micronucleus assay, decreased levels of DNA damage were found after high dose ionizing radiation exposure of liver cells taken from frogs inhabiting a natural environment with above-background levels of ionizing radiation, compared to cells taken from frogs inhabiting background areas. The data obtained from a small number of animals suggest that stress present in the above-background environment could induce an adaptive response to ionizing radiation. This study did not reveal harmful effects of exposure to low levels of radioactivity. On the contrary, stress present in the above-background area may serve to enhance cellular defense mechanisms. - Highlights: > Frogs were collected from background and higher tritium level habitats. > The micronucleus assay was conducted on liver cells obtained from the frogs. > No detrimental effects were noted in frogs exposed to elevated tritium. > Adaptive responses were observed in frogs exposed to elevated tritium.
17. Regulation Of Nf=kb And Mnsod In Low Dose Radiation Induced Adaptive Protection Of Mouse And Human Skin Cells
Energy Technology Data Exchange (ETDEWEB)
Jian Li
2012-11-07
A sampling of publications resulting from this grant is provided. One is on the subject of NF-κB-Mediated HER2 Overexpression in Radiation-Adaptive Resistance. Another is on NF-κB-mediated adaptive resistance to ionizing radiation.
18. On adaptive refinements in discrete probabilistic fracture models
Directory of Open Access Journals (Sweden)
J. Eliáš
2017-01-01
Full Text Available The possibility to adaptively change discretization density is a well acknowledged and used feature of many continuum models. It is employed to save computational time and increase solution accuracy. Recently, adaptivity has been introduced also for discrete particle models. This contribution applies adaptive technique in probabilistic discrete modelling where material properties are varying in space according to a random field. The random field discretization is adaptively refined hand in hand with the model geometry.
19. Synaptic dynamics: linear model and adaptation algorithm.
Science.gov (United States)
Yousefi, Ali; Dibazar, Alireza A; Berger, Theodore W
2014-08-01
In this research, temporal processing in brain neural circuitries is addressed by a dynamic model of synaptic connections in which the synapse model accounts for both pre- and post-synaptic processes determining its temporal dynamics and strength. Neurons, which are excited by the post-synaptic potentials of hundred of the synapses, build the computational engine capable of processing dynamic neural stimuli. Temporal dynamics in neural models with dynamic synapses will be analyzed, and learning algorithms for synaptic adaptation of neural networks with hundreds of synaptic connections are proposed. The paper starts by introducing a linear approximate model for the temporal dynamics of synaptic transmission. The proposed linear model substantially simplifies the analysis and training of spiking neural networks. Furthermore, it is capable of replicating the synaptic response of the non-linear facilitation-depression model with an accuracy better than 92.5%. In the second part of the paper, a supervised spike-in-spike-out learning rule for synaptic adaptation in dynamic synapse neural networks (DSNN) is proposed. The proposed learning rule is a biologically plausible process, and it is capable of simultaneously adjusting both pre- and post-synaptic components of individual synapses. The last section of the paper starts with presenting the rigorous analysis of the learning algorithm in a system identification task with hundreds of synaptic connections which confirms the learning algorithm's accuracy, repeatability and scalability. The DSNN is utilized to predict the spiking activity of cortical neurons and pattern recognition tasks. The DSNN model is demonstrated to be a generative model capable of producing different cortical neuron spiking patterns and CA1 Pyramidal neurons recordings. A single-layer DSNN classifier on a benchmark pattern recognition task outperforms a 2-Layer Neural Network and GMM classifiers while having fewer numbers of free parameters and
20. Model Driven Mutation Applied to Adaptative Systems Testing
CERN Document Server
Bartel, Alexandre; Munoz, Freddy; Klein, Jacques; Mouelhi, Tejeddine; Traon, Yves Le
2012-01-01
Dynamically Adaptive Systems modify their behav- ior and structure in response to changes in their surrounding environment and according to an adaptation logic. Critical sys- tems increasingly incorporate dynamic adaptation capabilities; examples include disaster relief and space exploration systems. In this paper, we focus on mutation testing of the adaptation logic. We propose a fault model for adaptation logics that classifies faults into environmental completeness and adaptation correct- ness. Since there are several adaptation logic languages relying on the same underlying concepts, the fault model is expressed independently from specific adaptation languages. Taking benefit from model-driven engineering technology, we express these common concepts in a metamodel and define the operational semantics of mutation operators at this level. Mutation is applied on model elements and model transformations are used to propagate these changes to a given adaptation policy in the chosen formalism. Preliminary resul...
1. Modeling the radiation pattern of LEDs.
Science.gov (United States)
Moreno, Ivan; Sun, Ching-Cherng
2008-02-01
Light-emitting diodes (LEDs) come in many varieties and with a wide range of radiation patterns. We propose a general, simple but accurate analytic representation for the radiation pattern of the light emitted from an LED. To accurately render both the angular intensity distribution and the irradiance spatial pattern, a simple phenomenological model takes into account the emitting surfaces (chip, chip array, or phosphor surface), and the light redirected by both the reflecting cup and the encapsulating lens. Mathematically, the pattern is described as the sum of a maximum of two or three Gaussian or cosine-power functions. The resulting equation is widely applicable for any kind of LED of practical interest. We accurately model a wide variety of radiation patterns from several world-class manufacturers.
2. The Dynamics of Incomplete Lineage Sorting across the Ancient Adaptive Radiation of Neoavian Birds.
Directory of Open Access Journals (Sweden)
Alexander Suh
2015-08-01
Full Text Available The diversification of neoavian birds is one of the most rapid adaptive radiations of extant organisms. Recent whole-genome sequence analyses have much improved the resolution of the neoavian radiation and suggest concurrence with the Cretaceous-Paleogene (K-Pg boundary, yet the causes of the remaining genome-level irresolvabilities appear unclear. Here we show that genome-level analyses of 2,118 retrotransposon presence/absence markers converge at a largely consistent Neoaves phylogeny and detect a highly differential temporal prevalence of incomplete lineage sorting (ILS, i.e., the persistence of ancestral genetic variation as polymorphisms during speciation events. We found that ILS-derived incongruences are spread over the genome and involve 35% and 34% of the analyzed loci on the autosomes and the Z chromosome, respectively. Surprisingly, Neoaves diversification comprises three adaptive radiations, an initial near-K-Pg super-radiation with highly discordant phylogenetic signals from near-simultaneous speciation events, followed by two post-K-Pg radiations of core landbirds and core waterbirds with much less pronounced ILS. We provide evidence that, given the extreme level of up to 100% ILS per branch in super-radiations, particularly rapid speciation events may neither resemble a fully bifurcating tree nor are they resolvable as such. As a consequence, their complex demographic history is more accurately represented as local networks within a species tree.
3. Radiation hydrodynamics using characteristics on adaptive decomposed domains for massively parallel star formation simulations
Science.gov (United States)
Buntemeyer, Lars; Banerjee, Robi; Peters, Thomas; Klassen, Mikhail; Pudritz, Ralph E.
2016-02-01
We present an algorithm for solving the radiative transfer problem on massively parallel computers using adaptive mesh refinement and domain decomposition. The solver is based on the method of characteristics which requires an adaptive raytracer that integrates the equation of radiative transfer. The radiation field is split into local and global components which are handled separately to overcome the non-locality problem. The solver is implemented in the framework of the magneto-hydrodynamics code FLASH and is coupled by an operator splitting step. The goal is the study of radiation in the context of star formation simulations with a focus on early disc formation and evolution. This requires a proper treatment of radiation physics that covers both the optically thin as well as the optically thick regimes and the transition region in particular. We successfully show the accuracy and feasibility of our method in a series of standard radiative transfer problems and two 3D collapse simulations resembling the early stages of protostar and disc formation.
4. nIFTy galaxy cluster simulations II: radiative models
CERN Document Server
Sembolini, Federico; Pearce, Frazer R; Power, Chris; Knebe, Alexander; Kay, Scott T; Cui, Weiguang; Yepes, Gustavo; Beck, Alexander M; Borgani, Stefano; Cunnama, Daniel; Davé, Romeel; February, Sean; Huang, Shuiyao; Katz, Neal; McCarthy, Ian G; Murante, Giuseppe; Newton, Richard D A; Perret, Valentin; Saro, Alexandro; Schaye, Joop; Teyssier, Romain
2015-01-01
We have simulated the formation of a massive galaxy cluster (M$_{200}^{\\rm crit}$ = 1.1$\\times$10$^{15}h^{-1}M_{\\odot}$) in a $\\Lambda$CDM universe using 10 different codes (RAMSES, 2 incarnations of AREPO and 7 of GADGET), modeling hydrodynamics with full radiative subgrid physics. These codes include Smoothed-Particle Hydrodynamics (SPH), spanning traditional and advanced SPH schemes, adaptive mesh and moving mesh codes. Our goal is to study the consistency between simulated clusters modeled with different radiative physical implementations - such as cooling, star formation and AGN feedback. We compare images of the cluster at $z=0$, global properties such as mass, and radial profiles of various dynamical and thermodynamical quantities. We find that, with respect to non-radiative simulations, dark matter is more centrally concentrated, the extent not simply depending on the presence/absence of AGN feedback. The scatter in global quantities is substantially higher than for non-radiative runs. Intriguingly, a...
5. Fast and robust online adaptive planning in stereotactic MR-guided adaptive radiation therapy (SMART) for pancreatic cancer.
Science.gov (United States)
Bohoudi, O; Bruynzeel, A M E; Senan, S; Cuijpers, J P; Slotman, B J; Lagerwaard, F J; Palacios, M A
2017-08-12
Science.gov (United States)
Givnish, Thomas J; Montgomery, Rebecca A
2014-03-22
Species in an adaptive radiation often occupy different habitats so that individuals of each species develop under different conditions. Showing that a radiation is adaptive thus requires evidence that taxa have diverged genetically and that each has an ecological advantage in using particular habitats or resources, taking into account both phenotypic plasticity and phylogenetic relationships among species. Here, we use a common-garden experiment to show that representative species of Hawaiian lobeliads have diverged adaptively in their leaf-level photosynthetic light responses. Across species, plants genetically shifted their photosynthetic physiology with native light regime in accord with theoretical predictions and exhibited adaptive crossover in net carbon gain-that is, species native to a given light regime outperformed others only under conditions similar to those they occupy in the field, with the rank order of species based on photosynthesis per unit leaf mass changing with light level. These findings make a powerful case for adaptation of photosynthetic light responses to native light regimes and, combined with our earlier field studies, provide the strongest demonstration to date for the evolution of divergent adaptations for energy capture in any group of closely related plants.
7. Fracture model of radiation blistering
Energy Technology Data Exchange (ETDEWEB)
1979-06-01
The formation process of blisters is interpreted by a fracture model on the basis of the stress fields around a lenticular bubble calculated in a previous paper. This model implicitly presumes a microcrack nucleated at a depth near the projected range of the ions. Two factors are separated theoretically to explain the blister formation: One is a geometrical factor which depends only on the ratio of size to depth, from a free surface, and the other factor is proportional to the square of the ratio between the internal gas pressure of the bubble to plastic yield stress of the target materials, depending entirely on the physical and chemical properties of the materials and gas atoms. The relation between the blister diameter and the cover thickness must be basically linear as expected from the first factor, but is modulated by the second factor, giving a slight departure from linearity as observed by experiment. The ratio of the gas pressure to the yield stress must be 0.02--0.2 in magnitude and depends on the ion energy and the target materials. This value leads to an estimation that the amount of gas atoms contained in the blister is about 10% of the injected ions. Griffith's criterion for the crack propagation in the subsurface layer with taking into account of ductility of the materials near the crack tip was derived, and showed that the estimated internal pressure of the blister is far smaller than the necessary pressure to satisfy the criterion. The objections against the gas-pressure model were criticized on the basis of the present model.
8. Adaptive Genetic Algorithm Model for Intrusion Detection
Directory of Open Access Journals (Sweden)
K. S. Anil Kumar
2012-09-01
Full Text Available Intrusion detection systems are intelligent systems designed to identify and prevent the misuse of computer networks and systems. Various approaches to Intrusion Detection are currently being used, but they are relatively ineffective. Thus the emerging network security systems need be part of the life system and this ispossible only by embedding knowledge into the network. The Adaptive Genetic Algorithm Model - IDS comprising of K-Means clustering Algorithm, Genetic Algorithm and Neural Network techniques. Thetechnique is tested using multitude of background knowledge sets in DARPA network traffic datasets.
9. A Model for Dynamic Adaptive Coscheduling
Institute of Scientific and Technical Information of China (English)
LU Sanglu; ZHOU Xiaobo; XIE Li
1999-01-01
This paper proposes a dynamic adaptive coscheduling modelDASIC to take advantage of excess available resources in anetwork of workstations (NOW). Besides coscheduling related subtasksdynamically, DASIC can scale up or down the process space dependingupon the number of available processors on an NOW. Based on thedynamic idle processor group (IPG), DASIC employs three modules: thecoscheduling module, the scalable scheduling module and the loadbalancing module, and uses six algorithms to achieve scalability. Asimplified DASIC was also implemented, and experimental results arepresented in this paper, which show that it can maximize systemutilization, and achieve task parallelism as much as possible.
10. Status of Galileo interim radiation electron model
Science.gov (United States)
Garrett, H. B.; Jun, I.; Ratliff, J. M.; Evans, R. W.; Clough, G. A.; McEntire, R. W.
2003-01-01
Measurements of the high energy, omni-directional electron environment by the Galileo spacecraft Energetic Particle Detector (EDP) were used to develop a new model of Jupiter's trapped electron radiation in the jovian equatorial plane for the range 8 to 16 Jupiter radii.
11. The JPL Neptune Radiation Model (NMOD)
Science.gov (United States)
Garrett, Henry; Evans, Robin
2017-01-01
The objective of this study is the development of a comprehensive radiation model of the Neptunian environment for JPL mission planning. The ultimate goal is to provide a description of the high-energy electron and proton environments and the magnetic field at Neptune that can be used for engineering design. The JPL Neptune Radiation Model (NMOD) models the high-energy electrons and protons between 0.025 MeV and 5 MeV based on the California Institute of Technology's Cosmic Ray Subsystem and the Applied Physics Laboratory's Low Energy Charged Particle Detector on Voyager 2. As in previous JPL radiation models, the form of the Neptunian model is based on magnetic field coordinates and requires a conversion from spacecraft coordinates to Neptunian-centered magnetic "B-L" coordinates. Two types of magnetic field models have been developed for Neptune: 1) simple "offset, tilted dipoles" (OTD), and 2) a complex, multi-pole expansion model ("O8"). A review of the existing data on Neptune and a search of the NASA Planetary Data System (PDS) were completed to obtain the most current descriptions of the Neptunian high-energy particle environment. These data were fit in terms of the O8 B-L coordinates to develop the electron and proton flux models. The flux predictions of the new model were used to estimate the total ionizing dose (TID) rate along the Neptunian equator, meridional flux contours for the electrons and protons, and for flux and dose comparisons with the other radiation belts in the Solar System.
12. Molecular mechanisms involved in adaptive responses to radiation, UV light, and heat.
Science.gov (United States)
Takahashi, Akihisa; Ohnishi, Takeo
2009-09-01
Viable organisms recognize and respond to environmental changes or stresses. When these environmental changes and their responses by organisms are extreme, they can limit viability. However, organisms can adapt to these different stresses by utilizing different possible responses via signal transduction pathways when the stress is not lethal. In particular, prior mild stresses can provide some aid to prepare organisms for subsequent more severe stresses. These adjustments or adaptations for future stresses have been called adaptive responses. These responses are present in bacteria, plants and animals. The following review covers recent research which can help describe or postulate possible mechanisms which may be active in producing adaptive responses to radiation, ultraviolet light, and heat.
13. Radiatively induced quark and lepton mass model
Science.gov (United States)
2016-10-01
We propose a radiatively induced quark and lepton mass model in the first and second generation with extra U (1) gauge symmetry and vector-like fermions. Then we analyze the allowed regions which simultaneously satisfy the FCNCs for the quark sector, LFVs including μ- e conversion, the quark mass and mixing, and the lepton mass and mixing. Also we estimate the typical value for the (g - 2) μ in our model.
14. Radiative transfer model for Solar System ices
Science.gov (United States)
Andrieu, F.; Schmidt, F.; Douté, S.; Schmitt, B.; Brissaud, O.
2015-10-01
We developed a radiative transfer model [1] that simulates the bidirectional reflectance of a contaminated slab layer of ice overlaying a granular medium, under geometrical optics conditions. Designed for planetary studies, this model has a fast computer implementation and thus is suitable for planetary high spatial/spectral resolution hyperspectral data analysis. We will present here its principles, its numerical and experimental validations and its possible applications.
15. Context dependence in complex adaptive landscapes: frequency and trait-dependent selection surfaces within an adaptive radiation of Caribbean pupfishes.
Science.gov (United States)
Martin, Christopher H
2016-06-01
The adaptive landscape provides the foundational bridge between micro- and macroevolution. One well-known caveat to this perspective is that fitness surfaces depend on ecological context, including competitor frequency, traits measured, and resource abundance. However, this view is based largely on intraspecific studies. It is still unknown how context-dependence affects the larger features of peaks and valleys on the landscape which ultimately drive speciation and adaptive radiation. Here, I explore this question using one of the most complex fitness landscapes measured in the wild in a sympatric pupfish radiation endemic to San Salvador Island, Bahamas by tracking survival and growth of laboratory-reared F2 hybrids. I present new analyses of the effects of competitor frequency, dietary isotopes, and trait subsets on this fitness landscape. Contrary to expectations, decreasing competitor frequency increased survival only among very common phenotypes, whereas less common phenotypes rarely survived despite few competitors, suggesting that performance, not competitor frequency, shapes large-scale features of the fitness landscape. Dietary isotopes were weakly correlated with phenotype and growth, but did not explain additional survival variation. Nonlinear fitness surfaces varied substantially among trait subsets, revealing one-, two-, and three-peak landscapes, demonstrating the complexity of selection in the wild, even among similar functional traits. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.
16. Adaptation dynamics of the quasispecies model
Kavita Jain
2008-08-01
We study the adaptation dynamics of an initially maladapted population evolving via the elementary processes of mutation and selection. The evolution occurs on rugged fitness landscapes which are defined on the multi-dimensional genotypic space and have many local peaks separated by low fitness valleys. We mainly focus on the Eigen’s model that describes the deterministic dynamics of an infinite number of self-replicating molecules. In the stationary state, for small mutation rates such a population forms a quasispecies which consists of the fittest genotype and its closely related mutants. The quasispecies dynamics on rugged fitness landscape follow a punctuated (or step-like) pattern in which a population jumps from a low fitness peak to a higher one, stays there for a considerable time before shifting the peak again and eventually reaches the global maximum of the fitness landscape. We calculate exactly several properties of this dynamical process within a simplified version of the quasispecies model.
17. Adaptation dynamics of the quasispecies model
Science.gov (United States)
Jain, Kavita
2009-02-01
We study the adaptation dynamics of an initially maladapted population evolving via the elementary processes of mutation and selection. The evolution occurs on rugged fitness landscapes which are defined on the multi-dimensional genotypic space and have many local peaks separated by low fitness valleys. We mainly focus on the Eigen's model that describes the deterministic dynamics of an infinite number of self-replicating molecules. In the stationary state, for small mutation rates such a population forms a {\\it quasispecies} which consists of the fittest genotype and its closely related mutants. The quasispecies dynamics on rugged fitness landscape follow a punctuated (or step-like) pattern in which a population jumps from a low fitness peak to a higher one, stays there for a considerable time before shifting the peak again and eventually reaches the global maximum of the fitness landscape. We calculate exactly several properties of this dynamical process within a simplified version of the quasispecies model.
18. A general hybrid radiation transport scheme for star formation simulations on an adaptive grid
Energy Technology Data Exchange (ETDEWEB)
Klassen, Mikhail; Pudritz, Ralph E. [Department of Physics and Astronomy, McMaster University 1280 Main Street W, Hamilton, ON L8S 4M1 (Canada); Kuiper, Rolf [Max Planck Institute for Astronomy Königstuhl 17, D-69117 Heidelberg (Germany); Peters, Thomas [Institut für Computergestützte Wissenschaften, Universität Zürich Winterthurerstrasse 190, CH-8057 Zürich (Switzerland); Banerjee, Robi; Buntemeyer, Lars, E-mail: [email protected] [Hamburger Sternwarte, Universität Hamburg Gojenbergsweg 112, D-21029 Hamburg (Germany)
2014-12-10
19. A General Hybrid Radiation Transport Scheme for Star Formation Simulations on an Adaptive Grid
Science.gov (United States)
Klassen, Mikhail; Kuiper, Rolf; Pudritz, Ralph E.; Peters, Thomas; Banerjee, Robi; Buntemeyer, Lars
2014-12-01
20. Convergence across a continent: adaptive diversification in a recent radiation of Australian lizards.
Science.gov (United States)
Blom, Mozes P K; Horner, Paul; Moritz, Craig
2016-06-15
Recent radiations are important to evolutionary biologists, because they provide an opportunity to study the mechanisms that link micro- and macroevolution. The role of ecological speciation during adaptive radiation has been intensively studied, but radiations can arise from a diversity of evolutionary processes; in particular, on large continental landmasses where allopatric speciation might frequently precede ecological differentiation. It is therefore important to establish a phylogenetic and ecological framework for recent continental-scale radiations that are species-rich and ecologically diverse. Here, we use a genomic (approx. 1 200 loci, exon capture) approach to fit branch lengths on a summary-coalescent species tree and generate a time-calibrated phylogeny for a recent and ecologically diverse radiation of Australian scincid lizards; the genus Cryptoblepharus We then combine the phylogeny with a comprehensive phenotypic dataset for over 800 individuals across the 26 species, and use comparative methods to test whether habitat specialization can explain current patterns of phenotypic variation in ecologically relevant traits. We find significant differences in morphology between species that occur in distinct environments and convergence in ecomorphology with repeated habitat shifts across the continent. These results suggest that isolated analogous habitats have provided parallel ecological opportunity and have repeatedly promoted adaptive diversification. By contrast, speciation processes within the same habitat have resulted in distinct lineages with relatively limited morphological variation. Overall, our study illustrates how alternative diversification processes might have jointly stimulated species proliferation across the continent and generated a remarkably diverse group of Australian lizards. © 2016 The Author(s).
1. European upper mantle tomography: adaptively parameterized models
Science.gov (United States)
Schäfer, J.; Boschi, L.
2009-04-01
We have devised a new algorithm for upper-mantle surface-wave tomography based on adaptive parameterization: i.e. the size of each parameterization pixel depends on the local density of seismic data coverage. The advantage in using this kind of parameterization is that a high resolution can be achieved in regions with dense data coverage while a lower (and cheaper) resolution is kept in regions with low coverage. This way, parameterization is everywhere optimal, both in terms of its computational cost, and of model resolution. This is especially important for data sets with inhomogenous data coverage, as it is usually the case for global seismic databases. The data set we use has an especially good coverage around Switzerland and over central Europe. We focus on periods from 35s to 150s. The final goal of the project is to determine a new model of seismic velocities for the upper mantle underlying Europe and the Mediterranean Basin, of resolution higher than what is currently found in the literature. Our inversions involve regularization via norm and roughness minimization, and this in turn requires that discrete norm and roughness operators associated with our adaptive grid be precisely defined. The discretization of the roughness damping operator in the case of adaptive parameterizations is not as trivial as it is for the uniform ones; important complications arise from the significant lateral variations in the size of pixels. We chose to first define the roughness operator in a spherical harmonic framework, and subsequently translate it to discrete pixels via a linear transformation. Since the smallest pixels we allow in our parameterization have a size of 0.625 °, the spherical-harmonic roughness operator has to be defined up to harmonic degree 899, corresponding to 810.000 harmonic coefficients. This results in considerable computational costs: we conduct the harmonic-pixel transformations on a small Beowulf cluster. We validate our implementation of adaptive
2. A review of segmentation and deformable registration methods applied to adaptive cervical cancer radiation therapy treatment planning.
Science.gov (United States)
Ghose, Soumya; Holloway, Lois; Lim, Karen; Chan, Philip; Veera, Jacqueline; Vinod, Shalini K; Liney, Gary; Greer, Peter B; Dowling, Jason
2015-06-01
3. Antarctic notothenioid fishes: genomic resources and strategies for analyzing an adaptive radiation.
Science.gov (United States)
Detrich, H W; Amemiya, Chris T
2010-12-01
The perciform suborder Notothenoidei provides a compelling opportunity to study the adaptive radiation of a marine species-flock in the cold Southern Ocean that surrounds Antarctica. To facilitate genome-level studies of the diversification of these fishes, we present estimates of the genome sizes of 11 Antarctic species and describe the production of high-quality bacterial artificial chromosome (BAC) libraries for two, the red-blooded notothen Notothenia coriiceps and the white-blooded icefish Chaenocephalus aceratus. Our results indicate that evolution of phylogenetically derived notothenioid families (e.g., the crown group Channichthyidae [icefishes]), was accompanied by genome expansion. Six species from the basal family Nototheniidae had C-values between 0.98 and 1.20 pg, a range that is consistent with the genome sizes of proposed outgroups (e.g., percids) of the notothenioid suborder. In contrast, four icefishes had C-values in the range 1.66-1.83 pg. The BAC libraries VMRC-19 (N. coriiceps) and VMRC-21 (C. aceratus) comprise 12× and 10× coverage of the respective genomes and have average insert sizes of 138 and 168 kb. Paired BAC-end reads representing ∼0.1% of each genome showed that the repetitive element landscapes of the two genomes (13.4% of the N. coriiceps genome and 14.5% for C. aceratus) were similar. The availability of these high-quality and well-characterized BAC libraries sets the stage for targeted genomic analyses of the unusual anatomical and physiological adaptations of the notothenioids, some of which mimic human diseases. Here we consider the evolution of secondary pelagicism by various taxa of the group and illustrate the utility of Antarctic icefishes as an evolutionary-mutant model of human osteopenia (low-mineral density of bones).
4. Possible human impacts on adaptive radiation: beak size bimodality in Darwin's finches.
Science.gov (United States)
Hendry, Andrew P; Grant, Peter R; Rosemary Grant, B; Ford, Hugh A; Brewer, Mark J; Podos, Jeffrey
2006-08-01
Adaptive radiation is facilitated by a rugged adaptive landscape, where fitness peaks correspond to trait values that enhance the use of distinct resources. Different species are thought to occupy the different peaks, with hybrids falling into low-fitness valleys between them. We hypothesize that human activities can smooth adaptive landscapes, increase hybrid fitness and hamper evolutionary diversification. We investigated this possibility by analysing beak size data for 1755 Geospiza fortis measured between 1964 and 2005 on the island of Santa Cruz, Galápagos. Some populations of this species can display a resource-based bimodality in beak size, which mirrors the greater beak size differences among species. We first show that an historically bimodal population at one site, Academy Bay, has lost this property in concert with a marked increase in local human population density. We next show that a nearby site with lower human impacts, El Garrapatero, currently manifests strong bimodality. This comparison suggests that bimodality can persist when human densities are low (Academy Bay in the past, El Garrapatero in the present), but not when they are high (Academy Bay in the present). Human activities may negatively impact diversification in 'young' adaptive radiations, perhaps by altering adaptive landscapes.
5. Seasonal radiative modeling of Titan's stratosphere
Science.gov (United States)
Bézard, Bruno; Vinatier, Sandrine; Achterberg, Richard
2016-10-01
We have developed a seasonal radiative model of Titan's stratosphere to investigate the time variation of stratospheric temperatures in the 10-3 - 5 mbar range as observed by the Cassini/CIRS spectrometer. The model incorporates gas and aerosol vertical profiles derived from Cassini/CIRS spectra to calculate the heating and cooling rate profiles as a function of time and latitude. In the equatorial region, the radiative equilibrium profile is warmer than the observed one. Adding adiabatic cooling in the energy equation, with a vertical velocity profile decreasing with depth and having w ≈ 0.4 mm sec-1 at 1 mbar, allows us to reproduce the observed profile. The model predicts a 5 K decrease at 1 mbar between 2008 and 2016 as a result of orbit eccentricity, in relatively good agreement with the observations. At other latitudes, as expected, the radiative model predicts seasonal variations of temperature larger than observed, pointing to latitudinal redistribution of heat by dynamics. Vertical velocities seasonally varying between -0.4 and 1.2 mm sec-1 at 1 mbar provide adiabatic cooling and heating adequate to reproduce the time variation of 1-mbar temperatures from 2005 to 2016 at 30°N and S. The model is also used to investigate the role of the strong compositional changes observed at high southern latitudes after equinox in the concomitant rapid cooling of the stratosphere.
6. Evaluation of Online/Offline Image Guidance/Adaptation Approaches for Prostate Cancer Radiation Therapy
Energy Technology Data Exchange (ETDEWEB)
Qin, An [Department of Radiation Oncology, Beaumont Health System, Royal Oak, Michigan (United States); Sun, Ying [Department of Radiotherapy, Cancer Center, Sun Yat-sen University, Guangzhou (China); Liang, Jian [Department of Radiation Oncology, Beaumont Health System, Royal Oak, Michigan (United States); Yan, Di, E-mail: [email protected] [Department of Radiation Oncology, Beaumont Health System, Royal Oak, Michigan (United States)
2015-04-01
7. [Adaptation reactions of rat blood exposed to low intensity electromagnetic radiation].
Science.gov (United States)
Krylov, V N; Deriugina, A V
2010-06-01
It is carried out research of action low-intensive electromagnetic radiations--low-intensive laser radiation and radiations of the highest frequency on normal animals and at modelling the stress-reaction, caused by introduction of adrenaline. Absence of effects of system of blood is noted at action low-intensive electromagnetic radiations on normal an organism and them correction action on alteration an organism, shown in restoration of the broken parameters--leukocyte the blood count, electrophoretic mobility of erythrocytes and phospholipide's structure of their membranes.
8. Principles of the radiative ablation modeling
Science.gov (United States)
Saillard, Yves; Arnault, Philippe; Silvert, Virginie
2010-12-01
Indirectly driven inertial confinement fusion (ICF) rests on the setting up of a radiation temperature within a laser cavity and on the optimization of the capsule implosion ablated by this radiation. In both circumstances, the ablation of an optically thick medium is at work. The nonlinear radiation conduction equations that describe this phenomenon admit different kinds of solutions called generically Marshak waves. In this paper, a completely analytic model is proposed to describe the ablation in the subsonic regime relevant to ICF experiments. This model approximates the flow by a deflagrationlike structure where Hugoniot relations are used in the stationary part from the ablation front up to the isothermal sonic Chapman-Jouguet point and where the unstationary expansion from the sonic point up to the external boundary is assumed quasi-isothermal. It uses power law matter properties. It can also accommodate arbitrary boundary conditions provided the ablation wave stays very subsonic and the surface temperature does not vary too quickly. These requirements are often met in realistic situations. Interestingly, the ablated mass rate, the ablation pressure, and the absorbed radiative energy depend on the time history of the surface temperature, not only on the instantaneous temperature values. The results compare very well with self-similar solutions and with numerical simulations obtained by hydrodynamic code. This analytic model gives insight into the physical processes involved in the ablation and is helpful for optimization and sensitivity studies in many situations of interest: radiation temperature within a laser cavity, acceleration of finite size medium, and ICF capsule implosion, for instance.
9. Induction of the Adaptive Response in Mice Exposed to He-Ne Laser and X-Ray Radiation.
Science.gov (United States)
Zaichkina, S I; Dyukina, A R; Rozanova, O M; Simonova, N B; Romanchenko, S P; Sorokina, S S; Zakrzhevskaya, D T; Yusupov, V I; Bagratashvili, V N
2016-05-01
We studied the dose-dependent induction of in vivo adaptive response in the bone marrow and blood of mice exposed to low-intensity radiation of He-Ne laser (633 nm) and X-ray radiation by the severity of cytogenetic injury and intensity of ROS production, respectively. Induction of the adaptive response in mice preexposed to He-Ne laser and X-ray radiation depended on the adaptive dose and the interval between the adaptive and main doses and correlated with changes in ROS generation. The adaptive response after exposure to low-intensity ionizing and non-ionizing radiation was observed in the same dose range, which attests to similar mechanisms of its induction.
10. Inflation model selection meets dark radiation
Science.gov (United States)
Tram, Thomas; Vallance, Robert; Vennin, Vincent
2017-01-01
We investigate how inflation model selection is affected by the presence of additional free-streaming relativistic degrees of freedom, i.e. dark radiation. We perform a full Bayesian analysis of both inflation parameters and cosmological parameters taking reheating into account self-consistently. We compute the Bayesian evidence for a few representative inflation scenarios in both the standard ΛCDM model and an extension including dark radiation parametrised by its effective number of relativistic species Neff. Using a minimal dataset (Planck low-l polarisation, temperature power spectrum and lensing reconstruction), we find that the observational status of most inflationary models is unchanged. The exceptions are potentials such as power-law inflation that predict large values for the scalar spectral index that can only be realised when Neff is allowed to vary. Adding baryon acoustic oscillations data and the B-mode data from BICEP2/Keck makes power-law inflation disfavoured, while adding local measurements of the Hubble constant H0 makes power-law inflation slightly favoured compared to the best single-field plateau potentials. This illustrates how the dark radiation solution to the H0 tension would have deep consequences for inflation model selection.
11. Radiative torques: Analytical Model and Basic Properties
CERN Document Server
Lazarian, Alex
2007-01-01
We attempt to get a physical insight into grain alignment processes by studying basic properties of radiative torques (RATs). For this purpose we consider a simple toy model of a helical grain that reproduces well the basic features of RATs. The model grain consists of a spheroidal body with a mirror attached at an angle to it. Being very simple, the model allows analytical description of RATs that act upon it. We show a good correspondence of RATs obtained for this model and those of irregular grains calculated by DDSCAT. Our analysis of the role of different torque components for grain alignment reveals that one of the three RAT components does not affect the alignment, but induces only for grain precession. The other two components provide a generic alignment with grain long axes perpendicular to the radiation direction, if the radiation dominates the grain precession, and perpendicular to magnetic field, otherwise. We study a self-similar scaling of RATs as a function of $\\lambda/a_{eff}$. We show that th...
Directory of Open Access Journals (Sweden)
I. Foyo-Moreno
2007-07-01
Full Text Available In this work we adapt an empirical model to estimate ultraviolet erythemal irradiance (UVER using experimental measurements carried out at seven stations in Spain during four years (2000–2003. The measurements were taken in the framework of the Spanish UVB radiometric network operated and maintained by the Spanish Meteorological Institute. The UVER observations are recorded as half hour average values. The model is valid for all-sky conditions, estimating UVER from the ozone columnar content and parameters usually registered in radiometric networks, such as global broadband hemispherical transmittance and optical air mass. One data set was used to develop the model and another independent set was used to validate it. The model provides satisfactory results, with low mean bias error (MBE for all stations. In fact, MBEs are less than 4% and root mean square errors (RMSE are below 18% (except for one location. The model has also been evaluated to estimate the UV index. The percentage of cases with differences of 0 UVI units is in the range of 61.1% to 72.0%, while the percentage of cases with differences of ±1 UVI unit covers the range of 95.6% to 99.2%. This result confirms the applicability of the model to estimate UVER irradiance and the UV index at those locations in the Iberian Peninsula where there are no UV radiation measurements.
13. A 5-Year Investigation of Children's Adaptive Functioning Following Conformal Radiation Therapy for Localized Ependymoma
Energy Technology Data Exchange (ETDEWEB)
Netson, Kelli L.; Conklin, Heather M. [Department of Psychology, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Wu Shengjie; Xiong Xiaoping [Department of Biostatistics, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Merchant, Thomas E., E-mail: [email protected] [Division of Radiation Oncology, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States)
2012-09-01
Purpose: Conformal and intensity modulated radiation therapies have the potential to preserve cognitive outcomes in children with ependymoma; however, functional behavior remains uninvestigated. This longitudinal investigation prospectively examined intelligence quotient (IQ) and adaptive functioning during the first 5 years after irradiation in children diagnosed with ependymoma. Methods and Materials: The study cohort consisted of 123 children with intracranial ependymoma. Mean age at irradiation was 4.60 years (95% confidence interval [CI], 3.85-5.35). Serial neurocognitive evaluations, including an age-appropriate IQ measure and the Vineland Adaptive Behavior Scales (VABS), were completed before irradiation, 6 months after treatment, and annually for 5 years. A total of 579 neurocognitive evaluations were included in these analyses. Results: Baseline IQ and VABS were below normative means (P<.05), although within the average range. Linear mixed models revealed stable IQ and VABS across the follow-up period, except for the VABS Communication Index, which declined significantly (P=.015). Annual change in IQ (-.04 points) did not correlate with annual change in VABS (-.90 to +.44 points). Clinical factors associated with poorer baseline performance (P<.05) included preirradiation chemotherapy, cerebrospinal fluid shunt placement, number and extent of surgical resections, and younger age at treatment. No clinical factors significantly affected the rate of change in scores. Conclusions: Conformal and intensity modulated radiation therapies provided relative sparing of functional outcomes including IQ and adaptive behaviors, even in very young children. Communication skills remained vulnerable and should be the target of preventive and rehabilitative interventions.
14. Extended Higgs sectors in radiative neutrino models
Directory of Open Access Journals (Sweden)
Oleg Antipin
2017-05-01
Full Text Available Testable Higgs partners may be sought within the extensions of the SM Higgs sector aimed at generating neutrino masses at the loop level. We study a viability of extended Higgs sectors for two selected models of radiative neutrino masses: a one-loop mass model, providing the Higgs partner within a real triplet scalar representation, and a three-loop mass model, providing it within its two-Higgs-doublet sector. The Higgs sector in the one-loop model may remain stable and perturbative up to the Planck scale, whereas the three-loop model calls for a UV completion around 106 GeV. Additional vector-like lepton and exotic scalar fields, which are required to close one- and three-loop neutrino-mass diagrams, play a decisive role for the testability of the respective models. We constrain the parameter space of these models using LHC bounds on diboson resonances.
15. Biologically based multistage modeling of radiation effects
Energy Technology Data Exchange (ETDEWEB)
William Hazelton; Suresh Moolgavkar; E. Georg Luebeck
2005-08-30
16. Adaptable Multivariate Calibration Models for Spectral Applications
Energy Technology Data Exchange (ETDEWEB)
THOMAS,EDWARD V.
1999-12-20
Multivariate calibration techniques have been used in a wide variety of spectroscopic situations. In many of these situations spectral variation can be partitioned into meaningful classes. For example, suppose that multiple spectra are obtained from each of a number of different objects wherein the level of the analyte of interest varies within each object over time. In such situations the total spectral variation observed across all measurements has two distinct general sources of variation: intra-object and inter-object. One might want to develop a global multivariate calibration model that predicts the analyte of interest accurately both within and across objects, including new objects not involved in developing the calibration model. However, this goal might be hard to realize if the inter-object spectral variation is complex and difficult to model. If the intra-object spectral variation is consistent across objects, an effective alternative approach might be to develop a generic intra-object model that can be adapted to each object separately. This paper contains recommendations for experimental protocols and data analysis in such situations. The approach is illustrated with an example involving the noninvasive measurement of glucose using near-infrared reflectance spectroscopy. Extensions to calibration maintenance and calibration transfer are discussed.
Energy Technology Data Exchange (ETDEWEB)
Sanchez Mazon, J.; Raba Diez, J. I.; Vazquez Rodriguez, J. a.; Pacheco Baldor, M. T.; Mendiguren Santiago, M. A.; Menendez Garcia, J. C.
2011-07-01
The previous updates are a form of adaptive radiation that can be used to account for changes in the size, shape and location of both the tumor and healthy tissue. Are especially useful in the case of lung cancer which typically is associated with significant anatomical changes due to the response to treatment.In the present study, the variation in tumor volume and dosimetric effects from a new CT and replanning during the course of treatment in patients with lung cancer.
18. Solar Radiation-Associated Adaptive SNP Genetic Differentiation in Wild Emmer Wheat, Triticum dicoccoides
Science.gov (United States)
Ren, Jing; Chen, Liang; Jin, Xiaoli; Zhang, Miaomiao; You, Frank M.; Wang, Jirui; Frenkel, Vladimir; Yin, Xuegui; Nevo, Eviatar; Sun, Dongfa; Luo, Ming-Cheng; Peng, Junhua
2017-01-01
19. Phylogenomics Reveals Three Sources of Adaptive Variation during a Rapid Radiation.
Directory of Open Access Journals (Sweden)
James B Pease
2016-02-01
Full Text Available Speciation events often occur in rapid bursts of diversification, but the ecological and genetic factors that promote these radiations are still much debated. Using whole transcriptomes from all 13 species in the ecologically and reproductively diverse wild tomato clade (Solanum sect. Lycopersicon, we infer the species phylogeny and patterns of genetic diversity in this group. Despite widespread phylogenetic discordance due to the sorting of ancestral variation, we date the origin of this radiation to approximately 2.5 million years ago and find evidence for at least three sources of adaptive genetic variation that fuel diversification. First, we detect introgression both historically between early-branching lineages and recently between individual populations, at specific loci whose functions indicate likely adaptive benefits. Second, we find evidence of lineage-specific de novo evolution for many genes, including loci involved in the production of red fruit color. Finally, using a "PhyloGWAS" approach, we detect environment-specific sorting of ancestral variation among populations that come from different species but share common environmental conditions. Estimated across the whole clade, small but substantial and approximately equal fractions of the euchromatic portion of the genome are inferred to contribute to each of these three sources of adaptive genetic variation. These results indicate that multiple genetic sources can promote rapid diversification and speciation in response to new ecological opportunity, in agreement with our emerging phylogenomic understanding of the complexity of both ancient and recent species radiations.
20. An Optimal Control Modification to Model-Reference Adaptive Control for Fast Adaptation
Science.gov (United States)
Nguyen, Nhan T.; Krishnakumar, Kalmanje; Boskovic, Jovan
2008-01-01
1. new model for solar radiation estimation from measured air ...
African Journals Online (AJOL)
HOD
Nigerian Meteorological Agency (NIMET) were used as inputs to the ANFIS model and monthly mean global solar radiation was ... models were used to predict solar radiation in Nigeria by. [12-15]. .... calculate them as total output [32] and [34].
2. A theoretical approach to room acoustic simulations based on a radiative transfer model
DEFF Research Database (Denmark)
Ruiz-Navarro, Juan-Miguel; Jacobsen, Finn; Escolano, José
2010-01-01
A theoretical approach to room acoustic simulations based on a radiative transfer model is developed by adapting the classical radiative transfer theory from optics to acoustics. The proposed acoustic radiative transfer model expands classical geometrical room acoustic modeling algorithms...... by incorporating a propagation medium that absorbs and scatters radiation, handling both diffuse and non-diffuse reflections on boundaries and objects in the room. The main scope of this model is to provide a proper foundation for a wide number of room acoustic simulation models, in order to establish and unify...... their principles. It is shown that this room acoustic modeling technique establishes the basis of two recently proposed algorithms, the acoustic diffusion equation and the room acoustic rendering equation. Both methods are derived in detail using an analytical approximation and a simplified integral equation...
Science.gov (United States)
Zhou, H.; Randers-Pehrson, G.; Waldren, C. A.; Hei, T. K.
2004-01-01
CERN Document Server
Pawlik, Andreas H; Vecchia, Claudio Dalla
2015-01-01
We present a suite of cosmological radiation-hydrodynamical simulations of the assembly of galaxies driving the reionization of the intergalactic medium (IGM) at z >~ 6. The simulations account for the hydrodynamical feedback from photoionization heating and the explosion of massive stars as supernovae (SNe). Our reference simulation, which was carried out in a box of size 25 comoving Mpc/h using 2 x 512^3 particles, produces a reasonable reionization history and matches the observed UV luminosity function of galaxies. Simulations with different box sizes and resolutions are used to investigate numerical convergence, and simulations in which either SNe or photoionization heating or both are turned off, are used to investigate the role of feedback from star formation. Ionizing radiation is treated using accurate radiative transfer at the high spatially adaptive resolution at which the hydrodynamics is carried out. SN feedback strongly reduces the star formation rates (SFRs) over nearly the full mass range of s...
5. Can the adaptive response to ionizing radiation detect by the cytokinesis-blocked micronuclei assay?
Energy Technology Data Exchange (ETDEWEB)
Kwon, Hee-Kyung; Lee, Hye-Jin; Park, Mi-Young [Korea institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)] (and others)
2006-07-01
Many studies have been performed to assess the development and application of potentially useful biodosimetry. At present, although chromosome dicentric assay is a sensitive method for dose estimation, it is laborious and requires enough experience for estimation. Therefore, we need an alternative cytogenetic dosimetry to estimate the absorbed dose of victims after low dose exposure such as radiation accidents in hospital workers and workers of radiation related facilities1. An alternative and simple cytogenetic technique is the measurement of the micronucleus frequency in cultured human lymphocytes. The reliability of conventional micronucleus (MN) assays is diminished owing to the inclusion of non-dividing cells in the estimate, but this problem has been overcome by the development of the cytokinesis-blocked (CB) MN assay. The reliable and ease assays of the cytokinesis blocked-approach are obvious advantages in biological monitoring, but there are no developed recognizable and reliable techniques for biological dosimetry of a low dose exposure until recently. Adaptive response is important in determining the biological responses at low doses of radiation and has the potential to impact the shape of the dose-response relationship. We analyzed the frequency of both spontaneous and in vitro {sup 137}Cs {gamma}-rays-induced MNs in the low dose radiation-exposed workers to estimate the cytokinesisblocked (CB) MN assay is proper assay or not as a screening the adaptive response.
Directory of Open Access Journals (Sweden)
Zhongrong Liu
2012-01-01
7. Adaptive planning using megavoltage fan-beam CT for radiation therapy with testicular shielding.
Science.gov (United States)
Yadav, Poonam; Kozak, Kevin; Tolakanahalli, Ranjini; Ramasubramanian, V; Paliwal, Bhudatt R; Welsh, James S; Rong, Yi
2012-01-01
8. Adaptive planning using megavoltage fan-beam CT for radiation therapy with testicular shielding
Energy Technology Data Exchange (ETDEWEB)
2012-07-01
9. Adaptive functioning of childhood brain tumor survivors following conformal radiation therapy.
Science.gov (United States)
Ashford, Jason M; Netson, Kelli L; Clark, Kellie N; Merchant, Thomas E; Santana, Victor M; Wu, Shengjie; Conklin, Heather M
2014-05-01
10. Theoretical Modelling of Sound Radiation from Plate
Science.gov (United States)
Zaman, I.; Rozlan, S. A. M.; Yusoff, A.; Madlan, M. A.; Chan, S. W.
2017-01-01
Recently the development of aerospace, automotive and building industries demands the use of lightweight materials such as thin plates. However, the plates can possibly add to significant vibration and sound radiation, which eventually lead to increased noise in the community. So, in this study, the fundamental concept of sound pressure radiated from a simply-supported thin plate (SSP) was analyzed using the derivation of mathematical equations and numerical simulation of ANSYS®. The solution to mathematical equations of sound radiated from a SSP was visualized using MATLAB®. The responses of sound pressure level were measured at far field as well as near field in the frequency range of 0-200 Hz. Result shows that there are four resonance frequencies; 12 Hz, 60 Hz, 106 Hz and 158 Hz were identified which represented by the total number of the peaks in the frequency response function graph. The outcome also indicates that the mathematical derivation correlated well with the simulation model of ANSYS® in which the error found is less than 10%. It can be concluded that the obtained model is reliable and can be applied for further analysis such as to reduce noise emitted from a vibrating thin plate.
11. International Space Station Radiation Shielding Model Development
Science.gov (United States)
Qualls, G. D.; Wilson, J. W.; Sandridge, C.; Cucinotta, F. A.; Nealy, J. E.; Heinbockel, J. H.; Hugger, C. P.; Verhage, J.; Anderson, B. M.; Atwell, W.
2001-01-01
The projected radiation levels within the International Space Station (ISS) have been criticized by the Aerospace Safety Advisory Panel in their report to the NASA Administrator. Methods for optimal reconfiguration and augmentation of the ISS shielding are now being developed. The initial steps are to develop reconfigurable and realistic radiation shield models of the ISS modules, develop computational procedures for the highly anisotropic radiation environment, and implement parametric and organizational optimization procedures. The targets of the redesign process are the crew quarters where the astronauts sleep and determining the effects of ISS shadow shielding of an astronaut in a spacesuit. The ISS model as developed will be reconfigurable to follow the ISS. Swapping internal equipment rack assemblies via location mapping tables will be one option for shield optimization. Lightweight shield augmentation materials will be optimally fit to crew quarter areas using parametric optimization procedures to minimize the augmentation shield mass. The optimization process is being integrated into the Intelligence Synthesis Environment s (ISE s) immersive simulation facility at the Langley Research Center and will rely on High Performance Computing and Communication (HPCC) for rapid evaluation of shield parameter gradients.
12. Global VTEC-modelling in near real-time based on space geodetic techniques, adapted B-spline expansions and Kalman-filtering including observations of the Sun's radiation
Science.gov (United States)
Börger, Klaus; Schmidt, Michael; Dettmering, Denise; Limberger, Marco; Erdogan, Eren; Seitz, Florian; Brandert, Sylvia; Görres, Barbara; Kersten, Wilhelm; Bothmer, Volker; Hinrichs, Johannes; Venzmer, Malte; Mrotzek, Niclas
2016-04-01
Today, the observations of space geodetic techniques are usually available with a rather low latency which applies to space missions observing the solar terrestrial environment, too. Therefore, we can use all these measurements in near real-time to compute and to provide ionosphere information, e.g. the vertical total electron content (VTEC). GSSAC and BGIC support a project aiming at a service for providing ionosphere information. This project is called OPTIMAP, meaning "Operational Tool for Ionosphere Mapping and Prediction"; the scientific work is mainly done by the German Geodetic Research Institute of the Technical University Munich (DGFI-TUM) and the Institute for Astrophysics of the University of Goettingen (IAG). The OPTIMAP strategy for providing ionosphere target quantities of high quality, such as VTEC or the electron density, includes mathematical approaches and tools allowing for the model adaptation to the real observational scenario as a significant improvement w.r.t. the traditional well-established methods. For example, OPTIMAP combines different observation types such as GNSS (GPS, GLONASS), Satellite Altimetry (Jason-2), DORIS as well as radio-occultation measurements (FORMOSAT#3/COSMIC). All these observations run into a Kalman-filter to compute global ionosphere maps, i.e. VTEC, for the current instant of time and as a forecast for a couple of subsequent days. Mathematically, the global VTEC is set up as a series expansion in terms of two-dimensional basis functions defined as tensor products of trigonometric B-splines for longitude and polynomial B-splines for latitude. Compared to the classical spherical harmonics, B-splines have a localizing character and, therefore, can handle an inhomogeneous data distribution properly. Finally, B-splines enable a so-called multi-resolution-representation (MRR) enabling the combination of global and regional modelling approaches. In addition to the geodetic measurements, Sun observations are pre
13. A Radiative Transport Model for Blazars
Science.gov (United States)
Lewis, Tiffany; Justin, Finke; Becker, Peter A.
2017-01-01
Blazars are observed across the electromagnetic spectrum, often with strong variability throughout. The underlying electron distribution associated with the observed emission is typically not computed from first principles. We start from first-principles to build up a transport model, whose solution is the electron distribution, rather than assuming a convenient functional form. Our analytical transport model considers shock acceleration, adiabatic expansion, stochastic acceleration, Bohm diffusion, and synchrotron radiation. We use this solution to generate predictions for the X-ray spectrum and time lags, and compare the results with data products from BeppoSAX observations of X-ray flares from Mrk 421. This new self-consistent model provides an unprecedented view into the jet physics at play in this source, especially the strength of the shock and stochastic acceleration components and the size of the acceleration region.More recently, we augmented the transport model to incorporate Compton scattering, including Klein-Nishina effects. In this case, an analytical solution cannot be derived, and therefore we obtain the steady-state electron distribution computationally. We compare the resulting radiation spectrum with multi-wavelength data for 3C 279. We show that our new Compton + synchrotron blazar model is the first to successfully fit the FermiLAT gamma-ray data for this source based on a first-principles physical calculation.
14. Using patient-specific phantoms to evaluate deformable image registration algorithms for adaptive radiation therapy.
Science.gov (United States)
Stanley, Nick; Glide-Hurst, Carri; Kim, Jinkoo; Adams, Jeffrey; Li, Shunshan; Wen, Ning; Chetty, Indrin J; Zhong, Hualiang
2013-11-04
The quality of adaptive treatment planning depends on the accuracy of its underlying deformable image registration (DIR). The purpose of this study is to evaluate the performance of two DIR algorithms, B-spline-based deformable multipass (DMP) and deformable demons (Demons), implemented in a commercial software package. Evaluations were conducted using both computational and physical deformable phantoms. Based on a finite element method (FEM), a total of 11 computational models were developed from a set of CT images acquired from four lung and one prostate cancer patients. FEM generated displacement vector fields (DVF) were used to construct the lung and prostate image phantoms. Based on a fast-Fourier transform technique, image noise power spectrum was incorporated into the prostate image phantoms to create simulated CBCT images. The FEM-DVF served as a gold standard for verification of the two registration algorithms performed on these phantoms. The registration algorithms were also evaluated at the homologous points quantified in the CT images of a physical lung phantom. The results indicated that the mean errors of the DMP algorithm were in the range of 1.0 ~ 3.1 mm for the computational phantoms and 1.9 mm for the physical lung phantom. For the computational prostate phantoms, the corresponding mean error was 1.0-1.9 mm in the prostate, 1.9-2.4mm in the rectum, and 1.8-2.1 mm over the entire patient body. Sinusoidal errors induced by B-spline interpolations were observed in all the displacement profiles of the DMP registrations. Regions of large displacements were observed to have more registration errors. Patient-specific FEM models have been developed to evaluate the DIR algorithms implemented in the commercial software package. It has been found that the accuracy of these algorithms is patient dependent and related to various factors including tissue deformation magnitudes and image intensity gradients across the regions of interest. This may suggest that
15. The effect of population structure on the adaptive radiation of microbial populations evolving in spatially structured environments
NARCIS (Netherlands)
Habets, M.G.J.L.; Rozen, D.; Hoekstra, R.F.; Visser, de J.A.G.M.
2006-01-01
Spatial structure is thought to be an important factor influencing the emergence and maintenance of genetic diversity. Previous studies have demonstrated that environmental heterogeneity, provided by spatial structure, leads to adaptive radiation of populations. In the present study, we investigate
16. Adaptation of the Neural Network Recognition System of the Helicopter on Its Acoustic Radiation to the Flight Speed
Directory of Open Access Journals (Sweden)
V. K. Hohlov
2015-01-01
Full Text Available The article concerns the adaptation of a neural tract that recognizes a helicopter from the aerodynamic and ground objects by its acoustic radiation to the helicopter flight speed. It uses non-centered informative signs-indications of estimating signal spectra, which correspond to the local extremes (maximums and minimums of the power spectrum of input signal and have the greatest information when differentiating the helicopter signals from those of tracked vehicles. The article gives justification to the principle of the neural network (NN adaptation and adaptation block structure, which solves problems of blade passage frequency estimation when capturing the object and track it when tracking a target, as well as forming a signal to control the resonant filter parameters of the selection block of informative signs. To create the discriminatory characteristics of the discriminator are used autoregressive statistical characteristics of the quadrature components of signal, obtained through the discrete Hilbert Converter (DGC that perforMathematical modeling of the tracking meter using the helicopter signals obtained in real conditions is performed. The article gives estimates of the tracking parameter when using a tracking meter with DGC by sequential records of realized acoustic noise of the helicopter. It also shows a block-diagram of the adaptive NN. The scientific novelty of the work is that providing the invariance of used informative sign, the counts of local extremes of power spectral density (PSD to changes in the helicopter flight speed is reached due to adding the NN structure and adaptation block, which is implemented as a meter to track the apparent passage frequency of the helicopter rotor blades using its relationship with a function of the autoregressive acoustic signal of the helicopter.Specialized literature proposes solutions based on the use of training classifiers with different parametric methods of spectral representations
17. The ADAPT design model: towards instructional control of transfer
NARCIS (Netherlands)
Jelsma, Otto; Merrienboer, van Jeroen J.G.; Bijlstra, Jim P.
1990-01-01
This paper presents a detailed description of the ADAPT (Apply Delayed Automatization for Positive Transfer) design model. ADAPT is based upon production system models of learning and provides guidelines for developing instructional systems that offer transfer of leamed skills. The model suggests th
18. Androgen Induces Adaptation to Oxidative Stress in Prostate Cancer: Implications for Treatment with Radiation Therapy
Directory of Open Access Journals (Sweden)
Jehonathan H. Pinthus
2007-01-01
19. A theoretical adaptive model of thermal comfort - Adaptive Predicted Mean Vote (aPMV)
Energy Technology Data Exchange (ETDEWEB)
Yao, Runming [School of Construction Management and Engineering, The University of Reading (United Kingdom); Faculty of Urban Construction and Environmental Engineering, Chongqing University (China); Li, Baizhan [Key Laboratory of the Three Gorges Reservoir Region' s Eco-Environment (Ministry of Education), Chongqing University (China); Faculty of Urban Construction and Environmental Engineering, Chongqing University (China); Liu, Jing [School of Construction Management and Engineering, The University of Reading (United Kingdom)
2009-10-15
This paper presents in detail a theoretical adaptive model of thermal comfort based on the ''Black Box'' theory, taking into account factors such as culture, climate, social, psychological and behavioural adaptations, which have an impact on the senses used to detect thermal comfort. The model is called the Adaptive Predicted Mean Vote (aPMV) model. The aPMV model explains, by applying the cybernetics concept, the phenomena that the Predicted Mean Vote (PMV) is greater than the Actual Mean Vote (AMV) in free-running buildings, which has been revealed by many researchers in field studies. An Adaptive coefficient ({lambda}) representing the adaptive factors that affect the sense of thermal comfort has been proposed. The empirical coefficients in warm and cool conditions for the Chongqing area in China have been derived by applying the least square method to the monitored onsite environmental data and the thermal comfort survey results. (author)
20. Inflation Model Selection meets Dark Radiation
CERN Document Server
Tram, Thomas; Vennin, Vincent
2016-01-01
We investigate how inflation model selection is affected by the presence of additional free-streaming relativistic degrees of freedom, i.e. dark radiation. We perform a full Bayesian analysis of both inflation parameters and cosmological parameters taking reheating into account self-consistently. We compute the Bayesian evidence for a few representative inflation scenarios in both the standard $\\Lambda\\mathrm{CDM}$ model and an extension including dark radiation parametrised by its effective number of relativistic species $N_\\mathrm{eff}$. We find that the observational status of most inflationary models is unchanged, with the exception of potentials such as power-law inflation that predict a value for the scalar spectral index that is too large in $\\Lambda\\mathrm{CDM}$ but which can be accommodated when $N_\\mathrm{eff}$ is allowed to vary. In this case, cosmic microwave background data indicate that power-law inflation is one of the best models together with plateau potentials. However, contrary to plateau p...
1. Solar radiation practical modeling for renewable energy applications
CERN Document Server
Myers, Daryl Ronald
2013-01-01
Written by a leading scientist with over 35 years of experience working at the National Renewable Energy Laboratory (NREL), Solar Radiation: Practical Modeling for Renewable Energy Applications brings together the most widely used, easily implemented concepts and models for estimating broadband and spectral solar radiation data. The author addresses various technical and practical questions about the accuracy of solar radiation measurements and modeling. While the focus is on engineering models and results, the book does review the fundamentals of solar radiation modeling and solar radiation m
2. Adaptive Radiation Therapy for Postprostatectomy Patients Using Real-Time Electromagnetic Target Motion Tracking During External Beam Radiation Therapy
Energy Technology Data Exchange (ETDEWEB)
Zhu, Mingyao [Department of Radiation Oncology, Washington University School of Medicine, Saint Louis, Missouri (United States); Bharat, Shyam [Philips Research North America, Briarcliff Manor, New York (United States); Michalski, Jeff M.; Gay, Hiram A. [Department of Radiation Oncology, Washington University School of Medicine, Saint Louis, Missouri (United States); Hou, Wei-Hsien [St Louis University School of Medicine, St Louis, Missouri (United States); Parikh, Parag J., E-mail: [email protected] [Department of Radiation Oncology, Washington University School of Medicine, Saint Louis, Missouri (United States)
2013-03-15
3. Adaptive radiation therapy for postprostatectomy patients using real-time electromagnetic target motion tracking during external beam radiation therapy.
Science.gov (United States)
Zhu, Mingyao; Bharat, Shyam; Michalski, Jeff M; Gay, Hiram A; Hou, Wei-Hsien; Parikh, Parag J
2013-03-15
4. A 5-year investigation of children's adaptive functioning following conformal radiation therapy for localized ependymoma.
