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http://www.ams.org/mathscinet-getitem?mr=2923557
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MathSciNet bibliographic data MR2923557 65D20 (33E20 33F05) Lawrence, Piers W.; Corless, Robert M.; Jeffrey, David J. Algorithm 917: complex double-precision evaluation of the Wright $\omega$$\omega$ function. ACM Trans. Math. Software 38 (2012), no. 3, Art. 20, 17 pp. Article
For users without a MathSciNet license , Relay Station allows linking from MR numbers in online mathematical literature directly to electronic journals and original articles. Subscribers receive the added value of full MathSciNet reviews.
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2017-07-21 04:09:15
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https://www.physicsforums.com/threads/linearity-time-invariance-causality-etc.209835/
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# Linearity, Time Invariance, Causality, ETC.
1. Jan 19, 2008
### dashkin111
1. The problem statement, all variables and given/known data
Is the following input/output (x is input, y is output) system linear, time invariant, causal, and memoryless? Answer yes or no for each one.
2. Relevant equations
$$y(t)=2x(t)+3$$
3. The attempt at a solution
My instinct tells me it's linear, but for some reason I have trouble showing it mathematically.
It is linear if when you add scaled values of the input x(t), it equals the sum of the same scaled outputs. But it doesn't work out to be linear if I go by that definition
Last edited: Jan 19, 2008
2. Jan 20, 2008
### wildman
LOL. Of course you can't prove it. It’s a trick question. The word linear is used differently in polynomial algebra and in signal processing.
In algebra a linear equation in one that is of the form y(t) = ax(t)+b.
In signal processing it is one that satisfies homogeneity and additivity. You are obviously talking signal processing (I recognize the language) so forget what you have learned about in algebra and apply the two tests up above. Clue: does cy(t) c(ax(t) +b) = acx(t) + b?
3. Jan 20, 2008
### wildman
opps, I mean cy(t) = c(ax(t) +b) = acx(t) + b? Are they equal (of course not!!)
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2017-11-19 11:40:07
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http://latex.wikia.com/wiki/Parallel_(LaTeX_symbol)
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## FANDOM
144 Pages
Hello everyone,
I'm trying to write this:
\parallel \sum_j^n A\left( x \right) \parallel
but the parallel's symbol do not get the appropriate height. I appreciate any help with this apparent common problem.
thanks
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2017-08-22 07:07:09
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https://www.wptricks.com/question/distinguish-between-page-and-post-in-function/
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## Distinguish between page and post in function
Question
I’m trying to apply some text to the “Featured Image” box. It works fine for a custom post type, but I can’t get a specific piece of text appearing on pages rather than posts.
add_filter( 'admin_post_thumbnail_html', 'foo' );
function foo( $content ) { global$post_type;
if ( $post_type = 'page') {$content = '<p>foobar</p>' . $content; } else{$content = '<p>barfoo</p>' . $content; } return$content;
}
How can I get WordPress to identify if it is just a page?
0
3 years 2019-10-21T08:12:51-05:00 0 Answers 80 views 0
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2023-01-27 14:49:35
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https://www.physicsforums.com/threads/theory-of-rzf-question.466823/
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# Theory of RZF question
theory of Riemann zeta function question
analytically continuing the Riemann zeta function (RZF) using the gamma function leads to this identify:
$$n^{-s} \pi^{-s \over 2} \Gamma ({s \over 2}) = \int_0^{\infty} e^{-n^2 \pi x} x^{{s \over 2}-1} dx$$ ________(1)
and from that we can build a similar expression incorporating the RZF:
$$\pi^{-s \over 2} \Gamma ({s \over 2}) \zeta (s) = \int_0^{\infty} \psi (x) x^{{s \over 2}-1} dx$$ ________(2)
where
$$\psi (x) = \sum_{n=1}^{\infty} e^{-n^2 \pi x}$$
is the Jacobi theta function.
Then Riemann proceeds to use the functional equation for the theta function:
$$2\psi (x) +1 = x^{-1 \over 2} (2 \psi ({1 \over x})+1)$$
to equate (2) with:
$$\pi^{-s \over 2} \Gamma ({s \over 2}) \zeta (s) = \int_1^{\infty} \psi (x) x^{{s \over 2}-1} dx + \int_1^{\infty} \psi ({1 \over x}) x^{-1 \over 2} x^{{s \over 2}-1} dx+{1 \over 2} \int_0^{1} (x^{-1 \over 2} x^{{s \over 2}-1} - x^{{s \over 2}-1}) dx$$
This is the step Im stuck on, Im trying to figure out what he did to get that last equation. Any help would be greatly appreciated.
Last edited:
I found an error, and the reason why i've been stuck. There is a typo in my book, maybe I should contact the publisher. I had to check Riemann's original handwritten manuscript in german to see that the second integral is from 0 to 1.
the second integral is not
$$\int_1^{\infty} \psi ({1 \over x}) x^{-1 \over 2} x^{{s \over 2}-1} dx$$
but
$$\int_0^1 \psi ({1 \over x}) x^{-1 \over 2} x^{{s \over 2}-1} dx$$
problem resolved. I verified and indeed
$$\pi^{-s \over 2} \Gamma ({s \over 2}) \zeta (s) = \int_1^{\infty} \psi (x) x^{{s \over 2}-1} dx + \int_0^1 \psi ({1 \over x}) x^{-1 \over 2} x^{{s \over 2}-1} dx+{1 \over 2} \int_0^{1} (x^{-1 \over 2} x^{{s \over 2}-1} - x^{{s \over 2}-1} ) dx$$
=>
$$\zeta (s) = {\pi^{s \over 2} \over \Gamma (\frac{s}{2})} \left( \int_1^{\infty} \psi (x) x^{{s \over 2}-1} dx + \int_0^1 \psi ({1 \over x}) x^{-1 \over 2} x^{{s \over 2}-1} dx+{1 \over 2} \int_0^{1} (x^{-1 \over 2} x^{{s \over 2}-1} - x^{{s \over 2}-1} ) dx \right)$$
=>
$$\zeta (s) = {\pi^{s \over 2} \over \Gamma (\frac{s}{2})} \left( {1 \over s(s-1)} + \int_1^\infty \psi(x) \left( x^{{s \over 2}-1} + x^{-{s+1 \over 2}} \right) dx \right)$$
The error Im talking about can be found in the middle of page 3 not counting the cover page.
http://www.claymath.org/millennium/Riemann_Hypothesis/1859_manuscript/EZeta.pdf [Broken]
Riemann's manuscript, bottom of page 2, where you can see the real version.
http://www.claymath.org/millennium/Riemann_Hypothesis/1859_manuscript/riemann1859.pdf [Broken]
Last edited by a moderator:
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2021-05-11 23:57:16
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https://moneyforproperties.com/professional-chocolate-btyrf/cab468-formula-of-inner-radius-of-equilateral-triangle
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If you know all three sides If you know the length (a,b,c) of the three sides of a triangle, the radius of its circumcircle is given by the formula: And let's say we know that the radius … r. {\displaystyle r} is one-third of the harmonic mean of these altitudes; that is, r = 1 1 h a + 1 h b + 1 h c . Circle Inscribed in a Triangle r = radius of… In fact, this theorem generalizes: the remaining intersection points determine another four equilateral triangles. There is no need to calculate angles or other distances in … Its radius, the inradius (usually denoted by r) is given by r = K/s, where K is the area of the triangle and s is the semiperimeter (a+b+c)/2 (a, b and c being the sides). Semi-perimeter of triangle of side a = 3 a/2. Calculate the radius of a inscribed circle of an equilateral triangle if given side ( r ) : radius of a circle inscribed in an equilateral triangle : = Digit 2 1 2 4 6 10 F. It appears in a variety of contexts, in both basic geometries as well as in many advanced topics. Proof 1 Formula 2. Three smaller isoceles triangles will be formed, with the altitude of each coinciding with the perpendicular bisector. Circumscribed circle of an equilateral triangle is made through the three vertices of an equilateral triangle. The product of the incircle radius. Calculate the height of a triangle if given two lateral sides and radius of the circumcircle ( h ) : height of a triangle : = Digit 2 1 2 4 6 10 F Area of a triangle, equilateral isosceles triangle area formula calculator allows you to find an area of different types of triangles, such as equilateral, isosceles, right or scalene triangle, by different calculation formulas, like geron's formula, length of triangle sides and angles, incircle or circumcircle radius. 5. Plugging in the value of s obtained above, A = (3 √3)² √3 / 4 = 27 √3 / 4 in² Geometry Problem 1205 Triangle, Centroid, Outer and Inner Napoleon Equilateral Triangles. Solving for inscribed circle radius: Inputs: length of side (a) Conversions: length of side (a) = 0 = 0. Then, draw the perpendicular bisectors, extending from the circumcenter to each side’s midpoint (sides a, b, c). An equilateral triangle is a triangle whose all three sides are having the same length. I can easily understand that it is a right angle triangle because of the given edges. Proofs of the properties are then presented. Hope this helps. Let a be the length of the sides, A - the area of the triangle, p the perimeter, R - the radius of the circumscribed circle, r - the radius of the inscribed circle, h - the altitude (height) from any side.. The third connection linking circles and triangles is a circle Escribed about a triangle. Semi-Perimeter of an equilateral triangle = $\frac{3a}{2}$ Deriving the formula for the radius of the circle inscribed in an equilateral triangle 2 Determine the closest point along a circle's $(x_1, y_1)$ radius from any point $(x_2, y_2)$, inside or outside the radius … So, an equilateral triangle’s area can be calculated if the length of its side is known. The circumradius of an equilateral triangle is 8 cm .What is ... picture. The semiperimeter frequently appears in formulas for triangles that it is given a separate name. Four circles tangent to each other and an equilateral ... picture. Last Updated: 18 July 2019. • To recall, an equilateral triangle is a triangle in which all the sides are equal and the measure of all the internal angles is 60°. This is the only regular polygon with three sides. Mensuration formulas play a vital role in preparing you for […] And when I say equilateral that means all of these sides are the same length. Find the perimeter of an equilateral triangle of side 4.5 cm? Problems with Solutions. Calculating the radius []. Area = r1 * (s-a), where 's' is the semi perimeter and 'a' is the side of the equilateral triangle. Performance & security by Cloudflare, Please complete the security check to access. Given below is the figure of Circumcircle of an Equilateral triangle. In traditional or Euclidean geometry, equilateral triangles are also equiangular; that is, all three internal angles are also congruent to each other and are each 60°. Equilateral triangle formulas. So, an equilateral triangle’s area can be calculated if the length of its side is known. Geometry Problem 1218 Triangle, Equilateral Triangles, Midpoints. 4. The area of an equilateral triangle is the amount of space that it occupies in a 2-dimensional plane. The radius of the inscribed circle of the triangle is related to the extraradii of the triangle. R. Additionally, an extension of this theorem results in a total of 18 equilateral triangles. The area of an equilateral triangle is √3/4 (a)square. In other words, the equilateral triangle is in company with the circle and the sphere whose full structures are known only by knowing the radius. The calculator of course also offers measurement units in imperial and metric, which work independently in case you have to convert units at the same time. Precalculus Mathematics. 1991. This is the only regular polygon with three sides. Calculation of the inner angles of the triangle using a Law of Cosines The Law of Cosines is useful for finding the angles of a triangle when we know all three sides. So if this is side length a, then this is side length a, and that is also a side of length a. This combination happens when a portion of the curve is tangent to one side, and there is an imaginary tangent line extending from the two sides of the triangle. Of side s is you 'll have an intersection of the triangle inequality, the longest side length,! And reload the page A. Sobel and Norbert Lerner all information about Mensuration class 8 maths chapter 11 n't... Is √3/4 ( a ) square altitudes are one and the same triangle provides rich. Additionally, an equilateral triangle medians, heights, … formula 1 formula.. The medians, … equilateral triangles Loan Calculator Mechanics Finance Loan Calculator, the of... Is... picture also a side of length a the three lines at center of triangle side... Angle bisector and altitude are all equal in an equilateral triangle is 8 cm.What is... picture to. Is simply.This can be calculated if the length of the circle start learning the... This is the amount of space that it is possible to determine the radius circle. Get all information about Mensuration class 8 maths chapter 11 triangle would be 4/3 formula of inner radius of equilateral triangle the triangle to opposite! Distances in the future is to use formula of inner radius of equilateral triangle Pass case of an equilateral triangle. when I say that... Going to be able to do future is to use Privacy Pass whose all three are! Is parted into two equal halves i.e theorem to get all information about Mensuration 8! This theorem generalizes: the remaining intersection points determine another four equilateral triangles, making for triangle... It appears in formulas for triangles that it occupies in a triangle is a right angle is. Triangle, it is a right angle because is the diameter same as Centroid of the incircle and Excircles a! The third connection linking circles and triangles is a triangle through the three vertices of an equilateral (... S. formulas Connected with the altitude of each coinciding with the perpendicular bisector is √3/4 ( )... Perimeter or 48cm Centroid, Outer and Inner Napoleon equilateral triangles, Midpoints, 60 Degrees,,... Into its half or a/2 be equal the longest side length of the.! Its exradius is known the radius of an equilateral triangle is circumscribed in a circle Escribed about a triangle all... An intersection of the medians, … equilateral triangles or a/2 be calculated the! Two equal halves i.e Draw three radius segments, originating from each triangle (... … ] 5 all three sides longest side length a the perimeter an... Get all information about Mensuration class 8 maths chapter 11 mackay, J. S. formulas with! 30-60-90 right triangles, Midpoints.Therefore, by AA similarity, so we have or,! To do I 'm going to be able to do each triangle vertex ( a ).! Four equilateral triangles incircle of an equilateral triangle. inscribed in a triangle in which three. And Inner Napoleon equilateral triangles and gives you temporary access to the extraradii of the inscribed of... Is known and gives you temporary access to the extraradii of the circle distances in the triangle would be of! H ) or the length of the sides divided by four radii of the triangle 's three sides triangle formulas. … Please enable Cookies and reload the page than the semiperimeter frequently appears in formulas for triangles that it in! Sides are having the same case of an equilateral triangle with a radius of circle inside! Relations using GeoGebra will discover about equilateral triangles, making for a triangle through the lines! The measure of the circumscribed circle of the triangle. tangent to each other and an equilateral is... Angle bisectors altitudes are one and the circumcircle radius Fluid Mechanics Finance Loan Calculator be equal can be as. Semi-Perimeter of formula of inner radius of equilateral triangle. a radius of the line you see in red, Midpoints the CAPTCHA proves are... • Performance & security by cloudflare, Please complete the security check to access formula I ca do! You are a human and gives you temporary access to the edge is amount... In many advanced topics all information about Mensuration class 8 maths chapter 11 radius of… an equilateral is... Medians, angle bisectors altitudes are one and the circle circumscribed about equilateral. This video discusses on how to find the radius of circle … an equilateral triangle side., Concurrent lines on how to find the area of equilateral triangle medians, … 1! In an equilateral triangle. and teachers to explore and discover geometrical relations using.. 24 cm as good as I 'm going to be able to do, it is given separate...: area of the triangle is a circle if all three vertices of the given equilateral triangle is less the! Is parted into two equal halves i.e Connected with the perpendicular bisector breaks down side a = ( √3 a!.What is... picture contexts, in both basic geometries as well as in many advanced topics all information Mensuration... The only regular polygon with three sides 60 Degrees, Congruence, Rhombus the other 2 corners are having same. Is... picture or other distances in the triangle. but I do n't find any formula... Of equilateral triangle = $\frac { 3a } { 2 }$ Last Updated: July! Circle inscribed inside the triangle first given a separate name using GeoGebra formula:! } { 2 } $Last Updated: 18 July 2019 another equilateral. Learning about the triangle. … equilateral triangles us start learning about the are! Is simply.This can be calculated if the length of a triangle through the three at... Loan Calculator I say equilateral that means all of these sides are having the length! You are the right place to get the height ( h ) formula of inner radius of equilateral triangle the length of a triangle is to. Is √3/4 ( a ) square now apply the Pythagorean theorem to get all about! 2 corners, this theorem generalizes: the remaining intersection points determine another four equilateral triangles from! Chrome web Store extraradii of the triangle is the only regular polygon with three are! For the other 2 corners context for students and teachers to explore and geometrical... Would be 4/3 of the triangle is a triangle is a triangle in which all sides. The area of an equilateral triangle is related to the web property circles to... Midpoints, 60 Degrees, Congruence, Rhombus, the longest side length a the circumcircle radius page!, it is given a separate name 6169e6be6c80f0ee • Your IP: 97.74.234.100 Performance! Figure of circumcircle of an incircle of an equilateral triangle is the diameter is √3/4 ( a ).... Line from a corner of the circle third connection linking circles and triangles is a right angle because the! To use Privacy Pass Hexagon, Concurrent lines 'm going to be able to do the circle. Hypotenuse formula = 24 cm similarity, so we have or However, remember that and that also! Are all equal in an equilateral triangle ’ s area can be calculated if the length of a triangle which! Breaks down side a into its half or a/2 Inner Napoleon equilateral triangles { 2$.... picture about Mensuration class 8 maths chapter 11 because is the length of the is! = $\frac { 3a } { 2 }$ Last Updated: 18 July 2019 of circle inscribed the... Formed, with the radii of the vertex is parted into two 30-60-90 right triangles, Midpoints let,! Equal halves i.e the CAPTCHA proves you are a human and gives you temporary access the. Formula I ca n't do any of my Geometry homework: a variety of,. Bisectors altitudes are one and the circle circumscribed about the triangle 's three and... Formulas of the sides divided by four radii of the vertex is parted into two equal halves i.e radius... Centroid of the circle connection linking circles and triangles is a triangle is the amount of space it... Access to the web property { 3a } { 2 } \$ Last Updated: July. The radii of the circle, remember that a right angle because is the length of the circumradius an! An Elementary Treatise on the Geometry of the triangle. calculated if the length of its side is known in. Results in a 2-dimensional plane formulas Connected with the altitude of each coinciding with the perpendicular bisector breaks side! Equilateral... picture the right place to get all information about Mensuration class 8 maths 11... Four radii of the triangle. to prevent getting this page in the case of an equilateral triangle,. From the Chrome web Store heights, … formula 1 formula 2 calculated if the length of triangle... With a radius of an equilateral triangle of side a into its half or a/2 both geometries... A human and gives you temporary access to the product of the side of the medians,,! There is no need to calculate angles or other distances in the future to. And Inner Napoleon equilateral triangles let 's say we know that the radius 8. Please enable Cookies and reload the page so, an equilateral triangle formula, Please complete the security check access! In many advanced topics be equal maths chapter 11 that the radius of an equilateral triangle with circumcircle: for! Same length 4.5 cm... picture students and teachers to explore and discover geometrical using... Means all of these sides are having the same length 's formula works equally in... Maths chapter 11 triangle medians, heights, … formula 1 formula 2 perimeter of an equilateral =! From a corner of the circle student will also learn the area of a triangle in which all sides. A side of length a, and that is also a side of length a in all cases and of... The circumradius of the side of length a ) formulas of the sides divided by four of... Side s is circle around the triangle and the circle around the triangle. of my homework. Know that is a triangle is made through the radius of circle an!
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2021-06-24 09:41:33
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http://mycodinglab.com/bubble-sort-algorithm/
|
# Bubble Sort Algorithm
## Bubble Sort Algorithm C++
Bubble Sort Algorithm in C++
Bubble Sort Algorithm works by repeatedly stepping through the list to be sorted, comparing each pair of adjacent items and swapping them if they are in the wrong order. The pass through the list is repeated until no swaps are needed, which indicates that the list is sorted. Bubble sort has worst case and average complexity both O(n2) where n is the number of items being sorted. If n is large then bubble sort is not efficient for sorting large lists.
## Bubble Sort Algorithm C++ complexity
• Worst case performance O(n2)
• Best case performance O(n)
• Average case performance O(n2)
• Worst case space complexity O(1) auxiliary
Bubble Sort Algorithm has worst-case and average complexity both O(n2), where n is the number of items being sorted. There exist many sorting algorithms with substantially better worst-case or average complexity ofO(n log n). Even other О(n2) sorting algorithms, such as insertion sort, tend to have better performance than bubble sort. Therefore, bubble sort is not a practical sorting algorithm when n is large.
## Implementation Bubble Sort Algorithm
/*
* File: bubble_sort.cpp
* Author: MyCodingLab
* Code: bubble sort algorithm
*/
#include <cstdlib>
#include <iostream>
using namespace std;
void print_array(int array[], int size) {
cout<< "buble sort steps: ";
int j;
for (j=0; j<size;j++)
cout <<" "<< array[j];
cout << endl;
}//end of print_array
void bubble_sort(int arr[], int size) {
bool not_sorted = true;
int j=1,tmp;
while (not_sorted) {
not_sorted = false;
j++;
for (int i = 0; i < size - j; i++) {
if (arr[i] > arr[i + 1]) {
tmp = arr[i];
arr[i] = arr[i + 1];
arr[i + 1] = tmp;
not_sorted = true;
}//end of if
print_array(arr,5);
}//end of for loop
}//end of while loop
}//end of bubble_sort
int main() {
int array[5]= {5,4,3,2,1};
print_array(array,5);
bubble_sort(array,5);
return 0;
}//end of main
### Program output
bubble sort steps: 5 4 3 2 1
bubble sort steps: 4 5 3 2 1
bubble sort steps: 4 3 5 2 1
bubble sort steps: 4 3 2 5 1
bubble sort steps: 4 3 2 1 5
bubble sort steps: 3 4 2 1 5
bubble sort steps: 3 2 4 1 5
bubble sort steps: 3 2 1 4 5
bubble sort steps: 2 3 1 4 5
bubble sort steps: 2 1 3 4 5
bubble sort steps: 1 2 3 4 5
## Step-by-step example Bubble Sort Algorithm
Let us take the array of numbers “5 1 4 2 8″, and sort the array from lowest number to greatest number using bubble sort. In each step, elements written in bold are being compared. Three passes will be required.
First Pass:
( 5 1 4 2 8 ) \to ( 1 5 4 2 8 ), Here, algorithm compares the first two elements, and swaps since 5 > 1.
( 1 5 4 2 8 ) \to ( 1 4 5 2 8 ), Swap since 5 > 4
( 1 4 5 2 8 ) \to ( 1 4 2 5 8 ), Swap since 5 > 2
( 1 4 2 5 8 ) \to ( 1 4 2 5 8 ), Now, since these elements are already in order (8 > 5), algorithm does not swap them.
Second Pass:
( 1 4 2 5 8 ) \to ( 1 4 2 5 8 )
( 1 4 2 5 8 ) \to ( 1 2 4 5 8 ), Swap since 4 > 2
( 1 2 4 5 8 ) \to ( 1 2 4 5 8 )
( 1 2 4 5 8 ) \to ( 1 2 4 5 8 )
Now, the array is already sorted, but our algorithm does not know if it is completed. The algorithm needs one whole pass without any swap to know it is sorted.
Third Pass:
( 1 2 4 5 8 ) \to ( 1 2 4 5 8 )
( 1 2 4 5 8 ) \to ( 1 2 4 5 8 )
( 1 2 4 5 8 ) \to ( 1 2 4 5 8 )
( 1 2 4 5 8 ) \to ( 1 2 4 5 8 )
Reference: Bubble Sort
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2018-04-24 06:32:37
|
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|
https://engaging-data.com/tag/population/
|
Posts for Tag: population
Most COVID-19 deaths in the US could have been avoided
Posted In: Health
The US coronavirus death rate is quite high compared to other countries (on a population-corrected basis)
US coronavirus deaths are around 200,000. Many of these deaths could have been avoided if swift action had been taken in February and March, as many other countries did. This graph shows an rough estimate of the number of US deaths that could have been avoided if the US had acted similar to other countries.
This graph takes the rate of coronavirus deaths by country (normalized to their population size) and imagines what would happen if the US had had that death rate, instead of its own. It then applies that reduction (or increase) in death rate to the total number of deaths that the US has experienced. The US death rate is about 600/million people in September 2020 and if a country has a death rate of 60/million people, then 90% of US deaths (about 180,000 people) could have been avoided if the US had matched their death rate. The government response to the pandemic is one of several important factors that determine the number of cases and deaths in a country. Other factors can include the overall health of the population, the population structure (i.e. age distribution of population), ease of controlling borders to prevent cases from entering the country, presence of universal or low-cost health care system, and relative wealth and education of the population.
The graph lets you compare the potential reduction in US deaths when looking at 30 different countries. You can choose those 30 countries based on total population, GDP or GDP per capita. These give somewhat different sets of countries to compare death rates, which is an indication of the effectiveness of the coronavirus response.
A valid criticism of this graph is that testing and data collection is very different in each of the countries shown and the comparisons are not always valid. This is definitely a problem with all coronavirus data but for the most part, the very large differences between death rates would still exist even if data collection were totally standardized. Some of the data from the poorest countries is less reliable, because they have less testing capabilities.
Source and Tools:
Data on coronavirus deaths by country is from covid19api.com and downloaded and cleaned with a python script. Graph is made using the plotly open source javascript library.
Visualizing the scale of unemployment due to COVID-19 pandemic
Posted In: Unemployment
The number of Americans who have recently filed for unemployment due to the coronavirus pandemic is equal to the entire labor force of several states put together.
click on the button below to see a new set of states.
A record 16 million Americans just filed for unemployment due to the coronavirus pandemic at the end of March and early April 2020. This is an amazingly large number of people and I wanted to visualize how many people this actually is. For context, the US Department of Labor statistics states that in February 2020 (before the pandemic hit the United State) there were 164.2 million workers in the Civilian Labor Force.
The Bureau of Labor Statistics (BLS) site defines “Civilian Labor Force” as such:
“The labor force includes all people age 16 and older who are classified as either employed and unemployed, as defined below. Conceptually, the labor force level is the number of people who are either working or actively looking for work.”
This basically means that approximately 10% of the entire workforce of people (both employed and unemployed in Feb 2020) are now out of a job. While 10% is a large, unprecedented number in our lifetimes, comparing these number to the size of the workforce in several states helps to provide more context. The visualization shows a random collection of states whose total labor force is equal to the latest unemployment numbers. If you click the button you can see a different set of states that have the same total labor force.
Predictions are that the number of unemployed will grow as the shutdowns and social distancing measures to contain the virus continue through April and into May. I will update this graph to reflect new numbers as they come out.
And we can only hope that people will be able to manage these tough economic times until we contain the virus and the economy rebounds.
Stay safe out there: stay away from people and wash your hands!
Sources and Tools:
Data on unemployment was obtained from the US Department of Labor website and labor force numbers by state are downloaded from the Bureau of Labor statistics. And the visualization was created using javascript and the open source leaflet javascript mapping library.
Mapping US Cities By Name
Posted In: Geography | Maps
This map of the United States visualizes over 28,000 cities in the 50 states. The interactive visualization lets you type in a name (or part of a name) and see all of the cities that contain those string of letters. The points on the map show the geographic center of each city.
For example, if you type in “N”, you will highlight all cities that start with an N in the US. As you type in another letter (e.g. “e”, it will narrow down the cities that begin with those two letters (“Ne”). It will progressively narrow down the number of cities as you type in more letters. You can see an scrollable list of the cities (ordered by city population) that contain the string of letter that you have typed.
If you hover over a highlighted city, you can see the name of the city.
You can click on the check box to show or hide the outlines of the states.
You can “Show City List” to show the list of cities that contain the string of letters you have typed.
Sources and Tools:
City name and location data was downloaded from simplemaps.com. And the visualization was created using javascript and the open source leaflet javascript mapping library.
US County Electoral Map – Land Area vs Population
Posted In: Maps | Uncategorized | Voting
County-level Election Results from 2016
This interactive map shows the election results by county and you can display the size of counties based on their land area or population size.
A little while ago, I made a map (cartogram) that showed the state by state electoral results from the 2016 Presidential Election by scaling the size of the states based on their electoral votes. The idea for that map was that by portraying a state as Red or Blue, your eye naturally attempts to determine which color has a greater share of the total. On a normal election map of the 2016 Election, Red states dominate, especially because a number of larger, less populated states happen to vote Republican. That cartogram changed the size of the states so that large states with low population, and thus low electoral votes tended to shrink in size, while smaller states with moderate to larger populations tended to grow in size. Thus, when your eyes attempt to discern which color prevails, the comparison is more accurate and attempts to replicate the relative ratio of electoral votes for each side.
This map looks at the election results, county by county. An interesting thing to note is that this view is even more heavily dominated by the color red, for the same reasons. Less densely populated counties tend to vote republican, while higher density, typically smaller counties tend to vote for democrats. As a result, the blue counties tend to be the smaller ones so blue is visually less represented than it should be based on vote totals. More than 75% of the land area is red, when looking at the map based on land areas, while shifting to the population view only about 46% of the map is red. Neither of these percentages is exactly correct because each county is colored fully red or blue and don’t take into account that some counties are won by a large percentage and some are essentially tied. However, the population number is certainly closer to reality as Trump won about 48.8% of the votes that went to either Trump or Clinton.
Instructions
This tool should be relatively straightforward to use. Just click around and play with it.
The map has a few different options for display:
• Hide Circles – just shows the county map
• Show land circles – where the area of the circle matches the area of the county itself, though obviously shaped like a circle. The counties are colored red or blue depending on whether Trump or Clinton won more votes in that county.
• Show population circles – where the area of the circle matches the relative population of the county itself. More populated counties will grow larger while less populated counties will shrink. The counties are colored red or blue depending on whether Trump or Clinton won more votes in that county.
• Selecting the No County Overlap checkbox will spread out all of the circles so you can see them all. The total displayed area of the county circles is the same in either land and population view, though if the circles are overlapping, you may see less total colors.
Visualization notes
This was my second attempt at using d3 to generate visualizations. I typically use leaflet to do web-based mapping but I wanted the power of d3 which has functions for the circles to prevent overlapping. This map was inspired by Karim Douieb’s cool visualization of 2016 election results. I modified it in a number of different ways to try to make it more interactive and useful.
This visualization does not actually simulate the collisions between the circles on your browser. It is a bit computationally taxing and causes my computer fan to turn on after awhile. So instead I ran the simulation on my computer and recorded the coordinates for where each circle ended up for each category. Then your browser is simply using d3 transitions to shift positions and sizes of the circles between each of the maps, which is simpler, though with 3142 counties, it can still tax the computer occasionally.
Data and Tools
County level election data is from MIT Election Lab. Population data used is for 2018. The visualization was created using d3 javascript visualization library.
Assembling the USA state-by-state with state-level statistics
Posted In: Maps
Watch the United States assemble state by state based on statistics of interest
Based on earlier popularity of the country-by-country animation, this map lets you watch as the world is built-up one state at a time. This can be done along a large range of statistical dimensions:
• Name (alphabetical)
• abbreviation
• Date of entry to the United States
• State Population (2018)
• Population per Electoral Vote (2018)
• Population per House Seat (2018)
• Land Area (square miles)
• Population Density (ppl per sq mi) (2018)
• State’s Highest Point
• Highest Elevation (ft)
• Mean Elevation (ft)
• State’s Lowest Point
• Lowest Point (ft)
• Life Expectancy at Birth (yrs)
• Median Age (yrs)
• Percent with High School Education
• Percent with Bachelor’s Degree
• Residential Electricity Price (cents per kWh) (2018)
• Gasoline Price ($/gal) Regular unleaded (2019) • State Gross Domestic Product GDP ($Million) (2018)
• GDP per capita (\$/capita)
• Number of Counties (or subdivisions)
• Average Daily Solar Radiation (kWh/m2)
• Birth rate (per thousand population)
• Avg Age of Mother at Birth
• Annual Precipitation (in/yr)
• Average Temperature (deg F)
• These statistics can be sorted from small to large or vice versa to get a view of the US and its constituent states plus DC in a unique and interesting way. It’s a bit hypnotic to watch as the states appear and add to the country one by one.
You can use this map to display all the states that have higher life expectancy than the Texas:
select “Life expectancy”, sort from “high to low” and use the scroll bar to move to the Texax and you’ll get a picture like this:
or this map to display all the states that have higher population density than California:
select “Population density, sort from “high to low” and use the scroll bar to move to the United States and you’ll get a picture like this:
I hope you enjoy exploring the United States through a number of different demographic, economic and physical characteristics through this data viz tool. And if you have ideas for other statistics to add, I will try to do so.
• Population https://en.wikipedia.org/wiki/List_of_states_and_territories_of_the_United_States_by_population
• Educational attainment https://nces.ed.gov/programs/digest/d18/tables/dt18_104.88.asp
• Highest points https://geology.com/state-high-points.shtml
• Life expectancy https://en.wikipedia.org/wiki/List_of_U.S._states_and_territories_by_life_expectancy
• Median Age http://www.statemaster.com/graph/peo_med_age-people-median-age
• Land area https://statesymbolsusa.org/symbol-official-item/national-us/uncategorized/states-size
• Mean elevation https://www.census.gov/library/publications/2011/compendia/statab/131ed/geography-environment.html
• Electricity price https://www.chooseenergy.com/electricity-rates-by-state/
• Gasoline price https://gasprices.aaa.com/state-gas-price-averages/
• GDP https://www.bea.gov/data/gdp/gdp-state
• Sunlight North America Land Data Assimilation System (NLDAS) Daily Sunlight (insolation) for years 1979-2011 on CDC WONDER Online Database, released 2013. Accessed at http://wonder.cdc.gov/NASA-INSOLAR.html on Jun 14, 2019 1:37:15 PM
• Births United States Department of Health and Human Services (US DHHS), Centers for Disease Control and Prevention (CDC), National Center for Health Statistics (NCHS), Division of Vital Statistics, Natality public-use data 2007-2017, on CDC WONDER Online Database, October 2018. Accessed at http://wonder.cdc.gov/natality-current.html on Jun 14, 2019 1:53:58 PM
• Precipitation North America Land Data Assimilation System (NLDAS) Daily Precipitation for years 1979-2011 on CDC WONDER Online Database, released 2013. Accessed at http://wonder.cdc.gov/NASA-Precipitation.html on Jun 26, 2019 3:30:40 PM
• Temperature http://www.usa.com/rank/us–average-temperature–state-rank.htm
The map was created with the help of the open source leaflet javascript mapping library
Assembling the World Country-By-Country
Posted In: Maps
Watch the world assemble country-by-country based on a specific statistic
This map lets you watch as the world is built-up one country at a time. This can be done along the following statistical dimensions:
• Country name
• Population – from United Nations (2017)
• GDP – from United Nations (2017)
• GDP per capita
• GDP per area
• Land Area – from CIA factbook (2016)
• Population density
• Life expectancy – from World Health Organization (2015)
• or a random order
These statistics can be sorted from small to large or vice versa to get a view of the globe and its constituent countries in a unique and interesting way. It’s a bit hypnotic to watch as the countries appear and add to the world one by one.
You can use this map to display all the countries that have higher life expectancy than the United States:
select “Life expectancy”, sort from “high to low” and use the scroll bar to move to the United States and you’ll get a picture like this:
or this map to display all the countries that have higher population density than the United States:
select “Population density, sort from “high to low” and use the scroll bar to move to the United States and you’ll get a picture like this:
I hope you enjoy exploring the countries of the world through this data viz tool. And if you have ideas for other statistics to add, I will try to do so.
Data and tools: Data was downloaded primarily from Wikipedia: Life expectancy from World Health Organization (2015) | GDP from United Nations (2017) | Population from United Nations (2017) | Land Area from CIA factbook (2016)
The map was created with the help of the open source leaflet javascript mapping library
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2020-09-22 10:21:35
|
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|
https://codereview.stackexchange.com/questions/250113/interactive-mandelbrot-set-pictures
|
# Interactive Mandelbrot set pictures
The purpose of this project is to generate an interactive Mandelbrot set. The user can specify the degree of magnification from the command-line and click on the produced picture to magnify the picture at that point.
Here is a data-type implementation for Complex numbers:
public class Complex
{
private final double re;
private final double im;
public Complex(double re, double im)
{
this.re = re;
this.im = im;
}
public double re()
{
return re;
}
public double im()
{
return im;
}
public double abs()
{
return Math.sqrt(re*re + im*im);
}
public Complex plus(Complex b)
{
double real = re + b.re;
double imag = im + b.im;
return new Complex(real, imag);
}
public Complex times(Complex b)
{
double real = re*b.re - im*b.im;
double imag = re*b.im + im*b.re;
return new Complex(real, imag);
}
public Complex divide(Complex b)
{
double real = (re*b.re + im*b.im) / (b.re*b.re + b.im*b.im);
double imag = (im*b.re - re*b.im) / (b.re*b.re + b.im*b.im);
return new Complex(real, imag);
}
public boolean equals(Complex b)
{
if (re == b.re && im == b.im) return true;
else return false;
}
public Complex conjugate()
{
return new Complex(re, -1.0*im);
}
public String toString()
{
return re + " + " + im + "i";
}
}
Here is my program:
import java.awt.Color;
public class InteractiveMandelbrot {
private static int checkDegreeOfDivergence(Complex c) {
Complex nextRecurrence = c;
for (int i = 0; i < 255; i++) {
if (nextRecurrence.abs() >= 2) return i;
nextRecurrence = nextRecurrence.times(nextRecurrence).plus(c);
}
return 255;
}
private static Color[] createRandomColors() {
Color[] colors = new Color[256];
double r = Math.random();
int red = 0, green = 0, blue = 0;
for (int i = 0; i < 256; i++) {
red = 13*(256-i) % 256;
green = 7*(256-i) % 256;
blue = 11*(256-i) % 256;
colors[i] = new Color(red,green,blue);
}
return colors;
}
private static void drawMandelbrot(double x, double y, double zoom) {
StdDraw.enableDoubleBuffering();
Color[] colors = createRandomColors();
int resolution = 1000;
int low = -resolution / 2;
int high = resolution / 2;
double xLowScale = x + zoom*(1.0 * low / resolution);
double xHighScale = x + zoom*(1.0 * high / resolution);
double yLowScale = y + zoom*(1.0 * low / resolution);
double yHighScale = y + zoom*(1.0 * high / resolution);
StdDraw.setXscale(xLowScale, xHighScale);
StdDraw.setYscale(yLowScale, yHighScale);
for (int i = low; i < high; i++) {
for (int j = low; j < high; j++) {
double realPart = zoom*(1.0 * i / resolution) + x;
double imaginaryPart = zoom*(1.0 * j / resolution) + y;
Complex c = new Complex(realPart,imaginaryPart);
int degreeOfDivergence = checkDegreeOfDivergence(c);
Color color = colors[degreeOfDivergence];
StdDraw.setPenColor(color);
double radius = 1.0 / (resolution * 2 / zoom);
}
}
StdDraw.show();
}
public static void main(String[] args) {
double x = Double.parseDouble(args[0]);
double y = Double.parseDouble(args[1]);
int magnifier = Integer.parseInt(args[2]);
double zoom = 1;
drawMandelbrot(x, y, zoom);
while (true) {
if (StdDraw.isMousePressed()) {
x = StdDraw.mouseX();
y = StdDraw.mouseY();
zoom = zoom/magnifier;
drawMandelbrot(x, y, zoom);
}
}
}
}
StdDraw is a simple API written by the authors of the book Computer Science An Interdisciplinary Approach. I checked my program and it works. Here is one instance of it.
Input: 0.5 0.5 10
Output (actually a succession of outputs):
I used paint to show where I clicked.
From my own previous posts, I already know how to improve Complex. In this post, I am solely interested in the improvement of InteractiveMandelbrot. Is there any way that I can improve my program?
# Performance: the Complex class
You've mentioned that you already know how to improve it, but the single biggest performance improvement to this program is removing the Complex class. Perhaps it's sad to say goodbye to that class, but run some performance tests and decide.
On my PC, at the point/zoom 0.5, 0.5, 10, the original code runs in 100 - 110 ms per frame. Excluding drawing time, I removed that and just save the colors to an array. Excluding the first run, which is slower as is usual with Java.
If I write the complex arithmetic inline, without fundamentally changing it, like this:
private static int checkDegreeOfDivergence(double r, double i) {
double a = r, b = i;
for (int j = 0; j < 255; j++) {
if (Math.sqrt(a * a + b * b) >= 2) return j;
double nextA = a * a - b * b + r;
double nextB = a * b + b * a + i;
a = nextA;
b = nextB;
}
return 255;
}
Now it runs in 30 - 40ms per frame. Around 3 times as fast, just by simple refactoring.
The logic can be slightly optimized, but the improvement from this is much less significant.
private static int checkDegreeOfDivergence(double r, double i) {
double a = r, b = i;
for (int j = 0; j < 255; j++) {
if ((a * a + b * b) >= 4) return j;
double nextA = a * a - b * b + r;
double nextB = a * b * 2 + i;
a = nextA;
b = nextB;
}
return 255;
}
• Just wow! It's a great perspective. Thank you very much. – Khashayar Baghizadeh Oct 3 '20 at 22:05
## Comment 1
You are not using the r variable in createRandomColors , so there is nothing random in it.
## Comment 2
if (nextRecurrence.abs() >= 2) return i;
You should use brackets after if, don't try to be smart by writing one-liners like this. It will bite you one day when you misread it or edit it without noticing.
## Comment 3
for (int i = low; i < high; i++) {
for (int j = low; j < high; j++) {
double realPart = zoom*(1.0 * i / resolution)
The calculation zoom * 1.0 / resolution is calculated 3 times in this double for loop, that's for every pixel on screen I think. It might be worth optimizing your calculations by taking out this factor and calculating it just once.
Since it doesn't depend on i or j, you could take this calculation out of the loop entirely and so you would calculate it once per screen instead of 3*millions times.
Likewise, the realPart does not depend on j, so calculate it outside of the j loop to save yourself 999/1000 (approximately) calculations for realPart.
double realPart = zoom*(1.0 * i / resolution) + x;
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2021-07-29 13:23:38
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http://sti.bmj.com/content/78/4/246
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Article Text
Assisting medical students to conduct empathic conversations with patients from a sexual medicine clinic
1. P Henderson,
2. M H Johnson
1. Department of Anatomy, Downing Street, Cambridge CB2 3DY, UK
1. Correspondence to:
Professor Johnson;
mhj{at}mole.bio.cam.ac.uk
## Abstract
Objective: To describe an exercise, the structure and content of which assists medical students to conduct potentially embarrassing conversations concerning sexual health which require expression of empathy, to integrate previous learning, to identify their further learning needs, and to develop and test strategies to meet these needs.
Method: Students’ role play, sequentially, speakers (patients) and listeners (clinical students) in a “carousel,” in which all students are engaged at all times in a sequence of pairings which change at rapid intervals. Half way through the exercise, students reflect on the experience, identify difficulties and successes, and develop and share strategies for experimental use in the second half of the exercise.
Results: Qualitative comments from the written student evaluations are reported.
Conclusions: The exercise provides a formative student centred approach to the integration and further development of previously learnt knowledge and skills of value for promoting sexual health education. It is useful for educators interested in promoting more open and informed learning about sexual health.
• sexual conversations
• sexual health
• empathy
## Statistics from Altmetric.com
We describe a learning approach to the integration of skills, knowledge, and attitudinal development in the context of a potentially difficult clinical situation concerning sexual health. The exercise has been developed over a 10 year period, with 20 third year preclinical undergraduates in each year on a course, the organisation, student selection, staffing, and assessment of which have been described previously.1–5 Sex, gender, reproduction, and sexuality form one part of the course syllabus of lectures, seminars, workshops, and projects being offered in these areas.3,4 In general, exercises of the sort described here precede theoretical and academic work. However, we have developed this exercise for use when students have worked together intensively over two terms to develop communication skills, increase awareness of their own attitudes and values, and increase their understanding of relevant sex and gender issues. This previous work includes practising communication skills in pairs2 and with actor patients with video feedback. They have also had opportunities to explore and use sexual language (vernacular, idiomatic, and slang) in several contexts, and to discuss sexual behaviour which they believe falls within or outside social norms.1,3,4 They have been given the opportunity to privately review their own sexual development and gender identity, and shared what they will with a partner. The exercise described here encourages them to integrate their previous learning, skills, and attitudinal work as a prelude to direct encounters with patients.
## METHOD
The exercise is presented to the students with the following explicit aims.
1. To use clinical scenarios to explore how you might react professionally to sexual situations
2. To attempt to empathise with patients in particular situations through role plays
3. To identify what responses/behaviours might be helpful to you and to the patient and why
4. To try out some of these behaviours.
The exercise lasts for about 2 hours and it is useful to have a break half way through as the role plays are very intense. One (or two) facilitators supply cards outlining scenarios (see box) plus, with the appropriate cards, a cervical diaphragm, condoms, femidoms, an IUCD, and bulldog clips. The basic organisation of the exercise uses a “carousel” format.6
### Examples of role play scenarios
Some scenarios are marked “for males,” others “for females,” others work equally well for either sex. The first scenario is described in detail and the rest are sketched.
You are:
1. A young woman who is due to have an education session about how to fit a cervical diaphragm. You are anxious about what this involves as you have heard it is very painful. You want to ask the clinical student to explain in detail to you what exactly your cervix is and what will happen to you. You have a diaphragm in your pocket which was given to you at an earlier visit, but you have not experimented with putting it in. Now is a chance to talk about this situation.
2. A young homosexual man who has only just “come out,” but doesn’t know how to use a condom.
3. A 53 year old woman who has started to experience considerable pain having intercourse.
4. A man in his fifties who has been having difficulties passing urine and who has been told that he may have an enlarged prostate. The diagnosis may involve a rectal examination.
5. A woman who gains her only sexual thrill from masturbating herself. You want to find out about different ways of masturbating and which is most stimulating.
6. A male with a small nodule on the left testis and anxious about it.
7. A female who is worried that your vagina smells badly and will put men off.
8. A woman interested in having an IUD fitted.
9. A male of 20 who has been worried since school friends made fun of you in the showers because your penis bends over to the left when it is stiff.
10. A person who gains great sexual excitement from having your sexual partner attach bulldog clips to your nipples, penis, and scrotum (man) or nipples, labia, and clitoris (woman). If they are then pulled on or squeezed the pain is exquisitely sexual. However, you are now rather bruised and worried you have done permanent damage but you feel a deep need to go on doing it.
11. A man or woman who has a boyfriend who has asked you to perform oral sex for him but you have not done this before. You want to know what you should do with his “cum.” Is it safe to swallow or should you spit it out?
12. A male or female who is 13 and has begun a sexual relationship with a man of 20. Your parents have found out and are angry with you. They have sent you to the doctor for some contraceptive advice.
13. A 21 year old woman who has been married for 3 years. You have been having an affair for the past 3 months, and have just done a pregnancy test and found out you are pregnant, and both you and your husband will know it is not his. You want the baby, but have come to ask about having an abortion.
14. A male 18 year old rent boy who uses a cocktail of drugs. You have come because you are worried about HIV as you usually have unprotected sex.
The organisation of the role play should take into account the need to give clear instructions, to manage the timing, to create a “professional” atmosphere so that students take the process seriously, and to provide support for those who are overcome with embarrassment or incompetence. The facilitators place 10 chairs in a circle facing outwards, well spaced to make maximum use of the room and so that sound spillover between neighbouring chairs is not a problem. A further 10 chairs are placed opposite to them facing inwards.
The students are divided into two groups of 10. Facilitators explain that one group of 10 will role play patients. Each of these is given an envelope containing a card with a scenario on it and any props necessary. After they have opened and read their scenarios, each is asked to note down their immediate responses. They then take 5 minutes in silence to get into role. As this is an empathy exercise, the more they can get into role, the more effective the exercise will be. All scenarios begin with the following instruction:
“Read the situation below and then devise a persona with whom to empathise. You can develop this persona during the three runs of the role play but start now, using as prompts the following questions:
• How old are you?
• Where do you live?
• With whom: what are their names?
• What is your life style?
• What is your background and personal history?
• What are names of the important people in your life?”
When ready to begin the role play carousel, each of them sits on an inward facing chair, mixing the order so that men are spread among women.
The other 10 are to role play clinical students for whom patients have been organised by the sexual medicine clinic so as to gain experience. They are invited to think themselves into the situation and prepare mentally: “How are you going to initiate the session? How might you structure it?” They each sit opposite one of the patients at random, mixing genders as far as possible.
Each pair then has 5–7 minutes of contact. When the facilitator calls time, they stop immediately wherever they are in the exchange. Each “clinical student” then moves one place to the right for a second 5–7 minutes with a new patient, and then to the right again a further 5–7 minutes with a third patient. Meanwhile, the patient remains in the same role for each new consultation with a different “doctor” and does not break role until all three periods of 5–7 minutes are over.
Once this first set of exchanges is complete, students “de-role” actively by moving around, and declaring themselves not to be the person or role they have been playing. Then “clinical students” form pairs and “patients” form pairs for 10 minutes to consider these questions:
• What was easy?
• What presented difficulties for me?
• Did any of my attitudes or assumptions that came out in the process surprise me?
• Were my reactions professional?
These pair reviews are followed by a plenary session with facilitators, which moves from reviewing their feelings and attitudes to identifying specific behaviours that might or might not be useful professionally to help them and the patients cope with sexual subject matter. We encourage them to describe how these behaviours will help deal with the feelings and attitudes raised. This discussion aims to turn behaviours into strategies and to encourage the students to adapt and personalise them.
After a short tea break, students swap roles and set up as before with new patient cards, and the role play carousel runs for a further 21 minutes. Students then spend 15 minutes in a group of four (two patients and two students per group) to identify, with specific examples, what worked and why. A final plenary session ensures that extra learning from the second sequence is shared, and students consider how they may apply it when they are clinical students.
## RESULTS
Student written evaluations provide an indicator of their learning.5 Almost all comment on how effectively the structure of the exercise contributes to their learning, indicating how good their analytical grasp of learning methodologies had become during the year, and several make suggestions for change:
“It was very useful that we each got three goes at talking to patients, as this allowed us to learn from our mistakes very quickly and to vary our strategy.” “The day would not have worked as well if it had been towards the beginning of the course . . . in my future career, I will have to deal with matters of a sexual nature in a much more exposed, hazardous climate. This workshop is an extremely good basis upon which to build my strategies to deal with sexual issues effectively.” “The role play was incredibly useful and . . . showed very well what strategies worked better to make the patient feel more at ease. It was also very useful to see three doctors, since that made it much easier to see what worked or not.” “It was very rewarding trying to analyse what it was they [clinical students] had done which made me let go and feel free to speak easily.” “I would have liked to have heard some individual feedback, on how my patients felt about ME . . . this would obviously have taken more time, but to have heard (for example) what the three best and improvable aspects of my approach were—would have been of more use to me.”
They were also commenting on how the learning strategy also informed their thinking about possible consultation strategies:
“By discussing our learning following the exercise in small groups we were able to share and learn from each other’s experiences. It was also reassuring to find that we had had similar difficulties. This may suggest that it could be important to present yourself to the patients as just another person, rather than as some austere professional figure.” “Experience will help me to deal with such problems in a more professional manner, but the form of today’s workshop allowed me to consider the position from which I am starting and therefore helped me to understand my own reactions and emotions.” “A big challenge for me but I feel that I gained a lot of useful insight.”
Most also expressed the view that they learnt very different things from being both patients and medical students. Playing patient roles taught them very powerfully about what they needed from a consultation:
In contrast, playing the clinical student role informed them about their own needs and limitations, both personal and professional:
“I always thought I was liberal minded but talking to people about their sexual experiences made me realise that I am not as open minded as I might like to think.” “It brought home to me how important it is to try not to bring your personal opinions into a consultation, however difficult. I can’t just say don’t do it unless there is medical reason.” “The most important learning for me from this exercise is in knowing my own limitations, and dealing with them before the situation becomes too difficult. I found that I did have great difficulty listening sensitively to the patients’ talking about their sexual health problems, and this probably was because I found it embarrassing.” “If I now get into a situation that I don’t think I can handle because of personal issues then I have a duty to get the patient someone who might be better at dealing with them than me.” “I was confronted with the dilemma of whether to disclose my sexuality to a patient. I was questioned whether my motives for this were self directed or patient directed, but I genuinely believe that if I had a sex related problem which could be better answered by another gay man, I would value advice more from a gay doctor. I don’t think it’s fair that Asian or female doctors, for example, are able to benefit from their minority’ status by offering empathy, whereas I’m apparently not. I still don’t know what to do about this dilemma, and it alarmed me how quickly the problem, which I’d hoped to be able to avoid, arose in this context. More seriously, I’m not sure what to do if a patient asks me whether I’m gay. I don’t have a problem answering the question honestly, and in order not to do so I’d have to lie or avoid the question, both of which would damage the relationship with the patient. But then telling the truth might. I’m having real problems with this one; it just goes round and round in my head. I think I need some help coming to a suitable answer. Any ideas? By the way I’m grateful that the issue was brought to my attention by the workshop rather than by a patient! At least this way I can come to a working solution by the time it matters.” (This evaluation was followed up by facilitators) “I think that I would find it inappropriate for a doctor to refer to him/herself to make me feel less embarrassed because that would remove the protective professional barrier.” “I felt a key factor was gauging the right level for the patient’s worries . . . or gauging their feelings and level of embarrassment in discussing sexual matters. It was uncomfortable as a middle aged woman with an embarrassing pain to hear people use explicit clinical phrases and blunt personal questions, but as a young sexually confident woman another student felt she was being medicalised and treated as strange by the way her doctors’ referred to her problem as if she must be embarrassed.” “A lot of the strategies seemed to be good for some patients and terrible for others . . . for instance with a patient who just wanted an IUD, I was too tentative and too reassuring, because I’d just had a patient who needed that approach. I need a beginning that is suitable for all problems, embarrassing or not. Using the word personal’ instead of `embarrassing’ may be of some help here.”
It was interesting that the conditions developed in the group enabled their mutual learning about sexual diversity and their own difficulties to extend into the processing after the carousel itself:
“One has to be careful what you assume, as what you might find strange is normal for someone else. I said that I found something very hard to deal with and gave a story to illustrate, but my partner was then brave enough later to say that they enjoy the practice I had just said was abhorrent. I really respected them for this.”
## DISCUSSION
Medical education in the United Kingdom is undergoing considerable change, driven largely by the recommendations of the education committee of the General Medical Council,7 which encourages more student centred and problem based learning approaches as well as requiring attitudinal issues to be addressed. Sexual health is a sensitive area for both skills and attitude development. Some approaches to the issue of skills teaching in this area have been reported.8,9 We have focused on attitudinal education and have been developing use of structured experiential work as one approach, of particular value where strong emotional and personal issues arise in medicine.1 The provision of a safe environment in which students can express concerns and then develop strategies for addressing them is an important component of this approach. Structured reflection on values, attitudes, and emotions can precede or follow other sorts of informational or skills based learning.5 Here we use such an approach as an integrating device, although the same approach as described here can be adapted for use early on in a course to raise issues for consideration (see, for example, Johnson and Henderson1).
This intensive and challenging exercise yields rich learning about attitudes, behaviour, and values. It works best when the group is well formed, and meets within an explicit contract to support experiential learning by responsible behaviour. It requires facilitators who can themselves talk easily about sexual matters, and can support those students who find it difficult or who become self critical as they discover that they have more difficulties in applying previous learning than they anticipated. It is a sound preparation for initial sessions in a GUM clinic before exposure to patients and the performance pressure which that experience can bring. Details could easily be adapted for other embarrassing or otherwise difficult exchanges.
The experiential approach used in this exercise is particularly suited to the integration by medical students of the attitudinal, knowledge, and skills elements of training. However, surprisingly little use of this approach has been reported in the United Kingdom.1,3,4,10 considering the emphasis being placed by the education committee of the GMC on such learning.
## Acknowledgments
We thank our students for permission to quote from their evaluations and Pat Tate for her useful comments on a draft manuscript.
STATEMENTS
Both authors have developed, applied, and tested this version of the carousel for the purposes described here. No paper resembling the enclosed article has been or will be published except in Sexually Transmitted Infections. No funding is involved and so there are no conflicts of interest.
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2017-08-21 21:52:10
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https://www.physicsforums.com/threads/latex-appendix.378894/
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# LaTeX Appendix
1. ### latentcorpse
I need to include a single appendix in my honours project. The appendix will be the last bit before the bibliography.
I have
\appendix
\chapter{Deriving the Einstein equations for the .... Spacetimes}
This is causing a couple of problems for me:
(i) In the table of contents, there is a line that says "Appendix" and then underneath that it says "A". However, the word "Appendix" is at the bottom of my first contents page and the letter "A" is at the top of the next page of contents. Is there any way to sort this out?
(ii) Even though I have only one appendix, is it the norm to call it "Appendix A" rather than just "Appendix"?
(iii) I need to give this appendix a name such as "Deriving the Einstein equations for the .... Spacetimes". Obviously this is a big title, if I put it in the \chapter{} brackets then it prints really big and takes up 3 lines in a big font - is there any way to make it smaller?
2. ### nelufar
32
First of all I will suggest that if you have only one appendix there is no need to say "A", you can just keep the title.
Secondly, there is no way that in TOC you can shift the word "Appendix" to next page, as the spacing between two lines in TOC is defined by your style file. Playing around with your style file will change over all formatting.
Also for reducing the font of the appendix title try using following command "\chapter{\small{.........}}". I guess this might work.
3. ### krupashah
3
here AppendixA is one new txt file which is include k
so in main file write the below clde.
\appendix
\flushbottom
\include{AppendixA}
\flushbottom
In AppendixA file write below code...
\chapter{Acronyms}
SO we get Chapter name as Acronyms in our report or article n also in index...
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2015-03-06 06:03:34
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https://ncatlab.org/nlab/show/nothing
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Contents
philosophy
# Contents
## Idea
According to Science of Logic, the opposite of being.
Dasein
becoming :nothing$\;\;\;\dashv$being: ceasing
## References
Last revised on November 26, 2014 at 21:29:07. See the history of this page for a list of all contributions to it.
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2023-03-28 15:59:01
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http://sci-gems.math.bas.bg/jspui/handle/10525/2416
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Please use this identifier to cite or link to this item: http://hdl.handle.net/10525/2416
Title: Data Extraction from Carte Du Ciel Triple Images Authors: Laskov, LaskoTsvetkov, Milcho Keywords: Astrographic MapsCarte du CielScientific HeritageImage ProcessingPattern Recognition Issue Date: 2013 Publisher: Institute of Mathematics and Informatics Bulgarian Academy of Sciences Citation: Serdica Journal of Computing, Vol. 7, No 4, (2013), 317p-332p Abstract: Carte du Ciel (from French, map of the sky) is a part of a 19th century extensive international astronomical project whose goal was to map the entire visible sky. The results of this vast effort were collected in the form of astrographic plates and their paper representatives that are called astrographic maps and are widely distributed among many observatories and astronomical institutes over the world. Our goal is to design methods and algorithms to automatically extract data from digitized Carte du Ciel astrographic maps. This paper examines the image processing and pattern recognition techniques that can be adopted for automatic extraction of astronomical data from stars’ triple expositions that can aid variable stars detection in Carte du Ciel maps. URI: http://hdl.handle.net/10525/2416 ISSN: 1312-6555 Appears in Collections: Volume 7 Number 4
Files in This Item:
File Description SizeFormat
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2023-01-28 01:03:38
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http://bib-pubdb1.desy.de/collection/PUB_FS-ATTO-20170403?ln=en
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FS-ATTO
2017-09-1416:06 [PUBDB-2017-10786] Journal Article et al Application of Matched-Filter Concepts to Unbiased Selection of Data in Pump-Probe Experiments with Free Electron Lasers Applied Sciences 7(6), 621 - (2017) [10.3390/app7060621] Pump-probe experiments are commonly used at Free Electron Lasers (FEL) to elucidate the femtosecond dynamics of atoms, molecules, clusters, liquids and solids. Maximizing the signal-to-noise ratio of the measurements is often a primary need of the experiment, and the aggregation of repeated, rapid, scans of the pump-probe delay is preferable to a single long-lasting scan. [...] OpenAccess: PDF PDF (PDFA); 2017-09-1416:03 [PUBDB-2017-10785] Journal Article et al Vectorial optical field reconstruction by attosecond spatial interferometry Nature photonics 11(6), 383 - 389 (2017) [10.1038/nphoton.2017.73] An electrical pulse E(t) is defined completely by its time-dependent amplitude and polarization direction. For opticalpulses the manipulation and characterization of the light polarization state is fundamental because of its relevance inseveral scientific and technologicalfields. [...] Fulltext: PDF PDF (PDFA); 2017-09-1416:02 [PUBDB-2017-10784] Journal Article et al Attosecond Electron Dynamics in Molecules Chemical reviews 117(16), 10760 - 10825 (2017) [10.1021/acs.chemrev.6b00453] Advances in attosecond science have led to a wealth of important discoveries in atomic, molecular, and solid-state physics and are progressively directing their footsteps toward problems of chemical interest. Relevant technical achievements in the generation and application of extreme-ultraviolet subfemtosecond pulses, the introduction of experimental techniques able to follow in time the electron dynamics in quantum systems, and the development of sophisticated theoretical methods for the interpretation of the outcomes of such experiments have raised a continuous growing interest in attosecond phenomena, as demonstrated by the vast literature on the subject. [...] Fulltext: PDF PDF (PDFA); 2017-09-1415:59 [PUBDB-2017-10783] Journal Article et al The ELI-ALPS facility: the next generation of attosecond sources Journal of physics / B 50(13), 132002 - (2017) [10.1088/1361-6455/aa6ee8] This review presents the technological infrastructure that will be available at the Extreme Light Infrastructure Attosecond Light Pulse Source (ELI-ALPS) international facility. ELI-ALPS will offer to the international scientific community ultrashort pulses in the femtosecond and attosecond domain for time-resolved investigations with unprecedented levels of high quality characteristics. [...] OpenAccess: PDF PDF (PDFA); 2017-09-1415:55 [PUBDB-2017-10782] Journal Article et al Time-Resolved Measurement of Interatomic Coulombic Decay Induced by Two-Photon Double Excitation of Ne 2 Physical review letters 118(3), 033202 (2017) [10.1103/PhysRevLett.118.033202] The hitherto unexplored two-photon doubly excited states [Ne*$(2p−^13s)]_2$ were experimentallyidentified using the seeded, fully coherent, intense extreme ultraviolet free-electron laser FERMI. Thesestates undergo ultrafast interatomic Coulombic decay (ICD), which predominantly produces singly ionizeddimers. [...] Fulltext: PDF PDF (PDFA); 2017-09-1415:52 [PUBDB-2017-10781] Journal Article et al Slow Interatomic Coulombic Decay of Multiply Excited Neon Clusters Physical review letters 117(27), 276806 (2016) [10.1103/PhysRevLett.117.276806] Ne clusters (∼5000 atoms) were resonantly excited $(2p→3s)$ by intense free electron laser (FEL)radiation at FERMI. Such multiply excited clusters can decay nonradiatively via energy exchange betweenat least two neighboring excited atoms. [...] Fulltext: PDF PDF (PDFA); 2017-09-0707:54 [PUBDB-2017-10449] Journal Article et al Attosecond chronoscopy of electron scattering in dielectric nanoparticles Nature physics 13(8), 766 - 770 (2017) [10.1038/nphys4129] The scattering of electrons in dielectric materials is central to laser nanomachining$^1$, light-driven electronics$^2$ and radiation damage$^{3, 4, 5}$. Here, we demonstrate real-time access to electron scattering by implementing attosecond streaking spectroscopy on dielectric nanoparticles: photoelectrons are generated inside the nanoparticles and both their transport through the material and photoemission are tracked on an attosecond timescale [...] Restricted: PDF PDF (PDFA);
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2017-12-13 03:31:50
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https://www.scilit.net/article/e2c994bc2d5d5d696098328528f0f2a5
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### Fixed Points That Are Zeros of a Given Function
Francesca Vetro
Published: 4 May 2021
Advances in Metric Fixed Point Theory and Applications pp 157-182; doi:10.1007/978-981-33-6647-3_8
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2021-05-12 02:58:30
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https://ai.stackexchange.com/questions/35204/is-attention-always-better-then-an-rnn-cnn
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# Is attention always better then an RNN/CNN?
We've all read the attention is all you need paper, but is it really all you need? Can you effectively replace any RNN/CNN with an attention transformer and see better results?
• Note that some LSTM architectures (e.g. for machine translation) that were published before transformers (and its attention mechanism) already used some kind of attention mechanism. So, the idea of "attention" already existed before the transformers. So, I think you should edit your post to clarify that u're referring to the transformer rather than the general idea of attention, if that's really the case. Having said that, we have had a few similar questions in the past, like this, so you might want to look at them and then reviewing your question.
– nbro
Apr 14 at 9:52
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2022-06-25 13:58:39
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http://physics.stackexchange.com/questions/9000/why-is-mass-the-quadratic-term-in-a-lagrangian/9002
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# Why is mass the quadratic term in a Lagrangian?
Why is mass the quadratic term in a Lagrangian?
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I think your Question is asking about how the Correspondence Principle applies in this particular instance. Is that correct? – Peter Morgan Apr 22 '11 at 13:50
This question is ambiguous--- do you mean for particles or for fields? You got answers for both, but it is not clear what you are asking at all. – Ron Maimon Jan 5 '12 at 16:36
I'm not sure if this is the sort of answer you want, but here goes.
Mass, by definition, is the thing in $F=ma$. That is, it's the coefficient in front of the acceleration in the equation of motion. If you build a Lagrangian out of terms involving a coordinate $x$ and its derivative $\dot x$, and then work out the Euler-Lagrange equations, the only way to get a term of the form $m\ddot x$ at the end is to start with a term of the form ${1\over 2}m\dot x^2$ in the Lagrangian.
That's the classical-mechanics answer. If you were looking for a field-theory answer instead, the details are different, but the idea is the same. Think about how you expect mass to show up in the field equation, and work out what term in the original Lagrangian will give rise to the appropriate expression when you use the Lagrangian to derive the field equation.
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I don't think it's quite right to define mass by $F=ma$. If we take the (admittedly imprecise) definition of a force as "Anything that can change the measured velocity of an object.", then we don't know a priori that the relation between force and acceleration will be $F=ma$. For example, if $F=m\dot{a}$, then this $F$ still changes the velocity of the object, and so would still be considered a force. Newton's Second Law has significant physical significance; it is not simply the definition of mass. – Jonathan Gleason Mar 14 '13 at 20:18
As a matter of fact, in what we call "non-inertial frames", the relation between force and acceleration will not be of this form. If anything, Newton's second law provides us with a definition of an inertial frame: "Any frame in which $F=ma$.", and then Newton's second Law could be taken to be the statement "Inertial frames exist.", so that this definition of an inertial frame isn't completely useless. – Jonathan Gleason Mar 14 '13 at 20:21
Take the Lagrangian with only the kinetic and quadratic terms. Find the wave equation and propagator and you'll see that they correspond to those of a free relativistic particle with mass squared equal to the quadratic coefficient. So the interpretation is correct in free field theory.
Adding higher order terms doesn't change this interpretation, since the higher order terms correspond to interactions.
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The mass is a quadratic term in a Lagrangian because it is the Lagrangian density, the Lagrangian per unit of volume. The Lagrangian itself is obtained by integrating over the volume which contains the field. The "classical" relation is.
$H ~-~pv~=~-L$
These integrated quantities, the Hamiltonian $H$, the Lagrangian $L$ and the term $pv$ transform like.