Science.gov (United States)
Netson, Kelli L; Conklin, Heather M; Wu, Shengjie; Xiong, Xiaoping; Merchant, Thomas E
2012-09-01
Science.gov (United States)
Joy, Jeffrey B; Crespi, Bernard J
2007-04-01
Speciation of plant-feeding insects is typically associated with host-plant shifts, with subsequent divergent selection and adaptation to the ecological conditions associated with the new plant. However, a few insect groups have apparently undergone speciation while remaining on the same host-plant species, and such radiations may provide novel insights into the causes of adaptive radiation. We used mitochondrial and nuclear DNA to infer a phylogeny for 14 species of gall-inducing Asphondylia flies (Diptera: Cecidomyiidae) found on Larrea tridentata (creosote bush), which have been considered to be monophyletic based on morphological evidence. Our phylogenetic analyses provide strong support for extensive within-host plant speciation in this group, and it demonstrates that diversification has involved numerous shifts between different plant organs (leaves, buds, flowers, and stems) of the same host-plant species. Within-plant speciation of Asphondylia is thus apparently facilitated by the opportunity to partition the plant ecologically. One clade exhibits temporal isolation among species, which may have facilitated divergence via allochronic shifts. Using a novel method based on Bayesian reconstruction, we show that the rate of change in an ecomorphological trait, ovipositor length, was significantly higher along branches with inferred shifts between host-plant organs than along branches without such shifts. This finding suggests that Larrea gall midges exhibit close morphological adaptation to specific host-plant parts, which may mediate ecological transitions via disruptive selection.
6. Adaptive radiation in extremophilic Dorvilleidae (Annelida): diversification of a single colonizer or multiple independent lineages?
Science.gov (United States)
Thornhill, Daniel J; Struck, Torsten H; Ebbe, Brigitte; Lee, Raymond W; Mendoza, Guillermo F; Levin, Lisa A; Halanych, Kenneth M
2012-08-01
7. Survey of current situation in radiation belt modeling
Science.gov (United States)
Fung, Shing F.
2004-01-01
8. A 331 WIMPy dark radiation model
Energy Technology Data Exchange (ETDEWEB)
Kelso, Chris [University of Utah, Department of Physics and Astronomy, Salt Lake City, UT (United States); Pires, C.A. de S.; Rodrigues da Silva, P.S. [Universidade Federal da Paraiba, Departamento de Fisica, Caixa Postal 5008, Joao Pessoa, PB (Brazil); Profumo, Stefano; Queiroz, Farinaldo S. [University of California, Department of Physics and Santa Cruz Institute for Particle Physics, Santa Cruz, CA (United States)
2014-03-15
Recent observations suggest that the number of relativistic degrees of freedom in the early universe might exceed what is predicted in the standard cosmological model. If even a small, percent-level fraction of dark matter particles are produced relativistically, they could mimic the effect of an extra realistic species at matter-radiation equality while obeying BBN, CMB and Structure Formation bounds. We show that this scenario is quite naturally realized with a weak-scale dark matter particle and a high-scale ''mother'' particle within a well-motivated 3-3-1 gauge model, which is particularly interesting for being consistent with electroweak precision measurements, with recent LHC results, and for offering a convincing explanation for the number of generations in the Standard Model. (orig.)
9. GAMMA-RAY BURST DYNAMICS AND AFTERGLOW RADIATION FROM ADAPTIVE MESH REFINEMENT, SPECIAL RELATIVISTIC HYDRODYNAMIC SIMULATIONS
Energy Technology Data Exchange (ETDEWEB)
De Colle, Fabio; Ramirez-Ruiz, Enrico [Astronomy and Astrophysics Department, University of California, Santa Cruz, CA 95064 (United States); Granot, Jonathan [Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel); Lopez-Camara, Diego, E-mail: [email protected] [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Ap. 70-543, 04510 D.F. (Mexico)
2012-02-20
We report on the development of Mezcal-SRHD, a new adaptive mesh refinement, special relativistic hydrodynamics (SRHD) code, developed with the aim of studying the highly relativistic flows in gamma-ray burst sources. The SRHD equations are solved using finite-volume conservative solvers, with second-order interpolation in space and time. The correct implementation of the algorithms is verified by one-dimensional (1D) and multi-dimensional tests. The code is then applied to study the propagation of 1D spherical impulsive blast waves expanding in a stratified medium with {rho}{proportional_to}r{sup -k}, bridging between the relativistic and Newtonian phases (which are described by the Blandford-McKee and Sedov-Taylor self-similar solutions, respectively), as well as to a two-dimensional (2D) cylindrically symmetric impulsive jet propagating in a constant density medium. It is shown that the deceleration to nonrelativistic speeds in one dimension occurs on scales significantly larger than the Sedov length. This transition is further delayed with respect to the Sedov length as the degree of stratification of the ambient medium is increased. This result, together with the scaling of position, Lorentz factor, and the shock velocity as a function of time and shock radius, is explained here using a simple analytical model based on energy conservation. The method used for calculating the afterglow radiation by post-processing the results of the simulations is described in detail. The light curves computed using the results of 1D numerical simulations during the relativistic stage correctly reproduce those calculated assuming the self-similar Blandford-McKee solution for the evolution of the flow. The jet dynamics from our 2D simulations and the resulting afterglow light curves, including the jet break, are in good agreement with those presented in previous works. Finally, we show how the details of the dynamics critically depend on properly resolving the structure of the
10. Gamma-Ray Burst Dynamics and Afterglow Radiation from Adaptive Mesh Refinement, Special Relativistic Hydrodynamic Simulations
Science.gov (United States)
De Colle, Fabio; Granot, Jonathan; López-Cámara, Diego; Ramirez-Ruiz, Enrico
2012-02-01
We report on the development of Mezcal-SRHD, a new adaptive mesh refinement, special relativistic hydrodynamics (SRHD) code, developed with the aim of studying the highly relativistic flows in gamma-ray burst sources. The SRHD equations are solved using finite-volume conservative solvers, with second-order interpolation in space and time. The correct implementation of the algorithms is verified by one-dimensional (1D) and multi-dimensional tests. The code is then applied to study the propagation of 1D spherical impulsive blast waves expanding in a stratified medium with ρvpropr -k , bridging between the relativistic and Newtonian phases (which are described by the Blandford-McKee and Sedov-Taylor self-similar solutions, respectively), as well as to a two-dimensional (2D) cylindrically symmetric impulsive jet propagating in a constant density medium. It is shown that the deceleration to nonrelativistic speeds in one dimension occurs on scales significantly larger than the Sedov length. This transition is further delayed with respect to the Sedov length as the degree of stratification of the ambient medium is increased. This result, together with the scaling of position, Lorentz factor, and the shock velocity as a function of time and shock radius, is explained here using a simple analytical model based on energy conservation. The method used for calculating the afterglow radiation by post-processing the results of the simulations is described in detail. The light curves computed using the results of 1D numerical simulations during the relativistic stage correctly reproduce those calculated assuming the self-similar Blandford-McKee solution for the evolution of the flow. The jet dynamics from our 2D simulations and the resulting afterglow light curves, including the jet break, are in good agreement with those presented in previous works. Finally, we show how the details of the dynamics critically depend on properly resolving the structure of the relativistic flow.
OpenAIRE
2011-01-01
On the basis of the analysis of systems of adaptive management board business proposed the original version of the real system of adaptive management, the basis of which used dynamic recursive model cash flow forecast and real data. Proposed definitions and the simulation of scales and intervals of model time in the control system, as well as the thresholds observations and conditions of changing (correction) of the administrative decisions. The process of adaptive management is illustrated o...
12. Polar firn layering in radiative transfer models
Science.gov (United States)
Linow, Stefanie; Hoerhold, Maria
2016-04-01
For many applications in the geosciences, remote sensing is the only feasible method of obtaining data from large areas with limited accessibility. This is especially true for the cryosphere, where light conditions and cloud coverage additionally limit the use of optical sensors. Here, instruments operating at microwave frequencies become important, for instance in polar snow parameters / SWE (snow water equivalent) mapping. However, the interaction between snow and microwave radiation is a complex process and still not fully understood. RT (radiative transfer) models to simulate snow-microwave interaction are available, but they require a number of input parameters such as microstructure and density, which are partly ill-constrained. The layering of snow and firn introduces an additional degree of complexity, as all snow parameters show a strong variability with depth. Many studies on RT modeling of polar firn deal with layer variability by using statistical properties derived from previous measurements, such as the standard deviations of density and microstructure, to configure model input. Here, the variability of microstructure parameters, such as density and particle size, are usually assumed to be independent of each other. However, in the case of the firn pack of the polar ice sheets, we observe that microstructure evolution depends on environmental parameters, such as temperature and snow deposition. Accordingly, density and microstructure evolve together within the snow and firn. Based on CT (computer tomography) microstructure measurements of antarctic firn, we can show that: first, the variability of density and effective grain size are linked and can thus be implemented in the RT models as a coupled set of parameters. Second, the magnitude of layering is captured by the measured standard deviation. Based on high-resolution density measurements of an Antarctic firn core, we study the effect of firn layering at different microwave wavelengths. By means of
13. Aerosol model selection and uncertainty modelling by adaptive MCMC technique
Directory of Open Access Journals (Sweden)
M. Laine
2008-12-01
Full Text Available We present a new technique for model selection problem in atmospheric remote sensing. The technique is based on Monte Carlo sampling and it allows model selection, calculation of model posterior probabilities and model averaging in Bayesian way.
The algorithm developed here is called Adaptive Automatic Reversible Jump Markov chain Monte Carlo method (AARJ. It uses Markov chain Monte Carlo (MCMC technique and its extension called Reversible Jump MCMC. Both of these techniques have been used extensively in statistical parameter estimation problems in wide area of applications since late 1990's. The novel feature in our algorithm is the fact that it is fully automatic and easy to use.
We show how the AARJ algorithm can be implemented and used for model selection and averaging, and to directly incorporate the model uncertainty. We demonstrate the technique by applying it to the statistical inversion problem of gas profile retrieval of GOMOS instrument on board the ENVISAT satellite. Four simple models are used simultaneously to describe the dependence of the aerosol cross-sections on wavelength. During the AARJ estimation all the models are used and we obtain a probability distribution characterizing how probable each model is. By using model averaging, the uncertainty related to selecting the aerosol model can be taken into account in assessing the uncertainty of the estimates.
Energy Technology Data Exchange (ETDEWEB)
Dux, R.; Kallenbach, A.; Bessenrodt-Weberpals, M.; Behringer, K.; Bosch, H.S.; Fuchs, J.C.; Gehre, O.; Mast, F.; Poschenrieder, W.; Murmann, H.; Salzmann, H.; Schweinzer, J.; Suttrop, W. [MPI fuer Plasmaphysik, EURATOM Association, Garching and Berlin (Germany); ASDEX Upgrade- and NI-Team
1996-02-01
The radiation and transport characteristics of ASDEX Upgrade discharges with a neon driven radiative mantle are modelled using a 1-D radial impurity transport code that has been coupled to a simple divertor model describing particle recycling and pumping. The code is well suited to describe the measured impurity line radiation, total, soft X-ray and bremsstrahlung radiation in regions of the plasma which are not dominated by two dimensional effects. The recycling and pumping behaviour of neon as well as the bulk transport of neon for radiative boundary scenarios are discussed. (orig.)
15. Adaptable Authentication Model: Exploring Security with Weaker Attacker Models
DEFF Research Database (Denmark)
Ahmed, Naveed; Jensen, Christian D.
2011-01-01
suffer because of the identified vulnerabilities. Therefore, we may need to analyze a protocol for weaker notions of security. In this paper, we present a security model that supports such weaker notions. In this model, the overall goals of an authentication protocol are broken into a finer granularity......; for each fine level authentication goal, we determine the “least strongest-attacker” for which the authentication goal can be satisfied. We demonstrate that this model can be used to reason about the security of supposedly insecure protocols. Such adaptability is particularly useful in those applications......Most methods for protocol analysis classify protocols as “broken” if they are vulnerable to attacks from a strong attacker, e.g., assuming the Dolev-Yao attacker model. In many cases, however, exploitation of existing vulnerabilities may not be practical and, moreover, not all applications may...
16. LIMIT THEOREMS AND OPTIMAL DESIGN WITH ADAPTIVE URN MODELS
Institute of Scientific and Technical Information of China (English)
CHEN Guijing; ZHU Chunhua; WANG Yao-hung
2005-01-01
In this paper we study urn model, using some available estimates of successes probabilities, and adding particle parameter, we establish adaptive models. We obtain some strong convergence theorems, rates of convergence, asymptotic normality of components in the urn, and estimates. With these asymptotical results, we show that the adaptive designs given in this paper are asymptotically optimal designs.
17. Adaptive radiation with regard to nutrient sequestration strategies in the carnivorous plants of the genus Nepenthes.
Science.gov (United States)
Pavlovič, Andrej
2012-02-01
Carnivorous pitcher plants of the genus Nepenthes have evolved a great diversity of pitcher morphologies. Selective pressures for maximizing nutrient uptake have driven speciation and diversification of the genus in a process known as adaptive radiation. This leads to the evolution of pitchers adapted to specific and often bizarre source of nutrients, which are not strictly animal-derived. One example is Nepenthes ampullaria with unusual growth pattern and pitcher morphology what enables the plant to capture a leaf litter from the canopy above. We showed that the plant benefits from nitrogen uptake by increased rate of photosynthesis and growth what may provide competitive advantage over others co-habiting plants. A possible impact of such specialization toward hybridization, an important mechanism in speciation, is discussed.
18. Psychophysiological adaptation of the patient with the remote effect of the III degree acute radiation syndrome
Directory of Open Access Journals (Sweden)
Metlyaeva N.A.
2013-12-01
putation of both shins at level in top / 3, late beam buttock, right hip ulcers, a beam cataract of the III degree of both eyes, stabilized. The assessment of the efficiency of psychophysiological adaptation in dynamics with 2009 indicates emergence of prevalence of hypochondriac tendencies over a demonstration with accession of high uneasiness and autistic lines at preservation of the leading role of an hypochondriac somatization of alarm with considerable decrease in an emotionality, an integration, a freedom of behavior. The changes revealed in dynamics correspond to the specific increase weight of violations of mental adaptation, characteristic for the period of adaptation exhaustion. The high intelligence, good figurative and logical thinking, well-mannered forms of behavior, high control over the emotional sphere, restraint of emotions, independence, self-sufficiency, organization, behavior taking into account environment requirements provided the patient M. firmness before a heavy illness, promoted good adaptation to an environment with confidence in myself, high social adaptability, opportunity successfully to carry out duties, hold the work account (worked 39 years after accident. Comparative assessment of operator ability of the patient M. showed good average time of common and difficult sensorimotor reactions with 2 mistakes, high time of reaction for moving object, however decrease in accuracy of reaction from 10-13% to 2% testifies to manifestation in dynamics of insufficiency of real functional reserves of nervous system. Conclusions. Efficiency of psychophysiological adaptation depends not only on a dose of radiation and weight of the transferred disease, but, mostly, on premorbid properties of the identity of the victim and his social and labor installation.
19. A Clinical Concept for Interfractional Adaptive Radiation Therapy in the Treatment of Head and Neck Cancer
Energy Technology Data Exchange (ETDEWEB)
Jensen, Alexandra D., E-mail: [email protected] [Department of Radiation Oncology, University of Heidelberg, Heidelberg (Germany); Nill, Simeon [Department of Medical Physics, German Cancer Research Centre (DKFZ), Heidelberg (Germany); Huber, Peter E. [Clinical Co-Operation Unit Radiation Oncology, German Cancer Research Centre (DKFZ), Heidelberg (Germany); Bendl, Rolf [Department of Medical Physics, German Cancer Research Centre (DKFZ), Heidelberg (Germany); Debus, Juergen; Muenter, Marc W. [Department of Radiation Oncology, University of Heidelberg, Heidelberg (Germany)
2012-02-01
20. Conservatism and adaptability during squirrel radiation: what is mandible shape telling us?
Directory of Open Access Journals (Sweden)
Isaac Casanovas-Vilar
Full Text Available Both functional adaptation and phylogeny shape the morphology of taxa within clades. Herein we explore these two factors in an integrated way by analyzing shape and size variation in the mandible of extant squirrels using landmark-based geometric morphometrics in combination with a comparative phylogenetic analysis. Dietary specialization and locomotion were found to be reliable predictors of mandible shape, with the prediction by locomotion probably reflecting the underlying diet. In addition a weak but significant allometric effect could be demonstrated. Our results found a strong phylogenetic signal in the family as a whole as well as in the main clades, which is in agreement with the general notion of squirrels being a conservative group. This fact does not preclude functional explanations for mandible shape, but rather indicates that ancient adaptations kept a prominent role, with most genera having diverged little from their ancestral clade morphologies. Nevertheless, certain groups have evolved conspicuous adaptations that allow them to specialize on unique dietary resources. Such adaptations mostly occurred in the Callosciurinae and probably reflect their radiation into the numerous ecological niches of the tropical and subtropical forests of Southeastern Asia. Our dietary reconstruction for the oldest known fossil squirrels (Eocene, 36 million years ago show a specialization on nuts and seeds, implying that the development from protrogomorphous to sciuromorphous skulls was not necessarily related to a change in diet.
1. Adaptive response and split-dose effect of radiation on the survival of mice
Ashu Bhan Tiku; R K Kale
2004-03-01
Although the importance of radiation-induced adaptive response has been recognized in human health, risk assessment and clinical application, the phenomenon has not been understood well in terms of survival of animals. To examine this aspect Swiss albino mice were irradiated with different doses (2–10 Gy) at 0.015 Gy/s dose rate and observed on a regular basis for 30 days. Since almost 50% lethality was seen with 8 Gy, it was selected as the challenging dose for further studies. Irradiation of mice with conditioning doses (0.25 or 0.5 Gy) and subsequent exposure to 8 Gy caused significant increase in the survival of mice compared to irradiated control. The splitting of challenging dose did not influence the efficiency of conditioning doses (0.25 Gy and 0.5 Gy) to induce an adaptive response. However conditioning doses given in fractions (0.25 Gy + 0.25 Gy) or (0.5 Gy + 0.5 Gy) were able to modulate the response of challenging dose of 8 Gy. These results clearly showed the occurrence of adaptive response in terms of survival of animals. The conditioning dose given in small fractions seemed to be more effective. The findings have been discussed from a mechanistic point of view. The possible biological implications, potential medical benefits, uncertainties and controversies related to adaptive response have also been addressed.
2. Realistic model for radiation-matter interaction
CERN Document Server
Pakula, R A
2004-01-01
This paper presents a realistic model that describes radiation-matter interactions. This is achieved by a generalization of first quantization, where the Maxwell equations are interpreted as the electromagnetic component of the Schrodinger equation. This picture is complemented by the consideration of electrons and photons as real particles in three-dimensional space, following guiding conditions derived from the particle-wave-functions to which they are associated. The guiding condition for the electron is taken from Bohmian mechanics, while the photon velocity is defined as the ratio between the Poynting vector and the electromagnetic energy density. The case of many particles is considered, taking into account their statistical properties. The formalism is applied to a two level system, providing an intuitive description for spontaneous emission, Lamb shift, scattering, absorption, dispersion, resonance fluorescence and vacuum fields. This model describes quantum jumps by the entanglement between the photo...
3. Radiative Effects in the Standard Model Extension
CERN Document Server
Zhukovskii, V C; Murchikova, E M
2006-01-01
The possibility of radiative effects induced by the Lorentz and CPT non-invariant interaction term for fermions in the Standard Model Extension is investigated. In particular, electron-positron photo-production and photon emission by electrons and positrons were studied. The rates of these processes were calculated in the Furry picture. It was demonstrated that the rates obtained in the framework of the model adopted strongly depend on the polarization states of the particles involved. Indeed, ultra-relativistic particles should occupy states with a preferred spin orientation, i.e., photons have the sign of polarization opposite to the sign of the effective potential, while charged particle are preferably in the state with the helicity coinciding with the sign of the effective potential. This leads to evident spatial asymmetries which may have certain consequences observable in astrophysical and cosmological studies.
4. ADAPTIVE MODEL REFINEMENT FOR THE IONOSPHERE AND THERMOSPHERE
Data.gov (United States)
National Aeronautics and Space Administration — ADAPTIVE MODEL REFINEMENT FOR THE IONOSPHERE AND THERMOSPHERE ANTHONY M. D’AMATO∗, AARON J. RIDLEY∗∗, AND DENNIS S. BERNSTEIN∗∗∗ Abstract. Mathematical models of...
Science.gov (United States)
La Cava, William G.; Danai, Kourosh
2016-01-01
A gradient-based method of symbolic adaptation is introduced for a class of continuous dynamic models. The proposed model structure adaptation method starts with the first-principles model of the system and adapts its structure after adjusting its individual components in symbolic form. A key contribution of this work is its introduction of the model's parameter sensitivity as the measure of symbolic changes to the model. This measure, which is essential to defining the structural sensitivity of the model, not only accommodates algebraic evaluation of candidate models in lieu of more computationally expensive simulation-based evaluation, but also makes possible the implementation of gradient-based optimisation in symbolic adaptation. The proposed method is applied to models of several virtual and real-world systems that demonstrate its potential utility.
6. How Magnetotactic Bacteria Respond to Radiation Induced Stress and Damage: Comparative Genomics Evidences for Evolutionary Adaptation
Science.gov (United States)
Wang, Y.; Pan, Y.
2015-12-01
A mediated umuCD genes and double copied ssb gene, these low fidelity DNA polymerase along with Ssb protein may endow MTB high adaptive mutation under stress condition; 4) also, magnetosome crystals (magnetite or greigite) can reduce radiation oxidative damage and protect MTB.
7. A fast tree-based method for estimating column densities in Adaptive Mesh Refinement codes Influence of UV radiation field on the structure of molecular clouds
CERN Document Server
Valdivia, Valeska
2014-01-01
Context. Ultraviolet radiation plays a crucial role in molecular clouds. Radiation and matter are tightly coupled and their interplay influences the physical and chemical properties of gas. In particular, modeling the radiation propagation requires calculating column densities, which can be numerically expensive in high-resolution multidimensional simulations. Aims. Developing fast methods for estimating column densities is mandatory if we are interested in the dynamical influence of the radiative transfer. In particular, we focus on the effect of the UV screening on the dynamics and on the statistical properties of molecular clouds. Methods. We have developed a tree-based method for a fast estimate of column densities, implemented in the adaptive mesh refinement code RAMSES. We performed numerical simulations using this method in order to analyze the influence of the screening on the clump formation. Results. We find that the accuracy for the extinction of the tree-based method is better than 10%, while the ...
8. Radiation Belt Electron Dynamics: Modeling Atmospheric Losses
Science.gov (United States)
Selesnick, R. S.
2003-01-01
The first year of work on this project has been completed. This report provides a summary of the progress made and the plan for the coming year. Also included with this report is a preprint of an article that was accepted for publication in Journal of Geophysical Research and describes in detail most of the results from the first year of effort. The goal for the first year was to develop a radiation belt electron model for fitting to data from the SAMPEX and Polar satellites that would provide an empirical description of the electron losses into the upper atmosphere. This was largely accomplished according to the original plan (with one exception being that, for reasons described below, the inclusion of the loss cone electrons in the model was deferred). The main concerns at the start were to accurately represent the balance between pitch angle diffusion and eastward drift that determines the dominant features of the low altitude data, and then to accurately convert the model into simulated data based on the characteristics of the particular electron detectors. Considerable effort was devoted to achieving these ends. Once the model was providing accurate results it was applied to data sets selected from appropriate periods in 1997, 1998, and 1999. For each interval of -30 to 60 days, the model parameters were calculated daily, thus providing good short and long term temporal resolution, and for a range of radial locations from L = 2.7 to 3.9. .
9. Ultraviolet radiation therapy and UVR dose models
Energy Technology Data Exchange (ETDEWEB)
Grimes, David Robert, E-mail: [email protected] [School of Physical Sciences, Dublin City University, Glasnevin, Dublin 9, Ireland and Cancer Research UK/MRC Oxford Institute for Radiation Oncology, Gray Laboratory, University of Oxford, Old Road Campus Research Building, Oxford OX3 7DQ (United Kingdom)
2015-01-15
Ultraviolet radiation (UVR) has been an effective treatment for a number of chronic skin disorders, and its ability to alleviate these conditions has been well documented. Although nonionizing, exposure to ultraviolet (UV) radiation is still damaging to deoxyribonucleic acid integrity, and has a number of unpleasant side effects ranging from erythema (sunburn) to carcinogenesis. As the conditions treated with this therapy tend to be chronic, exposures are repeated and can be high, increasing the lifetime probability of an adverse event or mutagenic effect. Despite the potential detrimental effects, quantitative ultraviolet dosimetry for phototherapy is an underdeveloped area and better dosimetry would allow clinicians to maximize biological effect whilst minimizing the repercussions of overexposure. This review gives a history and insight into the current state of UVR phototherapy, including an overview of biological effects of UVR, a discussion of UVR production, illness treated by this modality, cabin design and the clinical implementation of phototherapy, as well as clinical dose estimation techniques. Several dose models for ultraviolet phototherapy are also examined, and the need for an accurate computational dose estimation method in ultraviolet phototherapy is discussed.
10. How plasticity, genetic assimilation and cryptic genetic variation may contribute to adaptive radiations.
Science.gov (United States)
Schneider, Ralf F; Meyer, Axel
2017-01-01
There is increasing evidence that phenotypic plasticity can promote population divergence by facilitating phenotypic diversification and, eventually, genetic divergence. When a 'plastic' population colonizes a new habitat, it has the possibility to occupy multiple niches by expressing several distinct phenotypes. These initially reflect the population's plastic range but may later become genetically fixed by selection via the process of 'genetic assimilation' (GA). Through this process multiple specialized sister lineages can arise that share a common plastic ancestor - the 'flexible stem'. Here, we review possible molecular mechanisms through which natural selection could fix an initially plastic trait during GA. These mechanisms could also explain how GA may contribute to cryptic genetic variation that can subsequently be coopted into other phenotypes or traits, but also lead to nonadaptive responses. We outline the predicted patterns of genetic and transcriptional divergence accompanying flexible stem radiations. The analysis of such patterns of (retained) adaptive and nonadaptive plastic responses within and across radiating lineages can inform on the state of ongoing GA. We conclude that, depending on the stability of the environment, the molecular architecture underlying plastic traits can facilitate diversification, followed by fixation and consolidation of an adaptive phenotype and degeneration of nonadaptive ones. Additionally, the process of GA may increase the cryptic genetic variation of populations, which on one hand may serve as substrate for evolution, but on another may be responsible for nonadaptive responses that consolidate local allopatry and thus reproductive isolation.
CERN Document Server
Men, Chunhua; Jiang, Steve B
2010-01-01
Online adaptive radiation therapy (ART) has great promise to significantly reduce normal tissue toxicity and/or improve tumor control through real-time treatment adaptations based on the current patient anatomy. However, the major technical obstacle for clinical realization of online ART, namely the inability to achieve real-time efficiency in treatment re-planning, has yet to be solved. To overcome this challenge, this paper presents our work on the implementation of an intensity modulated radiation therapy (IMRT) direct aperture optimization (DAO) algorithm on graphics processing unit (GPU) based on our previous work on CPU. We formulate the DAO problem as a large-scale convex programming problem, and use an exact method called column generation approach to deal with its extremely large dimensionality on GPU. Five 9-field prostate and five 5-field head-and-neck IMRT clinical cases with 5\\times5 mm2 beamlet size and 2.5\\times2.5\\times2.5 mm3 voxel size were used to evaluate our algorithm on GPU. It takes onl...
12. Statistical Modeling for Radiation Hardness Assurance: Toward Bigger Data
Science.gov (United States)
2015-01-01
New approaches to statistical modeling in radiation hardness assurance are discussed. These approaches yield quantitative bounds on flight-part radiation performance even in the absence of conventional data sources. This allows the analyst to bound radiation risk at all stages and for all decisions in the RHA process. It also allows optimization of RHA procedures for the project's risk tolerance.
13. A mathematical model for radiation hydrodynamics
Directory of Open Access Journals (Sweden)
Sebastiano Pennisi
1990-11-01
Full Text Available We adopt here the idea of describing a radiation field by means of the radiation energy density E and the radiative flux vector F which must satisfy a set of evolution equations; in these equations an unknown tensorial function P(E,F appears that is determined by the methods of extended thermodynamics.
14. Geant4 models for space radiation environment.
Science.gov (United States)
Ivantchenko, Anton; Nieminen, Petteri; Incerti, Sebastien; Santin, Giovanni; Ivantchenko, Vladimir; Grichine, Vladimir; Allison, John
The space radiation environment includes wide varieties of particles from electrons to heavy ions. In order to correctly predict the dose received by astronauts and devices the simulation models must have good applicability and produce accurate results from 10 MeV/u up to 10 GeV/u, where the most radioactive hazardous particles are present in the spectra. Appropriate models should also provide a good description of electromagnetic interactions down to very low energies (10 eV/u - 10 MeV/u) for understanding the damage mechanisms due to long-term low doses. Predictions of biological dose during long interplanetary journeys also need models for hadronic interactions of energetic heavy ions extending higher energies (10 GeV/u - 100 GeV/u, but possibly up to 1 TeV/u). Geant4 is a powerful toolkit, which in some areas well surpasses the needs from space radiation studies, while in other areas is being developed and/or validated to properly cover the modelling requirements outlined above. Our activities in ESA projects deal with the research and development of both Geant4 hadronic and electromagnetic physics. Recently the scope of verification tests and benchmarks has been extended. Hadronic tests and benchmarks run proton, pion, and ion interactions with matter at various energies. In the Geant4 hadronic sub-libraries, the most accurate cross sections have been identified and selected as a default for all particle types relevant to space applications. Significant developments were carried out for ion/ion interaction models. These now allow one to perform Geant4 simulations for all particle types and energies relevant to space applications. For the validation of ion models the hadronic testing suite for ion interactions was significantly extended. In this work the results of benchmarking versus data in a wide energy range for projectile protons and ions will be shown and discussed. Here we show results of the tests runs and their precision. Recommendations for Geant4
15. Flavour Dependent Gauged Radiative Neutrino Mass Model
CERN Document Server
Baek, Seungwon; Yagyu, Kei
2015-01-01
We propose a one-loop induced radiative neutrino mass model with anomaly free flavour dependent gauge symmetry: $\\mu$ minus $\\tau$ symmetry $U(1)_{\\mu-\\tau}$. A neutrino mass matrix satisfying current experimental data can be obtained by introducing a weak isospin singlet scalar boson that breaks $U(1)_{\\mu-\\tau}$ symmetry, an inert doublet scalar field, and three right-handed neutrinos in addition to the fields in the standard model. We find that a characteristic structure appears in the neutrino mass matrix: two-zero texture form which predicts three non-zero neutrino masses and three non-zero CP-phases which can be determined five well measured experimental inputs of two squared mass differences and three mixing angles. Furthermore, it is clarified that only the inverted mass hierarchy is allowed in our model. In a favored parameter set from the neutrino sector, the discrepancy in the muon anomalous magnetic moment between the experimental data and the the standard model prediction can be explained by the ...
16. Multigene phylogeny of the Mustelidae: Resolving relationships, tempo and biogeographic history of a mammalian adaptive radiation
Directory of Open Access Journals (Sweden)
Veron Geraldine
2008-02-01
17. Histogram Equalization to Model Adaptation for Robust Speech Recognition
Directory of Open Access Journals (Sweden)
Hoirin Kim
2010-01-01
Full Text Available We propose a new model adaptation method based on the histogram equalization technique for providing robustness in noisy environments. The trained acoustic mean models of a speech recognizer are adapted into environmentally matched conditions by using the histogram equalization algorithm on a single utterance basis. For more robust speech recognition in the heavily noisy conditions, trained acoustic covariance models are efficiently adapted by the signal-to-noise ratio-dependent linear interpolation between trained covariance models and utterance-level sample covariance models. Speech recognition experiments on both the digit-based Aurora2 task and the large vocabulary-based task showed that the proposed model adaptation approach provides significant performance improvements compared to the baseline speech recognizer trained on the clean speech data.
18. BYSTANDER EFFECTS, GENOMIC INSTABILITY, ADAPTIVE RESPONSE AND CANCER RISK ASSESSMENT FOR RADIATION AND CHEMICAL EXPOSURES
Science.gov (United States)
There is an increased interest in utilizing mechanistic data in support of the cancer risk assessment process for ionizing radiation and environmental chemical exposures. In this regard the use of biologically based dose-response models is particularly advocated. The aim is to pr...
19. Mathematical Models of Human Hematopoiesis Following Acute Radiation Exposure
Science.gov (United States)
2014-05-01
the model predicts. Radiation dose from skin contamination can result in cutaneous injury leading to systemic responses and may im- pact the observed...medical and performance consequences from radiation and combined injuries , thereby enhancing our understanding of the potential impact of a nuclear...subsequently. In addition to the insight gained from combined injury modeling, the models of hematopoiesis and radiation alone provide clini- cally
20. Rates of morphological evolution in Captorhinidae: an adaptive radiation of Permian herbivores.
Science.gov (United States)
Brocklehurst, Neil
2017-01-01
The evolution of herbivory in early tetrapods was crucial in the establishment of terrestrial ecosystems, although it is so far unclear what effect this innovation had on the macro-evolutionary patterns observed within this clade. The clades that entered this under-filled region of ecospace might be expected to have experienced an "adaptive radiation": an increase in rates of morphological evolution and speciation driven by the evolution of a key innovation. However such inferences are often circumstantial, being based on the coincidence of a rate shift with the origin of an evolutionary novelty. The conclusion of an adaptive radiation may be made more robust by examining the pattern of the evolutionary shift; if the evolutionary innovation coincides not only with a shift in rates of morphological evolution, but specifically in the morphological characteristics relevant to the ecological shift of interest, then one may more plausibly infer a causal relationship between the two. Here I examine the impact of diet evolution on rates of morphological change in one of the earliest tetrapod clades to evolve high-fibre herbivory: Captorhinidae. Using a method of calculating heterogeneity in rates of discrete character change across a phylogeny, it is shown that a significant increase in rates of evolution coincides with the transition to herbivory in captorhinids. The herbivorous captorhinids also exhibit greater morphological disparity than their faunivorous relatives, indicating more rapid exploration of new regions of morphospace. As well as an increase in rates of evolution, there is a shift in the regions of the skeleton undergoing the most change; the character changes in the herbivorous lineages are concentrated in the mandible and dentition. The fact that the increase in rates of evolution coincides with increased change in characters relating to food acquisition provides stronger evidence for a causal relationship between the herbivorous diet and the radiation
1. Stochastic modeling of p53-regulated apoptosis upon radiation damage
CERN Document Server
Bhatt, Divesh; Bahar, Ivet
2011-01-01
We develop and study the evolution of a model of radiation induced apoptosis in cells using stochastic simulations, and identified key protein targets for effective mitigation of radiation damage. We identified several key proteins associated with cellular apoptosis using an extensive literature survey. In particular, we focus on the p53 transcription dependent and p53 transcription independent pathways for mitochondrial apoptosis. Our model reproduces known p53 oscillations following radiation damage. The key, experimentally testable hypotheses that we generate are - inhibition of PUMA is an effective strategy for mitigation of radiation damage if the treatment is administered immediately, at later stages following radiation damage, inhibition of tBid is more effective.
2. ADAPTIVE LEARNING OF HIDDEN MARKOV MODELS FOR EMOTIONAL SPEECH
Directory of Open Access Journals (Sweden)
A. V. Tkachenia
2014-01-01
Full Text Available An on-line unsupervised algorithm for estimating the hidden Markov models (HMM parame-ters is presented. The problem of hidden Markov models adaptation to emotional speech is solved. To increase the reliability of estimated HMM parameters, a mechanism of forgetting and updating is proposed. A functional block diagram of the hidden Markov models adaptation algorithm is also provided with obtained results, which improve the efficiency of emotional speech recognition.
3. A model of radiatively induced quark and lepton mass model
Science.gov (United States)
Nomura, Takaaki
2017-07-01
We discuss a radiatively induced quark and lepton mass model in the rst and second generation introducing extra U(1) gauge symmetry, discrete Z 2 symmetry, vector-like fermions and exotic scalar elds. Then we analyze the allowed parameter regions which simultaneously satisfy the constraints of FCNCs for the quark sector and of LFVs including μ - e conversion, observed quark mass and mixing, and the lepton mass and mixing. In addition, the typical value for the (g - 2) μ in our model is presented. We also show extension of the model in which Majorana type neutrino masses are generated at the two loop level.
Science.gov (United States)
Wu, Q Jackie; Thongphiew, Danthai; Wang, Zhiheng; Mathayomchan, Boonyanit; Chankong, Vira; Yoo, Sua; Lee, W Robert; Yin, Fang-Fang
2008-02-01
For intermediate and high risk prostate cancer, both the prostate gland and seminal vesicles are included in the clinical target volume. Internal motion patterns of these two organs vary, presenting a challenge for adaptive treatment. Adaptive techniques such as isocenter repositioning and soft tissue alignment are effective when tumor volumes only exhibit translational shift, while direct re-optimization of the intensity-modulated radiation therapy (IMRT) plan maybe more desirable when extreme deformation or differential positioning changes of the organs occur. Currently, direct re-optimization of the IMRT plan using beamlet (or fluence map) has not been reported. In this study, we report a novel on-line re-optimization technique that can accomplish plan adjustment on-line. Deformable image registration is used to provide position variation information on each voxel along the three dimensions. The original planned dose distribution is used as the 'goal' dose distribution for adaptation and to ensure planning quality. Fluence maps are re-optimized via linear programming, and a plan solution can be achieved within 2 min. The feasibility of this technique is demonstrated with a clinical case with large deformation. Such on-line ART process can be highly valuable with hypo-fractionated prostate IMRT treatment.
Energy Technology Data Exchange (ETDEWEB)
Wu, Q Jackie [Department of Radiation Oncology, Duke University Medical Center Durham, NC (United States); Thongphiew, Danthai [Department of Radiation Oncology, Duke University Medical Center Durham, NC (United States); Wang, Zhiheng [Department of Radiation Oncology, Duke University Medical Center Durham, NC (United States); Mathayomchan, Boonyanit [Department of Electrical Engineering and Computer Science, Case Western Reserve University Cleveland, OH (United States); Chankong, Vira [Department of Electrical Engineering and Computer Science, Case Western Reserve University Cleveland, OH (United States); Yoo, Sua [Department of Radiation Oncology, Duke University Medical Center Durham, NC (United States); Lee, W Robert [Department of Radiation Oncology, Duke University Medical Center Durham, NC (United States); Yin, Fang-Fang [Department of Radiation Oncology, Duke University Medical Center Durham, NC (United States)
2008-02-07
For intermediate and high risk prostate cancer, both the prostate gland and seminal vesicles are included in the clinical target volume. Internal motion patterns of these two organs vary, presenting a challenge for adaptive treatment. Adaptive techniques such as isocenter repositioning and soft tissue alignment are effective when tumor volumes only exhibit translational shift, while direct re-optimization of the intensity-modulated radiation therapy (IMRT) plan maybe more desirable when extreme deformation or differential positioning changes of the organs occur. Currently, direct re-optimization of the IMRT plan using beamlet (or fluence map) has not been reported. In this study, we report a novel on-line re-optimization technique that can accomplish plan adjustment on-line. Deformable image registration is used to provide position variation information on each voxel along the three dimensions. The original planned dose distribution is used as the 'goal' dose distribution for adaptation and to ensure planning quality. Fluence maps are re-optimized via linear programming, and a plan solution can be achieved within 2 min. The feasibility of this technique is demonstrated with a clinical case with large deformation. Such on-line ART process can be highly valuable with hypo-fractionated prostate IMRT treatment.
Science.gov (United States)
Wu, Q. Jackie; Thongphiew, Danthai; Wang, Zhiheng; Mathayomchan, Boonyanit; Chankong, Vira; Yoo, Sua; Lee, W. Robert; Yin, Fang-Fang
2008-02-01
For intermediate and high risk prostate cancer, both the prostate gland and seminal vesicles are included in the clinical target volume. Internal motion patterns of these two organs vary, presenting a challenge for adaptive treatment. Adaptive techniques such as isocenter repositioning and soft tissue alignment are effective when tumor volumes only exhibit translational shift, while direct re-optimization of the intensity-modulated radiation therapy (IMRT) plan maybe more desirable when extreme deformation or differential positioning changes of the organs occur. Currently, direct re-optimization of the IMRT plan using beamlet (or fluence map) has not been reported. In this study, we report a novel on-line re-optimization technique that can accomplish plan adjustment on-line. Deformable image registration is used to provide position variation information on each voxel along the three dimensions. The original planned dose distribution is used as the 'goal' dose distribution for adaptation and to ensure planning quality. Fluence maps are re-optimized via linear programming, and a plan solution can be achieved within 2 min. The feasibility of this technique is demonstrated with a clinical case with large deformation. Such on-line ART process can be highly valuable with hypo-fractionated prostate IMRT treatment. Abstract and preliminary data presented at 49th AAPM Annual Meeting, Minneapolis, MN, USA, July 2007.
7. Multiple-Model Adaptive Switching Control for Uncertain Multivariable Systems
NARCIS (Netherlands)
Baldi, Simone; Battistelli, Giorgio; Mari, Daniele; Mosca, Edoardo; Tesi, Pietro
2011-01-01
This paper addresses the problem of controlling an uncertain multi-input multi-output (MIMO) system by means of adaptive switching control schemes. In particular, the paper aims at extending the approach of multiple-model unfalsified adaptive switched control, so far restricted to single-input singl
8. Potential Models for Radiative Rare B Decays
CERN Document Server
2002-01-01
We compute the branching ratios for the radiative rare decays of B into K-Meson states and compare them to the experimentally determined branching ratio for inclusive decay b -> s gamma using non relativistic quark model, and form factor definitions consistent with HQET covariant trace formalism. Such calculations necessarily involve a potential model. In order to test the sensitivity of calculations to potential models we have used three different potentials, namely linear potential, screening confining potential and heavy quark potential as it stands in QCD.We find the branching ratios relative to the inclusive b ->s gamma decay to be (16.07\\pm 5.2)% for B -> K^* (892)gamma and (7.25\\pm 3.2)% for B -> K_2^* (1430)gamma for linear potential. In the case of the screening confining potential these values are (19.75\\pm 5.3)% and (4.74\\pm 1.2)% while those for the heavy quark potential are (11.18\\pm 4.6)% and (5.09\\pm 2.7)% respectively. All these values are consistent with the corresponding present CLEO experim...
9. Design and Modeling of a Variable Heat Rejection Radiator
Science.gov (United States)
Miller, Jennifer R.; Birur, Gajanana C.; Ganapathi, Gani B.; Sunada, Eric T.; Berisford, Daniel F.; Stephan, Ryan
2011-01-01
Variable Heat Rejection Radiator technology needed for future NASA human rated & robotic missions Primary objective is to enable a single loop architecture for human-rated missions (1) Radiators are typically sized for maximum heat load in the warmest continuous environment resulting in a large panel area (2) Large radiator area results in fluid being susceptible to freezing at low load in cold environment and typically results in a two-loop system (3) Dual loop architecture is approximately 18% heavier than single loop architecture (based on Orion thermal control system mass) (4) Single loop architecture requires adaptability to varying environments and heat loads
10. Multiple recent co-options of Optix associated with novel traits in adaptive butterfly wing radiations
Science.gov (United States)
2014-01-01
Background While the ecological factors that drive phenotypic radiations are often well understood, less is known about the generative mechanisms that cause the emergence and subsequent diversification of novel features. Heliconius butterflies display an extraordinary diversity of wing patterns due in part to mimicry and sexual selection. Identifying the genetic drivers of this crucible of evolution is now within reach, as it was recently shown that cis-regulatory variation of the optix transcription factor explains red pattern differences in the adaptive radiations of the Heliconius melpomene and Heliconius erato species groups. Results Here, we compare the developmental expression of the Optix protein across a large phylogenetic sample of butterflies and infer that its color patterning role originated at the base of the neotropical passion-vine butterfly clade (Lepidoptera, Nymphalidae, Tribe: Heliconiini), shortly predating multiple Optix-driven wing pattern radiations in the speciose Heliconius and Eueides genera. We also characterize novel Optix and Doublesex expression in the male-specific pheromone wing scales of the basal heliconiines Dryas and Agraulis, thus illustrating that within the Heliconinii lineage, Optix has been evolutionarily redeployed in multiple contexts in association with diverse wing features. Conclusions Our findings reveal that the repeated co-option of Optix into various aspects of wing scale specification was associated with multiple evolutionary novelties over a relatively short evolutionary time scale. In particular, the recruitment of Optix expression in colored scale cell precursors was a necessary condition to the explosive diversification of passion-vine butterfly wing patterns. The novel deployment of a gene followed by spatial modulation of its expression in a given cell type could be a common mode of developmental innovation for triggering phenotypic radiations. PMID:24499528
11. Radiation hydrodynamics with Adaptive Mesh Refinement and application to prestellar core collapse. I Methods
CERN Document Server
Commercon, Benoit; Audit, Edouard; Hennebelle, Patrick; Chabrier, Gilles
2011-01-01
Radiative transfer has a strong impact on the collapse and the fragmentation of prestellar dense cores. We present the radiation-hydrodynamics solver we designed for the RAMSES code. The method is designed for astrophysical purposes, and in particular for protostellar collapse. We present the solver, using the co-moving frame to evaluate the radiative quantities. We use the popular flux limited diffusion approximation, under the grey approximation (one group of photon). The solver is based on the second-order Godunov scheme of RAMSES for its hyperbolic part, and on an implicit scheme for the radiation diffusion and the coupling between radiation and matter. We report in details our methodology to integrate the RHD solver into RAMSES. We test successfully the method against several conventional tests. For validation in 3D, we perform calculations of the collapse of an isolated 1 M_sun prestellar dense core, without rotation. We compare successfully the results with previous studies using different models for r...
12. Predictive Model of Radiative Neutrino Masses
CERN Document Server
Babu, K S
2013-01-01
We present a simple and predictive model of radiative neutrino masses. It is a special case of the Zee model which introduces two Higgs doublets and a charged singlet. We impose a family-dependent Z_4 symmetry acting on the leptons, which reduces the number of parameters describing neutrino oscillations to four. A variety of predictions follow: The hierarchy of neutrino masses must be inverted; the lightest neutrino mass is extremely small and calculable; one of the neutrino mixing angles is determined in terms of the other two; the phase parameters take CP-conserving values with \\delta_{CP} = \\pi; and the effective mass in neutrinoless double beta decay lies in a narrow range, m_{\\beta \\beta} = (17.6 - 18.5) meV. The ratio of vacuum expectation values of the two Higgs doublets, tan\\beta, is determined to be either 1.9 or 0.19 from neutrino oscillation data. Flavor-conserving and flavor-changing couplings of the Higgs doublets are also determined from neutrino data. The non-standard neutral Higgs bosons, if t...
13. Modeling adaptation of carbon use efficiency in microbial communities
Directory of Open Access Journals (Sweden)
Steven D Allison
2014-10-01
14. Adaptive response of blood lymphocytes of inhabitants residing in high background radiation areas of ramsar- micronuclei, apoptosis and comet assays.
Science.gov (United States)
2006-11-01
The hot springs in certain areas of Ramsar contain (226)Ra and (222)Rn. The effects of natural radiation on the inhabitants of these areas and the inhabitant's radiosensitivity or adaptive responses were studied. One group of volunteers from areas with high natural background radiation and another group from areas with normal background radiation were chosen as the case and control group respectively. The frequency of micronuclei, apoptosis, and DNA damage in peripheral blood mononuclear cells were measured following gamma irradiation (4 Gy). The incidence of micronuclei in the case group was significantly lower than that in the control group while their frequency of apoptosis was higher (P sites, the individuals in the case group are more sensitive and susceptible to DNA damage. The results of micronuclei, apoptosis and repair studies suggest that an adaptive response might be induced in people residing in areas with high background radiation.
15. Mutagenic adaptive response to high-LET radiation in human lymphoblastoid cells exposed to X-rays
Energy Technology Data Exchange (ETDEWEB)
Vares, Guillaume, E-mail: [email protected] [National Institute of Radiological Sciences, Anagawa 4-9-1, Inage-ku, Chiba 263-8555 (Japan); Wang, Bing, E-mail: [email protected] [National Institute of Radiological Sciences, Anagawa 4-9-1, Inage-ku, Chiba 263-8555 (Japan); Tanaka, Kaoru; Kakimoto, Ayana; Eguchi-Kasai, Kyomi; Nenoi, Mitsuru [National Institute of Radiological Sciences, Anagawa 4-9-1, Inage-ku, Chiba 263-8555 (Japan)
2011-01-10
16. Mutagenic adaptive response to high-LET radiation in human lymphoblastoid cells exposed to X-rays.
Science.gov (United States)
Varès, Guillaume; Wang, Bing; Tanaka, Kaoru; Kakimoto, Ayana; Eguchi-Kasai, Kyomi; Nenoi, Mitsuru
2011-01-10
17. Computational quantum chemistry and adaptive ligand modeling in mechanistic QSAR.
Science.gov (United States)
De Benedetti, Pier G; Fanelli, Francesca
2010-10-01
Drugs are adaptive molecules. They realize this peculiarity by generating different ensembles of prototropic forms and conformers that depend on the environment. Among the impressive amount of available computational drug discovery technologies, quantitative structure-activity relationship approaches that rely on computational quantum chemistry descriptors are the most appropriate to model adaptive drugs. Indeed, computational quantum chemistry descriptors are able to account for the variation of the intramolecular interactions of the training compounds, which reflect their adaptive intermolecular interaction propensities. This enables the development of causative, interpretive and reasonably predictive quantitative structure-activity relationship models, and, hence, sound chemical information finalized to drug design and discovery.
18. Evaluation of artificial neural network (ANN and adaptive neuro-fuzzy inference system (ANFIS methods in prediction of global solar radiation
Directory of Open Access Journals (Sweden)
AA Sabziparvar
2011-03-01
Full Text Available Solar radiation is an important climate parameter which can affect hydrological and meteorological processes. This parameter is a key element in development of solar energy application studies. The purpose of this study is the assessment of artificial intelligence techniques in prediction of solar radiation (Rs using artificial neural network (ANN and adaptive neuro-fuzzy inference system (ANFIS. Minimum temperature, maximum temperature, average relative humidity, sunshine hours and daily solar radiation recorded in four synoptic stations (Esfahan, Urmieh, Shiraz and Kerman were used during the period 1992-2006. The results showed that ANN and ANFIS intelligent models are powerful tools in prediction of global solar radiation for the selected stations. Prediction by ANN was found to be more accurate than ANFIS. Also, the accuracy of prediction in Kerman with higher sunny hours was better than other stations (R2> 0.9. Additionally, using linear regression model, the most effective factors affecting Rs in each site was introduced. The results revealed that sunshine hour is the most important determining parameter affecting surface solar radiation. In contrast, in most sites minimum air temperature and mean relative humidity showed the least effect on surface global solar radiation.
19. Effective UV radiation from model calculations and measurements
Science.gov (United States)
Feister, Uwe; Grewe, Rolf
1994-01-01
Model calculations have been made to simulate the effect of atmospheric ozone and geographical as well as meteorological parameters on solar UV radiation reaching the ground. Total ozone values as measured by Dobson spectrophotometer and Brewer spectrometer as well as turbidity were used as input to the model calculation. The performance of the model was tested by spectroradiometric measurements of solar global UV radiation at Potsdam. There are small differences that can be explained by the uncertainty of the measurements, by the uncertainty of input data to the model and by the uncertainty of the radiative transfer algorithms of the model itself. Some effects of solar radiation to the biosphere and to air chemistry are discussed. Model calculations and spectroradiometric measurements can be used to study variations of the effective radiation in space in space time. The comparability of action spectra and their uncertainties are also addressed.
20. Molecular phylogeny and evidence for an adaptive radiation of geophagine cichlids from South America (Perciformes: Labroidei).
Science.gov (United States)
López-Fernández, Hernán; Honeycutt, Rodney L; Winemiller, Kirk O
2005-01-01
Nucleotide sequences from the mitochondrial ND4 gene and the nuclear RAG2 gene were used to derive the most extensive molecular phylogeny to date for the Neotropical cichlid subfamily Geophaginae. Previous hypotheses of relationships were tested in light of these new data and a synthesis of all existing molecular information was provided. Novel phylogenetic findings included support for : (1) a 'Big Clade' containing the genera Geophagus sensu lato, Gymnogeophagus, Mikrogeophagus, Biotodoma, Crenicara, and Dicrossus; (2) a clade including the genera Satanoperca, Apistogramma, Apistogrammoides, and Taeniacara; and (3) corroboration for Kullander's clade Acarichthyini. ND4 demonstrated saturation effects at the third code position and lineage-specific rate heterogeneity, both of which influenced phylogeny reconstruction when only equal weighted parsimony was employed. Both branch lengths and internal branch tests revealed extremely short basal nodes that add support to the idea that geophagine cichlids have experienced an adaptive radiation sensu Schluter that involved ecomorphological specializations and life history diversification.
1. Morphological divergence in a continental adaptive radiation: South American ovenbirds of the genus Cinclodes
Science.gov (United States)
Rader, Jonathan A.; Dillon, Michael E.; Chesser, R. Terry; Sabat, Pablo; Martinez del Rio, Carlos
2015-01-01
Cinclodes is an ecologically diverse genus of South American passerine birds and represents a case of continental adaptive radiation along multiple axes. We investigated morphological diversification in Cinclodes using a comprehensive set of morphometric measurements of study skins. Principal component analysis identified 2 primary axes of morphological variation: one describing body size and a second capturing differences in wing-tip shape and toe length. Phylogenetic analyses of the first principal component suggest an early divergence ofCinclodes into 2 main clades characterized by large and small body sizes. We suggest that 2 morphological outliers within these main clades (C. antarcticus and C. palliatus) may be cases of island gigantism and that a third (C. patagonicus) may reflect ecological character displacement. Despite its ecological and physiological diversity, the genus Cinclodes does not appear to show morphological diversity beyond what is typical of other avian genera.
2. Removal of noises from electromagnetic radiation of coal or rock with EEMD-adaptive morphological filter
Institute of Scientific and Technical Information of China (English)
CHEN Shi-hai; WANG En-yuan
2012-01-01
The electromagnetic radiation (EMR) signal collected by monitoring system during coal or rock dynamic disaster may be interferred easily by electromagnetic noises in mines.The noises have a direct influence on the recognition and analysis of the EMR signal features during the disaster.With the aim of removing these noises,an ensemble empirical mode decomposition (EEMD) adaptive morphological filter was proposed.From the result of the simulation and the experiment,it is shown that the method can restrain the random noise and white Gaussian noise mixed with EMR signal effectively.The filter is highly useful for improving the robustness of the coal or rock dynamic disaster monitoring system.
3. An adaptation model for trabecular bone at different mechanical levels
Directory of Open Access Journals (Sweden)
Lv Linwei
2010-07-01
Science.gov (United States)
Alexandrou, Aris T.
2014-01-01
Abstract Significance: There are accruing concerns on potential genotoxic agents present in the environment including low-dose ionizing radiation (LDIR) that naturally exists on earth's surface and atmosphere and is frequently used in medical diagnosis and nuclear industry. Although its long-term health risk is being evaluated and remains controversial, LDIR is shown to induce temporary but significant adaptive responses in mammalian cells and animals. The mechanisms guiding the mitochondrial function in LDIR-induced adaptive response represent a unique communication between DNA damage and cellular metabolism. Elucidation of the LDIR-regulated mitochondrial activity may reveal new mechanisms adjusting cellular function to cope with hazardous environmental stress. Recent Advances: Key cell cycle regulators, including Cyclin D1/CDK4 and Cyclin B1/cyclin-dependent kinase 1 (CDK1) complexes, are actively involved in the regulation of mitochondrial functions via phosphorylation of their mitochondrial targets. Accumulating new evidence supports a concept that the Cyclin B1/CDK1 complex acts as a mediator in the cross talk between radiation-induced DNA damage and mitochondrial functions to coordinate cellular responses to low-level genotoxic stresses. Critical Issues: The LDIR-mediated mitochondrial activity via Cyclin B1/CDK1 regulation is an irreplaceable network that is able to harmonize vital cellular functions with adjusted mitochondrial metabolism to enhance cellular homeostasis. Future Directions: Further investigation of the coordinative mechanism that regulates mitochondrial activities in sublethal stress conditions, including LDIR, will reveal new insights of how cells cope with genotoxic injury and will be vital for future targeted therapeutic interventions that reduce environmental injury and cancer risk. Antioxid. Redox Signal. 20, 1463–1480. PMID:24180340
Science.gov (United States)
Alexandrou, Aris T; Li, Jian Jian
2014-03-20
There are accruing concerns on potential genotoxic agents present in the environment including low-dose ionizing radiation (LDIR) that naturally exists on earth's surface and atmosphere and is frequently used in medical diagnosis and nuclear industry. Although its long-term health risk is being evaluated and remains controversial, LDIR is shown to induce temporary but significant adaptive responses in mammalian cells and animals. The mechanisms guiding the mitochondrial function in LDIR-induced adaptive response represent a unique communication between DNA damage and cellular metabolism. Elucidation of the LDIR-regulated mitochondrial activity may reveal new mechanisms adjusting cellular function to cope with hazardous environmental stress. Key cell cycle regulators, including Cyclin D1/CDK4 and Cyclin B1/cyclin-dependent kinase 1 (CDK1) complexes, are actively involved in the regulation of mitochondrial functions via phosphorylation of their mitochondrial targets. Accumulating new evidence supports a concept that the Cyclin B1/CDK1 complex acts as a mediator in the cross talk between radiation-induced DNA damage and mitochondrial functions to coordinate cellular responses to low-level genotoxic stresses. The LDIR-mediated mitochondrial activity via Cyclin B1/CDK1 regulation is an irreplaceable network that is able to harmonize vital cellular functions with adjusted mitochondrial metabolism to enhance cellular homeostasis. Further investigation of the coordinative mechanism that regulates mitochondrial activities in sublethal stress conditions, including LDIR, will reveal new insights of how cells cope with genotoxic injury and will be vital for future targeted therapeutic interventions that reduce environmental injury and cancer risk.
6. Adapting Dynamic Mathematical Models to a Pilot Anaerobic Digestion Reactor
Directory of Open Access Journals (Sweden)
F. Haugen, R. Bakke, and B. Lie
2013-04-01
Full Text Available A dynamic model has been adapted to a pilot anaerobic reactor fed diarymanure. Both steady-state data from online sensors and laboratory analysis anddynamic operational data from online sensors are used in the model adaptation.The model is based on material balances, and comprises four state variables,namely biodegradable volatile solids, volatile fatty acids, acid generatingmicrobes (acidogens, and methane generating microbes (methanogens. The modelcan predict the methane gas flow produced in the reactor. The model may beused for optimal reactor design and operation, state-estimation and control.Also, a dynamic model for the reactor temperature based on energy balance ofthe liquid in the reactor is adapted. This model may be used for optimizationand control when energy and economy are taken into account.
7. Modeling Students' Memory for Application in Adaptive Educational Systems
Science.gov (United States)
2015-01-01
Human memory has been thoroughly studied and modeled in psychology, but mainly in laboratory setting under simplified conditions. For application in practical adaptive educational systems we need simple and robust models which can cope with aspects like varied prior knowledge or multiple-choice questions. We discuss and evaluate several models of…
8. High and Low Doses of Ionizing Radiation Induce Different Secretome Profiles in a Human Skin Model
Energy Technology Data Exchange (ETDEWEB)
Zhang, Qibin; Matzke, Melissa M.; Schepmoes, Athena A.; Moore, Ronald J.; Webb-Robertson, Bobbie-Jo M.; Hu, Zeping; Monroe, Matthew E.; Qian, Weijun; Smith, Richard D.; Morgan, William F.
2014-03-18
9. Convergence of gut microbiotas in the adaptive radiations of African cichlid fishes.
Science.gov (United States)
Baldo, Laura; Pretus, Joan Lluís; Riera, Joan Lluís; Musilova, Zuzana; Bitja Nyom, Arnold Roger; Salzburger, Walter
2017-09-01
Ecoevolutionary dynamics of the gut microbiota at the macroscale level, that is, in across-species comparisons, are largely driven by ecological variables and host genotype. The repeated explosive radiations of African cichlid fishes in distinct lakes, following a dietary diversification in a context of reduced genetic diversity, provide a natural setup to explore convergence, divergence and repeatability in patterns of microbiota dynamics as a function of the host diet, phylogeny and environment. Here we characterized by 16S rRNA amplicon sequencing the gut microbiota of 29 cichlid species from two distinct lakes/radiations (Tanganyika and Barombi Mbo) and across a broad dietary and phylogenetic range. Within each lake, a significant deviation between a carnivorous and herbivorous lifestyle was found. Herbivore species were characterized by an increased bacterial taxonomic and functional diversity and converged in key compositional and functional community aspects. Despite a significant lake effect on the microbiota structure, this process has occurred with remarkable parallels in the two lakes. A metabolic signature most likely explains this trend, as indicated by a significant enrichment in herbivores/omnivores of bacterial taxa and functions associated with fiber degradation and detoxification of plant chemical compounds. Overall, compositional and functional aspects of the gut microbiota individually and altogether validate and predict main cichlid dietary habits, suggesting a fundamental role of gut bacteria in cichlid niche expansion and adaptation.
10. The Adaptation Fund: a model for the future?
Energy Technology Data Exchange (ETDEWEB)
Chandani, Achala; Harmeling, Sven; Kaloga, Alpha Oumar
2009-08-15
With millions of the poor already facing the impacts of a changing climate, adaptation is a globally urgent – and costly – issue. The Adaptation Fund, created under the Kyoto Protocol, has unique features that could herald a new era of international cooperation on adaptation. Its governance structure, for instance, offers a fresh approach to fund management under the UN climate convention. The Fund's Board has also developed a constructive working atmosphere, and further progress is expected before the 2009 climate summit in Copenhagen. But developing countries' demand for adaptation funding is huge: conservative estimates put it at US50 billion a year. The Fund's current structure and funding base are clearly only a first step towards filling that gap. And despite its significant progress over the last 18 months, many countries, particularly in the developed world, remain sceptical about this approach. Looking in detail at the Fund's evolution offers insight into its future potential as a model for adaptation finance. 11. Parallel ecological diversification in Antarctic notothenioid fishes as evidence for adaptive radiation. Science.gov (United States) Rutschmann, Sereina; Matschiner, Michael; Damerau, Malte; Muschick, Moritz; Lehmann, Moritz F; Hanel, Reinhold; Salzburger, Walter 2011-11-01 Antarctic notothenioid fishes represent a rare example of a marine species flock. They evolved special adaptations to the extreme environment of the Southern Ocean including antifreeze glycoproteins. Although lacking a swim bladder, notothenioids have diversified from their benthic ancestor into a wide array of water column niches, such as epibenthic, semipelagic, cryopelagic and pelagic habitats. Applying stable carbon (C) and nitrogen (N) isotope analyses to gain information on feeding ecology and foraging habitats, we tested whether ecological diversification along the benthic-pelagic axis followed a single directional trend in notothenioids, or whether it evolved independently in several lineages. Population samples of 25 different notothenioid species were collected around the Antarctic Peninsula, the South Orkneys and the South Sandwich Islands. The C and N stable isotope signatures span a broad range (mean δ(13) C and δ(15) N values between -25.4‰ and -21.9‰ and between 8.5‰ and 13.8‰, respectively), and pairwise niche overlap between four notothenioid families was highly significant. Analysis of isotopic disparity-through-time on the basis of Bayesian inference and maximum-likelihood phylogenies, performed on a concatenated mitochondrial (cyt b) and nuclear gene (myh6, Ptr and tbr1) data set (3148 bp), showed that ecological diversification into overlapping feeding niches has occurred multiple times in parallel in different notothenioid families. This convergent diversification in habitat and trophic ecology is a sign of interspecific competition and characteristic for adaptive radiations. 12. Automated registration of large deformations for adaptive radiation therapy of prostate cancer Energy Technology Data Exchange (ETDEWEB) Godley, Andrew; Ahunbay, Ergun; Peng Cheng; Li, X. Allen [Department of Radiation Oncology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, Wisconsin 53226 (United States) 2009-04-15 Available deformable registration methods are often inaccurate over large organ variation encountered, for example, in the rectum and bladder. The authors developed a novel approach to accurately and effectively register large deformations in the prostate region for adaptive radiation therapy. A software tool combining a fast symmetric demons algorithm and the use of masks was developed in C++ based on ITK libraries to register CT images acquired at planning and before treatment fractions. The deformation field determined was subsequently used to deform the delivered dose to match the anatomy of the planning CT. The large deformations involved required that the bladder and rectum volume be masked with uniform intensities of -1000 and 1000 HU, respectively, in both the planning and treatment CTs. The tool was tested for five prostate IGRT patients. The average rectum planning to treatment contour overlap improved from 67% to 93%, the lowest initial overlap is 43%. The average bladder overlap improved from 83% to 98%, with a lowest initial overlap of 60%. Registration regions were set to include a volume receiving 4% of the maximum dose. The average region was 320x210x63, taking approximately 9 min to register on a dual 2.8 GHz Linux system. The prostate and seminal vesicles were correctly placed even though they are not masked. The accumulated doses for multiple fractions with large deformation were computed and verified. The tool developed can effectively supply the previously delivered dose for adaptive planning to correct for interfractional changes. 13. Adaptive Networks Theory, Models and Applications CERN Document Server Gross, Thilo 2009-01-01 With adaptive, complex networks, the evolution of the network topology and the dynamical processes on the network are equally important and often fundamentally entangled. Recent research has shown that such networks can exhibit a plethora of new phenomena which are ultimately required to describe many real-world networks. Some of those phenomena include robust self-organization towards dynamical criticality, formation of complex global topologies based on simple, local rules, and the spontaneous division of "labor" in which an initially homogenous population of network nodes self-organizes into functionally distinct classes. These are just a few. This book is a state-of-the-art survey of those unique networks. In it, leading researchers set out to define the future scope and direction of some of the most advanced developments in the vast field of complex network science and its applications. 14. Radiation treatment for the right naris in a pediatric anesthesia patient using an adaptive oral airway technique Energy Technology Data Exchange (ETDEWEB) Sponseller, Patricia, E-mail: [email protected]; Pelly, Nicole; Trister, Andrew; Ford, Eric; Ermoian, Ralph 2015-10-01 Radiation therapy for pediatric patients often includes the use of intravenous anesthesia with supplemental oxygen delivered via the nasal cannula. Here, we describe the use of an adaptive anesthesia technique for electron irradiation of the right naris in a preschool-aged patient treated under anesthesia. The need for an intranasal bolus plug precluded the use of standard oxygen supplementation. This novel technique required the multidisciplinary expertise of anesthesiologists, radiation therapists, medical dosimetrists, medical physicists, and radiation oncologists to ensure a safe and reproducible treatment course. 15. Research on the Adaptive Object-Model Architecture Style Institute of Scientific and Technical Information of China (English) YAO Hai-qiong; NI Gui-qiang 2004-01-01 The rapidly changing requirements and business rules stimulate software developers to make their applications more dynamic, configurable, and adaptable. An effective way to meet such requirements is to apply an adaptive object-model (AOM). The AOM architecture style is composed of metamodel, model engine and tools. Firstly, two small patterns for building up metamodel are analyzed in detail. Then model engine for interpreting metamodel and tools for end-uses to define and configure object models are discussed. Finally, a novel platform-applicationware-is proposed. 16. Modeling Radiative Heat Transfer and Turbulence-Radiation Interactions in Engines Energy Technology Data Exchange (ETDEWEB) Paul, Chandan [Pennsylvania State Univ., University Park, PA (United States); Sircar, Arpan [Pennsylvania State Univ., University Park, PA (United States); Ferreyro-Fernandez, Sebastian [Pennsylvania State Univ., University Park, PA (United States); Imren, Abdurrahman [Pennsylvania State Univ., University Park, PA (United States); Haworth, Daniel C [Pennsylvania State Univ., University Park, PA (United States); Roy, Somesh P [Marquette University (United States); Ge, Wenjun [University of California Merced (United States); Modest, Michael F [University of California Merced (United States) 2017-04-26 Detailed radiation modelling in piston engines has received relatively little attention to date. Recently, it is being revisited in light of current trends towards higher operating pressures and higher levels of exhaust-gas recirculation, both of which enhance molecular gas radiation. Advanced high-efficiency engines also are expected to function closer to the limits of stable operation, where even small perturbations to the energy balance can have a large influence on system behavior. Here several different spectral radiation property models and radiative transfer equation (RTE) solvers have been implemented in an OpenFOAM-based engine CFD code, and simulations have been performed for a full-load (peak pressure ~200 bar) heavy-duty diesel engine. Differences in computed temperature fields, NO and soot levels, and wall heat transfer rates are shown for different combinations of spectral models and RTE solvers. The relative importance of molecular gas radiation versus soot radiation is examined. And the influence of turbulence-radiation interactions is determined by comparing results obtained using local mean values of composition and temperature to compute radiative emission and absorption with those obtained using a particle-based transported probability density function method. 17. The Distance Field Model and Distance Constrained MAP Adaptation Algorithm Institute of Scientific and Technical Information of China (English) YUPeng; WANGZuoying 2003-01-01 Spatial structure information, i.e., the rel-ative position information of phonetic states in the feature space, is long to be carefully researched yet. In this pa-per, a new model named “Distance Field” is proposed to describe the spatial structure information. Based on this model, a modified MAP adaptation algorithm named dis-tance constrained maximum a poateriori (DCMAP) is in-troduced. The distance field model gives large penalty when the spatial structure is destroyed. As a result the DCMAP reserves the spatial structure information in adaptation process. Experiments show the Distance Field Model improves the performance of MAP adapta-tion. Further results show DCMAP has strong cross-state estimation ability, which is used to train a well-performed speaker-dependent model by data from only part of pho- 18. Comprehensive Evaluation Cloud Model for Ship Navigation Adaptability OpenAIRE Man Zhu; Y.Q. Wen; Zhou, C. H.; C.S. Xiao 2014-01-01 In this paper, using cloud model and Delphi, we build a comprehensive evaluation cloud model to solve the problems of qualitative description and quantitative transformation in ship navigation adaptability comprehensive evaluation. In the model, the normal cloud generator is used to find optimal cloud models of reviews and evaluation factors. The weight of each evaluation factor is determined by cloud model and Delphi. The floating cloud algorithm is applied to aggregate the bottom level’s ev... 19. Modeling classical and quantum radiation from laser-plasma accelerators Directory of Open Access Journals (Sweden) M. Chen 2013-03-01 Full Text Available The development of models and the “Virtual Detector for Synchrotron Radiation” (vdsr code that accurately describe the production of synchrotron radiation are described. These models and code are valid in the classical and linear (single-scattering quantum regimes and are capable of describing radiation produced from laser-plasma accelerators (LPAs through a variety of mechanisms including betatron radiation, undulator radiation, and Thomson/Compton scattering. Previous models of classical synchrotron radiation, such as those typically used for undulator radiation, are inadequate in describing the radiation spectra from electrons undergoing small numbers of oscillations. This is due to an improper treatment of a mathematical evaluation at the end points of an integration that leads to an unphysical plateau in the radiation spectrum at high frequencies, the magnitude of which increases as the number of oscillation periods decreases. This is important for betatron radiation from LPAs, in which the betatron strength parameter is large but the number of betatron periods is small. The code vdsr allows the radiation to be calculated in this regime by full integration over each electron trajectory, including end-point effects, and this code is used to calculate betatron radiation for cases of experimental interest. Radiation from Thomson scattering and Compton scattering is also studied with vdsr. For Thomson scattering, radiation reaction is included by using the Sokolov method for the calculation of the electron dynamics. For Compton scattering, quantum recoil effects are considered in vdsr by using Monte Carlo methods. The quantum calculation has been benchmarked with the classical calculation in a classical regime. 20. Methodologies in the modeling of combined chemo-radiation treatments Science.gov (United States) Grassberger, C.; Paganetti, H. 2016-11-01 The variety of treatment options for cancer patients has increased significantly in recent years. Not only do we combine radiation with surgery and chemotherapy, new therapeutic approaches such as immunotherapy and targeted therapies are starting to play a bigger role. Physics has made significant contributions to radiation therapy treatment planning and delivery. In particular, treatment plan optimization using inverse planning techniques has improved dose conformity considerably. Furthermore, medical physics is often the driving force behind tumor control and normal tissue complication modeling. While treatment optimization and outcome modeling does focus mainly on the effects of radiation, treatment modalities such as chemotherapy are treated independently or are even neglected entirely. This review summarizes the published efforts to model combined modality treatments combining radiation and chemotherapy. These models will play an increasing role in optimizing cancer therapy not only from a radiation and drug dosage standpoint, but also in terms of spatial and temporal optimization of treatment schedules. 1. Model-based design of adaptive embedded systems CERN Document Server Hamberg, Roelof; Reckers, Frans; Verriet, Jacques 2013-01-01 Today’s embedded systems have to operate in a wide variety of dynamically changing environmental circumstances. Adaptivity, the ability of a system to autonomously adapt itself, is a means to optimise a system’s behaviour to accommodate changes in its environment. It involves making in-product trade-offs between system qualities at system level. The main challenge in the development of adaptive systems is keeping control of the intrinsic complexity of such systems while working with multi-disciplinary teams to create different parts of the system. Model-Based Development of Adaptive Embedded Systems focuses on the development of adaptive embedded systems both from an architectural and methodological point of view. It describes architectural solution patterns for adaptive systems and state-of-the-art model-based methods and techniques to support adaptive system development. In particular, the book describes the outcome of the Octopus project, a cooperation of a multi-disciplinary team of academic and indus... 2. Environmental Radiation Effects on Mammals A Dynamical Modeling Approach CERN Document Server Smirnova, Olga A 2010-01-01 This text is devoted to the theoretical studies of radiation effects on mammals. It uses the framework of developed deterministic mathematical models to investigate the effects of both acute and chronic irradiation in a wide range of doses and dose rates on vital body systems including hematopoiesis, small intestine and humoral immunity, as well as on the development of autoimmune diseases. Thus, these models can contribute to the development of the system and quantitative approaches in radiation biology and ecology. This text is also of practical use. Its modeling studies of the dynamics of granulocytopoiesis and thrombocytopoiesis in humans testify to the efficiency of employment of the developed models in the investigation and prediction of radiation effects on these hematopoietic lines. These models, as well as the properly identified models of other vital body systems, could provide a better understanding of the radiation risks to health. The modeling predictions will enable the implementation of more ef... 3. Basic Research on Adaptive Model Algorithmic Control Science.gov (United States) 1985-12-01 Control Conference. Richalet, J., A. Rault, J.L. Testud and J. Papon (1978). Model predictive heuristic control: applications to industrial...pp.977-982. Richalet, J., A. Rault, J. L. Testud and J. Papon (1978). Model predictive heuristic control: applications to industrial processes 4. Development and evaluation of novel forecasting adaptive ensemble model Directory of Open Access Journals (Sweden) C.M. Anish 2016-09-01 Full Text Available This paper proposes a new ensemble based adaptive forecasting structure for efficient different interval days' ahead prediction of five different asset values (NAV. In this approach three individual adaptive structures such as adaptive moving average (AMA, adaptive auto regressive moving average (AARMA and feedback radial basis function network (FRBF are employed to first train with conventional LMS, conventional forward-backward LMS and corresponding learning algorithm of FRBF respectively. After successful validation of each model the output obtained by each individual model is optimally weighted using Genetic algorithm (GA as well as particle swarm optimization (PSO based techniques to produce the best possible different days ahead prediction accuracy. Finally the results of prediction obtained of the NAV values are compared with the results obtained by individual predictors as well as by other four existing ensemble schemes. It is in general demonstrated that in all cases the proposed forecasting scheme outperforms other competitive methods. 5. Improved Gaussian Mixture Models for Adaptive Foreground Segmentation DEFF Research Database (Denmark) Katsarakis, Nikolaos; Pnevmatikakis, Aristodemos; Tan, Zheng-Hua 2016-01-01 Adaptive foreground segmentation is traditionally performed using Stauffer & Grimson’s algorithm that models every pixel of the frame by a mixture of Gaussian distributions with continuously adapted parameters. In this paper we provide an enhancement of the algorithm by adding two important dynamic...... elements to the baseline algorithm: The learning rate can change across space and time, while the Gaussian distributions can be merged together if they become similar due to their adaptation process. We quantify the importance of our enhancements and the effect of parameter tuning using an annotated... 6. Treatment of cloud radiative effects in general circulation models Energy Technology Data Exchange (ETDEWEB) Wang, W.C.; Dudek, M.P.; Liang, X.Z.; Ding, M. [State Univ. of New York, Albany, NY (United States)] [and others 1996-04-01 We participate in the Atmospheric Radiation Measurement (ARM) program with two objectives: (1) to improve the general circulation model (GCM) cloud/radiation treatment with a focus on cloud verticle overlapping and layer cloud optical properties, and (2) to study the effects of cloud/radiation-climate interaction on GCM climate simulations. This report summarizes the project progress since the Fourth ARM Science Team meeting February 28-March 4, 1994, in Charleston, South Carolina. 7. Integration of the Radiation Belt Environment Model Into the Space Weather Modeling Framework Science.gov (United States) Glocer, A.; Toth, G.; Fok, M.; Gombosi, T.; Liemohn, M. 2009-01-01 We have integrated the Fok radiation belt environment (RBE) model into the space weather modeling framework (SWMF). RBE is coupled to the global magnetohydrodynamics component (represented by the Block-Adaptive-Tree Solar-wind Roe-type Upwind Scheme, BATS-R-US, code) and the Ionosphere Electrodynamics component of the SWMF, following initial results using the Weimer empirical model for the ionospheric potential. The radiation belt (RB) model solves the convection-diffusion equation of the plasma in the energy range of 10 keV to a few MeV. In stand-alone mode RBE uses Tsyganenko's empirical models for the magnetic field, and Weimer's empirical model for the ionospheric potential. In the SWMF the BATS-R-US model provides the time dependent magnetic field by efficiently tracing the closed magnetic field-lines and passing the geometrical and field strength information to RBE at a regular cadence. The ionosphere electrodynamics component uses a two-dimensional vertical potential solver to provide new potential maps to the RBE model at regular intervals. We discuss the coupling algorithm and show some preliminary results with the coupled code. We run our newly coupled model for periods of steady solar wind conditions and compare our results to the RB model using an empirical magnetic field and potential model. We also simulate the RB for an active time period and find that there are substantial differences in the RB model results when changing either the magnetic field or the electric field, including the creation of an outer belt enhancement via rapid inward transport on the time scale of tens of minutes. 8. Modeling Power Systems as Complex Adaptive Systems Energy Technology Data Exchange (ETDEWEB) Chassin, David P.; Malard, Joel M.; Posse, Christian; Gangopadhyaya, Asim; Lu, Ning; Katipamula, Srinivas; Mallow, J V. 2004-12-30 Physical analogs have shown considerable promise for understanding the behavior of complex adaptive systems, including macroeconomics, biological systems, social networks, and electric power markets. Many of today's most challenging technical and policy questions can be reduced to a distributed economic control problem. Indeed, economically based control of large-scale systems is founded on the conjecture that the price-based regulation (e.g., auctions, markets) results in an optimal allocation of resources and emergent optimal system control. This report explores the state-of-the-art physical analogs for understanding the behavior of some econophysical systems and deriving stable and robust control strategies for using them. We review and discuss applications of some analytic methods based on a thermodynamic metaphor, according to which the interplay between system entropy and conservation laws gives rise to intuitive and governing global properties of complex systems that cannot be otherwise understood. We apply these methods to the question of how power markets can be expected to behave under a variety of conditions. 9. Multilevel UV-B Attenuance : Morphological and Chemical Adaptations of Vicia faba to Ultraviolet-B Radiation NARCIS (Netherlands) Meijkamp, B.B. 2006-01-01 Due to anthropogenic reduction of stratospheric ozone, levels of potentially harmful solar UV-B radiation (280-315 nm) have been increasing on earth during the last three decades. The main aim of this thesis was to study growth responses and morphological and chemical adaptation mechanisms to harmf 10. Brugga basin's TACD Model Adaptation to current GIS PCRaster 4.1 Science.gov (United States) Lopez Rozo, Nicolas Antonio; Corzo Perez, Gerald Augusto; Santos Granados, Germán Ricardo 2017-04-01 The process-oriented catchment model TACD (Tracer-Aided Catchment model - Distributed) was developed in the Brugga Basin (Dark Forest, Germany) with a modular structure in the Geographic Information System PCRaster Version 2, in order to dynamically model the natural processes of a complex Basin, such as rainfall, air temperature, solar radiation, evapotranspiration and flow routing among others. Further research and application on this model has been done, such as adapting other meso-scaled basins and adding erosion processes in the hydrological model. However, TACD model is computationally intensive. This has made it not efficient on large and well discretized river basins. Aswell, the current version is not compatible with latest PCRaster Version 4.1, which offers new capabilities on 64-bit hardware architecture, hydraulic calculation improvements, in maps creation, some error and bug fixes. The current work studied and adapted TACD model into the latest GIS PCRaster Version 4.1. This was done by editing the original scripts, replacing deprecated functionalities without losing correctness of the TACD model. The correctness of the adapted TACD model was verified by using the original study case of the Brugga Basin and comparing the adapted model results with the original model results by Stefan Roser in 2001. Small differences were found due to the fact that some hydraulic and hydrological routines were optimized since version 2 of GIS PCRaster. Therefore, the hydraulic and hydrological processes are well represented. With this new working model, further research and development on current topics like uncertainty analysis, GCM downscaling techniques and spatio-temporal modelling are encouraged. 11. Adaptive Modeling and Real-Time Simulation Science.gov (United States) 1984-01-01 34 Artificial Inteligence , Vol. 13, pp. 27-39 (1980). Describes circumscription which is just the assumption that everything that is known to have a particular... Artificial Intelligence Truth Maintenance Planning Resolution Modeling Wcrld Models ~ .. ~2.. ASSTR AT (Coninue n evrse sieIf necesaran Identfy by...represents a marriage of (1) the procedural-network st, planning technology developed in artificial intelligence with (2) the PERT/CPM technology developed in 12. Sunspot Modeling: From Simplified Models to Radiative MHD Simulations Directory of Open Access Journals (Sweden) Rolf Schlichenmaier 2011-09-01 Full Text Available We review our current understanding of sunspots from the scales of their fine structure to their large scale (global structure including the processes of their formation and decay. Recently, sunspot models have undergone a dramatic change. In the past, several aspects of sunspot structure have been addressed by static MHD models with parametrized energy transport. Models of sunspot fine structure have been relying heavily on strong assumptions about flow and field geometry (e.g., flux-tubes, "gaps", convective rolls, which were motivated in part by the observed filamentary structure of penumbrae or the necessity of explaining the substantial energy transport required to maintain the penumbral brightness. However, none of these models could self-consistently explain all aspects of penumbral structure (energy transport, filamentation, Evershed flow. In recent years, 3D radiative MHD simulations have been advanced dramatically to the point at which models of complete sunspots with sufficient resolution to capture sunspot fine structure are feasible. Here overturning convection is the central element responsible for energy transport, filamentation leading to fine-structure and the driving of strong outflows. On the larger scale these models are also in the progress of addressing the subsurface structure of sunspots as well as sunspot formation. With this shift in modeling capabilities and the recent advances in high resolution observations, the future research will be guided by comparing observation and theory. 13. Adaptive network models of collective decision making in swarming systems Science.gov (United States) Chen, Li; Huepe, Cristián; Gross, Thilo 2016-08-01 We consider a class of adaptive network models where links can only be created or deleted between nodes in different states. These models provide an approximate description of a set of systems where nodes represent agents moving in physical or abstract space, the state of each node represents the agent's heading direction, and links indicate mutual awareness. We show analytically that the adaptive network description captures a phase transition to collective motion in some swarming systems, such as the Vicsek model, and that the properties of this transition are determined by the number of states (discrete heading directions) that can be accessed by each agent. 14. NASA Space Radiation Program Integrative Risk Model Toolkit Science.gov (United States) Kim, Myung-Hee Y.; Hu, Shaowen; Plante, Ianik; Ponomarev, Artem L.; Sandridge, Chris 2015-01-01 NASA Space Radiation Program Element scientists have been actively involved in development of an integrative risk models toolkit that includes models for acute radiation risk and organ dose projection (ARRBOD), NASA space radiation cancer risk projection (NSCR), hemocyte dose estimation (HemoDose), GCR event-based risk model code (GERMcode), and relativistic ion tracks (RITRACKS), NASA radiation track image (NASARTI), and the On-Line Tool for the Assessment of Radiation in Space (OLTARIS). This session will introduce the components of the risk toolkit with opportunity for hands on demonstrations. The brief descriptions of each tools are: ARRBOD for Organ dose projection and acute radiation risk calculation from exposure to solar particle event; NSCR for Projection of cancer risk from exposure to space radiation; HemoDose for retrospective dose estimation by using multi-type blood cell counts; GERMcode for basic physical and biophysical properties for an ion beam, and biophysical and radiobiological properties for a beam transport to the target in the NASA Space Radiation Laboratory beam line; RITRACKS for simulation of heavy ion and delta-ray track structure, radiation chemistry, DNA structure and DNA damage at the molecular scale; NASARTI for modeling of the effects of space radiation on human cells and tissue by incorporating a physical model of tracks, cell nucleus, and DNA damage foci with image segmentation for the automated count; and OLTARIS, an integrated tool set utilizing HZETRN (High Charge and Energy Transport) intended to help scientists and engineers study the effects of space radiation on shielding materials, electronics, and biological systems. 15. Roy's Adaptation Model-Based Patient Education for Promoting the Adaptation of Hemodialysis Patients. Science.gov (United States) Afrasiabifar, Ardashir; Karimi, Zohreh; Hassani, Parkhideh 2013-07-01 In addition to physical adaptation and psychosocial adjustment to chronic renal disease, hemodialysis (HD) patients must also adapt to dialysis therapy plan. The aim of the present study was to examine the effect of Roy's adaptation model-based patient education on adaptation of HD patients. This study is a semi-experimental research that was conducted with the participation of all patients with end-stage renal disease referred to the dialysis unit of Shahid Beheshti Hospital of Yasuj city, 2010. A total of 59 HD patients were randomly allocated to two groups of test and control. Data were collected by a questionnaire based on the Roy's Adaptation Model (RAM). Validity and reliability of the questionnaire were approved. Patient education was determined by eight one-hour sessions over eight weeks. At the end of the education plan, the patients were given an educational booklet containing the main points of self-care for HD patients. The effectiveness of education plan was assessed two months after plan completion and data were compared with the pre-education scores. All analyses were conducted using the SPSS software (version 16) through descriptive and inferential statistics including correlation, t-test, ANOVA and ANCOVA tests. The results showed significant differences in the mean scores of physiological and self-concept models between the test and control groups (P = 0.01 and P = 0.03 respectively). Also a statistical difference (P = 0.04) was observed in the mean scores of the role function mode of both groups. There was no significant difference in the mean scores of interdependence modes between the two groups. RAM based patient education could improve the patients' adaptation in physiologic and self-concept modes. In addition to suggesting further research in this area, nurses are recommended to pay more attention in applying RAM in dialysis centers. 16. Modeling Clinical Radiation Responses in the IMRT Era Science.gov (United States) Schwartz, J. L.; Murray, D.; Stewart, R. D.; Phillips, M. H. 2014-03-01 The purpose of this review is to highlight the critical issues of radiobiological models, particularly as they apply to clinical radiation therapy. Developing models of radiation responses has a long history that continues to the present time. Many different models have been proposed, but in the field of radiation oncology, the linear-quadratic (LQ) model has had the most impact on the design of treatment protocols. Questions have been raised as to the value of the LQ model given that the biological assumption underlying it has been challenged by molecular analyses of cell and tissue responses to radiation. There are also questions as to use of the LQ model for hypofractionation, especially for high dose treatments using a single fraction. While the LQ model might over-estimate the effects of large radiation dose fractions, there is insufficient information to fully justify the adoption of alternative models. However, there is increasing evidence in the literature that non-targeted and other indirect effects of radiation sometimes produce substantial deviations from LQ-like dose-response curves. As preclinical and clinical hypofractionation studies accumulate, new or refined dose-response models that incorporate high-dose/fraction non-targeted and indirect effects may be required, but for now the LQ model remains a simple, useful tool to guide the design of treatment protocols. 17. Acoustic Model Adaptation for Indonesian Language Utterance Training System Directory of Open Access Journals (Sweden) Linda Indrayanti 2010-01-01 Full Text Available Problem statement: In order to build an utterance training system for Indonesian language, a speech recognition system designed for Indonesian is necessary. However, the system hardly works well due to the pronunciation variants of non-native utterances may lead to substitution/deletion error. This research investigated the pronunciation variant and proposes acoustic model adaptation to improve performance of the system. Approach: The proposed acoustic model adaptation worked in three steps: to analyze pronunciation variant with knowledge-based and data-derived methods; to align knowledge-based and data-derived results in order to list frequently mispronounced phones with their variants; to perform a state-clustering procedure with the list obtained from the second step. Further, three Speaker Adaptation (SA techniques were used in combination with the acoustic model adaptation and they are compared each other. In order to evaluate and tune the adaptation techniques, perceptual-based evaluation by three human raters is performed to obtain the "true"recognition results. Results: The proposed method achieved an average gain in Hit + Rejection (the percentage of correctly accepted and correctly rejected utterances by the system as the human raters do of 2.9 points and 2 points for native and non-native subjects, respectively, when compared with the system without adaptation. Average gains of 12.7 and 6.2 points for native and non-native students in Hit + Rejection were obtained by combining SA to the acoustic model adaptation. Conclusion/Recommendations: Performance evaluation of the adapted system demonstrated that the proposed acoustic model adaptation can improve Hit even though there is a slight increase of False Alarm (FA, the percentage of incorrectly accepted utterances by the system of which the human raters reject. The performance of the proposed acoustic model adaptation depends strongly on the effectiveness of state-clustering procedure 18. The behavior of adaptive bone-remodeling simulation models NARCIS (Netherlands) H.H. Weinans (Harrie); R. Huiskes (Rik); H.J. Grootenboer 1992-01-01 textabstractThe process of adaptive bone remodeling can be described mathematically and simulated in a computer model, integrated with the finite element method. In the model discussed here, cortical and trabecular bone are described as continuous materials with variable density. The remodeling rule 19. The Nominal Response Model in Computerized Adaptive Testing. Science.gov (United States) De Ayala, R. J. One important and promising application of item response theory (IRT) is computerized adaptive testing (CAT). The implementation of a nominal response model-based CAT (NRCAT) was studied. Item pool characteristics for the NRCAT as well as the comparative performance of the NRCAT and a CAT based on the three-parameter logistic (3PL) model were… 20. Adapting the Kirkpatrick Model to Technical Communication Products and Services. Science.gov (United States) Carliner, Saul 1997-01-01 Proposes a four-level model for adapting the Kirkpatrick model of training evaluation to suit technical manuals and services assessing: (1) user satisfaction; (2) user performance; (3) client performance; and (4) client satisfaction. Discusses assessing of the value of work, limitations in evaluating technical communication products, and the… 1. Model reference, sliding mode adaptive control for flexible structures Science.gov (United States) Yurkovich, S.; Ozguner, U.; Al-Abbass, F. 1988-01-01 A decentralized model reference adaptive approach using a variable-structure sliding model control has been developed for the vibration suppression of large flexible structures. Local models are derived based upon the desired damping and response time in a model-following scheme, and variable structure controllers are then designed which employ colocated angular rate and position feedback. Numerical simulations have been performed using NASA's flexible grid experimental apparatus. 2. Adaptive Simulated Annealing Based Protein Loop Modeling of Neurotoxins Institute of Scientific and Technical Information of China (English) 陈杰; 黄丽娜; 彭志红 2003-01-01 A loop modeling method, adaptive simulated annealing, for ab initio prediction of protein loop structures, as an optimization problem of searching the global minimum of a given energy function, is proposed. An interface-friendly toolbox-LoopModeller in Windows and Linux systems, VC++ and OpenGL environments is developed for analysis and visualization. Simulation results of three short-chain neurotoxins modeled by LoopModeller show that the method proposed is fast and efficient. 3. Adversary Model: Adaptive Chosen Ciphertext Attack with Timing Attack OpenAIRE 2014-01-01 We have introduced a novel adversary model in Chosen-Ciphertext Attack with Timing Attack (CCA2-TA) and it was a practical model because the model incorporates the timing attack. This paper is an extended paper for 'A Secure TFTP Protocol with Security Proofs'. Keywords - Timing Attack, Random Oracle Model, Indistinguishabilit, Chosen Plaintext Attack, CPA, Chosen Ciphertext Attack, IND-CCA1, Adaptive Chosen Ciphertext Attack, IND-CCA2, Trivial File Transfer Protocol, TFTP, Security, Trust, P... 4. Dark radiation from a unified dark fluid model CERN Document Server Geng, Chao-Qiang; Zhang, Xin 2014-01-01 We present a unified dark fluid model to describe the possible evolutionary behavior of\\Delta N_\\mathrm{eff}$in dark radiation. This model can be viewed as an interacting model for the dark sectors, in which dark matter interacts with dark radiation. We show that the evolution of$\\Delta N_\\mathrm{eff}$can be nicely explained without some drawbacks, such as the blowup of$\\Delta N_\\mathrm{eff}$at the late time and the interaction term at the early time. 5. Efficiently adapting graphical models for selectivity estimation DEFF Research Database (Denmark) Tzoumas, Kostas; Deshpande, Amol; Jensen, Christian S. 2013-01-01 of the selectivities of the constituent predicates. However, this independence assumption is more often than not wrong, and is considered to be the most common cause of sub-optimal query execution plans chosen by modern query optimizers. We take a step towards a principled and practical approach to performing...... cardinality estimation without making the independence assumption. By carefully using concepts from the field of graphical models, we are able to factor the joint probability distribution over all the attributes in the database into small, usually two-dimensional distributions, without a significant loss......Query optimizers rely on statistical models that succinctly describe the underlying data. Models are used to derive cardinality estimates for intermediate relations, which in turn guide the optimizer to choose the best query execution plan. The quality of the resulting plan is highly dependent... 6. Modeling and analysis of ground target radiation cross section Institute of Scientific and Technical Information of China (English) SHI Xiang; LOU GuoWei; LI XingGuo 2008-01-01 Based on the analysis of the passive millimeter wave (MMW) radiometer detection, the ground target radiation cross section is modeled as the new token for the target MMW radiant characteristics. Its ap-plication and actual testing are discussed and analyzed. The essence of passive MMW stealth is target radiation cross section reduction. 7. 3D Gray Radiative Properties of a Radiation Hydrodynamic Model of a YSO Accretion Shock Science.gov (United States) Ibgui, L.; de Sá, L.; Stehlé, C.; Chièze, J.-P.; Orlando, S.; Hubeny, I.; Lanz, T.; Matsakos, T.; González, M.; Bonito, R. 2014-09-01 We present preliminary results of radiative properties of a 1D gray radiation hydrodynamic (RHD) model of an accretion shock on a young stellar object (YSO). This model takes into account the transition between the collisional equilibrium regime (local thermodynamic equilibrium, LTE), and the coronal equilibrium regime. Based on the 1D planar structure, we built a 3D cylindrical one. Most notably, the post-shock region obtained in our case is far less extended (by a factor of 10 000) than the typical one obtained with models that assume gray optically thin radiative losses. Moreover, we find that the column is optically thin in its longitudinal dimension, and in the transverse dimension, except over an extremely narrow region (≲ 700 m). Consequently, still under the gray assumption, the photons emitted by the hot slab can propagate through the column and escape freely in all directions, including towards the chromosphere. The radiation flux has therefore components that are perpendicular to the accretion column, which demonstrates that a multidimensional (2D or 3D) radiative model is necessary for such a cylindrical structure. This study needs to be taken forward and expanded, by improving the radiative treatment of the RHD model, through relaxation of both the gray and the LTE approximations for the calculation of opacities, in order to clarify the structure of the post-shock region, which is a major source of emission probed by observations. 8. Adapting AIC to conditional model selection NARCIS (Netherlands) M. van Ommen (Matthijs) 2012-01-01 textabstractIn statistical settings such as regression and time series, we can condition on observed information when predicting the data of interest. For example, a regression model explains the dependent variables$y_1, \\ldots, y_n$in terms of the independent variables$x_1, \\ldots, x_n. 9. An Adaptive Trust Model of Web Services Institute of Scientific and Technical Information of China (English) SU Jin-dian; GUO He-qing; GAO Yin 2005-01-01 This paper proposes a dynamic Web service trust(WS Trust ) model, and some corresponding trust metric evaluation algorithms. The main goal is to evaluate the trustworthiness and predict the future behaviors of entities in order to help users find trustworthy Web service providers and prevent users from providing unfair ratings against service providers. 10. Hybrid and adaptive meta-model-based global optimization Science.gov (United States) Gu, J.; Li, G. Y.; Dong, Z. 2012-01-01 As an efficient and robust technique for global optimization, meta-model-based search methods have been increasingly used in solving complex and computation intensive design optimization problems. In this work, a hybrid and adaptive meta-model-based global optimization method that can automatically select appropriate meta-modelling techniques during the search process to improve search efficiency is introduced. The search initially applies three representative meta-models concurrently. Progress towards a better performing model is then introduced by selecting sample data points adaptively according to the calculated values of the three meta-models to improve modelling accuracy and search efficiency. To demonstrate the superior performance of the new algorithm over existing search methods, the new method is tested using various benchmark global optimization problems and applied to a real industrial design optimization example involving vehicle crash simulation. The method is particularly suitable for design problems involving computation intensive, black-box analyses and simulations. 11. Role of AKT and ERK pathways in controlling sensitivity to ionizing radiation and adaptive response induced by low-dose radiation in human immune cells. Science.gov (United States) Park, Hyung Sun; You, Ga Eun; Yang, Kwang Hee; Kim, Ji Young; An, Sungkwan; Song, Jie-Young; Lee, Su-Jae; Lim, Young-Khi; Nam, Seon Young 2015-12-01 Despite many studies of the effect of ionizing radiation, biological mechanisms of action might differ greatly depend on dose, dose rate, and cell type. This study was performed to explore the effects of low- and high-dose radiation in human immune cell lines. We examined cell sensitivity after irradiation with 0.05, 0.1, or 2Gy in two normal cell lines and three tumor cell lines. Low-dose radiation of 0.05 and 0.1Gy had no effect on cell survival in any tested cell line, with the exception of IM-9 cells, whose viability was transiently increased. However, IM-9 and C1R-sB7 cells were very sensitive to high-dose radiation-induced cell death, whereas Jurkat and JM1 cells showed moderate sensitivity, and THP-1 cells were completely resistant. This radiosensitivity was correlated with basal AKT activation, which is induced by phosphorylation. In radiosensitive IM-9 cells, priming with chronic low-dose irradiation blocked cell death induced by high-dose radiation challenge via inhibition of caspase activation and PARP cleavage. AKT phosphorylation was not altered in IM-9 cells, but ERK phosphorylation was greatly elevated immediately after chronic low-dose irradiation. Taken together, our results suggest that the different responses of normal and tumor cells to low-dose and high-dose radiation depend on AKT activation, which is regulated by protein phosphatase 2 (PP2A). In radiosensitive normal cells lacking basal AKT activity, chronic low-dose radiation increases activation of the ERK pathway, which plays an important role in the adaptive response to radiation, providing a very important insight into understanding the effects of ionizing radiation on health. Copyright © 2015 Elsevier GmbH. All rights reserved. 12. An Analytic Radiative-Convective Model for Planetary Atmospheres CERN Document Server Robinson, Tyler D; 10.1088/0004-637X/757/1/104 2012-01-01 We present an analytic 1-D radiative-convective model of the thermal structure of planetary atmospheres. Our model assumes that thermal radiative transfer is gray and can be represented by the two-stream approximation. Model atmospheres are assumed to be in hydrostatic equilibrium, with a power law scaling between the atmospheric pressure and the gray thermal optical depth. The convective portions of our models are taken to follow adiabats that account for condensation of volatiles through a scaling parameter to the dry adiabat. By combining these assumptions, we produce simple, analytic expressions that allow calculations of the atmospheric pressure-temperature profile, as well as expressions for the profiles of thermal radiative flux and convective flux. We explore the general behaviors of our model. These investigations encompass (1) worlds where atmospheric attenuation of sunlight is weak, which we show tend to have relatively high radiative-convective boundaries, (2) worlds with some attenuation of sunli... 13. The Importance of Formalizing Computational Models of Face Adaptation Aftereffects Science.gov (United States) Ross, David A.; Palmeri, Thomas J. 2016-01-01 Face adaptation is widely used as a means to probe the neural representations that support face recognition. While the theories that relate face adaptation to behavioral aftereffects may seem conceptually simple, our work has shown that testing computational instantiations of these theories can lead to unexpected results. Instantiating a model of face adaptation not only requires specifying how faces are represented and how adaptation shapes those representations but also specifying how decisions are made, translating hidden representational states into observed responses. Considering the high-dimensionality of face representations, the parallel activation of multiple representations, and the non-linearity of activation functions and decision mechanisms, intuitions alone are unlikely to succeed. If the goal is to understand mechanism, not simply to examine the boundaries of a behavioral phenomenon or correlate behavior with brain activity, then formal computational modeling must be a component of theory testing. To illustrate, we highlight our recent computational modeling of face adaptation aftereffects and discuss how models can be used to understand the mechanisms by which faces are recognized. PMID:27378960 14. Adaptive Radiation in Socially Advanced Stem-Group Ants from the Cretaceous. Science.gov (United States) Barden, Phillip; Grimaldi, David A 2016-02-22 Across terrestrial ecosystems, modern ants are ubiquitous. As many as 94 out of every 100 individual arthropods in rainforests are ants, and they constitute up to 15% of animal biomass in the Amazon. Moreover, ants are pervasive agents of natural selection as over 10,000 arthropod species are specialized inquilines or myrmecomorphs living among ants or defending themselves through mimicry. Such impact is traditionally explained by sociality: ants are the first major group of ground-dwelling predatory insects to become eusocial, increasing efficiency of tasks and establishing competitive superiority over solitary species. A wealth of specimens from rich deposits of 99 million-year-old Burmese amber resolves ambiguity regarding sociality and diversity in the earliest ants. The stem-group genus Gerontoformica maintained distinct reproductive castes including morphotypes unknown in solitary aculeate (stinging) wasps, providing insight into early behavior. We present rare aggregations of workers, indicating group recruitment as well as an instance of interspecific combat; such aggression is a social feature of modern ants. Two species and an unusual new genus are described, further expanding the remarkable diversity of early ants. Stem-group ants are recovered as a paraphyletic assemblage at the base of modern lineages varying greatly in size, form, and mouthpart structure, interpreted here as an adaptive radiation. Though Cretaceous stem-group ants were eusocial and adaptively diverse, we hypothesize that their extinction resulted from the rise of competitively superior crown-group taxa that today form massive colonies, consistent with Wilson and Hölldobler's concept of "dynastic succession." 15. Dosimetric advantages of a clinical daily adaptive plan selection strategy compared with a non-adaptive strategy in cervical cancer radiation therapy. Science.gov (United States) van de Schoot, Agustinus J A J; de Boer, Peter; Visser, Jorrit; Stalpers, Lukas J A; Rasch, Coen R N; Bel, Arjan 2017-05-01 Radiation therapy (RT) using a daily plan selection adaptive strategy can be applied to account for interfraction organ motion while limiting organ at risk dose. The aim of this study was to quantify the dosimetric consequences of daily plan selection compared with non-adaptive RT in cervical cancer. Ten consecutive patients who received pelvic irradiation, planning CTs (full and empty bladder), weekly post-fraction CTs and pre-fraction CBCTs were included. Non-adaptive plans were generated based on the PTV defined using the full bladder planning CT. For the adaptive strategy, multiple PTVs were created based on both planning CTs by ITVs of the primary CTVs (i.e., GTV, cervix, corpus-uterus and upper part of the vagina) and corresponding library plans were generated. Daily CBCTs were rigidly aligned to the full bladder planning CT for plan selection. For daily plan recalculation, selected CTs based on initial similarity were deformably registered to CBCTs. Differences in daily target coverage (D98% > 95%) and in V0.5Gy, V1.5Gy, V2Gy, D50% and D2% for rectum, bladder and bowel were assessed. Non-adaptive RT showed inadequate primary CTV coverage in 17% of the daily fractions. Plan selection compensated for anatomical changes and improved primary CTV coverage significantly (p adaptive RT, plan selection decreased the fraction dose to rectum and bowel indicated by significant (p adaptive strategy led to inadequate target coverage for individual patients. Daily plan selection corrected for day-to-day anatomical variations and resulted in adequate target coverage in all fractions. The dose to bowel and rectum was decreased significantly when applying adaptive RT. 16. SOD2-mediated adaptive responses induced by low-dose ionizing radiation via TNF signaling and amifostine. Science.gov (United States) Murley, J S; Baker, K L; Miller, R C; Darga, T E; Weichselbaum, R R; Grdina, D J 2011-11-15 Manganese superoxide dismutase (SOD2)-mediated adaptive processes that protect against radiation-induced micronucleus formation can be induced in cells after a 2-Gy exposure by previously exposing them to either low-dose ionizing radiation (10cGy) or WR1065 (40μM), the active thiol form of amifostine. Although both adaptive processes culminate in elevated levels of SOD2 enzymatic activity, the underlying pathways differ in complexity, with the tumor necrosis factor α (TNFα) signaling pathway implicated in the low-dose radiation-induced response, but not in the thiol-induced pathway. The goal of this study was the characterization of the effects of TNFα receptors 1 and 2 (TNFR1, TNFR2) on the adaptive responses induced by low-dose irradiation or thiol exposure using micronucleus formation as an endpoint. BFS-1 wild-type cells with functional TNFR1 and 2 were exposed 24h before a 2-Gy dose of ionizing radiation to either 10cGy or a 40μM dose of WR1065. BFS2C-SH02 cells, defective in TNFR1, and BFS2C-SH22 cells, defective in both TNFR1 and TNFR2 and generated from BFS2C-SH02 cells by transfection with a murine TNFR2-targeting vector and confirmed to be TNFR2 defective by quantitative PCR, were also exposed under similar conditions for comparison. A 10-cGy dose of radiation induced a significant elevation in SOD2 activity in BFS-1 (Pradiation-induced micronuclei was observed in each cell line when exposure to a 2-Gy challenge dose of radiation occurred during the period of maximal elevation in SOD2 activity. However, this adaptive effect was completely inhibited if the cells were transfected 24h before low-dose radiation or thiol exposure with SOD2 siRNA. Under the conditions tested, TNFR1 and 2 inhibition negatively affected the low-dose radiation-induced but not the thiol-induced adaptive responses observed to be mediated by elevations in SOD2 activity. Copyright © 2011 Elsevier Inc. All rights reserved. 17. Cloud-Aerosol-Radiation (CAR ensemble modeling system Directory of Open Access Journals (Sweden) X.-Z. Liang 2013-04-01 Full Text Available A Cloud-Aerosol-Radiation (CAR ensemble modeling system has been developed to incorporate the largest choices of alternative parameterizations for cloud properties (cover, water, radius, optics, geometry, aerosol properties (type, profile, optics, radiation transfers (solar, infrared, and their interactions. These schemes form the most comprehensive collection currently available in the literature, including those used by the world leading general circulation models (GCMs. The CAR provides a unique framework to determine (via intercomparison across all schemes, reduce (via optimized ensemble simulations, and attribute specific key factors for (via physical process sensitivity analyses the model discrepancies and uncertainties in representing greenhouse gas, aerosol and cloud radiative forcing effects. This study presents a general description of the CAR system and illustrates its capabilities for climate modeling applications, especially in the context of estimating climate sensitivity and uncertainty range caused by cloud-aerosol-radiation interactions. For demonstration purpose, the evaluation is based on several CAR standalone and coupled climate model experiments, each comparing a limited subset of the full system ensemble with up to 896 members. It is shown that the quantification of radiative forcings and climate impacts strongly depends on the choices of the cloud, aerosol and radiation schemes. The prevailing schemes used in current GCMs are likely insufficient in variety and physically biased in a significant way. There exists large room for improvement by optimally combining radiation transfer with cloud property schemes. 18. Preliminary results of a three-dimensional radiative transfer model Energy Technology Data Exchange (ETDEWEB) OHirok, W. [Univ. of California, Santa Barbara, CA (United States) 1995-09-01 Clouds act as the primary modulator of the Earths radiation at the top of the atmosphere, within the atmospheric column, and at the Earth`s surface. They interact with both shortwave and longwave radiation, but it is primarily in the case of shortwave where most of the uncertainty lies because of the difficulties in treating scattered solar radiation. To understand cloud-radiative interactions, radiative transfer models portray clouds as plane-parallel homogeneous entities to ease the computational physics. Unfortunately, clouds are far from being homogeneous, and large differences between measurement and theory point to a stronger need to understand and model cloud macrophysical properties. In an attempt to better comprehend the role of cloud morphology on the 3-dimensional radiation field, a Monte Carlo model has been developed. This model can simulate broadband shortwave radiation fluxes while incorporating all of the major atmospheric constituents. The model is used to investigate the cloud absorption anomaly where cloud absorption measurements exceed theoretical estimates and to examine the efficacy of ERBE measurements and cloud field experiments. 3 figs. 19. Accuracy tests of radiation schemes used in hot Jupiter Global Circulation Models CERN Document Server Amundsen, David Skålid; Tremblin, Pascal; Manners, James; Hayek, Wolfgang; Mayne, N J; Acreman, David M 2014-01-01 The treatment of radiation transport in global circulation models (GCMs) is crucial to correctly describe Earth and exoplanet atmospheric dynamics processes. The two-stream approximation and correlated-k$method are currently state-of-the-art approximations applied in both Earth and hot Jupiter GCM radiation schemes to facilitate rapid calculation of fluxes and heating rates. Their accuracy have been tested extensively for Earth-like conditions, but verification of the methods' applicability to hot Jupiter-like conditions is lacking in the literature. We are adapting the UK Met Office GCM, the Unified Model (UM), for the study of hot Jupiters, and present in this work the adaptation of the Edwards-Slingo radiation scheme based on the two-stream approximation and the correlated-$k\$ method. We discuss the calculation of absorption coefficients from high temperature line lists and highlight the large uncertainty in the pressure-broadened line widths. We compare fluxes and heating rates obtained with our adapted...
20. A space radiation shielding model of the Martian radiation environment experiment (MARIE)
Science.gov (United States)
Atwell, W.; Saganti, P.; Cucinotta, F. A.; Zeitlin, C. J.
2004-01-01
The 2001 Mars Odyssey spacecraft was launched towards Mars on April 7, 2001. Onboard the spacecraft is the Martian radiation environment experiment (MARIE), which is designed to measure the background radiation environment due to galactic cosmic rays (GCR) and solar protons in the 20-500 MeV/n energy range. We present an approach for developing a space radiation-shielding model of the spacecraft that includes the MARIE instrument in the current mapping phase orientation. A discussion is presented describing the development and methodology used to construct the shielding model. For a given GCR model environment, using the current MARIE shielding model and the high-energy particle transport codes, dose rate values are compared with MARIE measurements during the early mapping phase in Mars orbit. The results show good agreement between the model calculations and the MARIE measurements as presented for the March 2002 dataset. c2003 COSPAR. Published by Elsevier Ltd. All rights reserved.
1. Adaptive plasticity model for bucket foundations
DEFF Research Database (Denmark)
Ibsen, Lars Bo; Barari, Amin; Larsen, Kim A.
2014-01-01
Based on experimental investigations, the literature proposes different methods for modeling the behavior and capacity of foundations subjected to combined loading. Generally, two methods are used to predict the behavior of foundations: traditional approaches and hardening plasticity solutions....... The first method is only capable of determining the capacity of the foundations and not the prepeak behavior. Thus, a new strain-hardening criterion is developed by calibrating failure criteria by employing data from small-scale tests on bucket foundations subjected to static loads. The shape of the yield...
2. A new thermal comfort approach comparing adaptive and PMV models
Energy Technology Data Exchange (ETDEWEB)
Orosa, Jose A. [Universidade da Coruna, Departamento de Energia y P. M. Paseo de Ronda, n :51, 15011. A Coruna (Spain); Oliveira, Armando C. [Universidade do Porto, Faculdade de Engenharia, New Energy Tec. Unit. Rua Dr Roberto Frias, 4200-465 Porto (Portugal)
2011-03-15
In buildings with heating, ventilation, and air-conditioning (HVAC), the Predicted Mean Vote index (PMV) was successful at predicting comfort conditions, whereas in naturally ventilated buildings, only adaptive models provide accurate predictions. On the other hand, permeable coverings can be considered as a passive control method of indoor conditions and, consequently, have implications in the perception of indoor air quality, local thermal comfort, and energy savings. These energy savings were measured in terms of the set point temperature established in accordance with adaptive methods. Problems appear when the adaptive model suggests the same neutral temperature for ambiences with the same indoor temperature but different relative humidities. In this paper, a new design of the PMV model is described to compare the neutral temperature to real indoor conditions. Results showed that this new PMV model tends to overestimate thermal neutralities but with a lower value than Fanger's PMV index. On the other hand, this new PMV model considers indoor relative humidity, showing a clear differentiation of indoor ambiences in terms of it, unlike adaptive models. Finally, spaces with permeable coverings present indoor conditions closer to thermal neutrality, with corresponding energy savings. (author)
3. Recent models for adaptive personality differences: a review
Science.gov (United States)
Dingemanse, Niels J.; Wolf, Max
2010-01-01
In this paper we review recent models that provide adaptive explanations for animal personalities: individual differences in behaviour (or suites of correlated behaviours) that are consistent over time or contexts. We start by briefly discussing patterns of variation in behaviour that have been documented in natural populations. In the main part of the paper we discuss models for personality differences that (i) explain animal personalities as adaptive behavioural responses to differences in state, (ii) investigate how feedbacks between state and behaviour can stabilize initial differences among individuals and (iii) provide adaptive explanations for animal personalities that are not based on state differences. Throughout, we focus on two basic questions. First, what is the basic conceptual idea underlying the model? Second, what are the key assumptions and predictions of the model? We conclude by discussing empirical features of personalities that have not yet been addressed by formal modelling. While this paper is primarily intended to guide empiricists through current adaptive theory, thereby stimulating empirical tests of these models, we hope it also inspires theoreticians to address aspects of personalities that have received little attention up to now. PMID:21078647
4. Adaptive Estimation of Heteroscedastic Money Demand Model of Pakistan
Directory of Open Access Journals (Sweden)
2007-07-01
Full Text Available For the problem of estimation of Money demand model of Pakistan, money supply (M1 shows heteroscedasticity of the unknown form. For estimation of such model we compare two adaptive estimators with ordinary least squares estimator and show the attractive performance of the adaptive estimators, namely, nonparametric kernel estimator and nearest neighbour regression estimator. These comparisons are made on the basis standard errors of the estimated coefficients, standard error of regression, Akaike Information Criteria (AIC value, and the Durban-Watson statistic for autocorrelation. We further show that nearest neighbour regression estimator performs better when comparing with the other nonparametric kernel estimator.
5. Adaptive network models of collective decision making in swarming systems
CERN Document Server
Chen, Li; Gross, Thilo
2015-01-01
We consider a class of adaptive network models where links can only be created or deleted between nodes in different states. These models provide an approximate description of a set of systems where nodes represent agents moving in physical or abstract space, the state of each node represents the agent's heading direction, and links indicate mutual awareness. We show analytically that the adaptive network description captures the phase transition to collective motion in swarming systems and that the properties of this transition are determined by the number of states (discrete heading directions) that can be accessed by each agent.
6. The Adaptive LASSO Spline Estimation of Single-Index Model
Institute of Scientific and Technical Information of China (English)
LU Yiqiang; ZHANG Riquan; HU Bin
2016-01-01
In this paper,based on spline approximation,the authors propose a unified variable selection approach for single-index model via adaptive L1 penalty.The calculation methods of the proposed estimators are given on the basis of the known lars algorithm.Under some regular conditions,the authors demonstrate the asymptotic properties of the proposed estimators and the oracle properties of adaptive LASSO (aLASSO) variable selection.Simulations are used to investigate the performances of the proposed estimator and illustrate that it is effective for simultaneous variable selection as well as estimation of the single-index models.
7. Experimental Evolution of UV-C Radiation Tolerance: Emergence of Adaptive and Non-Adaptive Traits in Escherichia coli Under Differing Flux Regimes
Science.gov (United States)
Moffet, A.; Okansinski, A.; Sloan, C.; Grace, J. M.; Paulino-Lima, I. G.; Gentry, D.; Rothschild, L. J.; Camps, M.
2014-12-01
8. The Nonlinear Sigma Model With Distributed Adaptive Mesh Refinement
CERN Document Server
Liebling, S L
2004-01-01
An adaptive mesh refinement (AMR) scheme is implemented in a distributed environment using Message Passing Interface (MPI) to find solutions to the nonlinear sigma model. Previous work studied behavior similar to black hole critical phenomena at the threshold for singularity formation in this flat space model. This work is a follow-up describing extensions to distribute the grid hierarchy and presenting tests showing the correctness of the model.
9. Radiation Belt Environment Model: Application to Space Weather and Beyond
Science.gov (United States)
Fok, Mei-Ching H.
2011-01-01
Understanding the dynamics and variability of the radiation belts are of great scientific and space weather significance. A physics-based Radiation Belt Environment (RBE) model has been developed to simulate and predict the radiation particle intensities. The RBE model considers the influences from the solar wind, ring current and plasmasphere. It takes into account the particle drift in realistic, time-varying magnetic and electric field, and includes diffusive effects of wave-particle interactions with various wave modes in the magnetosphere. The RBE model has been used to perform event studies and real-time prediction of energetic electron fluxes. In this talk, we will describe the RBE model equation, inputs and capabilities. Recent advancement in space weather application and artificial radiation belt study will be discussed as well.
10. Comparison of the performance of net radiation calculation models
DEFF Research Database (Denmark)
Kjærsgaard, Jeppe Hvelplund; Cuenca, R H; Martinez-Cob, A
2009-01-01
values of net radiation were calculated using three net outgoing long-wave radiation models and compared to measured values. Four meteorological datasets representing two climate regimes, a sub-humid, high-latitude environment and a semi-arid mid-latitude environment, were used to test the models...... meteorological input data is limited. Model predictions were found to have a higher bias and scatter when using summed calculated hourly time steps compared to using daily input data.......Daily values of net radiation are used in many applications of crop-growth modeling and agricultural water management. Measurements of net radiation are not part of the routine measurement program at many weather stations and are commonly estimated based on other meteorological parameters. Daily...
11. Fast and simple model for atmospheric radiative transfer
NARCIS (Netherlands)
Seidel, F.C.; Kokhanovsky, A.A.; Schaepman, M.E.
2010-01-01
Radiative transfer models (RTMs) are of utmost importance for quantitative remote sensing, especially for compensating atmospheric perturbation. A persistent trade-off exists between approaches that prefer accuracy at the cost of computational complexity, versus those favouring simplicity at the
12. Radiative Transfer Model for Translucent Slab Ice on Mars
Science.gov (United States)
Andrieu, F.; Schmidt, F.; Douté, S.; Schmitt, B.; Brissaud, O.
2016-09-01
We developed a radiative transfer model that simulates in VIS/NIR the bidirectional reflectance of a contaminated slab layer of ice overlaying a granular medium, under geometrical optics conditions to study martian ices.
13. Discrete Event Simulation Modeling of Radiation Medicine Delivery Methods
Energy Technology Data Exchange (ETDEWEB)
Paul M. Lewis; Dennis I. Serig; Rick Archer
1998-12-31
The primary objective of this work was to evaluate the feasibility of using discrete event simulation (DES) modeling to estimate the effects on system performance of changes in the human, hardware, and software elements of radiation medicine delivery methods.
14. Use of the adaptive classifier for determination of LD50 in the acute radiation disease.
Science.gov (United States)
Vodicka, I; Hanus, J; Hradil, J
1989-01-01
In experiments on female Wistar rats a new method for the determination of LD50 is demonstrated and compared with the classical probit method using the same experimental animals. The method is applicable for the computation of LD50 and analogical quantities in man, too. The method is based on the application of an adaptive logical circuit (ADALINE) trained for the dichotomous prognostic classification of irradiated individuals quod vitam according to a set of clinical and laboratory indicators registered on the third day after irradiation. After the training procedure has been finished, the classifier makes possible an individual prognosis of survival or death. The analogue output signal according to which the classification is performed changes continually from negative to positive values and exhibits S-shaped relation to the radiation dose. Its zero value corresponds to the position of LD50 on the abscissa. For the construction of the searched function, i.e. for the optimum approximation of experimentally obtained values of the output signal, the method of the changeable polyhedron was applied belonging to the optimalization numerical methods used in the regulation technics. The computed value of LD50 was 7.80 Gy in rats very closely corresponding with the value 7.61 Gy determined by means of the classical probit method.
15. A framework for automated contour quality assurance in radiation therapy including adaptive techniques
Science.gov (United States)
Altman, M. B.; Kavanaugh, J. A.; Wooten, H. O.; Green, O. L.; DeWees, T. A.; Gay, H.; Thorstad, W. L.; Li, H.; Mutic, S.
2015-07-01
Contouring of targets and normal tissues is one of the largest sources of variability in radiation therapy treatment plans. Contours thus require a time intensive and error-prone quality assurance (QA) evaluation, limitations which also impair the facilitation of adaptive radiotherapy (ART). Here, an automated system for contour QA is developed using historical data (the ‘knowledge base’). A pilot study was performed with a knowledge base derived from 9 contours each from 29 head-and-neck treatment plans. Size, shape, relative position, and other clinically-relevant metrics and heuristically derived rules are determined. Metrics are extracted from input patient data and compared against rules determined from the knowledge base; a computer-learning component allows metrics to evolve with more input data, including patient specific data for ART. Nine additional plans containing 42 unique contouring errors were analyzed. 40/42 errors were detected as were 9 false positives. The results of this study imply knowledge-based contour QA could potentially enhance the safety and effectiveness of RT treatment plans as well as increase the efficiency of the treatment planning process, reducing labor and the cost of therapy for patients.