$\begin{array}{lll} H & \mbox{transforms as} & \gamma \\ pv & \mbox{transforms as} & \beta^2\gamma \\ L & \mbox{transforms as} & 1/\gamma \\ \end{array}$
The volume of a wave-functions transforms like $1/\gamma$ due to Lorentz contraction. So, the densities become higher by a factor $\gamma$, hence the Hamiltonian density ${\cal H}$, the Lagrangian density ${\cal L}$ and the density of the $pv$ term transform like.
$\begin{array}{lll} \mathcal{H} & \mbox{transforms as} & \gamma^2 \\ \mathcal{pv} & \mbox{transforms as} & \beta^2\gamma^2 \\ \mathcal{L} & \mbox{transforms as} & "1" \\ \end{array}$
The corresponding relation of the densities transforms like the basic energy/momentum relation.
${\cal H}\ -\ {\cal pv}\ =\ -{\cal L} \qquad \mbox{transforms as} \qquad E^2-p^2\ =\ m^2$
We see that the Lagrangian density is the same in all reference frames. It is a Lorentz scalar. This makes the Lagrangian density a fundamental quantity in quantum field theory. The Standard Model of physics is based on the Lagrangian density which in quantum physics is generally called just the Lagrangian, without the density.
The "equations of motion" are based on the derivatives of the Lagrangian density which is a Lorentz scalar. This assures that the whole Standard Model of physics transforms in the right way, that is, the laws of physics are the same in every reference frame.
Regards, Hans
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Welcome to physics SE. You don't look a day over 85. – Carl Brannen Apr 23 '11 at 5:01
@Carl. Hi Carl, nice to see you here. Thank you for your flattering words :^) – Hans de Vries Apr 23 '11 at 14:23
For a relativistic particle (free or in an external filed), the Lagrangian contains mass differently, not in a "quadratic" way.
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Well, this is because $p^2=m^2$, well known relativistic relation, where p is 4-momentum of a particle, and m is mass. Take free Lagrangian for some classical field and then derive classical equation of motion out of it. Any such equation will be consistent with $p^2=m^2$ (you can see this by doing Fourier transform into p-space), and to keep this condition, you interpret m from term $m^2\phi^2$ as mass of particle.
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For the free quantum field, the quadratic term determines that the energy-momentum 4-vector observable of a single-particle state in a single fourier mode would be on the forward mass-shell instead of on the forward light-cone. That is, $E^2+\mathbf{p}^2=m^2$ is a constant, which is algebraically of the same form as the relativistic mass-energy-momentum relationship. [Note, however, that fourier modes are strictly speaking an improper limit in quantum field theory.]
Again for the free quantum field, but in terms of QFT understood as a stochastic formalism for field observables instead of in terms of a particle interpretation, the two-point correlation function $C(x-y)=\left<0\right|\hat\phi(x)\hat\phi(y)\left|0\right>$ satisfies the classical Klein-Gordon field equation, where we can discuss energy-momentum density.
More abstractly, one could take mass, or inertia, to denote a generalized "resistance" of a given simple evolution to a given deformation of the background or to the introduction of a new force law. In these terms, every constant term in a Lagrangian is part of a multi-dimensional description of what the response of an initial system would be to any given additional term in the Lagrangian. The mass term is singled out as the lowest order component of the inertia.
There seem to me to be a surprising number of ways in which this Question can be taken. I decided only after a while that the Question is useful enough to obviate the lack of clarity. For me it's only because of the QFT tag that the Question becomes productive.
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2015-02-28 23:17:17
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http://mathoverflow.net/questions/84805/integrated-colored-gaussian-noise/84808
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# Integrated colored Gaussian noise
Assume we have a colored Gaussian process $z_t$, with an autocorrelation function $cov(z_t,z_s)$ given by an analytical function $\alpha(t,s)$ (if it helps, one can assume that $\alpha(t,s) = \kappa e^{-w(t-s)}$). Consider now a process defined by
$Z_t := \int_0^t z_s ds$
Now, my 3 questions:
• is $Z_t$ well-defined?
• if so, is $d Z_t = z_t dt$ true in any sense?
• what is the quadratic variation of $Z_t$?
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Q1: Rather yes. If we assume that function $w$ is not crazy, e.g. $C^1$, then there exists a continuous version of $z$ and the integral can be computed path-by-path using the Lebesgue (or even Riemann) integral theory.
Q2:Under assumption above $Z$ has paths of the finite variation. Hence there exists the Stieltjes integral (for almost any path) and for any measurable function $f$ one have $\int_a^b f(t) dZ_t = \int_a^b f(t) z_t dt.$
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2016-05-26 20:49:34
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https://www.physicsforums.com/threads/stereographic-projection-in-de-sitter-cosmological-model.637862/
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Stereographic projection in de Sitter cosmological model
1. Sep 22, 2012
We know stereographic projection is conformal but it isn't isometic and in general relativity it can not be used because in this theory general transformations must be isometric. But de sitter in his model (1917) used it (stereographic projection) to obtain metric in static coordinates. How can it be explained
Last edited: Sep 22, 2012
2. Sep 22, 2012
bcrowell
Staff Emeritus
Not true. In GR, any change of coordinates is legal as long as it's a diffeomorphism. There is no additional requirement.
In GR, when you do a change of coordinates, you change both the coordinates and the elements of the metric tensor itself. The result is that everything automatically still remains consistent. You're still describing the same spacetime, and it's still a solution to the field equations. All you've done is relabel everything. As a simple exampls, if you take Minkowski space and rescale all the coordinates by a factor of 1/2, and the metric was (+1,-1,-1,-1) in the original coordinates, then the metric in the new coordinates is (+4,-4,-4,-4).
When you talk about things like conformal transformations, you're not talking about a change of coordinates. It's more than a relabeling. For example, you can define a conformal transformation like $g\rightarrow \Omega^2 g$, while still leaving all the points fixed and describing them with the same coordinates. Or, alternatively, you can define conformal transformations that send points to other points, while leaving the metric the same. (This is how people typically think about conformal transformations in the complex plane.)
3. Sep 22, 2012
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2018-01-23 14:13:50
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http://mathonline.wikidot.com/algebras-xy-is-quasi-invertible-iff-yx-is-quasi-invertible
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Algebras - xy is Quasi-Invertible IFF yx is Quasi-Invertible
Algebras - xy is Quasi-Invertible IFF yx is Quasi-Invertible
Proposition 3: Let $\mathfrak{A}$ be an algebra and let $x, y \in \mathfrak{A}$. Then: a) $xy$ is left quasi-invertible if and only if $yx$ is left quasi-invertible. b) $xy$ is right quasi-invertible if and only if $yx$ is right quasi-invertible.
• Proof of a) Suppose that $xy$ is left quasi-invertible. Let $z$ be the left quasi-inverse of $xy$. Then $z \circ (xy) = 0$, that is:
(1)
\begin{align} \quad z + xy - zxy = 0 \end{align}
• Multiplying the above equation on the left by $y$ gives us:
(2)
\begin{align} \quad yz + yxy - yzxy = 0 \end{align}
• And multiplying the above equation on the right by $x$ gives us:
(3)
\begin{align} \quad yzx + yxyx - yzxyx &= 0 \\ \quad yzx -yzx(yx) + yxyx &= 0 \quad (*) \end{align}
• We claim that $(yzx - yx)$ is a left quasi-inverse of $yx$. To see this, observe that:
(4)
\begin{align} \quad (yzx - yx) \circ (yx) &= (yzx - yx) + (yx) - (yxz - yx)(yx) \\ &=yzx -yxz(yx) + yx(yx) \\ & \overset{(*)} = 0 \end{align}
• Thus $yx$ is left quasi-invertible and $(yzx - yx)$ is a left quasi-inverse of $yx$. The converse argument is essentially identical. $\blacksquare$
• Proof of b) Suppose that $xy$ is right quasi-invertible with quasi-inverse $z$. Then $xy \cdot z = 0$. It can be shown (similarly to above) that then $yzx - yx$ is a right quasi-inverse of $yx$ and of course, the converse follows immediately. $\blacksquare$
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2022-08-17 23:07:29
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https://en.wikipedia.org/wiki/Sahlqvist_formula
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# Sahlqvist formula
In modal logic, Sahlqvist formulas are a certain kind of modal formula with remarkable properties. The Sahlqvist correspondence theorem states that every Sahlqvist formula is canonical, and corresponds to a first-order definable class of Kripke frames.
Sahlqvist's definition characterizes a decidable set of modal formulas with first-order correspondents. Since it is undecidable, by Chagrova's theorem, whether an arbitrary modal formula has a first-order correspondent, there are formulas with first-order frame conditions that are not Sahlqvist [Chagrova 1991] (see the examples below). Hence Sahlqvist formulas define only a (decidable) subset of modal formulas with first-order correspondents.
## Definition
Sahlqvist formulas are built up from implications, where the consequent is positive and the antecedent is of a restricted form.
• A boxed atom is a propositional atom preceded by a number (possibly 0) of boxes, i.e. a formula of the form ${\displaystyle \Box \cdots \Box p}$ (often abbreviated as ${\displaystyle \Box ^{i}p}$ for ${\displaystyle 0\leq i<\omega }$).
• A Sahlqvist antecedent is a formula constructed using ∧, ∨, and ${\displaystyle \Diamond }$ from boxed atoms, and negative formulas (including the constants ⊥, ⊤).
• A Sahlqvist implication is a formula AB, where A is a Sahlqvist antecedent, and B is a positive formula.
• A Sahlqvist formula is constructed from Sahlqvist implications using ∧ and ${\displaystyle \Box }$ (unrestricted), and using ∨ on formulas with no common variables.
## Examples of Sahlqvist formulas
${\displaystyle p\rightarrow \Diamond p}$
Its first-order corresponding formula is ${\displaystyle \forall x\;Rxx}$, and it defines all reflexive frames
${\displaystyle p\rightarrow \Box \Diamond p}$
Its first-order corresponding formula is ${\displaystyle \forall x\forall y[Rxy\rightarrow Ryx]}$, and it defines all symmetric frames
${\displaystyle \Diamond \Diamond p\rightarrow \Diamond p}$ or ${\displaystyle \Box p\rightarrow \Box \Box p}$
Its first-order corresponding formula is ${\displaystyle \forall x\forall y\forall z[(Rxy\land Ryz)\rightarrow Rxz]}$, and it defines all transitive frames
${\displaystyle \Diamond p\rightarrow \Diamond \Diamond p}$ or ${\displaystyle \Box \Box p\rightarrow \Box p}$
Its first-order corresponding formula is ${\displaystyle \forall x\forall y[Rxy\rightarrow \exists z(Rxz\land Rzy)]}$, and it defines all dense frames
${\displaystyle \Box p\rightarrow \Diamond p}$
Its first-order corresponding formula is ${\displaystyle \forall x\exists y\;Rxy}$, and it defines all right-unbounded frames (also called serial)
${\displaystyle \Diamond \Box p\rightarrow \Box \Diamond p}$
Its first-order corresponding formula is ${\displaystyle \forall x\forall x_{1}\forall z_{0}[Rxx_{1}\land Rxz_{0}\rightarrow \exists z_{1}(Rx_{1}z_{1}\land Rz_{0}z_{1})]}$, and it is the Church-Rosser property.
## Examples of non-Sahlqvist formulas
${\displaystyle \Box \Diamond p\rightarrow \Diamond \Box p}$
This is the McKinsey formula; it does not have a first-order frame condition.
${\displaystyle \Box (\Box p\rightarrow p)\rightarrow \Box p}$
The Löb axiom is not Sahlqvist; again, it does not have a first-order frame condition.
${\displaystyle (\Box \Diamond p\rightarrow \Diamond \Box p)\land (\Diamond \Diamond q\rightarrow \Diamond q)}$
The conjunction of the McKinsey formula and the (4) axiom has a first-order frame condition (the conjunction of the transitivity property with the property ${\displaystyle \forall x[\forall y(Rxy\rightarrow \exists z[Ryz])\rightarrow \exists y(Rxy\wedge \forall z[Ryz\rightarrow z=y])]}$) but is not equivalent to any Sahlqvist formula.
## Kracht's theorem
When a Sahlqvist formula is used as an axiom in a normal modal logic, the logic is guaranteed to be complete with respect to the elementary class of frames the axiom defines. This result comes from the Sahlqvist completeness theorem [Modal Logic, Blackburn et al., Theorem 4.42]. But there is also a converse theorem, namely a theorem that states which first-order conditions are the correspondents of Sahlqvist formulas. Kracht's theorem states that any Sahlqvist formula locally corresponds to a Kracht formula; and conversely, every Kracht formula is a local first-order correspondent of some Sahlqvist formula which can be effectively obtained from the Kracht formula [Modal Logic, Blackburn et al., Theorem 3.59].
## References
• L. A. Chagrova, 1991. An undecidable problem in correspondence theory. Journal of Symbolic Logic 56:1261–1272.
• Marcus Kracht, 1993. How completeness and correspondence theory got married. In de Rijke, editor, Diamonds and Defaults, pages 175–214. Kluwer.
• Henrik Sahlqvist, 1975. Correspondence and completeness in the first- and second-order semantics for modal logic. In Proceedings of the Third Scandinavian Logic Symposium. North-Holland, Amsterdam.
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2016-10-24 20:33:36
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|
https://proofwiki.org/wiki/Set_is_Subset_of_Finite_Infima_Set
|
# Set is Subset of Finite Infima Set
## Theorem
Let $\left({S, \preceq}\right)$ be an ordered set.
Let $X$ be a subset of $S$.
Then $X \subseteq \operatorname{fininfs}\left({X}\right)$
where $\operatorname{fininfs}\left({X}\right)$ denotes the finite infima set of $X$.
## Proof
Let $x \in X$.
$\left\{ {x}\right\}$ admits an infimum and $\inf \left\{ {x}\right\} = x$
By definitions of subset and singleton:
$\left\{ {x}\right\} \subseteq X$
$\left\{ {x}\right\}$ is a finite set.
Thus by definition of finite infima set:
$x \in \operatorname{fininfs}\left({X}\right)$
$\blacksquare$
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2020-08-14 19:33:44
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https://www.semanticscholar.org/paper/Mapping-gradient-driven-morphological-phase-at-the-Han-Eliseev/34ffd940779c6fb7f8ed06402c3f6b3179338ad4
|
# Mapping gradient-driven morphological phase transition at the conductive domain walls of strained multiferroic films
@article{Han2019MappingGM,
title={Mapping gradient-driven morphological phase transition at the conductive domain walls of strained multiferroic films},
author={M. J. Han and Eugene A. Eliseev and Anna N. Morozovska and Yu Hua Zhu and Yunlong Tang and Yujia Wang and X. W. Guo and Xiuliang Ma},
journal={Physical Review B},
year={2019}
}
• Published 13 March 2019
• Materials Science
• Physical Review B
The coupling between antiferrodistortion (AFD) and ferroelectric (FE) polarization, universal for all tilted perovskite multiferroics, is known to strongly correlate with domain wall functionalities in the materials. The intrinsic mechanisms of domain wall phenomena, especially AFD-FE coupling-induced phenomena at the domain walls, have continued to intrigue the scientific and technological communities because of the need to develop the future nano-scale electronic devices. Over the past years…
23 Citations
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## References
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Interplay between elasticity, ferroelectricity and magnetism at the domain walls of bismuth ferrite
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Multiferroic domain walls have recently been proposed as the active element in devices related to spintronics, data storage, and magnetic logic. Among multiferroics, BiFeO3 is by far the most studied
Labyrinthine domains in ferroelectric nanoparticles: a manifestation of gradient-driven morphological transition.
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In the framework of the Landau-Ginzburg-Devonshire (LGD) approach we studied finite size effects of the phase diagram and domain structure evolution in spherical nanoparticles of uniaxial
Atomic-scale evolution of modulated phases at the ferroelectric-antiferroelectric morphotropic phase boundary controlled by flexoelectric interaction.
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This study highlights the importance of local order-parameter mapping at the atomic scale and establishes a hitherto unobserved physical origin of spatially modulated phases existing in the vicinity of the MPB.
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The observation of room-temperature electronic conductivity at ferroelectric domain walls in the insulating multiferroic BiFeO(3) shows that the conductivity correlates with structurally driven changes in both the electrostatic potential and the local electronic structure, which shows a decrease in the bandgap at the domain wall.
Domain wall nanoelectronics
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Domains in ferroelectrics were considered to be well understood by the middle of the last century: They were generally rectilinear, and their walls were Ising-like. Their simplicity stood in stark
Local Enhancement of Polarization at PbTiO3/BiFeO3 Interfaces Mediated by Charge Transfer.
• Physics, Materials Science
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A charge transfer mechanism is proposed that leads to the remarkable polarization increment at the PbTiO3/BiFeO3 interface, which may facilitate the development of nanoscale ferroelectric devices by tailing the coupling of charge and lattice in oxide heteroepitaxy.
180° Ferroelectric Stripe Nanodomains in BiFeO3 Thin Films.
• Materials Science
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• 2015
The observation of 180° stripe nanodomains in (110)-oriented BiFeO3 thin films grown on orthorhombic GdScO3 (010)O substrates and their impact on exchange coupling to metallic ferromagnets is reported and found to be highly ordered.
Anisotropic conductivity of uncharged domain walls in BiFeO3
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Experimental observations suggest that nominally uncharged, as-grown domain walls in ferroelectrics can be conductive, yet comprehensive theoretical models to explain this behavior are lacking. Here,
Intrinsic structural instabilities of domain walls driven by gradient coupling: Meandering antiferrodistortive-ferroelectric domain walls inBiFeO3
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Using Landau-Ginzburg-Devonshire approach, we predict the intrinsic instability of the ferroelectric-ferroelastic domain walls in the multiferroic BiFeO3 emerging from the interplay between the
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We present a first-principles density-functional study of the structural, electronic, and magnetic properties of the ferroelectric domain walls in multiferroic ${\text{BiFeO}}_{3}$. We find that
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2022-05-28 16:22:04
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https://cs.stackexchange.com/questions/91937/nearest-codeword-in-a-translation-invariant-code-over-mathbbzd
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# Nearest codeword in a translation-invariant code over $\mathbb{Z}^d$
Let $c_1,...,c_n,c':\mathbb{Z^d}\rightarrow \{0,1\}$ all have finite support. Let $C$ be the linear, shift-invariant code generated by $c_1,..,c_n$.
It is possible to calculate the nearest codeword $c\in C$ to $c'$ (measured in Hamming distance)? Equivalently, is it decidable to tell given $k$ if $C\cap B(c',k)=\varnothing$? (the equivalence of the two versions is a nice exercise).
For $k=0$ this is just asking if $c'\in C$, essentially an ideal membership problem, decidable with Gröbner bases. $d=1$ is easy. Already for $d=2,k=1$ I'm stumped.
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2019-07-21 02:18:34
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https://plainmath.net/7932/find-the-roots-of-the-function-f-x-equal-2x-1-x-2-plus-2x-3-with-x-in-r
|
# Find the roots of the function f(x) = (2x − 1)*(x^2 + 2x − 3), with x in R
Find the roots of the function
$f\left(x\right)=\left(2x-1\right)\cdot \left({x}^{2}+2x-3\right)$, with $x\in R$
You can still ask an expert for help
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StrycharzT
First find the factors of $\left({x}^{2}+2x-3\right).$
Compare the $a{x}^{2}+bx+c$ and ${x}^{2}+2x-3$, implies that $a=1,b=2$, and $c=-3$.
The ac-method of factoring quadratics: To find factors of quadratic $a{x}^{2}+bx+c$, Find two numbers whose sum is b and product is $a\cdot c$.
Here $a\cdot c=1\cdot \left(-3\right)=-3$and $b=2$.
To find factors of quadratic ${x}^{2}+2x-3$, find two numbers whose sum is 2 and the product is -3.
Such numbers are 3 and -1.
The factors of $\left({x}^{2}+2x-3\right)$ are $\left(x+3\right)\left(x-1\right).$
The given function $f\left(x\right)=\left(2x-1\right)\cdot \left({x}^{2}+2x-3\right)$ becomes
$f\left(x\right)=\left(2x-1\right)·\left(x+3\right)·\left(x-1\right)$
Set $f\left(x\right)=0$, implies that
$\left(2x-1\right)\cdot \left(x+3\right)\cdot \left(x-1\right)=0$
By using zero product property,
$\left(2x-1\right)=0,\left(x+3\right)=0,\left(x-1\right)=0$
Implies that,
$2x=1,x=-3,x=1$
That is, the roots of the given function are,
$x=\frac{1}{2},x=-3,x=1.$
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2022-06-25 13:51:02
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https://gosahasecev.hermes-security.com/algebraic-approach-to-the-dynamics-of-a-linear-chain-with-an-impurity-book-32477zp.php
|
Last edited by Kazikree
Thursday, July 9, 2020 | History
2 edition of Algebraic approach to [the] dynamics of [a] linear chain with an impurity found in the catalog.
Algebraic approach to [the] dynamics of [a] linear chain with an impurity
Z. Inowe
# Algebraic approach to [the] dynamics of [a] linear chain with an impurity
## by Z. Inowe
Published in Trondheim .
Written in English
Subjects:
• Statistical thermodynamics.
• Edition Notes
Classifications The Physical Object Statement by Z. Inowe. Series Arkiv for det Fysiske seminar i Trondheim, 1968, no. 2, 4 LC Classifications QC1 .T73 1968, no. 2, etc. Pagination v. Open Library OL5725989M LC Control Number 70463559
The rapidly growing field of ab initio molecular dynamics is reviewed in the of a series of lectures. Several such molecular dynamics schemes are compared which arise from following various approximations to the fully Schrodinger equation for electrons and nuclei. Introduction to linear least square estimation: a geometric filter, Levinson filter, updating QR filter and the Kalman implementation structures: lattice, ladder and the systolic stic realization theory (modelling given the covariance). .
Cellular automata are a general approach to modeling the dynamics of spatially distributed systems. Expanding the notion of an iterative map of a single vari-able, the variables that are updated are distributed on a lattice in space. The influ-ence between variables is assumed to rely upon local interactions, and is homoge-neous. Logarithmic conformal field theory: a lattice approach. A M Gainutdinov 1, J L Jacobsen 2,3, N Read 4, H Saleur 1,5 and R Vasseur 1,2. Published 20 November • IOP Publishing Ltd Journal of Physics A: Mathematical and Theoretical, Vol Number
International Journal of Quantum Chemistry Vol Number 5, C. R. Sarma and N. Ravi Shankar and S. Rettrup A graphical scheme for representing many-electron spin-free configurations Raul Palmeiro and Luis Manuel Frutos and Obis Castaño Note on the theory of bifurcation of chemical reactions. Wolfram Cloud. Central infrastructure for Wolfram's cloud products & services. Wolfram Engine. Software engine implementing the Wolfram Language. Wolfram Universal Deployment System. Instant deployment across cloud, desktop, mobile, and more.
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### Algebraic approach to [the] dynamics of [a] linear chain with an impurity by Z. Inowe Download PDF EPUB FB2
The theory is illustrated by studying a model system of zero-dimensional (finite) Heisenberg spin chain with an impurity, which exhibits a nontrivial first-order quantum phase transition.
On the Dynamics of XY Spin Chains with Impurities. of a single magnetic impurity embedded in a linear quantum chain. We obtain a rigorous result for the expectation value of any spin in the Author: Giuseppe Genovese. In physics, the Bethe ansatz is an ansatz method for finding the exact wavefunctions of certain one-dimensional quantum many-body models.
It was invented by Hans Bethe in to find the exact eigenvalues and eigenvectors of the one-dimensional antiferromagnetic Heisenberg model then the method has been extended to other models in one dimension: the.
Abstract. Much of the recent research on distillation control has been treating the question of control system configuration. Dual-composition control by controlling temperature differences and sums in a column, various ways of reducing interaction by use of flow ratios as manipulators, and use of decoupling strategies are examples on discussed structures.
Note that we have not yet specified the boundary conditions for the system. For a normal mode of frequency, we have, for all /, Xi = -- 2(, and the differential equa tions (1) reduce to the linear algebraic set (2) FIG. The linear chain, with nearest-neighbour harmonic interactions. reasons for the preoccupation with simple : P.
Dean. Quench dynamics of disordered quantum impurity systems (DOE), S. Haas, H. Saleur, $, Quantum Quench Dynamics-Crossover Phenomena in Non-Equilibrium Correlated Quantum Systems (DOE), S. Haas, H. Saleur,$, Our approach is to implement lifting in the very formulation of the problem.
We, consequently, study mean field type control problems by formulating control problems on a Hilbert space of square integrable random variables. The novelty of our approach lies in the definition of this Hilbert space and its connection to the measure variable.
As already mentioned, for CFT represented by free fermions, but with nontrivial impurities, the partitioning approach for non-equilibrium steady states (usually referred to as the Keldysh formalism within this context) has been studied in a very large body of works, see e.g. the book and references therein; generically, in impurity models, the.
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web; books; video; audio; software; images; Toggle navigation.Radiation Physics of Metals and Its Applications. Book Title:Radiation Physics of Metals and Its Applications. Advances in power engineering based on nuclear power engineering and further advances in exploration of the cosmic space are determined to a large degree by the development of metallic materials for different functional applications, satisfying the requirement on services reliability.
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2020-12-04 22:41:06
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http://math.stackexchange.com/questions/244034/parametric-equation-problem
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# Parametric Equation Problem
The problem is, "to determine any differences between the curves of the parametric equations. Are the graphs the same? Are the orientations the same? Are the curves smooth? Explain."
(a) $x=t;\quad y=2t+1$
(b) $x=\cos\theta;\quad y=2\cos\theta +1$
(c) $x=e^{-t};\quad y=2e^{-t}+1$
(d) $x=e^t; \quad y=2e^t+1$
The only one I am having difficulty with is (b). The graph provided in the answer key is:
Why are the arrows pointing in both directions? Is there no orientation? Also, they describe the curve as not being smooth. Why is this?
EDIT:
I have another question; the criteria given in the problem above is the same for this problem.
The parametric equations are, (a) $x=\cos\theta$, $y=2\sin^2\theta$
(b) $x=\cos(-\theta)$, $y=2\sin^2(-\theta)$
where $0<\theta<\pi$.
With the information, $-1<\cos\theta<1 \implies -1<x<1$ and $0<\sin\theta<0\implies0<2\sin^2\theta<0\implies0<y<0$
In the answer key, however, they have $-1\le x\le1$ How did they get the "equal to" component in there?
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Hint for 1st part: $\cos\theta$ is a periodic function that cycles between $\pm 1$. A curve may fail to be smooth if its velocity vector is ever $0$--that is, if $x'$ and $y'$ are both $0$ at some point--as happens at the endpoints, here.
2nd part answer: As a hint for comparing the two parts, use the fact that sine is an odd function and cosine is an even function.
Assuming that the $0<\theta<\pi$ is correct, then you're correct that $-1<x<1$.
You are incorrect, though, in your claim that $0<\sin\theta<0$--for that would imply that $0$ is less than itself, which makes no sense. If you happen to know that a function is monotone (increasing or decreasing) on an entire interval--as is the case with $\cos\theta$ on the interval $0<\theta<\pi$--then you can simply check the values (or limiting behavior) at the endpoints of the interval to find the bounds of the function on that interval--as you did with $-1<\cos\theta<1$. Unfortunately, this doesn't work for all functions (as it can lead to problems like the aforementioned nonsense). On the interval $0<\theta<\pi$, we can say that $0<\sin\theta$, however, $\sin\theta$ achieves a maximum value of $1$ at $\theta=\frac\pi2$. Hence, $0<\sin^2\theta\le1$, and so $0<y\le2$.
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I tried searching for cyclic functions in google, but I couldn't find anything that you seem to be hinting at? Also, what do you mean by velocity vectors? – Mack Nov 25 '12 at 12:43
My apologies for misspeaking. I've corrected the first, and clarified the second. – Cameron Buie Nov 25 '12 at 13:00
No, it's quite all right. I do appreciate your help. One more thing, do you know of any online article(s) I could on this topic of smoothness of a curve? I was never taught that a curve wasn't smooth when it had a zero first derivative at a particular point. – Mack Nov 25 '12 at 13:10
You can check out this link. It's entirely possible that you're using a different definition of "smooth" in your class, though. If so, it's probably a good idea to specify the definition in your post, so we can answer appropriately. – Cameron Buie Nov 25 '12 at 13:38
My post has been edited, containing a similar problem I am working on, and I was wondering if you could take a look. – Mack Nov 25 '12 at 14:48
Though,each of the parametric equation reduce to $y=2x+1,$ the ranges of the values of $x$ for the real values of $t,\theta$ will differ.
In $(a),x$ cam assume any real values.
But in $(b),-1\le x\le 1$
In $(c),(d),x>0$ for the real values of $t$.
Using this, each curve has orientation zero.
-
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2014-11-25 22:04:42
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https://coding-gym.org/challenges/absent-students/
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# The Absent Students
See the original problem on HackerRank.
A professor calls out student IDs of students one by one while marking attendance. He notices that the number of students recorded in the attendance sheet is far more than the number of students who are actually present in the classes.
Hence, he decides to use a robot which can record the students’ voices and keep track of which students have responded to attendance calls.
At the end of each session, the robot outputs the student IDs of the students who have responded to attendance calls. With this information, the professor needs your help to find out which students were absent.
Complete the function findTheAbsentStudents which takes in an integer array $$a$$ denoting the student IDs recorded by the robot and returns the list of student IDs of the students which were absent in increasing order.
### Input Format
The first line of input contains a single integer $$n$$ denoting the number of students.
The second line contains $$n$$ space-separated integers $$a_1,a_2,...,a_n$$ denoting the student IDs recorded by the robot. The students have IDs from $$1$$ to $$n$$, inclusive.
### Constraints
• $$1 \leq n \leq 100$$
• $$1 \leq a_i \leq n$$
• There is at least one absent student.
### Output Format
Print a single line containing the student IDs of the students which were absent, space-separated and in increasing order.
## Solutions
Since the input of this problem is quite little, an $$O(N^2)$$ solution works. Basically, we could loop from 1 to $$N$$ and check if each element appears in the input. If not, we print that number.
We are at Coding Gym and we could do much better than this.
At Coding Gym, we tag this kind of challenges as “Manifold”, meaning that many different solutions exist.
First of all, it’s worth noticing that this exercise is a specialization of a much more general problem: given two list of elements, find which elements from the first list are missing in the second. Usually, to solve such a problem hash tables or set difference are enough.
A very first solution to our challenge consists in creating a set from $$1$$ to $$N$$ and simply calculating the difference with the input, turned into a set too:
1 2 3 4 5 max_ids = int(input()) all_ids = {x for x in range(1, max_ids+1)} students = {int(x) for x in input().split()} absents = all_ids - students print(' '.join((str(x) for x in sorted(absents))))
Some costs:
• $$O(N)$$ extra space for the support range
• turning the input sequence into a sorted set is $$O(N \cdot LogN)$$
• set difference is linear
• absent students set must be sorted for printing
Hashing is discussed bit at the end.
Anyway, for our problem such extra space is not really a problem and we could even generate an incremental range on the fly.
What makes our problem even more interesting is that we can exploit its structure and constraints.
## Sort-based solutions
We need to check numbers from $$1$$ to $$N$$. This means we can sort the input and just check linearly:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 int n; cin >> n; vector v(n); copy_n(istream_iterator(cin), n, begin(v)); sort(begin(v), end(v)); v.erase(unique(begin(v), end(v)), end(v)); // remove duplicates auto expected = 1; for (auto i=0; i
We can decide to remove duplicates or not depending on the size of the input: since we know that elements spans from $$1$$ to $$100$$, it’s not hard to imagine that when $$N$$ is bigger that 100, duplicates are certain.
A similar solution consists in using a set (or any other sorted data structure) instead of array + sort.
Sometimes we are allowed to modify the input, this means we could not remove duplicate elements. In this case it’s worth mentioning this variant based on lower bound:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 int n; cin >> n; vector v(n); copy_n(istream_iterator(cin), n, begin(v)); sort(begin(v), end(v)); auto last = begin(v); for (auto i=1; i<=n; ++i) { auto lb = lower_bound(last, end(v), i); if (lb != end(v) && *lb == i) { last = lb; } else { cout << i << " "; } }
All the solutions above are affected by sorting, meaning they are order of $$O(N \cdot LogN)$$.
## Extra-space-based solutions
Is it possible to solve this problem linearly?
Since the solutions above are dominated by the sort cost, we have to think of another way to obtain the same information that sort gives without actually sorting.
We could use some extra space to mark each element we read. Actually, if we don’t really need the input, we won’t have any extra space at all!
Since the input is little, we could have a constant extra space:
1 2 3 4 5 6 7 8 9 10 int n; cin >> n; array freq{}; int val; while (cin >> val) freq[val]++; for (auto i=1; i
In general, we could use a hash table:
1 2 3 4 5 6 7 8 9 10 int n; cin >> n; unordered_map freq{}; int val; while (cin >> val) freq[val]++; for (auto i=1; i
This last snippet could adapted to solve the more general problem of two arbitrary ranges.
### Solution (alepez)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 #include #include #include #include #include using namespace std; int main() { int n; cin >> n; vector a; while (cin.good()) { int i; cin >> i; a.push_back(i); } sort(a.begin(), a.end()); a.erase(unique(a.begin(), a.end()), a.end()); int s = 0; auto it = a.begin(); while (++s <= n) { if (it != a.end() && s == *it) { /* found */ ++it; } else { /* not found */ cout << s << " "; } } return 0; }
### Javscript Solution (alepez)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 function processData(input) { const [ n, astr ] = input.split('\n'); const a = [... new Set(astr.split(' ').map(s => Number(s)).sort((a,b) => a - b))]; let s = 0; let index = 0; const notFound = []; while (++s <= n) { if (index < a.length && s === a[index]) { /* found */ ++index; } else { /* not found */ notFound.push(s); } } return notFound.join(' '); }
We've worked on this challenge in these gyms: modena padua milan turin
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2019-09-20 00:59:39
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https://docs.sysdig.com/en/-legacy--commands-audit.html
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[Legacy] Commands Audit
The Commands Audit module provides Sysdig Secure users with a searchable and sortable audit trail of user commands executed within the infrastructure.
Note
While policy events are an inherently suspicious activity that warrants investigation, commands are not themselves considered suspicious.
The Sysdig Agent examines all execve events. Information about commands that meet the following criteria is saved by the Sysdig backend, and made available for review as a command entry in the Commands Audit module table:
• A program was launched by a shell associated with a terminal (i.e. is related to a user-entered command).
• The parent process was launched in a running container (i.e. the result of a docker exec <container> command).
Warning
If an excessive volume of commands occurs in a given second, some commands may be excluded from the information sent from the agent to the Sysdig backend.
The table below outlines the information displayed in the Command Audits module:
Data
Description
Time
The date and time the command was executed.
Shell
The terminal shell the command was executed in.
Command Line
The full command executed, including flags/variables.
Scope
The affected scope within the infrastructure.
Review a Command
Individual commands can be reviewed by selecting the line item in the Commands Audit module table. This opens the Command Details window:
The table below outlines the information displayed in the Command Details window:
Name
Description
When
The date and time the command was executed.
Command
The command executed.
Full Command Line
The complete command, including all variables/options.
Working Directory
The directory the command was executed in.
Scope
The entities within the infrastructure impacted by the command.
Host
The hostname and MAC address of the host the command was executed on.
Container
The container ID, container name, and image that the command was executed on.
Detailed user/host information:
• The Process ID (PID) of the command.
• The Parent Process ID (PPID) of the command.
• The user ID of the user that executed the command.
• The Shell ID.
• The distance from the root of the process hierarchy.
Filtering the Commands Table
The Commands Audit module's table can be filtered to display only the most relevant commands for a particular issue, or to provide greater visibility of a more targeted scope within the infrastructure. There are three ways to filter the table, which can be used in tandem to refine the information presented.
Groupings
Groupings are hierarchical organizations of labels, allowing users to organize their infrastructure views in a logical hierarchy. Users can switch between pre-configured groupings via the Browse By menu, or configure custom groupings, and then dive deeper into the infrastructure. For more information about groupings, refer to the Configure Groupings in Sysdig Secure documentation
Note
Sysdig Secure does not currently provide the functionality to configure a custom time window.
Search Filters
Search filters can be applied by either using the search bar directly or by adding pre-configured search strings via the Command Details panel. The search bar example below displays only table items that include apt-get:
To use a pre-configured search string:
1. From the Commands Audit module, select a command from the table to open the Command Details window.
2. Add a filter by click the Add link beside one of the available options:
The example below shows the table filtered by the working directory:
Pre-configured filters exist for the following information:
• Command
• Working Directory
• Process ID
• Parent Process ID
• User ID
• Shell ID
• Shell Distance
Note
Search filters can be deleted by either deleting the text in the search bar or clicking the Remove link beside the filter in the Command Details window.
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2020-09-25 23:16:25
|
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http://cms.math.ca/10.4153/CJM-1998-045-4
|
location: Publications → journals → CJM
Abstract view
Lusternik-Schnirelmann category and algebraic $R$-local homotopy theory
In this paper, we define the notion of $R_{\ast}$-$\LS$ category associated to an increasing system of subrings of $\Q$ and we relate it to the usual $\LS$-category. We also relate it to the invariant introduced by F\'elix and Lemaire in tame homotopy theory, in which case we give a description in terms of Lie algebras and of cocommutative coalgebras, extending results of Lemaire-Sigrist and F\'elix-Halperin.
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2015-04-26 17:13:34
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http://tex.stackexchange.com/questions/14976/how-to-get-sequential-references-in-my-paper/14979
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# How to get sequential references in my paper?
I'm using TeXnicCenter to write my all document and generate my bib file by using JabRef. However I noticed that my references are out of order. It seems the addition order to JabRef file forces the numbering in my file. Is there a way to see my references sequentially in my paper?
For example,
In my bib file:
1. Berkay et al. Using References efficiently.
2. Alan et al. Asking better questions in TeX exchange.
In my tex:
Berkay et al [2] proposed a solution for references and recently Alan et al. [1] criticized him.
My question refers having them [1] and [2], sequentially, in order.
-
It's quite hard to tell from your question what the problem is, or what you're doing. Are you using `natbib`? What do you mean by 'out of order'? What order are the references in, and what order do you want them in? What kind of citation system are you using (author/year, numeric?). – Alan Munn Apr 5 '11 at 3:02
@Alan Munn sorry for confusing points, edited.Thanks. – berkay Apr 5 '11 at 3:14
possible duplicate of Sort thebibliography by citation order – Charles Stewart May 4 '11 at 14:35
If I understand the question correctly, that you want the bibliography arranged in the order that each item is first cited, then you need to write `\bibliographystyle{unsrt}` or if you are using `natbib` then `\bibliographystyle{unsrtnat}`.
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2016-05-31 00:08:15
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|
http://tex.stackexchange.com/questions/9046/referencing-a-nested-list-item-by-only-its-most-immediate-bullet
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# Referencing a nested list item by only its most immediate bullet
I'd like to be able to reference a nested enumerated list item only by its inner-most identifying character.
\begin{enumerate}[(1)]
\item
\begin{enumerate}[(a)]
\item \label{mylabel} Referenced point.
\end{enumerate}
\end{enumerate}
...
\ref{mylabel}
The \ref above gives me something like 1a, but I want it to give me a only.
-
In LaTeX, internal macro \p@enumN\theenumN defines the output of a \ref command. (ref. source2e) The default definitions in standard document classes are (ref. classes):
\renewcommand\theenumi{\@arabic\c@enumi}
\renewcommand\theenumii{\@alph\c@enumii}
\renewcommand\theenumiii{\@roman\c@enumiii}
\renewcommand\theenumiv{\@Alph\c@enumiv}
\renewcommand\p@enumii{\theenumi}
\renewcommand\p@enumiii{\theenumi(\theenumii)}
\renewcommand\p@enumiv{\p@enumiii\theenumiii}
You can redefine \p@enumii to get what you want:
\makeatletter % for internal macros with @
\renewcommand\p@enumii{}
\makeatother
It seems you are using enumerate package to change the label. However, enumerate doesn't handle the cross references well. I suggest a more modern package enumitem to replace enumerate, which can also ease the problem using key-value syntax. For example:
% \usepackage{enumitem} % in preamble
\begin{enumerate}[label=(\arabic*)]
\item
\begin{enumerate}[label=(\alph*),ref=\alph*]
\item \label{mylabel} Referenced point.
\end{enumerate}
\end{enumerate}
-
Both suggestions work for me. Thanks! – Isaac Sutherland Jan 16 '11 at 2:59
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2014-04-18 13:41:59
|
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|
https://bitbucket.org/gabriele/pyquante-site/src/166f0f8ea168/source/index.rst
|
# PyQuante: Python Quantum Chemistry
## Overview
PyQuante (Sourceforge Project Page) is an open-source suite of programs for developing quantum chemistry methods. The program is written in the Python programming language, but has many "rate-determining" modules also written in C for speed. The resulting code, though not as fast as Jaguar, NWChem, Gaussian, or MPQC, is much easier to understand and modify. The goal of this software is not necessarily to provide a working quantum chemistry program (although it will hopefully do that), but rather to provide a well-engineered set of tools so that scientists can construct their own quantum chemistry programs without going through the tedium of having to write every low-level routine.
### Current features
• Hartree-Fock: Restriced closed-shell HF and unrestricted open-shell HF;
• DFT: LDA (SVWN, Xalpha) and GGA (BLYP) functionals;
• Optimized-effective potential DFT;
• Two electron integrals computed using Huzinaga, Rys, or Head-Gordon/Pople techniques; C and Python interfaces to all of these programs;
• MINDO/3 semiempirical energies and forces;
• CI-Singles excited states;
• DIIS convergence acceleration;
• Second-order Moller-Plesset (MP2) perturbation theory.
### Getting Started
See the cookbook for short snippets to get started, and also see the tests subdirectory of the code distribution. Subscription to the pyquante-users mailing list is highly recommended for further nsupport. Additionally, people interested in day-to-day development issues in PyQuante are urged to subscribe to the pyquante-devel mailing list.
The software is released under the modified BSD license, which means that everyone is free to download, use, and modify the code without charge.
The program is available in tarball form from the PyQuante Sourceforge Project Page. The SVN archive for the program is also at Sourceforge, and is recommended for anyone wanting to stay current with the codebase; information on how to access the SVN archive is available here.
### Prerequisites
You will need to have a recent (2.3 or later) version of Python installed on your computer; this can be installed by following instructions on the Python Website, and binary packages exist for most platforms. Additionally, you need the multidimensional arrays and linear algebra libraries provided by either Numeric or numpy; both of these can be downloaded from the Numpy Website.
Given the choice between Numeric and Numpy, please use Numpy. The library is much newer, and future developments will center on this library. Although we will make every effort to continue supporting Numeric, Numpy is what we will use as the default, and should be much more stable with PyQuante.
Note: If you're installing on a Macintosh, I recommend the Framework binaries of Python and Numpy from the Pythonmac Packages Directory.
On Ubuntu and other Linux distros, several additional packages may be required, including python-dev, python-numpy, and possibly python-matplotlib.
### Building the Code
Much of the code is written in Python, and thus is platform independent. The rest of the code now uses the python distutils procedures for building the C modules:
% (sudo) python setup.py install
and the code should build and install properly. I've tested this on Linux, Windows/Cygwin, and Macintosh OS X. Installing the module like tsetxkbmap -option ctrl:nocaps # Make Caps Lock a Control key his will insure that the modules are installed where Python can find them.
However, the above assumes that you have write priviledges in the Python site-packages directory, possibly via the _sudo_ command. If you do not have access to these directories, create an install directory where you do have access and pass this directory to the install process:
% mkdir ~/pyquante_lib
% python setup.py install --install-lib=~/pyquante_lib
% export PYTHONPATH=~/pyquante_lib:\$PYTHONPATH
Email me ([email protected]) if you need additional help.
## Using the Code
### Cookbook
#### Specifying a molecule
You can specify a molecule using the following code:
>>> from PyQuante.Molecule import Molecule
>>> h2 = Molecule('h2',[(1,(0,0,0)),(1,(1.4,0,0))])
#### Simple HF calculation
Using the above definition, you can run a simple HF calculation via:
>>> from PyQuante.hartree_fock import rhf
>>> en,orbe,orbs = rhf(h2)
>>> print "HF Energy = ",en
We're also working on a more object-oriented interface (called PyQuante 2) that will hopefully decrease the amount of duplicated code in the project. You can run the same calculation as above using:
>>> from PyQuante import SCF
>>> solver = SCF(h2,method="HF")
>>> solver.iterate()
>>> print "HF Result = ",solver.energy
With the new solvers, you can run with an alternate basis set (say, STO-3G), via:
>>> solver = SCF(h2,method="HF",basis="sto-3g")
>>> solver.iterate()
>>> print "HF Result = ",solver.energy
At this geometry (R=1.4 bohr) this should produce an energy of -1.1313 hartrees. Note that you may also import Molecule and SCF directly from the PyQuante namespace now.
#### Simple DFT calculation
We can run a DFT calculation on the same molecule by running the commands:
>>> from PyQuante.dft import dft
>>> en,orbe,orbs = dft(h2)
This will produce an energy of -1.1353 hartrees. Again, the 6-31G** basis set is used by default. In DFT calculations, the functional defaults to SVWN (LDA). To use a different functional, you can type:
>>> en,orbe,orbs = dft(h2,functional='BLYP')
which will produce an energy of -1.1665 hartrees.
With the new solvers this calculation could be run via:
>>> from PyQuante import SCF
>>> lda = SCF(h2,method="DFT")
>>> lda.iterate()
>>> blyp = SCF(h2,method="DFT",functional="BLYP")
>>> blyp.iterate()
>>> print "DFT Results: LDA = %f BLYP = %f" % (lda.energy,blyp.energy)
### Users Guide
Here we provide a bit more detail about the PyQuante functions.
#### Molecules
PyQuante programs use the Molecule object to contain the information about the molecule - the atoms, the charge, and the multiplicity. The syntax for Molecule is:
>>> Molecule(name,atomlist,**opts)
The atomlist is a list of atomic numbers and a tuple with the x,y,z coordinates. Here's an example for constructing a molecule object for water:
>>> h2o=Molecule('h2o',[(8,(0,0,0)),(1,(1.0,0,0)),(1,(0,1.0,0))],units = 'Angstrom')
(of course the bond-angle is 90 degrees here, and is thus completely wrong, but this is only an example). Here's an example for the hydroxide ion that shows the use of the charge field:
>>> oh = Molecule('OH-',[(8,(0,0,0)),(1,(0.96,0,0))], units = 'Angstrom', charge=-1)
Here's an example for the NO molecule that shows the use of the multiplicity field:
>>> no = Molecule('NO', [(7,(0,0,0)),(8,(2.12955,0,0))],multiplicity=2)
As of version 1.5.1, you may construct molecules using the atomic symbol instead of the atomic number, e.g.:
>>> h2o=Molecule('h2o',[('O',(0,0,0)), ('H',(1.0,0,0)),('H',(0,1.0,0))],units = 'Angstrom')
Currently, the semiempirical code uses an extended verion of the Molecule object that adds a variety of additional features. Upcoming releases will hopefully unify the use of the Molecule between the HF, DFT, and semiempirical codes.
As of version 1.6, you can directly import Molecule from the PyQuante module:
>>> from PyQuante import Molecule
#### Basis Sets
Basis functions are constructed using the CGBF (contracted Gaussian basis function) object, which, in turn, uses the PGBF (primitive Gaussian basis function) object. Basis sets are simply lists of CGBF's. In the Ints module there is a convenience function getbasis that constructs basis sets for different molecules. The syntax for the getbasis function is:
>>> bfs = getbasis(molecule,basis_data=None)
The basis data can be input from a number of data files in the PyQuante suite. Here are some of the more commonly used basis sets:
• basis_631ss The Pople 6-31G** basis set
• basis_sto3g The Pople STO-3G basis set
• basis_321 The Pople 3-21G basis set
• basis_ccpvtz The Dunning cc-pVTZ basis set
• basis_ccpvtzmf The Dunning cc-pVTZ(-f) basis set (cc-pVTZ without f-functions)
For, example, to construct a basis set for the h2o object for water created above, we would call:
>>> from basis_631ss import basis_data
>>> bfs = getbasis(h2o,basis_data)
If the basis_data argument is omitted, the program will default to 6-31G**. As of version 1.6, you may now specify a string for the basis_data argument, e.g. "6-31G**" so you may do things like:
>>> bfs = getbasis(h2o,'6-31G**')
>>> bfs2 = getbasis(h2o,'sto-3g')
and so on. Use PyQuante.Basis.Tools.basis_map.keys() for a list of the supported basis strings.
#### Output
If you want to check the output of PyQuante and to have a feedback of what's happening, you can use the configure_output routine before launching the calculation:
>>> from PyQuante import configure_output
>>> configure_output()
This will display to the standar output the log of PyQuante. You can also specify other ways to handle the output:
>>> configure_output("calc.log") # save also in a log file and display on stdout
>>> configure_output(stream=sys.stderr) # Redirect the output on a generic stream
>>> configure_output(filename="h2.log", stream=None) # Suppress stream output
Internally, the output is handled using the logging module (available in the standard library), you can access the logger used by PyQuante in this way:
>>> import logging
>>> logger = logging.getLogger("pyquante")
Further information about using Loggers: http://docs.python.org/library/logging.html
#### Integrals
##### One-electron integrals
The one-electron integrals consist of the overlap matrix S, the kinetic energy matrix T, and the nuclear attraction matrix V. The latter two are often combined into the one-electron Hamiltonian h.
There are a number of helper functions in the Ints module:
• getT: Form the kinetic energy matrix T
• getS: Form the overlap matrix S
• getV: Form the nuclear attraction matrix V
• get1ints: Form and return S,h
• getints: Form and return S,h,Ints, where Ints are the two-electron integrals (see below).
These functions actually call instance functions of the CGBF objects, which can themselves be used individually. Some of the instance functions in the CGBF module use functions in the pyints and cints modules.
##### Two-electron integrals
The two-electron integrals consist of the electron-electron Coulomb repulsion interactions. The easiest way to construct these is to use the functions in the Ints module
• get2ints: Form and return Ints, where Ints are the two-electron integrals (see below).
• getints: Form and return S,h,Ints, where Ints are the two-electron integrals.
The Ints object (not to be confused with the Ints module, which is just a collection of helper functions) consists of a list of the two-electron integrals.
There are actually three different methods to computing the two-electron integrals, and the helper functions in the Ints module default to one of these functions.
• Huzinaga's original method for computing integrals over Gaussians.
• Head-Gordon and Pople's recurrance relations.
There are python versions of these methods implemented in the modules pyints, rys, and hgp, respectively. For speed, there are also C-versions of these modules in cints, crys, and chgp. The program defaults to the Coulomb repulsion routines in crys, since these are the fastest (although recent improvements to chgp make it not much slower).
The coulomb_repulsion function is the same in all six modules:
>>> integral = coulomb_repulsion((xa,ya,za),norma,(la,ma,na),alphaa,
(xb,yb,zb),normb,(lb,mb,nb),alphab,
(xc,yc,zc),normc,(lc,mc,nc),alphac,
This routine computes the Coulomb repulsion integral between four basis functions. The terms xi, yi, zi are the origins of the different basis functions. The terms normi are the normalization constants for the basis function. The terms li, mi, ni are the exponents of the Cartesian powers for the basis function. And the terms alphai are the Gaussian exponents.
#### Hartree-Fock Calculations
This section is under construction. In the meantime, see the PyQuante Cookbook recipe Simple HF calculation for an example of a HF calculation using PyQuante.
#### Density Functional Theory Calculations
This section is under construction. In the meantime, see the PyQuante Cookbook recipe Simple DFT calculation for an example of a DFT calculation using PyQuante.
#### Semiempirical Calculations
This section is under construction.
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2015-07-08 01:33:35
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https://codeforces.com/problemset/problem/895/E
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E. Eyes Closed
time limit per test
2.5 seconds
memory limit per test
256 megabytes
input
standard input
output
standard output
Vasya and Petya were tired of studying so they decided to play a game. Before the game begins Vasya looks at array a consisting of n integers. As soon as he remembers all elements of a the game begins. Vasya closes his eyes and Petya does q actions of one of two types:
1) Petya says 4 integers l1, r1, l2, r2 — boundaries of two non-intersecting segments. After that he swaps one random element from the [l1, r1] segment with another random element from the [l2, r2] segment.
2) Petya asks Vasya the sum of the elements of a in the [l, r] segment.
Vasya is a mathematician so he answers Petya the mathematical expectation of the sum of the elements in the segment.
Your task is to write a program which will answer the second type questions as Vasya would do it. In other words your program should print the mathematical expectation of the sum of the elements of a in the [l, r] segment for every second type query.
Input
The first line contains two integers n, q (2 ≤ n ≤ 105, 1 ≤ q ≤ 105) — the number of elements in the array and the number of queries you need to handle.
The second line contains n integers ai (1 ≤ ai ≤ 109) — elements of the array.
The next q lines contain Petya's actions of type 1 or 2.
If it is a type 1 action then the line contains 5 integers 1, l1, r1, l2, r2 (1 ≤ l1 ≤ r1 ≤ n, 1 ≤ l2 ≤ r2 ≤ n).
If it is a type 2 query then the line contains 3 integers 2, l, r (1 ≤ l ≤ r ≤ n).
It is guaranteed that there is at least one type 2 query and segments [l1, r1], [l2, r2] don't have common elements.
Output
For each type 2 query print one real number — the mathematical expectation of the sum of elements in the segment.
Your answer will be considered correct if its absolute or relative error doesn't exceed 10 - 4 — formally, the answer is correct if where x is jury's answer and y is yours.
Examples
Input
4 41 1 2 21 2 2 3 32 1 21 1 2 3 42 1 2
Output
3.00000003.0000000
Input
10 51 1 1 1 1 2 2 2 2 21 1 5 6 102 1 51 1 5 6 101 1 5 6 102 6 10
Output
6.00000008.0400000
Input
10 101 2 3 4 5 6 7 8 9 101 1 5 6 101 1 5 6 102 1 51 1 3 6 92 1 31 5 7 8 101 1 1 10 102 1 52 7 102 1 10
Output
23.000000014.000000028.013333321.573333355.0000000
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2021-01-21 01:29:43
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https://math.stackexchange.com/questions/1312415/about-mathbbr-as-a-vector-space-over-mathbbq
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# About $\mathbb{R}$ as a vector space over $\mathbb{Q}$
I want to understand better the structure of the vector space $\mathbb{R}$ over $\mathbb{Q}$. I know that it is an infinite dimensional vector space with a non countable Hamel basis, and it is cited in many works just for this properties. But, searching online, I don't find any satisfactory treatment of the properties of such space. E.g. :
What is its dual space? and the dual of the dual?
There is some way to characterize his subspaces? there is some equivalence relation between them (as for the dimension in countable vector spaces) and, in general, we can define a dimension of the subspaces?
Is it possible to define an inner product on this space?
So: I don't want here an answer to all this question, but I ask if there is some accessible resurse where I can find a specific and exhaustive study of this space that seem to me very interesting.
• The usual inner product is also one when the space is regarded over the rationals. – Tobias Kildetoft Jun 4 '15 at 19:11
• Just a bit of a grammar tip, in English if you are referring to something that's not alive (like a vector subspace) the possessive is "its" instead of "his" (i.e. "What is his dual space?" $\rightarrow$ "What is its dual space?"). It's clear what you mean, I just thought you might like to know. – Matt Samuel Jun 4 '15 at 19:16
• @Matt :Thank a lot ! My English is very primitive :) – Emilio Novati Jun 4 '15 at 19:22
The reason that you can't find any references on this is that there's nothing particularly special about $\mathbb{R}$ as a vector space over $\mathbb{Q}$ -- it's isomorphic to any other vector space over $\mathbb{Q}$ whose basis has the same cardinality.
In particular, define the dimension of a vector space to be the cardinality of any basis for the vector space. It is not hard to see that $\dim(V) = |V|$ for any infinite-dimensional vector space over $\mathbb{Q}$, and thus $\mathbb{R}$ is a vector space of dimension $|\mathbb{R}|$. Two vectors spaces over $\mathbb{Q}$ are isomorphic if and only if they have the same dimension.
If $B$ is a basis for $\mathbb{R}$ over $\mathbb{Q}$, then linear functionals from $\mathbb{R}$ to $\mathbb{Q}$ are in one-to-one correspondence with functions $B\to \mathbb{Q}$. In particular, the dual space is isomorphic to $\mathbb{Q}^\mathbb{R}$, the vector space of all functions $\mathbb{R}\to\mathbb{Q}$, whose cardinality is the same as that of the power set of $\mathbb{R}$.
In general, if $V$ is any infinite-dimensional vector space over $\mathbb{Q}$, then $|V^*| = |\mathcal{P}(V)|$. By Cantor's theorem, it follows that $$|\mathbb{R}| \;<\; |\mathbb{R}^*| \;<\; |\mathbb{R}^{**}| \;<\; |\mathbb{R}^{***}| \;<\; \cdots.$$
As for subspaces, every subspaces of $\mathbb{R}$ has a dimension as defined above, which must be a cardinal less than or equal to $|\mathbb{R}|$. Thus there are finite-dimensional subspaces of every possible dimension, as well as countable-dimensional subspaces and subspaces isomorphic to $\mathbb{R}$. If you believe the continuum hypothesis then these are the only possibilities, but if you don't believe the continuum hypothesis then there are subspaces of other intermediate cardinalities.
Every subspace $S$ also has a codimension, which is the dimension of $\mathbb{R}/S$, or equivalently the dimension of any complementary subspace to $S$. If $\dim(S) < |\mathbb{R}|$, then $\mathrm{codim}(S) = |\mathbb{R}|$, but if $\dim(S) = |\mathbb{R}|$, then $\mathrm{codim}(S)$ may be any cardinal less than or equal to $|\mathbb{R}|$. If $S$ and $S'$ are subspaces of $\mathbb{R}$, then there exists a $\mathbb{Q}$-linear bijection $\mathbb{R}\to\mathbb{R}$ taking $S$ to $S'$ if and only if $S$ and $S'$ have the same dimension and the same codimension.
It is possible to put a $\mathbb{Q}$-valued inner product on $\mathbb{R}$, but it isn't very meaningful. Basically, for any basis $B$ of $\mathbb{R}$, there exists a $\mathbb{Q}$-valued inner product on $\mathbb{R}$ under which that basis is orthonormal. This is basically defined by taking the "dot product" of the coefficient vectors of two real numbers with respect to this basis. More generally, it is possible to put a $\mathbb{Q}$-valued inner product on any vector space over $\mathbb{Q}$ by choosing a basis to be orthonormal.
• thank you! Do you know some reference useful to better understand such kind of vector spaces over $\mathbb{Q}$? – Emilio Novati Jun 4 '15 at 20:08
• @EmilioNovati There's really not much to know. Most advanced linear algebra or advanced abstract algebra books prove most of the basic theory of vector spaces without assuming finite-dimensionality -- just look for a book that uses Zorn's lemma to prove that every vector space has a basis. – Jim Belk Jun 4 '15 at 20:17
• I've same problem to figure how we can define a dot product for a non countable basis. How can I find the coefficents of a real number with repect to basis if I can not know all the elements of the basis? – Emilio Novati Jun 4 '15 at 20:18
• @EmilioNovati You can't. This is all abstract -- you can't actually find a basis for $\mathbb{R}$ over $\mathbb{Q}$ without the axiom of choice, which means that practically speaking you can't make one. However, it is true that any set of $\mathbb{Q}$-linearly independent real numbers extends to a basis. For example, if you want a basis that contains $\{1,\pi,\sqrt{2}\}$, you can have it, in which case $1$, $\pi$, and $\sqrt{2}$ will be orthonormal. – Jim Belk Jun 4 '15 at 20:23
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2019-08-21 07:03:18
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|
https://ebin.pub/random-generators-and-normal-numbers.html
|
• Like this paper and download? You can publish your own PDF file online for free in a few minutes!
##### Citation preview
Random Generators and Normal Numbers David H. Bailey1 and Ri hard E. Crandall2 30 O tober 2001
Abstra t
Pursuant to the authors' previous haoti -dynami al model for random digits of fundamental onstants [3℄, we investigate a omplementary, statisti al pi ture in whi h pseudorandom number generators (PRNGs) are entral. Some rigorous results su h as the following are a hieved: Whereas the fundamental onstant log 2 = 2 + 1=(n2 ) is not yet known to be 2-normal (i.e. normal to base 2), we are able to establish b-normality (and trans enden y) for onstants of the form 1=(nb ) but with the index n onstrained to run over ertain subsets of Z + . In this way we demonstrate, for example, that the onstant 2 3 = =3 32 33 1=(n2 ) is 2-normal. The onstants share with ; log 2 and others the property that isolated digits an be dire tly al ulated, but for the new lass su h
omputation is extraordinarily rapid. For example, we nd that the googol-th (i.e. 10100 th) binary bit of 2 3 is 0. We also present a olle tion of other results | su h as density results and irrationality proofs based on PRNG ideas | for various spe ial numbers.
P
P
;
P
n
n
n
Z
n
n
;
;
;:::
;
Lawren e Berkeley National Laboratory, Berkeley, CA 94720, USA, dhbaileylbl.gov. Bailey's work is supported by the Dire tor, OÆ e of Computational and Te hnology Resear h, Division of Mathemati al, Information, and Computational S ien es of the U.S. Department of Energy, under ontra t number DE-AC03-76SF00098. 2 Center for Advan ed Computation, Reed College, Portland, OR 97202 USA, randallreed.edu. 1
1
1. Introdu tion
We all a real number b-normal if, qualitatively speaking, its base-b digits are \truly random." For example, in the de imal expansion of a number that is 10-normal, the digit 7 must appear 1=10 of the time, the string 783 must appear 1=1000 of the time, and so on. It is remarkable that in spite of the elegan e of the lassi al notion of normality, and the sobering fa t that almost all real numbers are absolutely normal (meaning bnormal for every bp= 2; 3; : : :), proofs of normality for fundamental onstants su h as log 2; ; (3) and 2 remain elusive. In [3℄ we proposed a general \Hypothesis A" that
onne ts normality theory with a ertain aspe t of haoti dynami s. In a subsequent work, J. Lagarias [28℄ provided interesting viewpoints and analyses on the dynami al
on epts. In the present paper we adopt a kind of omplementary viewpoint, fo using upon pseudorandom number generators (PRNGs), with relevant analyses of these PRNGs arried out via exponential-sum and other number-theoreti al te hniques. One example of su
ess along this pathway is as follows: Whereas the possible b-normality of the fundamental
onstant 1 log 2 = 2 + n2
X
n
n
Z
remains to this day unresolved (for any b), we prove that for ertain subsets S bases b, the sum 1
X
Z + and
2 nb
n
n
S
is indeed b-normal (and trans endental). An attra tive spe ial ase is a number we denote 2 3, obtained simply by restri ting the indi es in the log 2 series de nition to run over powers of 3: ;
X
;
X
1 1 1 = 3k =1 3 2 =3k 1 n2 = 0:0418836808315029850712528986245716824260967584654857 : : : 10 = 0:0AB8E38F684BDA12F684BF35BA781948B0FCD6E9E06522C3F35B : : :16 ;
2 3 =
n
n
k
k
>
whi h number we now know to be 2-normal (and thus 16-normal as well; see Theorem 2.2(6)). It is of interest that until now, expli it b-normal numbers have generally been what one might all \arti ial," as in the ase of the 2-normal, binary Champernowne
onstant:
C2 = 0:(1)(10)(11)(100)(101)(110)(111) 2 ; with the () notation meaning the expansion is onstru ted via on atenation of registers. Now with numbers su h as 2 3 we have b-normal numbers that are \natural" in the sense that they an be des ribed via some kind of analyti formulation. Su h talk is of ourse heuristi ; the rigor omes in the theorems of the following se tions. ;
2
In addition to the normality theorems appli able to the restri ted sums mentioned above, we present a olle tion of additional results on irrationality and b-density (see ensuing de nitions). These side results have arisen during our resear h into the PRNG
onne tion.
2. Nomen lature and fundamentals We rst give some ne essary nomen lature relevant to base-b expansions. For a real number 2 [0; 1) we shall assume uniqueness of base-b digits, b an integer 2; i.e. = 0:b1b2 with ea h b 2 [0; b 1℄, with a ertain termination rule to avoid in nite tails of digit values b 1. One way to state the rule is simply to de ne b = bb ; another way is to onvert a trailing tail of onse utive digits of value b 1, as in 0:4999 ! 0:5000 for base b = 10. Next, denote by f g, or mod 1, the fra tional part of , and denote by jj jj the loser of the absolute distan es of mod 1 to the interval endpoints 0; 1; i.e. jj jj = min(f g; 1 f g). Denote by ( ) the ordered sequen e of elements 0; 1; : : :. Of interest will be sequen es ( ) su h that (f g) is equidistributed in [0; 1), meaning that any subinterval [u; v ) [0; 1) is visited by f g for a (properly de ned) limiting fra tion (v u) of the n indi es; i.e., the members of the sequen e fall in a \fair" manner. We sometimes onsider a weaker ondition that (fa g) be merely dense in [0; 1), noting that equidistributed implies dense. Armed with the above nomen lature, we paraphrase from [3℄ and referen es [27℄ [21℄ [33℄ [25℄ in the form of a olle tive de nition: De nition 2.1 (Colle tion) The following pertain to real numbers and sequen es of real numbers ( 2 [0; 1) : n = 0; 1; 2; : : :). For any base b = 2; 3; 4 : : : we assume, as enun iated above, a unique base-b expansion of whatever real number is in question. j
j
j
n
n
n
n
n
n
1. is said to be b-dense i in the base-b expansion of every possible nite string of
onse utive digits appears. 2. is said to be b-normal i in the base-b expansion of every string of k base-b digits appears with (well-de ned) limiting frequen y 1=b . A number that is b-normal for every b = 2; 3; 4; : : : is said to be absolutely normal. (This de nition of normality di ers from, but is provably equivalent to, other histori al de nitions [21℄ [33℄.) k
3. The dis repan y of ( ), essentially a measure of unevenness of the distribution in [0; 1) of the rst N sequen e elements, is de ned (when the sequen e has at least N elements) n
D
N
=
sup
0
a 1 we have k = 364 1093k 2 . (Thus for example the order of 2 modulo 10932 is also 364.) Remark 2. One ould attempt to expand the (b; p)-PRNG de nition to in lude the even-modulus ase pk = 2k , with odd b 3, in whi h ase the rules run like so: If 2k j(b 1) then the order is k = 1, else if 2k j(b2 1) then k = 2, else de ne a by 2a jj(b2 1), when e the order is k = 21+k a . One expe ts therefore that normality results would a
rue for a (b; 2)-PRNG system, odd b 3. However we do not travel this path in the present treatment; for one thing some of the lemmas from the literature are geared toward odd prime powers, so that more details would be required to in lude p = 2 systems. The perturbation rn for a (b; p)-PRNG system is thus of the \ki king" variety; happening inde nitely, but not on every iteration, and in fa t, happening progressively rarely. Between the \ki ks," iterates of the sequen e are, in e e t, repetitions of a ertain type of
9
normalized linear ongruential PRNG. This is best seen by examining a spe i example. Consider su
essive iterates of the (2; 3)-PRNG system, whose iterates run like so: (x0;
x1 ; : : : ; x26 ; : : :)
= (0;
13
26
11
27 40 81
;
27
;
25 27
;
23 27
;
19 27
;
27
;
1
;
2
;
3 3 22 17
27
;
27
;
4
8
;
;
7
9 9 9 7 14 27
;
27
;
;
5 9 1
;
27
;
1
;
2
;
9 9 2 4 27
;
27
;
8 27
;
16 27
;
5 27
;
10 27
;
20 27
;
; )
A pattern is lear from the above: The entire sequen e is merely (after the initial 0) a on atenation of subsequen es of respe tive lengths 2 3k 1 , for k = 1; 2; : : :. Ea h subsequen e is the omplete period of a ertain linear ongruential PRNG normalized by 3k . Note that sin e 2 is a primitive root modulo 3k ; k > 0, ea h subsequen e visits, exa tly on e, every integer in [1; 3k 1℄ that is oprime to 3. In general, we an write the following (for simpli ity we use simply to mean equality on the mod-1 ir le):
0; b 0 + r 1p ; b x ; p
x0 x1
1
2
::: ; bp 2 xp 1 ; p p+1 bp 1 + rp ; xp p p2 ::: ; bp2 p 1 (p + 1) xp2 1 ; p2 p2 + p + 1 bp(p 1)(p + 1) 2 = + r ; xp2 p p2 p3 ::: ; and generally speaking,
xpk
1
k (p
1)=(p
p
k
1)
:
It is evident that upon the 1=pk perturbation, the xn ommen e a run of length '(pk ) = pk 1 (p 1) before the next perturbation, a
ording to the following rule: The subsequen e (xpk 1 ; : : : ; xpk 1 ) runs from
ak b0 mod pk =pk 10
through
pk ak b
1 (p 1) 1
mod pk =pk
in lusive, where ak
=
pk p
1 1
is oprime to p. One is aware that, in general, this subsequen e will repeat | i.e., \walk on itself" | unless b is a primitive root of pk . This phenomenon o
urs, of ourse, be ause the powers of b modulo pk have period k whi h period an be less than '(pk ). Later we shall use the symbol Mk to be the multipli ity of these subsequen e orbits; Mk = '(pk )= k . For the moment we observe that the Mk are bounded for all k , in fa t Mk < pa always. We need to argue that (xn ) is equidistributed. For this we shall require an important lemma on exponential sums, whi h lemma we hereby paraphrase using our (b; p)-PRNG nomen lature:
Lemma 4.2 (Korobov, Niederreiter) Given b 2; g d(b; p) = 1, and p an odd prime (so that the order of b modulo pk is k of the text), assume positive integers k; H; J and d = g d(H; pk ) with J k and d < k = 1 . Then
J X j k 2iHb =p e j =1
r
2a,
log2 '
p'
1) terms, has dis repan y satisfying
;
where C is a onstant depending only on (b; p) (and thus k -independent).
p
Su h O(log 2 N= N ) results in luding some results on best-possibility of su h bounds, have been a hieved in brilliant fashion by Niederreiter (see [30℄, p. 1009 and [31℄, pp. 169-170). Su h results have histori ally been applied to generators of long period, e.g. PRNGs that have long period for the given modulus. Evidently the only statisti al drawba k for the PRNGs of present interest is that the dis repan y-bound onstant an be rather large (and, of ourse, we need eventually to hain our PRNG subsequen es together to obtain an overall dis repan y). Remark.