16. Convergent evolution of behavior in an adaptive radiation of Hawaiian web-building spiders.
Science.gov (United States)
Blackledge, Todd A; Gillespie, Rosemary G
2004-11-16
Species in ecologically similar habitats often display patterns of divergence that are strikingly comparable, suggesting that natural selection can lead to predictable evolutionary change in communities. However, the relative importance of selection as an agent mediating in situ diversification, versus dispersal between habitats, cannot be addressed without knowledge of phylogenetic history. We used an adaptive radiation of spiders within the Hawaiian Islands to test the prediction that species of spiders on different islands would independently evolve webs with similar architectures. Tetragnatha spiders are the only nocturnal orb-weaving spiders endemic to the Hawaiian archipelago, and multiple species of orb-weaving Tetragnatha co-occur within mesic and wet forest habitats on each of the main islands. Therefore, comparison of web architectures spun by spiders on different islands allowed study of replicated evolutionary events of past behavioral diversification. We found that species within each island construct webs with architectures that differ from one another. However, pairs of species on different islands, "ethotypes," share remarkable similarities in web architectures. Phylogenetic analysis demonstrated that the species comprising these ethotypes evolved independent of one another. Our study illustrates the high degree of predictability that can be exhibited by the evolutionary diversification of complex behaviors. However, not all web architectures were shared between islands, demonstrating that unique effects also have played an important role in the historical diversification of behavior.
17. Radiative heat transfer between metallic gratings using Fourier modal method with adaptive spatial resolution
Science.gov (United States)
Messina, Riccardo; Noto, Antonio; Guizal, Brahim; Antezza, Mauro
2017-03-01
We calculate the radiative heat transfer between two identical metallic one-dimensional lamellar gratings. To this aim we present and exploit a modification to the widely used Fourier modal method, known as adaptive spatial resolution, based on a stretch of the coordinate associated with the periodicity of the grating. We first show that this technique dramatically improves the rate of convergence when calculating the heat flux, allowing us to explore smaller separations. We then present a study of heat flux as a function of the grating height, highlighting a remarkable amplification of the exchanged energy, ascribed to the appearance of spoof-plasmon modes, whose behavior is also spectrally investigated. Differently from previous works, our method allows us to explore a range of grating heights extending over several orders of magnitude. By comparing our results to recent studies we find a consistent quantitative disagreement with some previously obtained results going up to 50%. In some cases, this disagreement is explained in terms of an incorrect connection between the reflection operators of the two gratings.
Science.gov (United States)
Stapleton, Scott; Gries, Thomas; Waas, Anthony M.; Pineda, Evan J.
2014-01-01
Enhanced finite elements are elements with an embedded analytical solution that can capture detailed local fields, enabling more efficient, mesh independent finite element analysis. The shape functions are determined based on the analytical model rather than prescribed. This method was applied to adhesively bonded joints to model joint behavior with one element through the thickness. This study demonstrates two methods of maintaining the fidelity of such elements during adhesive non-linearity and cracking without increasing the mesh needed for an accurate solution. The first method uses adaptive shape functions, where the shape functions are recalculated at each load step based on the softening of the adhesive. The second method is internal mesh adaption, where cracking of the adhesive within an element is captured by further discretizing the element internally to represent the partially cracked geometry. By keeping mesh adaptations within an element, a finer mesh can be used during the analysis without affecting the global finite element model mesh. Examples are shown which highlight when each method is most effective in reducing the number of elements needed to capture adhesive nonlinearity and cracking. These methods are validated against analogous finite element models utilizing cohesive zone elements.
19. Parameterization of clouds and radiation in climate models
Energy Technology Data Exchange (ETDEWEB)
Roeckner, E. [Max Planck Institute for Meterology, Hamburg (Germany)
1995-09-01
Clouds are a very important, yet poorly modeled element in the climate system. There are many potential cloud feedbacks, including those related to cloud cover, height, water content, phase change, and droplet concentration and size distribution. As a prerequisite to studying the cloud feedback issue, this research reports on the simulation and validation of cloud radiative forcing under present climate conditions using the ECHAM general circulation model and ERBE top-of-atmosphere radiative fluxes.
20. Validation of elastic cross section models for space radiation applications
Science.gov (United States)
Werneth, C. M.; Xu, X.; Norman, R. B.; Ford, W. P.; Maung, K. M.
2017-02-01
The space radiation field is composed of energetic particles that pose both acute and long-term risks for astronauts in low earth orbit and beyond. In order to estimate radiation risk to crew members, the fluence of particles and biological response to the radiation must be known at tissue sites. Given that the spectral fluence at the boundary of the shielding material is characterized, radiation transport algorithms may be used to find the fluence of particles inside the shield and body, and the radio-biological response is estimated from experiments and models. The fidelity of the radiation spectrum inside the shield and body depends on radiation transport algorithms and the accuracy of the nuclear cross sections. In a recent study, self-consistent nuclear models based on multiple scattering theory that include the option to study relativistic kinematics were developed for the prediction of nuclear cross sections for space radiation applications. The aim of the current work is to use uncertainty quantification to ascertain the validity of the models as compared to a nuclear reaction database and to identify components of the models that can be improved in future efforts.
1. Modelling low energy electron interactions for biomedical uses of radiation
Energy Technology Data Exchange (ETDEWEB)
Fuss, M; Garcia, G [Instituto de Fisica Fundamental, Consejo Superior de Investigaciones CientIficas (CSIC), Serrano 113-bis, 28006 Madrid (Spain); Munoz, A; Oller, J C [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT), Avenida Complutense 22, 28040 Madrid (Spain); Blanco, F [Departamento de Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid, Avenida Complutense s.n., 28040 Madrid (Spain); Limao-Vieira, P [Departamento de Fisica, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Huerga, C; Tellez, M [Hospital Universitario La Paz, paseo de la Castellana 261, 28046 Madrid (Spain); Hubin-Fraskin, M J [Department of Chemistry, University of Liege, 4000 Liege 1 (Belgium); Nixon, K; Brunger, M, E-mail: [email protected] [School of Chemistry, Physics and Earth Sciences, Flinders University, GPO Box 2100, Adelaide, SA 5001 (Australia)
2009-11-15
Current radiation based medical applications in the field of radiotherapy, radio-diagnostic and radiation protection require modelling single particle interactions at the molecular level. Due to their relevance in radiation damage to biological systems, special attention should be paid to include the effect of low energy secondary electrons. In this study we present a single track simulation procedure for photons and electrons which is based on reliable experimental and theoretical cross section data and the energy loss distribution functions derived from our experiments. The effect of including secondary electron interactions in this model will be discussed.
2. Modeling and Adaptive Control of a Planar Parallel Mechanism
Institute of Scientific and Technical Information of China (English)
敖银辉; 陈新
2004-01-01
Dynamic model and control strategy of parallel mechanism have always been a problem in robotics research. In this paper,different dynamics formulation methods are discussed first, A model of redundant driven parallel mechanism with a planar parallel manipulator is then constructed as an example. A nonlinear adaptive control method is introduced. Matrix pseudo-inversion is used to get a desired actuator torque from a desired end-effector coordinate while the feedback torque is directly calculated in the actuator space. This treatment avoids forward kinematics computation that is very difficult in a parallel mechanism. Experiments with PID together with the descibed adaptive control strategy were carried out for a planar parallel mechanism. The results show that the proposed adaptive controller outperforms conventional PID methods in tracking desired input at a high speed,
3. Stock market modeling and forecasting a system adaptation approach
CERN Document Server
Zheng, Xiaolian
2013-01-01
Stock Market Modeling translates experience in system adaptation gained in an engineering context to the modeling of financial markets with a view to improving the capture and understanding of market dynamics. The modeling process is considered as identifying a dynamic system in which a real stock market is treated as an unknown plant and the identification model proposed is tuned by feedback of the matching error. Like a physical system, a stock market exhibits fast and slow dynamics corresponding to internal (such as company value and profitability) and external forces (such as investor sentiment and commodity prices) respectively. The framework presented here, consisting of an internal model and an adaptive filter, is successful at considering both fast and slow market dynamics. A double selection method is efficacious in identifying input factors influential in market movements, revealing them to be both frequency- and market-dependent. The authors present work on both developed and developing markets ...
4. Student Modelling in Adaptive E-Learning Systems
Directory of Open Access Journals (Sweden)
Clemens Bechter
2011-09-01
Full Text Available Most e-Learning systems provide web-based learning so that students can access the same online courses via the Internet without adaptation, based on each student's profile and behavior. In an e-Learning system, one size does not fit all. Therefore, it is a challenge to make e-Learning systems that are suitably “adaptive”. The aim of adaptive e-Learning is to provide the students the appropriate content at the right time, means that the system is able to determine the knowledge level, keep track of usage, and arrange content automatically for each student for the best learning result. This study presents a proposed system which includes major adaptive features based on a student model. The proposed system is able to initialize the student model for determining the knowledge level of a student when the student registers for the course. After a student starts learning the lessons and doing many activities, the system can track information of the student until he/she takes a test. The student’s knowledge level, based on the test scores, is updated into the system for use in the adaptation process, which combines the student model with the domain model in order to deliver suitable course contents to the students. In this study, the proposed adaptive e-Learning system is implemented on an “Introduction to Java Programming Language” course, using LearnSquare software. After the system was tested, the results showed positive feedback towards the proposed system, especially in its adaptive capability.
5. Animal Models of Ionizing Radiation Damage
Science.gov (United States)
1992-01-01
Haggbloom, and R.A. Gazzara, Effects of Hippocampal X-irradiation-Produced Granule-Cell Agenesis on Instrumental Runway Performance in Rats, Physiol...Bowden, and J.P. Wyatt, A Pathway To Pulmonary Fibrosis: An Ultrastructural Study Of Mouse and Rat Following Radiation to the Whole Body and Hemithorax...532-536, 1956. 27. Brooks, P.M., E.O. Richey, and J.E. Pickering, Prompt Pulmonary Ventilation and Oxygen Consumption Changes in Rhesus Monkeys
6. Modeling radiative properties of nanoscale patterned wafers
Institute of Scientific and Technical Information of China (English)
2010-01-01
Temperature nonuniformity in rapid thermal processing of wafers is a critical problem facing the semiconductor industry. One cause of the problem is the nonuniform absorption of thermal radiation in patterned wafers where the optical properties vary across the wafer surface. This paper presents a parametric study of the radiative properties of patterned wafers, considering the effect of temperature, wavelength, and polarization. The finite-difference time-domain (FDTD) method is employed to examine the effect of various trench sizes on the radiative properties via numerically solving the Maxwell equations. The effective medium theory (EMT) is also used to help explain the absorptance prediction. The results show that in the cases with trench size variation, the resonance cavity effect may increase the absorptance as the trench width increases. And in the cases with trench size increasing at several different filling ratios, the absorptance does not change much at small filling ratio. The effects of the resonant cavity, diffraction, wave interferences on the spectral-directional absorptance were also discussed. This work is of great importance for optimization of advanced annealing techniques in semiconductor manufacturing.
7. The influence of the solar radiation model on the calcutated solar radiation from a horizontal surface to a tilted surface
DEFF Research Database (Denmark)
Andersen, Elsa; Lund, Hans; Furbo, Simon
2004-01-01
in the calculation. The weather data are measured at the solar radiation measurement station, SMS at the Department of Civil Engineering at the Technical University of Denmark. In this study the weather data are combined with solar collector calculations based on solar collector test carried out at Solar Energy......Measured solar radiation data are most commonly available as total solar radiation on a horizontal surface. When using solar radiation measured on horizontal to calculate the solar radiation on tilted surfaces and thereby the thermal performance of different applications such as buildings and solar...... heating systems, different solar radiation models can be used. The calculation of beam radiation from a horizontal surface to a tilted surface can be done exactly whereas different solar radiation models can calculate the sky diffuse radiation. The sky diffuse radiation can either be assumed evenly...
8. Benchmarks and models for 1-D radiation transport in stochastic participating media
Energy Technology Data Exchange (ETDEWEB)
Miller, D S
2000-08-21
Benchmark calculations for radiation transport coupled to a material temperature equation in a 1-D slab and 1-D spherical geometry binary random media are presented. The mixing statistics are taken to be homogeneous Markov statistics in the 1-D slab but only approximately Markov statistics in the 1-D sphere. The material chunk sizes are described by Poisson distribution functions. The material opacities are first taken to be constant and then allowed to vary as a strong function of material temperature. Benchmark values and variances for time evolution of the ensemble average of material temperature energy density and radiation transmission are computed via a Monte Carlo type method. These benchmarks are used as a basis for comparison with three other approximate methods of solution. One of these approximate methods is simple atomic mix. The second approximate model is an adaptation of what is commonly called the Levermore-Pomraning model and which is referred to here as the standard model. It is shown that recasting the temperature coupling as a type of effective scattering can be useful in formulating the third approximate model, an adaptation of a model due to Su and Pomraning which attempts to account for the effects of scattering in a stochastic context. This last adaptation shows consistent improvement over both the atomic mix and standard models when used in the 1-D slab geometry but shows limited improvement in the 1-D spherical geometry. Benchmark values are also computed for radiation transmission from the 1-D sphere without material heating present. This is to evaluate the performance of the standard model on this geometry--something which has never been done before. All of the various tests demonstrate the importance of stochastic structure on the solution. Also demonstrated are the range of usefulness and limitations of a simple atomic mix formulation.
Science.gov (United States)
Davis, B. N.; LeVeque, R. J.
2016-12-01
One difficulty in developing numerical methods for tsunami modeling is the fact that solutions contain time-varying regions where much higher resolution is required than elsewhere in the domain, particularly when tracking a tsunami propagating across the ocean. The open source GeoClaw software deals with this issue by using block-structured adaptive mesh refinement to selectively refine around propagating waves. For problems where only a target area of the total solution is of interest (e.g., one coastal community), a method that allows identifying and refining the grid only in regions that influence this target area would significantly reduce the computational cost of finding a solution. In this work, we show that solving the time-dependent adjoint equation and using a suitable inner product with the forward solution allows more precise refinement of the relevant waves. We present the adjoint methodology first in one space dimension for illustration and in a broad context since it could also be used in other adaptive software, and potentially for other tsunami applications beyond adaptive refinement. We then show how this adjoint method has been integrated into the adaptive mesh refinement strategy of the open source GeoClaw software and present tsunami modeling results showing that the accuracy of the solution is maintained and the computational time required is significantly reduced through the integration of the adjoint method into adaptive mesh refinement.
10. Recent Developments in the Radiation Belt Environment Model
Science.gov (United States)
Fok, M.-C.; Glocer, A.; Zheng, Q.; Horne, R. B.; Meredith, N. P.; Albert, J. M.; Nagai, T.
2010-01-01
The fluxes of energetic particles in the radiation belts are found to be strongly controlled by the solar wind conditions. In order to understand and predict the radiation particle intensities, we have developed a physics-based Radiation Belt Environment (RBE) model that considers the influences from the solar wind, ring current and plasmasphere. Recently, an improved calculation of wave-particle interactions has been incorporated. In particular, the model now includes cross diffusion in energy and pitch-angle. We find that the exclusion of cross diffusion could cause significant overestimation of electron flux enhancement during storm recovery. The RBE model is also connected to MHD fields so that the response of the radiation belts to fast variations in the global magnetosphere can be studied.Weare able to reproduce the rapid flux increase during a substorm dipolarization on 4 September 2008. The timing is much shorter than the time scale of wave associated acceleration.
11. Adaptation of Predictive Models to PDA Hand-Held Devices
Directory of Open Access Journals (Sweden)
Lin, Edward J
2008-01-01
Full Text Available Prediction models using multiple logistic regression are appearing with increasing frequency in the medical literature. Problems associated with these models include the complexity of computations when applied in their pure form, and lack of availability at the bedside. Personal digital assistant (PDA hand-held devices equipped with spreadsheet software offer the clinician a readily available and easily applied means of applying predictive models at the bedside. The purposes of this article are to briefly review regression as a means of creating predictive models and to describe a method of choosing and adapting logistic regression models to emergency department (ED clinical practice.
12. A Model of Internal Communication in Adaptive Communication Systems.
Science.gov (United States)
Williams, M. Lee
A study identified and categorized different types of internal communication systems and developed an applied model of internal communication in adaptive organizational systems. Twenty-one large organizations were selected for their varied missions and diverse approaches to managing internal communication. Individual face-to-face or telephone…
13. Adapting the Transtheoretical Model of Change to the Bereavement Process
Science.gov (United States)
Calderwood, Kimberly A.
2011-01-01
Theorists currently believe that bereaved people undergo some transformation of self rather than returning to their original state. To advance our understanding of this process, this article presents an adaptation of Prochaska and DiClemente's transtheoretical model of change as it could be applied to the journey that bereaved individuals…
14. Modelling Adaptive Learning Behaviours for Consensus Formation in Human Societies
Science.gov (United States)
Yu, Chao; Tan, Guozhen; Lv, Hongtao; Wang, Zhen; Meng, Jun; Hao, Jianye; Ren, Fenghui
2016-06-01
Learning is an important capability of humans and plays a vital role in human society for forming beliefs and opinions. In this paper, we investigate how learning affects the dynamics of opinion formation in social networks. A novel learning model is proposed, in which agents can dynamically adapt their learning behaviours in order to facilitate the formation of consensus among them, and thus establish a consistent social norm in the whole population more efficiently. In the model, agents adapt their opinions through trail-and-error interactions with others. By exploiting historical interaction experience, a guiding opinion, which is considered to be the most successful opinion in the neighbourhood, can be generated based on the principle of evolutionary game theory. Then, depending on the consistency between its own opinion and the guiding opinion, a focal agent can realize whether its opinion complies with the social norm (i.e., the majority opinion that has been adopted) in the population, and adapt its behaviours accordingly. The highlight of the model lies in that it captures the essential features of people’s adaptive learning behaviours during the evolution and formation of opinions. Experimental results show that the proposed model can facilitate the formation of consensus among agents, and some critical factors such as size of opinion space and network topology can have significant influences on opinion dynamics.
15. A Context-Adaptive Model for Program Evaluation.
Science.gov (United States)
Lynch, Brian K.
1990-01-01
Presents an adaptable, context-sensitive model for ESL/EFL program evaluation, consisting of seven steps that guide an evaluator through consideration of relevant issues, information, and design elements. Examples from an evaluation of the Reading for Science and Technology Project at the University of Guadalajara, Mexico are given. (31…
16. Occultation Modeling for Radiation Obstruction Effects on Spacecraft Systems
Science.gov (United States)
de Carufel, Guy; Li, Zu Qun; Harvey, Jason; Crues, Edwin Z.; Bielski, Paul
2016-01-01
A geometric occultation model has been developed to determine line-of-sight obstruction of radiation sources expected for different NASA space exploration mission designs. Example applications includes fidelity improvements for surface lighting conditions, radiation pressure, thermal and power subsystem modeling. The model makes use of geometric two dimensional shape primitives to most effectively model space vehicles. A set of these primitives is used to represent three dimensional obstructing objects as a two dimensional outline from the perspective of an observing point of interest. Radiation sources, such as the Sun or a Moon's albedo is represented as a collection of points, each of which is assigned a flux value to represent a section of the radiation source. Planetary bodies, such as a Martian moon, is represented as a collection of triangular facets which are distributed in spherical height fields for optimization. These design aspects and the overall model architecture will be presented. Specific uses to be presented includes a study of the lighting condition on Phobos for a possible future surface mission, and computing the incident flux on a spacecraft's solar panels and radiators from direct and reflected solar radiation subject to self-shadowing or shadowing by third bodies.
17. Modeling Polarized Solar Radiation for Correction of Satellite Data
Science.gov (United States)
Sun, W.
2014-12-01
18. Simulation and modeling of solar radiation in Saudi Arabia
Energy Technology Data Exchange (ETDEWEB)
Zuhairy, A.A.; Sayigh, A.A.M. [Reading Univ. (United Kingdom). Dept. of Engineering
1995-04-01
A mathematical model is used to generate the hourly data for the total solar radiation on a horizontal surface. The generated data are based on the hourly recorded visibility data for 20 years (1970-1989). The model year technique was then applied to model the 20 years of hourly data of solar radiation into one statistically representative year. A model year of hourly data was then generated for the beam and diffuse components of solar radiation on a horizontal surface. Similarly, a model year of hourly data was also generated for the total solar radiation on tilted surfaces with different orientations with its beam, diffuse and reflected components. A simple methodology is proposed for calculating the solar radiation on vertical surfaces, based on a solar impact factor (SIF). Monthly means and daily totals of hourly sums for each month of the year are discussed. The hourly data of solar radiation for a typical day for each month of the year are presented. The data were generated for the four climatic zones of Saudi Arabia, the hot-dry (Riyadh), the warm-humid (Jeddah), the maritime inland desert climate (Dhahran) and the upland climate zone (Taif). The accuracy of the results is discussed and found to be above 90% representative. (author)
19. Improved Solar-Radiation-Pressure Models for GPS Satellites
Science.gov (United States)
Bar-Sever, Yoaz; Kuang, Da
2006-01-01
A report describes a series of computational models conceived as an improvement over prior models for determining effects of solar-radiation pressure on orbits of Global Positioning System (GPS) satellites. These models are based on fitting coefficients of Fourier functions of Sun-spacecraft- Earth angles to observed spacecraft orbital motions.
20. Mutagenic adaptive response to high-LET radiation in human lymphoblastoid cells exposed to low doses of heavy-ion radiation
Energy Technology Data Exchange (ETDEWEB)
Vares, Guillaume, E-mail: [email protected] [Radiation Risk Reduction Research Program, National Institute of Radiological Sciences, Anagawa 4-9-1, Inage-ku, Chiba 263-8555 (Japan); Wang, Bing, E-mail: [email protected] [Radiation Risk Reduction Research Program, National Institute of Radiological Sciences, Anagawa 4-9-1, Inage-ku, Chiba 263-8555 (Japan); Tanaka, Kaoru; Kakimoto, Ayana; Eguchi-Kasai, Kyomi; Nenoi, Mitsuru [Radiation Risk Reduction Research Program, National Institute of Radiological Sciences, Anagawa 4-9-1, Inage-ku, Chiba 263-8555 (Japan)
2011-07-01
Adaptive response (AR) and bystander effect are two important phenomena involved in biological responses to low doses of ionizing radiation (IR). Furthermore, there is a strong interest in better understanding the biological effects of high-LET radiation. We previously demonstrated the ability of low doses of X-rays to induce an AR to challenging heavy-ion radiation . In this study, we assessed in vitro the ability of priming low doses (0.01 Gy) of heavy-ion radiation to induce a similar AR to a subsequent challenging dose (1-4 Gy) of high-LET IR (carbon-ion: 20 and 40 keV/{mu}m, neon-ion: 150 keV/{mu}m) in TK6, AHH-1 and NH32 cells. Our results showed that low doses of high-LET radiation can induce an AR characterized by lower mutation frequencies at hypoxanthine-guanine phosphoribosyl transferase locus and faster DNA repair kinetics, in cells expressing p53.
1. Plasmonic-cavity model for radiating nano-rod antennas.
Science.gov (United States)
Peng, Liang; Mortensen, N Asger
2014-01-23
In this paper, we propose the analytical solution of nano-rod antennas utilizing a cylindrical harmonics expansion. By treating the metallic nano-rods as plasmonic cavities, we derive closed-form expressions for both the internal and the radiated fields, as well as the resonant condition and the radiation efficiency. With our theoretical model, we show that besides the plasmonic resonances, efficient radiation takes advantage of (a) rendering a large value of the rods' radius and (b) a central-fed profile, through which the radiation efficiency can reach up to 70% and even higher in a wide frequency band. Our theoretical expressions and conclusions are general and pave the way for engineering and further optimization of optical antenna systems and their radiation patterns.
2. A Simplified Scheme of the Generalized Layered Radiative Transfer Model
Institute of Scientific and Technical Information of China (English)
2007-01-01
3. Multiscale adaptive basis function modeling of spatiotemporal vectorcardiogram signals.
Science.gov (United States)
Gang Liu; Hui Yang
2013-03-01
Mathematical modeling of cardiac electrical signals facilitates the simulation of realistic cardiac electrical behaviors, the evaluation of algorithms, and the characterization of underlying space-time patterns. However, there are practical issues pertinent to model efficacy, robustness, and generality. This paper presents a multiscale adaptive basis function modeling approach to characterize not only temporal but also spatial behaviors of vectorcardiogram (VCG) signals. Model parameters are adaptively estimated by the "best matching" projections of VCG characteristic waves onto a dictionary of nonlinear basis functions. The model performance is experimentally evaluated with respect to the number of basis functions, different types of basis function (i.e., Gaussian, Mexican hat, customized wavelet, and Hermitian wavelets), and various cardiac conditions, including 80 healthy controls and different myocardial infarctions (i.e., 89 inferior, 77 anterior-septal, 56 inferior-lateral, 47 anterior, and 43 anterior-lateral). Multiway analysis of variance shows that the basis function and the model complexity have significant effects on model performances while cardiac conditions are not significant. The customized wavelet is found to be an optimal basis function for the modeling of spacetime VCG signals. The comparison of QT intervals shows small relative errors (model representations and realworld VCG signals when the model complexity is greater than 10. The proposed model shows great potentials to model space-time cardiac pathological behaviors and can lead to potential benefits in feature extraction, data compression, algorithm evaluation, and disease prognostics.
4. Modeling Hospitals’ Adaptive Capacity during a Loss of Infrastructure Services
Directory of Open Access Journals (Sweden)
Eric D. Vugrin
2015-01-01
Full Text Available Resilience in hospitals - their ability to withstand, adapt to, and rapidly recover from disruptive events - is vital to their role as part of national critical infrastructure. This paper presents a model to provide planning guidance to decision makers about how to make hospitals more resilient against possible disruption scenarios. This model represents a hospital’s adaptive capacities that are leveraged to care for patients during loss of infrastructure services (power, water, etc.. The model is an optimization that reallocates and substitutes resources to keep patients in a high care state or allocates resources to allow evacuation if necessary. An illustrative example demonstrates how the model might be used in practice.
5. On fractional order composite model reference adaptive control
Science.gov (United States)
Wei, Yiheng; Sun, Zhenyuan; Hu, Yangsheng; Wang, Yong
2016-08-01
This paper presents a novel composite model reference adaptive control approach for a class of fractional order linear systems with unknown constant parameters. The method is extended from the model reference adaptive control. The parameter estimation error of our method depends on both the tracking error and the prediction error, whereas the existing method only depends on the tracking error, which makes our method has better transient performance in the sense of generating smooth system output. By the aid of the continuous frequency distributed model, stability of the proposed approach is established in the Lyapunov sense. Furthermore, the convergence property of the model parameters estimation is presented, on the premise that the closed-loop control system is stable. Finally, numerical simulation examples are given to demonstrate the effectiveness of the proposed schemes.
6. An adaptive multi-feature segmentation model for infrared image
Science.gov (United States)
Zhang, Tingting; Han, Jin; Zhang, Yi; Bai, Lianfa
2016-04-01
Active contour models (ACM) have been extensively applied to image segmentation, conventional region-based active contour models only utilize global or local single feature information to minimize the energy functional to drive the contour evolution. Considering the limitations of original ACMs, an adaptive multi-feature segmentation model is proposed to handle infrared images with blurred boundaries and low contrast. In the proposed model, several essential local statistic features are introduced to construct a multi-feature signed pressure function (MFSPF). In addition, we draw upon the adaptive weight coefficient to modify the level set formulation, which is formed by integrating MFSPF with local statistic features and signed pressure function with global information. Experimental results demonstrate that the proposed method can make up for the inadequacy of the original method and get desirable results in segmenting infrared images.
7. Radiative and non-radiative recombinations in tensile strained Ge microstrips: Photoluminescence experiments and modeling
Energy Technology Data Exchange (ETDEWEB)
Virgilio, M., E-mail: [email protected] [Dip. di Fisica “E. Fermi,” Università di Pisa, Largo Pontecorvo 3, 56127 Pisa (Italy); NEST, Istituto Nanoscienze-CNR, P.za San Silvestro 12, 56127 Pisa (Italy); Schroeder, T.; Yamamoto, Y. [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany); Capellini, G. [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany); Dip. di scienze, Università Roma Tre, viale G. Marconi 446, 00146 Roma (Italy)
2015-12-21
Tensile germanium microstrips are candidate as gain material in Si-based light emitting devices due to the beneficial effect of the strain field on the radiative recombination rate. In this work, we thoroughly investigate their radiative recombination spectra by means of micro-photoluminescence experiments at different temperatures and excitation powers carried out on samples featuring different tensile strain values. For sake of comparison, bulk Ge(001) photoluminescence is also discussed. The experimental findings are interpreted in light of a numerical modeling based on a multi-valley effective mass approach, taking in to account the depth dependence of the photo-induced carrier density and of the self-absorption effect. The theoretical modeling allowed us to quantitatively describe the observed increase of the photoluminescence intensity for increasing values of strain, excitation power, and temperature. The temperature dependence of the non-radiative recombination time in this material has been inferred thanks to the model calibration procedure.
8. Adaptive quasi-likelihood estimate in generalized linear models
Institute of Scientific and Technical Information of China (English)
CHEN Xia; CHEN Xiru
2005-01-01
This paper gives a thorough theoretical treatment on the adaptive quasilikelihood estimate of the parameters in the generalized linear models. The unknown covariance matrix of the response variable is estimated by the sample. It is shown that the adaptive estimator defined in this paper is asymptotically most efficient in the sense that it is asymptotic normal, and the covariance matrix of the limit distribution coincides with the one for the quasi-likelihood estimator for the case that the covariance matrix of the response variable is completely known.
9. Supply Chain as Complex Adaptive System and Its Modeling
Institute of Scientific and Technical Information of China (English)
MingmingWang
2004-01-01
Supply chain is a complex, hierarchical, integrated, open and dynamic network.Every node in the network is an independent business unit that unites other organizations to develop its value, the competition and cooperation between these units are basic impetus of the development and evolution of the supply chain system. The characteristics of supply chain as a complex adaptive system and its modeling are discussed in this paper, and use an example demonstrating the feasibility of CAS modeling in supply chain management study.
10. Adaptive Regression and Classification Models with Applications in Insurance
Directory of Open Access Journals (Sweden)
Jekabsons Gints
2014-07-01
Full Text Available Nowadays, in the insurance industry the use of predictive modeling by means of regression and classification techniques is becoming increasingly important and popular. The success of an insurance company largely depends on the ability to perform such tasks as credibility estimation, determination of insurance premiums, estimation of probability of claim, detecting insurance fraud, managing insurance risk. This paper discusses regression and classification modeling for such types of prediction problems using the method of Adaptive Basis Function Construction
11. Fast Adaptation in Generative Models with Generative Matching Networks
OpenAIRE
Bartunov, Sergey; Vetrov, Dmitry P.
2016-01-01
Despite recent advances, the remaining bottlenecks in deep generative models are necessity of extensive training and difficulties with generalization from small number of training examples. Both problems may be addressed by conditional generative models that are trained to adapt the generative distribution to additional input data. So far this idea was explored only under certain limitations such as restricting the input data to be a single object or multiple objects representing the same con...
12. Low-Dose Ionizing Radiation Affects Mesenchymal Stem Cells via Extracellular Oxidized Cell-Free DNA: A Possible Mediator of Bystander Effect and Adaptive Response
Directory of Open Access Journals (Sweden)
V. A. Sergeeva
2017-01-01
Full Text Available We have hypothesized that the adaptive response to low doses of ionizing radiation (IR is mediated by oxidized cell-free DNA (cfDNA fragments. Here, we summarize our experimental evidence for this model. Studies involving measurements of ROS, expression of the NOX (superoxide radical production, induction of apoptosis and DNA double-strand breaks, antiapoptotic gene expression and cell cycle inhibition confirm this hypothesis. We have demonstrated that treatment of mesenchymal stem cells (MSCs with low doses of IR (10 cGy leads to cell death of part of cell population and release of oxidized cfDNA. cfDNA has the ability to penetrate into the cytoplasm of other cells. Oxidized cfDNA, like low doses of IR, induces oxidative stress, ROS production, ROS-induced oxidative modifications of nuclear DNA, DNA breaks, arrest of the cell cycle, activation of DNA reparation and antioxidant response, and inhibition of apoptosis. The MSCs pretreated with low dose of irradiation or oxidized cfDNA were equally effective in induction of adaptive response to challenge further dose of radiation. Our studies suggest that oxidized cfDNA is a signaling molecule in the stress signaling that mediates radiation-induced bystander effects and that it is an important component of the development of radioadaptive responses to low doses of IR.
13. Prediction of relativistic electron flux in the Earth's outer radiation belt at geostationary orbit by adaptive methods
Science.gov (United States)
Myagkova, I. N.; Dolenko, S. A.; Efitorov, A. O.; Shirokii, V. R.; Sentemova, N. S.
2017-01-01
The paper investigates the possibilities of the prediction of the time series of the flux of relativistic electrons in the Earth's outer radiation belt by parameters of the solar wind and the interplanetary magnetic field measured at the libration point and by the values of the geomagnetic indices. Different adaptive methods are used (namely, artificial neural networks, group method of data handling, and projection to latent structures). The comparison of quality indicators of predictions with a horizon of 1-12 h between each other and with the trivial model prediction has shown that the best result is obtained for the average value of the responses of three neural networks that have been trained with different sets of initial weights. The prediction result of the group method of data handling is close to the result of neural networks, and the projection to latent structures is much worse. It is shown that an increase in the prediction horizon from 1 to 12 h reduces its quality but not dramatically, which makes it possible to use these methods for medium-term prediction.
14. Free-streaming radiation in cosmological models with spatial curvature
Science.gov (United States)
Wilson, M. L.
1982-01-01
The effects of spatial curvature on radiation anisotropy are examined for the standard Friedmann-Robertson-Walker model universes. The effect of curvature is found to be very important when considering fluctuations with wavelengths comparable to the horizon. It is concluded that the behavior of radiation fluctuations in models with spatial curvature is quite different from that in spatially flat models, and that models with negative curvature are most strikingly different. It is therefore necessary to take the curvature into account in careful studies of the anisotropy of the microwave background.
15. Dosimetric and radiobiological consequences of computed tomography-guided adaptive strategies for intensity modulated radiation therapy of the prostate.
Science.gov (United States)
Battista, Jerry J; Johnson, Carol; Turnbull, David; Kempe, Jeff; Bzdusek, Karl; Van Dyk, Jacob; Bauman, Glenn
2013-12-01
16. Extensions in adaptive model tracking with mitigated passivity conditions
Institute of Scientific and Technical Information of China (English)
Itzhak BARKANA
2013-01-01
Feasibility of nonlinear and adaptive control methodologies in multivariable linear timeinvariant systems with state space realization {A,B,C} has apparently been limited by the standard strict passivity (or positive realness) conditions that imply that the product CB must be positive definite symmetric.More recently the symmetry condition has been mitigated,requiring instead that the not necessarily symmetric matrix CB be diagonalizable and with positive real eigenvalues.However,although the mitigated conditions are useful in proving pure stabilizability with Adaptive Controllers,the Model Tracking question has remained open and counterexamples seem to demonstrate total divergence of standard model reference adaptive controllers when the regular passivity conditions are not fully satisfied.Therefore,this paper further extends the previous results,showing that the new passivity conditions do guarantee stability with adaptive model tracking.Examples show how the new conditions solve the case of flexible structures with unknown parameters when perfect collocation is not possible.Also,the so-called counterexamples become simple,well-behaved,examples.
17. Lineage diversity and size disparity in Musteloidea: testing patterns of adaptive radiation using molecular and fossil-based methods.
Science.gov (United States)
Law, Chris J; Slater, Graham J; Mehta, Rita S
2017-05-04
18. OMEGA: The operational multiscale environment model with grid adaptivity
Energy Technology Data Exchange (ETDEWEB)
Bacon, D.P.
1995-07-01
This review talk describes the OMEGA code, used for weather simulation and the modeling of aerosol transport through the atmosphere. Omega employs a 3D mesh of wedge shaped elements (triangles when viewed from above) that adapt with time. Because wedges are laid out in layers of triangular elements, the scheme can utilize structured storage and differencing techniques along the elevation coordinate, and is thus a hybrid of structured and unstructured methods. The utility of adaptive gridding in this moded, near geographic features such as coastlines, where material properties change discontinuously, is illustrated. Temporal adaptivity was used additionally to track moving internal fronts, such as clouds of aerosol contaminants. The author also discusses limitations specific to this problem, including manipulation of huge data bases and fixed turn-around times. In practice, the latter requires a carefully tuned optimization between accuracy and computation speed.
19. Nonhydrostatic adaptive mesh dynamics for multiscale climate models (Invited)
Science.gov (United States)
Collins, W.; Johansen, H.; McCorquodale, P.; Colella, P.; Ullrich, P. A.
2013-12-01
Many of the atmospheric phenomena with the greatest potential impact in future warmer climates are inherently multiscale. Such meteorological systems include hurricanes and tropical cyclones, atmospheric rivers, and other types of hydrometeorological extremes. These phenomena are challenging to simulate in conventional climate models due to the relatively coarse uniform model resolutions relative to the native nonhydrostatic scales of the phenomonological dynamics. To enable studies of these systems with sufficient local resolution for the multiscale dynamics yet with sufficient speed for climate-change studies, we have adapted existing adaptive mesh dynamics for the DOE-NSF Community Atmosphere Model (CAM). In this talk, we present an adaptive, conservative finite volume approach for moist non-hydrostatic atmospheric dynamics. The approach is based on the compressible Euler equations on 3D thin spherical shells, where the radial direction is treated implicitly (using a fourth-order Runga-Kutta IMEX scheme) to eliminate time step constraints from vertical acoustic waves. Refinement is performed only in the horizontal directions. The spatial discretization is the equiangular cubed-sphere mapping, with a fourth-order accurate discretization to compute flux averages on faces. By using both space-and time-adaptive mesh refinement, the solver allocates computational effort only where greater accuracy is needed. The resulting method is demonstrated to be fourth-order accurate for model problems, and robust at solution discontinuities and stable for large aspect ratios. We present comparisons using a simplified physics package for dycore comparisons of moist physics. Hadley cell lifting an advected tracer into upper atmosphere, with horizontal adaptivity
20. Measurement and Modeling of Particle Radiation in Coal Flames
DEFF Research Database (Denmark)
Bäckström, Daniel; Johansson, Robert; Andersson, Klas Jerker
2014-01-01
This work aims at developing a methodology that can provide information of in-flame particle radiation in industrial-scale flames. The method is based on a combination of experimental and modeling work. The experiments have been performed in the high-temperature zone of a 77 kWth swirling lignite...... properties. The in-flame particle radiation was measured with a Fourier transform infrared (FTIR) spectrometer connected to a water-cooled probe via fiber optics. In the cross-section of the flame investigated, the particles were found to be the dominating source of radiation. Apart from giving information...
1. A Prediction Model of MF Radiation in Environmental Assessment
Institute of Scientific and Technical Information of China (English)
HE-SHAN GE; YAN-FENG HONG
2006-01-01
Objective To predict the impact of MF radiation on human health.Methods The vertical distribution of field intensity was estimated by analogism on the basis of measured values from simulation measurement. Results A kind of analogism on the basis of geometric proportion decay pattern is put forward in the essay. It showed that with increasing of height the field intensity increased according to geometric proportion law. Conclusion This geometric proportion prediction model can be used to estimate the impact of MF radiation on inhabited environment, and can act as a reference pattern in predicting the environmental impact level of MF radiation.
2. How near, how far? Adaptive radiation in mammals and birds on various islands
NARCIS (Netherlands)
Hoek Ostende, van den L.W.; Locatelli, E.; Meijer, H.J.M.
2011-01-01
Many factors control radiations on islands, but some general patterns do emerge. Bird radiations are mostly found on oceanic archipelagos far from the continental coast line. Mammal radiations are mostly know from island arcs, which are somewhat easier to reach though still isolated enough to allow
3. How near, how far? Adaptive radiation in mammals and birds on various islands
NARCIS (Netherlands)
Hoek Ostende, van den L.W.; Locatelli, E.; Meijer, H.J.M.
2011-01-01
Many factors control radiations on islands, but some general patterns do emerge. Bird radiations are mostly found on oceanic archipelagos far from the continental coast line. Mammal radiations are mostly know from island arcs, which are somewhat easier to reach though still isolated enough to allow
4. A Model for Hourly Solar Radiation Data Generation from Daily Solar Radiation Data Using a Generalized Regression Artificial Neural Network
Directory of Open Access Journals (Sweden)
Tamer Khatib
2015-01-01
Full Text Available This paper presents a model for predicting hourly solar radiation data using daily solar radiation averages. The proposed model is a generalized regression artificial neural network. This model has three inputs, namely, mean daily solar radiation, hour angle, and sunset hour angle. The output layer has one node which is mean hourly solar radiation. The training and development of the proposed model are done using MATLAB and 43800 records of hourly global solar radiation. The results show that the proposed model has better prediction accuracy compared to some empirical and statistical models. Two error statistics are used in this research to evaluate the proposed model, namely, mean absolute percentage error and root mean square error. These values for the proposed model are 11.8% and −3.1%, respectively. Finally, the proposed model shows better ability in overcoming the sophistic nature of the solar radiation data.
5. Megaphylogeny, cell body plans, adaptive zones: causes and timing of eukaryote basal radiations.
Science.gov (United States)
Cavalier-Smith, Thomas
2009-01-01
I discuss eukaryote megaphylogeny and the timing of major innovations in the light of multigene trees and the rarity of marine/freshwater evolutionary transitions. The first eukaryotes were aerobic phagotrophs, probably substratum-associated heterotrophic amoeboflagellates. The primary eukaryote bifurcation generated unikonts (ancestrally probably unicentriolar, with a conical microtubular [MT] cytoskeleton) and bikonts (ciliary transformation from anterior cilium to ancestrally gliding posterior cilium; cytoskeleton of ventral MT bands). Unikonts diverged into Amoebozoa with anterior cilia, lost when lobosan broad pseudopods evolved for locomotion, and Choanozoa with posterior cilium and filose pseudopods that became unbranched tentacles/microvilli in holozoa and eventually the choanoflagellate/choanocyte collar. Of choanozoan ancestry, animals evolved epithelia, fibroblasts, eggs, and sperm. Fungi and Ichthyosporea evolved walls. Bikonts, ancestrally with ventral grooves, include three adaptively divergent megagroups: Rhizaria (Retaria and Cercozoa, ancestrally reticulofilose soft-surfaced gliding amoeboflagellates), and the originally planktonic Excavata, and the corticates (Plantae and chromalveolates) that suppressed pseudopodia. Excavata evolved cilia-generated feeding currents for grooval ingestion; corticates evolved cortical alveoli and ciliary hairs. Symbiogenetic origin and transfers of chloroplasts stimulated an explosive radiation of corticates--hard to resolve on multigene trees--and opisthokonts, and ensuing Cambrian explosions of animals and protists. Plantae lost phagotrophy and multiply evolved walls and macroalgae. Apusozoa, with dorsal pellicle and ventral pseudopods, are probably the most divergent bikonts or related to opisthokonts. Eukaryotes probably originated 800-850 My ago. Amoebozoa, Apusozoa, Loukozoa, and Metamonada may be the only extant eukaryote phyla pre-dating Neoproterozoic snowball earth. New subphyla are established for
Directory of Open Access Journals (Sweden)
Full Text Available A macrogenomic investigation of a Holarctic clade of black flies-the Simulium cholodkovskii lineage-provided a platform to explore the implications of a unique, synapomorphic whole-arm interchange in the evolution of black flies. Nearly 60 structural rearrangements were discovered in the polytene complement of the lineage, including 15 common to all 138 analyzed individuals, relative to the central sequence for the entire subgenus Simulium. Three species were represented, of which two Palearctic entities (Simulium cholodkovskii and S. decimatum were sympatric; an absence of hybrids confirmed their reproductive isolation. A third (Nearctic entity had nonhomologous sex chromosomes, relative to the other species, and is considered a separate species, for which the name Simulium nigricoxum is revalidated. A cytophylogeny is inferred and indicates that the two Palearctic taxa are sister species and these, in turn, are the sister group of the Nearctic species. The rise of the S. cholodkovskii lineage encompassed complex chromosomal and genomic restructuring phenomena associated with speciation in black flies, viz. expression of one and the same rearrangement as polymorphic, fixed, or sex linked in different species; taxon-specific differentiation of sex chromosomes; and reciprocal translocation of chromosome arms. The translocation is hypothesized to have occurred early in male spermatogonia, with the translocated chromosomal complement being transmitted to the X- and Y-bearing sperm during spermatogenesis, resulting in alternate disjunction of viable F1 translocation heterozygotes and the eventual formation of more viable and selectable F2 translocation homozygous progeny. Of 11 or 12 independently derived whole-arm interchanges known in the family Simuliidae, at least six are associated with subsequent speciation events, suggesting a facilitating role of translocations in adaptive radiations. The findings are discussed in the context of potential
7. Career Development and Older Workers: Study Evaluating Adaptability in Older Workers Using Hall's Model
Science.gov (United States)
Strate, Merwyn L.; Torraco, Richard J.
2005-01-01
This qualitative case study described the development of adaptive competence in older workers using a Model of Adaptability and Adaptation developed by Dr. Douglas T. Hall (2002). Few studies have focused on the development of adaptability in workers when faced with change and no studies have focused on the development of adaptability in older…
8. Molecular mechanisms of low dose ionizing radiation-induced hormesis, adaptive responses, radioresistance, bystander effects, and genomic instability.
Science.gov (United States)
Tang, Feng Ru; Loke, Weng Keong
2015-01-01
To review research progress on the molecular mechanisms of low dose ionizing radiation (LDIR)-induced hormesis, adaptive responses, radioresistance, bystander effects, and genomic instability in order to provide clues for therapeutic approaches to enhance biopositive effects (defined as radiation-induced beneficial effects to the organism), and control bionegative effects (defined as radiation-induced harmful effects to the organism) and related human diseases. Experimental studies have indicated that Ataxia telangiectasia-mutated (ATM), extracellular signal-related kinase (ERK), mitogen-activated protein kinase (MAPK), phospho-c-Jun NH(2)-terminal kinase (JNK) and protein 53 (P53)-related signal transduction pathways may be involved in LDIR-induced hormesis; MAPK, P53 may be important for adaptive response; ATM, cyclooxygenase-2 (COX-2), ERK, JNK, reactive oxygen species (ROS), P53 for radioresistance; COX-2, ERK, MAPK, ROS, tumor necrosis factor receptor alpha (TNFα) for LDIR-induced bystander effect; whereas ATM, ERK, MAPK, P53, ROS, TNFα-related signal transduction pathways are involved in LDIR-induced genomic instability. These results suggest that different manifestations of LDIR-induced cellular responses may have different signal transduction pathways. On the other hand, LDIR-induced different responses may also share the same signal transduction pathways. For instance, P53 has been involved in LDIR-induced hormesis, adaptive response, radioresistance and genomic instability. Current data therefore suggest that caution should be taken when designing therapeutic approaches using LDIR to induce beneficial effects in humans.
9. A ROBUST ADAPTIVE VIDEO ENCODER BASED ON HUMAN VISUAL MODEL
Institute of Scientific and Technical Information of China (English)
Yin Hao; Zhang Jiangshan; Zhu Yaoting; Zhu Guangxi
2003-01-01
A Robust Adaptive Video Encoder (RAVE) based on human visual model is proposed. The encoder combines the best features of Fine Granularity Scalable (FGS) coding, framedropping coding, video redundancy coding, and human visual model. According to packet loss and available bandwidth of the network, the encoder adjust the output bit rate by jointly adapting quantization step-size instructed by human visual model, rate shaping, and periodically inserting key frame. The proposed encoder is implemented based on MPEG-4 encoder and is compared with the case of a conventional FGS algorithm. It is shown that RAVE is a very efficient robust video encoder that provides improved visual quality for the receiver and consumes equal or less network resource. Results are confirmed by subjective tests and simulation tests.
10. A ROBUST ADAPTIVE VIDEO ENCODER BASED ON HUMAN VISUAL MODEL
Institute of Scientific and Technical Information of China (English)
YinHao; ZhangJiangshan
2003-01-01
A Robust Adaptive Video Encoder (RAVE) based on human visual model is proposed.The encoder combines the best features of Fine Granularity Scalabla (FGS) coding,frame-dropping coding,video redundancy coding,and human visual model.According to packet loss and available bandwidth of the network,the encoder adjust the output bit rate by jointly adapting quantization step-size instructed by human visual model,rate shaping,and periodically inserting key frame.The proposed encoder is implemented based on MPEG-4 encoder and is compared with the case of a conventional FGS algorithm.It is shown that RAVE is a very efficient robust videl encoder that provides improved visual quality for the receiver and consumes equal or less network resource.Results are confirmed by subjective tests and simulation tests.
11. A model of psychological adaptation to migration and resettlement.
Science.gov (United States)
Aroian, K J
1990-01-01
The purpose of this qualitative study was to investigate the implications of migration for emotional status over time. Analysis of interview data provided by 25 Polish immigrants, who resided in the United States ranging from 4 months to 39 years, allowed the construction of a model describing migrants' psychological adaptation. Loss and disruption, novelty, occupational adjustment, language accommodation, and subordination were described as predominant aspects of migration and resettlement. Psychological adaptation required the dual task of resolving grief over losses and disruption involved with leaving Poland and of mastering resettlement conditions associated with novelty, occupation, language, and subordination. The model provides assessment parameters and direction for intervening with migrants who are distressed. The model may also be generalized to other types of life change as well.
12. Adaptive modeling of shallow fully nonlinear gravity waves
CERN Document Server
Dutykh, Denys; Mitsotakis, Dimitrios
2014-01-01
This paper presents an extended version of the celebrated Serre-Green-Naghdi (SGN) system. This extension is based on the well-known Bona-Smith-Nwogu trick which aims to improve the linear dispersion properties. We show that in the fully nonlinear setting it results in modifying the vertical acceleration. Even if this technique is well-known, the effect of this modification on the nonlinear properties of the model is not clear. The first goal of this study is to shed some light on the properties of solitary waves, as the most important class of nonlinear permanent solutions. Then, we propose a simple adaptive strategy to choose the optimal value of the free parameter at every instance of time. This strategy is validated by comparing the model prediction with the reference solutions of the full Euler equations and its classical counterpart. Numerical simulations show that the new adaptive model provides a much better accuracy for the same computational complexity.
13. Combined Injury Modeling: Radiation and Burn Workshop Report
Science.gov (United States)
2010-10-01
when radiation exposure is combined with burn. For instance, in the Chernobyl accident, hepatic encephalopathy was a major cause of death in patients...for radiation injury that block apoptosis and have demonstrated increased survival in animal models (Whitnall and Pellmar 2007). Cell loss also... Animal studies are needed to resolve this information gap. However, Institutional Animal Care and Use Committee (IACUC) approval for these types
14. Simulations of recoiling black holes: adaptive mesh refinement and radiative transfer
CERN Document Server
Meliani, Zakaria; Olivares, Hector; Porth, Oliver; Rezzolla, Luciano; Younsi, Ziri
2016-01-01
(Abridged) We here continue our effort to model the behaviour of matter when orbiting or accreting onto a generic black hole by developing a new numerical code employing advanced techniques geared solve the equations of in general-relativistic hydrodynamics. The new code employs a number of high-resolution shock-capturing Riemann-solvers and reconstruction algorithms, exploiting the enhanced accuracy and the reduced computational cost of AMR techniques. In addition, the code makes use of sophisticated ray-tracing libraries that, coupled with general-relativistic radiation-transfer calculations, allow us to compute accurately the electromagnetic emissions from such accretion flows. We validate the new code by presenting an extensive series of stationary accretion flows either in spherical or axial symmetry and performed either in 2D or 3D. In addition, we consider the highly nonlinear scenario of a recoiling black hole produced in the merger of a supermassive black hole binary interacting with the surrounding ...
15. Collisional-radiative modelling for the spectroscopic diagnostic of turbulent plasmas
Energy Technology Data Exchange (ETDEWEB)
Rosato, J.; Lefevre, T.; Escarguel, A.; Capes, H.; Catoire, F.; Marandet, Y.; Stamm, R. [PIIM, Universite de Provence, CNRS, Marseille (France); Rosmej, F.B. [Universite Pierre et Marie Curie, Paris (France)] [LULI, Palaiseau (France); Kadomtsev, M.B.; Levashova, M.G.; Lisitsa, V.S. [NFI, Russian Research Center, Kurchatov Institute, Moscow (Russian Federation); Bonhomme, G. [IJL, Universite de Nancy, CNRS, Vandoeuvre-les-Nancy (France)
2011-07-01
Spectroscopy is a diagnostic method widely used in plasma physics research, e.g. in laboratory experiments, in fusion devices or in astrophysics. Information on the plasma parameters (electron density, temperature etc.) can be obtained from the analysis of both line shapes and intensities through the use of suitable models. The aim of the present paper is to assess the role of turbulent fluctuations on line intensity ratios in the case of weakly radiating plasmas. This involves the use of collisional-radiative modelling. In the present work we address the radiation due to atomic lines in turbulent helium plasmas at low density/temperature. The statistical formalism previously used in line shape modelling is adapted in this way, and the atomic populations are calculated with a collisional-radiative code. Different regimes, according to the turbulence correlation time, have been considered. In the static case, which corresponds to low-frequency fluctuations, it has been shown that the turbulence can lead to an increase of the line intensities. An application to helium in realistic experimental conditions has revealed that line ratios are sensitive to the fluctuations, which offers a track to a diagnostic. In the dynamic case, the use of a reduced model in the case of an ideal two-level atom has revealed the possibility for a significant dependence of the atomic populations on the turbulence frequency
16. Final Report - Epigenetics of low dose radiation effects in an animal model
Energy Technology Data Exchange (ETDEWEB)
Kovalchuk, Olga
2014-10-22
17. High levels of interspecific gene flow in an endemic cichlid fish adaptive radiation from an extreme lake environment.
Science.gov (United States)
Ford, Antonia G P; Dasmahapatra, Kanchon K; Rüber, Lukas; Gharbi, Karim; Cezard, Timothee; Day, Julia J
2015-07-01
Studying recent adaptive radiations in isolated insular systems avoids complicating causal events and thus may offer clearer insight into mechanisms generating biological diversity. Here, we investigate evolutionary relationships and genomic differentiation within the recent radiation of Alcolapia cichlid fish that exhibit extensive phenotypic diversification, and which are confined to the extreme soda lakes Magadi and Natron in East Africa. We generated an extensive RAD data set of 96 individuals from multiple sampling sites and found evidence for genetic admixture between species within Lake Natron, with the highest levels of admixture between sympatric populations of the most recently diverged species. Despite considerable environmental separation, populations within Lake Natron do not exhibit isolation by distance, indicating panmixia within the lake, although individuals within lineages clustered by population in phylogenomic analysis. Our results indicate exceptionally low genetic differentiation across the radiation despite considerable phenotypic trophic variation, supporting previous findings from smaller data sets; however, with the increased power of densely sampled SNPs, we identify genomic peaks of differentiation (FST outliers) between Alcolapia species. While evidence of ongoing gene flow and interspecies hybridization in certain populations suggests that Alcolapia species are incompletely reproductively isolated, the identification of outlier SNPs under diversifying selection indicates the radiation is undergoing adaptive divergence.
18. Chromosome aberrations as biomarkers of radiation exposure: Modelling basic mechanisms
Science.gov (United States)
Ballarini, F.; Ottolenghi, A.
The space radiation environment is a mixed field consisting of different particles having different energies, including high charge and energy (HZE) ions. Conventional measurements of absorbed doses may not be sufficient to completely characterise the radiation field and perform reliable estimates of health risks. Biological dosimetry, based on the observation of specific radiation-induced endpoints (typically chromosome aberrations), can be a helpful approach in case of monitored exposure to space radiation or other mixed fields, as well as in case of accidental exposure. Furthermore, various ratios of aberrations (e.g. dicentric chromosomes to centric rings and complex exchanges to simple exchanges) have been suggested as possible fingerprints of radiation quality, although all of them have been subjected to some criticisms. In this context a mechanistic model and a Monte Carlo code for the simulation of chromosome aberration induction were developed. The model, able to provide dose-responses for different aberrations (e.g. dicentrics, rings, fragments, translocations, insertions and other complex exchanges), was further developed to assess the dependence of various ratios of aberrations on radiation quality. The predictions of the model were compared with available data, whose experimental conditions were faithfully reproduced. Particular attention was devoted to the scoring criteria adopted in different laboratories and to possible biases introduced by interphase death and mitotic delay. This latter aspect was investigated by taking into account both metaphase data and data obtained with Premature Chromosome Condensation (PCC).
19. A model of adaptive population migration in South Africa.
Science.gov (United States)
Hattingh, P S
1989-06-01
In South Africa, political factors, as well as socioeconomic forces have traditionally shaped the distribution pattern of the population. Economic and political realities have recently brought adaptive changes in government policy with concomitant migration responses. On explaining the model, the author describes 3 recent movements. 2 stem from policy changes as reflected in the national and urban distributional patterns of blacks, and the movement of Indians to the Orange Free State. The 3rd deals with the movement of elderly whites in the city of Pretoria. In the case of the blacks, migration into the white area has been a spontaneous evolutionary adaptation to the presence of strong push factors in the homelands and pull factors in the white area. Since 1910, governments have tried to restrict the influx of blacks by formulating and implementing normative policies of intervention, and since the 1960s, by actively promoting urban development in the homelands. Despite these measures, the numbers of blacks in the white area has swelled to such an extent that the government has adapted by increasing the rights of blacks. Blacks, Asians, and coloreds have also filtered into exclusive, white suburbs, ignoring government legislation. Currently, the government is reacting adaptively by proposing to create free settlement areas, but also normatively by placing more emphasis on areas reserved for specific racial groups. The 2nd example shows that despite efforts by Indians to move into the Orange Free State, progress is very slow. However, the process for adaptive migration to and within the Orange Free State has been set in motion. The 3rd example, that of elderly whites in Pretoria, reflects the migratory behavior of this group in response to the natural process of aging. Here there are no normative policies, but the authorities will probably formulate adaptive policies as the white South African population ages rapidly. Both normative and adaptive government policies
20. Planetary and Interplanetary Environmental Models for Radiation Analysis
Science.gov (United States)
DeAngelis, G.; Cucinotta, F. A.
2005-01-01
The essence of environmental modeling is presented as suited for radiation analysis purposes. The variables of fundamental importance for radiation environmental assessment are discussed. The characterization is performed by dividing modeling into three areas, namely the interplanetary medium, the circumplanetary environment, and the planetary or satellite surface. In the first area, the galactic cosmic rays (GCR) and their modulation by the heliospheric magnetic field as well as and solar particle events (SPE) are considered, in the second area the magnetospheres are taken into account, and in the third area the effect of the planetary environment is also considered. Planetary surfaces and atmospheres are modeled based on results from the most recent targeted spacecraft. The results are coupled with suited visualization techniques and radiation transport models in support of trade studies of health risks for future exploration missions.
1. Accuracy tests of radiation schemes used in hot Jupiter global circulation models
Science.gov (United States)
Amundsen, David S.; Baraffe, Isabelle; Tremblin, Pascal; Manners, James; Hayek, Wolfgang; Mayne, Nathan J.; Acreman, David M.
2014-04-01
The treatment of radiation transport in global circulation models (GCMs) is crucial for correctly describing Earth and exoplanet atmospheric dynamics processes. The two-stream approximation and correlated-k method are currently state-of-the-art approximations applied in both Earth and hot Jupiter GCM radiation schemes to facilitate the rapid calculation of fluxes and heating rates. Their accuracy have been tested extensively for Earth-like conditions, but verification of the methods' applicability to hot Jupiter-like conditions is lacking in the literature. We are adapting the UK Met Office GCM, the Unified Model (UM), for the study of hot Jupiters, and present in this work the adaptation of the Edwards-Slingo radiation scheme based on the two-stream approximation and the correlated-k method. We discuss the calculation of absorption coefficients from high-temperature line lists and highlight the large uncertainty in the pressure-broadened line widths. We compare fluxes and heating rates obtained with our adapted scheme to more accurate discrete ordinate (DO) line-by-line (LbL) calculations ignoring scattering effects. We find that, in most cases, errors stay below 10% for both heating rates and fluxes using ~10 k-coefficients in each band and a diffusivity factor D = 1.66. The two-stream approximation and the correlated-k method both contribute non-negligibly to the total error. We also find that using band-averaged absorption coefficients, which have previously been used in radiative-hydrodynamical simulations of a hot Jupiter, may yield errors of ~100%, and should thus be used with caution.
2. The response of mouse embryonic stem cells to low doses of γ-radiation: evidence for an adaptive response.
Science.gov (United States)
Kalantari, Hamid; Motamed, Nasrin; Mohseni Meybodi, Anahita; Jabbari Arfaie, Ali; Baharvand, Hossein; Gourabi, Hamid
2014-02-01
Low doses of ionizing radiation may induce an adaptive mechanism which protects embryonic stem cells against higher doses, a phenomenon which was reported previously for somatic cells. In this study, a possible adaptive response (AR) was evaluated by measuring cell survival (MTT assay) and chromosomal aberrations (micronucleus assay). Thymidine-synchronized mouse embryonic stem cells (mESCs) were exposed to 2.5, 3.7, or 5cGy (60)Co γ-rays and, after 5h challenged by a dose of 150cGy. mESCs pre-irradiated at 2.5cGy showed an adaptive response. Copyright © 2014 Elsevier B.V. All rights reserved.
3. MCNP model for the many KE-Basin radiation sources
Energy Technology Data Exchange (ETDEWEB)
Rittmann, P.D.