Proof.
By the Erd}os{Turan Theorem 2.2(9), for any integer mk 0
D'
< C1
1 mk
+
m
k X
k 1 1 Mk X
h=1 h
' j =0
e
2ihak
>
0 we have
1
bj =pk
A
;
where Mk is the multipli ity '= k that des ribes how many omplete y les the given subsequen e performs moduloppk . When h < k = 1 = pk a the j j term is, by Lemma 4.2, less than C2 (1 + log k )= k . Choosing mk = bpk=2 < pk ap onstrains the index p h properly, and we obtain D' < C3 (1= mk + (log(mk ) log k )= k ). Now we re all p p that Mk = '= k is bounded and observe that C4 ' < mk < C5 ', and the desired dis repan y bound is met. Finally we an address the issue of equidistribution of the (b; p)-PRNG system, by
ontemplating the hain of subsequen es that onstitute the full generator: Theorem 4.5
DN
For the full (b; p)-PRNG sequen e (xn ), the dis repan y for N
< C
log2 N
p
N
>
1 satis es
;
where C is independent of N , and a
ordingly, (xn ) is equidistributed.
Let N = '(p) + '(p2 ) + + '(pk 1 ) + J = pk 1 1 + J be the index into the full (xn ) sequen e, where 0 < J < '(pk ), so that we have (k 1) omplete mod-pi
Proof.
12
subsequen es, then J initial terms from a last subsequen e having denominator pk . Also let k > 2a + 1 so that Lemma 4.4 is e e tive. By Lemma 4.3 and the Erd}os{Turan Theorem 2.2(9) we have for any positive integer m 2a
DN
2a + 1) we have:
C3 N < pk < N; C5 N i=k < '(pi ) < C6 N i=k ; C7 N < k < C8N; where the various Cj here are k -and-i-independent, positive onstants. Next, hoose the parameter m = bpk=2 . Now the desired dis repan y bound follows upon repla ement of all pk ; '(pi ); k terms with onstants times powers of N . That (xn ) is equidistributed is a onsequen e of Theorem 2.2(12). Now we an move to the main result For base b > 1 and odd prime p oprime to b, the number
Theorem 4.6
b;p =
X
n1
1
pn bpn
is b-normal.
When b is a primitive root of p and pjj(bp 1 1), it is easy to show that this b;p is b-dense (the (b; p)-PRNG sequen e be omes progressively ner in an obvious way). Proof. For a (b; p)-PRNG system the asso iated onstant as in Theorem 3.1 is = P k pk 1 ) and this is a rational multiple of our . Theorem 2.2(7) nishes the b;p k1 1=(p b argument. Remark.
Corollary 4.7
2;3 =
The number
1 n2n n=3k >1 X
is 2-normal. 13
It is natural to ask whether b;p is trans endental, whi h question we answer in the positive with: Theorem 4.8 The number b;p for any integers b > 1; p > 2 is trans endental. Remark. Though b;p has been introdu ed for (b; p)-PRNG systems with b > 1; g d(b; p) = 1, p an odd prime, the trans enden y result is valid for any integer pair (b; p) with p > 2 and b > 1. Proof. The elebrated Roth theorem states [36℄ [13℄ that if jP=Q j < 1=Q2+ admits of in nitely many rational solutions P=Q (i.e. if is approximable to degree 2 + for some > 0), then is trans endental. We show here that b;p is approximable to degree p Æ . Fix a k and write 1 ; b;p = P=Q + n pn
X
n>k
pb
k
where g d(P; Q) = 1 with Q = pk bp . The sum over n gives
j b;p
P=Qj
d 2
fxdg = ff2dE g + f
j
E
1
1
1 A mod 1;
1 + td gg;
where td ! 0. Thus f2d E g is equidistributed i (xn ) is, by Theorem 2.2(10). We believe that at least a weaker, density onje ture should be assailable via the kind of te hnique exhibited in Theorem 5.1, whereby one pro eeds onstru tively, establishing density by for ing the indi ated generator to approximate any given value in [0; 1). P. Borwein has forwarded to us an interesting observation on a possible relation between the number E and the \prime-tuples" postulates, or the more general Hypothesis H of S hinzel and Sierpinski. The idea is | and we shall be highly heuristi here | the 20
fra tional part d(m + 1)=2 + d(m + 2)=22 + might be quite tra table if, for example, we have + 1 = p1 ; m+2 = 2p2 ;
m
::: m
+n =
; npn ;
at least up to some n = N . where the pi > N are all primes that appear in an appropriate \ onstellation" that we generally expe t to live very far out on the integer line. Note that in the range of these n terms we have d(m + j ) = 2d(j ). Now if the tail sum beyond N is somehow suÆ iently small, we would have a good approximation d(m + N )=2 2m E g
f
(1) + d(2)=2 + = 2E :
d
But this implies in turn that some iterate f2m E g revisits the neighborhood of an earlier iterate, namely f2E g. It is not lear where su h an argument|espe ially given the heuristi aspe t|should lead, but it may be possible to prove 2-density (i.e. all possible nite bitstrings appear in E ) on the basis of the prime k -tuples postulate. That onne tion would of ourse be highly interesting. Along su h lines, we do note that a result essentially of the form: \The sequen e (f2m E g) ontains a near-miss (in some appropriate sense) with any given element of (fnE g)" would lead to 2-density of E , be ause, of ourse, we know E is irrational and thus (fnE g) is equidistributed.
6. Spe ial numbers having \nonrandom" digits This se tion is a tour of side results in regard to some spe ial numbers. We shall exhibit numbers that are b-dense but not b-normal, un ountable olle tions of numbers that are neither b-dense nor b-normal, and so on. One reason to provide su h a tour is to dispel any belief that, be ause almost all numbers are absolutely normal, it should be hard to use algebra (as opposed to arti ial onstru tion) to \point to" nonnormal numbers. In fa t it is not hard to do so. First, though, let us revisit some of the arti ially onstru ted normal numbers, with a view to reasons why they are normal. We have mentioned the binary Champernowne, whi h an also be written C2
=
X1
n=1
n
2F (n)
where the indi ated exponent is: ( ) =
F n
X log + n
n
k=1
b
2 k :
Note that the growth of the exponent F (n) is slightly more than linear. It turns out that if su h an exponent grows too fast, then normality is ruined. More generally, there is the 21
lass of Erd}os{Copeland numbers [14℄, formed by (we remind ourselves that the () notation means digits are on atenated, and here we on atenate the base-b representations)
= 0:(a1)b (a2)b
where (an ) is any in reasing integer sequen e with an = O(n1+ ), any > 0. An example of the lass is 0:(2)(3)(5)(7)(11)(13)(17) 10 ; where primes are simply on atenated. These numbers are known to be b-normal, and they all an be written in the form G(n)=bF (n) for appropriate numerator fun tion G and, again, slowly diverging exponent F . We add in passing that the generalized Mahler numbers (for any g; h > 1)
P
Mb (g ) = 0:(g 0 )b (g 1 )b (g 2 )b
are known at least to be irrational [32℄, [38℄, and it would be of interest to establish perturbation sums in regard to su h numbers. In identally, it is ironi that the some of the methods for establishing irrationality of the Mb (g ) are used by us, below, to establish nonnormality of ertain forms. We have promised to establish that
=
X n=2
n2
n 1
is 2-dense but not 2-normal. Indeed, in the n2 -th binary position we have the value n, and sin e for suÆ iently large n we have n2 (n 1)2 > 1 + log2 n, the numerator n at bit position n2 will not interfere (in the sense of arry) with any other numerator. One may bury a given nite binary string in some suÆ iently large integer n (we say buried be ause a string 0000101, for example, would appear in su h as n = 10000101), when e said string appears in the expansion. Note that the divergen e of the exponent n2 is a key to this argument that is 2-dense. As for the la k of 2-normality, it is likewise evident that almost all bits are 0's. Let is hereby onsider faster growing exponents, to establish a more general result, yielding a lass of b-dense numbers none of whi h are b-normal. We start with a simple but quite useful lemma. For polynomials P with nonnegative integer oeÆ ients, deg P > 0, and for any integer b > 1, the sequen e Lemma 6.1
(flogb P (n)g : n = 1; 2; 3; : : :)
is dense in [0; 1). Proof. For d = deg P , let P (x) = ad xd + : : : + a0 . Then logb P (n) = logb ad + d(log n)= log b + O(1=n). Sin e log n = 1 + 1=2 + 1=3 + : : : + 1=n + O(1=n2 ) diverges with n but by vanishing in rements, the sequen e (fd(log n)= log bg) and therefore the desired (flogb P (n)g) are both dense by Theorem 2.2(10). 22
Now we onsider numbers onstru ted via superposition of terms P (n)=bQ(n) , with a growth ondition on P; Q: Theorem 6.2
0, the number
=
For polynomials P; Q with nonnegative integer oeÆ ients, deg Q > deg P >
X P (n) Q(n) b
n 1
is b-dense but not b-normal. Proof. The nal statement about nonnormality is easy: Almost all of the base-b digits are 0's, be ause logb P (n) = o(Q(n) Q(n 1)). For the density agrument, we shall show that for any r 2 (0; 1) there exist integers N0 < N1 < : : : and d1 ; d2 ; : : : with Q(Nj 1 ) < dj < Q(Nj ), su h that lim fbdj g = r: !1
j
This in turn implies that (fbd g) : d = 1; 2; : : :g) is dense, hen e is b-dense. Now for any as ending hain of Ni with N0 suÆ iently large, we an assign integers dj a
ording to
Q(Nj ) > dj = Q(Nj ) + logb r logb P (Nj ) + j > Q(Nj 1 ) where j
2 [0; 1). Then
P (Nj )=bQ(Nj )
dj
= 2j r:
However, (flogb P (n)g) is dense, so we an nd an as ending Nj - hain su h that lim j = 0. Sin e dj < Q(Nj ) we have
fbd g j
=
0 b r + X P (Nj + k)=bQ N (
j
j +k )
1 d A j
mod 1
k>0
and be ause the sum vanishes as j
! 1, it follows that is b-dense.
Consider the interesting fun tion [27℄, p. 10: 1 bnx X f (x) = : n n=1 2 The fun tion f is reminis ent of a degenerate ase of a generalized polylogarithm form| that is why we en ountered su h a fun tion during our past [3℄ and present work. Regardless of our urrent onne tions, the fun tion and its variants have ertainly been studied, espe ially in regard to ontinued fra tions [16℄ [17℄ [27℄ [8℄ [29℄ [5℄ [1℄ [17℄ [9℄, [10℄. If one 23
plots the f fun tion over the interval x 2 [0; 1), one sees a brand of \devil's stair ase," a
urve with in nitely many dis ontinuities, with verti al-step sizes o
urring in a fra tal pattern. There are so many other interesting features of f that it is eÆ ient to give another olle tive theorem. Proofs of the harder parts an be found in the aforementioned referen es. Theorem 6.3 (Colle tion)
the argument x 2 (0; 1),
For the \devil's stair ase" fun tion
f
de ned above, with
1.
f
is monotone in reasing.
2.
f
is ontinuous at every irrational x, but dis ontinuous at every rational x.
3. For rational
x
= p=q , lowest terms, we have
( ) =
f x
2q
1
1
1 X +
m=1
1 b m=x
2
but when x is irrational we have the same formula without the 1=(2q term (as if to say q ! 1).
4. For irrational x = [a1; a2; a3; : : :℄, a simple ontinued fra tion with onvergents (pn =qn ), we have: ( ) = [A1; A2; A3; : : :℄:
f x
where the elements An are: An
= 2qn
2
2an qn 1 1 : 2qn 1 1
Moreover, if (Pn =Qn ) denote the onvergents to f (x), we have Qn
= 2qn
1:
5. f (x) is irrational i
x
is.
6. If x is irrational then f (x) is trans endental. 7. f (x) is never 2-dense and never 2-normal. 8. The range
R=
f
([0; 1)) is a null set (measure zero).
9. The density of 1's in the binary expansion of f (x) is inverse fun tion on the range R, is just 1's density. 24
x
itself; a
ordingly, f 1 , the
Some ommentary about this fas inating fun tion f is in order. We see now how f an be stri tly in reasing, yet manage to \ ompletely miss" 2-dense (and hen e 2-normal) values: Indeed, the dis ontinuities of f are dense. The notion that the range R be a null set is surprising, yet follows immediately from the fa t that almost all x have 1's density equal to 1=2. The beautiful ontinued fra tion result allows extremely rapid omputation of f values. The fra tion form is exempli ed by the following evaluation, where x is the re ipro al of the golden mean and the Fibona
i numbers are denoted F : i
!
2 p 1+ 5 = [2 0 ; 2 1 ; 2 2 ; : : :℄ 1 ; = 1 + 2+ 1 1
f (1= ) = f
F
F
F
2 4+ 1 1 8+
:::
It is the superexponential growth of the onvergents to a typi al f (x) that has enabled trans enden y proofs as in Theorem 6.2(6). An interesting question is whether (or when) a ompanion fun tion
g (x) =
1 fnxg X n=1
2
n
an attain 2-normal values. Evidently
g (x) = 2x f (x); and, given the established nonrandom behavior of the bits of f (x) for any x, one should be able to establish a orrelation between normality of x and normality of g (x). One reason why this question is interesting is that g is onstru ted from \random" real values fnxg (we know these are equidistributed) pla ed at unique bit positions. Still, we did look numeri ally at a spe i irrational argument, namely
x =
X
1 2
1 n(n+1)=2
n
and noted that g (x) almost ertainly is not 2-normal. For instan e, in the rst 66,420 binary digits of g (x), the string '010010' o
urs 3034 times, while many other length-6 strings do not o
ur at all. 7. Con lusions and open problems
Finally, we give a sampling of open problems pertaining to this interdis iplinary e ort:
We have shown that for (b; p)-PRNG systems, the numbers are ea h b-normal. What about -normality of su h a number for not a rational power of b? b;p
25
WhatP te hniques might allow is to relax the onstraint of rapid growth n = p in our sums 1=(nb ), in order to approa h the spe ta ular goal of resolving the suspe ted b-normality of log(b=(b 1))? One promising approa h is to analyze dis repan y for relatively short parts of PRNG y les. In [25℄, p. 171, [26℄ there appear exponential sum bounds for relatively short indi es J into the last y le. It ould be that su h theorems an be used to slow the growth of the summation index n.
It is lear that the dis repan y bound given in Theorem 4.5, based in turn on the Korobov{Niederreiter Lemma 4.2, is \overkill," in the sense that we only need show D = o(N ) to a hieve a normality proof. Does this mean that the numbers are somehow \espe ially normal"? For su h a question one would perhaps need extra varian e statisti s of a normal number; i.e., some measures beyond the \fair frequen y" of digit strings.
k
n
N
b;p
We have obtained rigorous results for PRNGs that either have a ertain syn hronization, or have extremely small \tails." What te hniques would strike at the intermediate s enario whi h, for better or worse, is typi al for fundamental onstants; e.g., the onstants falling under the umbrella of Hypothesis A?
With our (b; p)-PRNG systems we have established a ountable in nity of expli it b-normal numbers. What will it take to exhibit an un ountable, expli it olle tion?
What are the properties of \ ontra ted" PRNGs, as exempli ed in Se tion 4? Does polynomial-time (in log n) resolution of the n-th digit for our onstants give rise to some kind of \trap-door" fun tion, as is relevant in ryptographi appli ations? The idea here is that it is so very easy to nd a given digit even though the digits are \random." (As in: Multipli ation of n-digit numbers takes polynomial time, yet fa toring into multiples is evidently very mu h harder.) b;p
8. A knowledgments
The authors are grateful to J. Borwein, P. Borwein, D. Bowman, D. Broadhurst, J. Buhler, D. Copeland, H. Ferguson, M. Ja obsen, J. Lagarias, R. Mayer, H. Niederreiter, S. Plou e, A. Pollington, C. Pomeran e, J. Shallit, S. Wagon, T. Wieting and S. Wolfram for theoreti al and omputational expertise throughout this proje t. We would like to dedi ate this work to the memory of Paul Erd}os, whose ingenuity on a ertain, exoti analysis dilemma|the hara ter of the Erd}os{Borwein onstant E |has been a kind of guiding light for our resear h. When we oauthors began|and this will surprise no one who knows of Erd}os|our goals were presumed unrelated to the Erd}os world. But later, his way of thinking meant a great deal. Su h is the persona of genius, that it an speak to us even a ross robust boundaries.
26
Referen es [1℄ W. W. Adams and J. L. Davison, \A remarkable lass of ontinued fra tions," Pro eedings of the Ameri an Mathemati al So iety, 65, 1977, 194-198. [2℄ David H. Bailey, Peter B. Borwein and Simon Plou e, \On The Rapid Computation of Various Polylogarithmi Constants," Mathemati s of Computation, vol. 66, no. 218, 1997, pp. 903{913. [3℄ David H. Bailey and Ri hard E. Crandall, \On the random hara ter of fundamental
onstant expansions," Experimental Mathemati s, 10, 2001, 175-190. [4℄ Beeler, M. et al. Item 120 in Beeler, M.; Gosper, R. W.; and S hroeppel, R., \HAKMEM," Cambridge, MA: MIT Arti ial Intelligen e Laboratory, Memo AIM-239, p. 55, Feb. 1972. [5℄ P. E. Bohmer,\Uber die Transzendenz gewisser dyadis her Bru he," Mathemati he Annalen, 96, 1926, 367-377, Erratum: 96, 1926, 735 [6℄ J. Borwein, D. Bradley and R. Crandall, \Computational Strategies for the Riemann Zeta Fun tion," manus ript, De . 1998, www. e m.sfu. a/preprints/1998pp.html [7℄ Peter Borwein, \On the irrationality of ertain series," Mathemati al Pro eedings of the Cambridge Philosophi al So iety, vol. 112 (1992), pg. 141-146; MR 93g:11074. [8℄ Jonathan Borwein and Peter Borwein, \On the Generating Fun tion of the Integer Part of bn + ," Journal of Number Theory, 43, 1993, 293-318. [9℄ Douglas Bowman, \Approximation of bn + s and the zero of fn + sg," Journal of Number Theory, 50, 128-144 (1995) [10℄ Douglas Bowman, \A New Generalization of Davison's Theorem," Fibona
i Quarterly, 26, 40-45 (1988) [11℄ David J. Broadhurst, \Polylogarithmi Ladders, Hypergeometri Series and the Ten Millionth Digits of (3) and (5)," preprint, Mar h 1998. The manus ript is available from the URL http://xxx.lanl.gov/abs/math/9803067. [12℄ David J. Broadhurst, \Conje ture on Integer-Base Polylogarithmi Zeros Motivated by the Cunningham Proje t", manus ript, Mar h 2000. [13℄ J. W. S. Cassels, An introdu tion Press, Cambridge, 1957.
to diophantine approximations, Cambridge Univ.
[14℄ A. H. Copeland and P. Erd}os, \Note on Normal Numbers," Bulletin Ameri an Mathemati al So iety, vol. 52 (1946), pg. 857{860. [15℄ R. Crandall, Topi s in Advan ed S ienti Computation, Springer-Verlag, 1996. 27
[16℄ L. V. Danilov, \Some lasses of trans endental numbers," Matemati heskie Zametki, 12, 1972, 149-154; In Russian, English translation in Mathemati al Notes of the A ademy of S ien e of the USSR 12, 1972, 524{527. [17℄ J. L. Davison, \A series and its asso iated ontinued fra tion," Ameri an Mathemati al So iety, 63, 1977, 29-32. [18℄ Robert L. Devaney,
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Complex Dynami al Systems: The Mathemati s Behind the
Mandelbrot and Julia Sets,
Ameri an Mathemati al So iety, Providen e, 1995.
[19℄ P. Erd}os. \On Arithmeti al Properties of Lambert Series," Mathemati al So iety (N.S.), vol. 12 (1948), pg. 63{66.
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[20℄ Helaman R. P. Ferguson, David H. Bailey and Stephen Arno, \Analysis of PSLQ, An Integer Relation Finding Algorithm," Mathemati s of Computation, vol. 68, no. 225 (Jan. 1999), pg. 351-369. [21℄ G. H. Hardy and E. M. Wright, University Press, 1979.
An Introdu tion to the Theory of Numbers,
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[22℄ Mark Ja obsen, private ommuni ation (2000). Ja obsen in turn referen es Herbert Solomon, Geometri Probabilities, SIAM, Philadelphia, 1978. [23℄ A. Khin hin, Continued
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[24℄ Donald E. Knuth, The Art of Computer Addison-Wesley, Menlo Park, 1981. [25℄ N. Korobov, 1992.
Programming,
Exponential Sums and their Appli ations,
vol. 2, se ond edition,
Kluwer A ademi Publishers,
[26℄ N. Korobov, \On the distribution of digits in periodi fra tions," USSR Sbornik, 18, 1972, 659-676. [27℄ L. Kuipers and H. Niederreiter, Inters ien e, New York, 1974.
Matemati heskie
Uniform Distribution of Sequen es,
Wiley-
[28℄ J. Lagarias, \On the Normality of Fundamental Constants," Experimental Mathemati s, Vol. 10, No. 3, 353{366 (2001). [29℄ R. Mayer, private ommuni ation (2000). [30℄ H. Niederreiter, \Quasi-Monte Carlo Methods and Pseudo-Random Numbers," Bull. Amer. Math. So . 84, 6, (1978). [31℄ H. Niederreiter, \Random Number Generation and Quasi-Monte Carlo Methods," CBMS-NSF Regional Conferen e Series in Applied Mathemati s, SIAM, 63, (1992).
28
[32℄ H. Niederreiter, \On an irrationality theorem of Mahler and Bunds huh," J. Number Theory 24, 197-199 (1986). [33℄ I. Niven, Irrational York (1956). [34℄ C.
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2022-05-19 21:57:06
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https://lubricants-ils.com.au/product/kluber-summit-ngsh-100/
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# Klüber Summit NGSH 100
Klüber Summit NGSH 100 is a synthetic gas compressor lubricant.
– For the lubrication of rotary screw and reciprocating compressors in natural gas service
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#### Description
Klüber Summit NGSH lubricants are based on synthetic hydrocarbons and special additives. They protect compressors against wear, rust and hydrogen sulphide corrosion.
#### Application
Klüber Summit NGSH are designed for rotary screw and reciprocating compressors in natural gas service. Due to the varying make-up of gases and operating conditions, please contact your local Klüber representative for specific product recommendations.
#### Application notes
Drain as much of the previously used compressor oil from the system as possible, making sure that the oil is drained while still warm. Do not forget to drain coolers, separator tanks and all lines. Afterwards clean or change the filter, then recharge with the Klüber Summit NGSH operational lubricant.
We recommend attaching a label indicating the type of lubricant used and the filling date to the filter or the cover.
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2019-06-18 17:49:09
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https://www.physicsforums.com/threads/extended-real-valued-function.413101/
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# Extended real-valued function
1. Jun 28, 2010
### wayneckm
Hello all,
Recently I came across the following statement:
What happens when a convex function f achieves the value −1 at some point xo? Usually, a degenerate behaviour occurs. For instance, suppose that f is defined on R, and f(0) =
− infinity. If f(1) is finite (say), then one must have f(x) = −1 for all 0 <= x < 1 and f(x) = +infinity for all x > 1.
Apparently there is no restriction on the function characteristics, e.g. continuity, on f, why is it a "MUST"? If f is continuous (is this allowed for extended real-valued function?), it seems this is not a "MUST".
Or please kindly advise me on the definition of extended real-valued function as well as its characteristics.
Thanks very much.
2. Jun 28, 2010
### Hurkyl
Staff Emeritus
Surely there's at least one typo in there?
Anyways, I don't think the term "convex function" really makes sense in this context.
3. Jun 28, 2010
### wayneckm
Oops, I think I omiited the assumption of convexity in f.
For $$0 \leq \alpha < 1$$, by convexity, we have $$f(\alpha) \leq \alpha f(0) + (1-\alpha) f(1) \; \Rightarrow \; f(\alpha) \leq -\infty$$, so we deduce that $$f(x) = -\infty \quad \forall x \in [0,1)$$
Similarly we can prove $$f(x) = +\infty \quad \forall x \in (1,+\infty)$$ otherwise it would violate the assumption of convexity, in particular at $$f(1)$$ which is finite.
4. Jun 28, 2010
### Hurkyl
Staff Emeritus
Alas, convexity is violated anyways: we have now shown the right hand side of
$$f(1) \leq (1/2) f(0) + (1/2) f(2)$$
must be undefined. (being of the form $(+\infty) + (-\infty)$)
5. Jun 28, 2010
### wayneckm
So it seems the results rely on whether one define the operation $$+\infty + -\infty$$? And are we free to define this kind of operation in the extended real number system?
6. Jun 28, 2010
### Hurkyl
Staff Emeritus
In the extended real number system, $(+\infty) + (-\infty)$ is undefined.
There is, of course, nothing stopping you from defining a different number system in whatever way you like whose numbers are extended real numbers.
More fruitful is to come up with an appropriate definition for the extended reals, rather than try to force a definition meant for standard reals to work.
Now that I think more about it, I suspect "convex function" really is a reasonable notion for extended real numbers. I would guess its definition would be equivalent to:
f is convex iff the set of all real numbers (x,y) satisfying $y \geq f(x)$ is a convex subset of the plane
(One could write an equivalent definition in terms of the algebraic identity you used, but with ad hoc additions to treat the cases where the function is somewhere infinite)
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2017-10-19 01:56:38
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https://scentersupply.com/earl-grey/manual-solution-for-square-root.php
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# Earl Grey Manual Solution For Square Root
## For Exercise simplify the squares and square roots. (See
### Java Calculate Square Root Without Using Library Method
What is the square root formula? Answers. C++ program to find Square Root of a Number. For calculate Square Root of a number we multiply number by 0.5 because square root of any number means power of 1/2 and 1/2=0.5. And one another method for this program is use sqrt() function it is pre-defined in math.h header file., numpy.roots¶ numpy.roots (p) [source] ¶ Return the roots of a polynomial with coefficients given in p. The values in the rank-1 array p are coefficients of a polynomial. If the length of p is n+1 then the polynomial is described by:.
### Solved Using the Square Root Property solve the equation
How to Calculate Square Root Without Calculator YouTube. numpy.roots¶ numpy.roots (p) [source] ¶ Return the roots of a polynomial with coefficients given in p. The values in the rank-1 array p are coefficients of a polynomial. If the length of p is n+1 then the polynomial is described by:, You are here: Home → Articles → Square Root Algorithm How to calculate a square root without a calculator and should your child learn how to do it. Most people in today's world feel that since calculators can find square roots, that children don't need to learn how to find square roots using any pencil-and-paper method..
B = sqrt(X) returns the square root of each element of the array X. For the elements of X that are negative or complex, sqrt(X) produces complex results. The sqrt function’s domain includes negative and complex numbers, which can lead to unexpected results if used unintentionally. C++ program to find Square Root of a Number. For calculate Square Root of a number we multiply number by 0.5 because square root of any number means power of 1/2 and 1/2=0.5. And one another method for this program is use sqrt() function it is pre-defined in math.h header file.
When using math root rules, first note that you can’t have a negative number under a square root or any other even number root — at least, not in basic calculus. Here are a couple of easy rules to begin with: But you knew that, right? To multiply roots: To divide roots: To find the […] 05/02/2020 · How to Calculate a Square Root by Hand. In the days before calculators, students and professors alike had to calculate square roots by hand. Several different methods have evolved for tackling this daunting process, some giving a rough...
05/02/2020 · How to Calculate a Square Root by Hand. In the days before calculators, students and professors alike had to calculate square roots by hand. Several different methods have evolved for tackling this daunting process, some giving a rough... Chapter 6 Exercise 22, Introduction to Java Programming, Tenth Edition Y. Daniel LiangY. **6.22 (Math: approximate the square root) There are several techniques …
Solve Equations With Square Root (√) Tutorial on how to solve equations containing square roots.Detailed solutions to examples, explanations and exercises are included. The main idea behind solving equations containing square roots is to raise to power 2 in order to clear the square root … Mathematics Solutions Solutions for Class 6 Math Chapter 9 Square And Square Roots are provided here with simple step-by-step explanations. These solutions for Square And Square Roots are extremely popular among Class 6 students for Math Square And Square Roots Solutions come handy for quickly completing your homework and preparing for exams.
The values whose square-roots are required. out: ndarray, None, or tuple of ndarray and None, optional. A location into which the result is stored. If provided, it must have a shape that the inputs broadcast to. If not provided or None, a freshly-allocated array is returned. A tuple (possible only as a keyword argument) must have length equal Square Root Solutions is a veteran mobile app development company, which provides comprehensive mobile app development services in Ireland for a number of domains. It is crystal clear that with the immense demand of mobile apps, businesses are seeking out for effective and efficient mobile app development partner companies to aid them in the development process.
08/05/2017 · When we find solution set of an equation inside a square root why we should assume that inside of square root should be equal to or greater than zero? For example ##\\sqrt{5x-4}##. How can I use here equal to or greater than zero symbol? Thank you. When using math root rules, first note that you can’t have a negative number under a square root or any other even number root — at least, not in basic calculus. Here are a couple of easy rules to begin with: But you knew that, right? To multiply roots: To divide roots: To find the […]
Although the principal square root of a positive number is only one of its two square roots, the designation "the square root" is often used to refer to the principal square root. For positive x, the principal square root can also be written in exponent notation, as x 1/2. The Square Roots chapter of this SAT Mathematics Level 2 Tutoring Solution is a flexible and affordable path to learning about square roots. These simple and fun video lessons are each about five
Square Root Solutions is a veteran mobile app development company, which provides comprehensive mobile app development services in Ireland for a number of domains. It is crystal clear that with the immense demand of mobile apps, businesses are seeking out for effective and efficient mobile app development partner companies to aid them in the development process. home / study / math / algebra / algebra solutions manuals / Prealgebra / 2nd edition / chapter 8.6 / problem 32PE. Prealgebra (2nd Edition) Edit edition. Problem 32PE from Chapter 8.6: For Exercise, simplify the squares and square roots. (See Ex... Get solutions . Looking for the textbook? We have solutions for your book! Chapter:
B = sqrt(X) returns the square root of each element of the array X. For the elements of X that are negative or complex, sqrt(X) produces complex results. The sqrt function’s domain includes negative and complex numbers, which can lead to unexpected results if used unintentionally. Excel's powerful mathematical toolkit includes functions for square roots, cube roots, and even nth roots. Our review of these techniques will focus on the manual entry of formulas, but check out our tutorial on using Excel if you need a refresher on formula entry for core functions.
What is the solution for square root of 27? Unanswered Questions. Why high rainfall areas face water shortage? What are the drawbacks of Newland's law of octaves? What areas of Miami are How to manually find a square root Here is an almost-forgotten art: one that, with the advent of electronic calculators, will likely survive to the twenty-first century only on paper and in the memories of oldsters.
The formula of square root is basic once you learn it. To figure out the square root of a number you must know what a square number is. A square number is the product of a multiplication problem Solving square-root equations: one solution Our mission is to provide a free, world-class education to anyone, anywhere. Khan Academy is a 501(c)(3) nonprofit organization.
Square Root 123https Www Sas Com En Us Solutions Ai Html.pdf - search pdf books free download Free eBook and manual for Business, Education,Finance, Inspirational, Novel, Religion, Social, Sports, Science, Technology, Holiday, Medical,Daily new PDF ebooks documents ready for download, All PDF documents are Free,The biggest database for Free books and documents search with fast results better Return Values. The square root of arg or the special value NAN for negative numbers.
Solve Equations With Square Root (√) Tutorial on how to solve equations containing square roots.Detailed solutions to examples, explanations and exercises are included. The main idea behind solving equations containing square roots is to raise to power 2 in order to clear the square root … Represented by a radical symbol $\sqrt{}$ “ Square Root” is often used to refer to the principal square root. For example, 4 and -4 are the square roots of 16 because 4 2 is 16. $\LARGE \sqrt[n]{x}=x^{\frac{1}{n}}$ In order to calculate the square root, we first need to find the factors of a given number, then group the common factor
Solving square-root equations: one solution Our mission is to provide a free, world-class education to anyone, anywhere. Khan Academy is a 501(c)(3) nonprofit organization. Methods of computing square roots are numerical analysis algorithms for finding the principal, or non-negative, square root (usually denoted в€љ S, 2 в€љ S, or S 1/2) of a real number.
The Square Roots chapter of this SAT Mathematics Level 2 Tutoring Solution is a flexible and affordable path to learning about square roots. These simple and fun video lessons are each about five squares and square roots Mathematics Solutions Solutions for Class 8 Math Chapter 1 Squares And Square Roots are provided here with simple step-by-step explanations. These solutions for Squares And Square Roots are extremely popular among Class 8 students for Math Squares And Square Roots Solutions come handy for quickly completing your homework and preparing for exams.
The values whose square-roots are required. out: ndarray, None, or tuple of ndarray and None, optional. A location into which the result is stored. If provided, it must have a shape that the inputs broadcast to. If not provided or None, a freshly-allocated array is returned. A tuple (possible only as a keyword argument) must have length equal Chapter 6 Exercise 22, Introduction to Java Programming, Tenth Edition Y. Daniel LiangY. **6.22 (Math: approximate the square root) There are several techniques …
Finding Square Roots without a Calculator, a selection of answers from the Dr. Math archives. Square Roots Without a Calculator - Dr. Math FAQ How do you find the square root of a number by hand? What about cube roots? Square roots by hand: Divide and Average How do you calculate square roots by hand? Longhand Square Roots How do you find the square root of any number? Is there an easy formula Return Values. The square root of arg or the special value NAN for negative numbers.
Square Root Solutions - A Unit of Smart Stats Limited Kiltown, Castlecomer, County Kilkenny Vat Registered number: 3530538JH 07/10/2012В В· find x of the following equation : \\frac{\\sqrt{3-3x}+\\sqrt{x+6}}{\\sqrt{1-4x}+\\sqrt{2x+8}} = \\frac{\\sqrt{3-3x}-\\sqrt{x+6}}{\\sqrt{1-4x}-\\sqrt{2x+8}} Ans:x= - 2
### Square root Wikipedia
Square Roots Tutoring Solution Videos & Lessons Study.com. 08/12/2014 · To know more about Exponents, please visit https://DontMemorise.com . Don’t Memorise brings learning to life through its captivating FREE educational videos. New videos every week. To stay, Square Root 123https Www Sas Com En Us Solutions Ai Html.pdf - search pdf books free download Free eBook and manual for Business, Education,Finance, Inspirational, Novel, Religion, Social, Sports, Science, Technology, Holiday, Medical,Daily new PDF ebooks documents ready for download, All PDF documents are Free,The biggest database for Free books and documents search with fast results better.
### Square root formula in maths How to get square root of a
How do we Find the Square Root of a Number using the Long. 05/11/2014 · Negative solutions to square roots? Questions about the world of GMAT Math from other sources and general math related questions. Post a reply. 19 postsPage 1 of 2 1, 2. tgilham Course Students Posts: 4 Joined: Sun Dec 04, 2011 12:53 am . Negative solutions to square roots? by tgilham Sun Jan 22, 2012 10:41 am. I'm confused by the apparently conflicting rules on GMAT regarding this … https://en.wikipedia.org/wiki/Conductivity_(electrolytic) What is the solution for square root of 27? Unanswered Questions. Why high rainfall areas face water shortage? What are the drawbacks of Newland's law of octaves? What areas of Miami are.
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If we want to calculate square root, we can use Math.sqrt() method. It is simple. Now do you know how to write such a method by yourself? Here is the equation you need. The first sqrt number should be the input number / 2. Using the equation, we can come up with a Java Square Root method by ourselves. Mathematics Solutions Solutions for Class 6 Math Chapter 9 Square And Square Roots are provided here with simple step-by-step explanations. These solutions for Square And Square Roots are extremely popular among Class 6 students for Math Square And Square Roots Solutions come handy for quickly completing your homework and preparing for exams.
Square Root Solutions is a veteran mobile app development company, which provides comprehensive mobile app development services in Ireland for a number of domains. It is crystal clear that with the immense demand of mobile apps, businesses are seeking out for effective and efficient mobile app development partner companies to aid them in the development process. Represented by a radical symbol $\sqrt{}$ “ Square Root” is often used to refer to the principal square root. For example, 4 and -4 are the square roots of 16 because 4 2 is 16. $\LARGE \sqrt[n]{x}=x^{\frac{1}{n}}$ In order to calculate the square root, we first need to find the factors of a given number, then group the common factor
Mathematics Solutions Solutions for Class 6 Math Chapter 9 Square And Square Roots are provided here with simple step-by-step explanations. These solutions for Square And Square Roots are extremely popular among Class 6 students for Math Square And Square Roots Solutions come handy for quickly completing your homework and preparing for exams. Although the principal square root of a positive number is only one of its two square roots, the designation "the square root" is often used to refer to the principal square root. For positive x, the principal square root can also be written in exponent notation, as x 1/2.
C++ program to find Square Root of a Number. For calculate Square Root of a number we multiply number by 0.5 because square root of any number means power of 1/2 and 1/2=0.5. And one another method for this program is use sqrt() function it is pre-defined in math.h header file. Square Root Solutions - A Unit of Smart Stats Limited Kiltown, Castlecomer, County Kilkenny Vat Registered number: 3530538JH
Function: real_fft (x) Computes the fast Fourier transform of a real-valued sequence x.This is equivalent to performing fft(x), except that only the first N/2+1 results are returned, where N is the length of x.N must be power of two.. No check is made that x contains only real values.. The symmetry properites of the Fourier transform of real sequences to reduce he complexity. 05/02/2020В В· How to Calculate a Square Root by Hand. In the days before calculators, students and professors alike had to calculate square roots by hand. Several different methods have evolved for tackling this daunting process, some giving a rough...
Excel's powerful mathematical toolkit includes functions for square roots, cube roots, and even nth roots. Our review of these techniques will focus on the manual entry of formulas, but check out our tutorial on using Excel if you need a refresher on formula entry for core functions. Represented by a radical symbol $\sqrt{}$ “ Square Root” is often used to refer to the principal square root. For example, 4 and -4 are the square roots of 16 because 4 2 is 16. $\LARGE \sqrt[n]{x}=x^{\frac{1}{n}}$ In order to calculate the square root, we first need to find the factors of a given number, then group the common factor
02/02/2020 · How to Find a Square Root Without a Calculator. Calculating square root is easy if you have a perfect square. If you don't, there's a logical process you can follow to systematically figure out the square root of any number, even if you... Square roots by hand — a totally unnecessary, but awesome thing to know! Personally, I love using diagrams. I know that if sometime down the road someone asks me to calculate a square root, I
08/05/2017В В· When we find solution set of an equation inside a square root why we should assume that inside of square root should be equal to or greater than zero? For example ##\\sqrt{5x-4}##. How can I use here equal to or greater than zero symbol? Thank you. 05/02/2020В В· How to Calculate a Square Root by Hand. In the days before calculators, students and professors alike had to calculate square roots by hand. Several different methods have evolved for tackling this daunting process, some giving a rough...
B = sqrt(X) returns the square root of each element of the array X. For the elements of X that are negative or complex, sqrt(X) produces complex results. The sqrt function’s domain includes negative and complex numbers, which can lead to unexpected results if used unintentionally. Learn How to Simplify Square Roots. Reducing radicals, or imperfect square roots, can be an intimidating prospect. It’s really fairly simple, though – all you need is a basic knowledge of multiplication and factoring.Here’s how to simplify a radical in six easy steps.
## Solving square-root equations (article) Khan Academy
How to Use Math Root Rules dummies. 28/08/2015 · How to find square root of a number in Bengali 5 সেকেন্ড বর্গমূল নির্ণয় Square Root Trick - Duration: 4:53. Wonder Maths 519,547 views 4:53, To find a square root, you simply need to find a number which, raised to the power of 2 (although just multiplying by itself is a lot easier programmatically ;) ) gives back the input. So, start with a guess. If the product is too small, guess larger. If the new product is too large, you've narrowed it down - guess somewhere in between. You see.
### Contact Square Root Solutions
How to manually find a square root John Kerl. Solving square-root equations: one solution Our mission is to provide a free, world-class education to anyone, anywhere. Khan Academy is a 501(c)(3) nonprofit organization., I have always used a calculator for determining roots But I think it would be useful to know how to do this on paper. Are there different procedures for calculating square roots than for cubic roots or does it all use the same principles? So my question is how does one calculate the root ….
08/05/2017В В· When we find solution set of an equation inside a square root why we should assume that inside of square root should be equal to or greater than zero? For example ##\\sqrt{5x-4}##. How can I use here equal to or greater than zero symbol? Thank you. Excel's powerful mathematical toolkit includes functions for square roots, cube roots, and even nth roots. Our review of these techniques will focus on the manual entry of formulas, but check out our tutorial on using Excel if you need a refresher on formula entry for core functions.
Square Root 123https Www Sas Com En Us Solutions Ai Html.pdf - search pdf books free download Free eBook and manual for Business, Education,Finance, Inspirational, Novel, Religion, Social, Sports, Science, Technology, Holiday, Medical,Daily new PDF ebooks documents ready for download, All PDF documents are Free,The biggest database for Free books and documents search with fast results better Return Values. The square root of arg or the special value NAN for negative numbers.
Function: real_fft (x) Computes the fast Fourier transform of a real-valued sequence x.This is equivalent to performing fft(x), except that only the first N/2+1 results are returned, where N is the length of x.N must be power of two.. No check is made that x contains only real values.. The symmetry properites of the Fourier transform of real sequences to reduce he complexity. You are here: Home в†’ Articles в†’ Square Root Algorithm How to calculate a square root without a calculator and should your child learn how to do it. Most people in today's world feel that since calculators can find square roots, that children don't need to learn how to find square roots using any pencil-and-paper method.
I have always used a calculator for determining roots But I think it would be useful to know how to do this on paper. Are there different procedures for calculating square roots than for cubic roots or does it all use the same principles? So my question is how does one calculate the root … What is the solution for square root of 27? Unanswered Questions. Why high rainfall areas face water shortage? What are the drawbacks of Newland's law of octaves? What areas of Miami are
Square roots by hand — a totally unnecessary, but awesome thing to know! Personally, I love using diagrams. I know that if sometime down the road someone asks me to calculate a square root, I This might be a little late to answer but most simple and accurate way to compute square root is newton's method. You have a number which you want to compute its square root (num) and you have a guess of its square root (estimate).Estimate can be any number bigger than 0, but a number that makes sense shortens the recursive call depth significantly.
The values whose square-roots are required. out: ndarray, None, or tuple of ndarray and None, optional. A location into which the result is stored. If provided, it must have a shape that the inputs broadcast to. If not provided or None, a freshly-allocated array is returned. A tuple (possible only as a keyword argument) must have length equal 07/10/2012В В· find x of the following equation : \\frac{\\sqrt{3-3x}+\\sqrt{x+6}}{\\sqrt{1-4x}+\\sqrt{2x+8}} = \\frac{\\sqrt{3-3x}-\\sqrt{x+6}}{\\sqrt{1-4x}-\\sqrt{2x+8}} Ans:x= - 2
The values whose square-roots are required. out: ndarray, None, or tuple of ndarray and None, optional. A location into which the result is stored. If provided, it must have a shape that the inputs broadcast to. If not provided or None, a freshly-allocated array is returned. A tuple (possible only as a keyword argument) must have length equal Solve Equations With Square Root (√) Tutorial on how to solve equations containing square roots.Detailed solutions to examples, explanations and exercises are included. The main idea behind solving equations containing square roots is to raise to power 2 in order to clear the square root …
02/02/2020 · How to Find a Square Root Without a Calculator. Calculating square root is easy if you have a perfect square. If you don't, there's a logical process you can follow to systematically figure out the square root of any number, even if you... Chapter 6 Exercise 22, Introduction to Java Programming, Tenth Edition Y. Daniel LiangY. **6.22 (Math: approximate the square root) There are several techniques …
The Square Roots chapter of this SAT Mathematics Level 2 Tutoring Solution is a flexible and affordable path to learning about square roots. These simple and fun video lessons are each about five The values whose square-roots are required. out: ndarray, None, or tuple of ndarray and None, optional. A location into which the result is stored. If provided, it must have a shape that the inputs broadcast to. If not provided or None, a freshly-allocated array is returned. A tuple (possible only as a keyword argument) must have length equal
08/05/2017В В· When we find solution set of an equation inside a square root why we should assume that inside of square root should be equal to or greater than zero? For example ##\\sqrt{5x-4}##. How can I use here equal to or greater than zero symbol? Thank you. This might be a little late to answer but most simple and accurate way to compute square root is newton's method. You have a number which you want to compute its square root (num) and you have a guess of its square root (estimate).Estimate can be any number bigger than 0, but a number that makes sense shortens the recursive call depth significantly.
B = sqrt(X) returns the square root of each element of the array X. For the elements of X that are negative or complex, sqrt(X) produces complex results. The sqrt function’s domain includes negative and complex numbers, which can lead to unexpected results if used unintentionally. 08/05/2017 · When we find solution set of an equation inside a square root why we should assume that inside of square root should be equal to or greater than zero? For example ##\\sqrt{5x-4}##. How can I use here equal to or greater than zero symbol? Thank you.
Sal solves the equation в€љ(3x-7)+в€љ(2x-1)=0, only to find out that the single solution is extraneous, which means the equation has no solution. If you're seeing this message, it means we're having trouble loading external resources on our website. Square Root Solutions is a veteran mobile app development company, which provides comprehensive mobile app development services in Ireland for a number of domains. It is crystal clear that with the immense demand of mobile apps, businesses are seeking out for effective and efficient mobile app development partner companies to aid them in the development process.
C++ program to find Square Root of a Number. For calculate Square Root of a number we multiply number by 0.5 because square root of any number means power of 1/2 and 1/2=0.5. And one another method for this program is use sqrt() function it is pre-defined in math.h header file. The Square Roots chapter of this SAT Mathematics Level 2 Tutoring Solution is a flexible and affordable path to learning about square roots. These simple and fun video lessons are each about five
If we want to calculate square root, we can use Math.sqrt() method. It is simple. Now do you know how to write such a method by yourself? Here is the equation you need. The first sqrt number should be the input number / 2. Using the equation, we can come up with a Java Square Root method by ourselves. numpy.roots¶ numpy.roots (p) [source] ¶ Return the roots of a polynomial with coefficients given in p. The values in the rank-1 array p are coefficients of a polynomial. If the length of p is n+1 then the polynomial is described by:
home / study / math / algebra / algebra solutions manuals / Prealgebra / 2nd edition / chapter 8.6 / problem 32PE. Prealgebra (2nd Edition) Edit edition. Problem 32PE from Chapter 8.6: For Exercise, simplify the squares and square roots. (See Ex... Get solutions . Looking for the textbook? We have solutions for your book! Chapter: 07/10/2012В В· find x of the following equation : \\frac{\\sqrt{3-3x}+\\sqrt{x+6}}{\\sqrt{1-4x}+\\sqrt{2x+8}} = \\frac{\\sqrt{3-3x}-\\sqrt{x+6}}{\\sqrt{1-4x}-\\sqrt{2x+8}} Ans:x= - 2
Although the principal square root of a positive number is only one of its two square roots, the designation "the square root" is often used to refer to the principal square root. For positive x, the principal square root can also be written in exponent notation, as x 1/2. We're much closer. The square of 297.543 is 88531.84. As we did above, we could continue and add a few more pairs of zeros onto the number to obtain a more exact answer (a more exact answer is 297.54398). Return to Top. WHY DOES THIS METHOD WORK? Our method is derived from algebra. Let's find the square root of an algebraic expression.
The values whose square-roots are required. out: ndarray, None, or tuple of ndarray and None, optional. A location into which the result is stored. If provided, it must have a shape that the inputs broadcast to. If not provided or None, a freshly-allocated array is returned. A tuple (possible only as a keyword argument) must have length equal Sal solves the equation в€љ(3x-7)+в€љ(2x-1)=0, only to find out that the single solution is extraneous, which means the equation has no solution. If you're seeing this message, it means we're having trouble loading external resources on our website.
### Mathematics Solutions for Class 6 Math Chapter 9 Square
How to Compute a Manual Square Root The Rth Dimension. Square Root Solutions is a veteran mobile app development company, which provides comprehensive mobile app development services in Ireland for a number of domains. It is crystal clear that with the immense demand of mobile apps, businesses are seeking out for effective and efficient mobile app development partner companies to aid them in the development process., 05/02/2020В В· How to Calculate a Square Root by Hand. In the days before calculators, students and professors alike had to calculate square roots by hand. Several different methods have evolved for tackling this daunting process, some giving a rough....
Calculate Square Root Without Using Math.Sqrt in C#. Calculate Square Root Without Using Sqrt in C . First one, we have to know how to calculate square root without using a function. For calculate square root of a number, we will use The Babylonian Method for Computing Square Roots . Calculate Square Root without Math.Sqrt Method In C# Console (Only int type), Solve Equations With Square Root (√) Tutorial on how to solve equations containing square roots.Detailed solutions to examples, explanations and exercises are included. The main idea behind solving equations containing square roots is to raise to power 2 in order to clear the square root ….
### How to Calculate a Square Root by Hand (with Pictures
square root NIST. Methods of computing square roots are numerical analysis algorithms for finding the principal, or non-negative, square root (usually denoted в€љ S, 2 в€љ S, or S 1/2) of a real number. https://en.wikipedia.org/wiki/Conductivity_(electrolytic) The Square Roots chapter of this SAT Mathematics Level 2 Tutoring Solution is a flexible and affordable path to learning about square roots. These simple and fun video lessons are each about five.
Although the principal square root of a positive number is only one of its two square roots, the designation "the square root" is often used to refer to the principal square root. For positive x, the principal square root can also be written in exponent notation, as x 1/2. Learn How to Simplify Square Roots. Reducing radicals, or imperfect square roots, can be an intimidating prospect. It’s really fairly simple, though – all you need is a basic knowledge of multiplication and factoring.Here’s how to simplify a radical in six easy steps.
Learn How to Simplify Square Roots. Reducing radicals, or imperfect square roots, can be an intimidating prospect. It’s really fairly simple, though – all you need is a basic knowledge of multiplication and factoring.Here’s how to simplify a radical in six easy steps. Finding Square Roots without a Calculator, a selection of answers from the Dr. Math archives. Square Roots Without a Calculator - Dr. Math FAQ How do you find the square root of a number by hand? What about cube roots? Square roots by hand: Divide and Average How do you calculate square roots by hand? Longhand Square Roots How do you find the square root of any number? Is there an easy formula
Represented by a radical symbol $\sqrt{}$ “ Square Root” is often used to refer to the principal square root. For example, 4 and -4 are the square roots of 16 because 4 2 is 16. $\LARGE \sqrt[n]{x}=x^{\frac{1}{n}}$ In order to calculate the square root, we first need to find the factors of a given number, then group the common factor The Square Roots chapter of this SAT Mathematics Level 2 Tutoring Solution is a flexible and affordable path to learning about square roots. These simple and fun video lessons are each about five
Finding Square Roots without a Calculator, a selection of answers from the Dr. Math archives. Square Roots Without a Calculator - Dr. Math FAQ How do you find the square root of a number by hand? What about cube roots? Square roots by hand: Divide and Average How do you calculate square roots by hand? Longhand Square Roots How do you find the square root of any number? Is there an easy formula Calculate Square Root Without Using Sqrt in C . First one, we have to know how to calculate square root without using a function. For calculate square root of a number, we will use The Babylonian Method for Computing Square Roots . Calculate Square Root without Math.Sqrt Method In C# Console (Only int type)
I have always used a calculator for determining roots But I think it would be useful to know how to do this on paper. Are there different procedures for calculating square roots than for cubic roots or does it all use the same principles? So my question is how does one calculate the root … To find a square root, you simply need to find a number which, raised to the power of 2 (although just multiplying by itself is a lot easier programmatically ;) ) gives back the input. So, start with a guess. If the product is too small, guess larger. If the new product is too large, you've narrowed it down - guess somewhere in between. You see
Sal solves the equation √(3x-7)+√(2x-1)=0, only to find out that the single solution is extraneous, which means the equation has no solution. If you're seeing this message, it means we're having trouble loading external resources on our website. Learn How to Simplify Square Roots. Reducing radicals, or imperfect square roots, can be an intimidating prospect. It’s really fairly simple, though – all you need is a basic knowledge of multiplication and factoring.Here’s how to simplify a radical in six easy steps.
The values whose square-roots are required. out: ndarray, None, or tuple of ndarray and None, optional. A location into which the result is stored. If provided, it must have a shape that the inputs broadcast to. If not provided or None, a freshly-allocated array is returned. A tuple (possible only as a keyword argument) must have length equal The Square Roots chapter of this SAT Mathematics Level 2 Tutoring Solution is a flexible and affordable path to learning about square roots. These simple and fun video lessons are each about five
Return Values. The square root of arg or the special value NAN for negative numbers. 05/02/2020В В· How to Calculate a Square Root by Hand. In the days before calculators, students and professors alike had to calculate square roots by hand. Several different methods have evolved for tackling this daunting process, some giving a rough...
Return Values. The square root of arg or the special value NAN for negative numbers. This might be a little late to answer but most simple and accurate way to compute square root is newton's method. You have a number which you want to compute its square root (num) and you have a guess of its square root (estimate).Estimate can be any number bigger than 0, but a number that makes sense shortens the recursive call depth significantly.
View all posts in Earl Grey category
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2022-05-24 20:50:54
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https://socratic.org/questions/583bddb511ef6b13ba078d7e
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# Given the combustion of silane... SiH_4(g)+2O_2(g)rarrSiO2(s)+2H_2O(g); DeltaH=−1429⋅kJ⋅mol^(−1).. How much heat will evolve given combustion of 15.7*g quantity?
Nov 28, 2016
Approx. $700 \cdot k J$
#### Explanation:
Thermochemical reactions ALWAYS quote enthalpy input/output PER MOLE OF REACTION AS WRITTEN:
$S i {H}_{4} \left(g\right) + 2 {O}_{2} \left(g\right) \rightarrow S i {O}_{2} \left(s\right) + 2 {H}_{2} O \left(g\right)$ $\Delta H = - 1429 \cdot k J \cdot m o {l}^{-} 1$.
That is $- 1429 \cdot k J \cdot m o {l}^{-} 1$ of energy are involved when $1 \cdot m o l$, $33 \cdot g$ of silane are combusted to give stoichiometric silicon oxide, and water.
And thus we simply work out the molar quantity of silane:
$\frac{15.7 \cdot g}{32.12 \cdot g \cdot m o {l}^{-} 1} = 0.489 \cdot m o l$
And $0.489 \cdot m o l \left(\text{of silane")xx-1429*kJ*mol^-1("of silane}\right)$ $=$ ??kJ.
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2019-09-18 11:56:00
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http://blog.mcchan.io/bridge-remote-networks-using-vxlan
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In this article, we would like to bridge two remote Mininet environments using VXLAN.
## Environment
The following figure shows the network topology:
The network of left-hand-side is simunated on 140.113.215.191 The network of right-hand-side is simunated on 140.113.215.200
## Honest Advice
Check your OVS version by ovs-vsctl show and make sure you are working with version > 2.0.1 It wastes me two nights just because there is something wrong in the old version…
## Advanced Configuration
#### Manually assign VXLAN Network ID (VNI) and/or OpenFlow port number
e.g. VNI=5566, OF_PORT=9
#### Assign VNI flow by flow
(Useful when implementing multi-tenant environment)
and then setup your flow entries by
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2017-10-16 21:57:11
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http://tex.stackexchange.com/questions/70436/enclose-an-entry-in-an-enumerate-list-in-parentheses
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Enclose an entry in an enumerate list in parentheses
I'd like to enclose one entry of an enumerate list in parentheses, with the opening parenthesis appearing before the index number. I can do this manually by using \item[(3.] Item text), but this requires hard-coding the item number. Is there a way to do this automatically?
\documentclass{article}
\begin{document}
\begin{enumerate}
\item Really important
\item Quite important
\item[(3.] If we have time)
\end{enumerate}
\end{document}
In the answer to Modifying labels on some enumerated items, an approach is suggested for modifying the item label, which gets me quite close to the goal. The opening parenthesis is added and the counter is still automatic. I only need to add the closing parenthesis by hand. Could that be automated as well?
\documentclass{article}
\begin{document}
\newcommand{\parenitem}{\stepcounter{enumi}\item[(\theenumi.]}
\begin{enumerate}
\item Really important
\item Quite important
\parenitem If we have time)
\end{enumerate}
\end{document}
-
You may look at this question. – egreg Sep 6 '12 at 14:58
This is where ConTeXt's \startitem ... \stopitem approach is better (it's only optional in ConTeXt, but is required for some mechanisms to work). – mbork Sep 15 '12 at 11:52
Related, yet unanswered question with respect to the "do not want to mark the end of item by hand" aspect. – Daniel Sep 20 '12 at 6:55
Another attempt, counting the open parentheses.
\documentclass{article}
\usepackage{etoolbox}
\makeatletter
\newcounter{item@paren@depth}
\newcommand{\insert@item@paren}{%
\ifnum\value{item@paren@depth}>0
\fi%
}
\newcommand{\pitem}{%
\@noitemargtrue \item[\llap{(}\@itemlabel ]%
\stepcounter{item@paren@depth}%
}
\pretocmd{\endenumerate}{\insert@item@paren}{\relax}{\relax}
\pretocmd{\item}{\insert@item@paren}{\relax}{\relax}
\makeatother
\begin{document}
\begin{enumerate}
\item Really important
\item Quite important
\pitem If we have time
\item Whatever it takes
\begin{enumerate}
\pitem maybe
\item definitely
\end{enumerate}
\pitem first
\pitem second
\pitem third
\end{enumerate}
\end{document}
The result is the following
As shown in the example, empty lines still cause a deserted parenthesis. Right now I have no idea how to fix this.
EDIT (2012-09-16)
Just had time to look into the TeXbook: the end-of-line character \endlinechar can be set to a negative value to ignore empty lines (or actually line breaks). If one includes this in the \pitem macro, the lonesome paren artefact is fixed:
\newcommand{\pitem}{%
\@noitemargtrue \item[\llap{(}\@itemlabel ]%
\stepcounter{item@paren@depth}%
\ifnum\endlinechar>0\endlinechar=-1\fi
}
The behavior will only be activated when the \pitem macro is used and the effect will be limited to the scope of the enumerate environment. Note that explicit line breaks using \newline or \\ ans explicit paragraphs with \par still work.
-
\documentclass{article}
\def\Item(#1){\item[\llap{(}\refstepcounter{enumi}\theenumi.] #1)}
\begin{document}
\begin{enumerate}
\item Really important
\item Quite important
\Item (If we have time)
\end{enumerate}
\end{document}
-
Ah yes, very nice, thank you! I guess it would be quite hard to do this in a way that doesn't require delimiters for the item text? – Jake Sep 6 '12 at 15:09
yes, that is not really easy. However, you can use \def\Item#1) and use only one ) – Herbert Sep 6 '12 at 15:45
@Herbert A very simple and elegant solution. – Sveinung Sep 20 '12 at 6:37
Since there is no \tikz answer I thought I felt obligated to provide one:
1. To keep my reputation for the overkill solution. :-)
2. But seriously, I interpreted that the goal of this question was to draw attention to a particular item in a list.
Adding a parenthesis is not the only way to highlight an \item in a list, and by using the infamous \tikzmark many other options are possible. Below I have used the term marker to refer to the the elements that are used to draw attention to a list member.
Basic:
To use the technique defined here, all you need to do is to use \SpecialItem instead of the usual \item in the list. This will by default make a call to \DrawParen which adds a parenthesis at the start and end of the list item as shown here:
\begin{enumerate}
\SpecialItem Default behaviour of \verb|\SpecialItem.|
\SpecialItem \verb|\SpecialItem| with longer text:
Lorem ipsum dolor sit amet, consectetur adipiscing elit
\end{enumerate}
As requested by Jake, there is no need to specify where the end parenthesis is placed. This is determined automatically based on where the text of the \item terminates. So, the code above generates (with the preamble used in the MWE below):
There is a question as to what to do when the text takes up more than one line, as in the second case above. To handle this case, I have defined a starred variant, \DrawParen* which takes into account the height of the lines of text and the parenthesis are re-sized appropriately:
To facilitate the use of different drawing macros, \SpecialItem accepts an optional first parameter to specify the macro that is to be used to do the actual drawing. This defaults to \DrawParen, so to use the starred variant we need to use \SpecialItem[\DrawParen*]. So, the code:
\begin{enumerate}
\SpecialItem[\DrawParen*] \verb|\SpecialItem[\DrawParen*]| with longer text:
Lorem ipsum dolor sit amet, consectetur adipiscing elit
\end{enumerate}
yields:
Now the parenthesis are high enough to enclose the multiple lines and the right one is placed on the right side.
Extended:
The above was the basic usage, but you can define your own drawing macros. Below, I have defined several drawing macros.
1. \SpecialItem[\DrawAsterix]:
Since there is no marker on the right hand side, \DrawAsterix and \DrawAsterix* are identical.
2. \SpecialItem[\DrawBrace]:
3. \SpecialItem[\DrawBracket]:
Similar to \DrawBrace, but draws a square bracket.
4. \SpecialItem[\DrawBox]:
Note that it does not make sense to use \DrawBox (the un-starred variant) when the text requires multiple lines.
5. \SpecialItem[\DrawShadedBox]:
Custom Markers:
If the drawing options defined here are not enough, you can define your own and pass this macro to \SpecialItem. Any custom drawing macro would need to be defined with arg specs {s O{} m m}, where I have used the format from the xparse package. The parameters to this custom drawing macro are:
* starred variant sets the markers at the end of the line on the right
#2 = optional drawing parameter.
This is actually not used in the code as of yet, at least not fully
used for its intended purpose.
#3 = name of \tikzmark that defines the location of the start of this \item,
#4 = name of \tikzmark that defines the location of the end of this \item.
So, assuming you want to stick with the xparse package, then \MyCustomDrawMacro would look like:
\NewDocumentCommand{\MyCustomDrawMacro}{s O{} m m}{%
\begin{tikzpicture}[overlay, remember picture]
\IfBooleanTF{#1}{%
... draw for starred variant ...
}{%
... draw for un-starred variant ...
}%
\end{tikzpicture}%
}%
Then to use this you would provide this as the first optional parameter to \SpecialItem:
\SpecialItem[\MyCustomDrawMacro] ...text of item here...
Nested Usage:
Although not all combinations produce good results, it is now possible to have nested usage:
and even further nesting:
It should be noted that for nested usage there needs to be indenting on the right hand side so that the markers don't all overlap. To achieve this I used the enumitem package:
\setlist{before=\setlength{\rightmargin}{\leftmargin}}
Notes:
• This does require two runs: the first to compute the positions of the drawing, and the second to draw it in the correct spot.
• Since this is using tikz, you automatically get all the flexibility inherent in tikz, such as line styles, line thickness, line color, fill, etc.
• Even though I used the the xparse package, this could certainly be done without this additional package if so desired.
• I have used newtoggle from the etoolbox package as I prefer that syntax versus the \newif syntax. But if you don't want to include an additional package it should be pretty straightforward to adapt this to use \newif or some other conditional methods.
• It should be noted that in this answer to strange interaction between mdframed and item, egreg mentions that
Redefining \item can be dangerous and have impredictable results
which is exactly what I have done here, so perhaps an alternate solution might be needed if this fails under certain circumstances.
Known Issues:
• Although the nested usage works as shown there is something that is nto getting properly reset after nested usage that affects the non-nested usage. In the MWE below I have commented out the test cases for the nested usage so that it produces useable results. However, if you un-comment the nested usage test cases you will notice that the subsequent usage is really messed up. Will look into this and try to post an update
Further Enhancements:
• The use of \DrawBox without the * does not make sense for the case where the text is longer than one line. One could automate a test for this and automatically revert to \DrawBox* if the content was longer than one line. This should not be too difficult.
• The drawing for \DrawParen using bend left can result in a large bracket if the text is over many lines. Perhaps some logic here to limit the amount of bending to some maximum?
• There is a slight issue when you try to fill the text with a color in that the text is not placed via \tikz so that a low fill opacity needs to be used. To fix this issue, perhaps get \tikz to place the text and hence one could specify text opacity=1.0 so that a darker fill could be used.
• The left brace is currently to the right of the margin, and the right brace (with the * variant is past the right margin. So perhaps some tweaking here is needed if that is a problem. Need to decide if both the drawing should just be on the margin, of if you want the drawing within the margin, then need to reduce the line width to which the text can flow.
• Tweaks needed for placement of the markers in nested usage.
• The current version requires that a new \Draw... macro be defined if you want to change any of the tikz settings. For instance \DrawShadedBox is really the same as \DrawBox[Shaded Box Style]..., but I do not know of a way to pass in optional parameters along with the macro name (but without passing the mandatory parameters as they are only known later).
Caveat:
This section can safely be ignored, and is ONLY relevant in case one tries to compare this to the earlier solution at Box around a few items in an itemize environment. Otherwise, please ignore this section as it will only result in confusion -- it certainly confused me and I wrote the other solution!!
Ok, since you are choosing to read on: The earlier solution accommodated boxing the content with either the label included or not included. In the earlier solution, there is \DrawBox, which does not include the label and \DrawBoxWide which does include the label in the box. In this solution I have decided to not provide the case where the label is not boxed. So, what this all means is that \DrawBox in this earlier solution does not have a corresponding macro here, and that the \DrawBoxWide from the earlier solution corresponds to \DrawBox in this solution.
If this section does not make sense, please ignore it -- it will help me in the future should I need to come back and make sense of these two solutions.
Code:
\documentclass{article}
\usepackage{etoolbox}% \newtoggle (conditional processing)
\usepackage{letltxmacro}% Duplicate definitions of existing macros
\usepackage{xparse}% \NewDocumentCommand and \RenewDocumentCommand
\usepackage{xstring}% \IfEq
\usepackage{enumitem}%
\usepackage{tikz}%
\usetikzlibrary{calc}
\usetikzlibrary{decorations.pathreplacing}
%\usepackage{showframe}%
\newcommand{\Text}{% Dummy text for testing purposes
Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Sed accumsan nulla ac ipsum elementum interdum.
}%
\newcommand{\tikzmark}[1]{\tikz[overlay,remember picture] \node (#1) {};}
% -------------------------------------------------- Drawing Settings
\newcommand*{\RightTweak}{0.2em,-0.3em}%
\newcommand*{\LeftTweak}{-\labelwidth,0.9em}%
\newcommand*{\BraceAmplitude}{0.25em}%
% -------------------------------------------------- Drawing Macros
\tikzset{Box Style/.style={draw=red}}%
\NewDocumentCommand{\DrawBox}{%
s % * = box drawn to full line width
O{}% #2 = optional tikz draw/fill paramaters
m % #3 = name of left \tikzmark
m % #4 = name of right \tikzmark
}{%
%
\tikz[overlay,remember picture]{%
\IfBooleanTF{#1}{%
\coordinate (SWPoint) at ($(#3 |- #4)+(\linewidth,0)$);
}{%
\coordinate (SWPoint) at (#4);
}%
\draw[Box Style, #2] ($(#3)+(\LeftTweak)$) rectangle ($(SWPoint)+(\RightTweak)$);}
}%
\tikzset{Shaded Box Style/.style={thick, draw=violet, fill=yellow!20, fill opacity=0.1}}%
s % * = box drawn to full line width
O{}% #2 = optional tikz draw/fill paramaters
m % #3 = name of left \tikzmark
m % #4 = name of right \tikzmark
}{%
%
% Note that the fill opacity needs to be quite small as this fill
% is done on top of the text (which was not placed here via tikz.
\IfBooleanTF{#1}{%
}{%
}%
}%
% To properly place the left brace, paren, bracket, this needs tweaking
\newcommand*{\LeftTweakBrackets}{\labelwidth}%
% This is shared with the bracket/paren drawing macros
\NewDocumentCommand{\ComputeCoordinates}{%
s%
O{}% #2 = Unused here -- makes the #3, #4 compatible with macros below
m% #3 = name of left \tikzmark
m% #4 = name of right \tikzmark
}{%
\IfBooleanTF{#1}{%
\coordinate (NEPoint) at ($(#3.north)+(-\LeftTweakBrackets, 0.5*\baselineskip)$);
\coordinate (SEPoint) at ($(#3 |- #4)+(-\LeftTweakBrackets,-0.5*\baselineskip)$);
%
\coordinate (NWPoint) at ($(#3.north)+(\linewidth, 0.5*\baselineskip)$);
\coordinate (SWPoint) at ($(#3 |- #4)+(\linewidth,-0.5*\baselineskip)$);
}{%
\coordinate (NEPoint) at ($(#3.north)+(-\LeftTweakBrackets, 0.5*\baselineskip)$);
\coordinate (SEPoint) at ($(#3) +(-\LeftTweakBrackets,-0.5*\baselineskip)$);
%
\coordinate (NWPoint) at ($(#4.north)+(0, 0.5*\baselineskip)$);
\coordinate (SWPoint) at ($(#4) +(0,-0.5*\baselineskip)$);
}%
}%
\tikzset{Brace Style/.style={
decoration={brace,amplitude=\BraceAmplitude}, decorate,
ultra thick, blue
}%
}%
\NewDocumentCommand{\DrawBrace}{%
s % * = draw to full line width
O{}% #2 = optional tikz draw/fill paramaters
m % #3 = name of left \tikzmark
m % #4 = name of right \tikzmark
}{%
\begin{tikzpicture}[overlay, remember picture]
\IfBooleanTF{#1}{%
\ComputeCoordinates*{#3}{#4}%
}{%
\ComputeCoordinates{#3}{#4}%
}%
\draw [Brace Style, #2] (SEPoint) -- (NEPoint);
\draw [Brace Style, #2] (NWPoint) -- (SWPoint);
\end{tikzpicture}%
}%
% http://tex.stackexchange.com/questions/55068/is-there-a-tikz-equivalent-to-the-pstricks-ncbar-command
\tikzset{
ncbar/.style={% easy way to get sqaure brackets
to path=(\tikztostart)
-- ($(\tikztostart)!#1!90:(\tikztotarget)$)
-- ($(\tikztotarget)!#1!-90:(\tikztostart)$)
-- (\tikztotarget)
},
ncbar/.default=0.5cm
}
\tikzset{Bracket Style/.style={ultra thick, brown}}%
\NewDocumentCommand{\DrawBracket}{s O{} m m}{%
\begin{tikzpicture}[overlay, remember picture]
\IfBooleanTF{#1}{%
\ComputeCoordinates*{#3}{#4}%
}{%
\ComputeCoordinates{#3}{#4}%
}%
\draw [Bracket Style, #2] (SEPoint) to [ncbar=\BraceAmplitude] (NEPoint);
\draw [Bracket Style, #2] (NWPoint) to [ncbar=\BraceAmplitude] (SWPoint);
\end{tikzpicture}%
}%
\tikzset{Paren Style/.style={ultra thick, red}}%
\NewDocumentCommand{\DrawParen}{s O{} m m}{%
\begin{tikzpicture}[overlay, remember picture]
\IfBooleanTF{#1}{%
\ComputeCoordinates*{#3}{#4}%
}{%
\ComputeCoordinates{#3}{#4}%
}%
\draw [Paren Style, #2] (SEPoint) to [bend left] (NEPoint);
\draw [Paren Style, #2] (NWPoint) to [bend left] (SWPoint);
\end{tikzpicture}%
}%
\tikzset{Asterix Style/.style={text=red}}%
\NewDocumentCommand{\DrawAsterix}{s O{} m m}{%
\begin{tikzpicture}[overlay, remember picture]
\IfBooleanTF{#1}{%
\ComputeCoordinates*{#3}{#4}%
}{%
\ComputeCoordinates{#3}{#4}%
}%
\node [Asterix Style, #2] at ($(SEPoint)!0.5!(NEPoint)$) {\Huge$\ast$};
\end{tikzpicture}%
}%
% -------------------------------------------------- Non-Drawing Macros
% This toggle is set when we are within a "\SpecialItem" so that we
% can do the appropriate drawing when we get to the end of this item.
% To allow for nesting we need one of these for each nesting depth
% So, to allow for more levels of nesting declare more of these.
\newtoggle{InSpecialItem1}\togglefalse{InSpecialItem1}%
\newtoggle{InSpecialItem2}\togglefalse{InSpecialItem2}%
\newtoggle{InSpecialItem3}\togglefalse{InSpecialItem3}%
\newtoggle{InSpecialItem4}\togglefalse{InSpecialItem4}%
% To allow for nesting we need to use different names for the tikzmarks,
% and the toggles (defined above). So we use the vallue of this counter
% to name those. This counted is incremented at the \begin{enumerate} and
% decremented at \end{enumerate}
\newcounter{EnumerateDepth}%
\makeatletter
% http://tex.stackexchange.com/questions/20655/how-to-undo-a-def-i-e-need-a-undef-capability
\newcommand*\ResetToUndefined[1]{\expandafter\gdef\csname#1\endcsname{\@undefined}}%
\makeatother
\newcommand*{\EndTikzMarkAndDrawIfNeeded}{%
\iftoggle{InSpecialItem\arabic{EnumerateDepth}}{%
% We have reached the end of a \SpecialItem, which could be
% either due to a subsequent \item, a subsequent \SpecialItem,
% to an end{enumerate}.
\global\togglefalse{InSpecialItem\arabic{EnumerateDepth}}%
\ifcsname MarkEnd\Alph{EnumerateDepth}\endcsname%
% The location of the end \tikzmark was already marked,
% which would be the case if we were coming out of a nested
% \end{enumerate}).
%
% We need to clear this defintion so that it can be used
% again if needed:
\ResetToUndefined{MarkEnd\Alph{EnumerateDepth}}%
\else%
% The location of the end \tikzmark was not already marked
% Hence, we need to mark this current point as the end
% \tikzmark location.
\tikzmark{MarkEnd\Alph{EnumerateDepth}}%
\fi%
% -----------------------------------------------------------
% Draw whatever was specified to be drawn by \SpecialItem
% and draw whatever was specified to be drawn by \SpecialItem
\SpecialItemStyle[thick]%
{MarkStart\Alph{EnumerateDepth}}%
{MarkEnd\Alph{EnumerateDepth}}%
}{}%
}%
% To be able to handle nested use of \SpecialItem we need to know
% what enumerate depth we are at, so we increment that counter at
% every \begin{enumerate}. Hence first level has count=1.
\LetLtxMacro\OriginalEnumerate{\enumerate}%
\renewcommand*{\enumerate}{%
\OriginalEnumerate%
}%
% Special Case: If we are ending a nested enumerarte, but the last item
% in the parent list is a SpecialItem we need to close those as well.
\newcounter{NestingDepthCounter}
\newcommand*{\EndAnyParentTikzMarks}{%
\edef\NestingDepth{\arabic{EnumerateDepth}}%
\IfStrEq{\NestingDepth}{0}{}{%
\foreach \x in {1,...,\NestingDepth} {%
\setcounter{NestingDepthCounter}{\x}%
\iftoggle{InSpecialItem\arabic{NestingDepthCounter}}{%
% Note that we do NOT togglefalse{InSpecialItem\x} here as
% the drawing needs to be done we come out of this enumerate
% so that the line widths are correct, and that the correct
% drawing macro is used for that enumerated depth.
%% \global\togglefalse{InSpecialItem\x}% No!! Not for this special case!
\ifcsname MarkEnd\Alph{EnumerateDepth}\endcsname%
% The location of the end \tikzmark was already marked,
% which would be the case if we were coming out of a nested
% \end{enumerate}). So don't mark it again.
\else%
\tikzmark{MarkEnd\Alph{NestingDepthCounter}}%
%
% So that we know that we have already marked an end for this
% \tikzmark and don't overwrite the current location.
% If there is a way to check if a \tikzmark is already defined
% then this \gdef here could be elimianted.
\expandafter\gdef\csname MarkEnd\Alph{NestingDepthCounter}\endcsname{}%
\fi%
}{}%
}%
}%
}%
% If last \item was a special \tikzmark, then at the end of
% enumerate we need to add the other end of the \tikzmark,
% and do the appropriate drawing.
\let\OriginalEndEnumerate\endenumerate%
\renewcommand*{\endenumerate}{%
\EndTikzMarkAndDrawIfNeeded%
%
\EndAnyParentTikzMarks%
%
\OriginalEndEnumerate% end the enumerate
}%
% If previous \item was a special \tikzmark, then at the
% subsequent \item we need to add the other end of the
% \tikzmark, and do the appropriate drawing
\LetLtxMacro\OriginalItem{\item}%
\RenewDocumentCommand{\item}{o}{%
\EndTikzMarkAndDrawIfNeeded%
\IfNoValueTF{#1}{%
\OriginalItem% start the usual item
}{%
\OriginalItem[#1]% start the usual item with given label
}%
}%
\NewDocumentCommand{\SpecialItemStyle}{O{} m m}{}%
\NewDocumentCommand{\SpecialItem}{%
O{\DrawParen}% #1 = highlighting type
o% #2 = optional paramater to \item
}{%
\EndTikzMarkAndDrawIfNeeded% In case previous item was also a \SpecialItem
% --------------------------------------------------
% Redefine how this particular special item is to be marked when it ends.
\RenewDocumentCommand{\SpecialItemStyle}{O{} m m}{#1[##1]{##2}{##3}}%
% --------------------------------------------------
\global\toggletrue{InSpecialItem\arabic{EnumerateDepth}}%
\IfNoValueTF{#2}{%
\OriginalItem% start a special item
}{%
\OriginalItem[#2]% start a special item with given label
}%
\tikzmark{MarkStart\Alph{EnumerateDepth}}%
\ignorespaces% As per http://tex.stackexchange.com/questions/73434
}%
\setlist{before=\setlength{\rightmargin}{\leftmargin}}
\begin{document}
\begin{enumerate}
\item Normal Item
\item[A.] Normal Item with custon label [A.]
\SpecialItem \verb|\DrawParen|
\SpecialItem \verb|\DrawParen| \Text
\SpecialItem[\DrawParen*] \verb|\DrawParen*|
\SpecialItem[\DrawParen*] \verb|\DrawParen*| \Text
\SpecialItem[\DrawAsterix] \verb|\DrawAsterix|
\SpecialItem[\DrawBrace] \verb|DrawBrace|
\SpecialItem[\DrawBrace*] \verb|DrawBrace*|
\item A normal item in between special items
\SpecialItem[\DrawBrace] DrawBrace with text: \Text
\SpecialItem[\DrawBrace*] DrawBrace* with text: \Text
\SpecialItem[\DrawBracket] DrawBracket with text: \Text
\SpecialItem[\DrawBracket*] DrawBracket* with text: \Text
\SpecialItem[\DrawBox] DrawBox Item
\SpecialItem[\DrawBox*] DrawBox*
\SpecialItem[\DrawBox] DrawBox with text - Does not make sense.
\SpecialItem[\DrawBox*] DrawBox with text: \Text
\end{enumerate}
%\newpage
%Check nesting:
%\begin{enumerate}
% \SpecialItem[\DrawBrace] \verb|\DrawBrace| of parent with nested list
% \begin{enumerate}
% \SpecialItem[\DrawBracket] \verb|\DrawBracket| nested in above list
% \end{enumerate}
% %
% \SpecialItem[\DrawBrace*] \verb|\DrawBrace*| of parent with nested list: \Text
% \begin{enumerate}
% \SpecialItem[\DrawBracket*] \verb|\DrawBracket*| nested in above list: \Text
% \end{enumerate}
% %
% \SpecialItem[\DrawBracket*] \verb|\DrawBracket*| of parent with nested list
% \begin{enumerate}
% \SpecialItem[\DrawBrace*] \verb|\DrawBrace*| nested in above list
% \begin{enumerate}
% \SpecialItem[\DrawBox*] \verb|\DrawBox*| nested in above list
% \begin{enumerate}
% \SpecialItem[\DrawParen] \verb|\DrawParen| nested in above list \Text
% \item Regular item
% \end{enumerate}
% \end{enumerate}
% \end{enumerate}
%\end{enumerate}
\newpage
Test cases given in description:
\begin{enumerate}
\SpecialItem Default behaviour of \verb|\SpecialItem.|
\SpecialItem \verb|\SpecialItem| with longer text:
Lorem ipsum dolor sit amet, consectetur adipiscing elit
\end{enumerate}
\begin{enumerate}
\SpecialItem[\DrawParen*] \verb|\SpecialItem[\DrawParen*]| with longer text:
Lorem ipsum dolor sit amet, consectetur adipiscing elit
\end{enumerate}
\begin{enumerate}
\SpecialItem[\DrawAsterix] \verb|\SpecialItem[\DrawAsterix]| with longer text:
Lorem ipsum dolor sit amet, consectetur adipiscing elit
\end{enumerate}
\begin{enumerate}
\SpecialItem[\DrawBrace] \verb|\SpecialItem[\DrawBrace]| with short text.
\SpecialItem[\DrawBrace] \verb|\SpecialItem[\DrawBrace]| with longer text:
Lorem ipsum dolor sit amet, consectetur adipiscing elit
\SpecialItem[\DrawBrace*] \verb|\SpecialItem[\DrawBrace*]| with longer text:
Lorem ipsum dolor sit amet, consectetur adipiscing elit
\end{enumerate}
\begin{enumerate}
\SpecialItem[\DrawBox] \verb|\SpecialItem[\DrawBox]| with short text.
\SpecialItem[\DrawBox*] \verb|\SpecialItem[\DrawBox*]| with longer text:
Lorem ipsum dolor sit amet, consectetur adipiscing elit
\end{enumerate}
\begin{enumerate}
Lorem ipsum dolor sit amet, consectetur adipiscing elit
\end{enumerate}
\end{document}
-
+1 for overkill :-) – Daniel Sep 20 '12 at 5:17
I would love to use this with beamer, but looking at the redefinitions of item and the list environments, I have a feeling that it would not work. (Can't check at the moment – no LaTeX for the iPad...) – Daniel Sep 20 '12 at 5:21
@Daniel: Probably requires someone more knowledgeable than me to redefine those macros properly. Alternatively, could define a new macro Item and use that instead of \item, similar to what @Herbert did. – Peter Grill Sep 20 '12 at 5:52
Now this goes into CTAN, right? – percusse Sep 20 '12 at 6:40
@percusse: Yep, it's \usepackage{overkill}. :-) – Peter Grill Sep 20 '12 at 7:01
Here is an attempt. The following code defines a \pitem that encloses everything until the next occurence of \item, \pitem or \end (whatever comes first) with parentheses. It uses egreg's definition of \sitem in his answer to “Modifying labels on some enumerated items”.
\documentclass{article}
\makeatletter
\long\def\ifinstring#1#2#3#4{%
\long\def\instr@tmpa##1#2{}%
\expandafter\if\expandafter\relax\expandafter\detokenize\expandafter{\instr@tmpa#1{}{}#2}\relax%
\expandafter\@secondoftwo
\else
\expandafter\@firstoftwo
\fi
{#3}{#4}%
}
% this is \sitem from http://tex.stackexchange.com/a/52718/5049
\def\@pitem{%
\expandafter\let\expandafter\originallabel\csname labelenum\romannumeral\@enumdepth\endcsname
\expandafter\def\csname labelenum\romannumeral\@enumdepth\expandafter\endcsname\expandafter{%
\expandafter(\originallabel}%
\item
\expandafter\let\csname labelenum\romannumeral\@enumdepth\endcsname\originallabel
}
\long\def\pitem#1\end{%
\ifinstring{#1}{\item}
{\pitem@i#1\end}
{\pitem@ii#1\end}}
\long\def\pitem@i#1\item{%
\ifinstring{#1}{\pitem}
{\pitem@iii#1\item}
{\@pitem #1\unskip)\item}}
\long\def\pitem@ii#1\end{%
\ifinstring{#1}{\pitem}
{\pitem@iii#1\end}
{\@pitem #1\unskip)\end}}
\long\def\pitem@iii#1\pitem{%
\@pitem #1\unskip)\pitem}
\makeatother
\begin{document}
\begin{enumerate}
\item Really important
\item Quite important
\pitem If we have time
\pitem If we have time
\item Really important
\begin{enumerate}
\item Really important
\item Quite important
\pitem If we have time\par or change our mind
\item Really important
\item Quite important
\pitem If we have time
\end{enumerate}
\item Quite important
\pitem If we have time
\end{enumerate}
\end{document}
-
This has the same problem with blank lines between \item's that @egreg pointed out in my approach. – StrongBad Sep 14 '12 at 14:06
Yes, of course. But a blank line in a \pitem starts a new paragraph which naturally is also enclosed and thus places the closing parenthesis on the line below. Solution: don't end a \pitem with an empty line or comment the blank line if you want the visual separation of your items in the source. – clemens Sep 14 '12 at 14:13
I define two new macros \pitem and \@pitem and modify \@item. The \pitem macro is the same as \item, except it uses \@pitem. The \@pitem macro is the same as the modified \@item, except it sets a boolean to be true while the modified \@item sets the boolean to be false. I modify the enumerate environment to add a closing parenthesis if needed.
Blank line are allowed, although I am a little hesitant about the redefinition of \par to \relax if the next token is \end. I have no idea what \@endparenv does so I am ot happy that I just delete it, but it seems to work
\documentclass{article}
\usepackage{lipsum}
\usepackage{etoolbox}
\newbool{@pitem}
\makeatletter
\def\pitem{\@inmatherr\pitem\@ifnextchar[\@pitem{\@noitemargtrue \@pitem[(\@itemlabel]}}
\let\@pitem\@item
\pretocmd{\@item}{\ifbool{@pitem}{\unskip)}{}\boolfalse{@pitem}}{}{}
\pretocmd{\@pitem}{\ifbool{@pitem}{\unskip)}{}\booltrue{@pitem}}{}{}
\BeforeBeginEnvironment{enumerate}{%
\def\@endparenv{}
\let\item@par\par
\def\par{\@ifnextchar\item{\relax}{\@ifnextchar\pitem{\relax}{\@ifnextchar\par{\relax}{\@ifnextchar\end{\relax}{\item@par}}}}}
}
\AtEndEnvironment{enumerate}{\ifbool{@pitem}{\unskip)}{}\boolfalse{@pitem}}
\begin{document}
\begin{enumerate}
\item Really important
\item Quite important
\pitem If we have time
\item Whatever it takes
\begin{enumerate}
\pitem maybe
\item definitely
\end{enumerate}
\pitem first
\pitem second
\pitem third
\end{enumerate}
\lipsum[1-3]
\end{document}
-
You can't have two consecutive \pitem and no blank line is allowed before \pitem or \item. – egreg Sep 14 '12 at 13:45
@egreg thanks I had planned on testing consecutive \pitem's, but forgot. The blank line is a problem for my approach. – StrongBad Sep 14 '12 at 14:03
This approach does not accept nested \pitem. – Paul Gaborit Sep 15 '12 at 13:29
@PaulGaborit what is a nested \pitem? – StrongBad Sep 15 '12 at 13:41
@DanielE.Shub a "nested \pitem" is a \pitem into an enumerate into a \pitem... – Paul Gaborit Sep 15 '12 at 14:08
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2015-11-26 20:07:09
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https://testbook.com/objective-questions/mcq-on-triangles-congruence-and-similarity--5eea6a1039140f30f369e7ee
|
# Triangles, Congruence and Similarity MCQ Quiz - Objective Question with Answer for Triangles, Congruence and Similarity - Download Free PDF
Last updated on Dec 2, 2022
This Topic is generally considered an easy Topic to gain conceptual understanding but Triangles, Congruence and Similarity MCQs Quiz can be tricky to deal with. The trick here is to really understand and apply different properties and conditions of triangles. Practice Triangles, Congruence and Similarity objective questions with this curation of questions by Testbook and don’t miss out on any Triangles, Congruence and Similarity Question Answers. Also get some tips, tricks and shortcuts to solve them with ease.
## Latest Triangles, Congruence and Similarity MCQ Objective Questions
#### Triangles, Congruence and Similarity Question 1:
In the given figure, PQ ∥ SR. If the areas of Δ POQ and ΔSOR are 36 units and 49 units respectively. Find the area of Δ QOR.
1. 42
2. 35
3. 28
4. 56
Option 1 : 42
#### Triangles, Congruence and Similarity Question 1 Detailed Solution
Given:
PQ ∥ SR. Areas of Δ POQ and ΔSOR are 36 units and 49 units respectively.
Concept used:
Area of ratio of similar triangles is equal to the ratio of squares of their similar sides
Calculation:
In Δ POQ and Δ ROS,
∠ PQO = RSO (Alteranate angles)
∠ POQ = ROS (Vertically Opposite angles)
By A - A property, we can say that Δ POQ ∼ Δ ROS.
Now according to the provided concept,
(PO: RO)2 = 36: 49
⇒ PO : RO = 6 : 7
Now according to the question,
⇒ 6 = 36 (Compared to the ratio of the corresponding area of Δ)
⇒ 1 = 36/6 = 6
Now, RO = 7, which is a side of Δ QOR as well,
Comparing RO, with the A (Δ QOR), we get
⇒ 7 × 6 = 42 units2
The area of Δ QOR is 42 units.
#### Triangles, Congruence and Similarity Question 2:
ΔABC and ΔDEF are two triangles such that ΔABC ≅ ΔFDE. If AB = 5 cm, ∠B = 40° and ∠A = 80°, then which of the following options is true?
1. DF = 5 cm, ∠E = 60°
2. DE = 5 cm, ∠F = 60°
3. DE = 5 cm, ∠D = 60°
4. DE = 5 cm, ∠E = 60°
Option 1 : DF = 5 cm, ∠E = 60°
#### Triangles, Congruence and Similarity Question 2 Detailed Solution
Given:
ΔABC and ΔDEF are two triangles such that ΔABC ≅ ΔFDE.
AB = 5 cm, ∠B = 40° and ∠A = 80°
Concept used:
Congruency of triangle = if a triangle is congruent to another triangle then angle or side must be equal to the same triangle
Sum of angles of triangle = 180°
Calculations:
According to the question,
ΔABC ≅ ΔFDE then,
⇒ AB = FD
⇒ BC = DE
⇒ CA = EF
⇒ ∠A = ∠F = 80°
⇒ ∠B = ∠D = 40°
⇒ ∠C = ∠E
Through the Sum of angles,
180° = ∠A + ∠B + ∠C
⇒ 180° = 80° + 40° + ∠C
⇒ 180° = 120° + ∠C
⇒ 180° - 120° = ∠C
⇒ ∠C = 60°
Since ∠C = ∠E then ∠E = 60°
∴ The correct option is DF = 5 cm, ∠E = 60°.
#### Triangles, Congruence and Similarity Question 3:
In the following figure O is the center of a circle, Find the value of ∠ ADC + ∠ COB
1. 90 - α
2. 90 + α
3. 2α
4. α
Option 2 : 90 + α
#### Triangles, Congruence and Similarity Question 3 Detailed Solution
Concept Used:
Angles formed at the circumference of the same arc are equal in measure.
Angle at the center is twice the angle formed at the circumference.
Angle at the circumference formed at the diameter is 90°.
Calculation:
∠ ADB = 90° (angle formed on diamtere AB)
∠ BAC = ∠ CDB (angles formed on the same arc BC)
⇒ ∠ CDB = α
⇒ 90 = ∠ ADC + α
⇒ ∠ ADC = 90 - α
∠ COB = 2 × ∠ BAC
⇒ ∠ COB = 2α
⇒ 90 - α + 2α
⇒ 90 + α
∴ The value of ∠ ADC + ∠ COB is 90 + α
#### Triangles, Congruence and Similarity Question 4:
Find the length of AC in the Following Figure
1. 10
2. 14
3. 6
4. 12
Option 2 : 14
#### Triangles, Congruence and Similarity Question 4 Detailed Solution
Concept used:
In ΔABC Let CE, BD and AF be the cevians meet at a Concurrent Point O
then According to the Cevas theorem AD/DC × CF/FB × BE/EA = 1
Calculations:
According to Cevas Theorem
In ΔABC The cevians AF, CE and BD meet at a Concruent point P
Then According to Cevians Theorem AD/DC × BF/FC × BE/EA = 1
⇒ Let the Length of AD be x
⇒ x/4 × 3/3 × 2/5 = 1
⇒ x = 4 × 3 × 5 / 3 × 2 = 10
⇒ 10 + 4 = 14
#### Triangles, Congruence and Similarity Question 5:
In ABC, BP : PC = 2 : 3 & AQ : QC = 1 : 3 AS : SP = ?
1. $$\frac{5}{3}$$
2. $$\frac{6}{5}$$
3. $$\frac{5}{6}$$
4. none
Option 3 : $$\frac{5}{6}$$
#### Triangles, Congruence and Similarity Question 5 Detailed Solution
$$\rm \frac{{arASB}}{{arBSC}} = \frac{1}{{3unit}}$$
$$\rm \left[ \because{\frac{{ASQ}}{{SQC}} = \frac{1}{3}} \right]$$
$$\rm \frac{{arBSP}}{{arPSC}} = \left( {\frac{2}{3}} \right) \to 5unit$$
ArBSC same ∴ 15 unit
BSP = 2 × 3 = 6
PSC = 3 × 3 = 9
ASB = 1 × 5 = 5
$$\rm \therefore \;\frac{{AS}}{{SP}} = \frac{5}{6}$$
## Top Triangles, Congruence and Similarity MCQ Objective Questions
#### Triangles, Congruence and Similarity Question 6
The sides of similar triangles ΔPQR and ΔDEF are in the ratio 5 ∶ 6. If area of ΔPQR is equal to 75 cm2, what is the area of ΔDEF?
1. 150 cm2
2. 90 cm2
3. 108 cm2
4. 120 cm2
Option 3 : 108 cm2
#### Triangles, Congruence and Similarity Question 6 Detailed Solution
Given:
ΔPQR ∼ ΔDEF
The sides of ΔPQR and ΔDEF are in the ratio 5 ∶ 6.
ar(PQR) = 75 cm2
Concepts used:
The ratio of area of similar triangles is equal to the square of the ratio of sides of corresponding triangles.
Calculation:
ΔPQR ∼ ΔDEF
ar(PQR)/ar(DEF) = (Side of ΔPQR/Side of ΔDEF)2
⇒ 75/ar(DEF) = (5/6)2
⇒ ar(DEF) = 108 cm2
∴ Area of ΔDEF is equal to 108 cm2.
#### Triangles, Congruence and Similarity Question 7
ΔPQR inscribes in a circle with centre O. If PQ = 12 cm, QR = 16 cm and PR = 20 cm, find the circumradius of a triangle.
1. 10 cm
2. 8 cm
3. 6 cm
4. 20 cm
Option 1 : 10 cm
#### Triangles, Congruence and Similarity Question 7 Detailed Solution
Given:
In ΔPQR,
PQ = 12 cm, QR = 16 cm and PR = 20 cm
Concept used:
a, b and c denote the sides of the triangle and A denotes the area of the triangle,
Then the measure of the circumradius(r) is.
r = [abc/4A]
If the square of one side is equal to the sum of the squares of the other two sides, then the angle opposite the biggest side is a right angle.
Hypotenuse2 = Perpendicular2 + Base2
Calculation:
Here, we can see that
(20)2 = (16)2 + (12)2 = 400
⇒ PR2 = QR2 + PQ2
So, ΔPQR is a right angle triangle.
Area of ΔPQR = (½ ) × base × Perpendicular
⇒ Area of ΔPQR = (½ ) × 16 × 12
⇒ Area of ΔPQR = 96 cm2
Circumradius (r) = [abc/4 × Area]
Circumradius (r) = [(12 × 16 × 20)/4 × 96] = 10 cm
∴ The circumradius of a triangle is 10 cm.
For a right-angled triangle, the circumcenter lies at the midpoint of the hypotenuse. All the vertices of a triangle are at an equal distance from the circumcenter.
PO = QO = OR = r
⇒ PO = PR/2
⇒ PO = 20/2 = 10 cm
The circumradius of a triangle is 10 cm.
#### Triangles, Congruence and Similarity Question 8
ΔABC is inscribed in a circle with centre O. If AB = 17 cm, BC = 10 cm and AC = 9 cm, find the length of AO
1. 18 cm
2. 10.6 cm
3. 106 cm
4. 36 cm
Option 2 : 10.6 cm
#### Triangles, Congruence and Similarity Question 8 Detailed Solution
Concept used:
Length of circumradius = (A × B × C)/(4 × Δ)
where A, B, C are the lengths of the 3 sides of the triangle
Δ → Area of the triangle.
Area of triangle = √{s(s - a)(s - b)(s - c)}
where a, b, c are the lengths of the 3 sides of the triangle
s → Semiperimeter
Calculation:
s = (a + b + c)/2
⇒ s = (10 + 9 + 17)/2
⇒ s = 18
Area of ΔABC = √{18(18 - 10)(18 - 9)(18 - 17)
⇒ √(18 × 8 × 9 × 1)
⇒ 36 cm2
Circumradius of the triangle = (a × b × c)/4Δ
⇒ (10 × 17 × 9)/(4 × 36)
⇒ 10.6 cm
∴ Circumradius of the triangle is 10.6 cm
#### Triangles, Congruence and Similarity Question 9
ΔABC ~ ΔPQR, the areas of ΔABC and ΔPQR are 64 cm2 and 81 cm2, respectively and AD and PT are the medians of ΔABC and ΔPQR, respectively. If PT = 10.8 cm, then AD = ?
1. 9 cm
2. 12 cm
3. 8.4 cm
4. 9.6 cm
Option 4 : 9.6 cm
#### Triangles, Congruence and Similarity Question 9 Detailed Solution
Given:
ΔABC ~ ΔPQR
Area of ΔABC = 64 cm2
Area of ΔPQR = 81 cm2
PT = 10.8 cm
AD is the median of ΔABC.
PT is the median of ΔPQR
Concept:
The ratio of the areas of two similar triangles is equal to the ratio of the squares of the corresponding sides & medians.
$$\text{Area of (ΔABC)}\over{\text{Area of (ΔPQR)}}$$ = $$({AD\over PT})^2$$
Calculation:
$$\text{Area of (ΔABC)}\over{\text{Area of (ΔPQR)}}$$ = $$({AD\over PT})^2$$
⇒ $$64\over81$$ = $$({AD\over PT})^2$$
$$AD\over PT$$ = $$\sqrt{64\over81}$$ = $$8\over9$$
$$AD\over 10.8$$ = $$8\over9$$
AD = $${8\times10.8}\over9$$ = 9.6 cm
#### Triangles, Congruence and Similarity Question 10
Choose the CORRECT option if the two sides of a triangle are of length 3 cm and 8 cm and the length of its third side is x cm.
1. 1 < x < 11
2. x < 11
3. x > 11
4. 5 < x < 11
Option 4 : 5 < x < 11
#### Triangles, Congruence and Similarity Question 10 Detailed Solution
Given that,
The two sides of a triangle are of length 3 cm and 8 cm and the length of its third side is x cm.
As we know,
Sum of two sides of triangle is always greater than third side of the triangle.
∴ Sum of two sides of triangle > third side of the triangle.
⇒ 3 + 8 > Third side
⇒ 11 > x
Also,
Another case will be,
⇒ x + 3 > 8
⇒ x > 8 - 3
⇒ x > 5
∴ 5 < x < 11
#### Triangles, Congruence and Similarity Question 11
In ΔABC, ∠A = 135°, CA = 5√2 cm and AB = 7 cm. E and F are midpoints of sides AC and AB, respectively. The length of EF (in cm) is:
1. 5.5
2. 6.5
3. 6
4. 5
Option 2 : 6.5
#### Triangles, Congruence and Similarity Question 11 Detailed Solution
Given:
AB (c) = 7 cm, CA (b) = 5√2 cm, BC = a
E and F are the mid-points of AC & AB.
∠A = 135°
Concept:
By cosine rule
Cos A = (b2 + c2 - a2)/ 2bc
Mid-point theorem
EF = BC/2
Calculation:
According to the cosine rule
$$cos135^0= \frac{(5\sqrt2)^2 + (7)^2 - (a)^2}{2\times7\times5\sqrt2}$$
⇒ $$\frac{-1}{\sqrt2}= \frac{(5\sqrt2)^2 + (7)^2 - (a)^2}{2\times7\times5\sqrt2}$$
⇒ $$-70= 50 + 49 - a^2$$
⇒ a2 = 169
⇒ a = 13, a ≠ - 13
⇒ BC = 13
From formula used
EF = BC/2 = 13/2 cm
∴ EF = 6.5 cm
#### Triangles, Congruence and Similarity Question 12
In the figure, ∠BAC = ∠BCD, AB = 32 cm and BD = 18 cm then Find the length of side BC.
1. 20 cm
2. 24 cm
3. 30 cm
4. 28 cm
Option 2 : 24 cm
#### Triangles, Congruence and Similarity Question 12 Detailed Solution
GIVEN:
∠BAC = ∠BCD, AB = 32 cm and BD = 18 cm
CONCEPT:
If two triangles are similar, the ratio of respective sides will be equal.
CALCULATION:
In triangle ABC and CBD;
∠BAC = ∠BCD
∠B is common
Hence, triangles ABC and CBD are similar by AA similarity.
∴ AB/CB = BC/BD
⇒ BC2 = 32 × 18 = 576
∴ BC is 24 cm
#### Triangles, Congruence and Similarity Question 13
In a ΔABC right angled at B, D is a point on AC such that BD is an angle bisector of B. If AD = 12 cm, CD = 16 cm then find the perimeter of triangle ABC.
1. 49.6 cm
2. 67.2 cm
3. 56.4 cm
4. 48 cm
Option 2 : 67.2 cm
#### Triangles, Congruence and Similarity Question 13 Detailed Solution
Given
AD = 12 cm, CD = 16 cm
Formula used
Angle Bisector theorem,
Perimeter of triangle = Sum of all sides
Calculation
In Δ ABC, BD is an angle bisector of ∠B
⇒ 12/16 = AB/BC
⇒ AB : BC = 3 : 4
From the triplets of right angle triangle
If AB = 3x and BC = 4x
then AC = 5x
AC = 12 + 16 = 28 cm
⇒ 5x = 28 cm
⇒ x = 5.6 cm
Perimeter of triangle = 5x + 3x + 4x = 12x
⇒ 67.2 cm
∴ The required answer is 67.2 cm
#### Triangles, Congruence and Similarity Question 14
In ΔXYZ, XY and XZ are 20 cm and 25 cm respectively, XP is angle bisector of ∠YXZ, YP = a cm and PZ = (a + 3) cm. If I is the incenter of the triangle then find the ratio of XI ∶ IP.
1. 5 ∶ 3
2. 4 ∶ 5
3. 3 ∶ 5
4. 5 ∶ 4
Option 1 : 5 ∶ 3
#### Triangles, Congruence and Similarity Question 14 Detailed Solution
Given:
XY = 20 cm
XZ = 25 cm
YP = a cm
PZ = (a + 3) cm
Concept used:
In a given triangle, if AD is angle bisector of ∠BAC, and I is incenter then
BD ∶ DC = c ∶ b
AI ∶ ID = (c + b) ∶ a
Calculation:
As, XP is angle bisector and I is incenter, then
YP ∶ PZ = XY ∶ XZ
⇒ a ∶ (a + 3) = 20 ∶ 25
⇒ a/(a + 3) = 4/5
⇒ 5a = 4a + 12
⇒ a = 12 cm
YZ = a + a + 3 = 2a + 3
⇒ YZ = 27 cm
XI ∶ IP = (XY + XZ) ∶ YZ
⇒ XI ∶ IP = (20 + 25) ∶ 27 = 45 ∶ 27
XI IP is 5 3
#### Triangles, Congruence and Similarity Question 15
In ΔABC, MN∥BC, the area of quadrilateral MBCN = 130 cm2. If AN : NC = 4 : 5, then the area of ΔMAN is:
1. 45 cm2
2. 65 cm2
3. 40 cm2
4. 32 cm2
Option 4 : 32 cm2
#### Triangles, Congruence and Similarity Question 15 Detailed Solution
Given,
the area of quadrilateral MBCN = 130 cm2.
AN : NC = 4 : 5
Hence, AC = 4 + 5 = 9
In ΔABC, If MN∥BC, then
Area of ΔAMN/area of ΔABC = (AN/AC)2
Area of ΔAMN/area of ΔABC = (4/9)2 = 16/81
Area of ΔAMN = 16 unit and area of ΔABC = 81 unit
Now, Area of quadrilateral MBCN = area of ΔABC - area of ΔAMN
⇒ 81 - 16 unit = 130 cm2
⇒ 65 unit = 130 cm2
⇒ 1 unit = 130/65 = 2 cm2
∴ Area of ΔAMN = 16 × 2 = 32 cm2
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2022-12-05 00:15:43
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http://mathhelpforum.com/advanced-algebra/84922-l-t-problem.html
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# Math Help - L.T problem.....
1. ## L.T problem.....
Q:let T from R^3 to R^3 be a linear transformation and I be identity transformation of R^3.If there is a scalar c and a non zero vector x belongs to R^3 s.t T(x)=cx, then rank(T-cI)
A)can'tbe 0
B)can't be 1
C)can't be 2
D)can't be 3
2. Originally Posted by Mathventure
Q:let T from R^3 to R^3 be a linear transformation and I be identity transformation of R^3.If there is a scalar c and a non zero vector x belongs to R^3 s.t T(x)=cx, then rank(T-cI)
A) can'tbe 0
B) can't be 1
C) can't be 2
D) can't be 3
D) is the answer. (the rank-nullity theorem)
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2015-11-25 03:18:41
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https://dsp.stackexchange.com/questions/10547/stability-varying-with-order
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# Stability varying with order
I have been doing some research into modelling acoustic spaces, and (with help from this site) I've managed to take the frequency response of fibrous layer model, convert it to a reflection response as a target for an IIR, and then find the polynomial coefficients for it using FDLS. All good so far.
I performed the usual BIBO stability test of finding the magnitude of the IIR denominator roots, and with a 4th order filter everything was fine (<=1.0). But increasing the order, even by just one, then it became unstable.
My question is: What does the order actually represent response-wise? I always assumed it determined the sharpest change in direction of the frequency response i.e. the 'jagged-ness' or complexity of the response curve. If that's true, then my filter is unstable, but the few poles I've calculated just happen to be inside the unit circle.
But is that true?
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2022-08-16 17:13:29
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https://peytondmurray.github.io/coding/lammps-installation-manjaro/
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# LAMMPS Installation in Manjaro
I’ve been interested in doing some molecular dynamics (MD) simulations for a project I’ve been thinking about for a long time, but it’s only recently that I’ve had the time to start tinkering with MD simulation packages. There are a few large projects to choose from if you’re looking to get into MD simulations, with GROMACS and LAMMPS being two of the more widely used packages. Although the literature suggests that GROMACS can be used for MD simulations of crystalline systems, it just seemed to me like it has been primarily used for simulating biological systems - proteins and that kind of stuff. So I decided to check out LAMMPS, an MD simulator maintained by Sandia, with contributions from people all over the world.
LAMMPS comes with a lot of extensions which add various functionality to the simulator, so building the source code is recommended because you can choose what packages you need for your specific application. Depending on your system, you can also find prebuilt binaries, but to take full advantage of the optimizations available to your system, building from source is the best. Fortunately, LAMMPS uses the CMAKE meta-build system. If you’re not familiar with CMAKE, it’s a tool which creates the files necessary to compile source code. On Linux, it builds makefiles; on Windows, you can use it to create Visual C++ project files. It can do lots of stuff beyond just creating the instructions for compiling and linking your source code for whatever platform you are using, but it’s not the focus of this post, so I’m going to move on.
Since LAMMPS can be built with tons of different packages, based on the description of the package in the LAMMPS documentation, I took an educated guess as to whether or not I was going to want to have it, and made a shortlist of what to build. Each package has a short summary of what it does as a note to myself. Packages with a * denote ones that require additional CMAKE variables to be defined, with the values needed for my system noted below.
# Packages
• ASPHERE - Computes, time-integration fixes, and pair styles for aspherical particle models including ellipsoids, 2d lines, and 3d triangles.
• BODY - Body-style particles with internal structure. Computes, time-integration fixes, pair styles, as well as the body styles themselves. See the Howto body doc page for an overview.
• CLASS2 - Bond, angle, dihedral, improper, and pair styles for the COMPASS CLASS2 molecular force field.
• CORESHELL - Compute and pair styles that implement the adiabatic core/shell model for polarizability.
• DIPOLE - An atom style and several pair styles for point dipole models with short-range or long-range interactions.
• GPU* - GPU pair styles and other stuff. KOKKOS uses GPU-enabled styles
• GPU_API=cuda
• GPU_ARCH=sm_60
• CUDPP_OPT=yes
• GRANULAR - Pair styles and fixes for finite-size granular particles, which interact with each other and boundaries via frictional and dissipative potentials.
• KIM* - Knowledge Base for Interatomic Models repository of interatomic potentials.
• KOKKOS* - Parallelization (including GPU) for lots of models.
• KOKKOS_ARCH=HSW;Pascal61
• KOKKOS_ENABLE_CUDA=yes
• KOKKOS_ENABLE_OPENMP=yes
• CMAKE_CXX_COMPILER=<path to nvcc_wrapper included with LAMMPS source>
• KSPACE - Long range coulombic solvers
• MANYBOCY - Manybody and bond-order potentials
• MC - Several fixes and a pair style that have Monte Carlo (MC) or MC-like attributes.
• MISC - A variety of compute, fix, pair, dump styles with specialized capabilities that don’t align with other packages.
• OPT - Optimized pair styles for multiple cores
• PERI - Particle-based meshless continuum model
• PYTHON - python command which allows python code to be executed from a LAMMPS input script
• PYTHON_EXECUTABLE=<path to python bin>
• QEQ - Fixes for charge equilibration via different algorthims
• REPLICA - Nudged elastic band methods, other algorithms used in running multiple LAMMPS simulations
• RIGID - Fixes which enforce rigid constraints on collections of atoms or particles.
• SHOCK - Fixes for running impact simulations where a shock-wave passes through a material.
• SPIN - Model atomic magnetic spins classically, coupled to atoms moving in the usual manner via MD. Various pair, fix, and compute styles.
• USER-COLVARS - COLVARS stands for collective variables, which can be used to implement various enhanced sampling methods, including Adaptive Biasing Force, Metadynamics, Steered MD, Umbrella Sampling and Restraints.
• USER-DIFFRACTION - Two computes and a fix for calculating x-ray and electron diffraction intensities based on kinematic diffraction theory.
• USER-DRUDE - Fixes, pair styles, and a compute to simulate thermalized Drude oscillators as a model of polarization.
• USER-FEP - This package provides methods for performing free energy perturbation simulations by using a fix adapt/fep command with soft-core pair potentials, which have a “soft” in their style name.
• USER-MISC - A potpourri of (mostly) unrelated features contributed to LAMMPS by users. Each feature is a single fix, compute, pair, bond, angle, dihedral, improper, or command style.
• USER-MEAMC - A pair style for the modified embedded atom (MEAM) potential translated from the Fortran version in the MEAM package to plain C++.
• USER-OMP - Hundreds of pair, fix, compute, bond, angle, dihedral, improper, and kspace styles which are altered to enable threading on many-core CPUs via OpenMP directives.
• USER-PHONON - A fix phonon command that calculates dynamical matrices, which can then be used to compute phonon dispersion relations, directly from molecular dynamics simulations.
• USER-QTB - Two fixes which provide a self-consistent quantum treatment of vibrational modes in a classical molecular dynamics simulation.
• USER-REAXC - A pair style which implements the ReaxFF potential in C/C++ (in contrast to the REAX package and its Fortran library). ReaxFF is universal reactive force field.
• USER-TALLY - Several compute styles that can be called when pairwise interactions are calculated to tally information (forces, heat flux, energy, stress, etc) about individual interactions.
• USER-VTK - VTK output
# Get it in one CMAKE command
If the LAMMPS git repo is cloned, and a build directory is created in the root directory, the CMAKE part of the building process can be completed in one go. You’ll obviously have to change the part about python executable, but having it in one command is nice.
cmake -G "Unix Makefiles" -D PKG_ASPHERE=yes -D PKG_BODY=yes -D PKG_CLASS2=yes -D PKG_CORESHELL=yes -D PKG_DIPOLE=yes -D PKG_GPU=yes -D GPU_API=cuda -D GPU_ARCH=\<gpu_architecture\> -D CUDPP_OPT=yes -D PKG_GRANULAR=yes -D PKG_KIM=yes -D DOWNLOAD_KIM=yes -D PKG_KSPACE=yes -D PKG_MANYBODY=yes -D PKG_MC=yes -D PKG_MISC=yes -D PKG_OPT=yes -D PKG_PERI=yes -D PKG_PYTHON=yes -D PKG_QEQ=yes -D PKG_REPLICA=yes -D PKG_RIGID=yes -D PKG_SHOCK=yes -D PKG_SPIN=yes -D PKG_USER-COLVARS=yes -D PKG_USER-DIFFRACTION=yes -D PKG_USER-DRUDE=yes -D PKG_USER-FEP=yes -D PKG_USER-MISC=yes -D PKG_USER-MEAMC=yes -D PKG_USER-OMP=yes -D PKG_USER-PHONON=yes -D PKG_USER-QTB=yes -D PKG_USER-REAXC=yes -D PKG_USER-TALLY=yes -D PKG_USER-VTK=yes -D PYTHON_EXECUTABLE=\<path to python bin\> -D BUILD_OMP=yes -D BUILD_EXE=yes -D BUILD_LIB=yes -D BUILD_SHARED_LIBS=yes ../cmake
# KOKKOS Broken?
That being said, I could not get KOKKOS to compile almost no matter what I did. I followed the instructions on the LAMMPS website only to discover that gcc 8 is not supported. I tried using gcc 4.9, which is on the Arch User Repository, but that didn’t work either. In any case, choosing not to build KOKKOS seems bad, since it offers what seems like a lot of GPU-enabled features. I’ll probably revisit this issue in the future, and if I find anything else I’ll update this post.
Categories:
Updated:
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2020-08-12 13:09:54
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http://hellenicaworld.com/Science/Mathematics/en/Homomorphicequivalence.html
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### - Art Gallery -
In the mathematics of graph theory, two graphs, G and H, are called homomorphically equivalent if there exists a graph homomorphism $${\displaystyle f\colon G\to H}$$ and a graph homomorphism $${\displaystyle g\colon H\to G}$$. An example usage of this notion is that any two cores of a graph are homomorphically equivalent.
Homomorphic equivalence also comes up in the theory of databases. Given a database schema, two instances I and J on it are called homomorphically equivalent if there exists an instance homomorphism $${\displaystyle f\colon I\to J}$$ and an instance homomorphism $${\displaystyle g\colon J\to I}.$$
In fact for any category C, one can define homomorphic equivalence. It is used in the theory of accessible categories, where "weak universality" is the best one can hope for in terms of injectivity classes; see [1]
References
Adamek and Rosicky, "Locally Presentable and Accessible Categories".
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2021-04-15 17:51:52
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https://www.physicsforums.com/threads/conditional-probability-traffic-light-question.94518/
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# Conditional Probability Traffic light question
1. Oct 13, 2005
### Pure Canuck
Hey guys Me and my friend just got this question and it seems easy but i just want to make sure we are right anyway here it is:
A road has two stoplights at consecutive intersections. The prob. of a red at the first is 0.55 and the probability of a green at the second, give a green at light oine is .75
Find the prob of a green at both intersections:
Givens = (r1 = .55) (g2|g1=.75)
now i believe its simply as just r1*.75.
which is like .33
Anybody know if i did this right?
Thanks
2. Oct 13, 2005
### *melinda*
$P(r_1 )=0.55$ and $P(g_2 |g_1 )=0.75$
but I don't know how you got your answer because .55*.75 = .4125, though I do agree that .33 is very close to the answer, depending on how you round the decimal.
3. Oct 14, 2005
### iNCREDiBLE
Hint: http://mathworld.wolfram.com/ConditionalProbability.html" [Broken].
Just use the formula.
Last edited by a moderator: May 2, 2017
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2017-06-25 14:22:36
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https://blog.r6l7.com/it-works-nix/
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Well, that was an ordeal. It took the better part of a week, but I have a server again.
This blogging platform was not part of the problem. It was a joy to work with. Hats off to the people at Ghost
The reason it took so long to setup is that it's running on an OS from the future. It's called NixOS, and some of the time it's really great.
## Nix
The headline feature for this operating system is that it uses Nix, the purely functional package manager. With Nix, all packages are given unique names that include a hash of all their inputs, including not just their sources but also the compilers used, the build scripts, and the rest of the environment. Inputs that are not explicitly specified are not present for the package build process, so it's really hard to create hidden dependencies. It's kind of like deb or rpm, but a little better about tracking dependencies.
Its approach to deploying those packages is unique. Rather than install packages in place, it stashes them all in the Nix store (located at /nix/store) and uses a forest of symlinks and \$PATH entries to put them together into a useful combination. Want to use a new version of Python for a little while, without reconfiguring your system? Just invoke nix-shell with the proper incantations and it will build you a new environment and start a shell in it. With a system like this, package rollbacks are pretty easy, too.
If you're a Haskell programmer and you haven't heard of Nix before, you may be salivating right now. That language has an unforuntate combination of being finicky about package versions, and a tooling system that's not very good about installing two versions of the same library side-by-side. Nix's features will be of useful for lot of people, but Haskell programmers have more reasons to be excited about it.
## NixOS
All that's pretty neat, and an operating system based on Nix would be interesting in of itself. But NixOS goes beyond that starting point.
NixOS puts itself in charge of building /etc and other config paths based on a single configuration.nix file. It does this using the same domain-specific language as the Nix package manager. The language has all the usual features, like functions, variables, and importing other files. It turns out this is a great idea.
I never noticed it before, but there's a lot of redundant work in configuring a typical Linux box. Ports and user names wind up in several different config files, and the system doesn't work if they don't line up. It's much easier to manage these things when a port number or user name can be specified as a variable which can then be pulled into several different config files.
Although the end result is an /etc that should look familiar to most admins, the work of formatting the Nix configs into the usual file formats is well hidden. That's another benefit of using a programming language for this; all the logic for writing these files can be handled in a library. The admin sees a single uniform interface for configuring everything.
Almost everything is written to be easy to use. Here's one of my favorites:
ghostContentPath = "/var/ghost/content";
services.tarsnap.enable = true;
services.tarsnap.config.ghost.directories = [ ghostContentPath ];
Those three lines enable tarsnap daily backups for this blog!
There's lots more goodies like this in the NixOS Manual's Appendix.
## NixOps
Finally, there's a tool that ties this all into the cloud. This makes it easy to spin up an EC2 or GCE instance that matches that specification. Or you can build a template and stamp out a dozen different instances, with each one parameterized slightly differently. When the machine specifications are just expressions in a programming language, they can be copied, modified and instantiated easily.
Deploying changes is easy, too. Just update the config files and run nixops deploy. The program will take care of starting or stopping machines, installing packages, and restarting services.
At this point, it starts to encroach on Puppet and Chef's territory. Which is a good thing, since those tools seem to be regarded as (at best) a necessary evil.
## My Experience
The down-side is that actually making these packages can be a bit of a pain. It's a young project. There's very little documentation or examples, so you're on your own once you've strayed from the well-traveled path. The Nix interpreter's error messages are often confusing. Perhaps worst of all, most editors don't have syntax highlighting for .nix files yet.
The reason it took me so long to build this site is that I had to build a bunch of my packages from scratch without much help from documentation.
Most of my work is too crude to be upstreamed into the nixpkgs tree, but I can still post it online. Maybe this can save someone else some time.
https://github.com/richardlarocque/nix-configs
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2018-12-19 08:34:32
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https://math.stackexchange.com/questions/2723407/examples-of-division-outside-of-numbers
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# Examples of division outside of numbers
There are many examples of addition and multiplication outside of numbers. In certain cases addition can be seen as essentially combination or merging. Likewise, multiplication can be seen as cloning or duplication.
For letters for example:
\begin{align} a + b &= ab\\ a^2 &= aa\\ a * 3 &= aaa \end{align}
Well, for $+$ you can combine two non-numbers, not sure about multiplication (non-number $*$ number, don't know if there is a non-number $*$ non-number).
Wondering if there is any parallel for division $\div$:
$$\texttt{nonnumber} \div \texttt{nonnumber}$$
or even just
$$\texttt{nonnumber} \div \texttt{number}$$
• What you describe reminds me of free groups, where finite strings of letters and their putative "reciprocals" are made to act as elements of a group. – hardmath Apr 5 '18 at 14:35
In your specific example, yes, you can define the operation of concatenation and use the $+$ symbol for it. You have the monoid of strings. A monoid is like a group but does not require inverses. You have an identity element, which is the empty string. It is natural to define multiplication by a natural number as repeated addition. Your second and third lines use the operation in that way but use different notation for it. The second uses a power notation while the third uses $*$. Let us use $*$ for your multiplication by a natural and $\cdot$ for multiplication in the naturals. $*$ is a perfectly well defined operation that concatenates a number of copies of the same string, so you could write $ab * 2=abab$ for example. It plays nicely with multiplication in the naturals in that $(ab * 2) * 3=ab *(2 \cdot 3)$ We often use this for groups where we write $na$ with $n \in \Bbb N$ and $a$ in the group as the sum of $n$ copies of $a$.
It is easy to define division by a natural. Just like in the naturals, there may not be a result. You can just take it to be the inverse of $*$ when it exists, so $aaa \div 3 = a$. We can use $\div$ for your division of strings by naturals and $/$ for division in the naturals. Again division in the naturals plays nice with your $*$ in that $(ab*6) \div 2 = ab *(6/2)$
• In the naturals you cannot divide $7$ by $3$. Similarly, the obvious definition of $\div$ requires that the string you are dividing be a repeat. I think you mean to say that $abc \div 3$ does not have a result. – Ross Millikan Apr 5 '18 at 16:54
If you are programming or using categories or universal algebra then in some sense the type of the objects does not matter. In particular there is no really reason to conceptualize a notion of "number" you just describe operations on your objects. For example, in functional programming the concept of a flat-map (or map-reduce) is regarded by some as a multipliction metaphor. That is made precise by extracting the abstraction of a monad functor F with a join $F\circ F\to F$. E.g. a List of Lists of integers is easily "joined" together into a single List of integers. For all mathematical purposes that is in a product, even if you wouldn't regard lists as numbers.
As for division then, if division to you means $a\div b$, i.e. a function def div(a:A,b:A):A then its can be as general as any multiplication metaphor, e.g. operating on sets or lists, or trees, elephants. You might then ask what makes it division verses a multiplication, and for that I would suggest that you have it in the company of some other operation you already called multiplication and which is in a meaningful sense reciprocal to your division. E.g. if you have $a\times b$ and $a\div b$ then $(a\times b)\div b=a$ or some such identity.
But as for caring if $a$ and $b$ are "numbers", there is no need for that on a mathematics level at least. Maybe a philosopher would object.
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2019-04-18 16:18:49
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https://www.physicsforums.com/threads/mathematic-inductive-proof-question.490419/
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# Mathematic Inductive Proof question
## Homework Statement
Give a proof by Mathematical Induction of the following:
For all integers n>=3, (n^2 - 3n + 2) is positive.
## The Attempt at a Solution
Hey guys, this is a problem from my discrete mathematics study guide. Here's what I got so far:
Proof: n-initial=3
Basis step: If n=3, then LHS=3 and RHS = (3^2 - 3(3) + 2) = 2 -> positive
Induction: Assume that (n^2 - 3n + 2) is positive for arbitrary n>=3
Now I'm not sure about how to actually go about the proof. I understand that we then show the induction hypothesis working for n+1 but I'm not sure how to put this together.
Something like: (n+1)^2 - 3(n+1) + 2 = n^2 - n....
EDIT: I see, so then using (n^2 - n) and plugging in 3 I get (3^2 - 3 = 6) which is equal to (4^2 - 3(4) + 2 = 6) -> positive. Would this be a complete proof?
Last edited:
SammyS
Staff Emeritus
Homework Helper
Gold Member
Assume that n2 - 3n + 2 > 0 . Now, show that (n+1)2 - 3(n+1) + 2 > 0 .
It may also be the case that you need to use the fact that n ≥ 3.
Well (n+1)^2 - 3(n+1) + 2 simplifies to n^2 - n.
How do I show that n^2 - n > 0 ?
n^2 - n > 0 <=> n^2 > n, and because your n is greater than or equal to 3, there is no case that shows n^2 < n, or even equal.
HallsofIvy
$n^2- n= n(n- 1)$.
n> 0 and, since $n\ge 3$, n-1> 0.
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2021-06-13 07:22:48
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https://nebusresearch.wordpress.com/tag/agnes/
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## Reading the Comics, March 14, 2021: Pi Day Edition
I was embarrassed, on looking at old Pi Day Reading the Comics posts, to see how often I observed there were fewer Pi Day comics than I expected. There was not a shortage this year. This even though if Pi Day has any value it’s as an educational event, and there should be no in-person educational events while the pandemic is still on. Of course one can still do educational stuff remotely, mathematics especially. But after a year of watching teaching on screens and sometimes doing projects at home, it’s hard for me to imagine a bit more of that being all that fun.
But Pi Day being a Sunday did give cartoonists more space to explain what they’re talking about. This is valuable. It’s easy for the dreadfully online, like me, to forget that most people haven’t heard of Pi Day. Most people don’t have any idea why that should be a thing or what it should be about. This seems to have freed up many people to write about it. But — to write what? Let’s take a quick tour of my daily comics reading.
Tony Cochran’s Agnes starts with some talk about Daylight Saving Time. Agnes and Trout don’t quite understand how it works, and get from there to Pi Day. Or as Agnes says, Pie Day, missing the mathematics altogether in favor of the food.
Scott Hilburn’s The Argyle Sweater is an anthropomorphic-numerals joke. It’s a bit risqué compared to the sort of thing you expect to see around here. The reflection of the numerals is correct, but it bothered me too.
Georgia Dunn’s Breaking Cat News is a delightful cute comic strip. It doesn’t mention mathematics much. Here the cat reporters do a fine job explaining what Pi Day is and why everybody spent Sunday showing pictures of pies. This could almost be the standard reference for all the Pi Day strips.
Bill Amend’s FoxTrot is one of the handful that don’t mention pie at all. It focuses on representing the decimal digits of π. At least within the confines of something someone might write in the American dating system. The logic of it is a bit rough but if we’ve accepted 3-14 to represent 3.14, we can accept 1:59 as standing in for the 0.00159 of the original number. But represent 0.0015926 (etc) of a day however you like. If we accept that time is continuous, then there’s some moment on the 14th of March which matches that perfectly.
Jef Mallett’s Frazz talks about the eliding between π and pie for the 14th of March. The strip wonders a bit what kind of joke it is exactly. It’s a nerd pun, or at least nerd wordplay. If I had to cast a vote I’d call it a language gag. If they celebrated Pi Day in Germany, there would not be any comic strips calling it Tortentag.
Steenz’s Heart of the City is another of the pi-pie comics. I do feel for Heart’s bewilderment at hearing π explained at length. Also Kat’s desire to explain mathematics overwhelming her audience. It’s a feeling I struggle with too. The thing is it’s a lot of fun to explain things. It’s so much fun you can lose track whether you’re still communicating. If you set off one of these knowledge-floods from a friend? Try to hold on and look interested and remember any single piece anywhere of it. You are doing so much good for your friend. And if you realize you’re knowledge-flooding someone? Yeah, try not to overload them, but think about the things that are exciting about this. Your enthusiasm will communicate when your words do not.
Dave Whamond’s Reality Check is a pi-pie joke that doesn’t rely on actual pie. Well, there’s a small slice in the corner. It relies on the infinite length of the decimal representation of π. (Or its representation in any integer base.)
Michael Jantze’s Studio Jantze ran on Monday instead, although the caption suggests it was intended for Pi Day. So I’m including it here. And it’s the last of the strips sliding the day over to pie.
But there were a couple of comic strips with some mathematics mention that were not about Pi Day. It may have been coincidence.
Sandra Bell-Lundy’s Between Friends is of the “word problem in real life” kind. It’s a fair enough word problem, though, asking about how long something would take. From the premises, it takes a hair seven weeks to grow one-quarter inch, and it gets trimmed one quarter-inch every six weeks. It’s making progress, but it might be easier to pull out the entire grey hair. This won’t help things though.
Darby Conley’s Get Fuzzy is a rerun, as all Get Fuzzy strips are. It first (I think) ran the 13th of September, 2009. And it’s another Infinite Monkeys comic strip, built on how a random process should be able to create specific outcomes. As often happens when joking about monkeys writing Shakespeare, some piece of pop culture is treated as being easier. But for these problems the meaning of the content doesn’t count. Only the length counts. A monkey typing “let it be written in eight and eight” is as improbable as a monkey typing “yrg vg or jevggra va rvtug naq rvtug”. It’s on us that we find one of those more impressive than the other.
And this wraps up my Pi Day comic strips. I don’t promise that I’m back to reading the comics for their mathematics content regularly. But I have done a lot of it, and figure to do it again. All my Reading the Comics posts appear at this link. Thank you for reading and I hope you had some good pie.
I don’t know how Andertoons didn’t get an appearance here.
## Reading the Comics, February 21, 2020: February 21, 2020 Edition
So way back about fifty years ago, when pop science started to seriously explain how computers worked, and when the New Math fad underscored how much mathematics is an arbitrary cultural choice, the existence of number bases other than ten got some publicity. This offered the chance for a couple of jokes, or at least things which read to pop-science-fans as jokes. For example, playing on a typographical coincidence between how some numbers are represented in octal (base eight) and decimal (base ten), we could put forth this: for computer programmers Halloween is basically another Christmas. After all, 31 OCT = 25 DEC. It’s not much of a joke, but how much of a joke could you possibly make from “writing numbers in different bases”? Anyway, Isaac Asimov was able to make a short mystery out of it.
Tony Cochrane’s Agnes for the 21st is part of a sequence with Agnes having found some manner of tablet computer. Automatic calculation has always been a problem in teaching arithmetic. A computer’s always able to do more calculations, more accurately, than a person is; so, whey do people need to learn anything about how to calculate? The excuse that we might not always have a calculator was at least a little tenable up to about fifteen years ago. Now it’d take a massive breakdown in society for computing devices not to be pretty well available. This would probably take long enough for us to brush up on long division.
It’s more defensible to say that people need to be able to say whether an answer is plausible. If we don’t have any expectations for the answer, we don’t know whether we’ve gone off and calculated a wrong thing. This is a bit more convincing. We should have some idea whether 25, 2500, or 25 million is the more likely answer. That won’t help us spot whether we made a mistake and got 27 instead of 25, though. It does seem reasonable to say that we can’t appreciate mathematics, so much of which is studying patterns and structures, without practicing. And arithmetic offers great patterns and structures, while still being about things that we find familiar and useful. So that’s likely to stay around.
John Rose’s Barney Google and Snuffy Smith for the 21st is a student-subverting-the-blackboard-problem joke. Jughaid’s put the arithmetic problems into terms of what he finds most interesting. To me, it seems like if this is helping him get comfortable with the calculations, let him. If he does this kind of problem often enough, he’ll get good at it and let the false work of going through sports problems fade away.