1997-05-21
This document presents a model for the location and strength of radiation sources in the accessible areas of KE-Basin which agrees well with data taken on a regular grid in September of 1996. This modelling work was requested to support dose rate reduction efforts in KE-Basin. Anticipated fuel removal activities require lower dose rates to minimize annual dose to workers. With this model, the effects of component cleanup or removal can be estimated in advance to evaluate their effectiveness. In addition, the sources contributing most to the radiation fields in a given location can be identified and dealt with.
4. Different radiation impedance models for finite porous materials
DEFF Research Database (Denmark)
Nolan, Melanie; Jeong, Cheol-Ho; Brunskog, Jonas;
2015-01-01
coupled to the transfer matrix method (TMM). These methods are found to yield comparable results when predicting the Sabine absorption coefficients of finite porous materials. Discrepancies with measurement results can essentially be explained by the unbalance between grazing and non-grazing sound field...... the infinite case. Thus, in order to predict the Sabine absorption coefficients of finite porous samples, one can incorporate models of the radiation impedance. In this study, different radiation impedance models are compared with two experimental examples. Thomasson’s model is compared to Rhazi’s method when...
5. Modelling of aircrew radiation exposure during solar particle events
Energy Technology Data Exchange (ETDEWEB)
Al Anid, H.; Lewis, B.J.; Bennett, L.G.I. [Royal Military College of Canada, Dept. of Chemistry and Chemical Engineering, Kingston, Ontario (Canada); Takada, M. [National Inst. of Radiological Science, International Space Radiation Lab., anagawa, Inage-Ku, Chiba (Japan)
2010-07-01
A transport code analysis using the Monte Carlo N-Particle eXtended code, MCNPX, has been used to propagate an extrapolated particle spectrum based on satellite measurements through the atmosphere to estimate radiation exposure during solar storms at high altitudes. Neutron monitor count rate data from stations around the world were used to benchmark the model calculations during a Ground Level Event. A comparison was made between the model predictions and actual flight measurements taken with various types of instruments used to measure the mixed radiation field during GLE 60. A computer-code has been developed to implement the model for routine analysis. (author)
6. Modelling of aircrew radiation exposure during solar particle events
Energy Technology Data Exchange (ETDEWEB)
Al Anid, H.; Lewis, B.J.; Bennett, L.G.I. [Royal Military College of Canada, Dept. of Chemistry and Chemical Engineering, Kingston, Ontario (Canada); Takada, M. [National Inst. of Radiological Science, International Space Radiation Lab., Anagawa, Inage-Ku, Chiba (Japan)
2011-03-15
A transport code analysis using the Monte Carlo N-Particle eXtended code, MCNPX, has been used to propagate an extrapolated particle spectrum based on satellite measurements through the atmosphere to estimate radiation exposure during solar storms at high altitudes. Neutron monitor count rate data from stations around the world were used to benchmark the model calculations during a Ground Level Event. A comparison was made between the model predictions and actual flight measurements taken with various types of instruments used to measure the mixed radiation field during GLE 60. A computer-code has been developed to implement the model for routine analysis. (author)
7. Modelling of aircrew radiation exposure from solar particle events
Energy Technology Data Exchange (ETDEWEB)
Al Anid, H.; Lewis, B.J.; Bennett, L.G.I. [Royal Military College of Canada, Dept. of Chemistry and Chemical Engineering, Kingston, Ontario (Canada)
2008-07-01
A transport code analysis using the Monte Carlo code, MCNPX, has been used to propagate an extrapolated particle spectrum based on GOES satellite measurements through the atmosphere to estimate aircrew radiation exposure due to solar particle events. Neutron monitor count rate data from ground stations around the world were used to benchmark the model calculations during several Ground Level Events (GLEs). In addition, a comparison was made between the model predictions and actual flight measurements made by some European investigators with various types of instrument used to measure the mixed radiation field during GLE 60 and 65. A computer-code has been further developed to implement the model for routine analysis. (author)
8. Leukocyte activity is altered in a ground based murine model of microgravity and proton radiation exposure.
Directory of Open Access Journals (Sweden)
Jenine K Sanzari
9. Radiation risk estimation based on measurement error models
CERN Document Server
Masiuk, Sergii; Shklyar, Sergiy; Chepurny, Mykola; Likhtarov, Illya
2017-01-01
This monograph discusses statistics and risk estimates applied to radiation damage under the presence of measurement errors. The first part covers nonlinear measurement error models, with a particular emphasis on efficiency of regression parameter estimators. In the second part, risk estimation in models with measurement errors is considered. Efficiency of the methods presented is verified using data from radio-epidemiological studies.
10. Adaptive deployment of model reductions for tau-leaping simulation.
Science.gov (United States)
Wu, Sheng; Fu, Jin; Petzold, Linda R
2015-05-28
Multiple time scales in cellular chemical reaction systems often render the tau-leaping algorithm inefficient. Various model reductions have been proposed to accelerate tau-leaping simulations. However, these are often identified and deployed manually, requiring expert knowledge. This is time-consuming and prone to error. In previous work, we proposed a methodology for automatic identification and validation of model reduction opportunities for tau-leaping simulation. Here, we show how the model reductions can be automatically and adaptively deployed during the time course of a simulation. For multiscale systems, this can result in substantial speedups.
11. Heterogeneity, quality, and reputation in an adaptive recommendation model
CERN Document Server
Cimini, Giulio; Zhou, Tao; Wei, Dong; Zhang, Yi-Cheng
2010-01-01
Recommender systems help people cope with the problem of information overload. A recently proposed adaptive news recommender model [Medo et al., 2009] is based on epidemic-like spreading of news in a social network. By means of agent-based simulations we study a "good get richer" feature of the model and determine which attributes are necessary for a user to play a leading role in the network. We further investigate the filtering efficiency of the model as well as its robustness against malicious and spamming behaviour. We show that incorporating user reputation in the recommendation process can substantially improve the outcome.
12. Direct Model Reference Adaptive Control for a Magnetic Bearing
Energy Technology Data Exchange (ETDEWEB)
Durling, Mike [Rensselaer Polytechnic Inst., Troy, NY (United States)
1999-11-01
A Direct Model Reference Adaptive Controller (DMRAC) is applied to a magnetic bearing test stand. The bearing of interest is the MBC 500 Magnetic Bearing System manufactured by Magnetic Moments, LLC. The bearing model is presented in state space form and the system transfer function is measured directly using a closed-loop swept sine technique. Next, the bearing models are used to design a phase-lead controller, notch filter and then a DMRAC. The controllers are tuned in simulations and finally are implemented using a combination of MATLAB, SIMULINK and dSPACE. The results show a successful implementation of a DMRAC on the magnetic bearing hardware.
13. Adaptive deployment of model reductions for tau-leaping simulation
Science.gov (United States)
Wu, Sheng; Fu, Jin; Petzold, Linda R.
2015-05-01
Multiple time scales in cellular chemical reaction systems often render the tau-leaping algorithm inefficient. Various model reductions have been proposed to accelerate tau-leaping simulations. However, these are often identified and deployed manually, requiring expert knowledge. This is time-consuming and prone to error. In previous work, we proposed a methodology for automatic identification and validation of model reduction opportunities for tau-leaping simulation. Here, we show how the model reductions can be automatically and adaptively deployed during the time course of a simulation. For multiscale systems, this can result in substantial speedups.
14. Adaptive modelling of structured molecular representations for toxicity prediction
Science.gov (United States)
Bertinetto, Carlo; Duce, Celia; Micheli, Alessio; Solaro, Roberto; Tiné, Maria Rosaria
2012-12-01
We investigated the possibility of modelling structure-toxicity relationships by direct treatment of the molecular structure (without using descriptors) through an adaptive model able to retain the appropriate structural information. With respect to traditional descriptor-based approaches, this provides a more general and flexible way to tackle prediction problems that is particularly suitable when little or no background knowledge is available. Our method employs a tree-structured molecular representation, which is processed by a recursive neural network (RNN). To explore the realization of RNN modelling in toxicological problems, we employed a data set containing growth impairment concentrations (IGC50) for Tetrahymena pyriformis.
15. [Comparison of three daily global solar radiation models].
Science.gov (United States)
Yang, Jin-Ming; Fan, Wen-Yi; Zhao, Ying-Hui
2014-08-01
Three daily global solar radiation estimation models ( Å-P model, Thornton-Running model and model provided by Liu Ke-qun et al.) were analyzed and compared using data of 13 weather stations from 1982 to 2012 from three northeastern provinces and eastern Inner Mongolia. After cross-validation analysis, the result showed that mean absolute error (MAE) for each model was 1.71, 2.83 and 1.68 MJ x m(-2) x d(-1) respectively, showing that Å-P model and model provided by Liu Ke-qun et al. which used percentage of sunshine had an advantage over Thornton-Running model which didn't use percentage of sunshine. Model provided by Liu Ke-qun et al. played a good effect on the situation of non-sunshine, and its MAE and bias percentage were 18.5% and 33.8% smaller than those of Å-P model, respectively. High precision results could be obtained by using the simple linear model of Å-P. Å-P model, Thornton-Running model and model provided by Liu Ke-qun et al. overvalued daily global solar radiation by 12.2%, 19.2% and 9.9% respectively. MAE for each station varied little with the spatial change of location, and annual MAE decreased with the advance of years. The reason for this might be that the change of observation accuracy caused by the replacement of radiation instrument in 1993. MAEs for rainy days, non-sunshine days and warm seasons of the three models were greater than those for days without rain, sunshine days and cold seasons respectively, showing that different methods should be used for different weather conditions on estimating solar radiation with meteorological elements.
16. Modern methods in collisional-radiative modeling of plasmas
CERN Document Server
2016-01-01
This book provides a compact yet comprehensive overview of recent developments in collisional-radiative (CR) modeling of laboratory and astrophysical plasmas. It describes advances across the entire field, from basic considerations of model completeness to validation and verification of CR models to calculation of plasma kinetic characteristics and spectra in diverse plasmas. Various approaches to CR modeling are presented, together with numerous examples of applications. A number of important topics, such as atomic models for CR modeling, atomic data and its availability and quality, radiation transport, non-Maxwellian effects on plasma emission, ionization potential lowering, and verification and validation of CR models, are thoroughly addressed. Strong emphasis is placed on the most recent developments in the field, such as XFEL spectroscopy. Written by leading international research scientists from a number of key laboratories, the book offers a timely summary of the most recent progress in this area. It ...
17. A coupled dynamical-radiational model of stratocumulus
Science.gov (United States)
Ye, Weizuo
1990-05-01
A model dealing with interactions between the air and low stratiform clouds is presented based on the mixed-layer model Lilly (1968) pioneered and on Deardorff's three dimensional numerical model results. Its main new aspects lie in 1) consideration of the natures of both the atmosphere and cloud; 2) a new entrainment velocity scheme with few arbitrary assumptions; 3) transition from one-mixed layer to two-mixed layer model; and 4) parameterization of radiation and precipitation calculations. The model results for radiation, moisture, and heat turbulent fluxes turn out to be in good agreement with those calculated or observed by Kawa (1988), Nicholls (1984), and Schmets et al. (1981) in California, the North Sea, and the North Atlantic, respectively. Basically, this paper furnishes the theoretical basis for a model to address questions concerning the time-evolution of thermodynamical profiles both in cloud and out of cloud. The applications of this model wil be in a separate paper.
18. General analysis of dark radiation in sequestered string models
Energy Technology Data Exchange (ETDEWEB)
Cicoli, Michele [ICTP,Strada Costiera 11, Trieste 34014 (Italy); Dipartimento di Fisica e Astronomia, Università di Bologna,via Irnerio 46, 40126 Bologna (Italy); INFN, Sezione di Bologna,via Irnerio 46, 40126 Bologna (Italy); Muia, Francesco [Dipartimento di Fisica e Astronomia, Università di Bologna,via Irnerio 46, 40126 Bologna (Italy); INFN, Sezione di Bologna,via Irnerio 46, 40126 Bologna (Italy)
2015-12-22
We perform a general analysis of axionic dark radiation produced from the decay of the lightest modulus in the sequestered LARGE Volume Scenario. We discuss several cases depending on the form of the Kähler metric for visible sector matter fields and the mechanism responsible for achieving a de Sitter vacuum. The leading decay channels which determine dark radiation predictions are to hidden sector axions, visible sector Higgses and SUSY scalars depending on their mass. We show that in most of the parameter space of split SUSY-like models squarks and sleptons are heavier than the lightest modulus. Hence dark radiation predictions previously obtained for MSSM-like cases hold more generally also for split SUSY-like cases since the decay channel to SUSY scalars is kinematically forbidden. However the inclusion of string loop corrections to the Kähler potential gives rise to a parameter space region where the decay channel to SUSY scalars opens up, leading to a significant reduction of dark radiation production. In this case, the simplest model with a shift-symmetric Higgs sector can suppress the excess of dark radiation ΔN{sub eff} to values as small as 0.14, in perfect agreement with current experimental bounds. Depending on the exact mass of the SUSY scalars all values in the range 0.14≲ΔN{sub eff}≲1.6 are allowed. Interestingly dark radiation overproduction can be avoided also in the absence of a Giudice-Masiero coupling.
19. Model of cell response to {\\alpha}-particle radiation
CERN Document Server
Liu, Longjian
2012-01-01
Starting from a general equation for organism (or cell system) growth and attributing additional cell death rate (besides the natural rate) to therapy, we derive an equation for cell response to {\\alpha} radiation. Different from previous models that are based on statistical theory, the present model connects the consequence of radiation with the growth process of a biosystem and each variable or parameter has meaning regarding the cell evolving process. We apply this equation to model the dose response for {\\alpha}-particle radiation. It interprets the results of both high and low linear energy transfer (LET) radiations. When LET is high, the additional death rate is a constant, which implies that the localized cells are damaged immediately and the additional death rate is proportional to the number of cells present. While at low LET, the additional death rate includes a constant term and a linear term of radiation dose, implying that the damage to some cell nuclei has a time accumulating effect. This model ...
20. Research on Dependable Ionizing Radiation Protection based on Model i*
Directory of Open Access Journals (Sweden)
Tan Hai
2013-07-01
Full Text Available The software’s unreliability mostly attributes to an erroneous analysis on the requirements done at the beginning. In this paper, we apply the tool of i* frame requirement modeling and build early requirement model against ionizing radiation. After finding out possible risks and corresponding solutions during the process of modeling analysis, we propose reasoning models against ionizing radiation. The radiation protection system with the above models can figure out the purpose of agents related to radiant source and provide normal service even when the environment software system is being interfered. It can serve the ecological and economical society with stability and development. The model is divided into several sections. Section 1 gives the outline of the dependant software. Section 2 illustrates the i* frame technology. Section 3, 4 and 5 cover the topic of dependant security requirement analysis, SD&SR model on ionizing radiation respectively. Section 6 gives the conclusion.
1. Radiation Belt Modeling for Spacecraft Design: Model Comparisons for Common Orbits
Science.gov (United States)
Lauenstein, J.-M.; Barth, J. L.
2005-01-01
We present the current status of radiation belt modeling, providing model details and comparisons with AP-8 and AE-8 for commonly used orbits. Improved modeling of the particle environment enables smarter space system design.
2. Modelling radiation damage to ESA's Gaia satellite CCDs
CERN Document Server
Seabroke, G M; Cropper, M S
2008-01-01
The Gaia satellite is a high-precision astrometry, photometry and spectroscopic ESA cornerstone mission, currently scheduled for launch in late 2011. Its primary science drivers are the composition, formation and evolution of the Galaxy. Gaia will achieve its scientific requirements with detailed calibration and correction for radiation damage. Microscopic models of Gaia's CCDs are being developed to simulate the charge trapping effect of radiation damage, which causes charge transfer inefficiency. The key to calculating the probability of a photoelectron being captured by a trap is the 3D electron density within each CCD pixel. However, this has not been physically modelled for Gaia CCD pixels. In this paper, the first of a series, we motivate the need for such specialised 3D device modelling and outline how its future results will fit into Gaia's overall radiation calibration strategy.
3. Modeling gravitational radiation from coalescing binary black holes
CERN Document Server
Baker, J; Loustó, C O; Takahashi, R
2002-01-01
With the goal of bringing theory, particularly numerical relativity, to bear on an astrophysical problem of critical interest to gravitational wave observers we introduce a model for coalescence radiation from binary black hole systems. We build our model using the "Lazarus approach", a technique that bridges far and close limit approaches with full numerical relativity to solve Einstein equations applied in the truly nonlinear dynamical regime. We specifically study the post-orbital radiation from a system of equal-mass non-spinning black holes, deriving waveforms which indicate strongly circularly polarized radiation of roughly 3% of the system's total energy and 12% of its total angular momentum in just a few cycles. Supporting this result we first establish the reliability of the late-time part of our model, including the numerical relativity and close-limit components, with a thorough study of waveforms from a sequence of black hole configurations varying from previously treated head-on collisions to rep...
4. Model-Free Adaptive Control Algorithm with Data Dropout Compensation
OpenAIRE
Xuhui Bu; Fashan Yu; Zhongsheng Hou; Hongwei Zhang
2012-01-01
The convergence of model-free adaptive control (MFAC) algorithm can be guaranteed when the system is subject to measurement data dropout. The system output convergent speed gets slower as dropout rate increases. This paper proposes a MFAC algorithm with data compensation. The missing data is first estimated using the dynamical linearization method, and then the estimated value is introduced to update control input. The convergence analysis of the proposed MFAC algorithm is given, and the effe...
CERN Document Server
Shcherbakov, Dmitry; Günther, Michael; Finkenrath, Jacob; Knechtli, Francesco; Peardon, Michael
2016-01-01
We study a novel class of numerical integrators, the adapted nested force-gradient schemes, used within the molecular dynamics step of the Hybrid Monte Carlo (HMC) algorithm. We test these methods in the Schwinger model on the lattice, a well known benchmark problem. We derive the analytical basis of nested force-gradient type methods and demonstrate the advantage of the proposed approach, namely reduced computational costs compared with other numerical integration schemes in HMC.
6. Stationary radiation cataracts: an animal model
Energy Technology Data Exchange (ETDEWEB)
Holsclaw, D.S.; Merriam, G.R. Jr; Medvedovsky, C.; Worgul, B.V. (Columbia Univ., New York, NY (USA)); Rothstein, H. (Fordham Univ., New York, NY (USA))
1989-03-01
This report describes the induction of stationary radiation cataracts in postmetamorphic bullfrogs following ocular irradiation with a 10 Gy dose of X-rays. The eyes of non-irradiated animals and animals irradiated with 25 Gy served as controls. The 25 Gy irradiated lenses rapidly progressed to complete opacification (4+) by 26 weeks, while lenses exposed to 10 Gy advanced to the 2.5+ stage by 35 weeks and progressed no further. In the lower dose lenses, transparent cortex began to appear anteriorly and posteriorly between the capsule and opaque fibers at 45 weeks. As the clear fibers accumulated, the disrupted region came to occupy increasingly deeper cortex. Histologically, opacities in both groups were preceded by disorganization of the bow cytoarchitecture, meridional row disorganization, and the appearance in the lens epithelium of nuclear polymorphism, fragmented nuclei, micronuclei, clusters of nuclei, and abnormal mitotic figures. In the lenses exposed to the 25 Gy dose, this damage continued to worsen, so that the 4+ stage was characterized by extensive epithelial cell death, absence of the lens bow, degenerated fiber masses, and liquefied substrata. In contrast, prior to the appearance of transparent cortex in the 10 Gy group, the lens epithelial aberrations, arc of the bow, and meridional row disorganization were all observed to improve. Further, by 69 weeks, the lens epithelium appeared as a largely homogeneous population, and the meridional rows and the arc of the bow had become reestablished. (author).
7. Goal-oriented model adaptivity for viscous incompressible flows
KAUST Repository
van Opstal, T. M.
2015-04-04
© 2015, Springer-Verlag Berlin Heidelberg. In van Opstal et al. (Comput Mech 50:779–788, 2012) airbag inflation simulations were performed where the flow was approximated by Stokes flow. Inside the intricately folded initial geometry the Stokes assumption is argued to hold. This linearity assumption leads to a boundary-integral representation, the key to bypassing mesh generation and remeshing. It therefore enables very large displacements with near-contact. However, such a coarse assumption cannot hold throughout the domain, where it breaks down one needs to revert to the original model. The present work formalizes this idea. A model adaptive approach is proposed, in which the coarse model (a Stokes boundary-integral equation) is locally replaced by the original high-fidelity model (Navier–Stokes) based on a-posteriori estimates of the error in a quantity of interest. This adaptive modeling framework aims at taking away the burden and heuristics of manually partitioning the domain while providing new insight into the physics. We elucidate how challenges pertaining to model disparity can be addressed. Essentially, the solution in the interior of the coarse model domain is reconstructed as a post-processing step. We furthermore present a two-dimensional numerical experiments to show that the error estimator is reliable.
8. Network and adaptive system of systems modeling and analysis.
Energy Technology Data Exchange (ETDEWEB)
Lawton, Craig R.; Campbell, James E. Dr. (.; .); Anderson, Dennis James; Eddy, John P.
2007-05-01
This report documents the results of an LDRD program entitled ''Network and Adaptive System of Systems Modeling and Analysis'' that was conducted during FY 2005 and FY 2006. The purpose of this study was to determine and implement ways to incorporate network communications modeling into existing System of Systems (SoS) modeling capabilities. Current SoS modeling, particularly for the Future Combat Systems (FCS) program, is conducted under the assumption that communication between the various systems is always possible and occurs instantaneously. A more realistic representation of these communications allows for better, more accurate simulation results. The current approach to meeting this objective has been to use existing capabilities to model network hardware reliability and adding capabilities to use that information to model the impact on the sustainment supply chain and operational availability.
9. An Adaptive Approach to Schema Classification for Data Warehouse Modeling
Institute of Scientific and Technical Information of China (English)
Hong-Ding Wang; Yun-Hai Tong; Shao-Hua Tan; Shi-Wei Tang; Dong-Qing Yang; Guo-Hui Sun
2007-01-01
Data warehouse (DW) modeling is a complicated task, involving both knowledge of business processes and familiarity with operational information systems structure and behavior. Existing DW modeling techniques suffer from the following major drawbacks -data-driven approach requires high levels of expertise and neglects the requirements of end users, while demand-driven approach lacks enterprise-wide vision and is regardless of existing models of underlying operational systems. In order to make up for those shortcomings, a method of classification of schema elements for DW modeling is proposed in this paper. We first put forward the vector space models for subjects and schema elements, then present an adaptive approach with self-tuning theory to construct context vectors of subjects, and finally classify the source schema elements into different subjects of the DW automatically. Benefited from the result of the schema elements classification, designers can model and construct a DW more easily.
10. Language Model Combination and Adaptation Using Weighted Finite State Transducers
Science.gov (United States)
Liu, X.; Gales, M. J. F.; Hieronymus, J. L.; Woodland, P. C.
2010-01-01
In speech recognition systems language model (LMs) are often constructed by training and combining multiple n-gram models. They can be either used to represent different genres or tasks found in diverse text sources, or capture stochastic properties of different linguistic symbol sequences, for example, syllables and words. Unsupervised LM adaption may also be used to further improve robustness to varying styles or tasks. When using these techniques, extensive software changes are often required. In this paper an alternative and more general approach based on weighted finite state transducers (WFSTs) is investigated for LM combination and adaptation. As it is entirely based on well-defined WFST operations, minimum change to decoding tools is needed. A wide range of LM combination configurations can be flexibly supported. An efficient on-the-fly WFST decoding algorithm is also proposed. Significant error rate gains of 7.3% relative were obtained on a state-of-the-art broadcast audio recognition task using a history dependently adapted multi-level LM modelling both syllable and word sequences
11. Adaptation of a canopy reflectance model for sub-aqueous vegetation: Definition and sensitivity analysis
Energy Technology Data Exchange (ETDEWEB)
Plummer, S.E. [NERC/RSADU, Cambridgeshire (United Kingdom); Malthus, T.J. [Univ. of Edinburgh (United Kingdom); Clark, C.D. [Univ. of Sheffield (United Kingdom)
1997-06-01
Seagrass meadows are a key component of shallow coastal environments acting as a food resource, nursery and contributing to water oxygenation. Given the importance of these meadows and their susceptibility to anthropogenic disturbance, it is vital that the extent and growth of seagrass is monitored. Remote sensing techniques offer the potential to determine biophysical characteristics of seagrass. This paper presents observations on the development and testing of an invertible model of seagrass canopy reflectance. The model is an adaptation of a land surface reflectance model to incorporate the effects of attenuation and scattering of incoming radiative flux in water. Sensitivity analysis reveals that the subsurface reflectance is strongly dependent on the water depth, vegetation amount, the parameter which we wish to determine, and turbidity respectively. By contrast the chlorophyll concentration of water and gelbstoff are relatively unimportant. Water depth and turbidity need to be known or accommodated in any inversion as free parameters.
12. Childhood dental injuries: a resiliency model of adaptation.
Science.gov (United States)
Porritt, Jenny M; Rodd, Helen D; Baker, Sarah R
2015-07-01
There is a paucity of research examining how children and their families adapt to traumatic dental injuries. This study examined how clinical and psychosocial factors influence adaptation to this oral stressor using a theoretical framework of resiliency and adaptation. Children with traumatised permanent teeth, who were attending a UK dental hospital, completed questionnaires at baseline and at a 6 month follow-up. Child questionnaires assessed coping styles, social support, and quality of life outcomes. Parents were also asked to complete questionnaires, which assessed previous stressors/strains on the family, social support, healthcare satisfaction, and family impacts. Data related to the child's dental injury were collected from clinical notes. Structural equation modelling and regression analyses were employed to analyse data. One hundred and eight children and 113 parents participated at baseline. Children's gender, coping style, social support, and family functioning significantly predicted children's oral health-related quality of life. Parents' satisfaction with their children's dental care significantly predicted parental quality of life outcomes. Children's close friend support and healthcare satisfaction remained significant predictors of positive outcomes at follow-up. The findings revealed important psychosocial factors that influence child and family adaptation to childhood dental trauma. © 2014 BSPD, IAPD and John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
13. Local Adaptive Calibration of the GLASS Surface Incident Shortwave Radiation Product Using Smoothing Spline
Science.gov (United States)
Zhang, X.; Liang, S.; Wang, G.
2015-12-01
Incident solar radiation (ISR) over the Earth's surface plays an important role in determining the Earth's climate and environment. Generally, can be obtained from direct measurements, remotely sensed data, or reanalysis and general circulation models (GCMs) data. Each type of product has advantages and limitations: the surface direct measurements provide accurate but sparse spatial coverage, whereas other global products may have large uncertainties. Ground measurements have been normally used for validation and occasionally calibration, but transforming their "true values" spatially to improve the satellite products is still a new and challenging topic. In this study, an improved thin-plate smoothing spline approach is presented to locally "calibrate" the Global LAnd Surface Satellite (GLASS) ISR product using the reconstructed ISR data from surface meteorological measurements. The influences of surface elevation on ISR estimation was also considered in the proposed method. The point-based surface reconstructed ISR was used as the response variable, and the GLASS ISR product and the surface elevation data at the corresponding locations as explanatory variables to train the thin plate spline model. We evaluated the performance of the approach using the cross-validation method at both daily and monthly time scales over China. We also evaluated estimated ISR based on the thin-plate spline method using independent ground measurements at 10 sites from the Coordinated Enhanced Observation Network (CEON). These validation results indicated that the thin plate smoothing spline method can be effectively used for calibrating satellite derived ISR products using ground measurements to achieve better accuracy.
14. Statistical Modeling for Radiation Hardness Assurance
Science.gov (United States)
2014-01-01
We cover the models and statistics associated with single event effects (and total ionizing dose), why we need them, and how to use them: What models are used, what errors exist in real test data, and what the model allows us to say about the DUT will be discussed. In addition, how to use other sources of data such as historical, heritage, and similar part and how to apply experience, physics, and expert opinion to the analysis will be covered. Also included will be concepts of Bayesian statistics, data fitting, and bounding rates.
15. The adaptive statistical iterative reconstruction-V technique for radiation dose reduction in abdominal CT: comparison with the adaptive statistical iterative reconstruction technique.
Science.gov (United States)
Kwon, Heejin; Cho, Jinhan; Oh, Jongyeong; Kim, Dongwon; Cho, Junghyun; Kim, Sanghyun; Lee, Sangyun; Lee, Jihyun
2015-10-01
To investigate whether reduced radiation dose abdominal CT images reconstructed with adaptive statistical iterative reconstruction V (ASIR-V) compromise the depiction of clinically competent features when compared with the currently used routine radiation dose CT images reconstructed with ASIR. 27 consecutive patients (mean body mass index: 23.55 kg m(-2) underwent CT of the abdomen at two time points. At the first time point, abdominal CT was scanned at 21.45 noise index levels of automatic current modulation at 120 kV. Images were reconstructed with 40% ASIR, the routine protocol of Dong-A University Hospital. At the second time point, follow-up scans were performed at 30 noise index levels. Images were reconstructed with filtered back projection (FBP), 40% ASIR, 30% ASIR-V, 50% ASIR-V and 70% ASIR-V for the reduced radiation dose. Both quantitative and qualitative analyses of image quality were conducted. The CT dose index was also recorded. At the follow-up study, the mean dose reduction relative to the currently used common radiation dose was 35.37% (range: 19-49%). The overall subjective image quality and diagnostic acceptability of the 50% ASIR-V scores at the reduced radiation dose were nearly identical to those recorded when using the initial routine-dose CT with 40% ASIR. Subjective ratings of the qualitative analysis revealed that of all reduced radiation dose CT series reconstructed, 30% ASIR-V and 50% ASIR-V were associated with higher image quality with lower noise and artefacts as well as good sharpness when compared with 40% ASIR and FBP. However, the sharpness score at 70% ASIR-V was considered to be worse than that at 40% ASIR. Objective image noise for 50% ASIR-V was 34.24% and 46.34% which was lower than 40% ASIR and FBP. Abdominal CT images reconstructed with ASIR-V facilitate radiation dose reductions of to 35% when compared with the ASIR. This study represents the first clinical research experiment to use ASIR-V, the newest version of
16. A Computational Model of Cellular Response to Modulated Radiation Fields
Energy Technology Data Exchange (ETDEWEB)
McMahon, Stephen J., E-mail: [email protected] [Centre for Cancer Research and Cell Biology, Queen' s University Belfast, Belfast, Northern Ireland (United Kingdom); Butterworth, Karl T. [Centre for Cancer Research and Cell Biology, Queen' s University Belfast, Belfast, Northern Ireland (United Kingdom); McGarry, Conor K. [Centre for Cancer Research and Cell Biology, Queen' s University Belfast, Belfast, Northern Ireland (United Kingdom); Radiotherapy Physics, Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Northern Ireland (United Kingdom); Trainor, Colman [Centre for Cancer Research and Cell Biology, Queen' s University Belfast, Belfast, Northern Ireland (United Kingdom); O' Sullivan, Joe M. [Centre for Cancer Research and Cell Biology, Queen' s University Belfast, Belfast, Northern Ireland (United Kingdom); Clinical Oncology, Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, Northern Ireland (United Kingdom); Hounsell, Alan R. [Centre for Cancer Research and Cell Biology, Queen' s University Belfast, Belfast, Northern Ireland (United Kingdom); Radiotherapy Physics, Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Northern Ireland (United Kingdom); Prise, Kevin M. [Centre for Cancer Research and Cell Biology, Queen' s University Belfast, Belfast, Northern Ireland (United Kingdom)
2012-09-01
17. Radiative transfer model for contaminated rough slabs
CERN Document Server
Andrieu, François; Schmidt, Frédéric; Schmitt, Bernard
2015-01-01
We present a semi-analytical model to simulate bidirectional reflectance distribution function (BRDF) spectra of a rough slab layer containing impurities. This model has been optimized for fast computation in order to analyze hyperspectral data. We designed it for planetary surfaces ices studies but it could be used for other purposes. It estimates the bidirectional reflectance of a rough slab of material containing inclusions, overlaying an optically thick media (semi-infinite media or stratified media, for instance granular material). The inclusions are supposed to be close to spherical, and of any type of other material than the ice matrix. It can be any type of other ice, mineral or even bubbles, defined by their optical constants. We suppose a low roughness and we consider the geometrical optics conditions. This model is thus applicable for inclusions larger than the considered wavelength. The scattering on the inclusions is assumed to be isotropic. This model has a fast computation implementation and th...
18. Atmospheric transmittance model for photosynthetically active radiation
Energy Technology Data Exchange (ETDEWEB)
Paulescu, Marius; Stefu, Nicoleta; Gravila, Paul; Paulescu, Eugenia; Boata, Remus; Pacurar, Angel; Mares, Oana [Physics Department, West University of Timisoara, V Parvan 4, 300223 Timisoara (Romania); Pop, Nicolina [Department of Physical Foundations of Engineering, Politehnica University of Timisoara, V Parvan 2, 300223 Timisoara (Romania); Calinoiu, Delia [Mechanical Engineering Faculty, Politehnica University of Timisoara, Mihai Viteazu 1, 300222 Timisoara (Romania)
2013-11-13
A parametric model of the atmospheric transmittance in the PAR band is presented. The model can be straightforwardly applied for calculating the beam, diffuse and global components of the PAR solar irradiance. The required inputs are: air pressure, ozone, water vapor and nitrogen dioxide column content, Ångström's turbidity coefficient and single scattering albedo. Comparison with other models and ground measured data shows a reasonable level of accuracy for this model, making it suitable for practical applications. From the computational point of view the calculus is condensed into simple algebra which is a noticeable advantage. For users interested in speed-intensive computation of the effective PAR solar irradiance, a PC program based on the parametric equations along with a user guide are available online at http://solar.physics.uvt.ro/srms.
19. Automatic online adaptive radiation therapy techniques for targets with significant shape change: a feasibility study.
Science.gov (United States)
Court, Laurence E; Tishler, Roy B; Petit, Joshua; Cormack, Robert; Chin, Lee
2006-05-21
This work looks at the feasibility of an online adaptive radiation therapy concept that would detect the daily position and shape of the patient, and would then correct the daily treatment to account for any changes compared with planning position. In particular, it looks at the possibility of developing algorithms to correct for large complicated shape change. For co-planar beams, the dose in an axial plane is approximately associated with the positions of a single multi-leaf collimator (MLC) pair. We start with a primary plan, and automatically generate several secondary plans with gantry angles offset by regular increments. MLC sequences for each plan are calculated keeping monitor units (MUs) and number of segments constant for a given beam (fluences are different). Bulk registration (3D) of planning and daily CT images gives global shifts. Slice-by-slice (2D) registration gives local shifts and rotations about the longitudinal axis for each axial slice. The daily MLC sequence is then created for each axial slice/MLC leaf pair combination, by taking the MLC positions from the pre-calculated plan with the nearest rotation, and shifting using a beam's-eye-view calculation to account for local linear shifts. A planning study was carried out using two head and neck region MR images of a healthy volunteer which were contoured to simulate a base-of-tongue treatment: one with the head straight (used to simulate the planning image) and the other with the head tilted to the left (the daily image). Head and neck treatment was chosen to evaluate this technique because of its challenging nature, with varying internal and external contours, and multiple degrees of freedom. Shape change was significant: on a slice-by-slice basis, local rotations in the daily image varied from 2 to 31 degrees, and local shifts ranged from -0.2 to 0.5 cm and -0.4 to 0.0 cm in right-left and posterior-anterior directions, respectively. The adapted treatment gave reasonable target coverage (100
20. A biokinetic model for zinc for use in radiation protection
Energy Technology Data Exchange (ETDEWEB)
Leggett, R.W., E-mail: [email protected]
2012-03-15
1. Modelling the luminous efficacy of solar radiation
Energy Technology Data Exchange (ETDEWEB)
2000-07-01
The global and diffuse luminous efficacy models proposed in Muneer (1995), Muneer and Kinghorn (1997), have been tested with experimental data obtained in Madrid. When the models with local coefficients are statistically assessed with local data, global illuminance L{sub g} is estimated with an acceptable accuracy, but diffuse illuminance L{sub d} is overestimated for L{sub d} higher than about 25 klux. (author)
2. Radiation Background and Attenuation Model Validation and Development
Energy Technology Data Exchange (ETDEWEB)
Peplow, Douglas E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Santiago, Claudio P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
2015-08-05
This report describes the initial results of a study being conducted as part of the Urban Search Planning Tool project. The study is comparing the Urban Scene Simulator (USS), a one-dimensional (1D) radiation transport model developed at LLNL, with the three-dimensional (3D) radiation transport model from ORNL using the MCNP, SCALE/ORIGEN and SCALE/MAVRIC simulation codes. In this study, we have analyzed the differences between the two approaches at every step, from source term representation, to estimating flux and detector count rates at a fixed distance from a simple surface (slab), and at points throughout more complex 3D scenes.
3. Analytical Heat Transfer Modeling of a New Radiation Calorimeter
CERN Document Server
Ndong, Elysée Obame; Aitken, Frédéric
2016-01-01
This paper deals with an analytical modeling of heat transfers simulating a new radiation calorimeter operating in a temperature range from -50 {\\deg}C to 150 {\\deg}C. The aim of this modeling is the evaluation of the feasibility and performance of the calorimeter by assessing the measurement of power losses of some electrical devices by radiation, the influence of the geometry and materials. Finally a theoretical sensibility of the new apparatus is estimated at ~1 mW. From these results the calorimeter has been successfully implemented and patented.
4. Continuum radiative transfer Modeling of Sagittarius B2
OpenAIRE
Schmiedeke, A.; Schilke, P.; Möller, Th.; Sánchez-Monge, Á.; Bergin, E.; Comito, C.; Csengeri, T.; Lis, D. C.; Molinari, S.; Qin, S.L.; Rolffs, R.
2016-01-01
We present results from radiative transfer modeling of the continuum emission towards Sagittarius B2 (hereafter Sgr B2). We have developed a radiative transfer framework – Pandora – that employs RADMC-3D (Dullemond 2012) for a self-consistent determination of the dust temperature. With this pipeline, we have set-up a single model that consistently reproduces the thermal dust and free-free continuum emission of Sgr B2 spanning four orders of magnitude in spatial scales (0.02–45 pc) and two ord...
5. Metodi predittivi per Adaptive Radiation Theraphy: effetti del movimento d'organo, degli algoritmi di registrazione deformabile e dell'accumulo di dose
OpenAIRE
2016-01-01
Il lavoro di ricerca è finanziato dal Ministero della Salute - Bando Giovani Ricercatori 2010 MoH (GR-2010-2318757) “Dose warping methods for IGRT and Adaptive
|
{"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": 0.7075252532958984, "perplexity": 4554.846476363793}, "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/1510934805914.1/warc/CC-MAIN-20171120052322-20171120072322-00049.warc.gz"}
|
https://demo.formulasearchengine.com/wiki/Ives%E2%80%93Stilwell_experiment
|
# Ives–Stilwell experiment
Ives–Stilwell experiment (1938). "Canal rays" (a mixture of mostly H2+ and H3+ ions) were accelerated through perforated plates charged from 6,788 to 18,350 volts. The beam and its reflected image were simultaneously observed with the aid of a concave mirror offset 7° from the beam.[1] (The offset in this illustration is exaggerated.)
The Ives–Stilwell experiment tested the contribution of relativistic time dilation to the Doppler shift of light.[1][2] The result was in agreement with the formula for the transverse Doppler effect, and was the first direct, quantitative confirmation of the time dilation factor. Since then, many Ives–Stilwell type experiments have been performed with increased precision. Together with the Michelson–Morley and Kennedy–Thorndike experiments, it forms one of the fundamental tests of special relativity theory.[3] Other tests confirming the relativistic Doppler effect, are the Mössbauer rotor experiment and modern Ives–Stilwell experiments. For other time dilation experiments, see Time dilation of moving particles. For general overview, see Tests of special relativity.
Both time dilation and the relativistic Doppler effect were predicted by Albert Einstein in his seminal 1905 paper.[4] Einstein subsequently (1907) suggested an experiment based on the measurement of the relative frequencies of light perceived as arriving from a light source in motion with respect to the observer, and he calculated the additional Doppler shift due to time dilation.[5] This effect was later called "transverse Doppler effect" (TDE), since such experiments were initially imagined to be conducted at right angles with respect to the moving source, in order to avoid the influence of the longitudinal Doppler shift. Eventually, Herbert E. Ives and G. R. Stilwell (referring to time dilation as following from the theory of Lorentz and Larmor) gave up the idea of measuring this effect at right angles. They used rays in longitudinal direction and found a way to separate the much smaller TDE from the much bigger longitudinal Doppler effect. The experiment was performed in 1938[1] and it was reprised several times (see, e.g.[2]). Similar experiments were conducted several times with increased precision, by Otting (1939),[6] Mandelberg et al. (1962),[7] Hasselkamp et al. (1979),[8]
## Experiments with "canal rays"
### The experiment of 1938
Ives remarked that it is nearly impossible to measure the transverse Doppler effect with respect to light rays emitted by canal rays at right angles to the direction of motion of the canal rays (as it was considered earlier by Einstein), because the influence of the longitudinal effect can hardly be excluded. Therefore he developed a method, to observe the effect in the longitudinal direction of the canal rays' motion. If it is assumed that the speed of light is fixed with respect to the observer ("classical theory"), then the forward and rearward Doppler-shifted frequencies seen on a moving object will be
${\displaystyle {\frac {f_{o}}{f_{s}}}={\frac {c}{c\pm v}},}$
where v is recession velocity. Under special relativity, the two frequencies will also include an additional Lorentz factor redshift correction represented by the TDE formula:
${\displaystyle {\frac {f_{o}}{f_{s}}}={\sqrt {1-{\frac {v^{2}}{c^{2}}}}}}$
When we invert these relationships so that they relate to wavelengths rather than frequencies, "classical theory" predicts redshifted and blueshifted wavelength values of 1 + v/c and 1 − v/c, so if all three wavelengths (redshifted, blueshifted and original) are marked on a linear scale, according to classical theory the three marks should be perfectly evenly spaced.
${\displaystyle |\cdot \cdot \cdot \cdot \cdot |\cdot \cdot \cdot \cdot \cdot |\,}$
But if the light is shifted by special relativity's predictions, the additional Lorentz offset means that the two outer marks will be offset in the same direction with respect to the central mark.
${\displaystyle |\cdot \cdot \cdot \cdot |\cdot \cdot \cdot \cdot \cdot \cdot |\,}$
Ives and Stilwell found that there was a significant offset of the centre of gravity of the three marks, and therefore the Doppler relationship was not that of "classical theory".
Why it is difficult to measure the transverse Doppler effect accurately using a transverse beam. The illustration shows the results of attempting to measure the 4861 ångström line emitted by a beam of "canal rays" as they recombine with electrons stripped from the dilute hydrogen gas used to fill the canal ray tube. With v = 0.005 c, the predicted result of the TDE would be a 4861.06 ångström line. On the left, conventional Doppler shift results in broadening the emission line to such an extent that the TDE cannot be observed. In the middle, we see that even if one narrows one's view to the exact center of the beam, very small deviations of the beam from an exact right angle introduce shifts comparable to the predicted effect. Ives and Stilwell used a concave mirror that allowed them to simultaneously observe a nearly longitudinal direct beam (blue) and its reflected image (red). Spectroscopically, three lines would be observed: An undisplaced emission line, and blueshifted and redshifted lines. The average of the redshifted and blueshifted lines was compared with the undisplaced line.
1. It didn't require a commitment to an exact value for the velocity involved (which might have been theory-dependent).
2. It didn't require an understanding or interpretation of angular aberration effects, as might have been required for the analysis of a "true" transverse test. A "true transverse test" was run almost 40 years later by Hasselkamp in 1979.[8]
### The experiment of 1941
In the 1938 experiment, the maximum TDE was limited to 0.047 Å. The chief difficulty that Ives and Stilwell encountered in attempts to achieve larger shifts was that when they raised the electric potential between the accelerating electrodes to above 20,000 volts, breakdown and sparking would occur that could lead to destruction of the tube.
This difficulty was overcome by using multiple electrodes. Using a four electrode version of the canal ray tube with three gaps, a total potential difference of 43,000 volts could be achieved. A voltage drop of 5,000 volts was used across the first gap, while the remaining voltage drop was distributed between the second and third gaps. With this tube, a highest shift of 0.11 Å was achieved for H2+ ions.
Other aspects of the experiment were also improved. Careful tests showed that the "undisplaced" particles yielding the central line actually acquired a small velocity imparted to them in the same direction of motion as the moving particles (no more than about 750 meters per second). Under normal circumstances, this would be of no consequence, since this effect would only result in a slight apparent broadening of the direct and reflected images of the central line. But if the mirror were tarnished, the central line might be expected to shift slightly. Other controls were performed to address various objections of critics of the original experiment.
The net result of all of this attention to detail was the complete verification of Ives and Stilwell's 1938 results and the extension of these results to higher speeds.[2]
## Mössbauer rotor experiments
The Kündig experiment (1963). An 57Fe Mössbauer absorber was mounted 9.3 cm from the axis of an ultracentrifuge rotor. A 57Co source was mounted on a piezoelectric transducer (PZT) at the rotor center. Spinning the rotor caused the source and absorber to fall out of resonance. A modulated voltage applied to the PZT set the source in radial motion relative to the absorber, so that the amount of conventional Doppler shift that would restore resonance could be measured. For example, withdrawing the source at 195 µm/s produced a conventional Doppler redshift equivalent to the TDE resulting from spinning the absorber at 35,000 rpm.
### Relativistic Doppler effect
A more precise confirmation of the relativistic Doppler effect was achieved by the Mössbauer rotor experiments. From a source in the middle of a rotating disk, gamma rays are sent to a receiver at the rim (in some variations this scheme was reversed). Due to the rotation velocity of the receiver, the absorption frequency decreases if the transverse Doppler effect exists. This effect was actually observed using the Mössbauer effect. The maximal deviation from time dilation was 10−5, thus the precision was much higher than that (10−2) of the Ives–Stilwell experiments. Such experiments were performed by Hay et al. (1960),[9] Champeney et al. (1963, 1965),[10][11] Kündig (1963).[12]
### Isotropy of the speed of light
Moessbauer rotor experiments were also used to measure a possible anisotropy of the speed of light. That is, a possible aether wind should exert a disturbing influence on the absorption frequency. However, as in all other aether drift experiments (Michelson–Morley experiment), the result was negative, putting an upper limit to aether drift of 3–4 m/s. Experiments of that kind were performed by Champeney & Moon (1961),[13] Champeney et al. (1963)[14] and Turner & Hill (1964).[15]
## Modern experiments
### Fast moving clocks
A considerably higher precision has been achieved in modern variations of Ives–Stilwell experiments. In heavy ion storage rings, as the TSR at the MPIK, the Doppler shift of lithium ions traveling at high speeds is evaluated by using saturated spectroscopy. Due to their frequencies emitted, these ions can be considered as optical atomic clocks of high precision.
Author Year Speed Maximum deviation from time dilation
Grieser et al.[16] 1994 0.064 c ≤ Template:Val
Saathoff et al.[17] 2003 0.064 c ≤ Template:Val
Reinhardt et al.[18] 2007 0.064 c ≤ Template:Val
Novotny et al.[19] 2009 0.34 c ≤ Template:Val
Botermann et al.[20] 2014 0.338 c ≤ Template:Val
### Slow moving clocks
Meanwhile, the measurement of time dilation at everyday speeds has been accomplished as well. Chou et al. (2010) created two clocks each holding a single 27Al+ ion in a Paul trap. In one clock, the Al+ ion was accompanied by a 9Be+ ion as a "logic" ion, while in the other, it was accompanied by a 25Mg+ ion. The two clocks were situated in separate laboratories and connected with a 75 m long, phase-stabilized optical fiber for exchange of clock signals. These optical atomic clocks emitted frequencies in the petahertz (1 PHz = 1015 Hz) range and had frequency uncertainties in the 10−17 range. With these clocks, it was possible to measure a frequency shift due to time dilation of ∼10−16 at speeds below 36 km/h (< 10 m/s, the speed of a fast runner) by comparing the rates of moving and resting aluminum ions. It was also possible to detect gravitational time dilation from a difference in elevation between the two clocks of 33 cm.[21]
## References
1. {{#invoke:Citation/CS1|citation |CitationClass=journal }}
2. {{#invoke:Citation/CS1|citation |CitationClass=journal }}
3. {{#invoke:Citation/CS1|citation |CitationClass=journal }}
4. {{#invoke:Citation/CS1|citation |CitationClass=journal }} English translation: ‘On the Electrodynamics of Moving Bodies’
5. {{#invoke:Citation/CS1|citation |CitationClass=journal }}
6. {{#invoke:Citation/CS1|citation |CitationClass=journal }}
7. {{#invoke:Citation/CS1|citation |CitationClass=journal }}
8. {{#invoke:Citation/CS1|citation |CitationClass=journal }}
9. {{#invoke:Citation/CS1|citation |CitationClass=journal }}
10. {{#invoke:Citation/CS1|citation |CitationClass=journal }}
11. {{#invoke:Citation/CS1|citation |CitationClass=journal }}
12. {{#invoke:Citation/CS1|citation |CitationClass=journal }}
13. {{#invoke:Citation/CS1|citation |CitationClass=journal }}
14. {{#invoke:Citation/CS1|citation |CitationClass=journal }}
15. {{#invoke:Citation/CS1|citation |CitationClass=journal }}
16. {{#invoke:Citation/CS1|citation |CitationClass=journal }}
17. {{#invoke:Citation/CS1|citation |CitationClass=journal }}
18. {{#invoke:Citation/CS1|citation |CitationClass=journal }}
19. {{#invoke:Citation/CS1|citation |CitationClass=journal }}
20. {{#invoke:Citation/CS1|citation |CitationClass=journal }}
21. {{#invoke:Citation/CS1|citation |CitationClass=journal }}
|
{"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 4, "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": 0.8733988404273987, "perplexity": 1753.3391549866576}, "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/1568514575844.94/warc/CC-MAIN-20190923002147-20190923024147-00521.warc.gz"}
|
https://research.tue.nl/nl/publications/modeling-and-identification-of-uncertain-input-systems
|
# Modeling and identification of uncertain-input systems
Riccardo Sven Risuleo (Corresponding author), Giulio Bottegal, Håkan Hjalmarsson
3 Citaten (Scopus)
## Samenvatting
We present a new class of models, called uncertain-input models, that allows us to treat system-identification problems in which a linear system is subject to a partially unknown input signal. To encode prior information about the input or the linear system, we use Gaussian-process models. We estimate the model from data using the empirical Bayes approach: the hyperparameters that characterize the Gaussian-process models are estimated from the marginal likelihood of the data. We propose an iterative algorithm to find the hyperparameters that relies on the EM method and results in decoupled update steps. Because in the uncertain-input setting neither the marginal likelihood nor the posterior distribution of the unknowns is tractable, we develop an approximation approach based on variational Bayes. As part of the contribution of the paper, we show that this model structure encompasses many classical problems in system identification such as Hammerstein models, blind system identification, and cascaded linear systems. This connection allows us to build a systematic procedure that applies effectively to all the aforementioned problems, as shown in the numerical simulations presented in the paper.
Originele taal-2 Engels 130-141 12 Automatica 105 https://doi.org/10.1016/j.automatica.2019.03.014 Gepubliceerd - 1 jul 2019
|
{"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": 0.8561440706253052, "perplexity": 939.918602719031}, "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-2021-10/segments/1614178358956.39/warc/CC-MAIN-20210227114444-20210227144444-00535.warc.gz"}
|
http://physics.stackexchange.com/questions/63449/absorption-extinction-formula-of-nanoparticles
|
# Absorption/Extinction formula of nanoparticles
I know the absorption/extinction equations in nanoparticle physics should be: $$Q_{abs}=\frac{1}{2}\mathbf{Re}\int \mathbf{J}_{tot}\cdot\mathbf{E}_{tot}^\ast dV=\frac{\omega}{2}\mathbf{Im}(\epsilon)\int|\mathbf{E}_{tot}|^2dV$$ also, for the extinction, it reads: $$Q_{ext}=\frac{1}{2}\mathbf{Re}\int \mathbf{J}_{tot}\cdot\mathbf{E}_0^\ast dV$$
But I see in some papers people use the following equations: $$Q_{abs}=\frac{\omega}{2}\mathbf{Im}(\mathbf{d}\cdot\mathbf{E}_{inside}^\ast)$$ where $\mathbf{d}$ is the total dipole moment of nanoparticles. Also, for the extinction, it reads: $$Q_{ext}=\frac{\omega}{2}\mathbf{Im}(\mathbf{d}\cdot\mathbf{E}_0^\ast)$$
I failed to derive the two equations. Can anyone give some help? Or, some reference papers would be also very helpful. Thanks a lot for the help.
-
I think the difference between two is that one of them is a spectrum and, in one case the field depends on time and in the other one it depends on frequency. It is only guess, I can be wrong. – freude May 6 '13 at 8:58
No, both the two equations are dependent on frequency, and are the time-averaged results. – Hui Zhang May 6 '13 at 17:20
What is V? How large is it? – freude May 7 '13 at 7:09
V is the total volume of object, and $\int\cdots dV$ is a volume integral. The size of object is usually assumed to be much smaller than the wavelength of incident light. – Hui Zhang May 10 '13 at 15:00
This mistery has an easy answear: in absence of external currents the total current is the current induced by the electric field, which is just the derivative of the nanoparticle polarization. This holds in general in absence of external current:
$$\mathbf{J}_{pol} = \frac{\partial\mathbf{P}}{\partial t}$$
Now in the case of a nanoparticle (or a dielectric/metallic sphere), it is known that the response to an external field is dipole-like. The total electric dipole $\mathbf{d}$ is given by:
$$\mathbf{d} = \int \mathbf{P}\, d\mathbf{r}$$
Now, since the total field inside the sphere $\mathbf{E}_{inside}$ and the exciting field $\mathbf{E}_0$ are both uniform (Attention: the total field outside the sphere is not uniform!), you can write: \begin{align} Q_{abs} &= \frac{1}{2}\mathbf{Re}\int \mathbf{J}_{pol}\cdot \mathbf{E}_{inside}^* = \frac{1}{2}\mathbf{Re}\left\{ \mathbf{E}_{inside}^*\cdot \int \mathbf{J}_{pol}\, d\mathbf{r} \right\}\\ &=\frac{1}{2}\mathbf{Re}\left\{ \mathbf{E}_{inside}^*\cdot \left(\frac{\partial}{\partial t}\int \mathbf{P}_{pol}\, d\mathbf{r} \right)\right\} = \frac{1}{2}\mathbf{Re}\left\{\left(\frac{\partial}{\partial t}\mathbf{d}\right)\cdot\mathbf{E}_{inside}^*\right\} \end{align}
If the external source is time harmonic, then all the time dependences can be assumed to be of the type $e^{-i\omega t}$, thus
$$\partial_t \mathbf{d} = -i\omega \mathbf{d}$$
Substituting into the above equation, you get:
$$Q_{abs} = \frac{1}{2}\mathbf{Re}\{-i\omega \mathbf{d}\cdot\mathbf{E}^*_{inside}\} = \frac{\omega}{2}\mathbf{Im}\{\mathbf{d}\cdot\mathbf{E}^*_{inside}\}$$
and similarly for the $Q_{ext}$.
-
Very helpful, thank you:) – Hui Zhang Nov 13 '13 at 18:23
You're welcome! – Mattia Nov 13 '13 at 18:56
|
{"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": 1, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.974059522151947, "perplexity": 876.7561218662131}, "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-2014-42/segments/1413507443062.21/warc/CC-MAIN-20141017005723-00295-ip-10-16-133-185.ec2.internal.warc.gz"}
|
http://mathforum.org/mathimages/index.php?title=Law_of_Sines&diff=prev&oldid=32243
|
# Law of Sines
(Difference between revisions)
Revision as of 17:46, 19 August 2011 (edit)← Previous diff Current revision (12:14, 20 June 2012) (edit) (undo) Line 267: Line 267: - ________________________________________________________________ +
If the above problem asked to find the radius of the circumcircle of $\vartriangle ABC$, the law of sines could help to find the diameter. If the above problem asked to find the radius of the circumcircle of $\vartriangle ABC$, the law of sines could help to find the diameter.
## Current revision
Law of Sines
Field: Geometry
Image Created By: Richard Scott
Law of Sines
The law of sines is a tool commonly used to help solve arbitrary triangles. It is a formula that relates the sine of a given angle to its opposite side length.
# Basic Description
In any triangle, there is a relationship between the measures of the angles and the lengths of the sides: the largest angle is opposite the longest side, the second-largest angle is opposite the second-longest side, and the smallest angle is opposite the shortest side.
The law of sines is an equation that more precisely expresses this relationship between the angles of a triangle and the length of their opposite sides. The law of sines states that the ratio between a length of one side of a triangle and the sine of its opposite angle is equal for all three sides. Specifically:
Given a triangle with side lengths $a, b, c$ and opposite angles $A, B, C$,
$\frac{a}{\sin A} = \frac{b}{\sin B} = \frac{c}{\sin C}$
The law of sines is used to find all of the lengths of the sides and the angle measures for an arbitrary triangle given only some of this information. This process is called solving a triangle. To use the law of sines in solving triangles, at least three elements of a triangle must be known. Whenever a side length and two angles are given, the law of sines can be used to solve the triangle.
In some cases, the law of sines can provide multiple solutions to a triangle. If two adjacent side lengths are given with one of the opposite angles, the law of sines cannot definitively determine the triangle, but instead offers zero, one, or two possible solutions in what is known as the ambiguous case.
The law of sines does not help with solving a triangle in several cases. With two known side lengths and the measure of the angle between, there is no way to use the law of sines to solve the triangle because no pair of opposite angle measure and side length is provided. The law of sines by itself is also not able to provide solutions when three side lengths are provided. Instead, the law of cosines is often used for solving triangles in these cases.
# A More Mathematical Explanation
## Two Derivations
There are at least two different ways to derive the law of sines: using the area [...]
## Two Derivations
There are at least two different ways to derive the law of sines: using the area formula and using the definition of sine.
### Using Area
The formula for area of a triangle uses the lengths of the base and height. By using these lengths and the angle measures of a triangle, we can derive the law of sines.
A triangle can be oriented so that any one side can be used as the base. Depending on which side is chosen as the base of the triangle, the height may be different. Let $h_{a}$ be the height when the side of length $a$ is the base. When $a$ is the base, $h_{a}$ is the distance from a vertex to the opposite side, such that $h_{a}$ is perpendicular to the side. When $b$ is oriented as the base of the triangle, $h_{b}$ runs perpendicular to side $b$ and is the distance from side $b$ to the vertex $B$.
First, we must determine the height of the triangle for each orientation of the base.
When $b$ is oriented as the base,
$\sin A = \frac{h_{b}}{c}$
$h_{b} = c \sin A$
When $a$ is oriented as the base,
$\sin B = \frac{h_{a}}{c}$
$h_{a} = c \sin B$
In any triangle,
$\text{Area} = \frac{\text{base} \times \text{height}}{2}$
Since the area of the triangle is the same no matter how the triangle is oriented, the area of the triangle with $b$ as the base is the same as the area of the triangle with $a$ as the base.
$\text{Area}_{\text{base} = b} = \text{Area}_{\text{base} = a}$
Substituting the formula for the area of a triangle,
$\frac{b h_{b}}{2} = \frac{a h_{a}}{2}$
Both $h_{b}$ and $h_{a}$ can be written in terms of side lengths $a, b, c$ and angles $A, B, C$ as shown in the "More on Height" section. Therefore, we can substitute ${(c\sin A)}$ for $h_{b}$ and ${(c\sin B)}$ for $h_{a}$, giving us
$\frac{b(c\sin A)}{2} = \frac{a(c\sin B)}{2}$
Multiplying both sides by $2$ and dividing by $c$ gives us
$b \sin A = a \sin B$
Then, rearranging once more gives us our equation in its most common form,
$\frac{a}{\sin A} = \frac{b}{\sin B}$
Since we can orient the base differently and go through the same process with other variables, we know that $\frac{b}{\sin B} = \frac{c}{\sin C}$, so
$\frac{a}{\sin A} = \frac{b}{\sin B} = \frac{c}{\sin C}$
which is the law of sines.
### Using the Definition of Sine
We know that, in a right triangle,
$\sin A =\frac{\text{opposite}}{\text{hypotenuse}}$
Letting $h$ represent height and $a, b$ represent the lengths of the sides opposite $A, B$, respectively, plug in the appropriate measures to solve for $\sin A, \sin B$.
$\sin A = \frac{h}{b}$
Clearing the fractions,
$b \sin A = h$
$\sin B = \frac{h}{a}$
Clearing the fractions,
$a \sin B = h$
Set both equations for $h$ equal to each other to get
$b \sin A = a \sin B$
Divide both sides by $\sin A, \sin B$ for
$\frac{a}{\sin A} = \frac{b}{\sin B}$
Since we can go through the same process using a different angle and different variables, we know that $\frac{b}{\sin B} = \frac{c}{\sin C}$, so
$\frac{a}{\sin A} = \frac{b}{\sin B} = \frac{c}{\sin C}$
## A Geometric Extension
For every triangle, there is some circle for which the vertices of the triangle lay on the circumference. This triangle is known as an inscribed triangle, and the circle is known as the circumcircle or circumscribed circle.