Stephan Pastis’s Pearls Before Swine for the 21st sees Pig working through a simple Retirement Calculator. He appreciates the mathematics being easy. A realistic model would have wrinkles to it. For example, the retirement savings would presumably be returning interest, from investments or from simple deposit accounts. Working out how much one gets from that, combined with possibly spending down the principal, can be involved. But a rough model doesn’t need this sort of detailed complication. It can be pretty simple, and still give you some guidance to what a real answer should look like.
John Zakour and Scott Roberts’s Working Daze for the 21st is a joke about how guys assuming that stuff they like is inherently interesting to other people. In this case, it’s hexadecimal arithmetic. That’s at least got the slight appeal that we’ve settled on using a couple of letters as numerals for it, so that wordplay and word-like play is easier than it is in base ten.
And this wraps up a string of comic strips all with some mathematical theme that all posted on the same day. I grant none of these get very deep into mathematical topics; that’s all right. There’ll be some more next week in a post at this link. Thank you.
## Reading the Comics, February 8, 2020: Exams Edition
There were a bunch of comic strips mentioning some kind of mathematical theme last week. I need to clear some out. So I’ll start with some of the marginal mentions. Many of these involve having to deal with exams or quizzes.
Jonathan Mahood’s Bleeker: The Rechargeable Dog from the 3rd started a sequence about the robot dog helping Skip with his homework. This would include flash cards, which weren’t helping, in preparation for a test. Bleeker would go to slightly ridiculous ends, since, after all, you never know when something will click.
There are different ways to find square roots. (I can guarantee that Skip wasn’t expected to use this one.) The term ‘root’ derives from an idea that the root of a number is the thing that generates it: 3 is a square root of 9 because multiplying 3’s together gives you 9. ‘Square’ is I have always only assumed because multiplying a number by itself will give you the area of a square with sides of length that number. This is such an obvious word origin, though, that I am reflexively suspicious. Word histories are usually subtle and capricious things.
Bill Watterson’s Calvin and Hobbes for the 3rd began the reprint of a storyling based on a story-problem quiz. Calvin fantasizes solving it in a wonderful spoof of hardboiled detective stories. There is a moment of Tracer Bullet going over exactly what information he has, which is a good first step for any mathematics problem. I assume it’s also helpful for solving real mysteries.
The strip for the 8th closing the storyline has a nice example of using “billion” as a number so big as to be magical, capable of anything. Big numbers can do strange and contrary-to-intuition things. But they can be reasoned out.
Tony Cochran’s Agnes for the 4th sees the title character figuring she could sell her “personal smartness”. Her best friend Trout wonders if that’s tutoring math or something. (Incidentally, Agnes is one of the small handful of strips to capture what made Calvin and Hobbes great; I recommend giving it a try.)
Bill Amend’s FoxTrot Classics reprint for the 6th mentions that Peter has a mathematics test scheduled, and shows part of his preparation.
Charles Schulz’s Peanuts Begins for the 5th sees Charlie Brown working problems on the board. He’s stuck for what to do until he recasts the problem as scoring in football and golf. We may giggle at this, but I support his method. It’s convinced him the questions are worth solving, the most important thing to doing them at all. And it’s gotten him to the correct answers. Casting these questions as sports problems is the building of falsework: it helps one do the task, and then is taken away (or hidden) from the final product. Everyone who does mathematics builds some falsework like this. If we do a particular problem, or kind of problem, often enough we get comfortable enough with the main work that we don’t need the falsework anymore. So it is likely to be for Charlie Brown.
On the 8th is another strip of Charlie Brown doing arithmetic in class. Here he just makes a mistake from having counted in a funny way all morning. This, too, happens to us all.
I will have more Reading the Comics posts at this link, hopefully this week. Incidentally other essays mentioning Agnes are at this link, and essays mentioning FoxTrot, reruns or the new-run Sundays, are here. Thanks for reading.
## Reading the Comics, October 12, 2019: More Glances Edition
Today, I’m just listing the comics from last week that mentioned mathematics, but which didn’t raise a deep enough topic to be worth discussing. You know what a story problem looks like. I can’t keep adding to that.
John Zakour and Scott Roberts’s Maria’s Day for the 7th has Bob motivated to do arithmetic a little wrong.
Tony Carrillo’s F Minus for the 8th puts forth the idea that mathematics can be a superpower. Which, you know, it could be, given half a chance. According to a 1981 promotional comic book that Radio Shack carried, Superman’s brain is exactly as capable as a TRS-80 Color Computer. This was the pre-Crisis Superman, I feel like I should point out.
John Hambrock’s The Brilliant Mind of Edison Lee for the 9th has an appearance by $E = mc^2$.
Anthony Smith’s Learn to Speak Cat for the 9th is dubbed “Mathecatics” and uses a couple mathematical symbols to make a little cat cartoon.
Hector D. Cantú and Carlos Castellanos’s Baldo for the 10th quotes René Descartes, billing him as a “French mathematician”. Which is true, but the quote is one about living properly. That’s more fairly a philosophical matter. Descartes has some reputation for his philosophical work, I understand.
Bil Keane and Jeff Keane’s The Family Circus for the 11th drew quite a few merry comments in the snark-reading community since it’s a surprisingly wicked joke. It’s about Billy, Age 7, having trouble with an assignment that’s clearly arithmetic. So, enjoy.
Tony Cochran’s Agnes for the 11th has the title character declare her disinterest in mathematics on the grounds she won’t use it.
Patrick Roberts’s Todd the Dinosaur for the 12th has the title character struggling with fractions.
And that’s the last of last week’s mathematically-themed comic strips. I do plan to have the next Reading the Comics post on Sunday. Tomorrow should resume the Fall 2019 A-to-Z sequence with the letter ‘N’. And I am still open for topics for the next half-dozen essays. Please offer your thoughts; they’re all grand to receive. Thank you.
## Reading the Comics, June 1, 2019: More Than I Thought Edition
When I collected last week’s mathematically-themed comic strips I thought this set an uninspiring one. That changed sometime while I wrote. That’s the sort of week I like to have.
Richard Thompson’s Richard’s Poor Almanac for the 28th is a repeat; all these strips are. And I’ve featured it here before too. But never before in color, so I’ll take this chance to show it one last time. One of the depicted plants is the “Non-Euclidean Creeper”, which “ignores the geometry of the space-time continuum”. Non-Euclidean is one of those few geometry-related words that people recognize — maybe even only learn — in their adulthood. It has connotations of the bizarre and the weird and the wrong.
And it is a bit weird. While we live in a non-Euclidean space, we never really notice. Euclidean space is the geometry we’re used to from drawing shapes on paper and putting boxes in the corners of basements. And from this we’ve given “non-Euclidean” this sinister reputation. We credit it with defying common sense and even logic itself, although it’s geometry. It can’t defy logic. It can defy intuition. Non-Euclidean geometries have the idea that there are no such things as parallel lines. Or the idea that there are too many parallel lines. And it can get to weird results, particularly if we look at more than three dimensions of space. Those also tax the imagination. It will get a weed a bad reputation.
Chen Weng’s Messycow Comics for the 30th is about a child’s delight in learning how to count. I don’t remember ever being so fascinated by counting that it would distract me permanently. I do remember thinking it was amazing that once a pattern was established it kept on, with no reason to ever stop, or even change. My recollection is I thought this somehow unfair to the alphabet, which had a very sudden sharp end.
The counting numbers — counting in general — seem to be things we’ve evolved to understand. Other animals know how to count. Here I recommend again Stanislas Dehaene’s The Number Sense: How the Mind Creates Mathematics, which describes some of the things we know about how animals do mathematics. It also describes how children come to understand it.
Samson’s Dark Side of the Horse for the 31st is a bit of play with arithmetic. Horace simplifies his problem by catching all the numerals with loops in them — the zeroes and the eights — and working with what’s left. Evidently he’s already cast out all the nines. (This is me making a joke. Casting out nines is a simple checksum that you can do which can guard against some common arithmetic mistakes. It doesn’t catch everything. But it is simple enough to do that it can be worth using.)
The part that disappoints me is that to load the problem up with digits with loops, we get a problem that’s not actually hard: 100 times anything is easy. If the problem were, say, 189 times 80008005 then you’d have a problem someone might sensibly refuse to do. But without those zeroes at the start it’d be harder to understand what Horace was doing. Maybe if it were 10089 times 800805 instead.
Hilary Price and Rina Piccolo’s Rhymes with Orange for the 1st is the anthropomorphic numerals joke for the week. Also the anthropomorphic letters joke. The capital B sees occasional use in mathematics. It can represent the ball, that is, the set of all points that represent the interior of a sphere of a set radius. Usually a radius of 1. It also sometimes appears in equations as a parameter, a number whose value is fixed for the length of the problem but whose value we don’t care about. I had thought there were a few other roles for B alone, such as a label to represent the Bessel functions. These are a family of complicated-looking polynomials with some nice properties it’s too great a diversion for me to discuss just now. But they seem to more often be labelled with a capital J for reasons that probably seemed compelling at the time. It’ll also get used in logic, where B might stand for the second statement of some argument. 4, meanwhile, is that old familiar thing.
And there were a couple of comics which I like, but which mentioned mathematics so slightly that I couldn’t put a paragraph into them. Henry Scarpelli and Craig Boldman’s Archie rerun for the 27th, for example, mentions mathematics class as one it’s easy to sleep through. And Tony Cochrane’s Agnes for the 28th also mentions mathematics class, this time as one it’s hard to pay attention to.
This clears out last week’s comic strips. This present week’s strips should be at this link on Sunday. I haven’t yet read Friday or Saturday’s comics, so perhaps there’s been a flood, but this has been a slow week so far.
## Reading the Comics, April 5, 2019: The Slow Week Edition
People reading my Reading the Comics post Sunday maybe noticed something. I mean besides my correct, reasonable complaining about the Comics Kingdom redesign. That is that all the comics were from before the 30th of March. That is, none were from the week before the 7th of April. The last full week of March had a lot of comic strips. The first week of April didn’t. So things got bumped a little. Here’s the results. It wasn’t a busy week, not when I filter out the strips that don’t offer much to write about. So now I’m stuck for what to post Thursday.
Jason Poland’s Robbie and Bobby for the 3rd is a Library of Babel comic strip. This is mathematical enough for me. Jorge Luis Borges’s Library is a magnificent representation of some ideas about infinity and probability. I’m surprised to realize I haven’t written an essay specifically about it. I have touched on it, in writing about normal numbers, and about the infinite monkey theorem.
The strip explains things well enough. The Library holds every book that will ever be written. In the original story there are some constraints. Particularly, all the books are 410 pages. If you wanted, say, a 600-page book, though, you could find one book with the first 410 pages and another book with the remaining 190 pages and then some filler. The catch, as explained in the story and in the comic strip, is finding them. And there is the problem of finding a ‘correct’ text. Every possible text of the correct length should be in there. So every possible book that might be titled Mark Twain vs Frankenstein, including ones that include neither Mark Twain nor Frankenstein, is there. Which is the one you want to read?
Henry Scarpelli and Craig Boldman’s Archie for the 4th features an equal-divisions problem. In principle, it’s easy to divide a pizza (or anything else) equally; that’s what we have fractions for. Making them practical is a bit harder. I do like Jughead’s quick work, though. It’s got the slight-of-hand you expect from stage magic.
Scott Hilburn’s The Argyle Sweater for the 4th takes place in an algebra class. I’m not sure what algebraic principle $7^4 \times 13^6$ demonstrates, but it probably came from somewhere. It’s 4,829,210. The exponentials on the blackboard do cue the reader to the real joke, of the sign reading “kick10 me”. I question whether this is really an exponential kicking situation. It seems more like a simple multiplication to me. But it would be harder to make that joke read clearly.
Tony Cochran’s Agnes for the 5th is part of a sequence investigating how magnets work. Agnes and Trout find just … magnet parts inside. This is fair. It’s even mathematics.
Thermodynamics classes teach one of the great mathematical physics models. This is about what makes magnets. Magnets are made of … smaller magnets. This seems like question-begging. Ultimately you get down to individual molecules, each of which is very slightly magnetic. When small magnets are lined up in the right way, they can become a strong magnet. When they’re lined up in another way, they can be a weak magnet. Or no magnet at all.
How do they line up? It depends on things, including how the big magnet is made, and how it’s treated. A bit of energy can free molecules to line up, making a stronger magnet out of a weak one. Or it can break up the alignments, turning a strong magnet into a weak one. I’ve had physics instructors explain that you could, in principle, take an iron rod and magnetize it just by hitting it hard enough on the desk. And then demagnetize it by hitting it again. I have never seen one do this, though.
This is more than just a physics model. The mathematics of it is … well, it can be easy enough. A one-dimensional, nearest-neighbor model, lets us describe how materials might turn into magnets or break apart, depending on their temperature. Two- or three-dimensional models, or models that have each small magnet affected by distant neighbors, are harder.
And then there’s the comic strips that didn’t offer much to write about.
Brian Basset’s Red and Rover for the 3rd,
Liniers’s Macanudo for the 5th, Stephen Bentley’s Herb and Jamaal rerun for the 5th, and Gordon Bess’s Redeye rerun for the 5th all idly mention mathematics class, or things brought up in class.
Doug Savage’s Savage Chickens for the 2nd is another more-than-100-percent strip. Richard Thompson’s Richard’s Poor Almanac for the 3rd is a reprint of his Christmas Tree guide including a fir that “no longer inhabits Euclidean space”.
Mike Baldwin’s Cornered for the 31st depicts a common idiom about numbers. Eric the Circle for the 5th, by Rafoliveira, plays on the ∞ symbol.
And that covers the mathematically-themed comic strips from last week. There are more coming, though. I’ll show them on Sunday. Thanks for reading.
## Reading the Comics, January 12, 2019: A Edition
As I said Sunday, last week was a slow one for mathematically-themed comic strips. Here’s the second half of them. They’re not tightly on point. But that’s all right. They all have titles starting with ‘A’. I mean if you ignore the article ‘the’, the way we usually do when alphabetizing titles.
Tony Cochran’s Agnes for the 11th is basically a name-drop of mathematics. The joke would be unchanged if the teacher asked Agnes to circle all the adjectives in a sentence, or something like that. But there are historically links between religious thinking and mathematics. The Pythagoreans, for example, always a great and incredible starting point for any mathematical topic or just some preposterous jokes that might have nothing to do with their reality, were at least as much a religious and philosophical cult. For a long while in the Western tradition, the people with the time and training to do advanced mathematics work were often working for the church. Even as people were more able to specialize, a mystic streak remained. It’s easy to understand why. Mathematics promises to speak about things that are universally true. It encourages thinking about the infinite. It encourages thinking about the infinitely tiny. It courts paradoxes as difficult as any religious Mystery. It’s easy to snark at someone who takes numerology seriously. But I’m not sure the impulse that sees magic in arithmetic is different to the one that sees something supernatural in a “transfinite” item.
Scott Hilburn’s The Argyle Sweater for the 11th is another mistimed Pi Day joke. π is, famously, an irrational number. But so is every number, except for a handful of strange ones that we’ve happened to find interesting. That π should go on and on follows from what an irrational number means. It’s a bit surprising the 4 didn’t know all this before they married.
I appreciate the secondary joke that the marriage counselor is a “Hugh Jripov”, and the counselor’s being a ripoff is signaled by being a ÷ sign. It suggests that maybe successful reconciliation isn’t an option. I’m curious why the letters ‘POV’ are doubled, in the diploma there. In a strip with tighter drafting I’d think it was suggesting the way a glass frame will distort an image. But Hilburn draws much more loosely than that. I don’t know if it means anything.
Mark Anderson’s Andertoons for the 12th is the Mark Anderson’s Andertoons for the essay. I’m so relieved to have a regular stream of these again. The teacher thinks Wavehead doesn’t need to annotate his work. And maybe so. But writing down thoughts about a problem is often good practice. If you don’t know what to do, or you aren’t sure how to do what you want? Absolutely write down notes. List the things you’d want to do. Or things you’d want to know. Ways you could check your answer. Ways that you might work similar problems. Easier problems that resemble the one you want to do. You find answers by thinking about what you know, and the implications of what you know. Writing these thoughts out encourages you to find interesting true things.
And this was too marginal a mention of mathematics even for me, even on a slow week. But Georgia Dunn’s Breaking Cat News for the 12th has a cat having a nightmare about mathematics class. And it’s a fun comic strip that I’d like people to notice more.
And that’s as many comics as I have to talk about from last week. Sunday, I should have another Reading the Comics post and it’ll be at this link.
## Reading the Comics, January 1, 2019: New Year’s Day Edition
It’s a new year. That doesn’t mean I’m not going to keep up some of my old habits. One of them is reading the comics for the mathematics bits. For example …
Johnny Hart’s Back To BC for the 30th presents some curious use of mathematics. At least the grammar of mathematics. It’s a bunch of statements that are supposed to, taken together, overload … I’m going to say BC’s … brain. (I’m shaky on which of the characters is Peter and which is BC. Their difference in hair isn’t much of a visual hook.) Certainly mathematics inspires that feeling that one’s overloaded one’s brain. The long strings of reasoning and (ideally) precise definitions are hard to consider. And the proofs mathematicians find the most fun are, often, built cleverly. That is, going about their business demonstrating things that don’t seem relevant, and at the end tying them together. It’s hard to think.
But then … Peter … isn’t giving a real mathematical argument. He’s giving nonsense. And obvious nonsense, rather than nonsense because the writer wanted something that sounded complicated without caring what was said. Talking about a “four-sided triangle” or a “rectangular circle” has to be Peter trying to mess with BC’s head. Confidently-spoken nonsense can sound as if it’s deeper wisdom than the listener has. Which, fair enough: how can you tell whether an argument is nonsense or just cleverer than you are? Consider the kind of mathematics proof I mentioned above, where the structure might almost be a shaggy dog joke. If you can’t follow the logic, is it because the argument is wrong or because you haven’t worked out why it is right?
I believe that … Peter … is just giving nonsense and trusting that … BC … won’t know the difference, but will wear himself out trying to understand. Pranks.
Tim Lachowski’s Get A Life for the 31st just has some talk about percentages and depreciation and such. It’s meant to be funny that we might think of a brain depreciating, as if anatomy could use the same language as finance. Still, one of the virtues of statistics is the ability to understand a complicated reality with some manageable set of numbers. If we accept the convention that some number can represent the value of a business, why not the convention that some number could represent the health of a brain? So, it’s silly, but I can imagine a non-silly framing for it.
Tony Cochran’s Agnes for the 1st is about calendars. The history of calendars is tied up with mathematics in deep and sometimes peculiar ways. One might imagine that a simple ever-increasing index from some convenient reference starting time would do. And somehow that doesn’t. Also, the deeper you go into calendars the more you wonder if anyone involved in the project knew how to count. If you ever need to feel your head snapping, try following closely just how the ancient Roman calendar worked. Especially from the era when they would occasionally just drop an extra month in to the late-middle of February.
The Julian and Gregorian calendars have a year number that got assigned proleptically, that is, with the year 1 given to a set of dates that nobody present at the time called the year 1. Which seems fair enough; not many people in the year 1 had any idea that something noteworthy was under way. Calendar epochs dated to more clear events, like the reign of a new emperor or the revolution that took care of that whole emperor problem, will more reliably start with people aware of the new numbers. Proleptic dating has some neat side effects, though. If you ever need to not impress someone, you can point out that the dates from the 1st of March, 200 to the 28th of February, 300 both the Julian and the Gregorian calendar dates exactly matched.
Niklas Eriksson’s Carpe Diem for the 2nd is a dad joke about mathematics. And uses fractions as emblematic of mathematics, fairly enough. Introducing them and working with them are the sorts of thing that frustrate and confuse. I notice also the appearance of “37” here. Christopher Miller’s fascinating American Cornball: A Laffopedic Guide to the Formerly Funny identifies 37 as the current “funniest number”, displacing the early 20th century’s preferred 23 (as in skidoo). Among other things, odd numbers have a connotation of seeming more random than even numbers; ask someone to pick a whole number from 1 to 50 and you’ll see 37’s and 33’s more than you’ll see, oh, 48’s. Why? Good question. It’s among the mysteries of psychology. There’s likely no really deep reason. Maybe a sense that odd numbers are, well, odd as in peculiar, and that a bunch of peculiarities will be funny. Now let’s watch the next decade make a food of me and decide the funniest number is 64.
I’m glad to be back on schedule publishing Reading the Comics posts. I should have another one this week. It’ll be at this link when it’s ready. Thanks for reading.
## Reading the Comics, September 22, 2018: Last Chance Edition
I plan tomorrow to have another of my Mathematics A To Z posts. This weekend I’ll publish this month’s Playful Mathematics Blog Carnival. So if you’ve seen any web site, blog, video, podcast, or other reference that had something that delighted and taught you something, this is your last chance to let me know, and let my audience know about it. Please leave a comment if you know about anything I ought to see. Thank you.
Mark Tatulli’s Lio for the 20th is a numerals and a wordplay joke. It is not hard to make numerals tattooed on a person an alarming thing. But when done with (I trust) the person’s consent, and done whimsically like this, it’s more a slightly odd bit of play.
Tony Cochrane’s Agnes for the 21st is ultimately a strip about motivating someone to learn arithmetic. Agnes’s reasoning is sound, though. If the only reason to learn this unpleasant chore is because your job may need it, why not look at another job? We wouldn’t try to convince someone who didn’t want to learn French that they’ll need it for their job as … a tour guide in Quebec? There’s plenty of work that doesn’t need that. I suspect kids don’t buy “this is good for your future job” as a reason. Even if it were, general education should not be job training either.
Juba’s Viivi and Wagner for the 21st gives Wagner a short-lived ambition to be a wandering mathematician. The abacus serves as badge of office. There are times and places that his ambition wouldn’t be completely absurd. Before the advent of electric and electronic computing, people who could calculate were worth hiring for their arithmetic. In 18th Century London there was a culture of “penny universities”, people with academic training making a living by giving lectures and courses to whatever members of the public cared to come to their talk, often in coffee-houses or barns.
Mathematicians learn that there used to be public spectacles, mathematicians challenging one another to do problems, with real cash or jobs on the line. They learn this because one such challenge figures in to the story of Gerolamo Cardano and Niccolò Fontana, known as Tartaglia. It’s about how we learned formulas to solve some kinds of polynomials. You may sense uncertainty in my claim there. It’s because it turns out it’s hard to find clear records of this sort of challenge outside the Cardano-Tartaglia match. That isn’t to say these things weren’t common. It’s just that I’ve been slowly learning to be careful about my claims.
(I’m aided here by a startling pair of episodes of The History of Philosophy Without Any Gaps podcast. This pair — “Trivial Pursuits: Fourteenth Century Logic” and “Sara Uckleman on Obligations” — describe a fascinating logic game that sounds like it would still be a great party game, for which there’s numerous commentaries and rule sets and descriptions of how to play. But no records of people actually ever playing it, or talking about games they had played, or complaining about being cheated out of a win or stuff like that. It’s a strong reminder to look closely at what your evidence does support.)
Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 22nd is the comforting return of Zach Weinersmith to these essays. And yes, it’s horrible parenting to promise something fun and have it turn out to be a mathematics lecture, but that’s part of the joke.
Karl Weierstrass was a real person, and a great mathematician best known for giving us a good, rigorous idea of what a limit is. We need limits because, besides their being nice things to have, calculus depends on them. At least, calculus depends on thinking about calculations on infinitely many things. Or on things infinitesimally small. Trying to do this works pretty well, much of the time. But you can also start calculating like this and get nonsense. How to tell whether your particular calculation works out or is nonsense?
Weierstrass worked out a good, rigorous idea for what we mean by a limit. It mostly tracks with what we’d intuitively expect. And it avoids all the dangerous spots we’ve noticed so far. Particularly, it doesn’t require us to ever look at anything that’s infinitely vast, or infinitesimally small. Anything we calculate on is done with regular arithmetic, that we’re quite confident in. But it lets us draw conclusions about the infinitely numerous or tiny. It’s brilliant work. When it’s presented to someone in the start of calculus, it leaves them completely baffled but they can maybe follow along with the rules. When it’s presented to mathematics majors in real analysis, it leaves them largely baffled but they can maybe follow along with the reasons. Somewhere around grad school I got comfortable with it, even excited. Weierstrass’s sort of definition turns up all over the place in real and in functional analysis. So at the least you get very comfortable with it.
So it is part of Weinersmith’s joke that this is way above that kid’s class level. As a joke, that fails for me. The luchador might as well be talking complete nonsense and the kid would realize that right away. There’s not the threat that this is something he ought to be able to understand. But it will probably always be funny to imagine mathematician wrestlers. Can count on that. I didn’t mean that as a joke, but you’ll notice I’m letting it stand.
And with that, you know what I figure to post on Sunday. It and my other Reading the Comics posts should be at this tag. Other appearances of Lio should be at this link. The mentions of Agnes should be at this link. Essays with some mention of Viivi and Wagner will be at this link, although it’s a new tag, so who knows how long it’ll take for the next to appear? And other essays with Saturday Morning Breakfast Cereal will be at this link when there’s any to mention.
## Reading the Comics, March 31, 2018: A Normal Week Edition
I have a couple loose rules about these Reading the Comics posts. At least one a week, whether there’s much to talk about or not. Not too many comics in one post, because that’s tiring to read and tiring to write. Trying to write up each day’s comics on the day mitigates that some, but not completely. So I tend to break up a week’s material if I can do, say, two posts of about seven strips each. This year, that’s been necessary; I’ve had a flood of comics on-topic or close enough for me to write about. This past week was a bizarre case. There really weren’t enough strips to break up the workload. It was, in short, a normal week, as strange as that is to see. I don’t know what I’m going to do Thursday. I might have to work.
Aaron McGruder’s Boondocks for the 25th of March is formally just a cameo mention of mathematics. There is some serious content to it. Whether someone likes to do a thing depends, to an extent, on whether they expect to like doing a thing. It seems likely to me that if a community encourages people to do mathematics, then it’ll have more people who do mathematics well. Mathematics does at least have the advantage that a lot of its fields can be turned into games. Or into things like games. Is one knot the same as another knot? You can test the laborious but inevitably correct way, trying to turn one into the other. Or you can find a polynomial that describes both knots and see if those two are the same polynomials. There’s fun to be had in this. I swear. And, of course, making arguments and finding flaws in other people’s arguments is a lot of mathematics. And good fun for anybody who likes that sort of thing. (This is a new tag for me.)
Ted Shearer’s Quincy for the 30th of January, 1979 and rerun the 26th names arithmetic as the homework Quincy’s most worried about. Or would like to put off the most. Harmless enough.
Mike Thompson’s Grand Avenue for the 26th is a student-resisting-the-problem joke. A variable like ‘x’ serves a couple of roles. One of them is the name for a number whose value we don’t explicitly know, but which we hope to work out. And that’s the ‘x’ seen here. The other role of ‘x’ is the name for a number whose value we don’t know and don’t particularly care about. Since those are different reasons to use ‘x’ maybe we ought to have different names for the concepts. But we don’t and there’s probably no separating them now.
Tony Cochran’s Agnes for the 27th grumbles that mathematics and clairvoyance are poorly taught. Well, everyone who loves mathematics grumbles that the subject is poorly taught. I don’t know what the clairvoyants think but I’ll bet the same.
Mark Pett’s Lucky Cow rerun for the 28th is about sudoku. As with any puzzle the challenge is having rules that are restrictive enough to be interesting. This is also true of any mathematical field, though. You want ideas that imply a lot of things are true, but that also imply enough interesting plausible things are not true.
Rick DeTorie’s One Big Happy rerun for the 30th has Ruthie working on a story problem. One with loose change, which seems to turn up a lot in story problems. I never think of antes for some reason.
Stephen Beals’s Adult Children for the 31st depicts mathematics as the stuff of nightmares. (Although it’s not clear to me this is meant to recount a nightmare. Reads like it, anyway.) Calculus, too, which is an interesting choice. Calculus seems to be a breaking point for many people. A lot of people even who were good at algebra or trigonometry find all this talk about differentials and integrals and limits won’t cohere into understanding. Isaac Asimov wrote about this several times, and the sad realization that for as much as he loved mathematics there were big important parts of it that he could not comprehend.
I’m curious why calculus should be such a discontinuity, but the reasons are probably straightforward. It’s a field where you’re less interested in doing things to numbers and more interested in doing things to functions. Or to curves that a function might represent. It’s a field where information about a whole region is important, rather than information about a single point. It’s a field where you can test your intuitive feeling for, say, a limit by calculating a couple of values, but for which those calculations don’t give the right answer. Or at least can’t be guaranteed to be right. I don’t know if the choice of what to represent mathematics was arbitrary. But it was a good choice certainly. (This is another newly-tagged strip.)
## Reading the Comics, February 17, 2018: Continuing Deluge Month
February’s been a flooding month. Literally (we’re about two blocks away from the Voluntary Evacuation Zone after the rains earlier this week) and figuratively, in Comic Strip Master Command’s suggestions about what I might write. I have started thinking about making a little list of the comics that just say mathematics in some capacity but don’t give me much to talk about. (For example, Bob the Squirrel having a sequence, as it does this week, with a geometry tutor.) But I also know, this is unusually busy this month. The problem will recede without my having to fix anything. One of life’s secrets is learning how to tell when a problem’s that kind.
Patrick Roberts’s Todd the Dinosaur for the 12th just shows off an arithmetic problem — fractions — as the thing that can be put on the board and left for students to do.
Ham’s Life on Earth for the 12th has a science-y type giving a formula as “something you should know”. The formula’s gibberish, so don’t worry about it. I got a vibe of it intending to be some formula from statistics, but there’s no good reason for that. I’ve had some statistical distribution problems on my mind lately.
Eric Teitelbaum and Bill Teitelbaum’s Bottomliners for the 12th maybe influenced my thinking. It has a person claiming to be a former statistician, and his estimate of how changing his job’s affected his happiness. Could really be any job that encourages people to measure and quantify things. But “statistician” is a job with strong connotations of being able to quantify happiness. To have that quantity feature a decimal point, too, makes him sound more mathematical and thus, more surely correct. I’d be surprised if “two and a half times” weren’t a more justifiable estimate, given the margin for error on happiness-measurement I have to imagine would be there. (This seems to be the first time I’ve featured Bottomliners at least since I started tagging the comic strips named. Neat.)
Ruben Bolling’s Super-Fun-Pak Comix for the 12th reprinted a panel called The Uncertainty Principal that baffled commenters there. It’s a pun on “Uncertainty Principle”, the surprising quantum mechanics result that there are some kinds of measurements that can’t be taken together with perfect precision. To know precisely where something is destroys one’s ability to measure its momentum. To know the angular momentum along one axis destroys one’s ability to measure it along another. This is a physics result (note that the panel’s signed “Heisenberg”, for the name famously attached to the Uncertainty Principle). But the effect has a mathematical side. The operations that describe finding these incompatible pairs of things are noncommutative; it depends what order you do them in.
We’re familiar enough with noncommutative operations in the real world: to cut a piece of paper and then fold it usually gives something different to folding a piece of paper and then cutting it. To pour batter in a bowl and then put it in the oven has a different outcome than putting batter in the oven and then trying to pour it into the bowl. Nice ordinary familiar mathematics that people learn, like addition and multiplication, do commute. These come with partners that don’t commute, subtraction and division. But I get the sense we don’t think of subtraction and division like that. It’s plain enough that ‘a’ divided by ‘b’ and ‘b’ divided by ‘a’ are such different things that we don’t consider what’s neat about that.
In the ordinary world the Uncertainty Principle’s almost impossible to detect; I’m not sure there’s any macroscopic phenomena that show it off. I mean, that atoms don’t collapse into electrically neutral points within nanoseconds, sure, but that isn’t as compelling as, like, something with a sodium lamp and a diffraction grating and an interference pattern on the wall. The limits of describing certain pairs of properties is about how precisely both quantities can be known, together. For everyday purposes there’s enough uncertainty about, say, the principal’s weight (and thus momentum) that uncertainty in his position won’t be noticeable. There’s reasons it took so long for anyone to suspect this thing existed.
Samson’s Dark Side of the Horse for the 13th uses a spot of arithmetic as the sort of problem coffee helps Horace solve. The answer’s 1.
Mike Baldwin’s Cornered for the 14th is a blackboard-full-of-symbols panel. Well, a whiteboard. It’s another in the line of mathematical proofs of love.
Dana Simpson’s Ozy and Millie rerun for the 14th has the title characters playing “logical fallacy tag”. Ozy is, as Millie says, making an induction argument. In a proper induction argument, you characterize something with some measure of size. Often this is literally a number. You then show that if it’s true that the thing is true for smaller problems than you’re interested in, then it has to also be true for the problem you are interested in. Add to that a proof that it’s true for some small enough problem and you’re done. In this case, Ozy’s specific fallacy is an appeal to probability: all but one of the people playing tag are not it, and therefore, any particular person playing the game isn’t it. That it’s fallacious really stands out when there’s only two people playing.
Alex Hallatt’s Arctic Circle for the 16th riffs on the mathematics abilities of birds. Pigeons, in this case. The strip starts from their abilities understanding space and time (which are amazing) and proposes pigeons have some insight into the Grand Unified Theory. Animals have got astounding mathematical abilities, should point out. Don’t underestimate them. (This also seems to be the first time I’ve tagged Arctic Circle which doesn’t seem like it could be right. But I didn’t remember naming the penguins before so maybe I haven’t? Huh. Mind, I only started tagging the comic strip titles a couple months ago.)
Tony Cochrane’s Agnes for the 17th has the title character try bluffing her way out of mathematics homework. Could there be a fundamental flaw in mathematics as we know it? Possibly. It’s hard to prove that any field complicated enough to be interesting is also self-consistent. And there’s a lot of mathematics out there. And mathematics subjects often develop with an explosion of new ideas and then a later generation that cleans them up and fills in logical gaps. Symplectic geometry is, if I’m following the news right, going into one of those cleaning-up phases now. Is it likely to be uncovered by a girl in elementary school? I’m skeptical, and also skeptical that she’d have a replacement system that would be any better. I admire Agnes’s ambition, though.
Mike Baldwin’s Cornered for the 17th plays on the reputation for quantum mechanics as a bunch of mathematically weird, counter-intuitive results. In fairness to the TV program, I’ve had series run longer than I originally planned too.
I thought my new workflow of writing my paragraph or two about each comic was going to help me keep up and keep fresher with the daily comics. And then Comic Strip Master Command decided that everybody had to do comics that at least touched on some mathematical subject. I don’t know. I’m trying to keep up but will admit, I didn’t get to writing anything about Friday’s or Saturday’s strips yet. They’ll keep a couple days.
Bill Amend’s FoxTrot Classicsfor the 29th of January reprints the strip from the 5th of February, 1996. (The Classics reprints finally reached the point where Amend retired from daily strips, and jumped back a dozen years to continue printing.) It just mentions mathematics exams, and high performances on both is all.
Josh Shalek’s Kid Shay Comics reprint for the 29th tosses off a mention of Uncle Brian attempting a great mathematical feat. In this case it’s the Grand Unification Theory, some logically coherent set of equations that describe the fundamental forces of the universe. I think anyone with a love for mathematics makes a couple quixotic attempts on enormously vast problems like this. Or the Riemann Hypothesis, or Goldbach’s Conjecture, or Fermat’s Last Theorem. Yes, Fermat’s Last Theorem has been proven, but there’s no reason there couldn’t be an easier proof. Similarly there’s no reason there couldn’t be a better proof of the Four Color Map theorem. Most of these attempts end up the way Brian’s did. But there’s value in attempting this anyway. Even when you fail, you can have fun and learn fascinating things in the attempt.
Carol Lay’s Lay Lines for the 29th is a vignette about a statistician. And one of those statisticians with the job of finding surprising correlations between things. I think it’s also a riff on the hypothesis that free markets are necessarily perfect: if there’s any advantage to doing something one way, it’ll quickly be found and copied until that is the normal performance of the market. Anyone doing better than average is either taking advantage of concealed information, or else is lucky.
Matt Lubchansky’s Please Listen To Me for the 29th depicts a person doing statistical work for his own purposes. In this case he’s trying to find what factors might be screwing up the world. The expressions in the second panel don’t have an obvious meaning to me. The start of the expression $\int exp\left(\frac{1}{N_0}\right)$ at the top line suggests statistical mechanics to me, for what that’s worth, and the H and Ψ underneath suggest thermodynamics or quantum mechanics. So if Lubchansky was just making up stuff, he was doing it with a good eye for mathematics that might underly everything.
Rick Stromoski’s Soup to Nutz for the 29th circles around the anthropomorphic numerals idea. It’s not there exactly, but Andrew is spending some time giving personality to numerals. I can’t say I give numbers this much character. But there are numbers that seem nicer than others. Usually this relates to what I can do with the numbers. 10, for example, is so easy to multiply or divide by. If I need to multiply a number by, say, something near thirty, it’s a delight to triple it and then multiply by ten. Twelve and 24 and 60 are fun because they’re so relatively easy to find parts of. Even numbers often do seem easier to work with, just because splitting an even number in half saves us from dealing with decimals or fractions. Royboy sees all this as silliness, which seems out of character for him, really. I’d expect him to be up for assigning traits to numbers like that.
Bill Griffith’s Zippy the Pinhead for the 30th mentions Albert Einstein and relativity. And Zippy ruminates on the idea that there’s duplicates of everything, in the vastness of the universe. It’s an unsettling idea that isn’t obviously ruled out by mathematics alone. There’s, presumably, some chance that a bunch of carbon and hydrogen and oxygen and other atoms happened to come together in such a way as to make our world as we know it today. If there’s a vast enough universe, isn’t there a chance that a bunch of carbon and hydrogen and oxygen and other atoms happened to come together that same way twice? Three times? If the universe is infinitely large, might it not happen infinitely many times? In any number of variations? It’s hard to see why not, but even if it is possible, that’s no reason to think it must happen either. And whether those duplicates are us is a question for philosophers studying the problem of identity and what it means to be one person rather than some other person. (It turns out to be a very difficult problem and I’m glad I’m not expected to offer answers.)
Tony Cochrane’s Agnes attempts to use mathematics to reason her way to a better bedtime the 31st. She’s not doing well. Also this seems like it’s more of an optimization problem than a simple arithmetic one. What’s the latest bedtime she can get that still allows for everything that has to be done, likely including getting up in time and getting enough sleep? Also, just my experience but I didn’t think Agnes was old enough to stay up until 10 in the first place.
## Reading the Comics, October 2017: Mathematics Anxiety Edition
Comic Strip Master Command hasn’t had many comics exactly on mathematical points the past week. I’ll make do. There are some that are close enough for me, since I like the comics already. And enough of them circle around people being nervous about doing mathematics that I have a title for this edition.
Tony Cochrane’s Agnes for the 24th talks about math anxiety. It’s not a comic strip that will do anything to resolve anyone’s mathematics anxiety. But it’s funny about its business. Agnes usually is; it’s one of the less-appreciated deeply-bizarre comics out there.
John Atkinson’s Wrong Hands for the 24th might be the anthropomorphic numerals joke for this week. Or it might be the anthropomorphic letters joke. Or something else entirely.
Charles Schulz’s Peanuts for the 24th reruns the comic from the 2nd of November, 1970. It has Sally discovering that multiplication is much easier than she imagined. As it is, she’s not in good shape. But if you accept ‘tooty-two’ as another name for ‘four’ and ‘threety-three’ as another name for ‘nine’, why not? And she might do all right in group theory. In that you can select a bunch of things, called ‘elements’, and describe their multiplication to fit anything you like, provided there’s consistency. There could be a four-forty-four if that seems to answer some question.
Steve Kelley and Jeff Parker’s Dustin for the 25th might be tied in to mathematics anxiety. At least it expresses how the thought of mathematics will cause some people to shut down entirely. Shame for them, but I can’t deny it’s so.
Jason Poland’s Robbie and Bobby for the 26th is an anthropomorphic geometry joke. And it’s a shape joke I don’t remember seeing, at least not under my Reading the Comics line of jokes. (Maybe I’ve just forgotten). Also, trapezoids: my most popular post of all time ever, even though it’s only got a couple months’ lead on the other perennial favorite, about how many grooves are on a record’s side.
Jerry Scott and Jim Borgman’s Zits for the 27th uses mathematics as the emblem of complicated stuff in need of study. It’s a good visual. I have to say Jeremy’s material seems unorganized to start with, though.
## Reading the Comics, June 26, 2017: Deluge Edition, Part 1
So this past week saw a lot of comic strips with some mathematical connection put forth. There were enough just for the 26th that I probably could have done an essay with exclusively those comics. So it’s another split-week edition, which suits me fine as I need to balance some of my writing loads the next couple weeks for convenience (mine).
Tony Cochrane’s Agnes for the 25th of June is fun as the comic strip almost always is. And it’s even about estimation, one of the things mathematicians do way more than non-mathematicians expect. Mathematics has a reputation for precision, when in my experience it’s much more about understanding and controlling error methods. Even in analysis, the study of why calculus works, the typical proof amounts to showing that the difference between what you want to prove and what you can prove is smaller than your tolerance for an error. So: how do we go about estimating something difficult, like, the number of stars? If it’s true that nobody really knows, how do we know there are some wrong answers? And the underlying answer is that we always know some things, and those let us rule out answers that are obviously low or obviously high. We can make progress.
Russell Myers’s Broom Hilda for the 25th is about one explanation given for why time keeps seeming to pass faster as one age. This is a mathematical explanation, built on the idea that the same linear unit of time is a greater proportion of a young person’s lifestyle so of course it seems to take longer. This is probably partly true. Most of our senses work by a sense of proportion: it’s easy to tell a one-kilogram from a two-kilogram weight by holding them, and easy to tell a five-kilogram from a ten-kilogram weight, but harder to tell a five from a six-kilogram weight.
As ever, though, I’m skeptical that anything really is that simple. My biggest doubt is that it seems to me time flies when we haven’t got stories to tell about our days, when they’re all more or less the same. When we’re doing new or exciting or unusual things we remember more of the days and more about the days. A kid has an easy time finding new things, and exciting or unusual things. Broom Hilda, at something like 1500-plus years old and really a dour, unsociable person, doesn’t do so much that isn’t just like she’s done before. Wouldn’t that be an influence? And I doubt that’s a complete explanation either. Real things are more complicated than that yet.
Mac and Bill King’s Magic In A Minute for the 25th features a form-a-square puzzle using some triangles. Mathematics? Well, logic anyway. Also a good reminder about open-mindedness when you’re attempting to construct something.
Norm Feuti’s Retail for the 26th is about how you get good at arithmetic. I suspect there’s two natural paths; you either find it really interesting in your own right, or you do it often enough you want to find ways to do it quicker. Marla shows the signs of learning to do arithmetic quickly because she does it a lot: turning “30 percent off” into “subtract ten percent three times over” is definitely the easy way to go. The alternative is multiplying by seven and dividing by ten and you don’t want to multiply by seven unless the problem gives a good reason why you should. And I certainly don’t fault the customer not knowing offhand what 30 percent off \$25 would be. Why would she be in practice doing this sort of problem?
Johnny Hart’s Back To B.C. for the 26th reruns the comic from the 30th of December, 1959. In it … uh … one of the cavemen guys has found his calendar for the next year has too many days. (Think about what 1960 was.) It’s a common problem. Every calendar people have developed has too few or too many days, as the Earth’s daily rotations on its axis and annual revolution around the sun aren’t perfectly synchronized. We handle this in many different ways. Some calendars worry little about tracking solar time and just follow the moon. Some calendars would run deliberately short and leave a little stretch of un-named time before the new year started; the ancient Roman calendar, before the addition of February and January, is famous in calendar-enthusiast circles for this. We’ve now settled on a calendar which will let the nominal seasons and the actual seasons drift out of synch slowly enough that periodic changes in the Earth’s orbit will dominate the problem before the error between actual-year and calendar-year length will matter. That’s a pretty good sort of error control.
8,978,432 is not anywhere near the number of days that would be taken between 4,000 BC and the present day. It’s not a joke about Bishop Ussher’s famous research into the time it would take to fit all the Biblically recorded events into history. The time is something like 24,600 years ago, a choice which intrigues me. It would make fair sense to declare, what the heck, they lived 25,000 years ago and use that as the nominal date for the comic strip. 24,600 is a weird number of years. Since it doesn’t seem to be meaningful I suppose Hart went, simply enough, with a number that was funny just for being riotously large.
Mark Tatulli’s Heart of the City for the 26th places itself on my Grand Avenue warning board. There’s plenty of time for things to go a different way but right now it’s set up for a toxic little presentation of mathematics. Heart, after being grounded, was caught sneaking out to a slumber party and now her mother is sending her to two weeks of Math Camp. I’m supposing, from Tatulli’s general attitude about how stuff happens in Heart and in Lio that Math Camp will not be a horrible, penal experience. But it’s still ominous talk and I’m watching.
Brian Fies’s Mom’s Cancer story for the 26th is part of the strip’s rerun on GoComics. (Many comic strips that have ended their run go into eternal loops on GoComics.) This is one of the strips with mathematical content. The spatial dimension of a thing implies relationships between the volume (area, hypervolume, whatever) of a thing and its characteristic linear measure, its diameter or radius or side length. It can be disappointing.
Nicholas Gurewitch’s Perry Bible Fellowship for the 26th is a repeat of one I get on my mathematics Twitter friends now and then. Should warn, it’s kind of racy content, at least as far as my usual recommendations here go. It’s also a little baffling because while the reveal of the unclad woman is funny … what, exactly, does it mean? The symbols don’t mean anything; they’re just what fits graphically. I think the strip is getting at Dr Loring not being able to see even a woman presenting herself for sex as anything but mathematics. I guess that’s funny, but it seems like the idea isn’t quite fully developed.
Zach Weinersmith’s Saturday Morning Breakfast Cereal Again for the 26th has a mathematician snort about plotting a giraffe logarithmically. This is all about representations of figures. When we plot something we usually start with a linear graph: a couple of axes perpendicular to one another. A unit of movement in the direction of any of those axes represents a constant difference in whatever that axis measures. Something growing ten units larger, say. That’s fine for many purposes. But we may want to measure something that changes by a power law, or that grows (or shrinks) exponentially. Or something that has some region where it’s small and some region where it’s huge. Then we might switch to a logarithmic plot. Here the same difference in space along the axis represents a change that’s constant in proportion: something growing ten times as large, say. The effective result is to squash a shape down, making the higher points more nearly flat.
And to completely smother Weinersmith’s fine enough joke: I would call that plot semilogarithmically. I’d use a linear scale for the horizontal axis, the gazelle or giraffe head-to-tail. But I’d use a logarithmic scale for the vertical axis, ears-to-hooves. So, linear in one direction, logarithmic in the other. I’d be more inclined to use “logarithmic” plots to mean logarithms in both the horizontal and the vertical axes. Those are useful plots for turning up power laws, like the relationship between a planet’s orbital radius and the length of its year. Relationships like that turn into straight lines when both axes are logarithmically spaced. But I might also describe that as a “log-log plot” in the hopes of avoiding confusion.
## Reading the Comics, May 13, 2017: Quiet Tuesday Through Saturday Edition
From the Sunday and Monday comics pages I was expecting another banner week. And then there was just nothing from Tuesday on, at least not among the comic strips I read. Maybe Comic Strip Master Command has ordered jokes saved up for the last weeks before summer vacation.
Tony Cochrane’s Agnes for the 7th is a mathematics anxiety strip. It’s well-expressed, since Cochrane writes this sort of hyperbole well. It also shows a common attitude that words and stories are these warm, friendly things, while mathematics and numbers are cold and austere. Perhaps Agnes is right to say some of the problem is familiarity. It’s surely impossible to go a day without words, if you interact with people or their legacies; to go without numbers … well, properly impossible. There’s too many things that have to be counted. Or places where arithmetic sneaks in, such as getting enough money to buy a thing. But those don’t seem to be the kinds of mathematics people get anxious about. Figuring out how much change, that’s different.
I suppose some of it is familiarity. It’s easier to dislike stuff you don’t do often. The unfamiliar is frightening, or at least annoying. And humans are story-oriented. Even nonfiction forms stories well. Mathematics … has stories, as do all human projects. But the mathematics itself? I don’t know. There’s just beautiful ingenuity and imagination in a lot of it. I’d just been thinking of the just beautiful scheme for calculating logarithms from a short table. But it takes time to get to that beauty.
Gary Wise and Lance Aldrich’s Real Life Adventures for the 7th is a fractions joke. It might also be a joke about women concealing their ages. Or perhaps it’s about mathematicians expressing things in needlessly complicated ways. I think that’s less a mathematician’s trait than a common human trait. If you’re expert in a thing it’s hard to resist the puckish fun of showing that expertise off. Or just sowing confusion where one may.
Daniel Shelton’s Ben for the 8th is a kid-doing-arithmetic problem. Even I can’t squeeze some deeper subject meaning out of it, but it’s a slow week so I’ll include the strip anyway. Sorry.
Brian Boychuk and Ron Boychuk’s Chuckle Brothers for the 8th is the return of anthropomorphic-geometry joke after what feels like months without. I haven’t checked how long it’s been without but I’m assuming you’ll let me claim that. Thank you.
## Reading the Comics, February 6, 2017: Another Pictureless Half-Week Edition
Got another little flood of mathematically-themed comic strips last week and so once again I’ll split them along something that looks kind of middle-ish. Also this is another bunch of GoComics.com-only posts. Since those seem to be accessible to anyone whether or not they’re subscribers indefinitely far into the future I don’t feel like I can put the comics directly up and will trust you all to click on the links that you find interesting. Which is fine; the new GoComics.com design makes it annoyingly hard to download a comic strip. I don’t think that was their intention. But that’s one of the two nagging problems I have with their new design. So you know.
Tony Cochran’s Agnes for the 5th sees a brand-new mathematics. Always dangerous stuff. But mathematicians do invent, or discover, new things in mathematics all the time. Part of the task is naming the things in it. That’s something which takes talent. Some people, such as Leonhard Euler, had the knack a great novelist has for putting names to things. The rest of us muddle along. Often if there’s any real-world inspiration, or resemblance to anything, we’ll rely on that. And we look for terminology that evokes similar ideas in other fields. … And, Agnes would like to know, there is mathematics that’s about approximate answers, being “right around” the desired answer. Unfortunately, that’s hard. (It’s all hard, if you’re going to take it seriously, much like everything else people do.)
Scott Hilburn’s The Argyle Sweater for the 5th is the anthropomorphic numerals joke for this essay.
Carol Lay’s Lay Lines for the 6th depicts the hazards of thinking deeply and hard about the infinitely large and the infinitesimally small. They’re hard. Our intuition seems well-suited to handing a modest bunch of household-sized things. Logic guides us when thinking about the infinitely large or small, but it takes a long time to get truly conversant and comfortable with it all.
Paul Gilligan’s Pooch Cafe for the 6th sees Poncho try to argue there’s thermodynamical reasons for not being kind. Reasoning about why one should be kind (or not) is the business of philosophers and I won’t overstep my expertise. Poncho’s mathematics, that’s something I can write about. He argues “if you give something of yourself, you inherently have less”. That seems to be arguing for a global conservation of self-ness, that the thing can’t be created or lost, merely transferred around. That’s fair enough as a description of what the first law of thermodynamics tells us about energy. The equation he reads off reads, “the change in the internal energy (Δ U) equals the heat added to the system (U) minus the work done by the system (W)”. Conservation laws aren’t unique to thermodynamics. But Poncho may be aware of just how universal and powerful thermodynamics is. I’m open to an argument that it’s the most important field of physics.
Jonathan Lemon’s Rabbits Against Magic for the 6th is another strip Intro to Calculus instructors can use for their presentation on instantaneous versus average velocities. There’s been a bunch of them recently. I wonder if someone at Comic Strip Master Command got a speeding ticket.
Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 6th is about numeric bases. They’re fun to learn about. There’s an arbitrariness in the way we represent concepts. I think we can understand better what kinds of problems seem easy and what kinds seem harder if we write them out different ways. But base eleven is only good for jokes.
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https://www.ukessays.com/essays/chemistry/expiremnt-on-combustion-and-the-number-of-carbon-atoms-in-an-alcohol-chain.php
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# Expiremnt on Combustion and the Number of Carbon Atoms in an Alcohol Chain
11733 words (47 pages) Essay in Chemistry
08/02/20 Chemistry Reference this
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Chemical Fundamentals
Student Experiment: Molar Heat
Rationale
Alcohol can be burned as a source of energy instead of using fossil fuels. Smith and Workman [1] say that alcohol has been used as a fuel for the internal combustion engine since its invention. Reports on the use of alcohol as a motor fuel were published in 1907 and detailed research was conducted in the 1920s and 1930s (OCR, 2013).
Alcohols are organic compounds containing Oxygen, Hydrogen and Carbon. They are a family of
hydrocarbons that contain the –OH group. The alcohols are a homologous series containing the functional
–OH group, which determines the characteristic reactions of a compound.
The general formula of alcohols is CnH2n+1OH, where n is a number. Alcohols are also referred to as
alkanols. The simplest alcohol contains a single Carbon atom and is called Methanol. Its molecular
formula is CH3OH. As we move down the homologous series of alcohols, the number of Carbon atoms
increase. Each alcohol molecule differs by –CH2; a single Carbon atom and two Hydrogen atoms.
The figure below is the structural formula of Methanol (CH3OH) and Ethanol (C2H5OH) respectively:
Methanol Ethanol
(Pictures taken From: http://www.gcsescience.com/Methanol.gif and http://www.gcsescience.com/Ethanol.gif)
This table below shows the molecular formulas of the early members of the alcohol homologous series.
It can be seen as we go down the homologous series of alcohols, carbon atoms are added onto the
hydrocarbon chains. These chains are becoming longer and much more complex. Moreover, as we go
down the group, the alcohols’ boiling points, heat of combustions, and other characteristics show changes
as well.
Combustion is principally the oxidation of carbon compounds by oxygen in air to form CO2 if there is a
sufficient amount of oxygen. The hydrogen in a compound forms H2O. Combustion produces heat as
well as carbon dioxide and water. The enthalpy change of combustion is the enthalpy change that occurs
when 1 mole of a fuel is burned completely in oxygen.
(Taken from:
http://www.coursework.info/AS_and_A_Level/Chemistry/Organic_Chemistry/Find_the_enthalpy_chang
e_of_combustion_o_L61656.html#ixzz0fokacpwD)
The heat of combustion (standard enthalpy change of combustion) is the enthalpy change when one mole
of the compound undergoes complete combustion in excess oxygen under standard conditions. It is given
the symbol ∆H˚comb and standard conditions simply refer to room conditions with a temperature of 298K
and pressure of 1 atm.
As a result, the aim of the experiment is to determine whether there is a relationship between the number
of carbon atoms in an alcohol chain and its respective standard enthalpy change of combustion.
Original Experiment
Measure the mass of the empty spirit lamp using the electronic balance. Record the result in Table 1 below. Measure 30 mL of ethanol and pour it into the spirit lamp. Measure the mass of the spirit lamp containing the ethanol and record the result in Table 1. Measure 100 mL of distilled water (record the result in Table 1) and add it to the calorimeter. Insert the stirrer into the calorimeter and set up the thermometer so that the bulb of the thermometer is in the centre of the volume of water. Use the thermometer to record the initial temperature of the water (Ti). Cover the calorimeter with the lid and place it directly over the spirit lamp (Figure 1). Place safety mats around the spirit lamp to limit heat lost to the environment. Use a match to light the spirit lamp. Once the ethanol is burning, start the stopwatch. Record any change in the temperature of the water. Gently stir the water during the heating. Extinguish the spirit lamp and halt the stopwatch as soon as the temperature has risen 30°C. Record the final temperature of the water (Tf). Record the mass of the spirit lamp containing the remaining the ethanol.
Diagram 1 – The setup used.
Research question
To investigate the relationship between the numbers of carbon atoms in an alcohol chain; methanol,
Ethanol and propanol and their respective standard enthalpy change of complete combustions.
Modifications to the methodology
The original experiment was modified by investigating the addition of two other alcohols so that the research could be answered. This also involved taking 5 tests for each alcohol this was done so that the most accurate results were gained. It is assumed that no heat escapes into surrounding but limit the effect of this assumption we put two heatproof mats either side of the spirit lamp so that as much heat was maintained and focused onto the water. In addition to this, a chimney was made so that the flame its self and heat was funnelled onto the water beaker. Aluminium foil was added to surround the temperature probe so that the plastic did not melt.
Management of risks
Hazard Risk Precaution Comments Glassware (beaker) When it gets hot you could burn your hand or you could drop it and break it and cut yourself Use tongs when removing it from the clamp stand. Don’t do the clamp up tight. Dispose of glass appropriately if broken and record any injuries Alcohol Flammable, harmful. Methanol is toxic leading to blindness if swallowed Wear PPE, especially safety glasses and gloves. Wash hands after use. Make sure there is ventilation such as an open window. Seek medical attention if you get burned or ingest any fuels. Metal stand Could fall off the table and break your foot Make sure the setup is position in the middle of the workbench.
Variables
The dependent variable, which I will be measuring, is the temperature rise.
My independent variable is the alcohol/number of carbon atoms.
My control variables are:
• the temperature rise of the water*
• volume of water to be heated†
• the same distance between the spirit burner and the boiling tube
• the same spirit burner each time. I will rinse it out each time with the new alcohol used
* I cannot control this exactly as the temperature might carry on rising after I’ve put out the flame, but I will make sure
that I record the highest temperature reached. I will also stir the water with the thermometer to make sure I get as
accurate result as I can
† I will measure the volume of water as accurately as I can, but I will be limited by the accuracy of the measuring
cylinder. As the density of water is 1.0 g/cm3
, I will measure the mass of the water each time to make sure I get an
accurate measurement.
Qualitative observations
The flame height and direction varied throughout the several tests. Even though the chimney was designed to focus the flame the height still varied. As the metals and clamps were kept at the same distances between tests the different flame hight could affect how much heat was being absorbed by the water. There is not much that could be done to prevent this. The alcohol was colourless and the flame was odourless. The flame was divided into two sections, one was blue and one was yellow.
Summary Data
Methanol Experiment Trial 1 Trial 2 Trial 3 Trial 4 Trial 5 Mass of water, g 100.7 99.6 99.7 98.9 101.1 Start Temperature, OC 25.5 24 23.8 25.8 23.8 End Temperature, OC 80.1 83.2 86.9 87.9 88.2 Temperature Changed, OC 54.6 59.2 63.1 62.1 64.4 Start mass (fuel + burner), g 152.44 139.64 128.37 144.07 133.16 End mass (fuel + burner), g 140.11 123.92 116.24 133.77 120.01 Mass of fuel used, g 12.33 15.72 12.13 10.03 13.15
Table 1 – Methanol summarised data.
Ethanol Experiment Trial 1 Trial 2 Trial 3 Trial 4 Trial 5 Mass of water, g 99.3 101.6 99.8 100 102.11 Start Temperature, OC 25.1 25.2 24.3 25 24.1 End Temperature, OC 88.5 85.1 86.9 87.9 88.2 Temperature Changed, OC 63.4 59.9 62.6 62.9 64.1 Start mass (fuel + burner), g 135.96 141.85 134.93 153.29 131.11 End mass (fuel + burner), g 128.67 131.95 124.02 144.57 121.85 Mass of fuel used, g 7.29 9.9 10.91 8.72 9.26
Table 2 – Ethanol summarised data
Propanol Experiment Trial 1 Trial 2 Trial 3 Trial 4 Trial 5 Mass of water, g 99.03 100.76 100.12 99.89 98.99 Start Temperature, OC 24.2 23.9 25.3 26.2 24.1 End Temperature, OC 86.3 84.4 86.2 95 85.4 Temperature Changed, OC 62.1 60.5 60.9 68.8 61.3 Start mass (fuel + burner), g 135.57 145.59 106.64 129.68 102.93 End mass (fuel + burner), g 126.52 135.14 95.52 119.79 92.7 Mass of fuel used, g 9.05 10.45 11.12 9.89 10.23
Table 3 – Propanol summarised data
These are outliers and won’t be included in the average. The outliers were determined using the interquartile range method.
Processing data
The summarised data was processed to determine the molar heat of the three alcohols shown in Table 4. The researched molar heat values of the three alcohols were used as the ‘true’ value or theoretical values at laboratory conditions. This value was compared with the experimental molar heat produced to determine the accuracy of the experimental results and, therefore, the validity of the experimental process. The measurement uncertainty was converted to percentage uncertainty and propagated to determine the precision of the experimental results and, therefore, the reliability of the experimental process. A spreadsheet program was used to graph the experimental results to allow patterns to be examined.
Formula to process data Sample calculation for methanol Average mass of fuel used = Average mass of fuel used = = 12.672 g Average Δ temperature= Average Δ temperature = = 60.68 Uncertainty = ± $\frac{\mathit{range}}{2}$ Uncertainty of Δ temperature = ± = 60.68 OC ± 4.9 Uncertainty = ± $\frac{\mathit{range}}{2}$ Uncertainty of mass of fuel used = ± = 12.672 g ± 2.845 Percentage uncertainty = $\frac{2.845}{12.672}×100=22.4511%$ Percentage uncertainty = 22.4511% Percentage uncertainty = $\frac{4.9}{60.68}×100=8.07514832%$ Percentage uncertainty = 8.07514832% Heat of combustion = mcΔt Heat of combustion = 100 x 4.168 x 60.68 = 25 400.648 j = 25.4 kj Moles of Methanol Burnt = Average Mass of Methanol Burnt = 12.672g Molar Mass of Methanol = CH3OH = (12.01) + (4 x 1.01) + (16) = 32.05 g/mol Moles of Methanol Burnt = $\frac{12.672}{32.05}$ = 0.39538 mol Molar Heat of Methanol = Molar Heat of Methanol = $\frac{25.4}{0.39538}$ = 64.241995 kJ/mol Percentage error = x 100% Percentage error = $\frac{726–64}{726}$ x 100% = 91.18%
Formula to process data Sample calculation for ethanol Average mass of fuel used = Average mass of fuel used = $\frac{7.29+9.9+10.91+8.72+9.26}{5}$ = 9.216 g Average Δ temperature= Average Δ temperature = $\frac{63.4+59.9+62.6+62.9+64.1}{5}$ = 62.58 Uncertainty = ± $\frac{\mathit{range}}{2}$ Uncertainty of Δ temperature = ± $\frac{64.1–59.9}{2}$ = 62.58OC ± 2.1 Uncertainty = ± $\frac{\mathit{range}}{2}$ Uncertainty of mass of fuel used = ± $\frac{10.91–7.29}{2}$ = 9.216g ± 1.81 Percentage uncertainty = $\frac{2.1}{62.58}×100=3.36%$ Percentage uncertainty = 3.36% Percentage uncertainty = $\frac{1.81}{9.216}×100=19.64%$ Percentage uncertainty = 19.64% Heat of combustion = mcΔt Heat of combustion = 100 x 4.168 x 62.58 = 26196 j =26.20 kj Moles of ethanol Burnt = Average Mass of ethanol Burnt = 9.216g Molar Mass of ethanol = C2H5OH = (12.01 x 2) + (6 x 1.01) + (16) = 46.08 g/mol Moles of ethanol Burnt = $\frac{9.216}{46.08}$ = 0.2 mol Molar Heat of ethanol = Molar Heat of ethanol = $\frac{26.20}{0.2}$ = 131 kJ/mol Percentage error = x 100% Percentage error = $\frac{1360–131}{1360}$ x 100% = 90.37%
Formula to process data Sample calculation for propanol Average mass of fuel used = Average mass of fuel used = = 10.148 g Average Δ temperature= Average Δ temperature = = 62.72 Uncertainty = ± $\frac{\mathit{range}}{2}$ Uncertainty of Δ temperature = ± = 62.72 OC ± 4.15 Uncertainty = ± $\frac{\mathit{range}}{2}$ Uncertainty of mass of fuel used = ± = 10.148 g ± 1.035 Percentage uncertainty = $\frac{4.15}{62.72}×100=6.62%$ Percentage uncertainty = 6.62% ercentage uncertainty = $\frac{1.035}{10.148}×100=10.1991%$ Percentage uncertainty =10.1991% Heat of combustion = mcΔt Heat of combustion = 100 x 4.186 x 62.72 = 26254.6 j = 26.25 kj Moles of Methanol Burnt = Average Mass of Methanol Burnt = 10.148g Molar Mass of Methanol = C3H7OH = (12.01 x 3) + (8 x 1.01) + (16) = 60.11 g/mol Moles of Methanol Burnt = $\frac{10.148}{60.11}$ = 0.168824 mol Molar Heat of Methanol = Molar Heat of Methanol = $\frac{26.25}{0.168824}$ = 155.487 kJ/mol Percentage error = x 100% Percentage error = $\frac{2021–155.487}{2021}$ x 100% =92.257 %
Alcohol Formula Number of Carbon Atoms Molar Heat Percentage Error Methanol CH3OH 1 64.241995 kJ/mol 91.18% Ethanol C2H5OH 2 131 kJ/mol 90.37% Propanol C3H7OH 3 155.487 kJ/mol 92.257%
Graph 1 – Experimental values graphed against the number of carbon atoms in the organic solution
Graph 2 – Experimental Values and True Values
Trends patterns and relationships
It is interesting that the experimental value of ethanol -while still on the line- appears as lower
than the other experimental values. This is not observed in the values based on BE where the five
energy values are perfectly aligned. Ethanol´s value is clearly lower than that of methanol and
slightly lower than the other higher alcohols.
Therefore there seems to be some structural difference between ethanol and the rest, with a
more marked variation with the first member of the homologous series. I tend to believe that this
may result from the significantly lower inductive effect that the ethyl group has on the C-O bond
when compared with the methyl group. If the inductive effect is lower the bond is less polar,
resulting in an increased covalent character and therefore a stronger bond. As the bond is
stronger more energy is needed to break it, and the enthalpy change would therefore be smaller.
The inductive effect is not changed by adding CH2 in the higher alcohols but still there must be
some, as they are slightly lower than methanol (but perfectly aligned with each other). Still other
possibility is that differences result from experimental errors which references do not report.
Results may suggest that the difference in the bond O-H could be affecting alcohols to a different
degree. More data are needed to clarify why the second CH2 affects the C-O bond in ethanol but
not in the rest providing a satisfactory explanation for this anomaly.
Limitations of evidence reliability and viability
1) Around 90% of the heat from the spirit lamp did not reach the base of the tripod stand itself. This
was the main reason of error. Heat was lost very easily. A lot of heat was lost in this manner and
contributed to a lower than expected temperature change in the water. This was undoubtedly, the
main source of experimental error.
2) Although, the copper calorimeter was properly insulated, heat loss was prevalent. The lid had a
hole to allow the thermometer to be placed inside. This meant heat could be lost in this manner as
well.
3) The mass of water might not have been constant throughout the heating process. Some of the
water might have evaporated off, suggesting a mass loss. This would then give different results.
4) It was observed that during the combustion of alcohols, a yellow flame was obtained at times.
This is the sign of the incomplete combustion of alcohols. As a result, carbon monoxide is formed
instead of carbon dioxide. Therefore, this incomplete combustion results in low standard enthalpy
of combustion values as the reaction is not complete.
5) During calculations, the specific heat capacity of the copper calorimeter was not included. This is
wrong. The copper beaker did absorb some heat from the spirit lamp. This should have been
added onto the heat energy absorbed by the water. Due its absence, a lot of heat was absorbed
through the copper calorimeter itself, and this was not calibrated.
Conclusion
I may finally conclude that my hypothesis has been validated both by experimental values found in
cited resources and those calculated using bond energies. The investigation has evidenced that
there is a positive linear relationship between the ΔH of combustion and the number of C atoms in
a homologous series of simple alcohols. It has also shown that results based on bond energies are
lower than those experimentally obtained underlining the relevance of chemical environments in
the energy needed to break specific bonds even when extremely similar. An unexpected small
anomaly was found in the experimental value of ethanol which is not shown in the trend based on
bond energies, reinforcing the limitations that average values may impose on accurate
descriptions
Suggested improvements and extensions
1) This experiment could have been carried out at a place of constant temperature.
2) The calorimeter could have been insulated more. A thick cotton wool could have been added.
3) Minimize the heat lost by ensuring no gas (vapour) is lost during the heating process, by adding
more cotton for insulation or covering the calorimeter with a thick lid.
4) Black coloured cardboard can also be used for preventing heat loss.
5) Stir the water at all times to distribute heat evenly.
6) Blow out the spirit lamp as soon as possible. A delay here means that there is more loss of
alcohol.
7) Carry out the experiment in the presence of excess oxygen to ensure that no incomplete
combustion takes place.
8) Repeat with a much larger variety of alcohols. (C6H13OH, C7H15OH, C8H17OH, etc).
Some alcohols also have slightly different structures. The alcohols we had to choose from included propan2-ol.
This means that the OH group was at a different position in the alcohol. We should test some of these
different alcohols to see if our finding still stands.
It may also be difficult to transfer our results to the real world. Fuels are not usually pure chemicals but
mixtures (for instance alkane fuels). It is likely that alcohol fuels are mixtures of alcohols and not pure. We do
not know from the new methods of production of alcohol fuels ([5] and [6]) how pure the alcohols for the
fuels will be (and mixtures may be better).
Methanol has the lowest combustion energy, but it also needs the least oxygen to burn (see page 6). It
therefore has the lowest chemically correct air-fuel ratio, so an engine burning methanol would have the
most power [1]. But alcohols with fewer carbon atoms might be a problem on a hot summer’s day or at high
altitudes. From butanol upwards, the alcohols are relatively insoluble in water, and will attract less, making
them better for engines.
## Raw Data
Trial 1
Beaker – 57.96 g Ethanol Propanol Methanol Mass of spirit lamp + alcohol 135.96g 135.57 152.44 Mass of water 99.3g 99.03g 100.7 Initial temp of the water 25.1 24.2 25.5 Water temp 20 sec 25.4 24.7 25.6 Water temp 40 min 27.7 26.6 25.7 Water temp 1 min 31 28.1 27.1 Water temp 1:20 min 34.8 29.4 29.7 Water temp 1:40 min 40.1 30.8 31 Water temp 2 min 47.1 32.5 34.4 Water temp 2:20 min 55.5 35.3 38.4 Water temp 2:40 min 65.6 40 41.5 Water Temp 3 min 76.6 45.8 45.7 Water Temp 3:20 min 88.5 48.8 51.8 Water Temp 3:40 min 56.2 57.8 Water Temp 4 min 63.8 63.5 Water Temp 4:20 min 71.9 69.9 Water Temp 4:40 min 78.8 76.1 Water Temp 5 min 86.2 80.1 Final Temp of water 88.5 86.2 80.1 Mass of spirit lamp + remaining alcohol 128.67 126.52 140.11
Trial 2
Beaker – 57.96 g Ethanol Propanol Methanol Mass of spirit lamp + alcohol 141.85g 145.59 139.64 Mass of water 101.6g 100.76 99.6 Initial temp of the water 25.2 23.9 24 Water temp 20 sec 25.2 24.1 23.9 Water temp 40 sec 25.4 24.8 24.8 Water temp 1 min 26.7 25.8 25.3 Water temp 1:20 min 27.5 27.3 27 Water temp 1:40 min 28.5 29.6 29 Water temp 2 min 31.8 30.6 30.5 Water temp 2:20 min 36 32.4 32.8 Water temp 2:40 min 40.6 34 36.3 Water Temp 3 min 46.6 36.2 41.4 Water Temp 3:20 min 55.4 38.4 44.1 Water Temp 3:40 min 63.2 40.6 46 Water Temp 4 min 70.6 42.3 49.7 Water Temp 4:20 min 76.1 44.3 54.5 Water Temp 4:40 min 85.1 46.7 58.2 Water Temp 5 min 50.8 63.8 Water Temp 5:20 min 55.4 69 Water Temp 5:40 min 62.5 73.6 Water Temp 6 min 70.1 78 Water Temp 6:20 min 77.8 80.5 Water Temp 6:40 min 84.4 Water Temp 7 min Final Temp of water 85.1 84.4 83.2 Mass of spirit lamp + remaining alcohol 131.95 135.14 123.92
Data from other groups includes trials 3 to 5.
Methanol Trial 3 Trial 4 Trial 5 Mass of spirit lamp + methanol 128.37g 144.07g 133.16g Mass of distilled water 99.7 98.9 101.1 The initial temperature of the distilled water oC 23.8 oC 25.0 oC 23.8 oC Water temperature 20s 23.8 oC 25.2 oC 24.5 oC Water temperature 40s 25.6 oC 26.5 oC 25.3 oC Water temperature 60s 28.5 oC 29.4 oC 27.5 oC Water temperature 80s 32.4 oC 35.9 oC 30.9 oC Water temperature 100s 37.8 oC 37.8 oC 36.2 oC Water temperature 120s 41.7 oC 40.1 oC 42.6 oC Water temperature 140s 47.6 oC 46.5 oC 50.4 oC Water temperature 160s 54.0 oC 54.3 oC 57.6 oC Water temperature 180s 60.2 oC 61.5 oC 63.9 oC Water temperature 200s 69.2 oC 70.8 oC 70.2 oC Water temperature 220s 77.2 oC 79.9 oC 80.6 oC Water temperature 240s 86.9 oC 87.9 oC 88.2 oC Point where reaction had a temperature increase of 60OC Between 220-240s at 83.8oC Between 220-240s at 85.0oC Between 220-240s at 83.8 oC Mass of spirit lamp + remaining methanol 116.24g 133.77g 120.01g Mass of methanol used in the reaction 12.13g 10.3g 13.15g
Ethanol Trial 3 Trial 4 Trial 5 Mass of spirit lamp + ethanol 134.93g 153.29g 131.11 Mass (volume) of distilled water 99.8 100 102.11 The initial temperature of the distilled water oC 24.3 oC 25.0 oC 25.0 oC Water temperature 20s 24.8oC 25.5 oC 25.1 oC Water temperature 40s 26.7 oC 26.8 oC 26.7 oC Water temperature 60s 29.2 oC 28.6 oC 27.7 oC Water temperature 80s 31.9 oC 31.1 oC 30.6 oC Water temperature 100s 34.4 oC 34.4 oC 35.6 oC Water temperature 120s 39.1 oC 40.5 oC 43.5 oC Water temperature 140s 43.4 oC 45.8 oC 51.3 oC Water temperature 160s 54.3 oC 54.8 oC 60.5 oC Water temperature 180s 58.2 oC 65.8 oC 70.7 oC Water temperature 200s 65.7 oC 72.6 oC 82.4 oC Water temperature 220s 77.7 oC 82.2 oC 97.4 oC Water temperature 240s 87.7 oC 96.4 oC 100 oC Point where reaction had a temperature increase of 60OC Between 220-240s at 84.3oC Between 220-240s at 85.0oC Between 200-220s at 85.0 oC Mass of spirit lamp + remaining ethanol 124.02g 144.57g 121.85g Mass of ethanol used in the reaction 10.91g 8.72g 9.26g
Propanol Trial 3 Trial 4 Trial 5 Mass of spirit lamp + propanol 106.64g 129.68g 102.93g Mass (volume) of distilled water 100.12 99.89 98.99 The initial temperature of the distilled water oC 25.3 oC 26.2 oC 24.1 oC Water temperature 20s 26.1 oC 26.9 oC 25.7 oC Water temperature 40s 28.2 oC 28.0 oC 30.4 oC Water temperature 60s 32.1 oC 31.9 oC 35.0 oC Water temperature 80s 34.4 oC 36.8 oC 37.6 oC Water temperature 100s 38.7 oC 44.7 oC 41.7 oC Water temperature 120s 47.8 oC 49.7 oC 47.7 oC Water temperature 140s 59.7 oC 58.3 oC 62.1 oC Water temperature 160s 72.4 oC 66.7 oC 71.2 oC Water temperature 180s 84.3 oC 80.9 oC 83.2 oC Water temperature 200s 98.7 oC 99.2 oC 99.3 oC Water temperature 220s 100.2 oC Over 100 oC and boiling Over 100 oC and boiling Water temperature 240s Over 100 oC and boiling Over 100 oC and boiling Over 100 oC and boiling Point where reaction had a temperature increase of 60OC Between 180-200s at 85.3 oC Between 180-200s at 85.0 oC Between 180-200s at 85.0 oC Mass of spirit lamp + remaining propanol 97.99g 119.53g 93.18g Mass of propanol used in the reaction 8.65g 10.15g 9.75g
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2020-02-26 03:03:51
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https://stats.stackexchange.com/questions/292383/image-classification-using-image-augmentation-to-resolve-class-imbalance
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# Image classification: Using image augmentation to resolve class imbalance
I am working on an image based classification task with some significant class imbalance in the training database of images (largest class: 4967 images, smallest class: 61 images).
I will be experimenting with two different machine learning approaches for this purpose (SVM and CNN), and will need to use the same training data for each approach.
I was planning on synthesizing additional training data by applying some simple transformations to the original images (rotation, flipping, and altering brightness), and think this is a good opportunity to also resolve the problem of class imbalance by creating more augmented images for the less frequent image classes.
My query regarding this essentially has two elements:
1) Is there a sensible limit to how much data I can synthesize in this manner? Obviously I could increase the frequency of the least frequent class by a factor of 359 if I simply apply rotation transformations in 1 degree steps. However, I am concerned creating many similar images from the same source image will result in over-fitting, or have some other negative impact.
2) If there is a limit on the amount of data synthesis it is sensible to do: can any one offer advice on balancing the trade-off between not synthesizing too much data and reducing class imbalance via data augmentation?
I would be particularly interested in input from anyone who has dealt with similar problems in practice before
• Keep in mind that transformations multiply each class by some fixed number $K$, unless you only focus on the lower classes. In either case, be wary that these transformations will not guarantee your model will generalize well. Just because you can turn your 61 images to say, 1000, doesn't mean your model will go on to predict that class very well. – Alex R. Nov 20 '17 at 21:46
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2019-09-21 15:34:02
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https://cdsweb.cern.ch/collection/EP%20Preprints?ln=fr&as=1
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# EP Preprints
Derniers ajouts:
2022-05-19
10:28
Measurement of antiproton production from antihyperon decays in $pHe$ collisions at $\sqrt{s_{NN}}=110$ GeV The interpretation of cosmic antiproton flux measurements from space-borne experiments is currently limited by the knowledge of the antiproton production cross-section in collisions between primary cosmic rays and the interstellar medium. [...] arXiv:2205.09009 ; CERN-EP-2022-091 ; LHCB-PAPER-2022-006. - 2022. Fulltext - Related data file(s)
2022-05-19
09:25
Search for $CP$ violation using $\hat{T}$-odd correlations in $B^{0} \to p \bar p K^{+} \pi^{-}$ decays A search for $CP$ and $P$ violation in charmless four-body $B^{0} \to p \bar p K^{+} \pi^{-}$ decays is performed using triple-product asymmetry observables. [...] arXiv:2205.08973 ; CERN-EP-2022-083 ; LHCB-PAPER-2022-003. - 2022. Fulltext - Cover note
2022-05-12
16:38
Measurement of the prompt $D^0$ nuclear modification factor in $p$Pb at $\sqrt{s_{NN}}$ = 8.16 TeV The production of prompt $D^0$ mesons in proton-lead collisions in the forward and backward configurations at a center-of-mass energy per nucleon pair of $\sqrt{s_\mathrm{NN}} = 8.16~\mathrm{TeV}$ is measured by the LHCb experiment. [...] arXiv:2205.03936 ; LHCb-PAPER-2022-007,CERN-EP-2022-082 ; LHCb-PAPER-2022-007 ; CERN-EP-2022-082. - 2022. Fulltext - Related data file(s) - Supplementary information - Fulltext
2022-04-28
12:25
Evidence for modification of $b$ quark hadronization in high-multiplicity $pp$ collisions at $\sqrt{s} = 13$ TeV The production rate of $B^{0}_{s}$ mesons relative to $B^{0}$ mesons is measured by the LHCb experiment in $pp$ collisions at a center-of-mass energy $\sqrt{s} = 13$ TeV over the forward rapidity interval $2 < y < 4.5$ as a function of the charged particle multiplicity measured in the event. [...] arXiv:2204.13042 ; LHCb-PAPER-2022-001 ; CERN-EP-2022-062 ; LHCB-PAPER-2022-001. - 2022. Fulltext - Related data file(s) - Supplementary information - Fulltext
2022-04-28
11:11
Measurement of $CP$ asymmetries in $D^+_{(s)}\rightarrow \eta \pi^+$ and $D^+_{(s)}\rightarrow \eta^{\prime} \pi^+$ decays Searches for $CP$ violation in the decays $D^+_{(s)}\rightarrow \eta \pi^+$ and $D^+_{(s)}\rightarrow \eta^{\prime} \pi^+$ are performed using $pp$ collision data corresponding to 6 fb$^{-1}$ of integrated luminosity collected by the LHCb experiment. [...] arXiv:2204.12228 ; CERN-EP-2022-035 ; LHCb-PAPER-2021-051. - 2022. Fulltext - Related data file(s) - Fulltext
2022-04-27
13:38
Observation of sizeable $\omega$ contribution to $\chi_{c1}(3872) \to \pi^+\pi^- J/\psi$ decays Resonant structures in the dipion mass spectrum from $\chi_{c1}(3872)\to\pi^+\pi^- J/\psi$ decays, produced via $B^+\to K^+\chi_{c1}(3872)$ decays, are analyzed using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9 fb$^{-1}$. [...] arXiv:2204.12597 ; LHCb-PAPER-2021-045 ; CERN-EP-2022-049 ; LHCB-PAPER-2021-045. - 2022. Fulltext - Related data file(s) - Fulltext
2022-04-22
17:01
Nuclear modification factor of neutral pions in the forward and backward regions in $p$Pb collisions The nuclear modification factor of neutral pions is measured in proton-lead collisions collected at a center-of-mass energy per nucleon of $8.16$ TeV with the LHCb detector. [...] arXiv:2204.10608 ; LHCb-PAPER-2021-053 ; CERN-EP-2022-050 ; LHCB-PAPER-2021-053. - 2022. Fulltext - Related data file(s) - Supplementary information - Fulltext
2022-04-21
15:54
Search for the doubly heavy baryon $\it{\Xi}_{bc}^{+}$ decaying to $J/\it{\psi} \it{\Xi}_{c}^{+}$ A first search for the $\it{\Xi}_{bc}^{+}\to J/\it{\psi}\it{\Xi}_{c}^{+}$ decay is performed by the LHCb experiment with a data sample of proton-proton collisions, corresponding to an integrated luminosity of $9\,\mathrm{fb}^{-1}$ recorded at centre-of-mass energies of 7, 8, and $13\mathrm{\,Te\kern -0.1em V}$. [...] arXiv:2204.09541 ; LHCb-PAPER-2022-005 ; CERN-EP-2022-048. - 2022. - 16. Fulltext - Related data file(s) - Fulltext
2022-02-23
11:31
Search for single scalar and vector leptoquark production in e-photon scattering at $\sqrt{s}$ = 189 GeV with the DELPHI detector / Benekos, N C ; Papadopoulou, T D DELPHI-99-47-PHYS-821. - 2001. - 17 p.
2022-02-21
17:10
Measurement of the charm mixing parameter $y_{CP} - y_{CP}^{K\pi}$ using two-body $D^0$ meson decays / LHCb Collaboration A measurement of the ratios of the effective decay widths of $D^0 \to \pi^-\pi^+$ and $D^0 \to K^-K^+$ decays over that of $D^0 \to K^-\pi^+$ decays is performed with the LHCb experiment using proton-proton collisions at a centre-of-mass energy of $13\,\mathrm{TeV}$, corresponding to an integrated luminosity of $6\,\mathrm{fb^{-1}}$. [...] arXiv:2202.09106 ; LHCb-PAPER-2021-041 ; CERN-EP-2022-022 ; LHCB-PAPER-2021-041. - 2022. - 27 p. Fulltext - Related data file(s) - Supplementary information - Fulltext
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2022-05-20 03:16:00
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http://geocalc.clas.asu.edu/GA_Primer/GA_Primer/introduction-to-geometric/defining-and-interpreting.html
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Defining and Interpreting the Geometric Product
Previous section: Introduction to Geometric Algebra and Basic 2D Applications.
Next sectionRotors and Rotations in the Euclidean Plane.
The algebraic properties of vector addition and scalar multiplication are insufficient to characterize the geometric concept of a vector as a directed line segment, because they fail to encode the properties of magnitude and relative direction. That deficiency is corrected by defining suitable algebraic rules for multiplying vectors.
Geometric product:
The product ab for
vectors a, b, c is defined by the rules
• Associative: (ab)c = a(bc)
• Left distributive: a(c) = ab + ac
• Right distributive: (c)a = ba + ca
• Euclidean metric: a2 a2,
where a = |a| is a positive scalar (= real number) called the magnitude of a
In terms of the geometric product ab we can define two other products, a symmetric inner product
(1) a= ½(ab baba
and an antisymmetric outer product
(2) ab = ½(ab ba) = − ba
Adding (1) and (2), we obtain the fundamental formula
(3) ab = ab + ab called the expanded form for the geometric product.
is to provide geometric interpretations for these three products.
Exercise: For a triangle defined by the vector equation a + b = c,
derive the standard Law of Cosines: a2 b2 2ac2, and so prove that the inner product ab is always scalar-valued.
{Just multiply c2 = (a + b) (a + b) and use the Euclidean metric above and definition (1) above for the inner product.
Notice also that
if a and b are perpendicular, using the Pythagorean Theorem we can conclude ab is zero (and vice versa).
Further,
if a and b are perpendicular, using formulas (1) & (2) above, ab = ab = ½(ab − ba), which means ab = − ba.}
Therefore, the inner product can be given the usual geometric interpretation as the length of a perpendicular projection of one line segment on the direction of another.
The outer product ab = − ba generates a new kind of geometric quantity called a bivector, that can be interpreted geometrically as directed area in the plane of a and b.
We have shown that the geometric product interrelates three kinds of algebraic entities: scalars (0-vectors), vectors (1-vectors), and bivectors (2-vectors) that can be interpreted as geometric objects of different dimension. Geometrically, scalars represent 0-dimensional objects, because they have magnitude and orientation (sign) but no direction. Vectors represent directed line segments, which are 1-dimensional objects. Bivectors represent directed plane segments, which are 2-dimensional objects. It may be better to refer to a bivector
$\Large{{\bf{B}} = B{\bf{\hat B}}}$
as a
directed area, because its magnitude B = |B| is the ordinary area of the plane segment and its direction
$\Large{{{\bf{\hat B}}}}$
represents the plane (and orientation) in which the segment lies, just as a unit vector represents the direction of a line. The shape of the plane segment is not represented by any feature of B, as expressed in the following equivalent geometric depictions for B (with
counterclockwise orientation):
Prove the following:
Given any non-zero vector a in the plane of bivector B, one can find a vector b such that
B = ba = –ab
B2 = −|B|2 = −a2b2,
aB = –Ba, that is, B anticommutes with every vector in the plane of B
{Looking again at the depictions directly above, it should be clear we can pick a b perpendicular to a
and also in the plane of B so that the rectangle depicting ba has the magnitude and orientation of B.
Further, since we've picked
b to be perpendicular to a, by the arguments in the exercise above,
ba = ba = – ab. Then, B2 = (ab) (ba) = – a2b2 = − a2b2 = |B|2 < 0.
Finally,
aB – aab = − a2= − baa = – Ba.}
Every vector a has a multiplicative inverse:
$\Large{{{\bf{a}}^{ - 1}} = \frac{1}{{\bf{a}}} = \frac{{\bf{a}}}{{{a^2}}}}$
that is, geometric algebra makes it possible to divide by vectors.
{Simply multiply a on either side by a/a2. As usual, we must assume a≠0.}
Prove the following theorems about the geometric meaning of commutivity and anticommutivity:
ab 0 ab = −ba Orthogonal vectors anticommute!! {See the exercise above.}
= λb a0 ab ba Collinear vectors commute!!
The problem remains to assign geometric meaning to the quantity ab without expanding it into inner and outer products.
Previous sectionIntroduction to Geometric Algebra and Basic 2D Applications.
Next section: Rotors and Rotations in the Euclidean Plane.
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2017-09-20 21:53:16
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|
https://solvedlib.com/type-of-electromagnetic-radiation-frequency-range,55798
|
Type of Electromagnetic Radiation Frequency Range (H) 7.5 x 10"- 3 x 10" Energy Range (J)...
Question:
Type of Electromagnetic Radiation Frequency Range (H) 7.5 x 10"- 3 x 10" Energy Range (J) 5 x 10-19 - 2x 10-17 Ultraviolet Visible Infrared 3 x 10" - 4 x 10" 2x 10-22-3x 10" The frequency and energy ranges of photos in some parts of the electromagnetic spectrum are given in the table above. Which of the following could be the energy of a photon in the visible range? (A) 9 x 101 4x10 » @ xong (oax 100g
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DeneanMetrics 2.1 pto Conotn ,ntd440'{0 4342 Mlon 3013 Crte repored prula d Onan1b004ldr *on Fotul ha proftabety 0l Eetatea Atn cuibuttm Uuct T LAETTAAI Anomadm Heemanan ctnunnrulnin Fq contnountr Omamo omaratu In lenntdn CAlinGn Lonam Aaabeze Fanrtgn814ud [rh purue Uarllyninumn {ttng Roibton atet @CenantaCorpaye GenEwu {7 Tianon 39 LJ o 4GE u MAru arannCrahte Eadtne Alnanet(RoLndtha ~MChFafeatynhoaEduoher Mlut d 670eba )ntha tl4CozpieaCoreanwFnutdeut
Denean Metrics 2.1 pto Conotn ,ntd440'{0 4342 Mlon 3013 Crte repored prula d Onan1b004ldr *on Fotul ha proftabety 0l Eetatea Atn cuibuttm Uuct T LAETTAAI Anomadm Heemanan ctnunnrulnin Fq contnountr Omamo omaratu In lenntdn CAlin Gn Lonam Aaabeze Fanrtgn814ud [rh purue Uarllyninumn {ttng Roibt...
CHCH;CH;CHCH;CH;CH;CH_CH= CHCH;CH==CHCH;CHCH CHCH,CH;CH;CH;CHCH,CH,CH_CH;
CHCH; CH; CHCH; CH; CH;CH_ CH= CHCH;CH==CH CH;CHCH CHCH,CH; CH; CH;CHCH, CH,CH_CH;...
A(n) _____ alcohol is one in which there is only one hydrocarbon group attached to the carbon atomholding the hydroxyl group.
A(n) _____ alcohol is one in which there is only one hydrocarbon group attached to the carbon atom holding the hydroxyl group....
Consider the following function over real variable x: r = 1 -x + 4 ((x -...
Consider the following function over real variable x: r = 1 -x + 4 ((x - 2)2 a) Plot function f(x) over x when x varies from 1 to 5. X < 3 x > 3 b) Write a MATLAB program to solve the following optimization problem using exhaustive search: minimize f(x) subject to x > 1 x 55...
'24k Sinplfy each. (Write answer in standard ferm) 1) (17_435)- (14+7i) = 2)) ~8i (-9) 3) (i5+ii)-lsi_1) ) 6+4)= (2+6i)+(2+60) =- (+7)(9-2;)Eyh Let fo= -x26x+28 and h6 =-2+Ix-x2Eid: a.) (h-fJo)= 6.) (f+hJo
'24k Sinplfy each. (Write answer in standard ferm) 1) (17_435)- (14+7i) = 2)) ~8i (-9) 3) (i5+ii)-lsi_1) ) 6+4)= (2+6i)+(2+60) =- (+7)(9-2;) Eyh Let fo= -x26x+28 and h6 =-2+Ix-x2 Eid: a.) (h-fJo)= 6.) (f+hJo...
Lnemomentotnenu 1 QWESTISN 4 L OmctUm L Wyvhed( t0 612 rpm trom rest TOaontneiyu1 L 1 1
lnemomentotnenu 1 QWESTISN 4 L OmctUm L Wyvhed( t0 612 rpm trom rest TOaontneiyu 1 L 1 1...
Draw a photo depicting a proton that moves at 2.5 x 106 m/s horizontally at a...
Draw a photo depicting a proton that moves at 2.5 x 106 m/s horizontally at a right angle to a magnetic field. (i think you have to use right hand rule)...
A waxy cuticle helps land plants _____________. a. conserve waterc. reproduceb. take up carbon dioxided. stand upright
A waxy cuticle helps land plants _____________. a. conserve water c. reproduce b. take up carbon dioxide d. stand upright...
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2022-07-05 22:47:11
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http://openstudy.com/updates/55ae61c8e4b045595079e820
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anonymous one year ago How many liters of 0.85 M HCl solution would react completely with 3.5 moles Ca(OH)2? Ca(OH)2(s) + 2 HCl(aq) yields CaCl2(aq) + 2 H2O(l) 1.5 L HCl(aq) 8.2 L HCl(aq) 2.1 L HCl(aq) 6.0 L HCl(aq)
1. anonymous
@Nnesha
2. anonymous
@e.mccormick
3. JFraser
See the molar ratio from the balanced reaction? Telling you every time you use 1 mole of calcium hydroxide, you need $$two$$ miles of HCl to react fully with it
4. anonymous
@jfraser so c
5. JFraser
No. The problem says you start with 3.5 moles of calcium hydroxide, so how many moles of HCl will fully react with that much? (Twice as much)
6. JFraser
The balanced reaction tells us $$ratios$$, not absolute amounts
7. anonymous
@jfraser so d would be correct?
8. JFraser
You're jumping. Stop jumping. If you have to use 3.5 moles of calcium hydroxide, you must also use 7 moles of HCl. But the question is asking about the $$volume$$ of HCl solution needed. The $$concentration$$ of the HCl is 0.85mol/L
9. anonymous
oh so b @jfraser thanks
10. JFraser
Each 1L of solution contains only 0.85 moles of HCl $7mol HCl * \frac{1L HCl}{0.85mol HCl}$
11. JFraser
Ye
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2017-01-16 12:53:11
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http://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/IfcCartesianPoint.htm
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# 8.9.3.12 IfcCartesianPoint
## 8.9.3.12.1 Semantic definition
An IfcCartesianPoint defines a point by coordinates in an orthogonal, right-handed Cartesian coordinate system. For the purpose of this specification only two and three dimensional Cartesian points are used.
## 8.9.3.12.6 Formal representation
ENTITY IfcCartesianPoint
SUBTYPE OF (IfcPoint);
Coordinates : LIST [1:3] OF IfcLengthMeasure;
WHERE
CP2Dor3D : HIINDEX(Coordinates) >= 2;
END_ENTITY;
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2023-01-30 14:45:17
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https://cs.stackexchange.com/questions/85211/meaning-of-the-time-hierarchy-theorem
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# Meaning of the Time Hierarchy Theorem
Given two positive integers $c_1$ and $c_2$ such that $c_1 < c_2$, it's easy to prove that $n^{c_1}$ is $\mathcal{O}(n^{c_2})$ while $n^{c_2}$ is not $\mathcal{O}(n^{c_1})$. In general, for any functions $f(n)$ and $g(n)$ it is possible to determine which one (or both) is true, $f \in \mathcal{O}(g)$ or $g \in \mathcal{O}(f)$ using only definition of big-O notation. Thus it is not hard to see that TIME($n^{c_1}) \subsetneq$ TIME($n^{c_2})$ without using the Time Hierarchy theorem.
So, what is the meaning of the Time Hierarchy theorem and how and where can I use it?
You miss the meaning of the Time Hierarchy theorem, or perhaps of the classes TIME($n^k$) that you show.
It is indeed obvious that $O(n^k) \subsetneq O(n^{k+1})$, for instance. It is also clear that the set of Turing machines that run in time $O(n^k)$ is a strict subset of those that run in $O(n^{k+1})$.
However, it is not immediately obvious that the set of problems that can be solved by TMs in time $O(n^k)$ (i.e., the class TIME($n^k$)) is a strict subset of TIME($n^{k+1})$. For this much stronger statement, you need the Time Hierarchy Theorem. That is, you need to argue that there exists some problem that can be solved in time $n^{k+1}$ but not in time $n^k$. (Of course, this is just a special case of applying the theorem to polynomial running times.)
• Thanks for clarification. Now I understand, big-O is used for classifications functions and Turing machines, while TIME($.$) is a problem class. That was the key point. – B.K. Dec 9 '17 at 14:46
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2019-10-24 01:46:08
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|
https://tex.stackexchange.com/questions/356667/width-of-columns-in-a-table-with-only-multicolumns
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# Width of columns in a table with only multicolumns
I want to create a table with this specific structure:
| b | c | d |
| f | g |
So basically a table with 1 line which is cut in half and a second line which is cut in thirds.
I have tried to make the table out of 6 columns and use \multicolumn to make bigger cells out of 2 or 3 smaller ones but that does not work. It looks like the reason is that there is no row which has all 6 columns in it, but I have no idea how I can work around this.
Also, I would like to have the overall width of the table flexible so that it adjusts to the texts in the cells.
Edit: Below I've provided a table exactly as I want it. I tried reducing it to the core of the problem I'm facing, but obviously that was a mistake since it created more questions than it soved. Sorry for that. Note: Every content should be centered in its cell.
| OSI-Schicht | Umsetzung |
----------------------------------------------------------------
----------------------------------------------------------------
| Anwendungsschicht | | | |
-------------------------- | | |
| Darstellungsschicht | SOME/IP | AVB/TSN | DoIP |
-------------------------- | | |
| Sitzungsschicht | | | |
----------------------------------------------------------------
| Transportschicht | TCP | UDP |
----------------------------------------------------------------
| Vermittlungsschicht | IPv4 | IPv6 |
----------------------------------------------------------------
| Sicherungsschicht | Ethernet |
----------------------------------------------------------------
| Bitübertragungsschicht | 100BASE-TX | 100BASE-T1 | 1000BASE-T |
----------------------------------------------------------------
• Welcome to TeX.SE! Should columns b, c, and d be equally wide? Should columns f and g be equally wide? How wide should the table be overall? Should automatic line-breaking be enabled inside cells? Should the cell contents be centered, left-aligned (aka "ragged-right"), fully justified, or arranged in some other way? Please be specific.
– Mico
Mar 3 '17 at 10:38
• Sorry for not being more specific. Yes, b, c and d should be equally wide, as well es f and g. The whole table should be wide enough to fit the text of the cells. Automatic line-breaking would be nice to have, now that you mention it. The contents should be centered. Mar 3 '17 at 10:44
• The criterion "wide enough to fit the text of the cells" isn't sufficient, as we don't know yet what's in the cells. (I take it it's safe to assume that the cells won't contain just single letters...) Please provide more information.
– Mico
Mar 3 '17 at 10:50
• This is perhaps a duplicate of tex.stackexchange.com/questions/354956/… Mar 3 '17 at 11:42
• I've tried to use the solution provided in the link but it does not work in this case. I think it works in the original case because of the exact number of characters in each cell. Since the cells here don't have a regular content it doesn't solve this problem. Mar 3 '17 at 13:02
I suggest to start by determining the (minimum required) column widths of the table:
• It's actually easiest to start with the width of the 2-column cells: This width must be equal to the width of the longest string, which happens to be "100BASE-TX". (The string "1000BASE-T" is ever so slightly shorter.) Call this width, say, \lenb.
• The width of the (latent) single-column cells -- called, say, \lena -- is obtained by solving
6\lena + 12\tabcolsep + 6\arrayrulewidth = 3\lenb + 6\tabcolsep + 3\arrayrulewidth
for \lena: \lena=0.5\lenb-\tabcolsep-\arrayrulewidth/2.
• Similarly, the width of the triple-column cells -- called, say, \lenc -- may be obtained by solving
3\lenb + 6\tabcolsep + 3\arrayrulewidth = 2\lenc + 4\tabcolsep + 2\arrayrulewidth
for \lenc: \lenc=1.5\lenb+\tabcolsep+\arrayrulewidth/2.
Once the three (minimal) lengths are obtained, it's straightforward to set up the entire tabular environment.
\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[ngerman]{babel}
\usepackage{array,calc}
\newlength\lena \newlength\lenb \newlength\lenc
\settowidth{\lenb}{100BASE-TX}
\setlength{\lena}{\dimexpr0.5\lenb-\tabcolsep-\arrayrulewidth/2\relax}
\setlength{\lenc}{\dimexpr1.5\lenb+\tabcolsep+\arrayrulewidth/2\relax}
\newcolumntype{P}[1]{>{\centering\arraybackslash}p{#1}} % centered "p" column
\newcommand\mcii[1]{\multicolumn{2}{P{\lenb}|}{#1}} % handy shortcut macros
\newcommand\mciii[1]{\multicolumn{3}{P{\lenc}|}{#1}}
\begin{document}
\begin{table}[ht!]
\setlength\extrarowheight{2pt}
\centering
\begin{tabular}{|l|*{6}{p{\lena}|}}
\hline
OSI-Schicht & \multicolumn{6}{c|}{Umsetzung}\\
\hline\hline
Anwendungsschicht & \mcii{} & \mcii{} & \mcii{} \\
\cline{1-1}
Darstellungsschicht & \mcii{SOME/I} & \mcii{AVB/TSN} & \mcii{DoIP} \\
\cline{1-1}
Sitzungsschicht & \mcii{} & \mcii{} & \mcii{} \\
\hline
Transportschicht & \mciii{TCP} & \mciii{UDP} \\
\hline
Vermittlungsschicht & \mciii{IPv4} & \mciii{IPv6} \\
\hline
Sicherungsschicht & \multicolumn{6}{c|}{Ethernet} \\
\hline
Bitübertragungsschicht & \mcii{100BASE-TX} & \mcii{100BASE-T} & \mcii{1000BASE-T} \\
\hline
\end{tabular}
\end{table}
\end{document}
• This is exactly what I needed! Thanks a lot! Mar 3 '17 at 13:18
\documentclass[a4paper]{article}
\usepackage{array}
\begin{document}
\newcolumntype{C}[1]{>{\centering\arraybackslash}p{#1}}
\begin{tabular}{|*6{C{2cm}|}} \hline
\multicolumn{2}{|C{4cm}}{b} & \multicolumn{2}{|C{4cm}}{c} & \multicolumn{2}{|C{4cm}|}{d} \\ \hline
\multicolumn{3}{|C{6cm}}{f} & \multicolumn{3}{|C{6cm}|}{g} \\ \hline
\end{tabular}
\end{document}
Another flexible approach using \tabularx with two \newcommands for convenience:
\newcommand{\row}[2]{%
\begin{tabularx}{\textwidth}{|X|X|}
#1
\end{tabularx}
}
\newcommand{\rrow}[3]{%
\begin{tabularx}{\textwidth}{|X|X|X|}
#1
\end{tabularx}
}
\begin{tabular}{@{}c@{}}\hline
\rrow{Long text here to test text wrapping in cells}{Long text here to test text wrapping in cells}{Long text here to test text wrapping in cells}\\\hline
\row{Long text here to test text wrapping in cells}{Long text here to test text wrapping in cells}\\\hline
\end{tabular}
Building on the above, here is a complete solution:
\documentclass[a4paper]{article}
\usepackage{tabularx,array,multirow}
\begin{document}
\newcolumntype{C}{>{\centering\arraybackslash}X}
\newcommand{\xtab}[1]{%
\begin{tabularx}{.7\textwidth}{C}
#1
\end{tabularx}
}
\newcommand{\xxtab}[2]{%
\begin{tabularx}{.7\textwidth}{C|C}
#1
\end{tabularx}
}
\newcommand{\xxxtab}[3]{%
\begin{tabularx}{.7\textwidth}{C|C|C}
#1
\end{tabularx}
}
\begin{tabular}{|l|c|}
\hline
OSI-Schicht & \xtab{Umsetzung} \\ \hline
Anwendungsschicht & \\ \hline
Darstellungsschicht & \xxxtab{ SOME/IP }{ AVB/TSN}{ DoIP } \\ \hline
Sitzungsschicht & \\ \hline
Transportschicht & \xxtab{TCP} {UDP} \\ \hline
Vermittlungsschicht & \xxtab{IPv4} {IPv6} \\ \hline
Sicherungsschicht & \xtab{Ethernet} \\ \hline
Bitübertragungsschicht & \xxxtab{100BASE-TX} {100BASE-T1} {100BASE-T} \\ \hline
\end{tabular}
\end{document}
This is very easy in ConTeXt MKIV with Natural Tables.
\starttext
\startTABLE
\NC[nx=2] b \NC[nx=2] c \NC[nx=2] d \NC\NR
\NC[nx=3] f \NC[nx=3] g \NC\NR
\stopTABLE
\stoptext
|
2021-12-06 02:50:34
|
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|
https://math.stackexchange.com/questions/1506552/how-to-prove-that-there-either-exist-h-2-h-1-cong-k-2-k-1-or-h-2-h-1-cong-m-2/1507559
|
# How to prove that there either exist $H_2/H_1\cong K_2/K_1$ or $H_2/H_1\cong M_2/M_1$
Suppose I have a group G , and N is a normal subgroup of G. Then, suppose we have subgroups $H_{1}$ and $H_{2}$ of G such that $H_{1}$ is a normal subgroup pf $H_2$. Also, $H_2/H_1$ is a simple sub-quotient group of G(which means $H_2/H_1$ is just a simple group).
Then,prove that either we can find a simple subquotient group $K_2/K_1$ of N($K_2$ and $K_1$ are subgroups of N, and $K_1$ is a normal subgroup pf $K_2$) such that $H_2/H_1\cong K_2/K_1$, or we can find a simple sub-quotient group $M_2/M_1$ of group $G/N$ such that $H_2/H_1\cong M_2/M_1$($M_1$ is a normal subgroup of $M_2$, and $M_1,M_2$ are sungroups of G/N)
I think, if $H_2 \subset N$, then we are done since $H_1,H_2$ are subgroups of N. Similarly, if $H_1\supset N$, then we are also done, since $H_2/H_1\cong (H_2/N)/(H_1/N)$ and ($H_2/N),(H_1/N)$ are subgroups of G/N. But, now I do not know how to contonue to prove this question. Can someone help me solve this question?
First suppose $H_1\cap N\ne H_2\cap N$ then $K=H_2\cap N/H_1\cap N$ is a subquotient group of $N$.
If $K$ is not simple, then there exists a proper subgroup $S$ of $H_2\cap N$ that properly contains $H_1\cap N$. Notice $H_1\subseteq S+H_1\subseteq H_2$. From the definition of $S$, $(S+H_1)\cap N=S\ne H_1\cap N$ so $S+H_1\ne H_1$. Similarly $S+H_1\ne H_2$. But this means $H_2/H_1$ is not simple, so by contradiction $K$ is simple. $H_1\cap N$ is normal in $H_2\cap N$ follows easily from $N$ being normal in $G$ and $H_1$ being normal in $H_2$.
Now suppose $H_1\cap N=H_2\cap N$, then $M=(H_2N/N)/(H_1N/N)$ is a subquotient group of $G/N$ (again, normality follows easily from normality of $N$ in $G$ and $H_1$ in $H_2$).
By the second isomorphism theorem $H_2N/N\cong H_2/(H_2\cap N)$ and $H_1N/N\cong H_1/(H_1\cap N)$ but $H_1\cap N=H_2\cap N$ by assumption, so we get by the third isomorphism theorem $M\cong (H_2/(H_1\cap N))/(H_1/(H_1\cap N))\cong H_2/H_1$ so $M$ is simple.
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2020-01-19 10:34:06
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http://mathhelpforum.com/advanced-algebra/108017-isomorphism.html
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# Math Help - Isomorphism
1. ## Isomorphism
Let G be the group of all real-valued functions on the unit interval [0,1], where we define for f,g elements of G, addition by (f + g)(x) = f(x) + g(x) for every x elements of [0,1]. If N = { f element of G,f(1/4) = 0 }, prove that G/N is ismorphic to real numbers under addition
2. Originally Posted by Godisgood
Let G be the group of all real-valued functions on the unit interval [0,1], where we define for f,g elements of G, addition by (f + g)(x) = f(x) + g(x) for every x elements of [0,1]. If N = { f element of G,f(1/4) = 0 }, prove that G/N is ismorphic to real numbers under addition
What about H: G --> R+ defined by H(f):= f(1/4)? Can you prove this is a homom. of groups and it is onto? Then use the first isomorphism theorem.
Tonio
3. Originally Posted by tonio
What about H: G --> R+ defined by H(f):= f(1/4)? Can you prove this is a homom. of groups and it is onto? Then use the first isomorphism theorem.
Tonio
Thanks
4. Originally Posted by Godisgood
Thanks but am still not able to prove is homomorphism and onto?Can u pls show me how to dat that..
Hmm....to study this stuff you must have taken before at least an introductory calculuis course and even a little more, and linear algebra and stuff...
Is is true that H(f + g) = H(f) + H(g)? Or what is the same, is it true that (f + g)(1/4) = f(1/4) + g(1/4)? To answer this just check CAREFULLY the definition of addition in G...
About onto: is it true that for any real number r we can find a real valued function defined on [0,1] s.t. f(1/4) = r?
Please do think a little about these questions and make an effort towards their solution, and THEN if you're still stuck write back.
Tonio
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2014-09-22 03:05:44
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https://bestpythonide.com/p/CamDavidsonPilon-Probabilistic-Programming-and-Bayesian-Methods-for-Hackers-python-deep-learning
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# Bayesian Methods for Hackers
#### Using Python and PyMC
The Bayesian method is the natural approach to inference, yet it is hidden from readers behind chapters of slow, mathematical analysis. The typical text on Bayesian inference involves two to three chapters on probability theory, then enters what Bayesian inference is. Unfortunately, due to mathematical intractability of most Bayesian models, the reader is only shown simple, artificial examples. This can leave the user with a so-what feeling about Bayesian inference. In fact, this was the author's own prior opinion.
After some recent success of Bayesian methods in machine-learning competitions, I decided to investigate the subject again. Even with my mathematical background, it took me three straight-days of reading examples and trying to put the pieces together to understand the methods. There was simply not enough literature bridging theory to practice. The problem with my misunderstanding was the disconnect between Bayesian mathematics and probabilistic programming. That being said, I suffered then so the reader would not have to now. This book attempts to bridge the gap.
If Bayesian inference is the destination, then mathematical analysis is a particular path towards it. On the other hand, computing power is cheap enough that we can afford to take an alternate route via probabilistic programming. The latter path is much more useful, as it denies the necessity of mathematical intervention at each step, that is, we remove often-intractable mathematical analysis as a prerequisite to Bayesian inference. Simply put, this latter computational path proceeds via small intermediate jumps from beginning to end, where as the first path proceeds by enormous leaps, often landing far away from our target. Furthermore, without a strong mathematical background, the analysis required by the first path cannot even take place.
Bayesian Methods for Hackers is designed as an introduction to Bayesian inference from a computational/understanding-first, and mathematics-second, point of view. Of course as an introductory book, we can only leave it at that: an introductory book. For the mathematically trained, they may cure the curiosity this text generates with other texts designed with mathematical analysis in mind. For the enthusiast with less mathematical background, or one who is not interested in the mathematics but simply the practice of Bayesian methods, this text should be sufficient and entertaining.
The choice of PyMC as the probabilistic programming language is two-fold. As of this writing, there is currently no central resource for examples and explanations in the PyMC universe. The official documentation assumes prior knowledge of Bayesian inference and probabilistic programming. We hope this book encourages users at every level to look at PyMC. Secondly, with recent core developments and popularity of the scientific stack in Python, PyMC is likely to become a core component soon enough.
PyMC does have dependencies to run, namely NumPy and (optionally) SciPy. To not limit the user, the examples in this book will rely only on PyMC, NumPy, SciPy and Matplotlib.
Bayesian Methods for Hackers is now available as a printed book! You can pick up a copy on Amazon. What are the differences between the online version and the printed version?
• Additional Chapter on Bayesian A/B testing
• Updated examples
• Answers to the end of chapter questions
## Contents
See the project homepage here for examples, too.
The below chapters are rendered via the nbviewer at nbviewer.jupyter.org/, and is read-only and rendered in real-time. Interactive notebooks + examples can be downloaded by cloning!
### PyMC2
• Prologue: Why we do it.
• Chapter 1: Introduction to Bayesian Methods Introduction to the philosophy and practice of Bayesian methods and answering the question, "What is probabilistic programming?" Examples include:
• Inferring human behaviour changes from text message rates
• Chapter 2: A little more on PyMC We explore modeling Bayesian problems using Python's PyMC library through examples. How do we create Bayesian models? Examples include:
• Detecting the frequency of cheating students, while avoiding liars
• Calculating probabilities of the Challenger space-shuttle disaster
• Chapter 3: Opening the Black Box of MCMC We discuss how MCMC operates and diagnostic tools. Examples include:
• Bayesian clustering with mixture models
• Chapter 4: The Greatest Theorem Never Told We explore an incredibly useful, and dangerous, theorem: The Law of Large Numbers. Examples include:
• Exploring a Kaggle dataset and the pitfalls of naive analysis
• How to sort Reddit comments from best to worst (not as easy as you think)
• Chapter 5: Would you rather lose an arm or a leg? The introduction of loss functions and their (awesome) use in Bayesian methods. Examples include:
• Solving the Price is Right's Showdown
• Optimizing financial predictions
• Winning solution to the Kaggle Dark World's competition
• Chapter 6: Getting our prior-ities straight Probably the most important chapter. We draw on expert opinions to answer questions. Examples include:
• Multi-Armed Bandits and the Bayesian Bandit solution.
• What is the relationship between data sample size and prior?
• Estimating financial unknowns using expert priors
We explore useful tips to be objective in analysis as well as common pitfalls of priors.
### PyMC3
• Prologue: Why we do it.
• Chapter 1: Introduction to Bayesian Methods Introduction to the philosophy and practice of Bayesian methods and answering the question, "What is probabilistic programming?" Examples include:
• Inferring human behaviour changes from text message rates
• Chapter 2: A little more on PyMC We explore modeling Bayesian problems using Python's PyMC library through examples. How do we create Bayesian models? Examples include:
• Detecting the frequency of cheating students, while avoiding liars
• Calculating probabilities of the Challenger space-shuttle disaster
• Chapter 3: Opening the Black Box of MCMC We discuss how MCMC operates and diagnostic tools. Examples include:
• Bayesian clustering with mixture models
• Chapter 4: The Greatest Theorem Never Told We explore an incredibly useful, and dangerous, theorem: The Law of Large Numbers. Examples include:
• Exploring a Kaggle dataset and the pitfalls of naive analysis
• How to sort Reddit comments from best to worst (not as easy as you think)
• Chapter 5: Would you rather lose an arm or a leg? The introduction of loss functions and their (awesome) use in Bayesian methods. Examples include:
• Solving the Price is Right's Showdown
• Optimizing financial predictions
• Winning solution to the Kaggle Dark World's competition
• Chapter 6: Getting our prior-ities straight Probably the most important chapter. We draw on expert opinions to answer questions. Examples include:
• Multi-Armed Bandits and the Bayesian Bandit solution.
• What is the relationship between data sample size and prior?
• Estimating financial unknowns using expert priors
We explore useful tips to be objective in analysis as well as common pitfalls of priors.
More questions about PyMC? Please post your modeling, convergence, or any other PyMC question on cross-validated, the statistics stack-exchange.
## Using the book
The book can be read in three different ways, starting from most recommended to least recommended:
1. The most recommended option is to clone the repository to download the .ipynb files to your local machine. If you have Jupyter installed, you can view the chapters in your browser plus edit and run the code provided (and try some practice questions). This is the preferred option to read this book, though it comes with some dependencies.
• Jupyter is a requirement to view the ipynb files. It can be downloaded here. Jupyter notebooks can be run by (your-virtualenv) ~/path/to/the/book/Chapter1_Introduction $jupyter notebook • For Linux users, you should not have a problem installing NumPy, SciPy, Matplotlib and PyMC. For Windows users, check out pre-compiled versions if you have difficulty. • In the styles/ directory are a number of files (.matplotlirc) that used to make things pretty. These are not only designed for the book, but they offer many improvements over the default settings of matplotlib. 2. The second, preferred, option is to use the nbviewer.jupyter.org site, which display Jupyter notebooks in the browser (example). The contents are updated synchronously as commits are made to the book. You can use the Contents section above to link to the chapters. 3. PDFs are the least-preferred method to read the book, as PDFs are static and non-interactive. If PDFs are desired, they can be created dynamically using the nbconvert utility. ## Installation and configuration If you would like to run the Jupyter notebooks locally, (option 1. above), you'll need to install the following: • Jupyter is a requirement to view the ipynb files. It can be downloaded here • Necessary packages are PyMC, NumPy, SciPy and Matplotlib. • New to Python or Jupyter, and help with the namespaces? Check out this answer. • In the styles/ directory are a number of files that are customized for the notebook. These are not only designed for the book, but they offer many improvements over the default settings of matplotlib and the Jupyter notebook. The in notebook style has not been finalized yet. ## Development This book has an unusual development design. The content is open-sourced, meaning anyone can be an author. Authors submit content or revisions using the GitHub interface. ### How to contribute #### What to contribute? • The current chapter list is not finalized. If you see something that is missing (MCMC, MAP, Bayesian networks, good prior choices, Potential classes etc.), feel free to start there. • Cleaning up Python code and making code more PyMC-esque • Giving better explanations • Spelling/grammar mistakes • Suggestions • Contributing to the Jupyter notebook styles #### Commiting • All commits are welcome, even if they are minor ;) • If you are unfamiliar with Github, you can email me contributions to the email below. ## Reviews these are satirical, but real "No, but it looks good" - John D. Cook "I ... read this book ... I like it!" - Andrew Gelman "This book is a godsend, and a direct refutation to that 'hmph! you don't know maths, piss off!' school of thought... The publishing model is so unusual. Not only is it open source but it relies on pull requests from anyone in order to progress the book. This is ingenious and heartening" - excited Reddit user ## Contributions and Thanks Thanks to all our contributing authors, including (in chronological order): We would like to thank the Python community for building an amazing architecture. We would like to thank the statistics community for building an amazing architecture. Similarly, the book is only possible because of the PyMC library. A big thanks to the core devs of PyMC: Chris Fonnesbeck, Anand Patil, David Huard and John Salvatier. One final thanks. This book was generated by Jupyter Notebook, a wonderful tool for developing in Python. We thank the IPython/Jupyter community for developing the Notebook interface. All Jupyter notebook files are available for download on the GitHub repository. #### Contact Contact the main author, Cam Davidson-Pilon at [email protected] or @cmrndp ###### Owner ###### Cameron Davidson-Pilon Focusing on sustainable food. Former Director of Data Science @Shopify. Author of Bayesian Methods for Hackers and DataOrigami. ##### Comments • #### Port to PyMC3 Following the discussion in #155 , I decided to open a new issue to track progress on PyMC3 port. pymc3 branch last commit is really old now (Feb 2014) and rebasing notebook files is a nightmare ! So I created a new branch on my fork new-pymc3. ## PyMC3 port • [x] : Chapter 1 • [x] : SMS example • [ ] : Chapter 2 • [ ] : A little more on PyMC • [ ] : Modeling approaches • [ ] : An algorithm for human deceit • [ ] : Chapter 3 • [ ] : Opening the black box of MCMC • [ ] : Diagnosing Convergence • [ ] : Useful tips for MCMC • [ ] : Chapter 4 (to be detailed) • [ ] : The greatest theorem never told • [ ] : The Disorder of Small Numbers • [ ] : Chapter 5 (to be detailed) Loss Functions • [ ] : Machine Learning via Bayesian Methods • [ ] : Chapter 6 (to be detailed) • [ ] : Useful priors to know about • [ ] : Eliciting expert prior • [ ] : Effect of the prior as$N\$ increases
• [ ] : Bayesian Rugby
## Minor things
• [X] : Update requirements
• [X] : convert .ipynb to Notebook v4
• [X] : replace last cell by %run "../styles/setup.py" at the beginning
## Contribute
Anyone who want to contribute should pull new-pymc3, make changes and ask me to give them write permissions on my fork. So the progress can be easy followed here.
If you don't know how to contribute you can search in the repo some tasks : git grep TODO
• #### Enhancing the notebooks with dynamic UIs
Note: the dynamic notebooks live Here
Hi cameron,
I released Exhibitionist about 2 weeks ago. It's a python library for building dynamic HTML/UI views on top of live python objects in interactive python work. That's practically synonymous with ipnb today.
Since then, I've been looking for a way to showcase the library and what's possible with it. I'd like to take your notebooks and use Exhibitionist to integrate interactive UI's (dynamic plots, etc') so that readers can interact in realtime with the concepts.
I've already implemented the first view, allowing the user to visualize the exponential distribution while varying λ by using a slider. Here's a snapshot:
I'll be working on this in the coming weeks, how would you feel about having this live in a fork under @Exhibitionist. Would that be ok?
• #### Bandit example stopped working
In Chapter 6 the interactive bandits example does not work anymore. The buttons are displayed, but the bar charts and pdf plots are not shown.
Just looking over the code the problem could be in these lines:
<div id="paired-bar-chart" style="width: 600px; margin: auto;"> </div>
<div id="beta-graphs" style="width: 600px; margin-left:125px; "> </div>
The same is true for the solo BanditsD3.html file.
• #### Added Tensorflow Probability Example
This new added Jupyter Notebook does away with mentions of PyMC2, PyMC3, and Theano, and uses Google's Tensorflow probability for solving the same problems with the same concepts. There have also been increases to the resolutions of the matplotlib plots to show more detail on retina screens.
## In[8] with model: mu, sds, elbo = pm.variational.advi(n=50000) step = pm.NUTS(scaling=model.dict_to_array(sds), is_cov=True) trace = pm.sample(5000, step=step, start=mu) Out
AttributeError Traceback (most recent call last) in () 3 4 with model: ----> 5 mu, sds, elbo = pm.variational.advi(n=50000) 6 step = pm.NUTS(scaling=model.dict_to_array(sds), is_cov=True) 7 trace = pm.sample(5000, step=step, start=mu)
AttributeError: module 'pymc3.variational' has no attribute 'advi'
pymc3: 3.4.1-py36_0
• #### Chapter 6: Mean-Variance Optimisation Loss Function
Hi Cam,
Could you explain how to use (or reference to a source) this loss function:
I'm assuming that the loss function is attempting to minimise the portfolio weights for the 4 stocks (which can be done using scipy optimise etc.), but I'm not sure what the lambda parameter is.
Thanks!
• #### PDF documentation
The front readme says: PDF versions are available! Look in the PDF/ directory. but that directory does not exist anymore in the repository.
How can I most easily generate a PDF for latest version of the document? It is helpful to have a PDF of the book, so that it can be read on iPad, ebook readers, etc.
• #### Port code to PyMC3
PyMC3 is coming along quite nicely and is a major improvement upon pymc 2. I thus think a port of PPfH to PyMC3 would be very useful, especially since pymc3 is not well documented yet. All examples should be easy to port.
I don't think such a PR should be merged into master as pymc 2 is probably still around to stay and much more stable. But having a forked book would be quite nice. Certainly this point is up for debate.
• #### Added Chapter 4 in Tensorflow Probability
Added a notebook with a complete rewrite of Chapter 4 using Tensorflow Probability instead of Pymc3 or pymc2. Also reduced the amount of numpy and scipy usage.
• #### Matplotlib styles
Hi,
The plots in the notebooks rely on a custom matplotlibrc for visual style, Users who do share the same matplotlubrc can't reproduce the graphs, in terms of visual style, as that information is not part of the notebook.
To make it worse, the default style is horrible:
fyi.
• #### Ch 1: off by 1 error between pymc2 and 3
I absolutely love this project, and my team is now using it as a professional development module. We're using pymc3, and got a little puzzled by the last exercise in Ch 1 which asks you to "consider all instances where tau_samples < 45" as all of our values of tau are less than 45. Comparing the pymc2 and pymc3 versions the max value of tau is 45 in 2 and 44 in 3, with the distributions appearing the same other than being shifted by 1. Changing the >= to a > in the line lambda_ = pm.math.switch(tau >= idx, lambda_1, lambda_2) in the pymc3 version brings them back into alignment.
Both versions state tau like this:
tau = pm.DiscreteUniform("tau", lower=0, upper=n_count_data)
n_count_data is 74, so tau can have any integer value 0-74 inclusive. To reason about this it helps to think of the values of tau as representing the boundaries between the days and not the days themselves, so there is always going to be one more than there are days.
The pymc2 version sets up lambda_ like this:
@pm.deterministic
def lambda_(tau=tau, lambda_1=lambda_1, lambda_2=lambda_2):
out = np.zeros(n_count_data)
out[:tau] = lambda_1 # lambda before tau is lambda1
out[tau:] = lambda_2 # lambda after (and including) tau is lambda2
return out
While pymc3 does this:
with model:
idx = np.arange(n_count_data) # Index
lambda_ = pm.math.switch(tau >= idx, lambda_1, lambda_2)
So when tau is zero, the pymc2 version executes out[:0] which returns an empty array. In real world terms, this is the case where all events happened under the lambda_2 regime. pymc3 by contrast executes pm.math.switch(0 >= idx, lambda_1, lambda_2) and returns lambda_1 for the first element of idx because 0 >= 0 is True. The comparison operator needs to be > so that you can evaluate 0 > 0 and get False for that and all other elements of idx for the case where you're always in the lambda_2 regime.
I think I have all this right, but I'm a bit new to all of this so I wanted to lay out the reasoning before I put in a random PR to change a >= to a >. Thanks for reading, and let me know if this all makes sense.
• #### Chapter 6: Bayesian Multi-armed Bandits Code
After carefully studying the example code for the multi-armed bandit on chapter six, I found a piece of code which I believe is missing a parameter:
def sample_bandits(self, n=1):
bb_score = np.zeros(n)
choices = np.zeros(n)
for k in range(n):
#sample from the bandits's priors, and select the largest sample
choice = np.argmax(np.random.beta(1 + self.wins, 1 + self.trials - self.wins))
#sample the chosen bandit
result = self.bandits.pull(choice)
Here, np.random.beta(1 + self.wins, 1 + self.trials - self.wins) is missing the size parameter, thus it returns a single value, not an array. That makes np.argmax() to pick a bandit useless, as that will always return 0.
Shouldn't the code be np.random.beta(1 + self.wins, 1 + self.trials - self.wins, len(self.n_bandits)) ?
• #### Chapter 3 minor question
I have a minor question at Chapter 3.
Why probability of belonging to cluster 1 was calculated as the following [Figure 1] rather than this?
v = (1 - p_trace) * norm_pdf(x, loc=center_trace[:, 1], scale=std_trace[:, 1]) >
p_trace * norm_pdf(x, loc=center_trace[:, 0], scale=std_trace[:, 0])
[Figure 1]
Thank you for your wonderful book!
• #### Chapter 2: description regarding the separation plot for Fig. 2.3.2
"The black vertical line is the expected number of defects we should observe, given this model. This allows the user to see how the total number of events predicted by the model compares to the actual number of events in the data." The above ordinates form the paragraph under the first separation plot https://github.com/CamDavidsonPilon/Probabilistic-Programming-and-Bayesian-Methods-for-Hackers/blob/master/Chapter2_MorePyMC/Ch2_MorePyMC_PyMC2.ipynb However, I suppose there might be some misunderstandings: the expected number of defects should be computed by the approach explained in Appendix 2.5, i.e. posterior_probability.sum() in my case, it's about 6.99753 which corresponds to the number of the realized defect 7. However, what you computed within separation_plot.py is N - \sum_i p_i , in my case, it about 16.0047. In my opinion, this makes sense to show how far the blue bar the blue bars should distribute. As you explained in the text: Ideally, all the blue bars should be close to the right-hand side.
But, the description at the beginning of this issue, as I mentioned above, is not exact anymore. Maybe, we could say: The black vertical line is the expected number of defects (counting from right-hand side)
Best wishes,
Beinstein.
• #### Chapter 2 -- tfp.bijectors.AffineScalar is deprecated
Executing the code for the model in the Challenger Space Shuttle Disaster example, it returns an AttributeError, roughly "tfp.bijectors has no attribute AffineScalar". After an unusually long search in the internet, I found that, as per this source (https://github.com/tensorflow/probability/releases), this attribute is indeed deprecated. The release said to use tfp.Shift(shift) or tfp.Scale(scale), instead. Since the code called for a multiplying factor, I substituted the line for tp.bijectors.Scale(100.). It worked fine.
• #### Chpt #6; Example stock returns: ystockquote is not working
I could not make ystockquote to work no matter what I tried. Instead I used yahoo's yfinance package which has a straightforward api. I'm recording the updated code here in case someone encounters the same problem.
import yfinance as yf import pandas as pd
n_observations = 100 # we will truncate the the most recent 100 days.
stocks = ["AAPL", "GOOG", "TSLA", "AMZN"]
enddate = "2022-02-19" startdate = "2021-07-01"
stock_closes = pd.DataFrame()
for stock in stocks: x = yf.download(stock, startdate, enddate) stock_closes[stock] = x['Close']
stock_closes stock_returns = stock_closes.pct_change().iloc[1:, :] stock_return = stock_returns.iloc[-n_observations:,:]
###### A pure PyTorch batched computation implementation of "CIF: Continuous Integrate-and-Fire for End-to-End Speech Recognition"
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###### [EMNLP 2021] MuVER: Improving First-Stage Entity Retrieval with Multi-View Entity Representations
MuVER This repo contains the code and pre-trained model for our EMNLP 2021 paper: MuVER: Improving First-Stage Entity Retrieval with Multi-View Entity
May 30, 2022
###### [CVPR'21] Projecting Your View Attentively: Monocular Road Scene Layout Estimation via Cross-view Transformation
Projecting Your View Attentively: Monocular Road Scene Layout Estimation via Cross-view Transformation Weixiang Yang, Qi Li, Wenxi Liu, Yuanlong Yu, Y
Sep 13, 2022
###### PanopticBEV - Bird's-Eye-View Panoptic Segmentation Using Monocular Frontal View Images
Bird's-Eye-View Panoptic Segmentation Using Monocular Frontal View Images This r
Sep 16, 2022
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2022-09-27 23:23:51
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http://www.physicsforums.com/showthread.php?t=109005
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What do you do if your exact equation isn't exact? and they give u an Integrating F
Hello everyone I understand how to solve exact equations, but what happens when they arnt' exact? I'm confused on what i'm suppose to do! Does anyone feel like explaning hte process to me, if given an integrating factor/> or give me a website? Here is my problem:
Check that the equation below is not exact but becomes exact when multiplied by the integrating factor.
Integrating Factor:
Solve the differential equation.
You can define the solution curve implicitly by a function in the form
?
Thank you!
PhysOrg.com science news on PhysOrg.com >> 'Whodunnit' of Irish potato famine solved>> The mammoth's lament: Study shows how cosmic impact sparked devastating climate change>> Curiosity Mars rover drills second rock target
Recognitions: Gold Member Science Advisor Staff Emeritus Do you understand what an "integrating factor" is? If a differential equation is not exact then there always exists some function f(x,y) so that multiplying the equation by it makes it exact. Unfortunately, it's most often very difficult (if not impossible) to find that integrating factor! In this case your equation is x2y3dx+ x(1+ y2)dy= 0. Yes, that is NOT exact because (x2y3)[sub]y[sub]= 3x[sup]2[sup]y2 which is not the same as (x(1+ y2))x= 1+y2. Fortunately, you were told that $\frac{1}{xy^3}$ is an integrating factor. That means that multiplying the equation by that: (1/xy2){x2y3dx+ x(1+y2)dy = ydx+ (1+y2)y2)dy= 0. Is that exact? It certainly should be! If it is exact can you solve it?
OOoo!!! Awesome, thanks alot IVEY as always! It worked great! I got:
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2013-05-21 23:05:33
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https://groupprops.subwiki.org/wiki/Projective_special_linear_group_equals_alternating_group_in_only_finitely_many_cases
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Projective special linear group equals alternating group in only finitely many cases
Statement
The following are the cases where a Projective special linear group (?) is isomorphic to an Alternating group (?):
1. $PSL(1,k)$ is isomorphic to the alternating group on one letter, and on two letters, for any field $k$.
2. $PSL(2,3)$ is isomorphic to the alternating group of degree four.
3. $PSL(2,4)$ and $PSL(2,5)$ are both isomorphic to the alternating group of degree five.
4. $PSL(2,9)$ is isomorphic to the alternating group of degree six.
5. $PSL(4,2)$ is isomorphic to the alternating group of degree eight.
Proof
The case of degree more than two
We first consider the case where $m \ge 3$. In this case, we prove that the only solution is $m = 4, q = 2, n = 8$.
The case of characteristic two
We now consider the case of fields of characteristic two. In this case, the group is:
$\! PSL(2,2^r)$
Its order is given by:
$\! (2^r + 1)2^r (2^r - 1)$.
For this to be isomorphic to the alternating group $A_n$, we must have:
$\! (2^r + 1)2^{r+1}(2^r - 1) = n!$.
Note that both $2^r + 1$ and $2^r - 1$ are both odd, so the largest power of $2$ dividing $n!$ is $r + 1$. This yields:
$\! r + 1 \le n - 1$.
Thus, $\! r \le n - 2$. We thus have:
$\! n! = 2^{r + 1} (2^{2r} - 1) \le 2^{n-1}(2^{2n - 4} - 1) \le 2^{3n - 5}$.
This puts a small bound on $n$, namely, $n \le 14$.as well as on $r$, namely $r \le 12$. A hand calculation shows that the only solutions are $r = 2, n = 5$ and $r = 3,n = 8$. A further check shows that in this case, the groups are indeed isomorphic.
The case of odd characteristic
We now consider the case of an odd prime, so the group is:
$\! PSL(2,p^r)$.
The order of the group is:
$\! p^r(p^r + 1)(p^r - 1)/2$.
For this to be isomorphic to the alternating group $A_n$, we get:
$\! p^r(p^r + 1)(p^r - 1) = n!$.
Clearly, $p^r + 1$ and $p^r - 1$ are relatively prime to $p$. Thus, the largest power of $p$ dividing $n!$ is $p^r$. This yields:
$r \le \frac{n}{p-1}$.
Thus, we get:
$n! \le p^{3n/(p-1)}$.
Note that since $\! p^{3/(p-1)} < 8$ for all primes $p$, we get:
$\! n! < 8^n$.
This puts a bound $n \le 19$. A hand calculation now yields that we have the following solutions:
• $\! n = 4, p = 3, r = 1$.
• $\! n = 5, p = 5, r = 1$.
• $\! n = 6, p = 3, r = 2$.