By the extended law of sines,
$\frac{a}{\sin A} = \frac{b}{\sin B} = \frac{c}{\sin C} = 2r$
where $r$ is the radius of the circumcircle.
### Proof
Let there be two inscribed triangles on a circle of radius $r$. Let $\vartriangle ABD$ be a triangle that has a hypotenuse that goes through the center of the circle. Let $\vartriangle ABC$ be an oblique triangle that shares $\overline{AB}$ with $\vartriangle ABD$.
For $\vartriangle ABD$,
$\sin D = \frac{\overline{AB}}{ \ \overline{AD} \ }$
Angle $C$ is equal to angle $D$ because they are both inscribed angles that cut the same arc. According to properties of inscribed angles, two inscribed angles that cut the same arc in circles of the came radius are equal. Since $\angle{C}$ and $\angle{D}$ are the same, so are $\sin C$ and $\sin D$.
Substituting $\sin C$ for $\sin D$ gives us
$\sin C = \frac{\overline{AB}}{ \ \overline{AD} \ }$
Solving for $\overline{AD}$ gives us
$\overline{AD} = \frac{\overline{AB}}{\sin C}$
Since $\overline{AD}$ is the diameter, $\overline{AD} = 2r$
$2r = \frac{\overline{AB}}{\sin C}$
or equivalently,
$2r = \frac{c}{\sin C}$
since $c$ is the length of the side opposite $\angle{C}$.
By the law of sines, we know that
$\frac{c}{\sin C}= \frac{a}{\sin A} = \frac{b}{\sin B}$
and therefore by the transitive property,
$\frac{a}{\sin A} = \frac{b}{\sin B} = \frac{c}{\sin C} = 2r$
## Example Problem
Solve the triangle. Find all of its parts, $\vartriangle ABC$, given $b = 10$, $A = 60^\circ$,$B = 30^\circ$.
### Solution
Since all of the angle measures in a triangle add up to $180^\circ, C = 90^\circ$
$\frac{a}{\sin A} = \frac{b}{\sin B} = \frac{c}{\sin C}$
$\frac{a}{\sin 60^\circ} = \frac{10}{\sin 30^\circ}$
Cross-multiplying gives us
$a \sin 30^\circ = (10) \sin 60^\circ$
Since $\sin 30^\circ= \frac{1}{2}$ and $\sin 60^\circ= \frac{\sqrt{3}}{2}$,
$a \left( \frac{1}{2} \right) = (10) \left( \frac{\sqrt{3}}{2} \right)$
$a = 10 \sqrt{3}$
$\frac{c}{\sin 90^\circ} = \frac{10}{\sin 30^\circ}$
Cross-multiplying gives us
$c \sin 30^\circ = (10) \sin 90^\circ$
Since $\sin 30^\circ= \frac{1}{2}$ and $\sin 90^\circ= 1$,
$c \left( \frac{1}{2} \right) = (10) (1)$
$c = 20$
If the above problem asked to find the radius of the circumcircle of $\vartriangle ABC$, the law of sines could help to find the diameter.
$\frac{a}{\sin A} = \frac{b}{\sin B} = \frac{c}{\sin C} = 2r$
$\frac{b}{\sin B} = 2r$
Substituting the values for $b, B$,
$\frac{10}{\sin 30^\circ} = 2r$
Since $\sin 30^\circ= \frac{1}{2}$,
$\cfrac{10}{\left( \frac{1}{2} \right)} = 2r$
$20 = 2r$
$10 = r$
# Teaching Materials
There are currently no teaching materials for this page. Add teaching materials.
# References
All images were made by the page's author using Adobe Photoshop and Cinderella2.
Have questions about the image or the explanations on this page?
|
{"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": 109, "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": 0.9258325695991516, "perplexity": 208.64455472806543}, "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-2015-32/segments/1438043058631.99/warc/CC-MAIN-20150728002418-00135-ip-10-236-191-2.ec2.internal.warc.gz"}
|
http://math.stackexchange.com/questions/144976/solving-differential-equation
|
# solving Differential Equation
I have the equation below:
$$(t^2 + 1)dx=(x+4)dt$$
Where $x(0) = 3$
I am trying to use separation of variables, and I end up here:
$$\ln(x+4)=\arctan(t)+C$$
Trying to simplify it more:
$$x=-4+\ln(\arctan(t)+C)$$
Is this correct? I think I should use $x(0) = 3$ to find value of the constant, how can I do that?
Thanks
-
From line 2 to line 3 went something wrong. I guess you wanted to exponentiate both sides? – Fabian May 14 '12 at 12:10
@Sean87 I like the writing on the cup (Feel the same way about changing the world) – Kirthi Raman May 14 '12 at 14:01
Good :P but the source is closed ;) – Sean87 May 14 '12 at 15:16
You are right when you got $\ln(x+4)=\arctan(t)+C$. Starting from here, since $e^{\ln x}=x$, we have $$x+4=e^{\ln(x+4)}=e^{\arctan(t)+C}=e^C\cdot e^{\arctan(t)}=C_1e^{\arctan(t)}$$ where $C_1=e^C$. By the initial condition $x(0)=3$, we have $$7=C_1e^{\arctan(0)}=C_1.$$ Therefore, $$x=7e^{\arctan(t)}-4$$ is the solution of the initial value problem.
-
It should be $7 e^{arctan(t)}$ because $x(0)=3$ not $4$. You still have +1 – Kirthi Raman May 14 '12 at 12:36
@Artin: Thanks. I edited it. – Paul May 14 '12 at 12:45
$$\frac{\mathrm{d}x}{x+4} = \frac{\mathrm{d}t}{t^2+1}$$
Integrating both sides
$$\ln (x+4) = arctan(t) + C \tag{1}$$
$x(0) = 3$ implies
$$\ln(7) = C$$
Rewriting $(1)$
\begin{align*} \ln (x+4) &= arctan(t) + \ln(7) \\ \ln (x+4) - \ln (7) &= arctan(t)\\ \ln \frac{x+4}{7} &= arctan(t)\\ \frac{x+4}{7} = e^{arctan(t)}\\ \Rightarrow x = -4 + 7 e^{arctan(t)} \end{align*}
-
For full credit you should probably say why the other possibility $$\ln(-x-4) = \arctan(t)+C$$ is not the one to use. – GEdgar May 14 '12 at 13:28
Yes, of course (Thanks) – Kirthi Raman May 14 '12 at 14:00
$x(0)=3$ means when $t = 0$ , $x(t) = x = 3$ here $x$ is function in $t$
Here you have to find value of $C$
$\log(x + 4) = \arctan(t) + C$
$\log(3 + 4) = \arctan(0) + C$; $C = \log(7)$
Therefore, the solution is $\log(x + 4) = \arctan(t) + \log(7)$
-
Looks better in TeX, doesn't it? Have a look at how I did it, and then you will be able to do it yourself. – Gerry Myerson May 14 '12 at 12:32
To see the code behind the Tex code click on edit link just below the answer. – Tomarinator May 14 '12 at 12:36
@Prasad, also mention that $\log()$ here is to the base $e$ otherwise one can use $\ln()$ – Kirthi Raman May 14 '12 at 12:39
Another way to see the $\TeX$ code is to highlight the expression, right-click (or Mac equivalent), select "Show Math As" and then "TeX Commands". You might copy what you see straight to your edit box and then modify it to suit your needs (after enclosing in \$'s, since the display omits those). – David Lewis May 14 '12 at 12:47
|
{"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": 0.964138388633728, "perplexity": 1394.7247072613113}, "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-2014-23/segments/1404776427481.71/warc/CC-MAIN-20140707234027-00013-ip-10-180-212-248.ec2.internal.warc.gz"}
|
https://hal-mines-paristech.archives-ouvertes.fr/hal-02445970
|
Accéder directement au contenu Accéder directement à la navigation
An Unscented Hound for Working Memory" and the Cognitive Adaptation of User Interfaces
Abstract : An Unscented Hound for Working Memory (AUHWM) is a new framework for the real-time tracking of human Working Memory (WM) that can be used to adapt computer interfaces to users' available cognitive resources. WM is the part of human cognition responsible for the short term storing and handling of information; it can, in stressful situations, under information overload or when suffering from dementia-like diseases, become severely limited, possibly leading to poor decision making. Our preliminary results suggest that AUHWM can provide a precise and timely assessment of WM capacity, so that the cognitive load a specific task imposes on users can be adapted, e.g., at the User Interface (UI) level. AUHWM is based on a low-level stochastic discrete model of human WM dynamics, implemented as a Gradient-Boosting-derived deterministic algorithm that simulates users' oblivion. AUHWM also performs Unscented Kalman filtering to track users' WM-specific parameters in real time, thus providing a dynamic assessment of their cognitive resources. Our approach has been tested and validated using data collected from Match$^2$s, a visual memory game played by 18 users in another study. Going beyond real-time WM tracking, AUHWM is intended to also be used for WM prediction, paving the way to the adaptation of tasks and their UIs in real time as a function of users' cognitive abilities; we detail an example of such an adapted system, and provide experimental evidence this approach could lead to future enhanced WM-adapted UIs.
Type de document :
Communication dans un congrès
Domaine :
https://hal-mines-paristech.archives-ouvertes.fr/hal-02445970
Contributeur : Claire Medrala <>
Soumis le : lundi 20 janvier 2020 - 15:08:57
Dernière modification le : mercredi 14 octobre 2020 - 03:52:20
Citation
Bruno Massoni Sguerra, Pierre Jouvelot. An Unscented Hound for Working Memory" and the Cognitive Adaptation of User Interfaces. the 27th ACM Conference, Jun 2019, Larnaca, France. pp.78-85, ⟨10.1145/3320435.3320443⟩. ⟨hal-02445970⟩
Métriques
Consultations de la notice
|
{"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": 0.18071362376213074, "perplexity": 5877.001833549171}, "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-2020-50/segments/1606141182794.28/warc/CC-MAIN-20201125125427-20201125155427-00315.warc.gz"}
|
https://zbmath.org/?q=ci%3A0886.35043
|
×
# zbMATH — the first resource for mathematics
On a nonlinear coupled system with internal damping. (English) Zbl 0962.35002
This paper studies an initial-boundary value problem for the following coupled hyperbolic-parabolic system: $u_{tt}-\mu\Delta u+\sum_{i=1}^n{\partial\theta\over \partial x_i} +\gamma |u|^\rho u =0, \quad \theta_t -\Delta\theta +\sum^n_{i=1} {\partial^2 u\over\partial t\partial x_i} =0,\quad \text{in }\Omega\times (0,T),$ together with Dirichlet boundary conditions for both $$u$$ and $$\theta$$, and prescribed initial data, where $$\Omega\in \mathbb{R}^n$$ is a smooth bounded domain, $$\mu$$ is a positive function of $$t$$, $$\gamma$$ and $$\rho$$ are positive constants. The case of $$\gamma =0$$ has been investigated by H. R. Clark, L. P. San Gil Jutuca and M. Milla Miranda [Electron. J. Differ. Equ. 1998, Paper 4 (1998; Zbl 0886.35043)]. Under the assumption that $$\mu\in W^{1,1}(0,\infty)$$ and $$\mu'\leq 0$$, $$\rho\leq {n\over n-1}$$ for $$n\geq 3$$ and $$\rho$$ is arbitrary but fixed for $$n\leq 2$$, the authors prove the existence and uniqueness of global strong and weak solutions; and moreover, the exponential stability of the total energy associated to the strong and weak solutions is obtained. The main ingredients in the proof are the use of the Galerkin method, energy estimates and Lions-Aubin’s compactness theorem, and the construction of a suitable Lyapunov functional.
##### MSC:
35A05 General existence and uniqueness theorems (PDE) (MSC2000) 35L70 Second-order nonlinear hyperbolic equations 35B40 Asymptotic behavior of solutions to PDEs
Full Text:
|
{"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": 0.8653420209884644, "perplexity": 357.05451826179035}, "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-2021-17/segments/1618039398307.76/warc/CC-MAIN-20210420122023-20210420152023-00384.warc.gz"}
|
https://www.investopedia.com/terms/c/chi-square-statistic.asp
|
## What Is a Chi-Square Statistic?
A chi-square (χ2) statistic is a test that measures how a model compares to actual observed data. The data used in calculating a chi-square statistic must be random, raw, mutually exclusive, drawn from independent variables, and drawn from a large enough sample. For example, the results of tossing a fair coin meet these criteria.
Chi-square tests are often used in hypothesis testing. The chi-square statistic compares the size any discrepancies between the expected results and the actual results, given the size of the sample and the number of variables in the relationship. For these tests, degrees of freedom are utilized to determine if a certain null hypothesis can be rejected based on the total number of variables and samples within the experiment. As with any statistic, the larger the sample size, the more reliable the results.
### Key Takeaways
• A chi-square (χ2) statistic is a measure of the difference between the observed and expected frequencies of the outcomes of a set of events or variables.
• χ2 depends on the size of the difference between actual and observed values, the degrees of freedom, and the samples size.
• χ2 can be used to test whether two variables are related or independent from one another or to test the goodness-of-fit between an observed distribution and a theoretical distribution of frequencies.
## The Formula for Chi-Square Is
\begin{aligned}&\chi^2_c = \sum \frac{(O_i - E_i)^2}{E_i} \\&\textbf{where:}\\&c=\text{Degrees of freedom}\\&O=\text{Observed value(s)}\\&E=\text{Expected value(s)}\end{aligned}
## What Does a Chi-Square Statistic Tell You?
There are two main kinds of chi-square tests: the test of independence, which asks a question of relationship, such as, "Is there a relationship between student sex and course choice?"; and the goodness-of-fit test, which asks something like "How well does the coin in my hand match a theoretically fair coin?"
### Independence
When considering student sex and course choice, a χ2 test for independence could be used. To do this test, the researcher would collect data on the two chosen variables (sex and courses picked) and then compare the frequencies at which male and female students select among the offered classes using the formula given above and a χ2 statistical table.
If there is no relationship between sex and course selection (that is, if they are independent), then the actual frequencies at which male and female students select each offered course should be expected to be approximately equal, or conversely, the proportion of male and female students in any selected course should be approximately equal to the proportion of male and female students in the sample. A χ2 test for independence can tell us how likely it is that random chance can explain any observed difference between the actual frequencies in the data and these theoretical expectations.
### Goodness-of-Fit
χ2 provides a way to test how well a sample of data matches the (known or assumed) characteristics of the larger population that the sample is intended to represent. If the sample data do not fit the expected properties of the population that we are interested in, then we would not want to use this sample to draw conclusions about the larger population.
For example consider an imaginary coin with exactly 50/50 chance of landing heads or tails and a real coin that you toss 100 times. If this real coin has an is fair, then it will also have an equal probability of landing on either side, and the expected result of tossing the coin 100 times is that heads will come up 50 times and tails will come up 50 times. In this case, χ2 can tell us how well the actual results of 100 coin flips compare to the theoretical model that a fair coin will give 50/50 results. The actual toss could come up 50/50, or 60/40, or even 90/10. The farther away the actual results of the 100 tosses is from 50/50, the less good the fit of this set of tosses is to the theoretical expectation of 50/50 and the more likely we might conclude that this coin is not actually a fair coin.
|
{"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 1, "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": 0.8184993267059326, "perplexity": 451.6767575915885}, "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/1606141681209.60/warc/CC-MAIN-20201201170219-20201201200219-00117.warc.gz"}
|
https://www.mapsofworld.com/where-is/tombua.html
|
Maps of World
Current, Credible, Consistent
Search
Select Country Flag
World Map / Where Is / Where is Tombua
# Where is Tombua
Location Maps of Cities in Angola
Last Updated : August 09, 2016
|
{"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": 0.8079175353050232, "perplexity": 28013.555107943794}, "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-2017-39/segments/1505818688940.72/warc/CC-MAIN-20170922112142-20170922132142-00349.warc.gz"}
|
http://fr.mathworks.com/help/matlab/ref/gamma.html?s_tid=gn_loc_drop&requestedDomain=fr.mathworks.com&nocookie=true
|
# Documentation
### This is machine translation
Translated by
Mouse over text to see original. Click the button below to return to the English verison of the page.
# gamma
Gamma function
## Syntax
`Y = gamma(X)`
## Description
`Y = gamma(X)` returns the `gamma` function at the elements of `X`. `X` must be real.
collapse all
### Gamma Function
The `gamma` function is defined by the integral:
`$\Gamma \left(x\right)={\int }_{0}^{\infty }{e}^{-t}{t}^{x-1}dt$`
The `gamma` function interpolates the `factorial` function. For integer `n`:
`gamma(n+1) = n! = prod(1:n)`
### Tall Array Support
This function fully supports tall arrays. For more information, see Tall Arrays.
### Algorithms
The computation of `gamma` is based on algorithms outlined in [1]. Several different minimax rational approximations are used depending upon the value of `A`.
## References
[1] Cody, J., An Overview of Software Development for Special Functions, Lecture Notes in Mathematics, 506, Numerical Analysis Dundee, G. A. Watson (ed.), Springer Verlag, Berlin, 1976.
[2] Abramowitz, M. and I.A. Stegun, Handbook of Mathematical Functions, National Bureau of Standards, Applied Math. Series #55, Dover Publications, 1965, sec. 6.5.
|
{"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": 0.8038971424102783, "perplexity": 4630.580008546294}, "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/1474738661155.56/warc/CC-MAIN-20160924173741-00246-ip-10-143-35-109.ec2.internal.warc.gz"}
|
http://silveiraneto.net/2012/08/30/latex-test/
|
# Latex test
This:
i\hbar\frac{\partial}{\partial t}\left|\Psi(t)\right>=H\left|\Psi(t)\right>
Produce this:
$i\hbar\frac{\partial}{\partial t}\left|\Psi(t)\right>=H\left|\Psi(t)\right>$
If you are seeing a complicated math formula in a image then it worked.
|
{"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": 1, "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": 0.9973765015602112, "perplexity": 4137.485816577721}, "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/1492917120881.99/warc/CC-MAIN-20170423031200-00157-ip-10-145-167-34.ec2.internal.warc.gz"}
|
https://www.mersenneforum.org/showpost.php?s=e8a6c49c6989918a8ae15a77bdca2122&p=126011&postcount=17
|
View Single Post
2008-02-17, 22:18 #17
tnerual
Oct 2006
7·37 Posts
Quote:
Originally Posted by Anonymous Okay, great! Glad to hear it's working.
here is the how to do for kubuntu ... (maybe it will not work but for me it worked)
-Make a text file in your LLRnet folder called "start-llrnet.sh" that contains the following data:
Code:
#!/bin/bash
./llrnet
Save the file and close your text editor. Open up a command window, navigate to your LLRnet folder, and type the command "sudo chmod +x start-llrnet.sh". (enter your root password)
-Type the command "sudo crontab -e". (Make sure you run that command as whatever user you'd like to run LLRnet as.)
-You'll find yourself in a command-line text editor, probably nano. Use the arrow keys to navigate to the bottom of the file, and enter the following:
Code:
@reboot sh /home/yourname/Desktop/LLRNETfolder/start-llrnet.sh
(my llrnet is on my desktop)
-Press Ctrl-X. Press the Y key, then press Enter. You will then be returned to the command prompt.
-You're all set! Repeat for each instance of LLRnet you want to run at bootup.
difference is :
sh ==> bash
sudo before commands
|
{"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": 0.5981199145317078, "perplexity": 8377.02651842681}, "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/1596439735836.89/warc/CC-MAIN-20200803224907-20200804014907-00518.warc.gz"}
|
https://economics.stackexchange.com/questions/27723/how-should-i-rebase-my-gdp
|
# How should I rebase my GDP?
I have a constant GDP data from 1988 to 2009 in constant 1985 prices and GDP data from 2009 to 2017 in constant 2000 prices. My question is how should I rebase my GDP?
Upon searching the web, i don't know if what I understand is right..
Should I just divide Both GDP in constant 2000 price to GDP in 2000 and then then multiply the answer of that to the entire series of 1988 to 2009?
|
{"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": 0.8512524962425232, "perplexity": 760.903482459563}, "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/1568514573173.68/warc/CC-MAIN-20190918003832-20190918025832-00169.warc.gz"}
|
https://www.quantumstudy.com/practice-zone/mcq-probability/
|
# MCQ | Probability
Practice Test-I
1 . Three persons A1, A2 and A3 are to speak at a function along with 5 other persons. If the persons speak in random order, the probability that A1 speaks before A2 and A2 speaks before A3 is
(A) 1/6
(B) 3/5
(C) 3/8
(D) none of these
Ans: (A)
2. Two persons A, and B, have respectively n + 1 and n coins, which they toss simultaneously. Then probability P that A will have more heads than B
(A) P >1/2
(B) P = 1/2
(C) 1/4 < P < 1/2
(D) 0 < P < 1/4
Ans: (B)
3. On a toss of two dice, A throws a total of 5, then the probability that he will throw another 5 before he throws 7, is
(A) 1/9
(B) 1/6
(C) 2/5
(D) 5/36
Ans: (C)
4. One of two events must occur. If the chance of one is of the other, then odd in favor of the other are
(A) 1 : 3
(B) 3 : 1
(C) 2 : 3
(D) none of these
Ans: (D)
5. In a convex polygon of 6 sides two diagonals are selected at random. The probability that they intersect at an interior point of the polygon is
(A)2/5
(B)5/12
(C)7/12
(D)3/5
Ans: (B)
6. A and B are two events such that P(A) = 0.2 and P(A∪B) = 0.7. If A and B are independent events then P(B’) equals
(A) 2/7
(B) 7/9
(C) 3/8
(D) none of these
Ans: (C)
7. A fair coin is tossed 99 times. Let X be the number of times heads occurs. Then P(X=r) is maximum when r is
(A) 49
(B) 52
(C) 51
(D) None of these
Ans: (A)
8. The numbers 1, 2, 3,…, n are arranged in random order. The probability that the digits 1, 2, 3…k (k < n) appear as neighbours in that order is
(A) 1/n!
(B) k!/n!
(C) (n-k)!/n!
(D) None of these
Ans: (D)
9. Entries of a 2 x 2 determinant are chosen from the set {1, 1}. The probability that determinant has zero value is
(A) 1/4
(B) 1/3
(C) 1/2
(D) none of these
Ans: (C)
10. A bag contains 14 balls of two colours, the number of balls of colour being equal, seven balls are drawn at random one by one. The ball in hand is returned to the bag before each new draw. The probability that at least 3 balls of each colour are drawn, is
(A) 1/2
(B) >1/2
(C) < 1/2
(D) none of these
Ans: (A)
11. A business man is expecting two telephone calls. Mr Walia may call any time between 2 p.m and 4 p.m. while Mr Sharma is equally likely to call any time between 2.30 p.m. and 3.15 p.m. The probability that Mr Walia calls before Mr Sharma is
(A) 1/18
(B) 1/6
(C) 1/6
(D) none of these
Ans: (C)
12. Let A, B, C be three events such that A and B are independent and P(C) = 0, then events A, B, C are
(A) independent
(B) pairwise independent but not totally independent
(C) P(A) = P(B) = P(C)
(D) none of these
Ans: (A)
13. In a bag there are 15 red and 5 white balls. Two balls are chosen at random and one is found to be red. The probability that the second one is also red is
(A)12/19
(B)13/19
(C)14/19
(D)15/19
Ans: (C)
14. A die is thrown a fixed number of times. If probability of getting even number 3 times is same as the probability of getting even number 4 times, then probability of getting even number exactly once is
(A) 1/4
(B) 3/128
(C) 5/64
(D) 7/128
Ans: (D)
15. A man is know to speak the truth 3 out if 4 times. He throws a die and reports that it is a six. The probability that it is actually a six is
(A) 3/8
(B) 1/5
(B) 3/4
(D) None of these
Ans: (A)
16. A student appears for test I, II and III. The student is successful if he passes either in test I, II or I, III. The probability of the student passing in test I, II and III are respectively p. q and 1/2. If the probability of the student to be successful is 1/2 then
(A) p = q = 1
(B) p = q = 1/2
(C) p = 1 , q = 0
(D) p = 1, q = 1/2
Ans: (C)
17. Three of six faces of a regular hexagon are chosen at random. The probability that the triangle with three vertices is equilateral equal to
(A)1/2
(B)1/5
(C)1/10
(D)1/20
Ans: (C)
18. A fair coin is tossed repeatedly. If tail appear on 1st four tosses, then the probability of head appearing on 5th toss equals to
(A)1/2
(B)1/32
(C)31/32
(D)1/5
Ans: (A)
19. A number is chosen at random from the numbers 10 to 99. By seeing the number a man will laugh if product of the digits is 12. If he choose three numbers with replacement then the probability that he will laugh at least once is
(A) 1 –(3/5)3
(B) (43/45)3
(C) 1 –(4/25)3
(D) 1 –(43/45)3
Ans: (D)
20. If two events A and B are such that P (A) > 0 and P (B) 1, then P is equal to
(A) 1 – P (A/B)
(B) 1 – P(A’/B)
(C) 1 – P [(AUB)/B’]
(D) P (A/B’)
|
{"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": 0.8039195537567139, "perplexity": 682.7692131538488}, "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/1679296948756.99/warc/CC-MAIN-20230328011555-20230328041555-00004.warc.gz"}
|
https://www.techwhiff.com/issue/hydrates-are-formed-with-compounds-a-ionic-b-covalent--632652
|
# Hydrates are formed with _______ compounds A. ionic B. covalent C. None of these D. metallic
1 answer
###### Question:
Hydrates are formed with _______ compounds
A. ionic
B. covalent
C. None of these
D. metallic
## Answers
2 answers
### Please answer need help for quiz will give brainliest answer
please answer need help for quiz will give brainliest answer...
1 answer
### What are the four great inventions of ancient China?
What are the four great inventions of ancient China?...
1 answer
### Use the value of the activation energy (Ea=1.50×102kJ/mol) and the given rate constant of the reaction at either of the two temperatures to predict the rate constant at 551 K.
Use the value of the activation energy (Ea=1.50×102kJ/mol) and the given rate constant of the reaction at either of the two temperatures to predict the rate constant at 551 K....
1 answer
### The first step in drawing a strategic group map is Multiple choice question. assign firms occupying the same map location to a common strategic group. draw circles around each strategic group that are proportional to the group's share of industry revenues. plot firms on a two-variable map based on the strategic variables. identify the variables based on strategic approaches used in the industry.
The first step in drawing a strategic group map is Multiple choice question. assign firms occupying the same map location to a common strategic group. draw circles around each strategic group that are proportional to the group's share of industry revenues. plot firms on a two-variable map based on t...
1 answer
### How many 1 5 s are in 9?
How many 1 5 s are in 9?...
1 answer
### Help me pleaseeeee????????????????
Help me pleaseeeee????????????????...
1 answer
### A dragster starts from rest and travels 1/4 mi in 8.40 s with constant acceleration. What is its velocity when it crosses the finish line?
A dragster starts from rest and travels 1/4 mi in 8.40 s with constant acceleration. What is its velocity when it crosses the finish line?...
2 answers
### 13. Me gusta pasear por la ciudad. Vamos al centro histórico. A. en autobús B. en coche C.en calle D.a pie
13. Me gusta pasear por la ciudad. Vamos al centro histórico. A. en autobús B. en coche C.en calle D.a pie...
1 answer
### Which are the better statistics to use to compare the team scores? Team A's scores 58 60 62 64 66 68 70 72 74 76 78 80 82 84 86 88 90 92 94 96 98 100 Team B's scores 58 60 62 64 66 68 70 72 74 76 78 80 82 84 86 88 90 92 94 96 98 100 O A. Median and standard deviation O B. Mean and standard deviation O C. Mean and IQR O D. Median and IQR
Which are the better statistics to use to compare the team scores? Team A's scores 58 60 62 64 66 68 70 72 74 76 78 80 82 84 86 88 90 92 94 96 98 100 Team B's scores 58 60 62 64 66 68 70 72 74 76 78 80 82 84 86 88 90 92 94 96 98 100 O A. Median and standard deviation O B. Mean and standard deviation...
2 answers
### Number 6 anyone???plz
Number 6 anyone???plz...
1 answer
### If toenails grow at a rate of 1.62 millimeter per month, how fast do they grow each week? (assume 4 weeks in 1 month)
If toenails grow at a rate of 1.62 millimeter per month, how fast do they grow each week? (assume 4 weeks in 1 month)...
1 answer
### Solve for x. Round your answer to the nearest tenth." X 42 15 Plz gelp
Solve for x. Round your answer to the nearest tenth." X 42 15 Plz gelp...
2 answers
### The average length of the dragon used in the performance is 12 feet. The dragon is divided into 9 sections. How long is each sections
The average length of the dragon used in the performance is 12 feet. The dragon is divided into 9 sections. How long is each sections...
2 answers
### Solve for x zx=5g(2x-c)
Solve for x zx=5g(2x-c)...
1 answer
### (2x+ 2) +(3 - 5x) 4.) (3x3 - 4x4) +(2x + 5x4)
(2x+ 2) +(3 - 5x) 4.) (3x3 - 4x4) +(2x + 5x4)...
1 answer
1 answer
### Why was the Western Russia migration (1800s-1980s) so important? Were there any lasting consequences?
Why was the Western Russia migration (1800s-1980s) so important? Were there any lasting consequences?...
1 answer
### What is the movement of particle in a liquid
What is the movement of particle in a liquid...
2 answers
### Wat is a apple in the water and I can come over tomorrow
Wat is a apple in the water and I can come over tomorrow...
1 answer
### What does aspiration mean?
what does aspiration mean?...
-- 0.009692--
|
{"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": 0.4088304340839386, "perplexity": 2144.672507747193}, "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-2023-14/segments/1679296945242.64/warc/CC-MAIN-20230324020038-20230324050038-00039.warc.gz"}
|
https://www.springer.com/us/book/9783319248967?utm_campaign=bookpage_about_buyonpublisherssite&utm_medium=referral&utm_source=springerlink
|
Save today: Get 40% off titles in Popular Science!
SpringerBriefs in Mathematical Physics
# Effective Evolution Equations from Quantum Dynamics
Authors: Benedikter, Niels, Porta, Marcello, Schlein, Benjamin
Free Preview
eBook $54.99 price for USA in USD • ISBN 978-3-319-24898-1 • Digitally watermarked, DRM-free • Included format: PDF, EPUB • ebooks can be used on all reading devices • Immediate eBook download after purchase Softcover$69.99
price for USA in USD
These notes investigate the time evolution of quantum systems, and in particular the rigorous derivation of effective equations approximating the many-body Schrödinger dynamics in certain physically interesting regimes. The focus is primarily on the derivation of time-dependent effective theories (non-equilibrium question) approximating many-body quantum dynamics. The book is divided into seven sections, the first of which briefly reviews the main properties of many-body quantum systems and their time evolution. Section 2 introduces the mean-field regime for bosonic systems and explains how the many-body dynamics can be approximated in this limit using the Hartree equation. Section 3 presents a method, based on the use of coherent states, for rigorously proving the convergence towards the Hartree dynamics, while the fluctuations around the Hartree equation are considered in Section 4. Section 5 focuses on a discussion of a more subtle regime, in which the many-body evolution can be approximated by means of the nonlinear Gross-Pitaevskii equation. Section 6 addresses fermionic systems (characterized by antisymmetric wave functions); here, the fermionic mean-field regime is naturally linked with a semiclassical regime, and it is proven that the evolution of approximate Slater determinants can be approximated using the nonlinear Hartree-Fock equation. In closing, Section 7 reexamines the same fermionic mean-field regime, but with a focus on mixed quasi-free initial data approximating thermal states at positive temperature.
• Introduction
Pages 1-6
Benedikter, Niels (et al.)
• Mean-Field Regime for Bosonic Systems
Pages 7-16
Benedikter, Niels (et al.)
• Coherent States Approach
Pages 17-29
Benedikter, Niels (et al.)
• Fluctuations Around Hartree Dynamics
Pages 31-36
Benedikter, Niels (et al.)
• The Gross-Pitaevskii Regime
Pages 37-56
Benedikter, Niels (et al.)
eBook $54.99 price for USA in USD • ISBN 978-3-319-24898-1 • Digitally watermarked, DRM-free • Included format: PDF, EPUB • ebooks can be used on all reading devices • Immediate eBook download after purchase Softcover$69.99
price for USA in USD
## Bibliographic Information
Bibliographic Information
Book Title
Effective Evolution Equations from Quantum Dynamics
Authors
Series Title
SpringerBriefs in Mathematical Physics
Series Volume
7
2016
Publisher
Springer International Publishing
The Author(s)
eBook ISBN
978-3-319-24898-1
DOI
10.1007/978-3-319-24898-1
Softcover ISBN
978-3-319-24896-7
Series ISSN
2197-1757
Edition Number
1
Number of Pages
VII, 91
Topics
|
{"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": 0.4626202881336212, "perplexity": 3436.043966695722}, "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-2021-04/segments/1610703499999.6/warc/CC-MAIN-20210116014637-20210116044637-00234.warc.gz"}
|
http://www.zazzle.ca/inverse+tshirts
|
Showing All Results
130 results
Page 1 of 3
Related Searches: treetop spider's web, rearward, backward
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
No matches for
Showing All Results
130 results
Page 1 of 3
|
{"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": 0.8219311237335205, "perplexity": 4484.398101535889}, "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-2013-48/segments/1386164004057/warc/CC-MAIN-20131204133324-00099-ip-10-33-133-15.ec2.internal.warc.gz"}
|
https://vesc-project.com/node/407
|
# Endless mode (as Mellow boards have)
7 posts / 0 new
Oyta
Offline
Last seen: 2 weeks 2 days ago
Joined: 2017-05-24 12:30
Posts: 19
Endless mode (as Mellow boards have)
An low battery / prolonging battery / skate feature request! The Mellow Boards Endless mode is quite nice. It would be great to have this option available. Take a look at their official YouTube-channel that introduces the mode: https://www.youtube.com/watch?v=AWWLP7TwsDU
So how I understand the feature is that as long as the throttle or brake is not activated, the ESC listens to the RPM. In my simple mind without knowing much about the bldc-code, I thought the following logic:
# Pseudo code
// User is not using the remote
If !throttle_active and !brake_active and endless_mode {
// The board is moving forward in less than 25 kmh
If Current_RPM > 0 and Current_RPM < RPM_25_kmh {
// The last measured RPM is bigger than the registered target.
// That means that the user has pushed the board and increased
// the speed or that it is a downhill. Plus 3 is to not update
// current RPM if it just reduced the speed (every 0.1 second).
If Current_RPM > (Target_RPM + 3) {
// Set the new target RPM for which the VESC shall keep for 0.1 second
Target_RPM = Current_RPM
// Reset the timer
Timer = now()
}
// Timer reach threshold - reduce the RPM.
If Timer >= 100 ms {
// Reduced the Target_RPM with a rate of 30 RPM per second
Target_RPM = Target_RPM - 3
// Reset timer
Timer = now()
}
// Give sufficient power to keep the Target_RPM
Give_power( Target_RPM )
}
}
timower
Offline
Last seen: 1 year 1 week ago
Joined: 2017-09-07 23:55
Posts: 2
I tried to implement this as a custom app, but it has a few problems.
One problem is overshoot, when setting the RPM the vesc uses a PID controller to set the current based on the rpm error. Now when someone jumps off the board for example the rpm will overshoot quickly causing the endless mode to continuously accelerate.
Another problem is discriminating between pushing and going down a hill for example, this can be ignored if the user brakes.
But I'm currently searching for a solution to the overshoot problem. So if anyone has any ideas, please tell me
Oyta
Offline
Last seen: 2 weeks 2 days ago
Joined: 2017-05-24 12:30
Posts: 19
Interesting! I am not familiar with the bldc code - it is a lot of reading up on. Do you have your code on github, then I can try to understand your implementation?
Oyta
Offline
Last seen: 2 weeks 2 days ago
Joined: 2017-05-24 12:30
Posts: 19
In the Nunchuck app there is some code to maintain speed while using cruise control. https://github.com/vedderb/bldc/blob/79bfbe62344a29817c5e3ea982a2c27d34c6c881/applications/app_nunchuk.c#L268
So I haven't tested the cruise control, so I do not know what happens if jumping off - will it accelerate or just keep the speed? I would have guessed that the PID keeps the speed, but that is just a guess. I had a quick look at the code and didn't see anything coping with this specific case.
When it comes to downhill or pushing I would say the behavior is equal, so no need to separate those cases. Shouldn't it be the same? I think it is important give a max speed option of this feature. It should be user configurable, but in pushing scenarios I'd say 20 or 25 kmh is enough. But making it user configurable it does not matter what I mean :)
timower
Offline
Last seen: 1 year 1 week ago
Joined: 2017-09-07 23:55
Posts: 2
The cruise control mode does indeed work, it just maintains a set speed. This means that when jumping off the PID controller will try to maintain the speed as best as it can, but will generaly overshoot (even just a very small amount) as it can't respond immediately.
This becomes a problem when implementing endless mode, as my method was to change the set point when the current speed is bigger than the set speed. But when overshooting this cause the setpoint to rise, causing the board to accelerate a little bit causing more overshoot and so on.
Also, driving down a hill would require braking as I can't distinguish between pushing and accelerating due to gravity.
I'm curious how mellow boards handle this (mainly when jumping off the board in endless mode).
Oyta
Offline
Last seen: 2 weeks 2 days ago
Joined: 2017-05-24 12:30
Posts: 19
So I revisit this every now and then - I don't have enough time too really get into VESC programming yet. But it helps to gain some knowledge.
It looks like it is this line which sets the pid:https://github.com/vedderb/bldc/blob/79bfbe62344a29817c5e3ea982a2c27d34c6c881/applications/app_nunchuk.c#L317 I guess this is known to you @timower, but just to get the discussion further.
pid_rpm += (out_val * config.stick_erpm_per_s_in_cc) / ((float)OUTPUT_ITERATION_TIME_MS * 1000.0);
if (pid_rpm > (rpm_filtered + config.stick_erpm_per_s_in_cc)) {
pid_rpm = rpm_filtered + config.stick_erpm_per_s_in_cc;
}
• rpm_filtered: I guess this is the current RPM of the motor?
• pid_rpm is the input RPM value to the PID. This is what we should set, and reduce slowly in Endless Mode. If the problem is overshooting, we should try to set an threshold so avoid that.
• out_val: is this the factor for speed ramping? We can rule that one out for this application.
• config.stick_erpm_per_s_in_cc: max erpm change per second in cruisecontrol mode?
So if what I wrote is correct, we could do something like:
if( rpm_filtered > config.endless_mode_max_rpm ) {
// free roll - no power to motors?
}
else {
pid_rpm = rpm_filtered + config.endless_mode_reduce_number_of_rpm // reduce with negative number to decelerate
}
There must of course be more logic around this, like the pseudo code I wrote in the first post.
But, this cannot be correct, because where would the overshooting occur in this example? There must be some knowledge I don't have that is limiting my answers!
Jfriesen
Offline
Last seen: 1 month 3 weeks ago
Joined: 2017-10-24 22:49
Posts: 2
The key here is oing to be properly tuning the PID controller for speed. You are going to need a damped speed controller that has no overshoot in order to achieve what you want. Increasing the derivative term or decreasing the P and I terms will achieve this.
Jeff
|
{"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": 0.23650161921977997, "perplexity": 2259.7674159116264}, "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-2019-22/segments/1558232255251.1/warc/CC-MAIN-20190520001706-20190520023706-00159.warc.gz"}
|
http://www.physicsforums.com/showthread.php?t=205811
|
# Code for great circle?
by makc
Tags: circle, code
P: 587 "Code"? In what language? All you should really need to do is just copy equation (5) from that page, it should work almost verbatim as code in almost any programming language, just remember that $$cos^{-1}$$ becomes for example "acos" in C.
|
{"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": 0.6876440644264221, "perplexity": 1798.2356788909144}, "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-2014-35/segments/1409535919066.8/warc/CC-MAIN-20140901014519-00121-ip-10-180-136-8.ec2.internal.warc.gz"}
|
https://www.physicsforums.com/threads/need-sum-help-information-theory.227586/
|
# Need sum help (information theory)
1. Apr 8, 2008
need sum help plz:) (information theory)
Hello.
I'm working on an information theory-related problem that involves doing a nasty sum. The problem is this: in a widget factory there is a conveyor belt with N widgets on it, and an unknown fraction $\xi = a/N$ of them are defective. You examine a sample of n widgets and find that a fraction $\eta = b/n$. What is mutual information $I(\eta : \xi)$ between the random variables $\eta$ and $\xi$ ? The idea, i think, is to see how large a sample n you need to take so that the sample defect rate gives you information about the actual defect rate. Let A_a be the event that there are a defective parts in the whole lot and B_b be the event that there are b defective parts in the sample. Then the formula for mutual information is:
$$I (\eta : \xi) = \sum_{a=1}^{N} \sum_{b=1}^{n} P(A_{a}) P(B_{b} | A_{a}) \log_{2} { \frac{P(B_{b} | A_{a}) }{P(B_{b})} }$$
which is always nonnegative. Here's what I've got so far: $P(A_{a}) = 1/N$ by principle of insufficient reason (a could be anything from 1 to N with equal probability), and
$$P(B_{b} | A_{a}) = \frac{ \left( ^{a}_{b} \right) \left( ^{N-a}_{n-b} \right) }{ \left(^{N}_{n} \right) } = \frac{ \left( ^{n}_{b} \right) \left( ^{N-n}_{a-b} \right) }{ \left(^{N}_{a} \right) }$$
$$P(B_{b}) = \sum_{a=1}^{N} P(A_{a}) P(B_{b} | A_{a}) = \sum_{a=1}^{N} \frac{1}{N} \frac { \left( ^{n}_{b} \right) \left( ^{N-n}_{a-b} \right) }{ \left(^{N}_{a} \right) } \approx \int_{0}^{1} \left( ^{n}_{b} \right) x^{b} (1 - x)^{n-b} dx = \frac {\left( ^{n}_{b} \right)}{ \left( ^{n}_{b} \right) (n+1)} = \frac {1}{n+1}$$
if you pretend it is a Riemann sum and assume that $N \gg n$ and $a \gg b$, which I'm not sure is OK to do. I'm guessing the idea is to get some asymptotic formula for the mutual information as N becomes large, but how do you retain the dependence on N in the sum? For instance, if I apply the "large N" approximation for $P(B_{b} | A_{a})$, which is $\left( ^{n}_{b} \right) \left(\frac{a}{N}\right)^{b} \left(1 - \frac{a}{N} \right)^{n-b}$, and do the Riemann sum I get an expression that has no dependence on N and apparently diverges to negative infinity (weird because mutual information is nonnegative).
This is not a homework problem, just a "something to think about" problem I came across in an informal book on information theory.
thanks
|
{"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": 0.8746829628944397, "perplexity": 302.13952116900515}, "config": {"markdown_headings": true, "markdown_code": false, "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-2018-26/segments/1529267863519.49/warc/CC-MAIN-20180620124346-20180620144346-00494.warc.gz"}
|
https://zbmath.org/?q=an%3A0673.15006
|
×
# zbMATH — the first resource for mathematics
Uncoupling the Perron eigenvector problem. (English) Zbl 0673.15006
A method is given to find the unique normalized Perron vector $$\pi$$ satisfying $$A\pi =\rho \pi$$ where A is a nonnegative irreducible $$m\times m$$ matrix with spectral radius $$\rho$$, $$\pi =(\pi_ 1,-\pi_ m)^ T$$ and $$\pi_ 1+...+\pi_ m=1$$. The matrix is uncoupled into two or more smaller matrices $$P_ 1,P_ 2,...,P_ k$$ such that this sequence has the following properties: (1) Each $$P_ i$$ is irreducible and nonnegative and has a unique Perron vector $$\pi^{(i)}$$. (2) Each $$P_ i$$ has the spectral radius $$\rho$$. (3) The Perron vectors $$\pi^{(i)}$$ for $$P_ i$$ can be determined independently. (4) The smaller Perron vectors $$\pi^{(i)}$$ can easily be coupled back together to form the Perron vector $$\pi$$ for A.
Reviewer: B.Ruffer-Beedgen
##### MSC:
15B48 Positive matrices and their generalizations; cones of matrices 15A18 Eigenvalues, singular values, and eigenvectors
Full Text:
##### References:
[1] Berman, A.; Plemmons, R.J., Nonnegative matrices in the mathematical sciences, (1979), Academic New York · Zbl 0484.15016 [2] Courtois, P.J., Decomposability: queueing and computer system applications, (1977), Academic New York · Zbl 0368.68004 [3] Gantmacher, F.R., Matrix theory, Vol. II, (1960), Chelsea New York · Zbl 0085.01001 [4] Johnson, C.R., Row stochastic matrices similar to doubly stochastic matrices, Linear and multilinear algebra, 10, 113-130, (1981) · Zbl 0455.15019 [5] Horn, R.A.; Johnson, C.R., Matrix analysis, (1985), Cambridge U.P New York · Zbl 0576.15001 [6] Meyer, C.D., Stochastic complementation, uncoupling Markov chains, and the Simon-Ando theory of nearly reducible systems, NCSU center res. sci. comp. tech. report 10018701, (1987), To appear in Siam Rev. [7] Simon, H.A.; Ando, A., Aggregation of variables in dynamic systems, Econometrica, 29, 2, 111-138, (1961) · Zbl 0121.15103
This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. It attempts to reflect the references listed in the original paper as accurately as possible without claiming the completeness or perfect precision of the matching.
|
{"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": 0.8531014919281006, "perplexity": 2206.229800870021}, "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-2021-17/segments/1618039490226.78/warc/CC-MAIN-20210420183658-20210420213658-00250.warc.gz"}
|
http://mathhelpforum.com/advanced-statistics/101698-failure-devices-prob.html
|
1. ## Failure devices prob.
There are 30 devices, it is known that 20 of them are failure and 10 are ok. There are chosen 4 of them. What is the probability that the chosen devices are not all of them failure/ok?
res. p = 0.611
OK so I tried finding the prob. that 4 of them are failure. I think it is $p^4=(\frac{2}{3})^4=0.197531.$ So the required prob. must be $p=1-p^4=0.802469$. Is it wrong? hehe obviously the res. is different
2. I like your p value. You should consider the binomial theorem here, it is:
$P(X=k) = \binom{n}{k}p^k(1-p)^{n-k}$
In this case $n = 30$, $p = \frac{2}{3}$ and $k = 4$
now substituting in these values we get
$P(X=4) = \binom{30}{4} \left(\frac{2}{3}\right)^4\left(1- \frac{2}{3}\right)^{30-4}$
Can you finish it from here?
This will be the probabilty that 4 devices fail, I think that is what the question is asking?
3. Originally Posted by pickslides
I like your p value. You should consider the binomial theorem here, it is:
$P(X=k) = \binom{n}{k}p^k(1-p)^{n-k}$
pickslides,
The binomial theorem is not applicable here. These are not independent trials.
The answer for not all failures is $1-\frac{\binom{20}{4}}{\binom{30}{4}}$.
4. Originally Posted by Plato
pickslides,
The binomial theorem is not applicable here. These are not independent trials.
The answer for not all failures is $1-\frac{\binom{20}{4}}{\binom{30}{4}}$.
I tried using binomial but with n=4, and that leaded me to p^4
Ok Plato some explanations would be appreciated, and why it doesn't fit with the result in my book?
5. Originally Posted by pickslides
I like your p value. You should consider the binomial theorem here, it is:
$P(X=k) = \binom{n}{k}p^k(1-p)^{n-k}$
In this case $n = 30$, $p = \frac{2}{3}$ and $k = 4$
now substituting in these values we get
$P(X=4) = \binom{30}{4} \left(\frac{2}{3}\right)^4\left(1- \frac{2}{3}\right)^{30-4}$
Can you finish it from here?
This will be the probabilty that 4 devices fail, I think that is what the question is asking?
No the question is to find the probability that not all of them(4) fail/are ok.
6. Originally Posted by javax
Ok Plato some explanations would be appreciated, and why it doesn't fit with the result in my book?
It is not at all clear what you are asking.
If the question is, "Select four items from thirty of which exactly twenty are defective. What is the probability that not all four are defective nor all four are non-defective"
The probabillity that all are defective is $\frac{\binom{20}{4}}{\binom{30}{4}}$.
The probabillity that all are non-defective is $\frac{\binom{10}{4}}{\binom{30}{4}}$.
Now note that those two are disjoint events.
The probabillity that all are defective OR all are non-defective is $\left(\frac{\binom{20}{4}}{\binom{30}{4}}+\frac{\b inom{10}{4}}{\binom{30}{4}}\right)$.
The probabillity that not all are defective and not all are non-defective is
$1-\left(\frac{\binom{20}{4}}{\binom{30}{4}}+\frac{\b inom{10}{4}}{\binom{30}{4}}\right)$.
7. Originally Posted by Plato
It is not at all clear what you are asking.
If the question is, "Select four items from thirty of which exactly twenty are defective. What is the probability that not all four are defective nor all four are non-defective"
The probabillity that all are defective is $\frac{\binom{20}{4}}{\binom{30}{4}}$.
The probabillity that all are non-defective is $\frac{\binom{10}{4}}{\binom{30}{4}}$.
Now note that those two are disjoint events.
The probabillity that all are defective OR all are non-defective is $\left(\frac{\binom{20}{4}}{\binom{30}{4}}+\frac{\b inom{10}{4}}{\binom{30}{4}}\right)$.
The probabillity that not all are defective and not all are non-defective is
$1-\left(\frac{\binom{20}{4}}{\binom{30}{4}}+\frac{\b inom{10}{4}}{\binom{30}{4}}\right)$.
Mate the question is exactly how you said. Your answer still not fitting the given result but I trust you. Thanks
8. Plato one more question.
As I mentioned I tried to find it using $1-p_1^4*p2^4,$ where $p_1=\frac{2}{3}$ and $p_2=\frac{1}{3}$ which is quite close to your result. Is it ok finding it like this?
9. Originally Posted by javax
Mate the question is exactly how you said. Your answer still not fitting the given result but I trust you.
It may be a matter of translation. We may not be doing the same question.
On the other hand, your textbook may be simply be wrong.
10. "Select four items from thirty of which exactly twenty are defective. What is the probability that not all four are defective nor all four are non-defective"
you fully understood my question. It's ok I believe the given result is wrong (Y)
11. Originally Posted by javax
Plato one more question.
As I mentioned I tried to find it using $1-p_1^4*p2^4,$ where $p_1=\frac{2}{3}$ and $p_2=\frac{1}{3}$ which is quite close to your result. Is it ok finding it like this?
Unless the trials, the events, are independent the binomial formula is not applicable.
Selecting four objects from thirty is in no way independent.
But say we have batch twenty black balls and ten white balls.
We pick a random ball from that collection. Record its color and return it to the batch.
We do that four times. Those outcomes are independent.
|
{"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": 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": 0.8704308867454529, "perplexity": 580.4630361003741}, "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-2017-34/segments/1502886133042.90/warc/CC-MAIN-20170824062820-20170824082820-00205.warc.gz"}
|
https://www.coursehero.com/file/51430413/Lecture-26pdf/
|
Lecture_26.pdf - Spline Interpolation Given(n 1 observations or data pairs(x0 f0(x1 f1(x2 f2 …(xn fn This gives a mesh of nodes ⋯ on the independent
# Lecture_26.pdf - Spline Interpolation Given(n 1...
• Notes
• 28
This preview shows page 1 out of 28 pages.
#### You've reached the end of your free preview.
Want to read all 28 pages?
Unformatted text preview: Spline Interpolation Given: (n + 1) observations or data pairs [(x0, f0), (x1, f1), (x2, f2) … (xn, fn)] This gives a mesh of nodes , , , ⋯ on the independent variable and the corresponding function values as , , ,⋯ Goal: fit an independent polynomial in each interval (between two points) with certain continuity requirements at the nodes. Linear spline: continuity in function values, C0 continuity Quadratic spline: continuity in function values and 1st derivatives, C1 continuity Cubic spline: continuity in function values, 1st and 2nd derivatives, C2 continuity Denote for node i or at xi: functional value fi, first derivative ui, second derivative vi Spline Interpolation: Cubic xi+2, fi+2 xi , f i xi-1, fi-1 qi-1(x) qi(x) qi+1(x) xi+1, fi+1 A cubic polynomial in each interval: (n+1) points, n cubic polynomials, 4n unknowns Available conditions: (n + 1) function values, (n - 1) function continuity, (n - 1) 1st derivative continuity conditions and (n - 1) 2nd derivative continuity conditions, total 4n - 2 conditions. 2 free conditions to be chosen by the user! Spline Interpolation: Cubic Cubic Spline in the interval , : is a set of linear splines. Let us denote the 2nd derivative (v) of the function at the ith node as Therefore: We may write: ℎ 6ℎ and ℎ 6ℎ ℎ 6 ℎ 6 Spline Interpolation: Cubic 6ℎ ℎ 6 ; ℎ 6 ℎ ℎ , 6 ℎ ℎ ℎ 6ℎ ℎ ℎ 6 6 ℎ ℎ ℎ ℎ 6 ℎ 6 ℎ 6 ℎ 6 ℎ We need to estimate (n + 1) unknown vi. We have (n – 1) conditions from the continuity of the first derivative. Spline Interpolation: Cubic 6 ℎ ℎ In eq. 1 , 6 3 ℎ 6 ℎ 6 ℎ 3 ℎ , 1 … . 1 ℎ 3 ℎ 3 ℎ 6 ℎ 3 ℎ 6 ℎ 1, 2, 3, ⋯ ℎ ℎ 6 ℎ 3 6 ℎ ; ℎ 3 ℎ 6 , ℎ 6 ℎ , , , , , ℎ , , , ℎ Spline Interpolation: Cubic , , 1, 2, 3, ⋯ So, (n – 1) equations, (n + 1) unknowns, two conditions have to be provided by the users. They decide the type of cubic splines Natural Spline: 0 Parabolic Runout: and Not-a-knot: ⟹ ⟹ ℎ ℎ ℎ ℎ Periodic: ; and First one comes from the data (if not satisfied, the periodic spline is not appropriate); the next two give the other two equations. 1. Spline Interpolation: Cubic , , 1, 2, 3, ⋯ 1. So, (n – 1) equations, (n + 1) unknowns, two conditions have to be provided by the users. They decide the type of cubic splines Clamped Spline: and 3 ℎ 6 ℎ 6 ℎ ℎ , 6 3 3 6 ℎ ℎ 3 ⟹ 3 ℎ 6 ℎ ⟹ ℎ , β ℎ , , 3 ℎ 6 , ℎ β , Example Problem: Q4 of Tutorial 9 Consider the function exp(x) sampled at points x 0, 0.5, 1.0, 1.5 and 2 Estimate the function value at x = 1.80 by interpolating the function using - (a) natural cubic spline and (b) not-a-knot cubic spline. Calculate the true percentage error for both the splines. Which is the better spline for this problem and why? Solution: Posted online along with Tutorial 9 solutions Example Problem: Heat Transfer in Lake Lakes in temperate zone can become thermally stratified during the summer. As depicted below, warm, buoyant water near the surface overlies colder, denser bottom water. Such stratification effectively divides the lake into two layers: the epilimnion and the hypolimnion separated by a plane called the thermocline. Temperature (oC) 0.0 0 Depth, z(m) 5 10 15 20 25 30 5.0 10.0 15.0 20.0 25.0 z (m) 0 2.3 4.9 9.1 13.7 18.3 22.9 27.2 o T( C) 22.8 22.8 22.8 22.6 13.9 11.7 11.1 11.1 Example Problem: Heat Transfer in Lake The location of the thermocline can be defined as the inflection point of the T-z curve; i.e. where = 0. It is also the point at which the absolute value of the first derivative or gradient is maximum. Use cubic splines to determine the thermocline depth of this lake. Also use splines to determine the value of the gradient at the thermocline. Spline Interpolation: Using Local Coordinate ∈ , in , → ∈ 0, 1 → in 0, 1 At each node i, we denote the following: Location: xi Functional value: fi Intervals: ℎ and ℎ Derivatives: First derivative ui and the 2nd derivative vi Transformations: 1 ℎ 1 ℎ ⟹ 1 ℎ 1 ℎ Spline Interpolation: Using Local Coordinate C0 – Continuity: 1 C1 – Continuity: 1 1 ℎ C2 – Continuity: 1 1 ℎ 0 1 0 ℎ 1 0 ℎ Linear and Quadratic Splines: Local Coordinate Linear Spline: C0 – Continuous ⇒ 0 , ⟹ 1 , Quadratic Spline: C1 – Continuous ⇒ 0 , 1 Using the definition of ui: 1 0 ⇒ ℎ , ℎ ℎ ℎ , ℎ Using C1 – Continuity: 1 1 ℎ 1 0 ℎ ⇒ 2 , Cubic Spline: Using Local Coordinate Cubic Spline: C2 – Continuous Using C0 – Continuity: 0 , 1 Now we have two options: Option 1: Using the 1st derivative ui as unknown and C2 – Continuity to estimate them Option 2: Using the 2nd derivative vi as unknown and C1 – Continuity to estimate them Cubic Spline: Using Local Coordinates Option 1: Using the 1st derivative ui as unknown and C2 – Continuity to estimate them , 1 1 0 ; 1 ℎ ℎ ℎ ℎ ℎ 3 , Using C2 – Continuity: 1 ℎ ℎ 2 ℎ 1 ℎ 3 2 ℎ 2 , 2 1 6 2 0 ⇒ ℎ ℎ ℎ 3ℎ , 1, 2, 3, ⋯ 1 2 ℎ 3ℎ , Using the two other conditions, one may obtain similar splines of different types! Cubic Spline: Using Local Coordinates Natural Spline: 0 ℎ 2 ℎ 6ℎ 2 0; 1 ℎ 2 , 3 , 0 ℎ 3 , 6 2 0 0 ℎ 2ℎ 2 3 , 2 2 3 , Clamped Spline: and β Parabolic Runout: 0 ℎ 0 ℎ ℎ 1 and 2 6 2 ⟹ ⟹ ℎ ℎ ℎ 2 6 1 2 ⟹ ⟹ ℎ ℎ 2 , 2 , 0 Cubic Spline: Using Local Coordinates Not-a-knot: ; ⟹ ⟹ ℎ ℎ ℎ ℎ Periodic: and First one comes from the data (if not satisfied, the periodic spline is not appropriate); the next two give the other two equations. Formulation of these two is left as homework! Cubic Spline: Using Local Coordinates Option 2: Using the 2nd derivative vi as unknown and C1 – Continuity to estimate them 1 0 ℎ ℎ 6 , 2 ; ℎ ; Using C1 – Continuity: 1 ℎ ℎ 1 2 ℎ 1 6 2 1 ℎ ℎ ℎ ℎ , 6 1 3 2 0 ⇒ ℎ ℎ ℎ ℎ 6 , 1, 2, 3, ⋯ 1 2 ℎ 6 , This is the same equation that was obtained using Lagrange polynomials! Boundary conditions are also the same! ESO 208A: Computational Methods in Engineering Numerical Differentiation Abhas Singh Department of Civil Engineering IIT Kanpur Acknowledgements: Profs. Saumyen Guha and Shivam Tripathi (CE) Numerical Differentiation Let us compute dy/dx or df/dx at node i Denote the difference operators: ∆ Numerical Differentiation: Finite Difference Approximate the function between , as: ∆ ∆ Forward Difference: ∆ Approximate the function between ∆ ∆ , as: Backward Difference: Numerical Differentiation: Finite Difference Approximate the function between three points: , , ∆ ∆ ∆ ∆ Now, evaluate df/dx at x = xi: ∆ ∆ ∆ ∆ ∆ ∆ Numerical Differentiation: Finite Difference Central Difference: ∆ ∆ ∆ ∆ ∆ ∆ For regular or uniform grid: Let us assume regular grid with a mesh size of h Numerical Differentiation: Finite Difference Approximate the function between three points: 2ℎ ℎ 2ℎ , , Now, evaluate central difference approximations of df/dx and d2f/dx2 at x = xi: 2ℎ ℎ 2ℎ 2 ℎ 2ℎ Numerical Differentiation: Finite Difference Similarly, one can approximate the function between and obtain the forward three points difference expressions of the first and second derivatives at x = xi as follows: This is left for homework practice! Numerical Differentiation: Finite Difference Similarly, one can approximate the function between and obtain the backward three points difference expressions of the first and second derivatives at x = xi as follows: This is left for homework practice! Numerical Differentiation: Finite Difference Accuracy: How accurate is the numerical differentiation scheme with respect to the TRUE differentiation? Truncation Error analysis Modified Wave Number, Amplitude Error and Phase Error analysis for periodic functions Recall: True Value (a) = Approximate Value + Error (ε) Consistency: A numerical expression for differentiation or a numerical differentiation scheme is consistent if it converges to the TRUE differentiation as h → 0. ...
View Full Document
• Fall '19
### What students are saying
• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.
Kiran Temple University Fox School of Business ‘17, Course Hero Intern
• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.
Dana University of Pennsylvania ‘17, Course Hero Intern
• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.
Jill Tulane University ‘16, Course Hero Intern
|
{"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": 0.8606729507446289, "perplexity": 2588.255444510591}, "config": {"markdown_headings": true, "markdown_code": false, "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-2020-05/segments/1579250606269.37/warc/CC-MAIN-20200122012204-20200122041204-00555.warc.gz"}
|
https://www.beatthegmat.com/gmat-math-f5.html?sid=61724f202b1315ff4c15f45098856348
|
GMAT Math
• Forum
Topics
Posts
Last post
Topics
POSTS
Last post
OFFICIAL GUIDE QUESTION LIBRARY
by beatthegmat »
Join the discussion as you work through your Official Guide and gain...
1
Last post by juliagilbert
Thu Jun 02, 2022 6:06 pm
Papgust's GMAT MATH FLASHCARDS directory
by papgust »
Greetings GMAT Aspirants! I spoke to Eric whether i could share my...
146
Last post by bishwa_science
Thu Sep 10, 2020 9:51 am
Help with Q!!
by hectgarza »
Hey there So I just started studying for the Q section of the test...
2
Last post by Andrew9202
Sun Mar 26, 2023 3:58 am
***The GMAT is CHANGING in late 2023 to the GMAT Focus Edition***
by beatthegmat »
Dear All GMAT students, Earlier this month, GMAC announced that the...
0
Last post by beatthegmat
Mon Mar 13, 2023 8:22 pm
Need statistics Homework help?
by thomasw1981 »
Where I can find best tutor for assisting me doing assignments,...
3
Last post by raidamaisa
Thu Feb 16, 2023 11:28 pm
How is the GMAT scored?
by AkankshaBlahblah »
Hi- I wrote my GMAT a couple of days back as a second attempt. After...
2
Last post by [email protected]
Sat Dec 17, 2022 12:23 pm
Need help choosing study material to learn basics of Quant
by Ckapoor0402 »
I have recently started studying for the GMAT .Currently Im reading...
6
Last post by yinaje2912
Sun Dec 04, 2022 9:06 pm
Quant- Numbers Problem
by Neellkanth »
Given that: 4m+n=20; and |n|≤20 How many ordered pairs (m,n) exist...
3
Last post by [email protected]
Tue Jul 12, 2022 1:23 am
GMAT Prep Practice Test Quant Questions #3
by simpm14 »
Just finished my first GMAC Practice Test and am Trying to figure out...
5
Last post by [email protected]
Mon Jun 20, 2022 3:33 am
DS: Coordinates
by haidgmat »
In the xy-plane, at what two points does the graph of y=(x+a)(x+b)...
4
Last post by [email protected]
Mon Jun 20, 2022 3:26 am
Data Sufficiency
by deep319933 »
x is a 4-digit positive integer whose digits are all the integer n...
3
Last post by [email protected]
Mon Jun 20, 2022 3:17 am
Problem Solving Question
by Saup »
If 0<r<1<s<2, which of the following must be less than 1?...
5
Last post by [email protected]
Mon Jun 20, 2022 3:09 am
Data Sufficiency
by DAM1997 »
If y is greater than 110 percent of x, is y greater than 75 ? (1) x...
1
Last post by [email protected]
Mon Jun 20, 2022 2:50 am
Practice Quant problem
by myspecialtie »
I'm having difficulty figuring out the solution to this problem from...
4
Last post by [email protected]
Fri Jun 17, 2022 11:37 am
math
by arbre »
Hi, the general rule is: adding a to the numerator and b to the...
0
Last post by arbre
Mon Jun 06, 2022 11:41 pm
A large ship moving at 14 mph in the river has an investigator cater swimming beside it
by SherzodAzamov »
A large ship moving at 14 mph in the river has an investigator cater...
2
Last post by GmatPoint
Thu Jun 02, 2022 2:08 am
'Average' problem
by Elena89 »
Sam earned a $2,000 commission on a big sale, raising his average... 5 Last post by GmatPoint Thu Jun 02, 2022 1:53 am Recording: Q51 Lunch With Jeff | Number Properties Webinar by [email protected] » Thank you for joining the Number Properties webinar yesterday. If... 0 Last post by [email protected] Fri May 27, 2022 1:20 pm Short Videos by Experts' Global - GMAT Shots | Quantitative by ExpertsGlobal » Dear All, At Experts' Global, we have developed 180+ GMAT Shots - the... 674 Last post by ExpertsGlobal Thu Feb 17, 2022 10:02 pm Total gmat math by jeff sackmann by RebelWanderer » Hi does anyone has pdf copy of total gmat math by jeff sackam...older... 0 Last post by RebelWanderer Sat Oct 02, 2021 10:19 pm There are 54 drivers in a taxi company by SherzodAzamov » There are 54 drivers and 60 cars in a taxi company. Every day, 15... 1 Last post by JuniorG Mon Sep 27, 2021 8:57 pm Is it okay to mention names of b-school alumni who were colleague? by Catahecassa31 » I'm writing about how the particular school will help me achieve my... 0 Last post by Catahecassa31 Sun Aug 29, 2021 9:28 pm DOUBT IN MANHATTAN QUANT QUESTION by aryan0406 » If x = (9b - 3ab)/(3/a - a/3), what is x? (1) 9ab/(3+a) = 18/5 (2) b... 1 Last post by gmatbyexample Mon Jul 12, 2021 12:01 pm MATH by namokshi » If z=1+1/x where x>1, then z could equal to which of the... 2 Last post by GaryZimmerman Thu Jun 24, 2021 10:31 pm A triangle has side lengths of a, b, and c centimeters. by Amzad Sadik » A triangle has side lengths of a, b, and c centimeters. Does each... 4 Last post by [email protected] Fri Jun 11, 2021 3:43 pm Data sufficiency by Newaz111 » Last year, if Arturo spent a total of$12,000 on his mortgage...
5
Last post by Ian Stewart
Sat Jun 05, 2021 9:21 am
how to use fractional exponents
by khaldrogo »
Just wondering what is the probability of encountering a fractional...
2
Last post by Ian Stewart
Sat Jun 05, 2021 8:11 am
Problem Solving | OG 2021 700 Level
by DAM1997 »
A certain state's drinking water production was 980 million pounds in...
2
Last post by [email protected]
Fri Feb 12, 2021 9:19 am
Data Sufficiency | OG 2021, 700 level
by DAM1997 »
At a certain clothing store, customers who buy 2 shirts pay the...
1
Last post by [email protected]
Wed Dec 09, 2020 6:49 pm
DS
by DAM1997 »
A financial account earned 2% annual interest, compounded daily, for...
0
Last post by DAM1997
Sat Nov 28, 2020 2:38 am
Help with a problem about transformations
by HenryBraxton »
TLDR; When doing the transformation D2, T(3,-2), do you translate or...
2
Last post by elwishtwo
Wed Nov 25, 2020 9:23 am
The only contents of a container are 10 disks that are each numbered with a different positive integer from 1 through 10
by mensanumber »
The only contents of a container are 10 disks that are each numbered...
0
Last post by mensanumber
Sun Nov 22, 2020 5:09 pm
Job Scope after Master in Corporate Finance from Henley Business School
by Akshat2000 »
Can someone let me know what'e job scope after doing a Master's in...
3
Last post by GurbaniKaurSuri
Sun Nov 08, 2020 11:41 pm
How to Solve: Box and Whisker Plot
by brushmyquant »
Hi All, I have recently posted a video on Box and Whisker Plot...
3
Last post by [email protected]
Sun Nov 08, 2020 12:27 pm
Geometry
by VenugopalGurram »
In the figure below AB=BC=CD. If the area of the Traingle CDE is...
5
Last post by harrycharlesop
Fri Oct 09, 2020 9:46 pm
PS (600 Level)
by Pranavb1302 »
If r, s and t are numbers, is R=60? (1) The average (arithmetic mean)...
0
Last post by Pranavb1302
Thu Oct 08, 2020 9:52 am
speed time and distance
by shivanshchauhan94 »
Rohan, Shikha's boyfriend, had to pick her from her home for a live...
1
Last post by PhillipZhang87
Fri Sep 18, 2020 5:40 am
Mixture replacement Problems:How to solve effectively and q
by prab.sahi06 »
A milkman mixes 20 litres of water with 80 litres of milk. After...
7
Last post by PhillipZhang87
Tue Sep 15, 2020 3:41 pm
Data sufficiency
by Neha sharma »
M and N are two positive integers and each of them has 20 factors. If...
0
Last post by Neha sharma
Mon Sep 14, 2020 7:23 pm
Statistics - Median and Range Combination Question
by SampathKp »
For 11 distinct positive integers , Median is 90 and Range is 60....
2
Last post by shekki
Tue Aug 18, 2020 1:20 pm
Geometry question
by henilshaht »
I saw this question on Reddit and found it interesting. I think...
2
Last post by ericaconn
Wed Aug 12, 2020 10:44 pm
Divisibility
Which among the following is the smallest 7 digit number that is...
2
Last post by Ignite
Sat Aug 01, 2020 11:30 pm
Percentage
by Harshita567 »
A gas station contaminates petrol with kerosene to earn extra profit,...
3
Last post by Ignite
Sat Aug 01, 2020 11:17 pm
If x is an integer greater than 2, the function f(x)
If x is an integer greater than 2, the function f(x) represents the...
5
Last post by Ignite
Sat Aug 01, 2020 10:11 pm
Each member of a pack of 55 wolves has either brown or blue
by prab.sahi06 »
Each member of a pack of 55 wolves has either brown or blue eyes and...
3
Last post by Ignite
Sat Aug 01, 2020 10:07 pm
percent
by Gurpinder »
a stereo was marked down by 30% and sold for \$84. what was the...
8
Last post by Ignite
Sat Aug 01, 2020 9:30 pm
Absolute Value on the GMAT. Get pumped!
by arosman »
;list=PLnn0cjfKuFzWOzyL5SQFPkt41R6cK-ZPv
0
Last post by arosman
Sat Jul 25, 2020 9:23 am
How to Solve: Inequality Problems - Algebra and Sine Wave/Wavy Method
by brushmyquant »
How to Solve: Inequality Problems Hi All, I have posted a video on...
0
Last post by brushmyquant
Sat Jul 18, 2020 10:40 am
How to Solve: Inequalities (Basic)
by brushmyquant »
How to Solve: Inequalities (Basic) Hi All, I have recently uploaded...
0
Last post by brushmyquant
Sat Jul 18, 2020 10:31 am
How to Solve: Box and Whisker Plot
by brushmyquant »
Hi All, I have also decided to start posting concepts on my Youtube...
2
Last post by brushmyquant
Sat Jul 04, 2020 3:24 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": 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": 0.2639109492301941, "perplexity": 10208.624686492587}, "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-2023-14/segments/1679296948976.45/warc/CC-MAIN-20230329120545-20230329150545-00537.warc.gz"}
|
https://ntanmayee.github.io/articles/2017/09/15/distributed-vs-distributional.html
|
# Distributional Similarity vs Distributed Representation
September 15, 2017
If you are an NLP beginner (like me), then it is common to come across the terms distributional similarity and distributed representation in the context of word embeddings. It’s easy to get confused between the two, or even assume that they mean the same thing. (They do sound very similar to each other.) Distributed representations are usually computed from distributional similarity, but on a conceptual level, they mean different things.
### Distributional Similarity
You shall know a word by the company it keeps.J R Firth, 1957
Distributional similarity is an important hypothesis in linguistics, and the main idea is surprisingly simple - the meaning of a word depends on the words that surround it (its context), and words which have similar contexts must be related to each other.
For example, let’s take the word top, and two sentences -
This purple top will go well with my white skirt.
We took two hours to reach the top of the hill.
Even though the same word top was used in both sentences, they convey different meanings because of the other words that surrounded them.
Now, let’s replace top in the first sentence with shirt. The new sentence - ‘This purple shirt will go well with my white skirt’ is a perfectly sensible sentence. Distributional similarity hypothesizes that top and shirt must be related to each other because they have similar contexts.
The opposite of distributional similarity is denotation. The denotation of a word is the dictionary meaning, or its precise, literal meaning, devoid of emotion, attitude and colour. In some sense, denotation of a word is an absolute meaning of sorts, and distributional similarity is relative to a word’s context.
### Distributed Representation
Before we understand distributed representations, let’s look at its opposite, localist representations. Suppose we have a fixed vocabulary of size $V$, and we want a vector representation of a word from this vocabulary. The localist representation would be to take a vector of length $V$ where $V_i = 1$ where $i$ is the index of the word in some ordering of the vocabulary. For all $V_j$ where $j \neq i$, the entry in the vector would be $0$. (One hot encoding)
For example, if we had a vocabulary {aardvark, apple, …, zebra}, the localist representation of apple would be $\begin{bmatrix}0 & 1 & 0 & \ldots & 0\end{bmatrix}$.
The size of these vectors scales linearly with vocabulary size $V$. Also, there is no in-built notion of similarity between them.
Distributed representations are the opposite of localist representations. They are dense vectors, which are typically much smaller than the vocabulary size, and are designed in such a way that they capture similarity between related words. Word2vec and GloVe are distributed representations for large vocabulary sizes.
### References
Lecture 2 | Word Vector Representations: word2vec. (2017). YouTube. Retrieved 15 September 2017, from https://youtu.be/ERibwqs9p38
Distributional Similarity vs Distributed Representation - September 15, 2017 - Tanmayee Narendra
|
{"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": 0.7473868727684021, "perplexity": 1158.4760687502978}, "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-2021-04/segments/1610703514495.52/warc/CC-MAIN-20210118092350-20210118122350-00364.warc.gz"}
|
https://www.numerade.com/questions/the-point-p1-0-lies-on-the-curve-y-sin-10pi-x-a-if-q-is-the-point-x-sin-10pi-x-find-the-slope-of-the/
|
Meet students taking the same courses as you are!Join a Numerade study group on Discord
# The point $P(1, 0)$ lies on the curve $y = \sin (10\pi /x)$.(a) If $Q$ is the point $(x, \sin (10\pi /x))$, find the slope of the secant line $PQ$ (correct to four decimal places) for $x$ = 2, 1.5, 1.4, 1.3, 1.2, 1.1, 0.5, 0.6, 0.7, 0.8, and 0.9 . Do the slopes appear to be approaching a limit?(b) Use a graph of the curve to explain why the slopes of the secant lines in part (a) are not close to the slope of the tangent line at $P$.(c) By choosing appropriate secant lines, estimate the slope of the tangent line at $P$.
## A. (a) For the curve $y=\sin (10 \pi / x)$ and the point $P(1,0)$$\begin{array}{|c|l|c|}\hline x & Q & m_{P Q} \\\hline 2 & (2,0) & 0 \\1.5 & (1.5,0.8660) & 1.7321 \\1.4 & (1.4,-0.4339) & -1.0847 \\1.3 & (1.3,-0.8230) & -2.7433 \\1.2 & (1.2,0.8660) & 4.3301 \\1.1 & (1.1,-0.2817) & -2.8173 \\\hline\end{array}$$$$\begin{array}{|c|l|c|}\hline x & Q & m_{P Q} \\\hline 0.5 & (0.5,0) & 0 \\0.6 & (0.6,0.8660) & -2.1651 \\0.7 & (0.7,0.7818) & -2.6061 \\0.8 & (0.8,1) & -5 \\0.9 & (0.9,-0.3420) & 3.4202 \\\hline\end{array}$$B. We see that problems with estimation are caused by the frequent oscillations of the graph. The tangent is so steep at$P$that we need to take$x$-values much closer to 1 in order to get accurate estimates of its slope.C.. If we choose$x=1.001,$then the point$Q$is (1.001,-0.0314) and$m p Q \approx-31.3794 .$If$x=0.993,$then$Q$is (0.999,0.0314) and$m p Q=-31.4422 .$The average of these slopes is -31.4108 .So we estimate that the slope of the tangent line at$P\$ is about -31.4
Limits
Derivatives
### Discussion
You must be signed in to discuss.
Lectures
Join Bootcamp
### Video Transcript
this is problem number nine Ah Stewart Calculus eighth edition Section two point one. The problem says the point of P one comma zero flies on the curve y equals sign of ten pie over X Party If Q is the point. Ex comer Sign over ten pie over x. Find the slope of the Secret Line p Q. Correct for tick decimal places for X equals two. One point five, one point four, one point three one point two one point one zero point five seven point six Their point seven they're pointing and zero point name. Let's interests this first part of party first and the slip of the Secret Line will be the same as taking the slope formula, which is M equals Delta y over Delta X. And since we have this function for Q, we first used about. He's given to us to find that always Why for that, Q. And then we use the Reference point p in order to find it. The daughter Raina don't X. So we're going to use X equals two. For example, that's the first X If X equals two. This equation here gives us why. So we're putting it into our signer of ten pine, divided by two that gives a zero. In this case, our delta y zero minus zero aren't up. X is two minutes one Therefore our slope zero divided by one. We continue the exact same calculation as we just discussed for all of the points mentioned. And these air the subsequent results for party find the slope of the Sikh in line for each of these X values. So the answers are the slope is zero. Next to the soap is one point seven three two one. When x is one point five. The slope is negative. One point. Oh, hate for seven. Witness X is one point for him. Soap is Nate. Two point seven for three three for next one point dream. The slope is four point three three. Cho won when x is one point two slippers. Native two point eight one seven three when x is one point one slipped zero when x zero point five soap is negative. Two point one six five one a nexus point six Slope is native to point six zero six one. My next two point seven a sloping thing in a fire the next point eight. And then finally, the slope is three point four to go to the nexus zero point nine. The second part of party asks to the soaps appear to be approaching and limit in previous problems. From this, it's Section two point one. We noticed that as X approaches approached a certain number in this case one we would see a trained trend in the slope approaching a certain number. In this case, we don't see an obvious trend. And we also recall that as we approach one from from higher numbers, we also approach one from the lower numbers, and we should agree on a number usually. But in this case, we see again that there slope it is not a hurry. There's no train and going towards one number exp especially the numbers directly surrounding one, as in one point one and zero point nine, we see that their slopes, or not an agreement at all, and so we should respond is that the slopes do not appear to be approaching a limit then, because the he points closest to one are almost completely different partying. Use a graph of the curve to explain why the slopes of the secret lines and party are not close to the actual slope of the tangent line. So to recall, this is a method. As we approach a certain number here we're approaching X equals one. We usually have slope that it is an agreement more or less. And then we can estimate this slope of the tangent line at that point that we specified. But in this case, we have no agreement. So we need to investigate the craft of the curved to see why that is so. If we look here at this graph of a sign of ten by ten point about my ex Wei have planted to seek in lines the secret line at point nine which has a slope over three point four two in red and then the secret line for X equals one point one that has a slope of negative two point eight one seven three shown here as we can see those slopes to not agree and we can see that the reason for that is that point nine point one point one are not close enough. Two point p, which is here in order for them to have a slope that resembles this tension line on green, which is the actual, I suppose, which is the actual slip of the tension line. That one at Point Pete. And so to answer the question, the reason that the slope of the Secret Line they're not close and did not agrees because they're not close enough to water point nine in one point one or not close enough to estimate the slope of the tangent line and Point Pete for part. See, we will choose appropriate seeking rings to estimate the slope of the Tenderloin and P. So point nine is not close enough. One point one is not close enough. Let's share to pick numbers at her very close to one, both less than one and a little more than one. And what we should see is that we should see that the slope of the sticky lines should be very, very close to this large negative slope for this tension that we see on this craft. So we scroll up a little bit of her spirit chief, and we're going to choose a number that's very, very close, but less than one number that's very, very close, a little more than one. Great. It's on the numbers. We see that the soaps are in agreement and that the slope of this green tension line is I was probably an average of the two. That would be our best estimate. So and we have released two. We should get a soap of a pound negative. Thirty one point four one five nine. So that will be our response. The slope that we estimate is negative. Thirty one point or one. All right? No. And we down there. By choosing them, he can live very close to one.
Limits
Derivatives
Lectures
Join Bootcamp
|
{"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": 0.6539427042007446, "perplexity": 685.8456187707128}, "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/1614178368608.66/warc/CC-MAIN-20210304051942-20210304081942-00531.warc.gz"}
|
http://www.codecogs.com/library/maths/calculus/differential/index.php
|
I have forgotten
• https://me.yahoo.com
# Differential
## Introduction
Differential equations are an powerful mathematical tool that help us understand nature and finance, allowing us to make accurate calculations, including:
• movement of an object
• the collision of two cars
• trajectories of planets
As an example:
Imagine a particle that is projected horizontally (Gravity is neglected):
• Velocity is given by
• Acceleration is
• It is assumed that the drag is proportional to
Applying Newton's second Law: "Force = Mass x Acceleration"
Therefore if we are interested in the distance x
or
If we are interested in time then:
## Definitions
Particular solutions
• When
and
• When
and
Differential Equations which involve only one independent variable are called Ordinary. In these equations x is the independent variable and y is the dependent variable. For example :
Equations which involve two or more independent variables and partial differential coefficients with respect to them are called Partial. For example :
• When
The Laplace equation
### Order
Equations that involve a second differential coefficient but none of higher orders is said to be Second Order.
• When
and
• When
and
• When
For example :
First order
Second order
Third order
### Degree
The degree of an equation is the power of the highest differential coefficient once the equation has been made rational and integral as far as the differential coefficients are concerned. For example :
• When
and
• When
First degree
Second degree
Note that this definition of degree does not require x or y to occur rationally or integrally.
## The Geometrical Meaning Of A Differential Equation
This section presents geometric characteristics of the solution of a differential equation .
### Linear Solution
A linear function is a function such as where
If then
A quadric function is a function such as where
If then
Now consider the equation
Therefore
• If A = 0 the graph is as above.
• If A = 1
• If A = -2
### Exponential Solution
An exponential function is a function such as where
Now consider the following equation:
This can be rearranged as:
The variables have now been separated and :
From which the explicit form is given by:
## The Formation Of Differential Equations By Elimination
If from the following equation we eliminate the arbitrary constant we get the following:
Extending this concept, if we started with n arbitrary constants, we could eliminate them by n differentiations. The result would be a differential equation of the order.
Conversley if we are given a differential equation of the order we can, in general, obtain an equivalent relationship containing no derivatives but n arbitrary constants. This relationship is called "The General Solution"
For Example
where w i aconstant
Integrating with respect to x gives
And so on until
Where A, B, C and E are all arbitrary constants
## The Complete Primitive; Particular Integral; And Singular Solution
The solution of a differential equation containing the full number of arbitrary constants is called "The Complete Primative". Any solution derived from the complete Primitive by giving particular values to these constants is called a "A Particular Integral"
For example
A Particular solution of
is given by
(Obtained by putting A,B,C,E = 0) or
Example:
##### Example - The use of Differential Equations to Solve Problems in Dynamics
Problem
A cricket ball is thrown vertically upwards with a velocity of v ft/sec. The retardation is or . Find the maximum height reached (Y) and the time of flight to the vertex (T).
Prove that the Initial velocity u is given by:
Workings
The acceleration = -kv - g
To find the time of Flight T
thus
When t = 0 v = u
Thus
At the vertex t = T and v = 0 so
i.e.
For Height Y
But when y = 0, v = u so
At the Vertex v = 0
Solution
The flight time is:
Max Height is:
## Differential Equations Which Include Trigonometrical Functions The Right Hand Side
In the following worked examples is usually re-written as . For those unused to this type of trigonometrical manipulation, the following notes should help.
Example:
##### Example - Basic examples .
Problem
Basic trigonometrical examples
Workings
The reference page on Trigonometrical Formulae includes:-
Considering the first equation , this can be re-written as:-
Now if during the solution of a differential equation we arrive at :-
we can compare the right hand side with the right hand side of (5) and we can see that they are of the same form but has been replaced by "3" and by "4". Clearly this can not be correct as the Sine and Cosine can not have a value above unity but if we draw the following right angled triangle.
Values of Sine and Cosine can be obtained which can be put into equation (5)
This can be re-arranged to satisfy the requirements of equation (6)
## Mixed Examples
The next examples will present some mixed differential equations (containing exponential, polynomials, sine, cosine).
Example:
##### Example - Using the lambda example
Problem
Solve
Workings
Using the D operator
Solution
Therefore the General Solution is given by:-
## Section Pages
#### Taylor
Computes the first and second derivatives of a function using the Taylor formula.
double taylor1 (double (*f)(double), double x, double h, double gamma = 1.0)[inline] double taylor2 (double (*f)(double), double x, double h, double gamma = 1.0)[inline]
#### Taylor Table
Computes the first and second derivatives of a function at multiple points.
std::vector taylor1_table (double (*f)(double), std::vector &points, double h, double gamma = 1.0) std::vector taylor2_table (double (*f)(double), std::vector &points, double h, double gamma = 1.0)
#### First Order
First Order Differential Equations with worked examples
#### Linear with Constant Coefficient
A guide to linear equations of second and higher degrees
#### Separable
This section contains worked examples of the type of differential equation which can be solved by integration
#### The D operator
Solving Differential Equations using the D operator
#### Homogeneous
The solution of homogeneous differential equations including the use of the D operator
#### Linear Simultaneous Equations
Linear simultaneous differential equations
#### Partial
An Introduction to Partial Differential Equations
|
{"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": 0.9123048782348633, "perplexity": 1346.6986199335888}, "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/1397609533308.11/warc/CC-MAIN-20140416005213-00038-ip-10-147-4-33.ec2.internal.warc.gz"}
|
http://mathhelpforum.com/calculus/84893-caculate-dervitiv-using-exponential-series.html
|
# Thread: Caculate Dervitiv Using Exponential Series?
1. ## Caculate Dervitiv Using Exponential Series?
Let f(x) = e^x^3
Calculate the 9th derivative f (9)(0) using the exponential
series and Taylor's formula.
Kay am not sure if idid this correect but the series for e^x is
infinte series n=0 to infinty x^n/n! do i just plug in the equation and solve i know its zero but how??
2. Originally Posted by zangestu888
Let f(x) = e^x^3
Calculate the 9th derivative f (9)(0) using the exponential
series and Taylor's formula.
Kay am not sure if idid this correect but the series for e^x is
infinte series n=0 to infinty x^n/n! do i just plug in the equation and solve i know its zero but how??
zero, huh?
$e^x = 1 + x + \frac{x^2}{2!} + \frac{x^3}{3!} + ...$
$e^{x^3} = 1 + x^3 + \frac{x^6}{2!} + \frac{x^9}{3!} + ...$
...
after 9 derivatives, the third term will be a constant equal to
$\frac{9!}{3!} = 60480$.
every subsequent term will have factors of x (which will become 0 when evaluating the 9th derivative at x = 0)
3. Can you please explain what you did? is thier like a shorcut to finding it using the exponential series and Taylor formula
|
{"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": 3, "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": 0.9508364200592041, "perplexity": 2853.914820272189}, "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-2013-48/segments/1387345758566/warc/CC-MAIN-20131218054918-00081-ip-10-33-133-15.ec2.internal.warc.gz"}
|
https://www.kdbfaq.com/category/general/page/2/
|
## How do I use the timer?
If you defined a function called .z.ts, and enable q’s timer with \t n then q will call .z.ts every n milliseconds:
q).z.ts: {[] show .z.T}
q)\t 500
q)07:41:15.147
07:41:15.647
07:41:16.147
07:41:16.647
07:41:17.147
\t 0
q)
As shown above, \t 0 stops the timer.
To set the timer interval, you must give \t a literal integer. What that means is that, if you want to change the timer frequency at runtime (e.g., when building a simple scheduler), the following will not work:
q)i: 500
q).z.ts: {[] show .z.T; system “t i”; i *: 2}
q)\t 500
q)07:46:47.106
07:46:47.606
07:46:48.106
07:46:48.606
\t 0
q)
Notice what happens when we enter \t i at the repl:
q)\t i
0
q)
q)i: 500
q).z.ts: {[] show .z.T; system “t “, string i; i *: 2}
q)\t 500
q)07:59:59.694
08:00:00.195
08:00:01.195
08:00:03.196
\t 0
q)
By passing “t “, string i instead of “t i” to system, the q interpreter sees a literal integer.
One last detail: if you decide you need to delete the definition of .z.ts, you’ll need to use \x.
## What environment variables do I need to know about when kdb starts up?
Here are several environment variables used by q during initialization:
You can read the value of any environment variable with the getenv function:
q)getenv `PATH
“/sw/bin:/sw/sbin:/usr/bin:/bin:/usr/sbin:/sbin:..
q)
|
{"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": 0.8197382092475891, "perplexity": 8842.99108282766}, "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-2019-18/segments/1555578582736.31/warc/CC-MAIN-20190422215211-20190423001211-00317.warc.gz"}
|
https://brilliant.org/problems/hmm-are-you-crazy/
|
# No, Not Possible
Calculus Level 4
$m$ and $n$ are constants. $y$ is defined in terms of $x$ such that
$\large (x+y)^{m+n}=x^my^n.$
Find $\dfrac{dy}{dx}$.
×
|
{"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 12, "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": 0.6360487341880798, "perplexity": 799.4231455241941}, "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-2020-16/segments/1585370491857.4/warc/CC-MAIN-20200328104722-20200328134722-00259.warc.gz"}
|
http://www.ck12.org/geometry/Slope-in-the-Coordinate-Plane/lesson/Slope-in-the-Coordinate-Plane/
|
<meta http-equiv="refresh" content="1; url=/nojavascript/">
# Slope in the Coordinate Plane
## Steepness of a line between two given points.
0%
Progress
Practice Slope in the Coordinate Plane
Progress
0%
Slope in the Coordinate Plane
What if you were given the coordinates of two points? How would you determine the steepness of the line they form? After completing this Concept, you'll be able to find the slope of a line through two points.
### Guidance
Recall from Algebra I that slope is the measure of the steepness of a line. Two points (x1,y1)\begin{align*}(x_1, y_1)\end{align*} and (x2,y2)\begin{align*}(x_2, y_2)\end{align*} have a slope of m=(y2y1)(x2x1)\begin{align*}m = \frac{(y_2-y_1)}{(x_2-x_1)}\end{align*}. You might have also learned slope as riserun\begin{align*}\frac{rise}{run}\end{align*}. This is a great way to remember the formula. Also remember that if an equation is written in slope-intercept form, y=mx+b\begin{align*}y=mx+b\end{align*}, then m\begin{align*}m\end{align*} is always the slope of the line.
Slopes can be positive, negative, zero, or undefined as shown in the pictures below:
Positive:
Negative:
Zero:
Undefined:
#### Example A
What is the slope of the line through (2, 2) and (4, 6)?
Use (2, 2) as (x1,y1)\begin{align*}(x_1, y_1)\end{align*} and (4, 6) as (x2,y2)\begin{align*}(x_2, y_2)\end{align*}.
m=6242=42=2
#### Example B
Find the slope between (-8, 3) and (2, -2).
Use (-8, 3) as (x1,y1)\begin{align*}(x_1, y_1)\end{align*} and (2, -2) as (x2,y2)\begin{align*}(x_2, y_2)\end{align*}.
m=232(8)=510=12
#### Example C
The picture shown is the California Incline, a short road that connects Highway 1 with Santa Monica. The length of the road is 1532 feet and has an elevation of 177 feet. You may assume that the base of this incline is zero feet. Can you find the slope of the California Incline?
In order to find the slope, we need to first find the horizontal distance in the triangle shown. This triangle represents the incline and the elevation. To find the horizontal distance, we need to use the Pythagorean Theorem (a concept you will be introduced to formally in a future lesson), \begin{align*}a^2+b^2 = c^2\end{align*}, where \begin{align*}c\end{align*} is the hypotenuse.
The slope is then \begin{align*}\frac{177}{1521.75}\end{align*}, which is roughly \begin{align*}\frac{3}{25}\end{align*}.
-->
### Guided Practice
1. Find the slope between (-5, -1) and (3, -1).
2. What is the slope of the line through (3, 2) and (3, 6)?
3. Find the slope between (-5, 2) and (3, 4).
1. Use (-5, -1) as \begin{align*}(x_1, y_1)\end{align*} and (3, -1) as \begin{align*}(x_2, y_2)\end{align*}.
The slope of this line is 0, or a horizontal line. Horizontal lines always pass through the \begin{align*}y-\end{align*}axis. The \begin{align*}y-\end{align*}coordinate for both points is -1. So, the equation of this line is \begin{align*}y = -1\end{align*}.
2. Use (3, 2) as \begin{align*}(x_1, y_1)\end{align*} and (3, 6) as \begin{align*}(x_2, y_2)\end{align*}.
The slope of this line is undefined, which means that it is a vertical line. Vertical lines always pass through the \begin{align*}x-\end{align*}axis. The \begin{align*}x-\end{align*}coordinate for both points is 3.
So, the equation of this line is \begin{align*}x = 3\end{align*}.
3. Use (-5, 2) as \begin{align*}(x_1, y_1)\end{align*} and (3, 4) as \begin{align*}(x_2, y_2)\end{align*}.
### Explore More
Find the slope between the two given points.
1. (4, -1) and (-2, -3)
2. (-9, 5) and (-6, 2)
3. (7, 2) and (-7, -2)
4. (-6, 0) and (-1, -10)
5. (1, -2) and (3, 6)
6. (-4, 5) and (-4, -3)
7. (-2, 3) and (-2, -3)
8. (4, 1) and (7, 1)
For 9-10, determine if the statement is true or false.
1. If you know the slope of a line you will know whether it is pointing up or down from left to right.
2. Vertical lines have a slope of zero.
### Vocabulary Language: English Spanish
Slope
Slope
Slope is a measure of the steepness of a line. A line can have positive, negative, zero (horizontal), or undefined (vertical) slope. The slope of a line can be found by calculating “rise over run” or “the change in the $y$ over the change in the $x$.” The symbol for slope is $m$
|
{"extraction_info": {"found_math": true, "script_math_tex": 26, "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": 3, "texerror": 0, "math_score": 0.8991199731826782, "perplexity": 950.3590545047566}, "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/1443736682773.27/warc/CC-MAIN-20151001215802-00182-ip-10-137-6-227.ec2.internal.warc.gz"}
|
http://math.stackexchange.com/questions/30428/a-r-algebra-rightarrow-m-na-cong-m-nr-otimes-a
|
# $A$…$R$-algebra $\Rightarrow M_n(A)\cong M_n(R)\otimes A$
I would like to prove the following statement: if $A$ is an $R$-algebra (for a commutative ring $R$ with $1$), then the $R$-algebras $M_n(A)$ and $M_n(R)\otimes A$ are isomorphic.
By a proposition (Grillet, Abstract Algebra, p. 529) , we have the situation where $\varphi((r_{i,j})_{i,j=1}^n):=(r_{i,j}\cdot 1_A)_{i,j=1}^n$ and $\psi(a):= (\text{matrix with }a\text{ in } 1,1\text{-th entry and }0\text{ elsewhere})$ and $\iota,\kappa$ are canonical. By the proposition, we have a unique algebra homomorphism $\chi$, such that $\chi\circ\iota=\varphi$ (1), $\chi\circ\kappa=\psi$ (2) and $\forall (r_{i,j})\!\otimes\!a: \chi((r_{i,j})\!\otimes\!a)=\varphi((r_{i,j}))\cdot\psi(a)$ (3). Let us prove that $\chi$ is bijective (and therefore an isomorphism).
surjective: By (1) and (2) we know that $im(\varphi)\subseteq im(\chi)$ and $im(\psi)\subseteq im(\chi)$. Let $E_{i,j}$ denote the matrix with $1_R$ at $i,j$-th entry and $0$ elsewhere. Since $E_{i,j}\in im(\varphi)$, $aE_{1,1}\in im(\psi)$ and $E_{i,j}E_{k,l}=\delta_{j,k}E_{i,l}$, it follows that $aE_{i,j}\in im(\chi)$, hence all matrices with entries in $A$ are in $im(\chi)$.
How can I prove that $\chi$ is injective?
-
ugh, help, how can I write diagrams? – Leon Apr 2 '11 at 1:31
## 2 Answers
Instead of showing that $\chi$ is injective, you could attempt to find $\hat\chi$ such that $\hat\chi\circ\chi$ is the identity-maps, then $\chi(u)=\chi(v)$ will imply that $u = \hat\chi\circ \chi(u) = \hat\chi\circ\chi (v) = v$, in other words $\chi$ is injective.
For instance (actually not for instance since it should be the only possibility), consider $$\hat\chi \colon M_n(A) \to M_n(R)\otimes A \colon (c_{ij}) \mapsto \sum_{ij} E_{ij} \otimes c_{ij}.$$
-- Edit: Note that you should take $\psi(a)$ equal to $a\cdot 1$ (which is the diagonal matrix with all $a$'s) for this to work. The problem is that if you do it the way you did, I'm not sure that $im(\psi)$ and $im(\varphi)$ will commute, which they should if you want to apply the universal property. If you take $\psi(a)=a\cdot 1$ they will, because $1$ is central.
-
Excellent, a very good idea. Just one tiny question: why is $\chi\circ\hat{\chi}=id$ already enough and not $\chi\circ\hat{\chi}=id=\hat{\chi}$\circ\chi? – Leon Apr 2 '11 at 15:43
@Leon Lampreet: Actually $\chi\circ\hat\chi$ is not enough, but $\hat\chi\circ\chi$ is. This is because if you know that $\hat\chi\circ \chi = id$ you can proof injectivity of $\chi$ like this: $\chi(u)=\chi(v)\implies\hat\chi(\chi(u))=\hat\chi(\chi(v))\implies u=v$. Now we have that $\chi$ is surjective and injective indeed, therefore $\chi$ is a bijective morphism, as requested. – Myself Apr 2 '11 at 15:50
thank you, it was quite educational for me :) – Leon Apr 2 '11 at 17:17
You can argue more generally that $\hom_R(P,Q)\otimes_RA\cong\hom_A(P\otimes_RA,Q\otimes_RB)$ when $P$ is finitely presented over $R$ and that the isomorphism is compatible with composition of maps, and then take $P=Q=R^n$.
-
(Where A = B?) Is this general case easier then? – Myself Apr 2 '11 at 2:07
@Myself: there are less things that you can do wrong :) – Mariano Suárez-Alvarez Apr 2 '11 at 2:15
|
{"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": 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": 0.9804950952529907, "perplexity": 178.53214544175424}, "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-2016-18/segments/1461861700326.64/warc/CC-MAIN-20160428164140-00124-ip-10-239-7-51.ec2.internal.warc.gz"}
|
https://nrich.maths.org/1063/note
|
### Exploring Wild & Wonderful Number Patterns
EWWNP means Exploring Wild and Wonderful Number Patterns Created by Yourself! Investigate what happens if we create number patterns using some simple rules.
### I'm Eight
Find a great variety of ways of asking questions which make 8.
### Dice and Spinner Numbers
If you had any number of ordinary dice, what are the possible ways of making their totals 6? What would the product of the dice be each time?
# Oranges and Lemons
### Why do this problem?
This problem lends itself to a systematic approach to trial and improvement. It could be used to extend learners when mass is being taught or revised. Alternatively, it could be used as an exercise in number work. A discussion of the role of the fraction in the problem might be interesting
### Key questions
What is the most a lemon can weigh?
Do you have to have a multiple of $3$ lemons?
Is there more than one possible answer?
How you know you have all the solutions?
### Possible extension
Learners could make a table to show the possible solutions and those which are not possible.
### Possible support
Suggest listing some possibilities.
|
{"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": 0.22287292778491974, "perplexity": 1004.5906823914875}, "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/1432207928078.25/warc/CC-MAIN-20150521113208-00308-ip-10-180-206-219.ec2.internal.warc.gz"}
|
https://www.physicsforums.com/threads/solubility-and-equilibrium-question.592520/
|
# Homework Help: Solubility and Equilibrium question
1. Apr 1, 2012
### TeenieBopper
1. The problem statement, all variables and given/known data
Calculate the molar solubility of Cu(OH)2, Ksp = 2.2 × 10^–20, in 0.87 M NH3. Don't forget to use the complexation reaction Cu2+ + 4 NH3 ⇌ Cu(NH3)42+, K = 5.0 × 10^13.
2. Relevant equations
Ksp=[A]^m^n
Keq=[product]/[reactants]
3. The attempt at a solution
I wasn't sure where to begin. I figured that because Cu reacts with NH3, more of the Cu(OH)2 would "disappear" thus having a higher solubility. So I did an ICE table for Cu2+ + 4 NH3 ⇌ Cu(NH3)4 and set it up as x/(.87-x)^5=5 * 10^13, but the answers were non-real. I'm at a loss for where to begin, now. I know I need to do something with the Cu + NH3 reaction, too (otherwise, why would we even be given that information?), but I don't really know what.
2. Apr 1, 2012
### Staff: Mentor
Try to assume concentration of ammonia doesn't change. Note that OH- concentration is a function of ammonia concentration as well.
|
{"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": 0.9443483948707581, "perplexity": 3312.4896246550334}, "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-2018-34/segments/1534221216718.53/warc/CC-MAIN-20180820160510-20180820180510-00544.warc.gz"}
|
http://www.vallis.org/blogspace/preprints/1206.6538.html
|
## [1206.6538] Nonlinear gravitational self-force. I. Field outside a small body
Date: 27 Jun 2012
Abstract: A small extended body moving through an external spacetime $g_{\alpha\beta}$ creates a metric perturbation $h_{\alpha\beta}$, which forces the body away from geodesic motion in $g_{\alpha\beta}$. The foundations of this effect, called the gravitational self-force, are now well established, but concrete results have mostly been limited to linear order. Accurately modeling the dynamics of compact binaries requires proceeding to nonlinear orders. To that end, I show how to obtain the metric perturbation outside the body at all orders in a class of generalized wave gauges. In a small buffer region surrounding the body, the form of the perturbation can be found analytically as an expansion for small distances $r$ from a representative worldline. Given only a specification of the body's multipole moments, the field obtained in the buffer region suffices to find the metric everywhere outside the body via a numerical puncture scheme. Following this procedure at first and second order, I calculate the field in the buffer region around an arbitrarily structured compact body at sufficiently high order in $r$ to numerically implement a second-order puncture scheme, including effects of the body's spin. I also define $n$th-order (local) generalizations of the Detweiler-Whiting singular and regular fields and show that in a certain sense, the body can be viewed as a skeleton of multipole moments.
#### Jun 28, 2012
1206.6538 (/preprints)
2012-06-28, 22:29
|
{"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": 0.7078109383583069, "perplexity": 715.1943577462652}, "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/1516084892892.86/warc/CC-MAIN-20180124010853-20180124030853-00667.warc.gz"}
|
https://wenchao-ma.github.io/GDINA/reference/ClassRate.html
|
This function evaluates the classification rates for two sets of attribute profiles
ClassRate(att1, att2)
## Arguments
att1 a matrix or data frame of attribute profiles a matrix or data frame of attribute profiles
## Value
a list with the following components:
PCA
the proportion of correctly classified attributes (i.e., attribute level classification rate)
PCV
a vector giving the proportions of correctly classified attribute vectors (i.e., vector level classification rate). The fist element is the proportion of at least one attribute in the vector are correctly identified; the second element is the proportion of at least two attributes in the vector are correctly identified; and so forth. The last element is the proportion of all elements in the vector are correctly identified.
## References
Ma, W., & de la Torre, J. (2020). GDINA: An R Package for Cognitive Diagnosis Modeling. Journal of Statistical Software, 93(14), 1-26.
## Examples
if (FALSE) {
N <- 2000
# model does not matter if item parameter is probability of success
Q <- sim30GDINA$simQ J <- nrow(Q) gs <- matrix(0.1,J,2) set.seed(12345) sim <- simGDINA(N,Q,gs.parm = gs) GDINA.est <- GDINA(sim$dat,Q)
CR <- ClassRate(sim\$attribute,personparm(GDINA.est))
CR
}
|
{"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": 0.5689471960067749, "perplexity": 3014.5265598739065}, "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-2020-34/segments/1596439737050.56/warc/CC-MAIN-20200807000315-20200807030315-00563.warc.gz"}
|
https://fm.mizar.org/1993-4/fm4-1.html
|
Formalized Mathematics (ISSN 0777-4028)
Volume 4, Number 1 (1993): pdf, ps, dvi.
1. Katarzyna Zawadzka. The Product and the Determinant of Matrices with Entries in a Field, Formalized Mathematics 4(1), pages 1-8, 1993. MML Identifier: MATRIX_3
Summary: Concerned with a generalization of concepts introduced in \cite{MATRIX_1.ABS}, i.e. there are introduced the sum and the product of matrices of any dimension of elements of any field.
2. Yuji Sakai, Jaroslaw Kotowicz. Introduction to Theory of Rearrangement, Formalized Mathematics 4(1), pages 9-13, 1993. MML Identifier: REARRAN1
Summary: An introduction to the rearrangement theory for finite functions (e.g. with the finite domain and codomain). The notion of generators and cogenerators of finite sets (equivalent to the order in the language of finite sequences) has been defined. The notion of rearrangement for a function into finite set is presented. Some basic properties of these notions have been proved.
3. Andrzej Trybulec. Many-sorted Sets, Formalized Mathematics 4(1), pages 15-22, 1993. MML Identifier: PBOOLE
Summary: The article deals with parameterized families of sets. When treated in a similar way as sets (due to systematic overloading notation used for sets) they are called many sorted sets. For instance, if $x$ and $X$ are two many-sorted sets (with the same set of indices $I$) then relation $x \in X$ is defined as $\forall_{i \in I} x_i \in X_i$.\par I was prompted by a remark in a paper by Tarlecki and Wirsing: Throughout the paper we deal with many-sorted sets, functions, relations etc. ... We feel free to use any standard set-theoretic notation without explicit use of indices'' \cite[p.~97]{Tar-Wir1}. The aim of this work was to check the feasibility of such approach in Mizar. It works.\par Let us observe some peculiarities: \begin{itemize} \item[-] empty set (i.e. the many sorted set with empty set of indices) belongs to itself (theorem 133), \item[-] we get two different inclusions $X \subseteq Y$ iff $\forall_{i \in I} X_i \subseteq Y_i$ and $X \sqsubseteq Y$ iff $\forall_x x \in X \Rightarrow x \in Y$ equivalent only for sets that yield non empty values. \end{itemize} Therefore the care is advised.
4. Ewa Burakowska. Subalgebras of the Universal Algebra. Lattices of Subalgebras, Formalized Mathematics 4(1), pages 23-27, 1993. MML Identifier: UNIALG_2
Summary: Introduces a definition of a subalgebra of a universal algebra. A notion of similar algebras and basic operations on subalgebras such as a subalgebra generated by a set, the intersection and the sum of two subalgebras were introduced. Some basic facts concerning the above notions have been proved. The article also contains the definition of a lattice of subalgebras of a universal algebra.
5. Bogdan Nowak, Andrzej Trybulec. Hahn-Banach Theorem, Formalized Mathematics 4(1), pages 29-34, 1993. MML Identifier: HAHNBAN
Summary: We prove a version of Hahn-Banach Theorem.
6. Jolanta Kamienska, Jaroslaw Stanislaw Walijewski. Homomorphisms of Lattices, Finite Join and Finite Meet, Formalized Mathematics 4(1), pages 35-40, 1993. MML Identifier: LATTICE4
Summary:
7. Jolanta Kamienska. Representation Theorem for Heyting Lattices, Formalized Mathematics 4(1), pages 41-45, 1993. MML Identifier: OPENLATT
Summary:
8. Jaroslaw Stanislaw Walijewski. Representation Theorem for Boolean Algebras, Formalized Mathematics 4(1), pages 45-50, 1993. MML Identifier: LOPCLSET
Summary:
9. Andrzej Trybulec, Yatsuka Nakamura. Some Remarks on the Simple Concrete Model of Computer, Formalized Mathematics 4(1), pages 51-56, 1993. MML Identifier: AMI_3
Summary: We prove some results on {\bf SCM} needed for the proof of the correctness of Euclid's algorithm. We introduce the following concepts: \begin{itemize} \item[-] starting finite partial state (Start-At$(l)$), then assigns to the instruction counter an instruction location (and consists only of this assignment), \item[-] programmed finite partial state, that consists of the instructions (to be more precise, a finite partial state with the domain consisting of instruction locations). \end{itemize} We define for a total state $s$ what it means that $s$ starts at $l$ (the value of the instruction counter in the state $s$ is $l$) and $s$ halts at $l$ (the halt instruction is assigned to $l$ in the state $s$). Similar notions are defined for finite partial states.
10. Andrzej Trybulec, Yatsuka Nakamura. Euclid's Algorithm, Formalized Mathematics 4(1), pages 57-60, 1993. MML Identifier: AMI_4
Summary: The main goal of the paper is to prove the correctness of the Euclid's algorithm for {\bf SCM}. We define the Euclid's algorithm and describe the natural semantics of it. Eventually we prove that the Euclid's algorithm computes the Euclid's function. Let us observe that the Euclid's function is defined as a function mapping finite partial states to finite partial states of {\bf SCM} rather than pairs of integers to integers.
11. Grzegorz Bancerek, Piotr Rudnicki. Development of Terminology for \bf SCM, Formalized Mathematics 4(1), pages 61-67, 1993. MML Identifier: SCM_1
Summary: We develop a higher level terminology for the {\bf SCM} machine defined by Nakamura and Trybulec in \cite{AMI_1.ABS}. Among numerous technical definitions and lemmas we define a complexity measure of a halting state of {\bf SCM} and a loader for {\bf SCM} for arbitrary finite sequence of instructions. In order to test the introduced terminology we discuss properties of eight shortest halting programs, one for each instruction.
12. Grzegorz Bancerek, Piotr Rudnicki. Two Programs for \bf SCM. Part I -- Preliminaries, Formalized Mathematics 4(1), pages 69-72, 1993. MML Identifier: PRE_FF
Summary: In two articles (this one and \cite{FIB_FUSC.ABS}) we discuss correctness of two short programs for the {\bf SCM} machine: one computes Fibonacci numbers and the other computes the {\em fusc} function of Dijkstra \cite{DIJKSTRA}. The limitations of current Mizar implementation rendered it impossible to present the correctness proofs for the programs in one article. This part is purely technical and contains a number of very specific lemmas about integer division, floor, exponentiation and logarithms. The formal definitions of the Fibonacci sequence and the {\em fusc} function may be of general interest.
13. Grzegorz Bancerek, Piotr Rudnicki. Two Programs for \bf SCM. Part II -- Programs, Formalized Mathematics 4(1), pages 73-75, 1993. MML Identifier: FIB_FUSC
Summary: We prove the correctness of two short programs for the {\bf SCM} machine: one computes Fibonacci numbers and the other computes the {\em fusc} function of Dijkstra \cite{DIJKSTRA}. The formal definitions of these functions can be found in \cite{PRE_FF.ABS}. We prove the total correctness of the programs in two ways: by conducting inductions on computations and inductions on input data. In addition we characterize the concrete complexity of the programs as defined in \cite{SCM_1.ABS}.
14. Grzegorz Bancerek. Joining of Decorated Trees, Formalized Mathematics 4(1), pages 77-82, 1993. MML Identifier: TREES_4
Summary: This is the continuation of the sequence of articles on trees (see \cite{TREES_1.ABS}, \cite{TREES_2.ABS}, \cite{TREES_3.ABS}). The main goal is to introduce joining operations on decorated trees corresponding with operations introduced in \cite{TREES_3.ABS}. We will also introduce the operation of substitution. In the last section we dealt with trees decorated by Cartesian product, i.e. we showed some lemmas on joining operations applied to such trees.
15. Takaya Nishiyama, Yasuho Mizuhara. Binary Arithmetics, Formalized Mathematics 4(1), pages 83-86, 1993. MML Identifier: BINARITH
Summary: Formalizes the basic concepts of binary arithmetic and its related operations. We present the definitions for the following logical operators: 'or' and 'xor' (exclusive or) and include in this article some theorems concerning these operators. We also introduce the concept of an $n$-bit register. Such registers are used in the definition of binary unsigned arithmetic presented in this article. Theorems on the relationships of such concepts to the operations of natural numbers are also given.
16. Pauline N. Kawamoto, Yasushi Fuwa, Yatsuka Nakamura. Basic Concepts for Petri Nets with Boolean Markings, Formalized Mathematics 4(1), pages 87-90, 1993. MML Identifier: BOOLMARK
Summary: Contains basic concepts for Petri nets with Boolean markings and the firability$\slash$firing of single transitions as well as sequences of transitions \cite{Nakamura:5}. The concept of a Boolean marking is introduced as a mapping of a Boolean TRUE$\slash$FALSE to each of the places in a place$\slash$transition net. This simplifies the conventional definitions of the firability and firing of a transition. One note of caution in this article - the definition of firing a transition does not require that the transition be firable. Therefore, it is advisable to check that transitions ARE firable before firing them.
17. Grzegorz Bancerek, Piotr Rudnicki. On Defining Functions on Trees, Formalized Mathematics 4(1), pages 91-101, 1993. MML Identifier: DTCONSTR
Summary: The continuation of the sequence of articles on trees (see \cite{TREES_1.ABS}, \cite{TREES_2.ABS}, \cite{TREES_3.ABS}, \cite{TREES_4.ABS}) and on context-free grammars (\cite{LANG1.ABS}). We define the set of complete parse trees for a given context-free grammar. Next we define the scheme of induction for the set and the scheme of defining functions by induction on the set. For each symbol of a context-free grammar we define the terminal, the pretraversal, and the posttraversal languages. The introduced terminology is tested on the example of Peano naturals.
18. Beata Madras. Product of Family of Universal Algebras, Formalized Mathematics 4(1), pages 103-108, 1993. MML Identifier: PRALG_1
Summary: The product of two algebras, trivial algebra determined by an empty set and product of a family of algebras are defined. Some basic properties are shown.
19. Malgorzata Korolkiewicz. Homomorphisms of Algebras. Quotient Universal Algebra, Formalized Mathematics 4(1), pages 109-113, 1993. MML Identifier: ALG_1
Summary: The first part introduces homomorphisms of universal algebras and their basic properties. The second is concerned with the construction of a quotient universal algebra. The first isomorphism theorem is proved.
20. Beata Perkowska. Free Universal Algebra Construction, Formalized Mathematics 4(1), pages 115-120, 1993. MML Identifier: FREEALG
Summary: A construction of the free universal algebra with fixed signature and a given set of generators.
21. Agnieszka Banachowicz, Anna Winnicka. Complex Sequences, Formalized Mathematics 4(1), pages 121-124, 1993. MML Identifier: COMSEQ_1
Summary: Definitions of complex sequence and operations on sequences (multiplication of sequences and multiplication by a complex number, addition, subtraction, division and absolute value of sequence) are given. We followed \cite{SEQ_1.ABS}.
22. Zbigniew Karno. Maximal Discrete Subspaces of Almost Discrete Topological Spaces, Formalized Mathematics 4(1), pages 125-135, 1993. MML Identifier: TEX_2
Summary: Let $X$ be a topological space and let $D$ be a subset of $X$. $D$ is said to be {\em discrete}\/ provided for every subset $A$ of $X$ such that $A \subseteq D$ there is an open subset $G$ of $X$ such that $A = D \cap G$\/ (comp. e.g., \cite{KURAT:2}). A discrete subset $M$ of $X$ is said to be {\em maximal discrete}\/ provided for every discrete subset $D$ of $X$ if $M \subseteq D$ then $M = D$. A subspace of $X$ is {\em discrete}\/ ({\em maximal discrete}) iff its carrier is discrete (maximal discrete) in $X$.\par Our purpose is to list a number of properties of discrete and maximal discrete sets in Mizar formalism. In particular, we show here that {\em if $D$ is dense and discrete then $D$ is maximal discrete}; moreover, {\em if $D$ is open and maximal discrete then $D$ is dense}. We discuss also the problem of the existence of maximal discrete subsets in a topological space.\par To present the main results we first recall a definition of a class of topological spaces considered herein. A topological space $X$ is called {\em almost discrete}\/ if every open subset of $X$ is closed; equivalently, if every closed subset of $X$ is open. Such spaces were investigated in Mizar formalism in \cite{TDLAT_3.ABS} and \cite{TEX_1.ABS}. We show here that {\em every almost discrete space contains a maximal discrete subspace and every such subspace is a retract of the enveloping space}. Moreover, {\em if $X_{0}$ is a maximal discrete subspace of an almost discrete space $X$ and $r : X \rightarrow X_{0}$ is a continuous retraction, then $r^{-1}(x) = \overline{\{x\}}$ for every point $x$ of $X$ belonging to $X_{0}$}. This fact is a specialization, in the case of almost discrete spaces, of the theorem of M.H. Stone that every topological space can be made into a $T_{0}$-space by suitable identification of points (see \cite{STONE:3}).
23. Zbigniew Karno. On Nowhere and Everywhere Dense Subspaces of Topological Spaces, Formalized Mathematics 4(1), pages 137-146, 1993. MML Identifier: TEX_3
Summary: Let $X$ be a topological space and let $X_{0}$ be a subspace of $X$ with the carrier $A$. $X_{0}$ is called {\em boundary}\/ ({\em dense}) in $X$ if $A$ is boundary (dense), i.e., ${\rm Int}\,A = \emptyset$ ($\overline{A} =$ the carrier of $X$); $X_{0}$ is called {\em nowhere dense}\/ ({\em everywhere dense}) in $X$ if $A$ is nowhere dense (everywhere dense), i.e., ${\rm Int}\,\overline{A} = \emptyset$ ($\overline{{\rm Int}\,A} =$ the carrier of $X$) (see \cite{TOPS_3.ABS} and comp. \cite{KURAT:2}).\par Our purpose is to list, using Mizar formalism, a number of properties of such subspaces, mostly in non-discrete (non-almost-discrete) spaces (comp. \cite{TOPS_3.ABS}). Recall that $X$ is called {\em discrete}\/ if every subset of $X$ is open (closed); $X$ is called {\em almost discrete}\/ if every open subset of $X$ is closed; equivalently, if every closed subset of $X$ is open (see \cite{TDLAT_3.ABS}, \cite{TEX_1.ABS} and comp. \cite{KURAT:2},\cite{KURAT:3}). We have the following characterization of non-discrete spaces: {\em $X$ is non-discrete iff there exists a boundary subspace in $X$}. Hence, {\em $X$ is non-discrete iff there exists a dense proper subspace in $X$}. We have the following analogous characterization of non-almost-discrete spaces: {\em $X$ is non-almost-discrete iff there exists a nowhere dense subspace in $X$}. Hence, {\em $X$ is non-almost-discrete iff there exists an everywhere dense proper subspace in $X$}.\par Note that some interdependencies between boundary, dense, nowhere and everywhere dense subspaces are also indicated. These have the form of observations in the text and they correspond to the existential and to the conditional clusters in the Mizar System. These clusters guarantee the existence and ensure the extension of types supported automatically by the Mizar System.
|
{"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": 0.9810052514076233, "perplexity": 1178.0576352929152}, "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-2021-04/segments/1610703521987.71/warc/CC-MAIN-20210120182259-20210120212259-00429.warc.gz"}
|
https://standards.globalspec.com/std/14376208/ahri-210-240
|
### This is embarrasing...
An error occurred while processing the form. Please try again in a few minutes.
### This is embarrasing...
An error occurred while processing the form. Please try again in a few minutes.
# AHRI 210/240
## Performance Rating of Unitary Air-conditioning & Air-source Heat Pump Equipment
active, Most Current
Organization: AHRI Publication Date: 1 January 2023 Status: active Page Count: 141
##### scope:
This standard applies to factory-made Unitary Air-conditioners and Unitary Air-source Heat Pumps with capacities less than 65,000 Btu/h as defined in Section 3.
Energy Source.
This standard applies only to electrically operated, vapor compression refrigeration systems.
Purpose.
The purpose of this standard is to establish the following for Unitary Air-conditioners and Unitary Air-source Heat Pumps: definitions, classifications, test requirements, rating requirements, operating requirements, minimum data requirements for Published Ratings, marking and nameplate data, and conformance conditions.
Intent.
This standard is intended for the guidance of the industry, including manufacturers, engineers, installers, contractors and users.
Review and Amendment.
This standard is subject to review and amendment as technology advances.
### Document History
AHRI 210/240
January 1, 2023
Performance Rating of Unitary Air-conditioning & Air-source Heat Pump Equipment
This standard applies to factory-made Unitary Air-conditioners and Unitary Air-source Heat Pumps with capacities less than 65,000 Btu/h as defined in Section 3. Energy Source. This standard applies...
January 1, 2017
Performance Rating of Unitary Air-conditioning & Air-source Heat Pump Equipment
This standard applies to factory-made Unitary Air-conditioners and Unitary Air-source Heat Pumps with capacities less than 65,000 Btu/h as defined in Section 3. Energy Source. This standard applies...
January 1, 2008
Performance Rating of Unitary Air-Conditioning & Air-Source Heat Pump Equipment
This standard applies to factory-made Unitary Air-Conditioners and Air-Source Unitary Heat Pumps as defined in Section 3. Energy Source. This standard applies only to electrically operated, vapor...
January 1, 2008
Performance Rating of Unitary Air-Conditioning & Air-Source Heat Pump Equipment
This standard applies to factory-made Unitary Air-Conditioners and Air-Source Unitary Heat Pumps as defined in Section 3. Purpose. The purpose of this standard is to establish, for Unitary...
January 1, 2006
PERFORMANCE RATING OF UNITARY AIR-CONDITIONING AND AIR-SOURCE HEAT PUMP EQUIPMENT
Purpose. The purpose of this standard is to establish, for Unitary Air-Conditioners and Air-Source Unitary Heat Pumps: definitions; classifications; test requirements; rating requirements; minimum...