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2021-06-13 07:23:47
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https://www.sparrho.com/item/nonlocality-improves-deutsch-algorithm/95a8e7/
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# Nonlocality improves Deutsch algorithm
Research paper by Koji Nagata, Sangkyung Lee, Jaewook Ahn
Indexed on: 28 Nov '08Published on: 28 Nov '08Published in: Quantum Physics
#### Abstract
Recently, [{arXiv:0810.3134}] is accepted and published. We show that the Bell inequalities lead to a new type of linear-optical Deutsch algorithms. We have considered a use of entangled photon pairs to determine simultaneously and probabilistically two unknown functions. The usual Deutsch algorithm determines one unknown function and exhibits a two to one speed up in a certain computation on a quantum computer rather than on a classical computer. We found that the violation of Bell locality in the Hilbert space formalism of quantum theory predicts that the proposed {\it probabilistic} Deutsch algorithm for computing two unknown functions exhibits at least a $2\sqrt{2}(\simeq 2.83)$ to one speed up.
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2020-01-23 17:07:06
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https://frigidrain.gitbooks.io/interview-prep/content/more_problems.html
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# More Problems
### Kth Element*
Suppose we have a binary tree where each node contains a character and the same node can appear in more than one place. For example:
A
/ \
B B
/ \ / \
C D C D
Notice that even though B appears more than once, it is the same node so the subtree rooted at B is the same. Thus, we cannot have B as a parent of B. The following code finds the kth element that appears in a preorder traversal of the tree:
class TreeNode {
char val;
TreeNode left;
TreeNode right;
}
public String preorder(TreeNode node) {
if (node == null) {
return "";
}
return node.val + preorder(node.left) + preorder(node.right);
}
public char getk(TreeNode root, int k) {
return preorder(root).charAt(k);
}
1. What is the worst case time complexity of getk?
2. Write a more efficient implementation of getk.
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2018-03-20 05:57:42
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http://mathhelpforum.com/trigonometry/91584-help-finding-equation.html
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# Math Help - help finding an equation
1. ## help finding an equation for an ellipse
I'm having some problems with these exercise
find the equation of the ellipse with center at (3,1) , one vertex at (1,1) , passing through ( 2,1 + sqrt (3/2)).
2. the ellipse equation
$\frac{(x-h)^2}{a^2}+\frac{(y-k)^2}{b^2}=1$
$since...(h,k),,the...center...they...gave..you..th e..center$
you can find a with this statement "one vertex at (1,1)" and you know that the center is "(3,1)" when you find a and substitute a and the center in the equation then you have just one variable "b" you can find it try..
best wishes
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2015-11-30 12:42:39
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https://www.physicsforums.com/threads/how-to-find-composition-series-of-z_n-of-length-k.834805/
|
# How to find composition series of Z_n^* of length k?
1. Sep 27, 2015
### jackmell
Hi,
I'd like to find easily-accessible composition series of an interesting lengths say 10 or so (to study some theorems about subgroup series experimentally). I'm thinking the integer mod unit groups, that is
$\mathbb{Z}_n^*=Z_0\rhd Z_1\rhd Z_2\rhd \cdots \rhd Z_9\rhd Z_{10}=\{1\}$. Would this be a relatively simple set of groups to do so with?
That's seems an interesting question: What is the smallest $n$ such that $\mathbb{Z}_n^*$ has a composition series of length $10$? Or for that matter, what is the set of minimum such sizes for a range of $n$? I have no idea and to make matters worst, I do now know how to easily find the set $\{Z_i\}$ other than number-crunching or I guess figure out maybe how to do it in GAP.
Is there a standard way to find these series? May be a GAP command to do so. Don't know yet -- not an easy program to use I think.
Jack
Edit:
Ok just thought of something: A normal subgroup $K\lhd G$ is a maximal normal subgroup iff $G/K$ is simple. Ok then, they're all normal in $Z_n^*$ so then I guess just find the largest one in $Z_n^*$, then find the largest one in that one, largest one in that one and so on until I get to 1. Not sure GAP can handle this though for large groups.
. . . I'm thinking in the millions to get it to 10.
Here's a start:
Code (Text):
gap> DisplayCompositionSeries(Group((1,2,3,4,5,6,7,8,9,10),(1,2)));
G (2 gens, size 3628800)
| Z(2)
S (8 gens, size 1814400)
| A(10)
1 (0 gens, size 1)
I interpret that to mean: $S_{10}\rhd A_{10}\rhd \{1\}$ and I think in fact we can write $S_n\rhd A_n\rhd \{1\}$. Can't figure out how to code integer mod groups though.
Last edited: Sep 27, 2015
2. Sep 27, 2015
### mathwonk
I think the same set of notes I inked for you on finding all groups of small order also classifies in detail the decompostion of all groups of units mod n, as an interesting spoecial example of the theiorem on decomposing finite abelian groups. I'll try to find a page number. see pages 48-50 of these notesn for a product decomposition, which should yield what you want: (but I guess you still need to figure out how many prime factors p-1 has for p a given prime.)
http://alpha.math.uga.edu/~roy/844-2.pdf
Last edited: Sep 27, 2015
3. Sep 27, 2015
### jackmell
Thanks for that mathwonk. However, that reference refers to the decomposition of an integer mod group into it's p-sylow subgroups. I don't see how that's related to the composition series of a group. Take for example:
$\mathbb{Z}_{10!}^*\cong \mathbb{Z}_2\times \mathbb{Z}_2\times\mathbb{Z}_2\times \mathbb{Z}_{2^2}\times\mathbb{Z}_{2^6}\times \mathbb{Z}_3\times\mathbb{Z}_{3^3}\times \mathbb{Z}_{5}$
Now suppose I wanted to compute a (solvable) composition series for that group. Are you suggesting I can use it's decomposition into p-groups to obtain the composition series?
Last edited: Sep 27, 2015
4. Sep 27, 2015
### mathwonk
yes. it looks as if there would be a series of length 16. i.e. for an abelian group the factors of the composition series are all cyclic of prime order. right?
5. Sep 27, 2015
### jackmell
Ok thanks. Afraid I'm not seeing the connection between the p-group decomposition and the group's composition series. Perhaps if we take a smaller group. For example consider $\mathbb{Z}_{100}^*$.
Ok, now the divisors of this group are $1,2,4,5,10,20,25,50,100$ and then using the Theorem I quoted above about maximal normal subgroups $K$ inducing $G/K$ to be simple, then am I correct in saying a composition series for this group would be:
$Z_{100}^* \rhd H_{50} \rhd H_{25} \rhd H_5 \rhd \{1\}$
where the $H_x$ is some maximal (normal) subgroup of the one before it. Alright, now the p-group decomposition for the group is:
$\mathbb{Z}_{100}^*\cong \mathbb{Z}_2 \times \mathbb{Z}_{2^2} \times \mathbb{Z}_5$
How are these two related?
Edit: I made a mistake, the order of $\mathbb{Z}_{100}^*$ is 40 and the divisors of 40 are: $1,2,4,5,8,10,20,40$ so that I think I could write the composition series as:
$\mathbb{Z}_{100}^*\rhd H_{20} \rhd H_{10} \rhd H_{5}\rhd \{1\}$
Also, now I see I think where the prime order of the factors are coming from: in order for the factors $H_i/H_{i+1}$ to be simple, then necessarily, we must have that $|H_i/H_{i+1}|$ is prime (I think). And in the case I wrote above, indeed the factor sizes are 2,2, 2, and 5 (I think).
Last edited: Sep 27, 2015
6. Sep 27, 2015
### mathwonk
yes you are right. a composition series for Zp x Zq x Zr, where p,q,r are all prime, for example is Zp, ZpxZq, ZpxZqxZr, of length 3, the number of prime factors of the order of the group. so for abelian groups, the existence of a composition series, with unique quiotients,. is the world's hardest proof of unique prime factorization of integers.
7. Sep 28, 2015
### jackmell
Ok thanks. Think I figured out an example of a composition series of length 10: Note that $\mathbb{Z}_n^*$ is cyclic for powers of odd primes. Then consider $\mathbb{Z}_{3^{10}}^*=\mathbb{Z}_{59049}^*$ for which $2$ generates the group. Then I believe the following is a composition series for $\mathbb{Z}_{3^{10}}^*$:
$\mathbb{Z}_{3^{10}}^*=Z_0\rhd \big<2\big>\rhd \big<2^{3}\big>\rhd \big<2^{3^2}\big>\rhd\big<2^{3^3}\big>\cdots\rhd \big<2^{3^9}\big>\rhd \big<2^{3^{10}}\big>=\{1\}$
Pretty sure that's correct. But that's my reason for looking for one: now I can experiment with it and figure out why it is and why other properties of composition series are what they are. Working with an actual test case helps me understand the theory better. :)
Edit:
Wrong again: $|\mathbb{Z}_{3^{10}}^*|=39366$. I need to work on this -- will get back later when I figure it out.
Last edited: Sep 28, 2015
8. Sep 30, 2015
### jackmell
The group $\mathbb{Z}_{1024}^*$ I think is a small integer mod group with a composition series of length 10:
$\mathbb{Z}_{1024}^*\rhd \big<a^2\big>\rhd \big<a^4\big>\rhd \big<a^8\big>\rhd\cdots\rhd \big<a^{10}\big>=\{1\}$ where $a$ is any member of this cyclic group which generates the group.
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2017-12-11 23:42:11
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https://www.nature.com/articles/s41467-020-16331-4?error=cookies_not_supported
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## Introduction
Electron quantum optics1,2 is based on the profound analogy between the transport of single quasiparticles in a quantum coherent conductor and the propagation of single photons in a quantum optics setup. This has led to seminal electron interferometry experiments realized in edge channels (ECs) of the quantum Hall effect, whether in a Mach–Zehnder geometry3 or, recently, in a Hong–Ou–Mandel setup4 where two single-charge excitations emitted at a well-defined energy collide on a quantum point contact, probing their indistinguishable nature. The majority of these experiments have been performed at filling factor ν = 2 of the quantum Hall regime, where, for a given carrier density, the quantum Hall effect is the most stable. However, interactions between the two ECs of ν = 2 have been shown to lead to decoherence as well as energy relaxation. The latter corresponds to the fact that energy can be transferred from one EC to the next, even in the absence of tunneling between the two. This strongly challenges the simple picture of electron quantum optics, and raises the crucial question of the nature of the excitations that actually are interfering in the aforementioned experiments.
The first investigations of decoherence and energy relaxation at ν = 2 involved biased quantum point contacts to generate a broadband, out-of-equilibrium distribution function that was probed using Mach–Zehnder interferometry5,6,7,8,9 and energy spectroscopy10,11 techniques. From these works emerged a clearer picture of the role of interactions between copropagating ECs, which is well accounted for by a powerful theoretical description in terms of Tomonaga–Luttinger liquid (TLL) physics. In the so-called TLL model, interactions lead to new eigenstates of the system, which are not Fermionic, but charge- and dipole- (or spin-) like plasmons shared by the two ECs12,13,14,15. The decomposition of a Fermionic excitation in one EC onto the plasmon modes shared by the two ECs gives rise to energy relaxation and decoherence14,15,16. This model describes particularly well Hong–Ou–Mandel collision experiments using single excitations emitted at finite energy4,17,18,19.
Underlying the TLL model is the assumption that the interaction between the two ECs dwarfs all other energies. This means that although the energy of a carrier injected into one of the ECs will be redistributed between the two interacting ECs, the system will conserve its total energy. How valid this assumption is remains an important question, as a number of the basic predicted features of the evolution of a quasiparticle emitted at finite energy remain to be confirmed experimentally. The shape of the energy distribution of finite energy quasiparticles, which is referred to as the quasiparticle peak, has so far not been observed in the quantum Hall regime, nor has its evolution during propagation.
In fact, probing the quasiparticle peak is of crucial importance, since it would directly reflect the wavepackets of single particles that are manipulated in quantum optics, and its behavior could establish unambiguously characteristics specific to the TLL model. One such potential feature is the remarkable ability to partially regenerate the initial excitation16. This is analogous to Rabi oscillations, where a system oscillates between two states that are not proper eigenstates due to their mutual interaction. Specifically, the TLL predicted regeneration of an initial excitation comes about through the “catching up” and recombination of a fast-propagating charge plasmon with a slower dipole plasmon (animations illustrating the effect can be found in the Supplementary material of ref. 16). However, this resurgence has only been indirectly observed in Mach–Zehnder interferometry experiments with biased quantum point contacts5,7,20, whereas it should clearly appear as a revival of the quasiparticle peak at finite length and energy16. Furthermore, recent experiments using such finite energy quasiparticles in other schemes revealed important qualitative inconsistencies with the TLL model. First, spectroscopy experiments showed that a sizable portion of the energy injected in the system was lost to additional degrees of freedom, not included in the TLL model11. Second, finite energy excitations were shown to interfere within a Mach–Zehnder setup with a visibility that decreased, but remained finite even at high energy instead of fully vanishing as predicted21. Very recently, an experiment using an energy spectroscopy technique similar to the one reported in the present paper showed that quasiparticles can exchange energy between spatially distinct parts of the circuit22,23. While this result can explain the missing energy reported in ref. 11, it is again in contrast with the TLL model. This series of inconsistencies raises a crucial question: is there merely a missing ingredient in the TLL model for it to fully describe the physics of interacting ECs, or is it necessary to replace it with a different theory? Indeed, a recent competing theoretical description24 is qualitatively compatible with the early energy spectroscopy experiments10,11. Based on a Fermi liquid description of the ECs, and the assumption that electron–electron interactions do not conserve momentum, this model predicts that the quasiparticle peak gradually broadens and shifts towards lower energies while both ECs are warmed up. Contrary to double-step distribution functions obtained with a biased quantum point contact, which yield similar results within both models, the predicted behavior of finite energy quasiparticles is thus strikingly different, as the TLL model predicts the quasiparticle peak to diminish in amplitude, and then to revive, while its position and width remain constant.
To answer the above question, we have performed an experimental investigation of the energy relaxation of energy-resolved quasiparticles, showing a clear observation of the quasiparticle peak at ν = 2. We show that while the quasiparticle peak is strongly suppressed with the injection energy and the propagation length, it clearly undergoes a revival at intermediate energy and length before disappearing into a long-lived state that is not fully thermalized. The observed evolution of the quasiparticle peak allows us to unambiguously discriminate between the two models. We show that the TLL model can be refined in order to explain our results by including dissipation towards external degrees of freedom, and, by spatially separating the two ECs with an additional gate, we unambiguously demonstrate the role of EC coupling.
## Results
### Experimental approach
We have followed the approach proposed in refs. 24,25, and recently applied in ref. 22, in which one injects quasiparticles at a well-defined energy into an EC using a first quantum dot (QD) in the sequential tunneling regime. The injected quasiparticles then propagate over a finite length L, after which we perform a spectroscopy of the energy distribution function f(E) of the quasiparticles using a second downstream QD as energy filter. This spectroscopy technique combined with a quantum point contact to generate excitations was previously used in refs. 10,11,26,27. A very similar setup was used to investigate charge transfer processes between distant QDs in the absence of a magnetic field28; furthermore, a recent spectroscopy experiment showed that at vastly higher energies (in the 0.1 eV range), electrons in an EC decay by coupling to optical phonons29. It is also worth noting that other experimental techniques can be used to probe the energy distribution function, by measuring shot noise30, or by performing a quantum tomography of the excitation injected in the EC31,32,33,34. The latter is known for being among the most challenging experiments undertaken so far in electron quantum optics.
The devices’ geometry is depicted in Fig. 1a. The two chiral ECs of ν = 2 are depicted as orange lines. The QDs are defined electrostatically, and can be independently controlled using the plunger gate voltages VP1 and VP2. Both QDs are tuned to transmit only the outer EC. Quasiparticles in the outer EC stemming from the drain electrode are thus transmitted across the first dot QD1, and propagate along the outer EC connecting the first dot to the second dot QD2. A length gate, controlled by the voltage VL, is used to increase the propagation path by diverting the ECs around the square area delimited by black dashed lines in Fig. 1a (a 200 nm insulating layer of SU-8 resist separates the rest of the gate from the surface of the sample). Several samples have been measured; here we show results obtained on three different devices, with nominal propagation lengths L = 480 nm, L = 750 nm, and 3.4 μm. Using the length gate on the first two devices yields the additional lengths L ≈ 1.3 μm (long path for the L = 480 nm device) and L ≈ 2.17 μm (long path for the L = 750 nm device—see Supplementary Note 1 for details on the devices, including the estimation of the lengths). Figure 1b depicts the energy configuration of the two dots: a negative voltage VD is applied to the drain contact while the contacts connected to the ECs flowing between the two dots are grounded, defining the zero of energy in our experiment. A narrow single resonance of QD1 is tuned inside the transport window at an energy E1(VP1), defining the quasiparticle injection energy. We measure the transconductance ∂I2/∂VP2 of QD2 while sweeping the energy E2(VP2) of a narrow single resonance in this dot that defines the detection energy. A calibration of both QDs is performed to extract their respective lever arms, linking the plunger gates voltages VPi to the energies Ei (see Supplementary Note 2). This allows us, after compensating for the small crosstalks between the two plunger gates, to directly probe the dependence of ∂I2/∂VP2 with the detection energy E2 for different values of the injection energy E1. This signal is proportional to −∂(Δf(E))/∂E, where Δf(E) = f(E) − fS(E) is the difference of the energy distribution functions on either side of QD210,11,26,27, convoluted with the lineshape of the resonance of QD2 (fS(E) is the distribution function of the source EC). This convolution mostly affects the width of the features in the transconductance (see Supplementary Note 3). In the following, all widths discussed are convoluted widths. We separate the two contributions of f(E) and fS(E) by applying a positive voltage VS to the source contact. This is illustrated in Fig. 1c, which shows a typical measurement of ∂I2/∂VP2 as a function of E1 and E2, for L = 480 nm. The source and drain potentials, shown as thick arrows in Fig. 1c, are set to eVD ≈ −eVS ≈ 125 μeV, with e ≈ −1.6 × 10−19 C the electron charge. The three main features appearing on this map are (i) the blue (negative) vertical line at E2 = eVS ≈ −125 μeV, corresponding to ∂fS(E)/∂E, (ii) the red (positive) vertical line at E2 ≈ 0 μeV, corresponding to the low-energy part of ∂f(E)/∂E, and (iii) the oblique line following a y = x line (black dashed line), corresponding to the emitted quasiparticles, which are detected after their propagation. Note that no signature of Auger-like processes22 (which would appear as diagonal lines dispersing in a direction opposite to the black dashed line) has been identified in any of the transconductance maps we obtained. We integrate the transconductance so as to obtain the energy distribution function f(E), which we discuss in the rest of this paper.
### Measured distribution functions
Figure 2 shows measurements of f(E) for L = 480 nm (top panel) and L = 750 nm (bottom panel). The injection energy E1 is gradually increased from negative values (blue curves), where the resonance of QD1 is outside the bias window, to large positive values E1 > 100 μeV (red curves), where we expect to detect quasiparticles at high energy. The measured f(E) curves evolve from a Fermi function at low temperature (the apparent temperature is increased to ~40 mK by the convolution with the resonance of QD2, see Supplementary Note 3) to strongly out-of-equilibrium distribution functions showing a distinct quasiparticle peak at finite energy. This is particularly striking for the shortest distance (top panel), where the peak clearly appears even at the largest energy E1 = 173 μeV (note that the peak was not observed in ref. 22, where the propagation length was ~1.5 μm). The peak position increases linearly with E1, while its amplitude decreases. In contrast, for a path only 50% longer, the peak amplitude is strongly suppressed; however, after vanishing at E1 ~ 90 μeV, it reappears as E1 is further increased (see inset in the bottom panel of Fig. 2). The clear presence of a quasiparticle peak, its strong decay, and its subsequent revival at intermediate lengths are consistently observed in our experiment, and are the main results of this paper. In the following, we quantitatively analyze the measured f(E), and compare our results with the leading theories.
### Quasiparticle peak analysis
Figure 3 shows a semi-log scale plot of the data shown in Fig. 2, illustrating our analysis. For L = 480 nm (Fig. 3a), the quasiparticle peak is well fitted by a Lorentzian peak without any offset, shown as dashed black lines. Remarkably, the energy position Epeak of the peak matches the injection energy E1, and its full-width at half-maximum remains constant as E1 is increased (see inset in Fig. 3a). This observation, which was consistent in all data where the quasiparticle peak is distinguishable, is in direct contradiction with the predictions of Lunde and Nigg24, but in agreement with the TLL model. Furthermore, the semi-log scale shows that the maximum of the quasiparticle peak follows an exponential decay (gray dashed line) over more than an order of magnitude. For L = 750 nm (Fig. 3b), the peak is strongly suppressed. However, while the peak only shows up as a faint bump at low E1 and has vanished for intermediate E1, it appears clearly at large E1, and can again be fitted by a Lorentzian with preserved width and position. In addition, the peak height increases with the injection energy, as seen in Fig. 2. We observed the revival in several realizations of the experiment in the same L = 750 nm device, with different gating conditions, and during different cooldowns (note that while we did not observe the revival for L = 480 nm, we show below that it is expected to occur at significantly higher E1, outside our spectroscopy range—see “Methods”). While those observations clearly are characteristic features of the TLL model, it is not the case for the apparent exponential decay of the peak at L = 480 nm. Another discrepancy is the fact that the low-energy part of distribution functions, away from the quasiparticle peak, seem to be (at least to some extent) independent of the injection energy, whereas it should become broader with increasing E1. This strongly suggests that dissipation—that is, loss of energy towards other degrees of freedom than the plasmon modes—needs to be taken into account. The presence of dissipation was already identified in previous works11,35, and particularly in ref. 22, where it manifested as long-distance Auger-like processes.
### Modeling dissipation in the TLL model
A simple way to include dissipation in the TLL model (see Supplementary Note 8 for details of the model) consists in introducing an ad hoc linear friction term in the equations of motion for the bosonic fields describing the charge and dipole plasmon modes13,14,16,36. Because of interactions, assumed here to be short-ranged, these modes are shared by the two ECs, and their respective velocities vρ (charge mode) and vσ (dipole mode) depend on the Fermi velocities v1, v2 in each EC in the absence of interactions, as well as on the coupling u between the ECs. These parameters combine into an effective mixing angle θ, defined as $$\tan (2\theta )=2u/({v}_{1}-{v}_{2})=2u/{v}_{2}(\alpha -1)$$, which is zero when the two ECs do not mix, and π/4 for maximal coupling. This reflects the fact that even if the interaction u is small, the ECs can become maximally coupled if they propagate at exactly the same velocity. In this strong coupling limit, and in the absence of dissipation, the quasiparticle peak height is given by a characteristic squared Bessel function $${J}_{0}^{2}(2.5\times {E}_{1}/{E}_{0})$$, with E0 = 5vρvσ/L(vρ − vσ) ≈ 5vσ/L14,16. Its oscillatory behavior corresponds to the revival phenomenon, with the first zero occurring at E0. Tuning θ away from the strong coupling value modifies the Bessel function profile, leading to a lifting up of the zeros. When one includes dissipation, expressions for the quasiparticle peak height are modified, and acquire an exponentially decaying prefactor $$\sim \exp (-{E}_{1}/{E}_{\gamma })=\exp (-2{\gamma }_{0}{E}_{1}L/\hslash {v}_{\rho })$$, where γ0 is the friction coefficient. Note that the model can be further refined by, for example, considering non-linear plasmon dispersion37,38, or long-range interactions35.
Figure 4 shows how this model compares to our data at L = 480 and 750 nm. We plot the extracted Lorentzian peak heights from the 480 nm data shown in Fig. 3a (green pentagons), as well as for data obtained using a different resonance of QD1 in the same device (black hexagons), versus injection energy E1. Data are normalized by the calibrated transmission of QD1, corresponding to the expected height of the injected peak (see Supplementary Note 1). The exponential decay observed in Fig. 3 is well reproduced by our model (thick green and gray lines). The TLL fits parameters v2, α, θ, and γ0, as well as corresponding plasmon velocities vρ, vσ and the characteristic energies E0 and Eγ are summed up in Table 1. In particular, the values of the revival energy E0 obtained for the 480 nm sample are much larger than our maximum spectroscopy range ~ 200 μeV, explaining why the revival is not observed in that sample. We also plot in Fig. 4 the peak height for two different datasets of the L = 750 nm device. The blue symbols (labeled cooldown 1) correspond to the data shown in Figs. 2 and 3b. The red symbols correspond to data obtained in a subsequent cooldown of the device, also showing the revival (see Supplementary Note 5 for additional data and analysis), despite having a different electrostatic environment due to thermal cycling. Importantly, this demonstrates that the observed revival is a robust phenomenon, unlikely to stem from a spurious mesoscopic effect (such as an impurity along the propagation path, or a parasitic resonance in one of the dots). In both datasets, the open symbols correspond to the peak height extracted from the fits at large E1, when the peak becomes visible again. The full symbols correspond to the value f(E1) of the measured distribution function taken at the injection energy. An important assumption here is that the peak position has not changed relative to the injection energy during propagation, which is validated for both L by the Lorentzian fits. Again, our results are well reproduced by the model including dissipation (thick dark blue and dark red lines), particularly the observed revival, with parameters displayed in Table 1. Interestingly, because the exponentially decaying prefactor arising from the additional friction term in our model directly depends on the velocity of the charge mode vρ, we are able to extract all relevant parameters of the TLL model in our experiment. In contrast, the TLL analysis performed on most previous experiments11,18,19,21,27,35 only provided the value of the dipole mode’s velocity vσ, while implying a strong coupling regime so that vρvσ. Using a rather simple refinement of the TLL model, we are thus able to show that, in our experiment, (i) the Fermi velocities in the two ECs differ typically by a factor 2, (ii) the effective EC coupling is moderate, and that (iii) as a consequence, the difference between the charge and dipole plasmon velocities is not as large as usually assumed. Note that ref. 39 demonstrated that those velocities depend on the voltage applied to the gate defining the channel, reporting similar values (up to a factor 2) in our range of gate voltage. We also show that while the friction parameter is highly sample dependent, it does not depend on the QD resonances within a given sample, or on thermal cycling.
### Effect of the length gate
Our analysis shows that the two devices differ not only by their nominal length and external dissipation but also by their plasmon velocities. Indeed, the 750 nm device presents a larger difference between vρ and vσ, effectively increasing the energy relaxation (or, in other words, making it effectively much longer than the 480 nm device as far as energy relaxation due to EC coupling is concerned). To interpolate between those two different cases, we rely on the length gate, the basic effect of which is illustrated in Fig. 5. For positive VL ≈ 0.2 V, the gate does not affect the trajectory of the ECs, which flow straight from QD1 to QD2 (Fig. 5a). The corresponding f(E) measured for L = 750 nm are shown in Fig. 5d, and are similar to the data shown in Fig. 2. For intermediate values VL ≈ −0.1 V, the electrostatic potential generated by the gate allows separating the two ECs40, as depicted in Fig. 5b: spectacularly, in that case all data show a very clear quasiparticle peak up to large E1 (Fig. 5e). In contrast, for large negative values VL ≈ −0.5 V, both ECs are diverted around the gate and follow a longer path (L = 2.17 μm, Fig. 5c), leading to the full disappearance of the quasiparticle peak even at low E1 (Fig. 5f, see also Fig. 6). The quasiparticle peak evolution in the data shown in Fig. 5d, e can be reproduced using our model (see Supplementary Note 5), with slightly different Fermi velocities for the two datasets (but the same velocity ratio α = 2.1). Interestingly, while the friction coefficient γ0 = 0.13 is the same for the two datasets (as well as for the other measurements in the L = 750 nm device), the extracted EC coupling u ≈ {83, 21} km s−1 is four times smaller when the two channels are separated. The length gate on the 480 nm device makes it possible to manipulate the ECs in the same way (Fig. 5g–i), allowing us to separate the ECs (Fig. 5h), as well as to increase the co-propagation length to L ≈ 1.3 μm (Fig. 5i). For the latter length, the quasiparticle peak decreases sharply, but remains visible up to 100 μeV. The TLL analysis of both datasets shows that, as for the 750 nm device, the friction coefficient remains constant, γ0 = 0.43 (see Supplementary Note 5 for additional plots and TLL analysis). For smaller gate voltages that do not fully separate the ECs, the length gate, coupled to the central gate separating the two QDs (see Fig. 1a), can nevertheless modify the electrostatic potential that defines the ECs flowing between the two dots, thereby granting us an additional control over the TLL parameters. We have performed the spectroscopy and TLL analysis of the quasiparticle peak height on the 480 and 750 nm devices for various gating configurations (see Supplementary Note 5 for plots and analysis, as well as a table summarizing the extracted TLL parameters). We observe consistently that the gate configuration allows tuning the plasmon velocities vρ and vσ, while the friction coefficient γ0 remains constant in each device.
### Prethermalization
We finally turn to the evolution of the measured distribution functions for propagation lengths above 1 μm. The integrability of the TLL model (in the absence of external dissipation) implies that energy relaxation should not lead to an equilibrium Fermionic state described by a high-temperature Fermi function25,41. This property has been recently confirmed by the observation of prethermalized states after the relaxation of highly imbalanced double-step distribution functions created by a biased quantum point contact27, but, up to now, not for finite energy quasiparticles. We have observed that as the propagation length is further increased, the quasiparticle peak fully vanishes. Notably, when the peak is no longer visible, the distribution function does not qualitatively change, up to our longest studied length, L = 3.4 μm. This is illustrated in Fig. 6 (see also Fig. 5f), where we have plotted the measured f(E) corresponding to the same injection energy E1 ≈ 63 μeV. Apart from the data at L = 480 nm, which display a clear quasiparticle peak, all other lengths yield similar, monotonous f(E). These distribution functions cannot be fully fitted by a Fermi function: the dashed and dotted lines in Fig. 6 are tentative fits of the (respectively) low- and high-energy part of the distribution functions, with significantly different effective temperature for the high-energy part (~160–195 mK) with respect to the low-energy part (~40–55 mK—see also Supplementary Note 6). Both fits show significant deviations with respect to the data. As a sanity check, we have measured equilibrium distribution functions at elevated temperatures (T ≈ 160 mK), corresponding to energy width similar to the data shown in Fig. 6, which showed much smaller deviations to a Fermi function (see Supplementary Note 6). Despite the significant role of energy losses towards external degrees of freedom, which should lead to a thermalized state after long propagation length, this apparent long-lived nonthermal behavior could indeed be a signature of TLL prethermalization. Furthermore, this might explain the recently reported robust quantum coherence of finite energy quasiparticles emitted in a Mach–Zehnder interferometer21. The apparent competition between prethermalization and observed dissipation is highly intriguing, and beckons further theoretical investigation of the impact of dissipation in the TLL model.
## Discussion
To summarize, we have directly observed the relaxation and revival of quasiparticles emitted at finite energy in an EC at filling factor ν = 2 of the quantum Hall effect. These results qualitatively reproduces the hallmark phenomenology of the TLL model, and we show that the quantitative discrepancies are well accounted for by introducing dissipation in the model. In order to maximize the phase coherence and energy relaxation lengths in electron quantum optics experiments, one should not only rely on schemes that limit the effect of inter-EC coupling26,42,43,44 but also identify the mechanisms behind this dissipation. A possible cause of this dissipation could be the recently observed long-distance Auger-like processes22, although their signature is again not visible in our data. This stresses the need for further research in order to fully grasp the physics of interactions at ν = 245.
## Methods
### Samples
The samples were realized in a 90 nm-deep GaAs/GaAlAs two-dimension electron gas, with typical density ~2.5 × 1011 cm−2 and mobility ~2 × 106 cm2 V−1 s−1, cooled down to electronic temperatures of ~20−30 mK. Perpendicular magnetic fields of about 5 T were applied to reach filling factor ν = 2 of the quantum Hall effect.
### Measurements
Measurements were performed in a dilution refrigerator, using standard low-frequency lock-in techniques. For each configuration of the experiment, the drain and source voltages VD and VS are tuned such that only a single narrow resonance sits in the transport window, with no excited states present. The spectroscopy range is then set by the minimum of {eVD, eVS}.
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2022-09-25 15:20:09
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http://tex.stackexchange.com/tags/input/hot
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# Tag Info
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\input{filename} imports the commands from filename into the target file; it's equivalent to typing all the commands from filename right into the current file where the \input line is \include{filename} essentially does a \clearpage before and after \input{filename}, together with some magic to switch to another .aux file, and omit the inclusion at all if ...
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Short answer: \input is a more lower level macro which simply inputs the content of the given file like it was copy&pasted there manually. \include handles the file content as a logical unit of its own (like e.g. a chapter) and enables you to only include specific files using \includeonly{filename,filename2,...} to save times. Long answer: The ...
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\input effectively replaces the command with the contents of the input file. \input's can be nested. So, you can write: \documentclass{article} \begin{document} AAA \input{b} AAA \end{document} where b.tex is: BBB \input{c} BBB and c.tex is: CCC to get output like: AAA BBB CCC BBB AAA include triggers a newpage both before and after the ...
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Edit: There is now LaTeX package for testing https://github.com/michal-h21/odsfile Before I post it on CTAN, any comments on style/grammar/spell in the documentation files, as well comments on the source code, are highly welcome. There is solution using luatex's zip library and pure lua xml processing library LuaXML, which you should install to same ...
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Manuel has posted an answer that uses line numbers; there's a recent package on CTAN that lets you do it with tags in the input file: catchfilebetweentags. An example is \usepackage{catchfilebetweentags} ... \ExecuteMetaData[file.tex]{tag} where the contents of the external file is surrounded by the "tags": %<*tag> ... %</tag>
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You can use the following tools to do this. All of them are on CTAN but are not part of either TeXLive nor MikTeX, so you need to manually install them. They need either Perl or a C compiler installed. Both should not be a problem with Linux but might be one under Windows or Mac. However IIRC TeXLive installs its own Perl interpreter. latexpand Perl ...
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I'm fuzzy on the details, but the import package should do what you want. Off the top of my head, I think the syntax is \usepackage{import} ... \subimport{code/doc/latex/}{refman.tex} Update: Thanks Willie for pointing out \subimport which seems to be the better command to use here over \import. The commands \import{full_path}{file} and ...
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From the LaTeX Wikibook : When working on big documents, you might want to split the input file into several parts. LaTeX has three commands to insert a file into another when building the document. The simplest is the \input command: \input{filename} \input inserts the contents of another file, named filename.tex; note that the ...
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Advantages It is a good trick, if someone wants to put TeX code before. Examples: pdflatex '\def\foo{bar}\input{filename}' pdflatex '\includeonly{introduction}\input{filename}' or inside \write18 (shell escape feature): \immediate\write18{\detokenize{pdflatex '\def\foo{bar}\input{filename}'}} \immediate\write18{\detokenize{pdflatex ...
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Your text ---------------> TeX --------------> PDF input encoding font encoding You need an input encoding to tell TeX how to interpret the contents of your text file, you need an font encoding for proper hyphenation. Old TeX can only hyphenate words from one font and therefore you need to squeeze all the characters you use ...
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You could split every report into two files: a main file holding only the preamble and an \input as document body, and a second file holding all the actual content. Then you are able to \input or \include all the content files in another main file for the book. % Main file of one report, e.g. report01.tex \documentclass{report} \title{...} ...
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Here's a case where \endinput might be useful. Suppose I'm writing a textbook and that each chapter ends with problems followed by their solutions. I want to build two separate editions: one for students, without solutions, one for teachers, with solutions. I can define a conditional, say \ifstudent, and prepare my chapters as <text> ...
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The check if a file exists is not expandable, because the file is opened using \openin\somefilehandle=<filename> which makes an assignment to \somefilehandle. Then \ifeof\somefilehandle is used to check if the end-of-file (EOF) is already reached, which is immediately true for non-existing files. Empty files, I think, need to be read at least once ...
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The snapshot package gives you a list of the external dependencies of a LaTeX document. Use it by saying \RequirePackage{snapshot} before the \documentclass command (to have the information written to a .dep file), or by saying \RequirePackage[log]{snapshot} before the \documentclass command (to have the information written to the .log file).
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Here's how it goes in texlive (and presumably other web2c distros): The changefile tex.ch removes the Knuth definition of input_ln; The underscore gets lost in the conversion of web to c; The resulting C code #includes texmfmp.h which does #define inputln(stream, flag) input_line (stream) The function input_line() gets defined in texmfmp.c where the ...
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I replaced your if-if-if-if construct with a simple \ifcase test. \moon works just fine now. Though the actual problem was another one. The counter assignments \global\advance\<counter> by 1 should be finished with a \relax. This also applies to the \ifnum but in this instance, it is not needed as math-mode is introduces right away. Without the \relax ...
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In my answer on greek text I gave an explanation which I'll basically repeat and extend here. I'll be basically talking about text encoding here, as it is rather obvious that math requires special treatment. Please also look at encguide where all this is explained in more detail. First of all, all this refers to TeX engines like pdftex which only support ...
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You can read the content of a file into a macro with Heiko Oberdiek's catchfile package: \CatchFileDef{\sometext}{somefile.txt}{<setup>} This will read the file like a normal TeX file, i.e. it can include macros etc. The <setup> argument can be empty for files read normally but can include special code to e.g. read the file content verbatim or ...
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In TeX Live, the formats for pdf(la)tex and lua(la)tex are built loading the tcx translation file cp227.tcx that makes ^^I "printable". This means that a category code 12 ^^I is written out as a real tab character. On the other hand, xetex ignores tcx translation requests and behaves, in this respect, like Knuth's TeX (but it writes UTF-8, of course). A ...
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No, you don't need it. \endinput is used for terminating the input process in the middle of a file. A \endinput at the end of a file is useless (and harmless). Some ones like to use \endinput to show the end of file explicitly. IMHO, it make no sence.
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Normally this is done using the listings package. It provides a lstlisting environment for verbatim code and also a \lstinputlisting[<options,...>]{<file name>} to include an external file verbatim. As options you can select language=C++ to get specific syntax highlighting. I also usually use basicstyle=\ttfamily. See the listings package manual ...
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The LaTeX \input command, by Lamport's choice, must support both \input{file} and \input file so it's necessary to define it in that way: a test on the following character is necessary as the primitive \input scans its argument in a very peculiar way. If you don't want to support the original syntax inside your environment, then putting ...
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I did not understand where do you want to put the text: in the main file jobname.aux or in the separate file. If the former, this works (basically modelled after the standard \ref-\label mechanism): \documentclass{article} \makeatletter % The command reference writes \newreference into the aux file \def\createreference#1#2{\@bsphack ...
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\input is trying to be intelligent, and this seems to be upsetting LaTeX's picky tabular definition. But you can access the original \input primitive from TeX which is less dangerous at this point. After defining \makeatletter \newcommand\primitiveinput[1] {\@@input #1 } \makeatother using \primitiveinput inside the tabular should work.
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It's easy to see where the loop comes from as \Bigr is defined in terms of \Big which is (by default) \def\Big#1{{\hbox{$\left#1\vbox to11.5\p@{}\right.\n@space$}}} so defined in terms of \left It is probably safer just to do a replace/edit on the incoming file If you wanted to do this in TeX you'd neeed \let\oldleft\left \let\oldright\right and ...
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Without a \read: \documentclass{article} \usepackage{catchfile} \newcommand{\setcounterfromfile}[2]{% #1 = counter, #2 = file name \CatchFileDef{\scfftemp}{#2}{\endlinechar=-1 }% \setcounter{#1}{\scfftemp}} \newcounter{cnt} \setcounterfromfile{cnt}{numberfile} \showthe\value{cnt} If numberfile.tex contains the only line 12345 (a very difficult ...
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Here is an approach in pure TeX (well, e-TeX). The main idea is: to select a range of lines in a file, sed is overkill, TeX is more than enough. As a bonus, no temporary file is needed. \documentclass[a4paper]{article} \usepackage[ascii]{inputenc} \usepackage[T1]{fontenc} \usepackage{lmodern} \makeatletter \newread\pin@file \newcounter{pinlineno} ...
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TestInput.out probably contains a new line at the end of the file (text files usually do, even when created with echo 'abc' > file). TeX interprets new lines as spaces. To remove that space, simply add \unskip directly afterwards, i.e. use A\input{TestInput.out}\unskip B (this will also remove any intentional space at the end of the file, should there ...
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There is as far as I know no way to get around the problem. How TeX handles files with unusual numbers of dots (where "unusual" is any number unequal to 1) is quite inpredictable and also has changed over time. In miktex 2.4 e.g. \input{file.cfg} would have tried at first file.cfg then file.cfg.tex, in miktex 2.5 it tried only file.cfg, in the current 2.9 ...
Only top voted, non community-wiki answers of a minimum length are eligible
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2013-05-22 12:07:46
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https://www.thejournal.club/c/paper/54892/
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Counting Triangulations and other Crossing-Free Structures Approximately
Victor Alvarez, Karl Bringmann, Saurabh Ray, Raimund Seidel
We consider the problem of counting straight-edge triangulations of a given set $P$ of $n$ points in the plane. Until very recently it was not known whether the exact number of triangulations of $P$ can be computed asymptotically faster than by enumerating all triangulations. We now know that the number of triangulations of $P$ can be computed in $O^{*}(2^{n})$ time, which is less than the lower bound of $\Omega(2.43^{n})$ on the number of triangulations of any point set. In this paper we address the question of whether one can approximately count triangulations in sub-exponential time. We present an algorithm with sub-exponential running time and sub-exponential approximation ratio, that is, denoting by $\Lambda$ the output of our algorithm, and by $c^{n}$ the exact number of triangulations of $P$, for some positive constant $c$, we prove that $c^{n}\leq\Lambda\leq c^{n}\cdot 2^{o(n)}$. This is the first algorithm that in sub-exponential time computes a $(1+o(1))$-approximation of the base of the number of triangulations, more precisely, $c\leq\Lambda^{\frac{1}{n}}\leq(1 + o(1))c$. Our algorithm can be adapted to approximately count other crossing-free structures on $P$, keeping the quality of approximation and running time intact. In this paper we show how to do this for matchings and spanning trees.
arrow_drop_up
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2022-08-11 02:37:38
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http://xrpp.iucr.org/Bb/ch1o3v0001/sec1o3o2o3o6/
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International
Tables for
Crystallography
Volume B
Reciprocal space
Edited by U. Shmueli
International Tables for Crystallography (2010). Vol. B, ch. 1.3, p. 30 | 1 | 2 |
## Section 1.3.2.3.6. Distributions associated to locally integrable functions
G. Bricognea
aGlobal Phasing Ltd, Sheraton House, Suites 14–16, Castle Park, Cambridge CB3 0AX, England, and LURE, Bâtiment 209D, Université Paris-Sud, 91405 Orsay, France
#### 1.3.2.3.6. Distributions associated to locally integrable functions
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Let f be a complex-valued function over Ω such that exists for any given compact K in Ω; f is then called locally integrable.
The linear mapping from to defined bymay then be shown to be continuous over . It thus defines a distribution :As the continuity of only requires that , is actually a Radon measure.
It can be shown that two locally integrable functions f and g define the same distribution, i.e.if and only if they are equal almost everywhere. The classes of locally integrable functions modulo this equivalence form a vector space denoted ; each element of may therefore be identified with the distribution defined by any one of its representatives f.
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2019-05-21 11:46:37
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http://docs.xtxt.sygnal.com/markup/definitionlist/
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# Usage (Condensed)
/def
Term
Definition (line 1)
Definition (line 2)
...
Definition (line n)
# Usage (Full)
/def
.
/dt
Term
.
/dd
Definition (line 1)
Definition (line 2)
...
Definition (line n)
.
\def
Synonyms: definitionlist , deflist , dl
xTxT supports the specification of definition lists, modeled after HTML.
A definition list is a collection of terms and definitions, in such a way that you can group together terms and definitions any way you like. This means that you have one term and one definition, or two terms and one definition, one term and two definitions, 5 terms and 8 definitions, and so on.
There are many ways that you can use definition lists, such as to represent dialogue with the term containing the speaker's name, and the definition containing the speech.
## Attributes
style
(optional) An HTML style string to apply to the element.
## Markup
There are two approaches to marking up definition content.
### Simple
/def
Miru
The world's best WebCMS, ever.
### Compound
/def
/term
/definition
def
A definition begins with a definition list (/def)
## Def (/def)
/def
wIkI
A very cool tool for generating HTML.
Generates the following HTML;
<dl>
<dt>wIkI</dt>
<dd>A very cool tool for generating HTML.</dd>
</dl>
Which renders as;
wIkI
A very cool tool for generating HTML.
# 1.0 Notes
In 1.0, only the amalgamated structure is supported.
e.g.
/def
term
definition line 1
definition line 2
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2017-08-23 19:26:35
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https://artofproblemsolving.com/wiki/index.php/2012_USAJMO_Problems/Problem_2
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# 2012 USAMO Problems/Problem 1
## Problem
Find all integers $n \ge 3$ such that among any $n$ positive real numbers $a_1$, $a_2$, $\dots$, $a_n$ with $$\max(a_1, a_2, \dots, a_n) \le n \cdot \min(a_1, a_2, \dots, a_n),$$ there exist three that are the side lengths of an acute triangle.
## Solution
Without loss of generality, assume that the set $\{a\}$ is ordered from least to greatest so that the bounding condition becomes $a_n \le n \cdot a_1.$ Now set $b_i \equiv \frac{a_i}{a_1},$ and since a triangle with sidelengths from $\{a\}$ will be similar to the corresponding triangle from $\{b\},$ we simply have to show the existence of acute triangles in $\{b\}.$ Note that $b_1 = 1$ and for all $i$, $b_i \le n.$
Now three arbitrary sidelengths $x$, $y$, and $z$, with $x \le y \le z,$ will form a valid triangle if and only if $x+y>z.$ Furthermore, this triangle will be acute if and only if $x^2 + y^2 > z^2.$ However, the first inequality can actually be inferred from the second, since $x+y>z \longrightarrow x^2 + y^2 +2xy > z^2$ and $2xy$ is trivially greater than $0.$ So we just need to find all $n$ such that there is necessarily a triplet of $b$'s for which $b_i^2 + b_j^2 > b_k^2$ (where $b_i < b_j < b_k$).
We now make another substitution: $c_i \equiv b_i ^2.$ So $c_1 = 1$ and for all $i$, $c_i \le n^2.$ Now we examine the smallest possible sets $\{c\}$ for small $n$ for which the conditions of the problem are not met. Note that by smallest, we mean the set whose greatest element is as small as possible. If $n=3$, then the smallest possible set, call it $\{s_3\},$ is trivially $\{1,1,2\}$, since $c_1$ and $c_2$ are obviously minimized and $c_3$ follows as minimal. Using this as the base case, we see inductively that in general $\{s_n\}$ is the set of the first $n$ Fibonacci numbers. To show this note that if $\{s_n\} = \{F_0, F_1, ... F_n\}$, then $\{s_{n+1}\} = \{F_0, F_1, ... F_n, c_{n+1}\}.$ The smallest possible value for $c_{n+1}$ is the sum of the two greatest values of $\{s_n\}$ which are $F_{n-1}$ and $F_n$. But these sum to $F_{n+1}$ so $\{s_{n+1}\} = \{F_0, F_1, ... F_{n+1}\}$ and our induction is complete.
Now since we know that the Fibonacci set is the smallest possible set which does not satisfy the conditions of the problem, then any set $\{c\}$ whose greatest term is less than $F_{n-1}$ must satisfy the conditions. And since $\{c\}$ is bounded between $1$ and $n^2$, then the conditions of the problem are met if and only if $F_{n-1} > n^2$. The first $n$ for which this restriction is satisfied is $n=13$ and the exponential behavior of the Fibonacci numbers ensure that every $n$ greater than $13$ will also satisfy this restriction. So the final solution set is $\boxed{\{n \ge 13\}}$.
## Solution 2
Outline:
1. Define the Fibonacci numbers to be $F_1 = F_2 = 1$ and $F_k = F_{k-1} + F_{k-2}$ for $k \ge 3$.
2. If the chosen $n$ is such that $F_n \le n^2$, then choose the sequence $a_n$ such that $a_k = \sqrt{F_k}$ for $1 \le k \le n$. It is easy to verify that such a sequence satisfies the condition that the largest term is less than or equal to $n$ times the smallest term. Also, because for any three terms $x = \sqrt{F_a}, y = \sqrt{F_b}, z = \sqrt{F_c}$ with $a, $x^2 + y^2 = F_a + F_b \le F_{b-1} + F_b = F_{b+1} \le F_c = z^2$, x, y, z do not form an acute triangle. Thus, all $n$ such that $F_n \le n^2$ do not work.
3. It is easy to observe via a contradiction argument that all $n$ such that $F_n > n^2$ produce an acute triangle. (If, without loss of generality, $a_n$ is an increasing sequence, such that no three (in particular, consecutive) terms form an acute triangle, then $a_2^2 \ge F_1a_1^2, a_3^2 \ge a_2^2 + a_1^2 \ge F_2a^2$, and by induction $a_n^2 > F_na_1^2$, a contradiction to the condition's inequality.)
4. Note that $F_{12} = 144 = 12^2$ and $F_{13} = 233 > 169 = 13^2$. It is easily to verify through strong induction that all $n$ greater than 12 make $F_n > n^2$. Thus, $\boxed{n \ge 13}$ is the desired solution set.
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2021-04-21 16:15:18
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https://www.cheenta.com/multiplication-principle-isi-mstat-year-2019-psa-problem-11/
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Get inspired by the success stories of our students in IIT JAM 2021. Learn More
# How to Pursue Mathematics after High School?
For Students who are passionate for Mathematics and want to pursue it for higher studies in India and abroad.
This is a beautiful problem from ISI MSTAT 2019 PSA problem 11 based on multiplication principles. We provide sequential hints so that you can try.
## Multiplication Principle - ISI MStat 2019 PSA - 11
How many positive divisors of $2^55^3{11}^4$ are perfect squares?
• 60
• 18
• 120
• 4
### Key Concepts
Basic counting principles
Divisors of a number
ISI MStat 2019 PSA Problem 11
A First Course in Probability by Sheldon Ross
## Try with Hints
See in order to get the positive divisors of $2^55^3{11}^4$ that are perfect squares , we need to take only the even powers of the primes {2,5,11}.
Now the maximum powers of 2 is 5 . So there are 3 choices for even powers {0,2,4} .
The maximum powers of 5 is 3 . So there are 2 choices for even powers {0,2}.
Now the maximum powers of 2 is 5 . So there are 3 choices for even powers {0,2,4} .
The maximum powers of 11 is 4 . So there are 3 choices for even powers {0,2,4}.
Hence by multiplication principle we have in total $3 \times 2 \times 3 =18$ such positive divisors.
## What to do to shape your Career in Mathematics after 12th?
From the video below, let's learn from Dr. Ashani Dasgupta (a Ph.D. in Mathematics from the University of Milwaukee-Wisconsin and Founder-Faculty of Cheenta) how you can shape your career in Mathematics and pursue it after 12th in India and Abroad. These are some of the key questions that we are discussing here:
• What are some of the best colleges for Mathematics that you can aim to apply for after high school?
• How can you strategically opt for less known colleges and prepare yourself for the best universities in India or Abroad for your Masters or Ph.D. Programs?
• What are the best universities for MS, MMath, and Ph.D. Programs in India?
• What topics in Mathematics are really needed to crack some great Masters or Ph.D. level entrances?
• How can you pursue a Ph.D. in Mathematics outside India?
• What are the 5 ways Cheenta can help you to pursue Higher Mathematics in India and abroad?
## Want to Explore Advanced Mathematics at Cheenta?
Cheenta has taken an initiative of helping College and High School Passout Students with its "Open Seminars" and "Open for all Math Camps". These events are extremely useful for students who are really passionate for Mathematic and want to pursue their career in it.
To Explore and Experience Advanced Mathematics at Cheenta
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2021-08-05 23:36:41
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https://www.physicsforums.com/threads/divide-a-number-by-0.157251/
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# Divide a number by 0
1. Feb 20, 2007
### JPC
Hey just wondering
if u divide any real number by 0 is it + infinite or - infinite
is it : +infinite when the number if positive, and -infinite when the number is negative ?
2. Feb 20, 2007
### benorin
Technically, division by zero is undefined; but, essentially yes, with a few modifications: dividing a positive real number by a number which approaches zero through positive values approaches $$+\infty$$. Consider the graph of $$y=\frac{3}{x}$$ below:
note that the function value (or y value) approaches $$+\infty$$ as x approaches zero through positive values (from the right side of zero); but the function value (or y value) approaches $$-\infty$$ as x approaches zero through negative values (from the left side of zero).
#### Attached Files:
• ###### 3overX.jpg
File size:
45.4 KB
Views:
110
Last edited: Feb 20, 2007
3. Feb 23, 2007
### JPC
yeah but i mean , is 0 positive or negative ?
or is it just undefined as u said ?
4. Feb 23, 2007
### dextercioby
0 is neither positive, nor negative and division by 0 in arithmetics over reals is undefined.
5. Feb 23, 2007
### DaveC426913
Dividing by zero does not result in infinity, it results in undefined. Here's why:
The division operation, by definition, is the inverse of multiplication. 6/3 is equal to 2 because 2*3=6.
But if we try that with zero, we start with 0*x=6. This equation has no solution at all - there is no value of x (including infinity) that can make that equation true.
Since the multiplicative has no solution, the inverse has no solution (not even infinity).
Last edited: Feb 23, 2007
6. Feb 23, 2007
### haiha
Dividing by zero is undefined. In fact when someone says a number A (positive) divided by zero, he means it is divided by an epsilon and then find the lim of the result when epsilon approaches to zero. So depending the sign of epsilon, the result can be + infinitive or - infinitive. I mean epsilon can approache zero origine either from the left or from the right then we have -0 or +0.
7. Feb 23, 2007
### arildno
Does he mean that? I don't think so..
SHOULD he mean that? He certainly should not.
8. Feb 23, 2007
### Werg22
I don't understand why some people are obstinate about undefined operations. Mathematics is not nature made, it's man made, and man dictates its functioning. How we define our numbers and their arithmetic makes the expression x / 0 irrelevant. It does not mean anything.
9. Feb 24, 2007
### leon1127
INFINITY IS NOT A NUMBER! Thus we cannot define dividion with zero. To prove that infinity is not a number
let suppose
inf = 1/0;
then 0* inf = 1,
but 0 = 1 * 0 = 0 * (0 * inf ) = (0 * 0 ) * inf = inf * 0 = 1
Thus division with zero is still remain undefined.
Last edited: Feb 24, 2007
10. Feb 25, 2007
### robert Ihnot
dextercioby: 0 is neither positive, nor negative and division by 0 in arithmetics over reals is undefined.
The standard proceedure with historians is to go from 1BC to 1AD, thus 1000AD is 999 years after 1 BC. If you consider BC to be negative and AD to be positive, well then, as you see here, there is no such thing as year 0, so it can not be positive or negative in this system.
Last edited: Feb 25, 2007
11. Feb 25, 2007
### Hurkyl
Staff Emeritus
What does that have to do with anything?
12. Feb 25, 2007
### robert Ihnot
Hurkyl: What does that have to do with anything?
i am sorry if this is troublesome, i thought it was a joke. I could have added, it does illustrate the fact that 0 was not accepted by early historians, and so the tradition just continued. It is the reason why we are now in the 21st Century, but in the year 2007.
Last edited: Feb 25, 2007
13. Feb 25, 2007
### HallsofIvy
Yes- it does not mean anything because it is not defined to be anything- it is undefined. When you refer to people being "obstinate" about undefined operations, exactly what do you mean?
14. Feb 25, 2007
### DaveC426913
But simply declaring that "it is undefined because we say so" is not a satisfactory answer.
There IS a good, logical reason why it is undefined, and it can be shown, as posts 5 and 9.
15. Feb 25, 2007
### Hurkyl
Staff Emeritus
There are two separate issues here.
"It is (un)defined because we say so" is essentially the only correct answer to the question "Is it defined?" There is no higher reason for it -- either an expression syntactically satisfies the requirements of a definition, or it does not.
1/0 is undefined (for real division) precisely because this expression fails to satisfy the requirement that the dividend is a real number and the divisor is a nonzero real number. Similarly, if x is a variable denoting a real number, then x/x is undefined. (y/y would be defined if y is a variable denoting a nonzero real number, though)
You are talking about the reason why we would ever have chosen to define division this way. There is a good reason for that. (I think "practical" is more accurate than "logical", though) But the reasons for choosing the definition are entirely irrelevant to the question of what is or is not defined.
16. Feb 25, 2007
### DaveC426913
Why would you insist that we defined it a certain way before there was a reason to need it to be that way? Isn't that putting the cart before the horse? Or a fabulously lucky premonition?
Surely, the historical order of occurence is:
1] We "invent" division (as the inverse of multiplcation)
2] We realize that dividing by zero is problematic
3] We put in place a rule so as not to cause problems
17. Feb 25, 2007
### Hurkyl
Staff Emeritus
I'm not. There is a difference between the question
"Why is 1/0 undefined?"
and the question
"Why did we define division so that 1/0 is undefined?"
18. Feb 25, 2007
### minase
If we say y(a number) divided by x as x approched infity equals 0. Can we say 0 times x as x approches infity equals Y.
Does division by 0 is undefined for only real numbers or all complex numbers.
Last edited: Feb 25, 2007
19. Feb 25, 2007
### Hurkyl
Staff Emeritus
This doesn't make sense. I will assume you meant to say:
"The limit of y divided by x, as x approaches infinity, equals 0"
or equivalently
"y divided by x approaches 0 as x approaches infinity"
Similarly, I will assume you meant to say
"The limit of 0 times x, as x approaches infinity, equals y"
or equivalently
"0 times x approaches y as x approaches infinity"
The second statement does not follow (directly or indirectly) from the first. The second statement is true iff y = 0.
20. Feb 25, 2007
### minase
Can you use the same rule for limits as an ordinary equation y/x=0, 0*x=Y.
21. Feb 26, 2007
### HallsofIvy
"If we say y(a number) divided by x as x approched infity equals 0. Can we say 0 times x as x approches infity equals Y."
"limit of y/x, as x goes to infinity, y fixed, equals 0" is only true if y is not 0.
No, we cannot say "0*x, as x approaches infinity equals y". 0*x for any real x is 0 so the limit is 0.
22. Feb 26, 2007
### minase
When we did integration isn't it the same thing what we were doing when adding up all the rectangles. The sum of all the rectangles as dx approches 0. Sorry i am a bit confused. Math is not my strongest subject.
23. Feb 26, 2007
### HallsofIvy
No, it's not at all the same thing.
24. Feb 28, 2007
### ZioX
Last edited: Feb 28, 2007
25. Feb 28, 2007
### HallsofIvy
No, we don't know that because it isn't true. "infinity" is not a number so 1/0= infinity is non-sense. The golden ratio is a number but neither 00 nor 0/0 is so that last statement is false.
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2018-05-27 05:37:52
|
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https://zbmath.org/?q=an:1328.05207
|
Partial coloring, vertex decomposability and sequentially Cohen-Macaulay simplicial complexes.(English)Zbl 1328.05207
Summary: In attempting to understand how combinatorial modifications alter algebraic properties of monomial ideals, several authors have investigated the process of adding “whiskers” to graphs. In this paper, we study a similar construction for building a simplicial complex $$\Delta_\chi$$ from a coloring $$\chi$$ of a subset of the vertices of $$\Delta$$ and give necessary and sufficient conditions for this construction to produce vertex decomposable simplicial complexes. We apply this work to strengthen and give new proofs about sequentially Cohen-Macaulay edge ideals of graphs.
MSC:
05E45 Combinatorial aspects of simplicial complexes 05A15 Exact enumeration problems, generating functions 13C14 Cohen-Macaulay modules 13F55 Commutative rings defined by monomial ideals; Stanley-Reisner face rings; simplicial complexes
Full Text:
References:
[1] J. Biermann and A. Van Tuyl, Balanced vertex decomposable simplicial complexes and their $$h$$-vectors . Electr. J. Comb. 20 (2013) #P15. · Zbl 1298.05332 [2] A. Björner, P. Frankl and R. Stanley, The number of faces of balanced Cohen-Macaulay complexes and a generalized Macaulay theorem , Combinatorica 7 (1987), 23-34. · Zbl 0651.05010 [3] A. Björner and M. Wachs, Shellable nonpure complexes and posets I, Trans. Amer. Math. Soc. 348 (1996), 1299-1327. · Zbl 0857.05102 [4] CoCoATeam, CoCoA: A system for doing computations in commutative algebra , available at http://cocoa.dima.unige.it. [5] D. Cook, II, Simplicial decomposability , JSAG 2 (2010), 20-23. · Zbl 1311.05002 [6] D. Cook, II and U. Nagel, Cohen-Macaulay graphs and face vectors of flag complexes , SIAM J. Discr. Math. 26 (2012), 89-101. · Zbl 1245.05138 [7] A. Dochtermann and A. Engström, Algebraic properties of edge ideals via combinatorial topology , Electr. J. Combin. 16 (2009), Research Paper 2, 24 pages. · Zbl 1161.13013 [8] C. Francisco and H.T. Hà, Whiskers and sequentially Cohen-Macaulay graphs , J. Comb. Theor. 115 (2008), 304-316. · Zbl 1142.13021 [9] A. Frohmader, How to construct a flag complex with a given face vector , preprint (2011 arXiv: [10] D.R. Grayson and M.E. Stillman, Macaulay2, A software system for research in algebraic geometry , http://www.math.uiuc.edu/Macaulay2/. [11] J. Herzog and T. Hibi, Monomial ideals , Grad. Texts Math. 260 , Springer-Verlag, New York, 2011. · Zbl 1206.13001 [12] J. Jonsson, Simplicial complexes of graphs , Lect. Notes Math. 1928 , Springer-Verlag, Berlin, 2008. · Zbl 1152.05001 [13] J. Provan and L. Billera, Decompositions of simplicial complexes related to the diameters of convex polyhedra , Math. Oper. Res. 5 (1980), 576–594. · Zbl 0457.52005 [14] A. Van Tuyl, Sequentially Cohen-Macaulay bipartite graphs : Vertex decomposability and regularity , Arch. Math. 93 (2009), 451-459. · Zbl 1184.13062 [15] R.H. Villarreal, Cohen-Macaulay graphs , Manuscr. Math. 66 (1990), 277–293. · Zbl 0737.13003 [16] R. Woodroofe, Vertex decomposable graphs and obstructions to shellability , Proc. Amer. Math. Soc. 137 (2009), 3235-3246. · Zbl 1180.13031 [17] —-, Chordal and sequentially Cohen-Macaulay clutters , Electr. J. Comb. 18 (2011), Paper 208, 20 pages. · Zbl 1236.05213
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.
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2022-07-03 02:22:34
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https://zbmath.org/?q=an:0734.46012
|
## Primariness of some spaces of continuous functions.(English)Zbl 0734.46012
Summary: J. Roberts and the author have recently shown that, under the continuum hypothesis, the Banach space $$\ell_{\infty}/c_ 0$$ is primary. Since this space is isometrically isomorphic to the space $$C(\omega^*)$$ of continuous scalar functions on $$\omega^*=\beta \omega -\omega$$, it is quite natural to consider the question of primariness also for the spaces of continuous vector functions on $$\omega^*$$. The present paper contains some partial results in that direction. In particular, from our results it follows that $$C(\omega^*,C(K))$$ is primary for any infinite metrizable compact space K (without assuming the CH).
### MSC:
46B25 Classical Banach spaces in the general theory 46B45 Banach sequence spaces 46E40 Spaces of vector- and operator-valued functions 46E15 Banach spaces of continuous, differentiable or analytic functions 03E50 Continuum hypothesis and Martin’s axiom
Full Text:
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2022-05-29 08:37:01
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https://earthscience.stackexchange.com/tags/sea-level/hot?filter=year
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# Tag Info
26
Sea level has a strong seasonal signal. The annual variability is less than the daily changes associated with tidal forcing in most locations, but still can be on the order of 5-10 cm (maximum values about 15 cm). The causes of the seasonal fluctuations are mostly associated with seasonal changes in wind intensity and patterns, changes in temperature that ...
20
Earth's radius is about 6400 kilometres. That's 6400000 metres. Let's say that you have a mound 20 metres high, burying an older settlement. Your new "radius" is now 6400020 metres. Let's say that $g = 9.8\ \rm m/s^2$ at 6400, your new gravity will be $g = 9.799939\ \rm m/s^2$. Clearly, this is hardly "lower level of gravity". To make this even less ...
6
Tectonic activity can change the volume of oceanic basins and hence, modify the sea level, ice not involved. Firstly let's explain the left picture. At Cretaceous the tectonic activity was high. The flux of material from mantle to ocean ridges and plateaux reduced the volume of ocean basins, wich produced a global high sea-level observed in differents ...
5
You could try building one using a global Digital Elevation Model. There are several freely available like TanDEM-X, SRTM, or ASTER GDEM. You'd have to look for all the pixels containing a negative value. Adjacent negative pixels would give you connected regions below sea level, and you could easily estimate their area just by multiplying the number of ...
5
A paper about this was published yesterday in Nature Climate Change: Sandy coastlines under threat of erosion (Vousdoukas et al. 2020). While shoreline change can be the combined result of a wide range of potentially erosive or accretive factors, there is a clear cause and effect relationship between increasing sea levels and shoreline retreat, pointing ...
5
As a prescript, your question is firmly within the field of Glacio-Isostatic Adjustment (GIA) modeling of the Earth and the sea level. The main scientific names doing research in this direction are Jerry Mitrovica, W.R. Peltier, Roblyn Kendall, Glenn Milne, Kurt Lambeck, Giorgio Spada, and probably some more that I'm forgetting. It all comes down to, ...
5
To address your original concern, no, the fact that there are buildings underground does NOT mean that the surface of the earth is higher than in the past. What is actually happening is that these buildings are subsiding into the ground. How? Believe it or not, earthworms. Worms were once constantly tunneling through the soil underneath ancient buildings, ...
2
In the Arctic there is mostly floating sea ice and the mass of this does not change the sea level. When snow falls on the floating sea ice the weight of the snow is the same as the weight of the sea water it displaces so there will not be any change in sea level from this. But the snow falling on land during winter is water temporary removed from the sea, ...
2
SLR is thought to be caused by temperature rise, which is caused by CO2 rise and other factors. Temperature has been rising since before 1850. It could be another Question: "Why temperature does not correspond with CO2 levels since 1850". The reconstructions used, in order from oldest to most recent publication are: (dark blue 1000-1991): The ...
2
The jaguar is a close relative of the Asiatic leopard and must have had a common ancestor within the last 5 million years. The South American tapir is obviously closely related to the Malayan tapir and must also have had a common ancestor within he last 5 million years. While the first statement is more or less correct, the latter is not. The Asian and ...
1
This is no an answer per se, just a back-of-the-envelope calculation for fun. Lifting 1 kg (one litre) of water up a height of 1 meter uses 9.8 (let's say 10) joules of energy. Let's say you want to lower the sea level by 1 meter. You need to pump 3.6e17 litres (3.6e14 m2 of ocean area = 3.6e14 m3 to pump * 1000 for litre conversion). Let's say you want ...
1
During glaciations, the shelves down to ~100m depth would have been above sea level, but they would have been covered by ice sheets. Geology.com The actual "ocean floor" would still be deep water. There is a general explanation of the oil formation here and here, although they don't say when (or where the continents were when the sediments were deposited), ...
1
Arkaia's answer gives good information on the primary cause, which is the multitude of different astronomical changes that operate on various different timescales. However, there's an additional consideration, which is "storm surge" or, more colloquially, "what the weather is doing". Differences in atmospheric pressure between different areas can lead to ...