January 1, 2005
PERFORMANCE RATING OF UNITARY AIR-CONDITIONING AND AIR-SOURCE HEAT PUMP EQUIPMENT
This standard applies to factory-made Unitary Air-Conditioners and Air-Source Unitary Heat Pumps as defined in Section 3. Energy Source. This standard applies only to electrically operated, vapor...
January 1, 2003
Unitary Air-Conditioning and Air-Source Heat Pump Equipment (Best Copy Available)
A description is not available for this item.
January 1, 1994
Unitary Air-Conditioning and Air-Source Heat Pump Equipment
This standard applies to factory-made residential, commercial, and industrial equipment defined in 3.2 and 3.3. Energy Source. This standard applies only to electrically-driven, mechanical...
|
{"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": 0.8866627216339111, "perplexity": 16887.474918078882}, "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-2021-39/segments/1631780055775.1/warc/CC-MAIN-20210917181500-20210917211500-00533.warc.gz"}
|
https://mathyug.com/example-12-find-the-conjugate/
|
# Example 12 Find the conjugate
## Chapter 5 Complex Numbers Class 11 Maths
NCERT Chapter 5 Complex Numbers Example 12 Find the conjugate of {\displaystyle \frac{(3-2i)(2+3i)}{(1+2i)(2-i)} }
03:02
## Question 14 Find the real numbers x and y if (x−iy)(3+5i) is the conjugate of −6−24i
NCERT Miscellaneous Exercise Question 14. Find the real numbers x and y if {\displaystyle (x-iy)(3+5i) } is the conjugate of {\displaystyle -6-24i } .
04:43
## Find the modulus and the arguments of each of the complex numbers in
NCERT Exercise 5.2 Find the modulus and the arguments of each of the complex numbers in Exercises 1 to 2. Question - 1: {\displaystyle z=-1-i \sqrt{3} } .
|
{"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": 0.9235407710075378, "perplexity": 1367.0351467948835}, "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/1679296944452.97/warc/CC-MAIN-20230322211955-20230323001955-00103.warc.gz"}
|
https://nsb.wikidot.com/c-9-2-2-4
|
Structure of Cellulose
• Cellulose contains the basic C-C chains required to manufacture petrochemicals
• Unlike fossil fuels, cellulose is a readily available raw material and the major constituent of biomass (material made entirely or in large part by living organisms), making it a renewable resource.
• Cellulose can be broken down by glucose by acid digestion or through cellulase enzymes, once broken, glucose can be fermented to form ethanol, which is an industrially important solvent, as well as being a useful fuel extender in vehicles.
• Cellulose is biodegradable and can be used to develop biopolymers such as rayon, cellophane and cellulose acetate.
• Ethanol can be further reacted in a dehydration reaction to form ethylene, which is an industrially significant monomer used to manufacture many petrochemicals.
• Ethylene can then be used to form polyethylene or other important monomers such as vinyl chloride and styrene.
• It is the formation of ethanol and ethylene from cellulose that gives it the potential as a raw material in the production of petrochemicals.
• Breaking cellulose by acid digestion or through cellulose enzymes are both time consuming and expensive as it has strong $\beta$-1,4-glycosidic bonds which are difficult to break.
|
{"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": 0.7633181214332581, "perplexity": 5758.904368461484}, "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/1563195524254.28/warc/CC-MAIN-20190715215144-20190716001144-00108.warc.gz"}
|
https://cs.stackexchange.com/questions/97179/how-to-define-the-natural-numbers-as-a-w-type
|
# How to define the natural numbers as a W-type?
I'm having trouble understanding the rules for W-types in type theory as defined here: https://ncatlab.org/nlab/show/W-type#wtypes_in_type_theory
Can someone give an example of how these rules could be used to define a simple W-type such as the natural numbers? What would $A$ and $B$ be in the formation rule for instance?
The formation and introduction rules for W-types, as given on n-cat lab, are:
$$\frac{A:Type\quad x:A⊦B:Type}{(W x:A)B(x):Type}-\text{Formation}$$
$$\frac{a:A\quad t:B(a)\rightarrow W}{sup(a,t):W}-\text{Introduction}$$
You can define the natural numbers by setting $A=Bool$ and $B(a) = \text{if}\; a\; \text{then}\; ⟂\; \text{else}\; Unit$. Where $⟂$ is the empty type and $Unit$ is the unit type.
Zero is then $sup(a,t)$ where $a=true$ and $t: ⟂ \rightarrow Nat = λn. abort(n)$. eg. we use the zero constructor (by choosing $a=true$) and fill in the only possible value of a function from $⟂$ to $Nat$.
The successor of $p$ can be defined as $a=false$, $t:Unit \rightarrow Nat = λx.p$.
|
{"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": 0.9835591316223145, "perplexity": 183.8355146255931}, "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-2019-47/segments/1573496671245.92/warc/CC-MAIN-20191122065327-20191122093327-00364.warc.gz"}
|
http://stats.stackexchange.com/questions/26722/calculate-transition-matrix-markov-in-r
|
# Calculate Transition Matrix (Markov) in R
Is there a way in R (a built-in function) to calculate the transition matrix for a Markov Chain from a set of observations?
For example, taking a data set like the following and calculate the first order transition matrix?
dat<-data.frame(replicate(20,sample(c("A", "B", "C","D"), size = 100, replace=TRUE)))
-
What is this matrix supposed to represent? One run of the Markov chain for each row (or column)? Or...? – cardinal Apr 19 '12 at 0:07
This being 100 samples of state sequences (20 of them). – B_Miner Apr 19 '12 at 0:16
Are you looking for probability estimates or just counts? – cardinal Apr 19 '12 at 0:48
Probability estimates. Using the observed sequences, what is the transition probability matrix (4x4 in this example). – B_Miner Apr 19 '12 at 0:52
## 2 Answers
I am not immediately aware of a "built-in" function (e.g., in base or similar), but we can do this very easily and efficiently in a couple of lines of code.
Here is a function that takes a matrix (not a data frame) as an input and produces either the transition counts (prob=FALSE) or, by default (prob=TRUE), the estimated transition probabilities.
# Function to calculate first-order Markov transition matrix.
# Each *row* corresponds to a single run of the Markov chain
trans.matrix <- function(X, prob=T)
{
tt <- table( c(X[,-ncol(X)]), c(X[,-1]) )
if(prob) tt <- tt / rowSums(tt)
tt
}
If you need to call it on a data frame you can always do
trans.matrix(as.matrix(dat))
If you're looking for some third-party package, then Rseek or the R search site may provide additional resources.
-
+1 There are also several R packages, including HMM and RHMM that might be helpful. – Wayne Apr 19 '12 at 1:43
@Wayne: (+1) I have found the various HMM packages available in R to be very finicky in the past, particularly when it comes to fitting and I never found one I truly liked or trusted. Maybe the situation is better now. I would imagine they would get this right, though. If you know of such a solution, please submit it as an answer; I would be happy to up vote it! – cardinal Apr 19 '12 at 1:49
I tried, but with no success. This problem doesn't involve hidden states and the packages I found don't have any utility functions that would do anything less than full-blown HMM. (As a side note, the dat data frame that the OP gives as an example has columns of data, and do they want a transition matrix per column, or an overall transition matrix or can we just turn the matrix into a vector?) – Wayne Apr 19 '12 at 12:22
@Wayne: (+1) You raise a good point. I have assumed that each row is an independent run of the Markov chain and so we are seeking the transition probability estimates form these chains run in parallel. But, even if this were a chain that, say, wrapped from one end of a row down to the beginning of the next, the estimates would still be quite closer due to the Markov structure. – cardinal Apr 19 '12 at 13:12
@B_Miner: Yes, it does, as long as you can reasonably assume that each customer behaves independently of all others. Such models and many extensions are relatively common in analyzing user behavior, e.g., on repeated visits to a website, etc. – cardinal Apr 19 '12 at 16:34
I have just uploaded a new R package, markovchain, based on S4 programming style. Along with various methods to handle S4 markovchain objects it contains a function to fit a Markov chain from a sequence of states. Have a look at:
library(markovchain)
sequence <- c("a", "b", "a", "a", "a", "a", "b", "a", "b", "a",
"b", "a", "a", "b", "b", "b", "a")
mcFit <- markovchainFit(data=sequence)
It could help.
-
A very nice package! Will you be supporting higher-order Markov Chains? – Wayne Feb 23 '14 at 2:50
I have been asked for higher order Markov chain and another guy is writing some code. If you wish to partecipate in code developing send an email to mantainer address and we can discuss... – Giorgio Spedicato Feb 23 '14 at 21:58
|
{"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": 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": 0.601076602935791, "perplexity": 1068.3469842297632}, "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-2016-26/segments/1466783403508.34/warc/CC-MAIN-20160624155003-00055-ip-10-164-35-72.ec2.internal.warc.gz"}
|
http://link.springer.com/article/10.1007%2FBF01801202
|
, Volume 12, Issue 2, pp 322-339
# Quantum gravity and the structure of scientific revolutions
Rent the article at a discount
Rent now
* Final gross prices may vary according to local VAT.
## Summary
In a case study Kuhn's morphology of scientific revolutions is put to the test in confronting it with the contemporary developments in physics. It is shown in detail, that Kuhn's scheme is not compatible with the situation in physics today.
|
{"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": 0.8221940994262695, "perplexity": 1556.184445240753}, "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-2014-35/segments/1408500831098.94/warc/CC-MAIN-20140820021351-00016-ip-10-180-136-8.ec2.internal.warc.gz"}
|
https://forum.allaboutcircuits.com/threads/need-help-with-magnetic-circuit-mean-path-length.152881/
|
# Need help with magnetic circuit (mean path length)
#### 김찬우 1
Joined Oct 8, 2018
11
ri=3.4cm, ro=40.cm
and the question is calculating the mean core length, and the answer is
but i cant understand how this calculation came out.
i think it should be 2*pi*(r0+ri)/2=pi(r0+ri),, i need explanations for this problem.
thanks
Last edited:
#### wayneh
Joined Sep 9, 2010
16,400
Deriving the answer requires a good application of some calculus skills. Otherwise you have to accept the solution, that the mean circumference depends on the mean radius, which is at least easy to remember.
Oops I missed that the given answer is crap.
Last edited:
#### 김찬우 1
Joined Oct 8, 2018
11
you mean
#### ebp
Joined Feb 8, 2018
2,332
EDIT - made a mess of this the first time; should be OK now
Your equation is correct. If g is zero
le = π(Ro+Ri)
Here's a datasheet for a powdered iron core I've used many times:
micrometalsarnoldpowdercores.com/pdf/T106-52-DataSheet.pdf
Note that the specifications for dimensions are the inner and outer diameters in millimetres and the path length is specified in centimetres. Your equation gives the corrrect path length.
Last edited:
#### 김찬우 1
Joined Oct 8, 2018
11
thanks for the replying. it helped me a lot.
edit - can i ask you one more?
the question says that the iron is of infinite permeability and neglect the effects of magnetic leakage and fringing.
Do this assumption affects the calculation of mean core length?
#### wayneh
Joined Sep 9, 2010
16,400
thanks for the replying. it helped me a lot.
edit - can i ask you one more?
the question says that the iron is of infinite permeability and neglect the effects of magnetic leakage and fringing.
Do this assumption affects the calculation of mean core length?
Nope. If the permeability was not uniform with radius, that could have an effect.
#### MrAl
Joined Jun 17, 2014
7,849
View attachment 161191
ri=3.4cm, ro=40.cm
and the question is calculating the mean core length, and the answer is
View attachment 161193
but i cant understand how this calculation came out.
i think it should be 2*pi*(r0+ri)/2=pi(r0+ri),, i need explanations for this problem.
thanks
Hello,
Hard to verify exactly if you dont give the value of 'g', but they may be implying that g=0.2 perhaps. We also have to assume that 40 is really 4.0 in that question.
With g=0 yes the mean mag path length is:
pi*(Ro+Ri)
To determine if the mean mag path length is:
pi*(Ro+Ri)-g
where the two core face surfaces are perfectly parallel we'd have to dig a little deeper, but for very small 'g' i think it should be a good enough estimate.
The fact that the core permeability is infinite may change things too though because then the gap doesnt have any effect. That is if this is a little bit of a tricky question where it really is infinite and not just "large".
#### wayneh
Joined Sep 9, 2010
16,400
The fact that the core permeability is infinite may change things too though because then the gap doesnt have any effect.
I don't think you mean that. The gap is still a critical piece and it's size matters.
#### wayneh
Joined Sep 9, 2010
16,400
you mean
It might, by coincidence, produce the right result in this example. But the formula is incorrect. If anyone challenges you on that, tell them to imagine a toroid with Ro of 100 and Ri of 99. Do they really believe the mean core length is just 2π?
#### MrAl
Joined Jun 17, 2014
7,849
With reference to the gap size being insignificant if the permeability is infinite...
I don't think you mean that. The gap is still a critical piece and it's size matters.
Hi,
Well go through the calculation of inductance and see what you end up with.
I may have inverted the logic here, where instead the air gap now has total control over the average permeability.
From the point of view of reluctance it looks like the air gap takes control over the total reluctance completely.
So instead of zero control it has total control
I'll look at this too in more detail later.
|
{"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": 0.9393294453620911, "perplexity": 1745.9274203301534}, "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/1606141201836.36/warc/CC-MAIN-20201129153900-20201129183900-00110.warc.gz"}
|
https://investigadores.uandes.cl/es/publications/stochastic-model-calculation-for-the-carbon-monoxide-oxidation-on-3
|
# Stochastic model calculation for the carbon monoxide oxidation on iridium(111) surfaces
Jaime Cisternas*, Daniel Escaff, Orazio Descalzi, Stefan Wehner
*Autor correspondiente de este trabajo
Resultado de la investigación: Contribución a una revistaArtículorevisión exhaustiva
9 Citas (Scopus)
## Resumen
We study the effect of external noise on the catalytic oxidation of CO on an Iridium(111) single crystal under ultrahigh vacuum conditions. This reaction can be considered as a model of catalysis used in industry. In the absence of noise the reaction exhibits one or two stable stationary states, depending on control parameters such as temperature and partial pressures. When noise is added, for instance, by randomly varying the quality of the influx mixture, the system exhibits stochastic reaction rate and switching. In this work, we present two approaches: one for the monostable regime, and another for the bistable situation that relies on a white noise approximation. Both approaches rest on the assumption that spatial patterns of coverage on the Iridium plate can be neglected on a first approximation. Using mathematical models, it is possible to reconstruct stationary probability distribution functions that match experimental observations and provide support for the existence of a thermodynamic potential.
Idioma original Inglés 3461-3472 12 International Journal of Bifurcation and Chaos in Applied Sciences and Engineering 19 10 https://doi.org/10.1142/S0218127409024906 Publicada - oct. 2009
## Palabras clave
• Bistability
• Noise
• Stochastic differential equations
• Surface reactions
## Huella
Profundice en los temas de investigación de 'Stochastic model calculation for the carbon monoxide oxidation on iridium(111) surfaces'. En conjunto forman una huella única.
|
{"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": 0.8253195881843567, "perplexity": 3455.8339674354897}, "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-2022-40/segments/1664030335362.18/warc/CC-MAIN-20220929163117-20220929193117-00191.warc.gz"}
|
http://math.stackexchange.com/questions/4521/how-can-i-prove-this-trigonometric-equality
|
# How can I prove this trigonometric equality?
$$\arccos\left(\frac{1-x^2}{1+x^2}\right) = 2\arctan{x}$$ for $x \geq 0$.
I'm not even sure what kind of math to try? :(
-
Put $t=\arctan x$. Then $x=\tan t$. You have to prove that $2t=\arccos(1-x^2)/(1+x^2)$. This is more-or-less the same as $(1-x^2)/(1+x^2)=\cos2t$. If you put $x=\tan t$ into $(1-x^2)/(1+x^2)$ what do you get?
-
Setting $x=\tan a$ your equality
$$\arccos \dfrac{1-x^{2}}{1+x^{2}}=2\arctan x\qquad (1)$$
becomes
$$\cos 2a=\dfrac{1-\tan ^{2}a}{1+\tan ^{2}a}.\qquad (2)$$
To prove (2) which is listed in the wikipedia we can take the duplication formula
$$\cos 2a=\cos ^{2}a-\sin ^{2}a$$
Dividing by $\cos ^{2}a+\sin ^{2}a=1$, we establish
$$\cos 2a=\dfrac{\cos ^{2}a-\sin ^{2}a}{\cos ^{2}a+\sin ^{2}a}=\dfrac{1-\tan ^{2}a}{1+\tan ^{2}a}.$$
Edit: One must note that $\arctan x$ is an odd function, while $\arccos \frac{1-x^{2}}{1+x^{2}}$ is an even one. Only for $x\geq 0$ are both sides of $(1)$ equal. Identity $(2)$ is valid for both positive and negative values of $a$.
Blue: $y=\arccos((1-x^2)/(1+x^2))$ for $x\ge 0$; Red: $y=2\arctan x$
-
Thats what Robin answered? – anonymous Sep 13 '10 at 12:51
@Chandru1: similar, yes. I based my deduction in a general method I learned that all direct trigonometric function of the angle $2a$ may be expressed as rational function of $\tan a$. – Américo Tavares Sep 13 '10 at 12:59
@Chandru: The book is "Compêndio de Trigonometria" by J. Jorge Calado, Lisbon, Empresa Literária Fluminence, 1967. – Américo Tavares Sep 13 '10 at 13:03
Differentiate the difference $$\arccos\left(\frac{1-x^2}{1+x^2}\right) - 2\arctan{x},$$ simplify the resulting expression and find $0$ when $x>0$, concluding that the difference is constant. Now evaluate at $1$, to see that the difference is in fact constantly zero.
N.B.: This is of course quite unenlightenling, but you always know that if two things are equal, their difference is constant so you never lose much by trying to show that it is constant and zero. Specially if you have a computer algebra system at hand that can do the derivatives and simplifications for you!
-
|
{"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": 0.954366147518158, "perplexity": 457.6211057711494}, "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-2015-32/segments/1438042981460.12/warc/CC-MAIN-20150728002301-00078-ip-10-236-191-2.ec2.internal.warc.gz"}
|
http://math.stackexchange.com/users/8365/kuch-nahi?tab=activity&sort=revisions&page=3
|
# kuch nahi
less info
reputation
21349
bio website location age 26 member for 3 years, 10 months seen Oct 8 '14 at 3:32 profile views 672
Learning from scratch.
# 153 Revisions
Aug18 revised How to do this approximation? added 256 characters in body Aug17 revised Question on nonhomogeneous ODE edited title Aug17 revised Question on nonhomogeneous ODE deleted 11 characters in body Aug15 revised Prove that this equation has only one solution added 3 characters in body Aug15 revised Prove that this equation has only one solution added 458 characters in body Aug15 revised Prove that this equation has only one solution added 458 characters in body Aug9 revised Elementary Question about linear ODE added 20 characters in body Aug9 revised Elementary Question about linear ODE added 755 characters in body Aug9 revised Elementary Question about linear ODE added 35 characters in body Aug9 revised Elementary Question about linear ODE added 7 characters in body Aug6 revised What is the reason for these jiggles when truncating infinite series? deleted 13 characters in body Aug6 revised What is the reason for these jiggles when truncating infinite series? added 1 characters in body Aug6 revised Fibonacci recurrence relations added 235 characters in body Aug6 revised What could be an intuitive explanation for $\sum\limits_{k=1}^{\infty}\frac{1}{k2^k} = \log 2$? added 404 characters in body Aug6 revised What could be an intuitive explanation for $\sum\limits_{k=1}^{\infty}\frac{1}{k2^k} = \log 2$? added 62 characters in body Aug6 revised What could be an intuitive explanation for $\sum\limits_{k=1}^{\infty}\frac{1}{k2^k} = \log 2$? added 15 characters in body Aug6 revised What could be an intuitive explanation for $\sum\limits_{k=1}^{\infty}\frac{1}{k2^k} = \log 2$? deleted 5 characters in body Aug4 revised How to prove that exponential grows faster than polynomial? added 2 characters in body Jul24 revised Best way to set up a wiki for maintaining a structured math journal deleted 2902 characters in body Jul19 revised Every 3D rotation must have an axis? edited title
|
{"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": 0.38532906770706177, "perplexity": 2475.697842901066}, "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/1422121833101.33/warc/CC-MAIN-20150124175033-00250-ip-10-180-212-252.ec2.internal.warc.gz"}
|
https://listserv.uni-heidelberg.de/cgi-bin/wa?A2=0102&L=LATEX-L&D=0&P=2932194
|
## [email protected]
Options: Use Forum View Use Monospaced Font Show Text Part by Default Show All Mail Headers Message: [<< First] [< Prev] [Next >] [Last >>] Topic: [<< First] [< Prev] [Next >] [Last >>] Author: [<< First] [< Prev] [Next >] [Last >>]
Joseph Wright skrev:
> Lars Hellström wrote:
>> Finally, there is the issue that a processor has to put the argument in
>> a toks register. I understand this is for generality (only sane way to
>> pass along # tokens), but my experience with this type of API is that
>> one should make it easy to use commands that happen to already exist. In
>> this case, it would mean to also support a processor that would store
>> its result in a macro rather than a toks register, since I'm quite sure
>> this is what people tend to do unless they definitely need a toks register.
>
> Maybe I'm missing something here, but if we need the processed value
> returned in a named variable it should not matter whether it is a toks
> or a tl (or indeed anything else).
The point is that when specifying a processor, it's kind of a drag
having to introduce a helper function just for the purpose of glueing
xparse's syntax to that of an existing command really implementing the
operation; it would be much better if the syntaxes fitted from the
start. For operations that produce a sequence of tokens as result, I
believe the most common syntax would be the same as for \MakeHarmless,
i.e.,
\MakeHarmless<tl-to-set-to-result>{<input>}
(other examples more or less matching that syntax are \def and \edef).
Token registers, in my experience, is something you avoid using as
variables unless you have a specific need for them.
> All that needs to happen is
>
> \toks_set:NV \l_xparse_arg_toks <variable-used-in-processor>
>
> which is the same action if <variable-used-in-processor> is a tl or a
> toks.
Yes, but it is awkward to put that piece of code in the >{...}
modifier, since it must be executed *after* the actual processing step
has been carried out -- it pretty much requires a helper function to
rearrange things. Hence my suggestion that /xparse/ should supply that
piece of code, rather than rely on the user to do it.
Actually, a thing that worries me about the >{} syntax discussed so far
is that it presumes the programmer doing \DeclareDocumentCommand has
\ExplSyntaxOn, which I don't think is a safe bet; we're talking about
something which is somewhat like \newcommand. A better syntax might be
>{<variable>}{<processor>}
with the semantics that xparse will execute
<processor>{<argument>}
and expects to afterwards find the result in the <variable>,[*] which
it can then transfer to \l_xparse_arg_toks or perhaps pass directly to
the next processor. This adds the ability to use processors that leave
their result in a fixed place, but more importantly it avoid tying the
argspec syntax to implementation details of xparse.
[*] Okay, here that automagic "V" expansion type actually turns out to
be useful. :-o
Lars Hellström
|
{"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": 0.8076931238174438, "perplexity": 4888.768267610959}, "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/1642320304686.15/warc/CC-MAIN-20220124220008-20220125010008-00374.warc.gz"}
|
https://datascience.stackexchange.com/questions/29131/feature-names-in-logisticregression
|
# feature names in LogisticRegression()
I want to know feature names that a LogisticRegression() Model has used along with their corresponding weights in scikit-learn. I can access to weights using coef_, but i did not know how can pair them with their corresponding weights.
• I think the model just returns the coef_ in the same order as your input features, so just print them out one by one – Yang Song Mar 15 '18 at 21:16
• It's in the order of the columns by default... Also to get feature Importance from LR, take the absolute value of coefficients and apply a softmax on the same(be careful, some silver already do so in-built) – Aditya Mar 16 '18 at 0:18
We if you're using sklearn's LogisticRegression, then it's the same order as the column names appear in the training data. see below code.
#Train with Logistic regression
from sklearn.linear_model import LogisticRegression
from sklearn import metrics
model = LogisticRegression()
model.fit(X_train,Y_train)
#Print model parameters - the names and coefficients are in same order
print(model.coef_)
print(X_train.columns)
You may also verify using another library as below
import statsmodels.api as sm
logit_model=sm.Logit(Y_train,X_train)
result=logit_model.fit()
print(result.summary2())
from sklearn.feature_extraction.text import TfidfVectorizer
from sklearn.linear_model.logistic import LogisticRegression
from sklearn.metrics import accuracy_score
max_features = 100
tfidf = TfidfVectorizer(max_features=max_features)#stop_words='english',)# norm = None)#)
#Simple
texts_train = ['positive sample', 'again positive', 'negative sample', 'again negative']
target_train = [1,1,0,0]
texts_test = ['negative', 'positive']
target_test = [0,1]
texts_train1 = tfidf.fit_transform(texts_train)
texts_test1 = tfidf.transform(texts_test)
classifier = LogisticRegression()
classifier.fit(texts_train1, target_train)
predictions = classifier.predict(texts_test1)
print('accuracy (simple):', accuracy_score(target_test, predictions))
tfidf.get_feature_names()
['again', 'negative', 'positive', 'sample']
classifier.coef_
array([[ 0. , -0.56718183, 0.56718183, 0. ]]) that makes sense!
• @ keramat - does this means coefficients corresponds to the features in alphabetically sorted in ascending order? – KGhatak Dec 8 '19 at 12:46
• Never mind, found the answer (same as the comments to the original post) – KGhatak Dec 8 '19 at 13:27
|
{"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": 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": 0.28283923864364624, "perplexity": 5712.610266869726}, "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-2021-17/segments/1618038059348.9/warc/CC-MAIN-20210410210053-20210411000053-00495.warc.gz"}
|
http://web.colby.edu/thegeometricviewpoint/2014/11/23/the-long-line/
|
# The Geometric Viewpoint
geometric and topological excursions by and for undergraduates
## The Long Line
Topology can be best described as the study of certain “spaces” and the properties they have. Now it is important to figure out what spaces are essentially the “same” and which are different. We define two spaces to be the “same” if we can transform one into the other continuously, and the transformation we preformed can be undone continuously as well. Now you may be asking, “what exactly do you mean by a ‘space’?” A topological space is defined as a set $X$ with an associated set $\mathscr{T}$ consisting of subsets of $X$ which satisfies certain properties. The elements of $\mathscr{T}$ are declared to be the open sets of our topological space $(X,\mathscr{T})$.
Now a major aspect of topology is to define properties that different spaces could have and what these properties should “say” about a space. For example, one may want to determine when a space is connected together or when it can be broken up into different pieces. Or one may wish to determine when any two points in a space can be connected together by a path through the space. Now at first glance these two definitions seem to be describing the same property but in fact they aren’t. The first definition describes when a space is “connected” and the other when a space is “path-connected.” It turns out that “path-connected” is a stronger claim about a space than just “connected.” In other words, there are space which are connected but not path-connected, for example The Topologist’s Sine Curve . However every path-connected space is also connected. One may begin to wonder what other properties in topology share this type of connection. In other words, which properties imply other properties and which do not. Now to show that one property implies another, one must start from the most general assumptions and come up with some mathematical proof. However to show that some property does not imply another, one must simply come up with a counter example. It is the later strategy that this blog is concerned with. I will be discussing a particular topological space, “the long line,” that can be used as a counter example to certain properties of a space, namely different levels of “compactness.”
Before we begin discussing the long line it will be useful to have an overview of an order topology. Now on the real line $\mathbb{R},$ the order topology ends up coinciding with the usual definition of open set, namely the union of open intervals. The key property of the real line that allows us to have this definition of open intervals is that it is totally ordered. This simply means that given any two points $a,b \in \mathbb{R}$, either $a\leq b$ or $b\leq a$. It turns out that we can define an order topology on any set which is totally ordered by some relation $\leq.$ Given a totally ordered set $(X,\leq)$ we can define an order topology on $X$ by first letting $\mathscr{T}''$ be the set consisting of all sets of the form $\{y : y < a\}$ and $\{y : b for any $a,b \in X$. We then create another set $\mathscr{T}'$ of all the finite intersection of elements of $\mathscr{T}''$ and then let our topology $\mathscr{T}$ be all the sets which can be expressed as the arbitrary union and finite intersection of elements of $\mathscr{T}'$. The reader should think about this construction in terms of the real line and note that we end up producing all the open intervals and unions of open intervals of the real line. Refer to the image below to see how the construction comes together.
Example of the creation of an open interval with elements of T”.
We are almost ready to construct the long line, but first we must make one more detour, into the world of set theory. The principle object we will use in our construction of the long line is the ordinal. Ordinals are just a very special type of well ordered set. Now a well ordered set is very similar to a totally ordered set with the additional property that every non-empty subset has a minimum element. An amazing fact from set theory is that every set can be well ordered. It turns out that the ordinals can be thought of as the standard well ordered sets. In fact, every well ordered set can be put into a bijective correspondence which preserves order with a unique ordinal. Now you may be wondering what’s so special about these ordinals. An ordinal $X$ can be defined as a well ordered set with the property that each element $a \in X$ is exactly the set of all elements in $X$ which precede $a$. In other words, $X$ is an ordinal if for every element $a \in X$, $a = \{x \in X : x. The you may be wondering if such a thing even exists. Refer to the images for a glimpse of the finite and the first few infinite ordinals. You may be interested in a more thorough description of ordinals, which can be found here.
The first few finite ordinals.
The first few infinite ordinals.
Now it turns out that inclusion will always be the well order on an ordinal. It also turns out that there are a lot of ordinals. In fact the collection of all ordinals is not even a set! Naively we can think that there are just too many ordinals for them to be a set. Now as seen above there are ordinals with an infinite number of elements. In fact the first infinite ordinal can be used to make sense of the natural numbers. We often denote the first infinite ordinal as $w$. Amazingly there are different sized infinities, and $w$ can be thought of as the “smallest” infinity. Sets which can be put in a bijective correspondence with it are deemed “countable.” The next size of infinity is known as “uncountable” and we will let $\Omega$ stand for the first uncountable ordinal.
After the long build up we are finally ready to define the long line. The long line can be thought of as taking uncountably many copies of the interval $\lbrack 0,1)$ and “stacking” them end to end. For comparisons sake, we can think of the positive real line as countably many copies of the same interval “stacked” end to end. The long line must be very long indeed! While this definition may provide a good image, it leaves little to work with as far as properties go. Here is a more precise definition, the long line $L$ is the cartesian product $\Omega \times \lbrack 0,1)$ where the elements are ordered lexicographically. In other words, given two elements $(\alpha, a)$ and $(\beta,b)$ with $(\alpha, a)\leq (\beta,b)$, either $\alpha \leq \beta$ or in the case of equality, $a \leq b$. It is easy to see that this is a total order and so we can construct the order topology on $L.$ While this definition may seem strange, it is actually very easy to visualize. Take the set of all non-negative real numbers as an example. We can think of this set as the cartesian product $\mathbb{N} \times \lbrack 0,1)$ (keeping in mind that the natural number $\mathbb{N}$ can be fully described by the ordinal $w$). First note that we can think of elements $(n,d)$ of our set as telling us first the integer part of the number and then the decimal part. Now I ask the reader to consider how they would compare the size of two different positive real numbers. First you would compare the integer parts, and if they were equal you would then move on to the decimal parts. That’s comparing lexicographically! So the long line $L$ is just a much “longer” version of that example. The image below provides a description of our analogy to the long line, unfortunately it is very difficult to create a visual for an uncountable well ordered set.
The real line as a cartesian product.
Now you may wonder, “how much longer is the long line?” Perhaps the best way to compare the “length” of these lines is by looking at sequences. It is common knowledge that any strictly increasing sequence of real numbers does not converge. This is easily seen and accepted and it may be easy to conclude the same fact about the long line as well, however that would be a mistake.
Lemma 1: Every increasing sequence converges in the Long Line.
Proof: Suppose $(x_n)$ is an increasing sequence in the long line. Now consider the first element of each term of our sequence (remember elements of the long line are doubles, the first being the ordinal, and the second being the decimal part). Let $(\alpha_n)$ be the sequence of first elements. Therefore $(\alpha_n)$ is an increasing sequence of ordinal numbers. Now I will present it as fact that every increasing sequence of ordinal numbers has a limit point. Also $\Omega$ can never be the limit point of a sequence of countable ordinals. Therefore $(\alpha_n)$ must converge to a countable ordinal and therefore an ordinal that is represented in the long line. Now, if $(\alpha_n)$ never reaches a point where it remains constant, then we never have to consider the decimal part of the sequence since the limit point of the sequence of ordinals together with 0 will be the limit point of our sequence. So suppose that eventually $(\alpha_n)$ becomes a constant sequence. Let $\alpha'$ be the eventual constant term. Now we will consider the sequence of decimal parts of all terms after the sequence becomes constant in terms of the ordinals. Let $(d_m)$ be this sequence. Since $\lbrack 0,1)$ is bounded and $(d_m)$ must be increasing, it is easy to conclude that it converges, possibly to 1 in which case we take the point $(\alpha'+1,0)$ as our limit point for the original sequence. Therefore we can conclude that every increasing sequence converges in the long line. $\square$
Now amazingly with this one fact we glean even more information about the long line. For instance the long line is sequentially compact. First a quick definition, a topological space is sequentially compact if every sequence in the space has a convergent sub-sequence. Before I prove this I will prove a quick lemma about sequences in a totally ordered set.
Lemma 2: Every sequence in a totally ordered set has a monotone sub-sequence.
Proof: Suppose $(X,\leq)$ is a totally ordered set. Now let $(x_n)$ be a sequence in $X$. Let $x_p$ be a peak of the sequence if for all $n\geq p : x_n \leq x_p$. Now clearly there are two cases to consider, either $(x_n)$ has infinitely many such peaks or it has finitely many. First suppose that $(x_n)$ has infinitely many peaks, $\{x_{n_1}, x_{n_2},\ldots \}$. Therefore we can take $(x_{n_p})$ as our sub-sequence and clearly by definition this sequence must be decreasing. Now suppose our sequence has only finitely many peaks. Therefore there is a last peak $x_{n_{0-1}}$. Now consider the term $x_{n_0}$. Since this term is not a peak there must exist another term $x_{n_1}$ which is greater than $x_{n_0}$. We can then find a term $x_{n_2} \geq x_{n_1}$ since $x_{n_1}$ was not a peak. We can continue this process, creating a sub-sequence $(x_{n_m})$ which is increasing. $\square$
Now we are ready to prove that the Long Line $L$ is sequentially compact.
Proof: Suppose $(x_n)$ is a sequence in $L.$ By the second lemma we know we can find a monotone sub-sequence $(x_{n_m})$. Now first suppose that $(x_{n_m})$ is increasing. Then by the first lemma $(x_{n_m})$ converges. Now suppose that $(x_{n_m})$ is decreasing. Now since the long line is bounded below we know that $(x_{n_m})$ must converge. So $(x_n)$ has a convergent sub-sequence. $\square$
So the long line is sequentially compact. Of course the next question to ask is if the long line is compact. Interestingly it is not. Now the topological definition is a little different then the one given in most calculus classes. A topological space $X$ is compact if every open cover $\mathscr{U}$ of $X$ has a finite sub-cover. Now a cover is just a collection of open sets where the union of the collection is equal to the entire space.
Lemma 3: The Long Line $L$ is not compact.
Proof: Consider the collection of open sets $\mathscr{U'} = \{ (\alpha, \alpha+1) : \alpha \in \Omega \}$. We can then add to this collection sets of the form $((\alpha,\frac{2}{3}),(\alpha+1, \frac{1}{3}))$ giving us a cover $\mathscr{U}$. To see that this is a cover just note that the only points $\mathscr{U'}$ only misses the points with no decimal part, and note that the added collection of sets catch all the ordinals with no decimal part. Finally note that if any set of $\mathscr{U}$ is removed, we will no longer have a cover of $L$ and since $\mathscr{U}$ is clearly infinite we can conclude that $L$ is not compact. $\square$
This then leads us to one more interesting aspect of the long line; the long line is not metrizable. Now before I can explain what a metrizable space is, I will give a brief description of a metric space. A metric space is a set together with a “distance” function that determines how far away two points are. Open sets are then the union of open balls, which is just the set of all points strictly less than some radius from a given point. For instance, the usual distance function, $d$, on $\mathbb{R}$ is just $d(a,b) = |a-b|$. Open balls then correspond to sets of the form $\{x\in \mathbb{R} : |a-x| < \epsilon\}$. Now a metrizable space is a topological space where one can create a distance function on the set that then creates precisely the same open sets that were in the original topology. Now metric spaces, and therefore metrizable spaces, usually have “nicer” properties than general topological spaces, especially when it comes to equivalent features. The property that interests us here is than in a metric space, and so a metrizable space, the concept of sequentially compact and compact coincide. In other words, if a metric space is compact, then it is sequentially compact, and likewise in reverse. So immediately we can see that the long line cannot be metrizable since it is sequentially compact but not compact. So it would be impossible to create a “distance” function, which made sense, on the long line which lead to the construction of all the open sets we have.
Now you may be wondering what’s the point of creating the long line. You may ask yourself why anyone should care. Aside from just being able to work with a weird topological space, the creation and examination of the long line has multiple benefits. First off, it gives us a concrete counter example to properties that seem so similar. If all you ever work with are metrizable spaces, you won’t ever be able to really see how sequentially compact and compact are different. The long line is just one example of the importance of searching for counter examples. One may think that it is possible for spaces to have some properties and not have others, but until a concrete counter example is created, it’s all just conjecture.
For more information on the long line refer to Counter Examples in Topology, Steen and Seebach.
Editor’s note: The author of this post Josh Hews was a student in the Fall 2014 Topology course at Colby College taught by Scott Taylor. Submissions to the blog of essays by and for undergraduates on subjects pertaining to geometry and topology are welcome. For more information see the “Submit and Essay” tab above.
This entry was posted in Uncategorized. Bookmark the permalink.
|
{"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": 101, "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": 0.958020031452179, "perplexity": 139.19841171900413}, "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-2019-47/segments/1573496669795.59/warc/CC-MAIN-20191118131311-20191118155311-00148.warc.gz"}
|
https://figshare.com/articles/The_role_of_phytochromes_in_cadmium_stress_responses_in_tomato/5720587/1
|
## The role of phytochromes in cadmium stress responses in tomato
2017-12-01T03:07:55Z (GMT) by
<div><p>ABSTRACT It is well known that phytochromes mediate a wide range of photomorphogenic processes in plants. In addition, many studies have demonstrated the involvement of phytochromes as part of abiotic stress signaling responses. However, little is known about cadmium (Cd) stress regulation by phytochromes. Thus, in this study, we used the phyA (far red-insensitive; fri), phyB1 (temporary redinsensitive; tri) and phyB2 (phyB2) tomato (Solanum lycopersicum L.) mutants to investigate the roles of these three phytochromes on Cd stress responses. The plants were grown over a 21-d period in the presence of Cd. We evaluated plant growth, Cd and chlorophyll content and anatomical changes in the leaves. The results indicated that all genotypes were affected by Cd and showed reduced growth of the shoots and roots, as well as reduced chlorophyll content. The accumulation of Cd was similar for all genotypes, and a higher Cd content was found in roots. Anatomical analysis of the vascular bundles revealed that fri and tri seem to be more disrupted by Cd. Overall, these results indicate that phytochromes do not determine Cd stress tolerance in tomato plants.</p></div>
|
{"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": 0.8247207403182983, "perplexity": 6881.178826106575}, "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-2018-51/segments/1544376827992.73/warc/CC-MAIN-20181216191351-20181216213351-00094.warc.gz"}
|
http://physics.stackexchange.com/questions/4364/does-the-positive-mass-conjecture-indicate-a-necessity-of-interactions-in-our-un?answertab=votes
|
# Does the positive mass conjecture indicate a necessity of interactions in our universe?
The positive mass conjecture was proved by Schoen and Yau and later reproved by Witten. Total mass in a gravitating system must be positive except in the case of flat Minkowski space, where energy is zero. Since QG is intended to be a theory of interaction with force particles called gravitons, one may begin to wonder if the interactions are in fact the important defining features of the space in question. So does a theory with interactions also require that space be curved?
-
Dear Humble, because non-gravitational yet interacting field theories such as QCD or the Standard Model exist and they don't predict a curved space, the answer to your question is clearly No, interactions don't imply that the spacetime has to be curved.
However, the curved spacetime follows from many other assumptions - or combinations of assumptions - for example from the requirement that the gravitational force (respecting the equivalence principle) simultaneously exists with the relativistic Lorentz invariance.
The theorems you mentioned clearly assumed that the spacetime is allowed to become curved.
So far, I assumed that you agree that the existence of interactions is a property of a theory, not a property of a configuration. But what about the possibility that you meant the "existence of interactions" to be a property of a state, or a configuration?
Because the positive-energy theorem implies that the energy is strictly positive with the single exception of an empty Minkowski space, it follows that if you also agree that the Minkowski space "has no interactions in it", then every state that has interactions "in it" has nonzero energy and consequently has to lead to a curved spacetime.
-
Lubos, I have always assumed that a QG theory replaced any curvature (and hence any curvature in geodesics) with gravitons interactions between matter fields. Is this assumption a wrong one? If that is so, then the role of the graviton in such theory would be VERY different than in other QFT. In fact, then why do we need gravitons in the first place then? – lurscher Feb 1 '11 at 15:28
|
{"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": 0.9573874473571777, "perplexity": 375.28083105809105}, "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-2013-48/segments/1387345777160/warc/CC-MAIN-20131218054937-00041-ip-10-33-133-15.ec2.internal.warc.gz"}
|
https://nonlinearalgebra.wordpress.com/2016/06/28/wnt-signaling-pathway/
|
# Wnt Signaling Pathway
In a previous post we discussed the significance of chemical reaction networks, the equations that arise from such networks, and our goals in solving them. Since then, the group has been working on creating a Macaulay2 package that takes a chemical reaction network as input and through various commands gives output reflecting the steady-state equations, a basis for the stoichiometric subspace, etc. We have created building blocks within the package which correspond to the motifs described in this paper. The idea is that these motifs can be used to create new reaction networks without the need to input every single reaction.
As an additional example in the package we added the shuttle model of the Wnt signaling pathway described in this paper. These are the chemical reactions in the model:
Trying to input these reactions (which are not based on any of the motifs we have already created) in our package we ran into a problem when trying to understand how to deal with the empty set present in 4 of the reactions above.
From an algebraic point of view, the two reactions of the form
$x_{**} \xrightarrow{k} x_{**}+\emptyset$
can be viewed without the empty set. Its significance in the reaction network is that there is degradation of the protein $\beta$-catenin; however, deleting the $"+ \emptyset"$ part will not change anything in the equations or the properties of the variety.
For reactions of the form
$X \xrightarrow{k} \emptyset~~~(1)$ and $\emptyset \xrightarrow{k} Y~~(2)$
we have to be more careful. We think of each complex in the reaction network as a monomial represented by an exponent vector. In the case above we have 19 species, so each exponent vector will be of dimension $19\times 1$. For example, the complex $x_2+x_4$ will have ones in the second and fourth position and all other entries will be zero. But how do we deal with the empty set? We can think of it as the monomial 1, with exponent vectors of all zeros. This is significant for reactions of the form $(1)$, since the rate constant $k$ will appear in the steady-state equation for $\dot{X}$. Aside from this, the empty set does not participate in the stoichiometric or steady-state equations.
From a biology standpoint, the reaction of type $(1)$ represents the degradation of the protein $\beta$-catenin, and the reaction of type $(2)$ – the production of $\beta$-catenin.
From a technical point of view, we need to revise our package so that it accepts an empty set symbol and associates an exponent vector of zeros with it, however, it does not add it to the species list.
|
{"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": 0.9438071846961975, "perplexity": 474.01502429851945}, "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-2019-09/segments/1550247511174.69/warc/CC-MAIN-20190221213219-20190221235219-00233.warc.gz"}
|
http://mathhelpforum.com/algebra/29167-algebra.html
|
1. ## Algebra
I am doing proof by induction for my discrete math class by I'm horrible at algebra and I can't figure this last part out. Thanks in advance for the advice.
I need to make: (10^k) -1 + (9)(10^k)
look like this: 10^(k+1) -1
I also need help with this one:
I need to make: 1 - 1/(k+1) + 1/(k+1)(k+2) (1 is numerator, rest is Denom)
look like this: 1 - 1/(k+2)
2. Originally Posted by jzellt
...
I need to make: (10^k) -1 + (9)(10^k)
look like this: 10^(k+1) -1
...
$\displaystyle 10^k - 1 +9 \cdot 10^k = 10^k - 1 +(10 -1) \cdot 10^k = 10^k - 1 +10 \cdot 10^k - 10^k= -1 + 10 \cdot 10^k = 10^{k+1}-1$
3. Thank you! Any advice for the second problem?
4. Originally Posted by jzellt
...
I also need help with this one:
I need to make: 1 - 1/(k+1) + 1/(k+1)(k+2) (1 is numerator, rest is Denom)
look like this: 1 - 1/(k+2)
$\displaystyle 1-\frac1{k+1}+\frac1{(k+1)(k+2)}= 1-\frac{k+2}{(k+1)(k+2)} + \frac{1}{(k+1)(k+2)} = 1- \frac{k+2-1}{(k+1)(k+2)}$
Nowyou can cancel (k+1). You should add to the final result that $\displaystyle k \ne -1$
5. I got up until the final step you have. After I find the common denominator of (k+1)(k+2), I add up the number and get (k+2) + 1. How did you get (k+2) - 1?
6. Originally Posted by jzellt
I got up until the final step you have. After I find the common denominator of (k+1)(k+2), I add up the number and get (k+2) + 1. How did you get (k+2) - 1?
the minus sign in front of the $\displaystyle \frac {k + 2}{(k + 1)(k + 2)}$ is what yielded the -1
note: $\displaystyle - \frac {k + 2}{(k + 1)(k + 2)} + \frac 1{(k + 1)(k + 2)} = \frac {1 - (k + 2)}{(k + 1)(k + 2)} = - \frac {(k + 2) - 1}{(k + 1)(k + 2)}$
got it?
can you continue?
|
{"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": 0.8003365993499756, "perplexity": 1435.0933077863958}, "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-2018-17/segments/1524125948089.47/warc/CC-MAIN-20180426051046-20180426071046-00111.warc.gz"}
|
https://dspace.lboro.ac.uk/dspace-jspui/handle/2134/1228
|
Loughborough University
Leicestershire, UK
LE11 3TU
+44 (0)1509 263171
# Loughborough University Institutional Repository
Please use this identifier to cite or link to this item: https://dspace.lboro.ac.uk/2134/1228
Title: Time discretization of functional integrals Authors: Samson, J.H. Keywords: quantum physicsstatistical mechanics Issue Date: 2000 Abstract: Numerical evaluation of functional integrals usually involves a finite (L-slice) discretization of the imaginary-time axis. In the auxiliary-field method, the L-slice approximant to the density matrix can be evaluated as a function of inverse temperature at any finite L as $\rho_L(\beta)=[\rho_1(\beta/L)]^L$, if the density matrix $\rho_1(\beta)$ in the static approximation is known. We investigate the convergence of the partition function $Z_L(\beta)=Tr\rho_L(\beta)$, the internal energy and the density of states $g_L(E)$ (the inverse Laplace transform of $Z_L$), as $L\to\infty$. For the simple harmonic oscillator, $g_L(E)$ is a normalized truncated Fourier series for the exact density of states. When the auxiliary-field approach is applied to spin systems, approximants to the density of states and heat capacity can be negative. Approximants to the density matrix for a spin-1/2 dimer are found in closed form for all L by appending a self-interaction to the divergent Gaussian integral and analytically continuing to zero self-interaction. Because of this continuation, the coefficient of the singlet projector in the approximate density matrix can be negative. For a spin dimer, $Z_L$ is an even function of the coupling constant for L<3: ferromagnetic and antiferromagnetic coupling can be distinguished only for $L\ge 3$, where a Berry phase appears in the functional integral. At any non-zero temperature, the exact partition function is recovered as $L\to\infty$. Description: This is a pre-print. It is also available at: http://arxiv.org/abs/quant-ph/0003109. The definitive version: SAMSON, 2000. Time discretization of functional integrals. Journal of Physics A: Mathematical and General, 33, 3111-3120, is available at: http://www.iop.org/EJ/journal/JPhysA. URI: https://dspace.lboro.ac.uk/2134/1228 Appears in Collections: Pre-Prints (Physics)
Files associated with this item:
File Description SizeFormat
|
{"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": 0.9475408792495728, "perplexity": 986.4537588417173}, "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/1432207930443.64/warc/CC-MAIN-20150521113210-00136-ip-10-180-206-219.ec2.internal.warc.gz"}
|
http://www.mathmaa.com/apset-syllabus3-4.html
|
online user counter
MATHMAA
Only Search Your Site
# APSET Syllabus3&4
## Probability Introduction :
APSET Syllabus3&4 units continuation
UNIT – 3
Ordinary Differential Equations (ODEs):
Existence and uniqueness of solutions of initial value problems for first order ordinary differential equations, singular solutions of first order ODEs, system of first order ODEs.
General theory of homogenous and non-homogeneous linear ODEs, variation of parameters, Sturm-Liouville boundary value problem, Green’s function.
Partial Differential Equations (PDEs):
Lagrange and Charpit methods for solving first order PDEs, Cauchy problem for first order
PDEs.
Classification of second order PDEs, General solution of higher order PDEs with constant coefficients, Method of separation of variables for Laplace, Heat and Wave equations.
Numerical Analysis:
Numerical solutions of algebraic equations, Method of iteration and Newton-Raphson method, Rate of convergence, Solution of systems of linear algebraic equations using Gauss elimination and Gauss-Seidel methods, Finite differences, Lagrange, Hermite and spline interpolation, Numerical differentiation and integration, Numerical solutions of ODEs using Picard, Euler, modified Euler and Runge-Kutta methods.
Calculus of Variations:
Variation of a functional, Euler-Lagrange equation, Necessary and sufficient conditions for
extrema. Variational methods for boundary value problems in ordinary and partial differential
equations.
Linear Integral Equations:
Linear integral equation of the first and second kind of Fredholm and Volterra type, Solutions
with separable kernels. Characteristic numbers and eigenfunctions, resolvent kernel.
Classical Mechanics:
Generalized coordinates, Lagrange’s equations, Hamilton’s canonical equations, Hamilton’s
principle and principle of least action, Two-dimensional motion of rigid bodies, Euler’s
dynamical equations for the motion of a rigid body about an axis, theory of small oscillations.
APSET Syllabus3&4
UNIT – 4
Descriptive statistics, exploratory data analysis
Sample space, discrete probability, independent events, Bayes theorem. Random variables and distribution functions (univariate and multivariate); expectation and moments.
Independent random variables, marginal and conditional distributions. Characteristic functions. Probability inequalities (Tchebyshef, Markov, Jensen). Modes of convergence, weak and strong laws of large numbers, Central Limit theorems (i.i.d. case).
Markov chains with finite and countable state space, classification of states, limiting behavior of n-step transition probabilities, stationary distribution, Poisson and birth-and-death processes.
Standard discrete and continuous univariate distributions. sampling distributions, standard
errors and asymptotic distributions, distribution of order statistics and range.
Methods of estimation, properties of estimators, confidence intervals. Tests of hypotheses: most powerful and uniformly most powerful tests, likelihood ratio tests. Analysis of discrete data and chi-square test of goodness of fit. Large sample tests.
Simple nonparametric tests for one and two sample problems, rank correlation and test for
independence. Elementary Bayesian inference.
Gauss-Markov models, estimability of parameters, best linear unbiased estimators, confidence intervals, tests for linear hypotheses. Analysis of variance and covariance. Fixed, random and mixed effects models. Simple and multiple linear regression. Elementary regression diagnostics.
Logistic regression.
Multivariate normal distribution, Wishart distribution and their properties. Distribution of
quadratic forms. Inference for parameters, partial and multiple correlation coefficients and
related tests. Data reduction techniques: Principle component analysis, Discriminant analysis,
Cluster analysis, Canonical correlation.
Simple random sampling, stratified sampling and systematic sampling. Probability proportional to size sampling. Ratio and regression methods. Completely randomized designs, randomized block designs and Latin-square designs. Connectedness and orthogonality of block designs, BIBD. 2K factorial experiments: confounding and construction.
Hazard function and failure rates, censoring and life testing, series and parallel systems.
Linear programming problem, simplex methods, duality. Elementary queuing and inventory models. Steady-state solutions of Markovian queuing models: M/M/1, M/M/1 with limited waiting space, M/M/C, M/M/C with limited waiting space, M/G/1
This is the APSET Syllabus3&4 for mathematical science.
|
{"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": 0.8029930591583252, "perplexity": 3541.438362857635}, "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-2019-47/segments/1573496668539.45/warc/CC-MAIN-20191114205415-20191114233415-00253.warc.gz"}
|
https://www.physicsforums.com/threads/transfer-function-for-a-rlc-circuit.242190/
|
Transfer Function for a || RLC Circuit
1. Jun 26, 2008
TheAshlander
Hey all, I'm a new member, so nice to meet you all!
1. The problem statement, all variables and given/known data
I'm currently in the process for deriving the Transfer Function H(s) and H(jw) (w read as omega for angular frequency) for http://www.ebfreedom.com/fwajx/cDiag.jpg" [Broken]
I have taken several approaches but have not been able to land on anything completely. I will post my initial work, albeit is not much, but is the basis for my different techniques..
2. Relevant equations
Vo/Vi, s = jw
3. The attempt at a solution
The idea I see here is to take the Equivalent Impedance of the Inductor and Capacitor in parallel, along with the internal resistance of the inductor. Oh yeah, the output voltage is to be read across the capacitor (or the open circuit). Well, here's the math:
I'll call R the series addition of R3 and R4, and R5 will be the internal resistance of the inductor.
Equiv Imp. of parallel inductor & capacitor: ((Ls + R5)/(Cs))/(Ls+R5+1/cS)) can be simplified to ((Ls+R5)/(CLs^2 + R5Cs + 1))
into the formal equation: Vo/Vi => (1/Cs)/(R + ((Ls+R5)/(CLs^2 + R5Cs + 1))
If you would like to see my failed attempts, I will surely post them.
Last edited by a moderator: May 3, 2017
2. Jun 27, 2008
CEL
Call Z the impedance of the parallel inductor-capacitor. Using a voltage divider you get:
$$\frac{V_o}{V_i}=\frac{Z}{R+Z}$$
3. Jun 29, 2008
TheAshlander
If it's possible to please delete this post, please do so! I can't find the delete post button and I can't seem to edit my own post..
Similar Discussions: Transfer Function for a || RLC Circuit
|
{"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": 0.6012125015258789, "perplexity": 1777.6028405151749}, "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-2017-39/segments/1505818690228.57/warc/CC-MAIN-20170924224054-20170925004054-00331.warc.gz"}
|
https://www.iaa.csic.es/publications/observational-evidence-energetic-particle-precipitation-nox-epp-nox-interaction
|
# Observational evidence of energetic particle precipitation NO<SUB>x</SUB> (EPP-NO<SUB>x</SUB>) interaction with chlorine curbing Antarctic ozone loss
DOI:
10.5194/acp-21-2819-2021
Publication date:
24/02/2021
Main author:
Gordon, Emily M.
IAA authors:
Funke, Bernd
Authors:
Gordon, Emily M.;Seppälä, Annika;Funke, Bernd;Tamminen, Johanna;Walker, Kaley A.
Journal:
Atmospheric Chemistry & Physics
Refereed:
Yes
Publication type:
Article
Volume:
21
Pages:
2819
Abstract:
We investigate the impact of the so-called energetic particle precipitation (EPP) indirect effect on lower stratospheric ozone, ClO, and ClONO<SUB>2</SUB> in the Antarctic springtime. We use observations from the Microwave Limb Sounder (MLS) and Ozone Monitoring Instrument (OMI) on Aura, the Atmospheric Chemistry Experiment - Fourier Transform Spectrometer (ACE-FTS) on SCISAT, and the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on Envisat, covering the period from 2005 to 2017. Using the geomagnetic activity index Ap as a proxy for EPP, we find consistent ozone increases with elevated EPP during years with an easterly phase of the quasi-biennial oscillation (QBO) in both OMI and MLS observations. While these increases are the opposite of what has previously been reported at higher altitudes, the pattern in the MLS O<SUB>3</SUB> follows the typical descent patterns of EPP-NO<SUB>x</SUB>. The ozone enhancements are also present in the OMI total O<SUB>3</SUB> column observations. Analogous to the descent patterns found in O<SUB>3</SUB>, we also found consistent decreases in springtime MLS ClO following winters with elevated EPP. To verify if this is due to a previously proposed mechanism involving the conversion of ClO to the reservoir species ClONO<SUB>2</SUB> in reaction with NO<SUB>2</SUB>, we used ClONO<SUB>2</SUB> observations from ACE-FTS and MIPAS. As ClO and NO<SUB>2</SUB> are both catalysts in ozone destruction, the conversion to ClONO<SUB>2</SUB> would result in an ozone increase. We find a positive correlation between EPP and ClONO<SUB>2</SUB> in the upper stratosphere in the early spring and in the lower stratosphere in late spring, providing the first observational evidence supporting the previously proposed mechanism relating to EPP-NO<SUB>x</SUB> modulating Cl<SUB>x</SUB>-driven ozone loss. Our findings suggest that EPP has played an important role in modulating ozone depletion in the last 15 years. As chlorine loading in the polar stratosphere continues to decrease in the future, this buffering mechanism will become less effective, and catalytic ozone destruction by EPP-NO<SUB>x</SUB> will likely become a major contributor to Antarctic ozone loss.
Database:
|
{"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": 0.8749186992645264, "perplexity": 7175.117736595882}, "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-2022-49/segments/1669446710765.76/warc/CC-MAIN-20221130160457-20221130190457-00209.warc.gz"}
|
http://xps.apmonitor.com/wiki/index.php/Apps/GibbsFreeEnergy
|
Apps
Gibbs Free Energy
In thermodynamics, the Gibbs free energy is a thermodynamic potential that measures the "useful" or process-initiating work obtainable from an isothermal, isobaric thermodynamic system. Gibbs energy is also the chemical potential that is minimized when a system reaches equilibrium at constant pressure and temperature. As such, it is a convenient criterion of spontaneity for processes with constant pressure and temperature. Every system seeks to achieve a minimum of free energy. Out of this general natural tendency, a quantitative measure as to how near or far a potential reaction is from this minimum is when the calculated energetics of the process indicate that the change in Gibbs free energy is negative. In essence, this means that such a reaction will be favoured and will release energy. The energy released equals the maximum amount of work that can be performed as a result of the chemical reaction. In contrast, if conditions indicated a positive change in Gibbs free energy, then energy, in the form of work, would have to be added to the reacting system to make the reaction go.
The equation can also be seen from the perspective of both the system and its surroundings (the universe). For the purposes of calculation, we assume the reaction is the only reaction going on in the universe. Thus the entropy released or absorbed by the system is actually the entropy that the environment must absorb or release respectively. Thus the reaction will only be allowed if the total entropy change of the universe is equal to zero (an equilibrium process) or positive. The input of heat into an "endothermic" chemical reaction (e.g. the elimination of cyclohexanol to cyclohexene) can be seen as coupling an inherently unfavourable reaction (elimination) to a favourable one (burning of coal or the energy source of a heat source) such that the total entropy change of the universe is more than or equal to zero, making the Gibbs free energy of the coupled reaction negative.
This optimization problem determines the mole fractions of a mixture of common combustion species at equilibrium by minimizing the Gibbs Energy.
Name
Lower
Value
Upper
gibbs.t
---
1.0000E+03
---
gibbs.p
---
2.0000E+00
---
gibbs.x[1]
1.0000E-04
3.9421E-01
---
gibbs.x[2]
1.0000E-04
1.0316E+00
---
gibbs.x[3]
1.0000E-04
1.2432E+00
---
gibbs.x[4]
1.0000E-04
3.6261E-01
---
gibbs.x[5]
1.0000E-04
5.1800E+00
---
gibbs.z
1.0000E-01
9.9953E-01
---
gibbs.y[1]
---
4.8007E-02
---
gibbs.y[2]
---
1.2563E-01
---
gibbs.y[3]
---
1.5139E-01
---
gibbs.y[4]
---
4.4158E-02
---
gibbs.y[5]
---
6.3081E-01
---
References
Lwin, Y., Chemical Equilibrium by Gibbs Energy Minimization on Spreadsheets, Int. J. Engng Ed. Vol. 16, No. 4, pp. 335-339, 2000.
|
{"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": 0.9087912440299988, "perplexity": 330.320125329044}, "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-2019-30/segments/1563195529480.89/warc/CC-MAIN-20190723151547-20190723173547-00517.warc.gz"}
|
https://brilliant.org/problems/geometric-progressions-2/
|
# Geometric progressions
Algebra Level 3
Consider a geometric progression which:-
• Starts with $$10!$$.
• Has a common ratio of 10.
Which term of this geometric progression is $$9! \times{10}^{10}$$?
Notation: $$!$$ denotes the factorial notation. For example, $$8! = 1\times2\times3\times\cdots\times8$$.
×
|
{"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": 0.9997696280479431, "perplexity": 3140.903484297697}, "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-2017-04/segments/1484560280763.38/warc/CC-MAIN-20170116095120-00499-ip-10-171-10-70.ec2.internal.warc.gz"}
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.