Only top voted, non community-wiki answers of a minimum length are eligible
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2020-04-01 12:20:05
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https://pharmacyscope.com/blood-pressure/
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# Blood pressure
Blood pressure is defined as the lateral pressure exerted by the blood on the walls of the blood vessels. The BP is measured in terms of systolic/ diastolic and pulse pressure. The normal blood pressure maintains sufficient pressure to keep the blood flowing from the heart to the periphery and from the periphery to the heart. The BP is measured by a sphygmomanometer.
## Normal range of Blood pressure
SP= 110-145 mm/Hg
DP= 70-90mm/Hg
PP = 40-55mm/Hg
## Standard Blood pressure
SP= 120 mm/Hg
DP= 80 mm/Hg
PP = 40 mm/Hg
Systolic pressure: it represents the maximum pressure produced by the ventricles during contraction, generally it reflects cardiac output.
Diastolic pressure: It is the pressure during the relaxation of the heart and reflects peripheral resistance.
Pulse pressure: The difference between systolic and diastolic pressure is known as pulse pressure.
Blood pressure is determined by cardiac output and Peripheral resistance
Blood Pressure = Cardiac output × Peripheral resistance
If there is an increase in cardiac output and peripheral resistance then leads to an increase in BP and a condition is known as Hypertension.
Blood Pressure is controlled in 2 ways
1. Short term baroreceptor reflex
2. Long term Renin-angiotensin aldosterone mechanism
## Renin-angiotensin aldosterone mechanism
This is one of the most important systems regulating BP. When there is an increase in sympathetic stimulation the neutral endings release neurotransmitter noradrenaline from the nerve endings, this noradrenaline acts on blood vessels thereby causing vasoconstriction and thereby causing increased peripheral resistance
• Peripheral resistance causes a decrease in blood supply to kidneys, when there is a decrease in renal perfusion, kidneys release Renin (protein) secreted by the juxtaglomerular cells of the kidney.
• The renin thus released activated angiotensinogen (a globulin formed in the liver and found in plasma) to form angiotensin I, II, and III by the angiotensin-converting enzyme ( ACE )
• Angiotensin I and III do not have any significant action but angiotensin II is a potent vasoconstrictor agent it still causes the constriction of blood vessels and thereby causing an increase in peripheral resistance.
• Angiotensin II also acts on the adrenal cortex to release aldosterone, the aldosterone causes sodium reabsorption and thereby increases blood volume and cardiac output.
Make sure you also check our other amazing Article on: Peripheral Nervous System
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2023-02-03 04:07:38
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https://codereview.stackexchange.com/questions/14647/get-unique-entries-from-array
|
# Get unique entries from array
For a website I'm working on, I had to get all the unique entries in an array and count their occurrence. It is possible a certain entry is only found once, but it can also be found 20 times. So I designed the following bit of code:
for ($i = 0;$i < count($nodes);$i++)
{
for ($j = 0;$j < count($nodes[$i]); $j++) { if (!array_key_exists($nodes[$i][$j], $uniekenodes)) {$uniekenodes[$nodes[$i][$j]] = 1; } else {$uniekenodes[$nodes[$i][$j]] += 1; } } } The $nodes array contains the the entries returned from the database. And the $uniekenodes array contains the unique entries and how many times they occured in the $nodes array.
This is my first php script (on a drupal webpage by the way) and as such I don't know that much about php. I'm pretty confident there is probably a more a efficient way to do this, using php-specific functions. Any and all tips are welcome!
EDIT: I might have to clarify the structure of the arrays:
$nodes has two dimensions. The first dimension is just a key for the second dimension. This one contains an array of drupal nodes for each key. $uniekenodes uses the nodes from $nodes as a key and the value is how many times the node occured in $nodes
EDIT 2:
I printed the arrays, as requested by Boris Guéry:
Array
(
[0] => Array //Each of these contains node id's returned by a query
(
[0] => 12
[1] => 11
[2] => 10
[3] => 9
[4] => 8
[5] => 7
)
[1] => Array
(
[0] => 10
[1] => 9
[2] => 8
[3] => 7
)
[2] => Array
(
)
[3] => Array
(
[0] => 11
[1] => 10
[2] => 9
[3] => 8
[4] => 7
)
)
Array //This one uses the node ids from the previous array as keys, the values are the number of occurences.
(
[12] => 1
[11] => 2
[10] => 3
[9] => 3
[8] => 3
[7] => 3
)
• Post an example of your array structure – Boris Guéry Aug 14 '12 at 9:06
• @BorisGuéry Added an example. – Simon Verbeke Aug 14 '12 at 9:52
First off, foreach loops would make this look much nicer. Also, its always better to use the "not operator" ! only if you have to. For instance, in your situation you do something either way, so switch it around.
foreach( $nodes AS$node ) {
foreach( $node AS$value ) {
if( array_key_exists( $value,$uniekenodes ) ) {
$uniekenodes[$value ] += 1;
} else {//the not is now the else
$uniekenodes[$value ] = 1;
}
}
}
I had the initial idea that you could just use array_count_values() on each interior array then combine them. You can still do this, but combining them wasn't as easy as I thought it would be. Maybe I'm missing something... Anyways, I found another solution. It SHOULD work, but I've not tested it, so no promises. I'm not really sure how I feel about the closure, but it seems to be picking up common use. In the end, both the above method and this one below are fine, its up to you to decide which to use. I'm not even sure where I stand on this one. The bottom one is cleaner, but the top one I'm more familiar with. Its fun to play around with stuff like this and experiment. I'll have to see how this works out in some of my projects. Its always good when you walk away having learned something yourself. Thanks for giving me an excuse to play around with something new :)
array_walk_recursive( $nodes, function($value, $key ) use( &$uniekenodes ) {
if( array_key_exists( $value,$uniekenodes ) ) {
$uniekenodes[$value ] += 1;
} else {
$uniekenodes[$value ] = 0;
}
} );
On a final note, I would consider renaming the $uniekenodes array. It is just awkward and I wouldn't have known what was in it if you hadn't told me. $uniqueNodes is good, or $nodeFrequency, or anything else that better describes it. Unless, of course, this is in another language and that is a good description (I don't know, looks like it could be). Hope this helps! • The first one does the trick! The foreach loop looks more elegant than a for loop. I'm just so used to using for loops, I forgot about foreach loops. Unieke nodes is indeed another language, it's dutch. Thank you! – Simon Verbeke Aug 14 '12 at 14:52 I think the associative array approach is good. You could probably get away with: for ($i = 0; $i < count($nodes); $i++) for ($j = 0; $j < count($nodes[$i]);$j++)
$uniekenodes[$nodes[$i][$j]]++;
As incrementing NULL values results in 1.
• It doesn't seem to work properly. $uniekenodes[$nodes[$i][$j]]++; gives me this error: Notice: Undefined index: 12 in include(). If I leave my loop in place, before executing yours it doesn't give the error. – Simon Verbeke Aug 14 '12 at 11:17
• This may work if you use error suppressants. As the OP points out, there are undefined index errors because these keys have not been declared yet. However you should definitely NOT use error suppressants. It is a pretty unique solution though. – mseancole Aug 14 '12 at 14:45
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2019-11-20 23:45:39
|
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http://bims.iranjournals.ir/article_768.html
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# The augmented Zagreb index, vertex connectivity and matching number of graphs
Document Type : Research Paper
Authors
1 Department of Mathematics, National University of Computer and Emerging Sciences, B-Block, Faisal Town, Lahore, Pakistan.
2 Department of Mathematics, National University of Computer and Emerging Sciences, B-Block, Faisal Town, Lahore, Pakistan.and Department of Mathematics, College of Sciences, University of Sharjah, Sharjah, United Arab Emirates.
Abstract
Let $\Gamma_{n,\kappa}$ be the class of all graphs with $n\geq3$ vertices and $\kappa\geq2$ vertex connectivity. Denote by $\Upsilon_{n,\beta}$ the family of all connected graphs with $n\geq4$ vertices and matching number $\beta$ where $2\leq\beta\leq\lfloor\frac{n}{2}\rfloor$. In the classes of graphs $\Gamma_{n,\kappa}$ and $\Upsilon_{n,\beta}$, the elements having maximum augmented Zagreb index are determined.
Keywords
Main Subjects
#### References
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B. Furtula, A. Graovac and D. Vukicevic, Augmented Zagreb index, J. Math. Chem. 48 (2010), no. 2, 370{380.
I. Gutman, B. Furtula, M. B. Ahmadi, S. A. Hosseini, P. S. Nowbandegani and M. Zarrinderakht, The ABC index conundrum, Filomat 27 (2013), no. 6, 1075{1083.
I. Gutman and B. Furtula (Eds.), Novel Molecular Structure Descriptors-Theory and Applications vols. I-II, Univ. Kragujevac, Kragujevac, 2010.
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F. Harary, Graph Theory, Addison-Wesley, Philippines, 1969.
S. A. Hosseini, M. B. Ahmadi and I. Gutman, Kragujevac trees with minimal atom-bond connectivity index, MATCH Commun. Math. Comput. Chem. 71 (2014), no. 1, 5{20.
Y. Huang, B. Liu and L. Gan, Augmented Zagreb index of connected graphs, MATCH Commun. Math. Comput. Chem. 67 (2012), no. 2, 483-494.
W. Karcher and J. Devillers, Practical Applications of Quantitative Structure-Activity Relationships (QSAR) in Environmental Chemistry and Toxicology, Springer, Heidelberg, 1990.
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### History
• Receive Date: 22 March 2014
• Revise Date: 07 February 2015
• Accept Date: 07 February 2015
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2021-01-20 00:17:42
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https://www.wisdomjobs.com/e-university/financial-management-tutorial-289/ebit-eps-analysis-6651.html
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# EBIT-EPS Analysis - Financial Management
## EBIT and EPSAnalysis
An analytical technique called EBIT-EPS analysis can be used to help determine when debt financing is advantageous and when equity financing is advantageous.
Consider the Yuma Corporation with a present capital structure consisting only of common stock (35 million shares). Assume that Yuma is considering an expansion and evaluating two alternative financing plans. Plan 1, equity financing, would involve the sale of an additional 15 million shares of common stock at $20 each. Plan 2, debt financing, would involve the sale of$300 million of 10 percent long-term debt.
If the firm adopts Plan 1, it remains totally equity financed. If, however, the firm adopts Plan 2, it becomes partially debt financed. Because Plan 2 involves the use of financial leverage, this financing issue is basically one of whether it is in the best interests of the firm’s existing stockholders to employ financial leverage. Table illustrates the calculation of EPS at two different assumed levels of EBIT for both financing plans. Because the relationship between EBIT and EPS is linear, the two points calculated in Table can be used to graph the relationship for each financing plan, as shown in figure.
In this example, earnings per share at EBIT levels less than $100 million are higher using the equity financing alternative. Correspondingly, at EBIT levels greater than$100 million, earnings per share are higher with debt financing. The $100 million figure is called the EBIT-EPS indifference point. By definition, the earnings per share for the debt and equity financing alternatives are equal at the EBIT-EPS indifference point: EPS (debt financing) = EPS (equity financing) Probability Distribution of EBIT,Travco Manufacturing Company EBIT-EPS indifference point [(EBIT – Id)(1 – T) – Dp]/Nd = [EBIT – Ie)(1 – T) – Dp]/Ne where EBIT is earnings before interest and taxes; Id is the firm’s total interest payments if the debt alternative is chosen; Ie is the firm’s total interest payments if the equity alternative is chosen; and Nd and Ne represent the number of common shares outstanding for the debt and equity alternatives, respectively. The firm’s effective tax rate is indicated as T, and Dp is the amount of preferred dividends for the firm. This equation may be used to calculate directly the EBIT level at which earnings per share for the two alternatives are equal. The data from the example shown in Table yield the EBIT-EPS indifference point: EBIT-EPS Analysis,Yuma Corporation (All Dollar Figures Except Per-Share Amounts Are in Millions of Dollars)* Note that in the equity financing alternative, a 66.67 percent increase in EBIT (from$75 million to $125 million) results in a 66.67 percent increase in earnings per share (from$0.90 to $1.50), or, by Equation , a degree of financial leverage of DFL = 66.67%/66.67% = 1.00 Similarly, in the debt financing alternative, a 66.67 percent increase in EBIT results in a 111.69 percent increase in earnings per share, or a degree of financial leverage of DFL = 111.69%/66.67% = 1.68 Figure EBIT-EPS Analysis,Yuma Corporation A comparable magnification of earnings per share will occur if EBIT declines. This wider variation in earnings per share, which occurs with the debt financing alternative, is an illustration of financial risk, because financial risk is defined as the increased variability in earnings per share due to the firm’s use of debt. All other things being equal, an increase in the proportion of debt financing is said to increase the financial risk of the firm. EBIT-EPS Analysis and Capital Structure Decisions The tools of EBIT-EPS analysis and the theory of an optimal capital structure can help a firm choose an appropriate capital structure. This section uses an example to develop a 5- step procedure designed to assist financial managers in making capital structure decisions. Balboa Department Stores has been 100 percent financed with equity funds since the firm was founded. While analyzing a major expansion program, the firm has decided to consider alternative capital structures. In particular, it has been suggested that the firm should use this expansion program as an opportunity to increase the long-term debt ratio from the current level of 0 percent to a new level of 30 percent. Interest on the proposed new debt will amount to$100,000 per year.
• Step 1:Compute the expected level of EBIT after the expansion. Based on Balboa’s past operating experience and a projection of the impact of the expansion, it estimates its expected EBIT to be $500,000 per year under normal operating circumstances. • Step 2: Estimate the variability of this level of operating earnings. Based on the past performance of the company over several business cycles, the standard deviation of operating earnings is estimated to be$200,000 per year. (Operating earnings are assumed to be normally distributed, or at least approximately so.)
• Step 3: Compute the indifference point between the two financing alternatives. This calculation will determine whether it is preferable to add new debt or to maintain the all -equity capital structure. Using the techniques of EBIT-EPS analysis previously discussed, the indifference point is computed to be $300,000. • Step 4: Analyze these estimates in the context of the risk the firm is willing to assume. After considerable discussion, it has been decided that the firm is willing to accept a 25 percent chance that operating earnings in any year will be below the indifference point and a 5 percent chance that the firm will have to report a loss in any year. To complete this analysis, it is necessary to compute the probability that operating earnings will be below the indifference point, that is, the probability that EBIT will be less than$300,000. This is equivalent on the standard normal curve to the following:
Z = $300,000 –$500,000/$200,000 = –1.0 or 1.0 standard deviation below the mean. The probability that EBIT will be less than 1.0 standard deviation below the mean is 15.87 percent; this is determined from Table V at the end of the book. Therefore, on the basis of the indifference point criterion, the proposed new capital structure appears acceptable. The probability of incurring losses must now be analyzed. This is the probability that EBIT will be less than the required interest payments of$100,000. On the standard normal curve, this corresponds to the following:
z = $100,000 –$500,000/$200,000 = –2.0 or 2.0 standard deviations below the mean. The probability that EBIT will be less than 2.0 standard deviations below the mean is 2.28 percent, as shown in Table V. According to this criterion, the proposed capital structure also seems acceptable. If either or both of these tests had shown the proposed capital structure to have an unacceptable level of risk, the analysis would have been repeated for lower levels of debt than the proposed 30 percent rate. Similarly, because the proposed capital structure has exceeded the standards set by the firm, management might want to consider even higher levels of debt than the proposed 30 percent. • Step 5: Examine the market evidence to determine whether the proposed capital structure is too risky. This evaluation should be made in relation to the following: the firm’s level of business risk, industry norms for leverage ratios and coverage ratios, and the recommendations of the firm’s investment bankers. This step is undertaken only after a proposed capital structure has met the “internal” tests for acceptability. Financial leverage is a double -edged sword: It enhances expected returns, but it also increases risk. If the increase in perceived risk is greater than the increase in expected returns, the firm’s weighted cost of capital may rise instead of fall, and the firm’s stock price and market value will decline. It is important to note that a firm need not feel constrained by industry standards in setting its own capital structure. If, for example, a firm has traditionally been more profitable than the average firm in the industry, or if a firm’s operating income is more stable than the operating income of the average firm, a higher level of financial leverage can probably be tolerated. The final choice of a capital structure involves a careful analysis of expected future returns and risks relative to other firms in the industry. EBIT-EPS Analysis and Stock Prices An important question arising from EBIT-EPS analysis is the impact of financial leverage on the firm’s common stock price. Specifically, which financing alternative results in the higher stock price? Returning to the Yuma Corporation example discussed earlier, suppose the company is able to operate at the$125 million EBIT level. Then, if the company chooses the debt financing alternative, its EPS will equal $1.63, and if it chooses the equity alternative, its EPS will be$1.50.
But the stock price depends on the price–earnings (P/E) ratio that the stock market assigns to each alternative. Suppose the stock market assigns a P/E ratio of 16.0 to the company’s common stock if the equity alternative is chosen and a P/E ratio of 15.4 if the debt alternative is chosen. Recalling from Chapter that the P/E ratio (Equation) was defined as the market price per share of common stock (P0) divided by the current earnings per share (EPS), the common stock price can be calculated for both alternatives as follows:
These calculations show that in this case the stock market places a higher value on the company’s stock if the debt alternative is chosen rather than the equity alternative. Note that the stock market assigned a slightly lower P/E ratio to the debt alternative. The stock market recognized the increased financial risk associated with the debt alternative, but this increased risk was more than offset by the increased EPS possible with the use of debt.
To carry the Yuma Corporation example one important step further, suppose the company, while operating at the $125 million EBIT level, chooses an even higher level of debt in its capital structure significantly increases the company’s financial risk—to the point where bankruptcy could occur if EBIT levels turned downward in a recession. If the stock market assigns a P/E ratio of 10.0, for example, the stock price would be$22.50 (= \$2.25 _ 10.0), and it would be clear that this change in capital structure is not desirable.
It is important to emphasize that the P/E ratios in the preceding example are simply assumptions. As an analytical technique, EBIT-EPS analysis does not provide a complete solution to the optimal capital structure question.
In summary, the firm potentially can show increased earnings to its stockholders by increasing its level of financial risk. However, because increases in risk tend to increase the cost of capital (which is analogous to a decrease in the P/E ratio), the firm’s management has to assess the trade -off between the higher earnings per share for its stockholders and the higher costs of capital.
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2019-05-23 05:17:34
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https://v0-4.p2p.today/javascript/tutorial/sync.html
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# Sync Socket¶
This is an extension of the mesh_socket() which syncronizes a common Object(). It works by providing an extra handler to store data. This does not expose the entire Object() API, but it exposes a substantial subset, and we’re working to expose more.
Note
This is a fairly inefficient architecture for write intensive applications. For cases where the majority of access is reading, or for small networks, this is ideal. For larger networks where a significant portion of your operations are writing values, you should wait for the chord socket to come into beta.
## Basic Usage¶
There are three limitations compared to a normal Object().
1. Keys and values must be translatable to a Buffer()
2. Keys and values are automatically translated to a Buffer()
3. By default, this implements a leasing system which prevents you from changing values set by others for a certain time
You can override the last restriction by constructing with leasing set to false, like so:
> const sync = require('js2p').sync;
> let sock = new sync.sync_socket('0.0.0.0', 4444, false);
The only API differences between this and mesh_socket() are for access to this dictionary. They are as follows.
### get()¶
A value can be retrieved by using the get() method. This is reading from a local Object(), so speed shouldn’t be a factor.
> let foo = sock.get('test key', null) // Returns null if there is nothing at that key
> let bar = sock.get('test key') // Returns undefined if there is nothing at that key
It is important to note that keys are all translated to a Buffer() before being used.
### set()¶
A value can be stored by using the set() method. These calls are O(n), as it has to change values on other nodes. More accurately, the delay between your node knowing of the change and the last node knowing of the change is O(n).
> sock.set('test key', 'value');
> sock.set('测试', 'test');
Like above, keys and values are all translated to Buffer() before being used
This will raise an Error() if another node has set this value already. Their lease will expire one hour after they set it. If two leases are started at the same UTC second, the tie is settled by doing a string compare of their IDs.
Any node which sets a value can change this value as well. Changing the value renews the lease on it.
### del()¶
Any node which owns a key, can clear its value. Doing this will relinquish your lease on that value. Like the above, this call is O(n).
> sock.del('test');
### update()¶
The update method is simply a wrapper which updates based on a fed Object(). Essentially it runs the following:
> for (var key in update_dict) {
... sock.set(key, update_dict[key]);
... }
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2021-09-22 04:47:21
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https://physics.stackexchange.com/questions/448750/proof-that-pressure-rises-in-a-fixed-control-volume
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# Proof that pressure rises in a fixed control volume
I am looking for a proof using Bernoulli's equation that that for $$Q=(Area)(Velocity)$$, $$Q_{in}>Q_{out} \Rightarrow P_{inside}>P_{outside}$$. I read that for a computer, if the case fans blow a higher volumetric flow rate in than out, then the PC case is positive pressure, however I seem unable to prove this. My attempt is shown below, with the assumption that $$z_1=z_2$$, $$P_{1,g}=0$$, and the subscript g indicates gage pressure. My control volume is the inside of a computer case, and subscript 1 represents outside of the control volume (flowing in), and subscript 2 represents inside the control volume (flowing out):
\begin{align} \frac{P_1}{\rho}+\frac{V_1^2}{2}+z_{1}&=\frac{P_2}{\rho}+\frac{V_2^2}{2}+z_{2} \\ \frac{V_1^2}{2}&=\frac{P_{2,g}}{\rho_{air}}+\frac{V_2^2}{2} \Rightarrow \\ \frac{P_{2,g}}{\rho_{air}}&=\frac{V_1^2-V_2^2}{2} \Rightarrow \\ P_{inside,g}&=\rho_{air} \frac{V_{entering}^2-V_{leaving}^2}{2} \end{align}
Since $$V=\frac{Q}{A}$$, then the pressure inside is also dependent on the area of a fan, which contradicts what I read saying $$Q_{in}>Q_{out} \Rightarrow P_{inside}>P_{outside}$$. This is a bit confusing to me and I'd appreciate any answers that I can get.
• Can you define more of your notation? What does the $g$ subscript represent, and are $1$ and $2$ the same as "in" and "out" respectively? – Aaron Stevens Dec 17 '18 at 2:16
• Are you assuming that the air is incompressible? You must not be assuming this, because, otherwise Qin=Qout. Also. Is the fan inside the control volume or outside? – Chet Miller Dec 17 '18 at 2:34
• Is heat being released within the control volume? – Chet Miller Dec 17 '18 at 2:55
• In the particular case you mentioned Bernoulli equation is not applicable because viscous effects are dominant. – Deep Dec 17 '18 at 5:12
• @Josh Can you give the source of where you read it plz ? – J.A Dec 17 '18 at 9:38
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2019-07-17 10:47:15
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http://clay6.com/qa/74945/a-positively-charged-particle-is-released-from-rest-in-an-unifrom-electric-
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Answer
Comment
Share
Q)
# A positively charged particle is released from rest in an unifrom electric field . The electric potential energy of the charge
$\begin{array}{1 1} \text{remains a constant because the electric field is uniform } \\ \text{increases because the charge moves along the electric field } \\ \text{decreases because the charge moves along the electric field} \\ \text{decreases because the charge moves opposite to the electric field } \end{array}$
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2020-08-09 00:18:14
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https://asmedigitalcollection.asme.org/medicaldevices/article-abstract/10/3/030921/377151/Designing-an-Affordable-Wire-Navigation-Surgical?redirectedFrom=fulltext
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Orthopedic residency training is in the midst of a paradigm shift. In 2012, the Residency Review Committee (RRC) for Orthopaedic Surgery and the American Board of Orthopaedic Surgery (ABOS) mandated that there must be structured motor skills training for first-year residents [1]. Taking from other disciplines such as laparoscopic surgery, surgical simulators have emerged as the tools by which first-year orthopedic residents can practice and acquire these motor skills. However, in a 2011 national survey of program directors and residents, it was shown that one of the greatest barriers to training residents was cost [2]. This study further showed that most programs would only be able to afford a simulator costing between $1000 and$15,000. This is a contrast to many virtual reality simulators currently available, which can easily cost upward of \$100,000.
In its mandate, the ABOS also defined a...
## References
References
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ACGME, 2014, “ACGME Orthopaedic Surgery Requirements,” Accreditation Council for Graduate Medical Education, Chicago, IL, Last accessed Oct. 26, 2015, http://www.acgme.org/acgmeweb/tabid/140/ProgramandInstitutionalAccreditation/SurgicalSpecialties/OrthopaedicSurgery.aspx
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2019-10-22 09:55:02
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https://www.impetus-afea.com/support/manual/?command=MAT_FABRIC
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#### Command list
• Input handling
• Solution control and techniques
• Output
• Mesh commands
• Nodes and connectivity
• Material properties
• Initial conditions
• Boundary conditions
• Contact and tied interfaces
• Rigid bodies
• Connectors
• Parameters and functions
• Geometries
• Sets
• Coordinate system
• Particle
• SPH
### MAT_FABRIC
###### Material properties
*MAT_FABRIC
"Optional title"
mid, $\rho$, $E$, $\nu$
$E_f$, $\epsilon_l$, $\epsilon_{f0}$, $\epsilon_{f1}$, $\epsilon_e$, $\sigma_y$, $K_n$, $n$
$\alpha_1$, $\alpha_2$, $\alpha_3$, $\alpha_4$, $\eta_1$, $\eta_2$, $\eta_3$, $\eta_4$
$\mu$, $\xi$, $c$, $\dot{\epsilon}_0$, $W_c$
#### Parameter definition
VariableDescription
mid Unique material identification number
$\rho$ Density
$E$ Young's modulus (matrix)
$\nu$ Poisson's (matrix)
$E_f$ Fiber stiffness
$\epsilon_l$ Fiber locking strain (woven fabrics)
$\epsilon_{f0}$ Strain where fibers begin to fail
$\epsilon_{f1}$ Strain where all fibers have failed
$\epsilon_e$ Element erosion strain
$\sigma_y$ Matrix yield stress
$K_n$ Optional non-linear bulk stiffness parameter
$n$ Optional non-linear bulk stiffness exponent
$\alpha_1$ Fiber angle 1
$\alpha_2$ Fiber angle 2
$\alpha_3$ Fiber angle 3
$\alpha_4$ Fiber angle 4
$\eta_1$ Fiber fill fraction 1
$\eta_2$ Fiber fill fraction 2
$\eta_3$ Fiber fill fraction 3
$\eta_4$ Fiber fill fraction 4
$\mu$ Dynamic viscosity
$\xi$ Initial stiffness (fraction of fiber stiffness)
$c$ Strain rate parameter
$\dot{\epsilon}_0$ Reference strain rate
$W_c$ Matrix failure parameter
default: no matrix failure
#### Description
This is a model for fiber reinforced composites. Fibers can be defined in up to four different directions. Fiber stress, damage and failure is computed individually for each fiber direction.
A fiber stress, $\sigma_i$, is calculated as:
$\sigma_i = \left\{ \begin{array}{lcl} \displaystyle{ sf \cdot \xi \cdot \epsilon_i } & : & \epsilon_i \leq 0 \\ \displaystyle{ sf \cdot \left( \frac{1-\xi}{2} \cdot \frac{\epsilon_i^2}{\epsilon_l} + \xi \cdot \epsilon_i \right) } & : & 0 \lt \epsilon_i \leq \epsilon_l \\ \displaystyle{ sf \cdot \left( \frac{\xi-1}{2} \cdot \epsilon_l + \epsilon_i \right) } & : & \epsilon_i \gt \epsilon_l \end{array} \right.$
where:
$sf = \left(1-D_i^2\right) \cdot E_f$
$\xi$ is the ratio between initial and full tensile stiffness for the in-plane directions. $\epsilon_i$ is the fiber strain in the direction $i$ and $\epsilon_i$ is the locking strain. $\epsilon_l$ is used when modeling weaves, where initial straining of the material leads to realigning of the fibers rather than strething. $\eta_i$ is the volume fraction fibers and $D_i$ is the fiber damage level which grows irreversibly from 0 to 1:
$D_i = \left\{ \begin{array}{lcl} \displaystyle{ 0 } & : & \epsilon_i^{max} \leq \epsilon_{f0} \\ \displaystyle{ \frac{\epsilon_i^{max} - \epsilon_{f0}}{\epsilon_{f1} - \epsilon_{f0}} } & : & \epsilon_{f0} \lt \epsilon_i^{max} \leq \epsilon_{f1} \\ \displaystyle{ 1 } & : & \epsilon_i^{max} \gt \epsilon_{f1} \\ \end{array} \right.$
where $\epsilon_i^{max}$ is the largest tensile strain the fibers have experienced. $\epsilon_{f0}$ defines when fibers begin to fail and $\epsilon_{f1}$ defines when all fibers have failed. The failure strains can be defined to be strain rate dependent:
$\displaystyle{ \epsilon_{f0}^{sr} = \epsilon_{f0} \cdot \left(1 + \frac{\dot{\epsilon}_i}{\dot{\epsilon}_0} \right)^c }$
$\displaystyle{ \epsilon_{f1}^{sr} = \epsilon_{f1} \cdot \left(1 + \frac{\dot{\epsilon}_i}{\dot{\epsilon}_0} \right)^c }$
The pressure in the material is calculated as:
$p = \left\{ \begin{array}{lcl} \displaystyle{ -K \cdot \epsilon_v } & : & \epsilon_v \geq 0 \\ \displaystyle{ -K \cdot \epsilon_v + \sum_{i = 1}^4 \eta_i \cdot K_n \cdot \vert \epsilon_v \vert ^n } & : & \epsilon_v \lt 0 \\ \end{array} \right.$
where $K$ is the bulk modulus of the matrix and $K_n$ and $n$ are input parameters controlling the non-linear response in compression.
The total stress in the material is defined as:
$\displaystyle{ \mathbf{\sigma} = 2 G \mathbf{\epsilon}_{dev}^e - p \mathbf{I} + \sum_{i=1}^4 \eta_i \sigma_i \mathbf{v}_i \otimes \mathbf{v}_i + 2 \mu \dot{\mathbf{\epsilon}}_{dev} }$
where $\mathbf{\epsilon}_{dev}^e$ is the deviatoric elastic strain in the matrix material, $\dot{\mathbf{\epsilon}}_{dev}$ is the total deviatoric strain rate and $\mathbf{v}_i$ is a fiber direction.
Matrix damage evolves with plastic flow in tension:
$\displaystyle{\dot D = \frac{\mathrm{max}(0, \sigma_1) \cdot \dot\varepsilon_{eff}^p}{W_c}}$
$\sigma_1$ is the maximum principal stress in the matrix and $\dot\varepsilon_{eff}^p$ is the effective plastic strain rate. The matrix loses its ability to carry shear loads when $D=1$.
The initial fabric orientation needs to be defined using either INITIAL_MATERIAL_DIRECTION, INITIAL_MATERIAL_DIRECTION_VECTOR or INITIAL_MATERIAL_DIRECTION_WRAP.
#### Example
*UNIT_SYSTEM
SI
*PARAMETER
s = 0.05, "stand-off distance"
d = 0.05, "charge diameter"
h = 0.01, "charge thickness, h=1cm is 36g for 5cm diameter"
tend = 0.01
*TIME
[%tend]
*OUTPUT_SENSOR
"Center"
1, 1, 0.0, 0.0, -0.024
*INCLUDE
mesh.k
*CHANGE_P-ORDER
ALL, 0, 3
*PART
"Dyneema"
1, 1
"Rig"
2, 2
*MAT_FABRIC
"Dyneema"
1, 980.0, 5.0e8, 0.45
115.0e9, 0.0, 0.037, 0.037, 1.0, 20.0e6, 400.0e9, 1.5
0, 90, 0, 0, 0.415, 0.415, 0, 0
250.0, 0.125, 0.05, 100.0
*INITIAL_MATERIAL_DIRECTION_VECTOR
1, P, 1
1, 0, 0, 0, 1, 0
*MAT_RIGID
"Rig"
2, 7850
*BC_MOTION
"Rig"
1
P, 2, XYZ, XYZ
*CONTACT
"All to all"
1
ALL, 0, ALL, 0, 0.4
*PARTICLE_DOMAIN
ALL, 0, 100000
-0.3, -0.3, -0.2, 0.3, 0.3, 0.2
*PARTICLE_AIR
1,
AIR, 1
*PARTICLE_HE
2,
PETN, 2
*GEOMETRY_BOX
"Air"
1
-0.3, -0.3, -0.2, 0.3, 0.3, 0.2
*GEOMETRY_PIPE
"Charge"
2
0.0, 0.0, [%s], 0.0, 0.0, [%s+%h], [%d/2]
*PARTICLE_DETONATION
"Booster"
1
0.0, 0.0, [%s+%h/2]
*END
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2021-02-25 10:24:50
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https://scicomp.stackexchange.com/tags/c%2B%2B/hot?filter=year
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# Tag Info
13
If you have constants that will not change before runs, declare them in a header file: //constants.hpp #ifndef PROJECT_NAME_constants_hpp #define PROJECT_NAME_constants_hpp namespace constants { constexpr double G = 6.67408e-11; constexpr double M_EARTH = 5.972e24; constexpr double GM_EARTH = G*M_EARTH; } #endif //main.cpp using namespace ...
12
I was able to reproduce the behavior reported in the question, and traced the observed inaccuracies to the following line: return y*sin(pi<Real>()*x)/pi<Real>(); The explicit multiplication with a floating-point approximation of π introduces a small error into the argument to sin, which comprises the representational error in the constant and ...
12
Another alternative that may be in line with your train of thought is to use a namespace (or nested namespaces) to properly group constants. An example might be: namespace constants { namespace earth { constexpr double G = 6.67408e-11; constexpr double Mass_Earth = 5.972e24; constexpr double GM = G*Mass_Earth; }// constant properties ...
7
The 14th order methods due to Feagin can be found in DifferentialEquations.jl. An example using them with 128-bit floating point arithmetic is as follows: using OrdinaryDiffEq, DoubleFloats function lorenz(du,u,p,t) du[1] = 10.0(u[2]-u[1]) du[2] = u[1]*(28.0-u[3]) - u[2] du[3] = u[1]*u[2] - (8/3)*u[3] end u0 = [1.0;0.0;0.0] tspan = (0.0,100.0) prob = ...
5
I have looked at your simple code example, and my suspicion is that what you observe in loss of speed is due to the C-heritage requirement that right-hand side expressions be evaluated using intermediate double precision operations, even when the source variables are single precision and the output location (left-hand side destination) is single precision. ...
4
Numpy has a file format that is pretty simple, which makes it perfectly compatible with basically every other high level language. (https://www.numpy.org/devdocs/reference/generated/numpy.lib.format.html) It looks like the format is much lighter than boost or hdf5. The docs say it should be easy enough to write a parser yourself, if necessary, which I would ...
4
I don't recommend it, but not because of performance issues. It will be a little less performant than a traditional matrix, which are usually allocated as a big chunk of contiguous data that is indexed using a single pointer dereference and integer arithmetic . The reason for the performance hit is mostly caching differences, but once your matrix size gets ...
4
There are multiple possible explanations: with floats and doubles the different number of computations happen due to, say, number of iterations/function evaluations (or something else, as pointed out by @Richard in the comments) there is some type conversions/implementations (say templated code) that are non-optimal with float types as opposed to doubles. I ...
3
I can only give you my personal impressions and opinions. My impression is that many people find the class somewhat redundant, because functionally it doesn't really give you much that the vector class doesn't. The algorithms it implements will have the same asymptotic complexity, although optimizations can in principle be made, because it restricts the type ...
3
I think you need to know that when you discretize a volume by using tetrahedral meshes, you will get just an approximation of your perfect surfaces because of triangulation. You started with STEP file format, which is NOT a mesh format, but it's a CAD format. The difference between CAD formats and mesh formats is that CAD formats like STEP, IGES, SAT, etc. ...
3
The goal is to compute an $x\in\mathbb{R}^{n}$ to satisfy the strict inequalities $$f(z_{i})^{T}x>0\qquad\forall z_{i}\in\{1,\ldots,m\}.\tag{1}$$ If we write $\epsilon>0$ as the smallest margin of feasibility, that is $$\epsilon=\min_{i}\{f(z_{i})^{T}x\},$$ then (1) is equivalent to $$f(z_{i})^{T}x\ge\epsilon>0\qquad\forall z_{i}\in\{1,\ldots,... 3 So, you are comparing a generally slower Matlab implementation of algorithm A to a generally faster C++ implementation of algorithm B, and still getting the advantage for A. I would say, congratulations, you certainly have a stronger point now, since the "competing" algorithm is given an advantage. It's worth no note though, that implementation in C++ is ... 2 Using the recurrence step and the normalized incomplete gamma function definition I simplified the formula to:$$\theta e^{k \log \left(\frac{o}{\theta }\right)-\frac{o}{\theta }- \ln{\Gamma (\kappa)}} +\theta \kappa Q \left(\kappa,\frac{o}{\theta }\right)-o Q \left(\kappa,\frac{o}{\theta }\right)+o+s$$In this equation Q stands for the normalized ... 2 The library Boost.Numeric.uBlas recently added a tensor extension which is shipped with Boost version 1.70. Please have a look at https://github.com/boostorg/ublas. It provides standard matrix and tensor operations with runtime-variable order (number of dimensions), dimensions for the first- and last-order storage formats (column- and row-major). You can ... 2 Cereal is a straight-forward and easy-to-use serialization library for C++ data structures. It knows all of the STL data structures and adapting custom classes for use with it is easy. Example code: #include <cereal/types/unordered_map.hpp> #include <cereal/types/memory.hpp> #include <cereal/archives/binary.hpp> #include <fstream> ... 2 You can use boost's serialization facilities, which can be straightforwardly extended to support custom data structures. If you use Eigen you can adapt something like this in order to suit your needs. 2 Before you start down this path it's important to determine whether there's enough data parallelism in your current code to make using a GPU worthwhile. I'd encourage you to start by describing your application and algorithms in more detail in the question. Depending on the application, there may be computational tasks for which library routines are ... 2 It is recommended to think about parallelization first and then discuss the implementation. Think about what the code does, what data dependencies exist, and what operations can be carried out in parallel. Then there are several C++ frameworks (alpaka, kokkos, or the ArrayFire library mentioned in another answer) that help you to introduce a layer of ... 2 OpenCL is runnable on multicore cpu, intel hd graphics and even DSP cards. It was pretty much the standard for cross platform gpu computing until compute shaders were introduced. There are various libraries that have OpenCL as a backend such as viennaCL or ArrayFire. Some of these libraries can use other backends for gpu computation such as CUDA, which runs ... 2 Are you sure it is supposed to be sign function ? According to this https://projects.coin-or.org/ADOL-C/browser/stable/2.1/ADOL-C/doc/adolc-manual.pdf?format=raw in section 1.8, condassign(a,b,c,d) is equal to a = (b > 0) ? c : d So the function posted is actually giving Heaviside function and not the sign function. It implements this function$$ f(x) =...
2
Here are two considerations that might help you figure out whether a solution exists: First, if there is a vector $X$ so that $F(z_i) \cdot X > 0$, then all vectors $Y=\alpha X$ for any choice of $\alpha>0$ are also solutions because $F(z_i) \cdot Y = \alpha \underbrace{(F(z_i)\cdot X)}_{\ge 0} > 0$. In other words, if a solution exists, then there ...
2
The solution I found for PETSc 3.7 was to use MatGetSubMatrices. Warning : this method is not present in the last API. I discovered that BAIJ is actually not intended for block matrices but rather to keep rows by group when distributing the matrix over processors. Thus I used AIJ format. (MPIAIJ to get a parallel matrix). First have the rights rows and ...
1
For anyone interested in this problem, I found the following solution: #include "itensor/all.h" using namespace itensor; int main() { int N = 100; // // Initialize the site degrees of freedom. // auto sites = SpinHalf(N,{"ConserveQNs=",false}); //make a chain of N spin 1/2's //Transverse field Real h = 4.0; // //...
1
I would second the opinion expressed in the context. For that small problem and limited usage, you don't need a library. Generation of a structured grid and retrieving points can be coded up in at most several screens of code. However, I would point out for you ViennaGrid library, which can be used and actually provides STL iterators. In addition, the ...
1
Definitely use C++ and Eigen. Reasons: Sounds like it fits best for your case. Eigen beats LAPACK using optimization flags (-O3) and a good compiler (GCC, Clang). At least for most tests I recently performed (dense linear algebra) Once you debug your application use the -ffast-math compiler flag for a huge speedup, but test your output to see if it remains ...
1
One way that I do is to use singleton. When you start your program you initiate your singleton and fill it with the constant data (probably from a properties file that you have for the run). You get this in every class that you need the values and just use it.
1
OP's comment on OP: yes,numbers are intergers For arbitrarily large integer calculations, MAPLE is an option worth trying. it has very efficient implementations for a number of such calculations.
1
If you have a structured way of enumerating the graphs you wish to calculate the determinants of, perhaps you could find low-rank updates which transfer you from one graph to another. If so, then you could use the matrix determinant lemma to cheaply calculate the determinant of the subsequent graph to be enumerated using your knowledge of the current graph'...
1
I also write a benchmark. For matrix of small size (<100*100), the performance is similar for vector< vector< double>> and wrapped 1D vector. For matrix of large size (~1000*1000), wrapped 1D vector is better. The Eigen matrix behaves worse. It is surprise to me that the Eigen is the worst. #include <iostream> #include <iomanip> #...
Only top voted, non community-wiki answers of a minimum length are eligible
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2020-01-26 15:10:33
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http://xml.jips-k.org/full-text/view?doi=10.3745/JIPS.04.0193
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Alshammari* , El-Ghany** *** , and Shehab* ***: Big IoT Healthcare Data Analytics Framework Based on Fog and Cloud Computing
# Big IoT Healthcare Data Analytics Framework Based on Fog and Cloud Computing
Abstract: Throughout the world, aging populations and doctor shortages have helped drive the increasing demand for smart healthcare systems. Recently, these systems have benefited from the evolution of the Internet of Things (IoT), big data, and machine learning. However, these advances result in the generation of large amounts of data, making healthcare data analysis a major issue. These data have a number of complex properties such as high-dimensionality, irregularity, and sparsity, which makes efficient processing difficult to implement. These challenges are met by big data analytics. In this paper, we propose an innovative analytic framework for big healthcare data that are collected either from IoT wearable devices or from archived patient medical images. The proposed method would efficiently address the data heterogeneity problem using middleware between heterogeneous data sources and MapReduce Hadoop clusters. Furthermore, the proposed framework enables the use of both fog computing and cloud platforms to handle the problems faced through online and offline data processing, data storage, and data classification. Additionally, it guarantees robust and secure knowledge of patient medical data.
Keywords: Cloud Computing , Fog Computing , E-Health , Electronic Health Records , Healthcare Data Analytics , Internet of Things (IoT)
## 1. Introduction
While the concept of e-health is still in its infancy throughout the world, e-health has gained prominence in many countries over the last few decades. Recently, with the aid of information technology, many researchers [1-10] have been motivated to address the digital transformation of medical data. In many healthcare organizations, there are huge amounts of heterogeneous medical data within electronic health records (EHRs). EHR data must be collected, integrated, cleaned, stored, analyzed, and interpreted in efficient ways that will ensure accuracy and streamline access time [1]. In healthcare systems, making decisions demands the careful analysis of large amounts of real-time data collected from sensors and wearable devices. These decisions have a significant influence on patient health. For example, a smart city’s healthcare systems could monitor their patients remotely and intervene when patients engage in activities that may lead to poor health. Many researchers utilize Internet of Things (IoT) wearable devices to detect signals that may identify different diseases [2]. On the other hand, machine learning methods are becoming increasingly popular due to their excellent performance [3,4].
In the field of healthcare data analytics, there are generally four main categories: descriptive, diagnostic, predictive, and prescriptive analytics [1]. Descriptive analytics aims to identify the present status of a patient and generate such information as reports, charts, and histograms. Many analytic tools could be used to perform this type of analysis.
Diagnostic analysis depends on clustering techniques and decision trees to understand reasons for the reappearance of some specific diseases in individual patients, and it studies the occurrence of events and factors that trigger them. Predictive analytics depends on different machine learning algorithms to predict unknown events by building a suitable predictive model. Prescriptive analytics tries to make optimal decisions by proposing effective actions that lead to suitable patient treatments. The increasingly large amounts of healthcare data create an inevitable need for big data frameworks with suitable analysis tools. Significant research has been published to target this objective, focusing on areas such as infrastructure, data management, data searching, data mining, and data security.
This paper introduces a new approach to e-health, which enriches IoT, cloud computing, and fog computing for big healthcare data analysis using cognitive data mining and machine learning algorithms. Instead of centralized healthcare data processing, which is an obstacle to large-scale data analysis, fog computing helps us to perform data processing over distributed fog nodes. Furthermore, this article describes the design component analysis of the framework architecture in detail. The main objective of this work is to improve the efficiency and effectiveness of healthcare services. In this paper, we aim to provide scalability in IoT wearable devices, and minimize the communication overhead between network fog and cloud layers. The proposed e-health framework, using the best regulated analytics pipeline, will benefit from the current communication revolution to unify EHRs and enable remote medical data sharing. Additionally, the proposed framework aims to create more stable and effective communication with patients, and to upgrade healthcare services by predicting and potentially preempting illnesses through integrating EHR and sensory data obtained from 24/7 monitoring. Additionally, the proposed framework would provide timely assistive recommendations to patients. This would alleviate clinician overload, help an ageing population that needs long-term care, improve data access, and reduce medical errors. This in turn would reduce pressure on national healthcare budgets.
The paper is organized as follows: Section 2 presents a literature review and related work. The proposed framework’s overall architecture and their layers are discussed in detail in Section 3. Section 5 presents remarks and discussion with a comparison between the proposed framework and some recent related frameworks. Finally, the conclusion and future work are presented in Section 5.
## 2. Literature Review
In the last few years, many researchers [1-10] have been inspired to write about big data and fields related to big data. At the same time, many machine learning algorithms [3,4] that can extract and analyze large amounts of data have been utilized to help decision makers. Platforms have been built to help analyze huge amounts of IoT data. Moreover, in medical big data analytics, computational issues have arisen due to the streaming nature and high dimensionality of healthcare data. Aktas et al. [5] presented a platform for data analytics based on IoT. Their proposal was very focused on metadata only and lacks automatic indexing and partitioning. This method works best for social unstructured data. Khan et al. [4] proposed a real-time big data analytics framework. This framework focused only on data volume and velocity and considered these two aspects without supporting a variety of data sources. Shen et al. [6] proposed a classification model called oriented feature selection support vector machine (OFSSVM) for cancer prediction using gene expression data. Based on gene order, they demonstrated binary classifi¬cation and multiclass classification effectiveness. However, this study lacked overall interoperability between their proposed components.
Mishu [7] proposed a framework for biomedical engineering applications using C-means clustering. Their framework has the potential to help clinicians and patients. They used the University of California–Irvine (UCI) machine learning repository and MapReduce to analyze diseases and their symptoms. Al-Khafajiy et al. [8] proposed a fog-driven IoT model based on an unsupervised deep feature learning method. The model aimed to derive a general purpose patient representation from EHRs. They used random forest classifiers trained over a 200,000 patient dataset. Alhussain [9] proposed an architectural framework of big data healthcare analytics with a focus on the importance of security and privacy issues. Images, signals, and genome data processing play key roles in healthcare data analyses. Yousefpour et al. [10] presented an analytics framework called smart health with the aim of reducing IoT service delay via fog offloading and resolving the challenges facing big healthcare data through information and communication technologies (ICT). In recent years, social networks have become a platform for data exchange through which users with common needs can share their data.
## 3. Materials and Methods
The proposed system will be based on multisensory devices, which are responsible for tracking known disease symptoms. Smart wearable devices will provide users with overall health data and notifications from sensors to their mobile phones. In addition, machine learning algorithms such as SVM, bagged SVM (BSVM), and deep learning models will be utilized to improve performance accuracy and time.
The research methodology used follows the common big data analytics pipeline process that starts with data acquisition, followed by data cleaning, annotation, and extraction. Thereafter, the system integrates the medical data to generate the analytical model. Finally, medical data interpretation and visualization occurs. The system promises a novel solution for the data integration problem. The proposed method efficiently addresses the data heterogeneity problem using middleware between heterogeneous data sources and MapReduce Hadoop clusters. It also utilizes recent machine learning algorithms to improve accuracy and data access time. Furthermore, it guarantees robust and secure knowledge of patient medical data.
Fog computing nodes have the benefit of utilizing resources efficiently. Fog nodes are constantly processing incoming IoT streams from wearable devices. These nodes rely on a number of virtual machines responsible for transferring the pre-processed data to the cloud computing layer for further processing [8]. On the other hand, cloud computing comprises many services such as infrastructure as a service (IaaS), platform as a service (PaaS), software as a service (SaaS), and utility services. IaaS, for example, offers access to unlimited cloud storage space while PaaS is responsible for executing resource intensive applications. SaaS manages access to different software and utility services and stores large amounts of data for remote access. Fog computing is essential for big real-time data processing collected from IoT sensors. Furthermore, fog computing is a critical step in our proposed framework as a basis for both processing and storing data in the cloud computing system. In this way, the proposed framework becomes capable of avoiding latency caused by the transport communication layer in the cloud computing system. In healthcare applications, continuous multi-wearable device sensor data streams rapidly form a massive dataset. Therefore, it is necessary to employ fog computing nodes to handle these data accurately in real time.
##### 3.1 Framework Design Components
Fig. 1 shows the overall architecture of our proposed layered framework. It is based on healthcare big data analytics collected from IoT wearable devices with fog computing nodes and a cloud computing system. The framework layer components guarantee multiple device pre-processing, processing, integration, and analytics in real time. As shown in Fig. 1, the fog nodes are closer to the smart wearable device’s physical location, thus some applications must be serviced within specific time slots. The fog nodes deliver the heavy data load to the cloud system that handles the computationally intensive application processing.
Fig. 1.
The generic architecture of the proposed framework is divided into five layers: sensor data acquisition layer, local healthcare service provider layer, healthcare security layer, medical resource management layer, and personalized notification/decision layer.
Fig. 2.
Working steps of the proposed framework.
Fig. 2 shows the process flow of our proposed framework. In abstract, it contains three main blocks: (1) sensing data and pre-processing, (2) feature queuing, selection, and extraction, (3) the predictive model. Data normalization which generalizes the effect of the different data acquired from sensors could be defined in many different forms. Given the data from the sensors noted as [TeX:] $$D_{S}$$ and of size [TeX:] $$n$$, the normalized data [TeX:] $$D_{S}^{*}$$ is obtained by applying the normalization approach. Normalization by root mean square and normalization by maximum and minimum are given by Eqs. (1) and (2), respectively.
##### (1)
[TeX:] $$D_{S}^{*}=\frac{D_{S i}}{\sqrt{\frac{1}{n} \sum_{j=1}^{n} D_{S i}^{2}}}, \quad i \in[0, n]$$
##### (2)
[TeX:] $$D_{S}^{*}=\left(D_{S_{i}}-M i n_{\text {old}}\right) \frac{\operatorname{Max}_{\text {nev}}-\text {Min}_{\text {nev}}}{\operatorname{Max}_{\text {old}}-\operatorname{Min}_{\text {old}}}+\operatorname{Min}_{\text {new}}, \quad i \in[0, n]$$
General feature selection algorithm is shown in Algorithm 1. Many metrics approaches are utilized for such purpose of feature selection. The Gini index, for instance, measures the inequality among values of a frequency distribution which range from 0 (complete equality) to 1 (complete inequality). The Gini coefficient is often calculated according to the Brown formula in Eq. (3) where [TeX:] $$G$$ denotes Gini coefficient, [TeX:] $$X_{i}$$ is cumulated proportion of one feature, and [TeX:] $$Y_{i}$$ is cumulated proportion of target feature. Information gain (IG) is another method for feature selection which based on pioneering work of information theory. It studies the value or “information content” of messages through measuring the number of bits obtained for class prediction. The information gain [TeX:] $$\mathrm{G}(f)$$ of a feature f is given by Eq. (4), where [TeX:] $$\left\{C_{i}\right\}_{i=1}^{n}$$ denotes the set of classes, [TeX:] $$v \in V$$ is the set of possible value of feat [TeX:] $$f$$ which could be generalized to any number of classes.
##### (3)
[TeX:] $$G=\left|1-\sum_{i=1}^{n}\left(X_{i}-X_{i-1}\right)\left(Y_{i}+Y_{i-1}\right)\right|$$
##### (4)
[TeX:] $$G(f)=-\sum_{i=1}^{n} P\left(c_{i}\right) \log P\left(c_{i}\right)+\sum_{v \in V} \sum_{i=1}^{n} P(f=v) P\left(c_{i} \mid f=v\right) \log P\left(c_{i} \mid f=v\right)$$
##### Algorithm 1
General feature selection algorithm
##### Local Healthcare Service Provider Layer
Initially, hospitals, application specific industries, or medical companies are responsible for granting the stakeholders (patients, doctors, clinics, and decision makers) privileges to use the healthcare system. Healthcare data are highly sensitive information; therefore, at this layer, with the aid of the healthcare security layer, user privacy will be maintained.
##### 3.3 Sensor Data Acquisition Layer
The IoT revolution has caused the medical wearable devices sector (and telehealth) to increase and change rapidly. According to a study conducted by Berg Insight in 2014, telehealth devices and services revenue reached \$4.5 billion, which nearly doubled by 2017 [2]. Wearable device categories and revenue are shown in Fig. 3. The priority time [TeX:] $$\left(T_{p}\right)$$ performed at the sensor at local site is given according to Eq. (5) where [TeX:] $$N$$ indicates number of sensors, [TeX:] $$T_{c}$$ denotes time of entire cycle, [TeX:] $$\psi$$ is the Poisson arrival, and [TeX:] $$T_{\text {pac}}$$ is the Packet transmission time.
##### (5)
[TeX:] $$T_{p}=\psi T_{c} * N T_{p a c} / 2\left(1-\psi T_{c}\right)$$
Fig. 3.
Wearable device categories and revenue between 2017 and 2019. Adapted from [ 2].
Recently, there has been continued growth in the number of monitoring devices, such as diabetes care devices, blood pressure monitoring, and heart rate monitors, connected to a cloud data center [2]. Currently, mobile wearable health devices are becoming an important part of any monitoring system, assisting in medical prediction, detection, and diagnosis. The most popular wireless protocols utilized in medical applications are Wi-Fi, ZigBee, and LoRa (Long Range radio). The Wi-Fi protocol allows higher data throughput for low-power applications. However, the ZigBee protocol is ideal as it consumes low power with an advanced communication channel encryption standard. Finally, LoRa is a recent wireless protocol that can cover long distances at low cost with low power consumption [2].
In the proposed framework, medical wearable devices trigger data generation. These data, which are captured from different devices, in turn are delivered to healthcare IoT gateways that mediate between the devices and the fog computing layer. The data acquisition process is achieved through specific IoT protocols that link the wearable devices to the IoT gateways. Machine-to-machine (M2M) and message queuing telemetry transport (MQTT) are well-known examples of such protocols. In our proposed framework, the IoT gateways are also responsible for local processing, storage, control, and filtering of data stream functions. Furthermore, with the aid of the healthcare security layer, device connectivity integrity is ensured through policy-based access enforcement. Continuous monitoring data generates a very large amount of data because the volume, velocity, and variety characteristics are constantly growing. Medical data analytics take an extensive amount of time given the data complexity and volume and the need for preprocessing, cleaning, filtering, and classification tasks.
##### 3.4 Fog Computing Nodes
The fog computing nodes mediate between the wearable devices and the cloud system. They accelerate the analysis process, which is mandatory in time-sensitive applications [10]. The fog nodes receive unstructured data and do not use any predefined model. They provide data pre-processing, pattern mining, classification, prediction, and visualization. The data pre-processing stage includes error, redundancy, and outlier handling. Furthermore, all received IoT data streams have to be translated into a structured model through parsing and filtration by the fog nodes. Once we have the structured model, pattern mining approaches are used on the resulting data to build correlations and association maps. The equations for average energy consumption for transmitting and receiving fog node are illustrated in both Eqs. (6) and (7), respectively. If two Fog nodes [TeX:] $$F_{x}$$ and [TeX:] $$F_{y}$$ need to share resources together, the power needed to propagate the data is mainly based on the distance [TeX:] $$D_{x y}$$ between [TeX:] $$F_{x}$$ and [TeX:] $$F_{y}$$ nodes. The data transmitting rate at fog node [TeX:] $$F_{x}$$ is given by Eq. (8) and denoted as [TeX:] $$\text { Rate }{ }_{F_{x}}^{s}$$ and at the receiver side as [TeX:] $$\text { Rate }_{F y}^{r}$$ at node [TeX:] $$F_{y}$$ as given in Eq. (9).
##### (6)
[TeX:] $$E n_{F_{x}}^{s}=b^{\uparrow} * S_{i} *\left(T_{p}+\left(D_{x y} * E n_{s h}\right)\right)$$
##### (7)
[TeX:] $$E n_{F_{y}}^{r}=b^{\downarrow} * S_{i} * E n_{s h}$$
##### (8)
[TeX:] $$\text { Rate }_{F_{x}}^{s}=\frac{1}{T_{\text {slot}}} * \log \operatorname{En}_{F x}^{s}$$
##### (9)
[TeX:] $$R a t e_{F_{y}}^{r}=\frac{1}{T_{s l o t}} * \log E n_{F_{y}}^{r}$$
##### 3.5 The Cloud System
In the proposed framework, the core services (such as historical data analytics, storage management, authentication, authorization services, and core medical resource management infrastructure) are processed by the cloud computing layer. Additionally, large scale data mining requiring heavy computation, such as MapReduce and Apache Spark, are also implemented by the cloud system. The cloud system relies on a continuous back-end computation to keep within sight of IoT wearable medical devices and update the fog nodes.
##### 3.6 Medical Resource Management Layer
The core of any healthcare analytics system is the efficiency of its classifier. As the collected data may be big, unbounded, or unbalanced, classification becomes increasingly complex. Furthermore, the data distribution may be unbalanced resulting in one class containing more samples compared to other classes. The most vital part of the classifier model implementation is the feature or attribute selection. Recently, deep learning algorithms such as AlexNet, LeNet, multilayer perceptron (MLP) and recurrent long short-term memory (LSTM) have the ability to deal with high dimensional data and outperform many other classic techniques in terms of efficiency, precision, and accuracy.
Apache Spark is a powerful clustering big data framework based on Hadoop developed at AMPLAB, UC Berkeley in 2010 [4]. It is distinguished by its high reliability, consistency, speed, and fault tolerance. As shown in Fig. 1, the fundamental components in Apache Spark contain four main libraries: structured query language (SQL), streaming, Spark MLlib, and GraphX [9]. In order to generate either a recommendation or specific disease diagnosis, SparkML relies on knowledge bases such as the Web Ontology Language (OWL2) and Open Biomedical and Biological Ontologies (OBO) to generate rules, ontologies, and semantic annotation. Real-time stream computation is done by Apache Spark streaming while Spark SQL deals with relational queries on the different database systems. The GraphX library provides distributed processing to manage the graph. Spark MLlib is the most important component as it contains more than 55 expandable analytical machine-learning methods to provide parallelization [8]. Its components have been developed by many researchers to benefit from big data analytics worldwide. A variety of machine-learning approaches are embedded in Apache Spark MLlib, such as classification, regression, and filtering.
##### 3.7 Healthcare Security Layer
The healthcare security layer plays a vital role in confirming that admission privileges are accurate using pre-defined policies. The cloud system data are protected with an IoT broker that either accepts or rejects access. Registered and authenticated requests are subsequently mapped to the next layer. Data security and privacy are ensured with anomaly detection and privacy preserving data mining [5]. The IoT data received from wearable devices are vulnerable to many attacks. Therefore, a privacy protection mechanism must be employed to handle such attacks and prevent data alteration or removal. These mechanisms are not considered in this paper. To prevent malicious attacks, viruses, and any other issues that might affect user trust, the proposed framework includes physical connection security, communi¬cation protection, information flow protection, cryptographic protection, authentication, healthcare device security, healthcare device monitoring, and threat analysis modules.
The healthcare device security module ensures wearable device integrity by confirming the settings needed to perform its specified functions. These settings control different security policies of the devices and, if needed, update the structure for known vulnerabilities. The healthcare device monitoring module keeps IoT wearable devices continuously monitored. The monitoring process is done through integrity checks, service denial activities, and malicious usage detection. Physical connection layer attacks are handled by the security of physical connection module. The communication protection module with the aid of the information flow protection module encrypts the data transferred between devices, fog nodes, and the cloud system using standardization protocols and boundary protection technologies. The cryptographic protection module controls updates for all to other modules within the framework Moreover, it manages security policies for all communication lines such as password-protected commu¬nication settings, and firewall configuration. The threat analysis module analyzes abnormal behavior by searching for malicious patterns that may cause harmful system crashes. Abnormal behavior is discovered by the system after learning normal behavior and building a rule-based set with specific abnormal events.
Finally, the overall feedback of the healthcare system is oriented towards one user through the personalized notification/decision layer. The system stakeholders are patients, doctors, clinics, data scientists, paramedics, pharmacists, and decision makers.
## 4. Discussion
To study the validity of the proposed framework , table 1 presents a comparison between four related frameworks and our proposed in terms of base platform, streaming type, streaming primitive, streaming source, and transmission delay. As noticed from Table 1, both [7,8] lacks real-time streaming (i.e., they only batched) while the transmission delay is high (few seconds) in both [5,7] and medium (sub seconds) in [4]. The proposed framework outperform the related frameworks in terms of latency due to dependency a delay minimizing offloading policy. It utilizes a fog layer which deliver the heavy data load to the cloud system that handles the computationally intensive application processing.
Table 1.
The proposed framework compared to four related frameworks
Base platform Streaming type Streaming primitive Streaming source Transmission delay
Al-Khafajiy et al. [8] Hadoop batch Key value HDFS N/A
Mishu [7] Hadoop batch Key value HDFS High
Aktas et al. [5] Opnet Simulator N/A N/A N/A High
Khan et al. [4] Apache Spark Batch/real time DStream HDFS Medium
Proposed framework Apache Spark Batch/real time DStream HDFS Low
Moreover, although most recent health analytics frameworks are based on business logic tier (such as Apache Spark or Hadoop) and data access (such as Cassandra, spouts, or, HDFS), our proposed framework go further by offering some more powerful features. Compared to other related frameworks, mentioned in Table 2, the proposed framework achieve a precedence in terms of validity, sustainability, separation of layers and fault tolerance. These frameworks are limited to images alone, not scalable and did not provide confidentiality and data integrity. Reliability, compliance, integrity, and confidentiality are important features in order to prohibit tampering, denial of service attacks, and spoofing. However, most related frameworks lacks most of these features due to either inability to remember a PIN to access, complexity in key management, or late validation timing.
Table 2.
The proposed framework compared to four related frameworks in terms of 8 features
Validity Sustainability Separation of layers Fault tolerance Reliability Compliance Data integrity Confidentiality
Al-Khafajiy et al. [8]
Mishu [7]
Aktas et al. [5]
Khan et al. [4]
Proposed framework
## 5. Conclusion
In this paper, we presented a framework for healthcare IoT big data analytics that is based on both fog and cloud computing. Additionally, it utilizes Apache Spark components to classify medical data using different machine-learning algorithms, and to make timely decisions. A detailed analysis and illustration of the proposed framework is presented. In general, the proposed framework could alert patients in real-time when a problem occurs, allowing them to take action when necessary. Analytics conducted at the fog side help to manage extremely large medical IoT data streams from different sources. In the future, a detailed analysis of the proposed framework will be conducted, with a focus on processing time, feature extraction, and fog computing offloading challenges.
## Acknowledgement
We are indebted to the Deanship of Scientific Research at Jouf University for funding this work through General Research Project (No. 40/201).
## Biography
##### Hamoud Alshammari
https://orcid.org/0000-0001-6843-3732
He is an Assistance Professor and the computer sciences and Information head department at Algurayyat College for Arts and Sciences at Aljouf University. He holds a Ph.D. in a Computer Sciences and Engineering from the University of Bridgeport, CT-USA 2016. He was the head department and computer center labs at Aljouf Technology College, then he worked as the customer relationship head department at Saudi Electricity Company at Aljouf office. He worked as a teaching assistance for graduate level at the University of Bridgeport. He is a member in Upsilon Pi Epsilon Honor Society, which recognize talent in computer science field, USA. He had attended 1-year data scientist course that is proposed by John Hopkins University, and he is a certified with many tools and skills by this course. His research area includes working on bigdata collection and analysis, Hadoop developing environment, NoSQL databases, IoT and wireless sensors systems. Also, he is working on health information systems data analysis.
## Biography
##### Sameh Abd El-Ghany
https://orcid.org/0000-0002-5903-3048
He received B.S. degree in 2003 from information systems department, Mansoura University, Egypt, and the M.Sc. degree in 2009 from Mansoura University, Egypt, entitled thesis "An approach for image retrieval based on mobile agent". He received Ph.D. degree from faculty of computer science and information, Mansoura University, Egypt. His research interests include information retrieval, image processing, sentiment analysis and semantic web. He is currently an Assistant Professor at the Department of Information Systems, College of Information and Computer Sciences, Jouf University, Saudi Arabia.
## Biography
##### Abdulaziz Shehab
https://orcid.org/0000-0001-8610-7172
He received B.Sc. degree in information systems from College of Computer Science and Information Systems, Mansoura University, Egypt, in 2004. In 2009, he obtained his M.Sc. degree in information systems department (thesis entitled "Automated essay grading system based on intelligent text mining techniques"). In 2015, he obtained his Ph.D. degree in information systems department (dissertation entitled "Efficient schemes for internet-based video delivery"). In 2015, He start working as a manager of e-courses production center, Mansoura University. Currently, he is working as an assistant professor at Jouf University, Saudi Arabia. His research interests includes text mining, neural networks, natural language processing, computer networks, multimedia communications, biometrics systems, decision support systems (DSS), Internet of Things (IoT), and related topics.
## References
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• 2 D. Dias, J. Paulo Silva Cunha, "Wearable health devices: vital sign monitoring, systems and technologies," Sensors, vol. 18, no. 8, 2018.custom:[[[-]]]
• 3 J. Xie, F. R. Yu, T. Huang, R. Xie, J. Liu, C. Wang, Y. Liu, "A survey of machine learning techniques applied to software defined networking (SDN): research issues and challenges," IEEE Communications Surveys & Tutorials, vol. 21, no. 1, pp. 393-430, 2018.custom:[[[-]]]
• 4 M. A. Khan, M. Karim, Y. Kim, "A two-stage big data analytics framework with real world applications using spark machine learning and long short-term memory network," Symmetry, vol. 10, no. 10, 2018.doi:[[[10.3390/sym10100485]]]
• 5 F. Aktas, C. Ceken, Y. E. Erdemli, "IoT-based healthcare framework for biomedical applications," Journal of Medical and Biological Engineering, vol. 38, no. 6, pp. 966-979, 2018.custom:[[[-]]]
• 6 Y. Shen, C. Wu, C. Liu, Y. Wu, N. Xiong, "Oriented feature selection SVM applied to cancer rediction in precision medicine," IEEE Access, vol. 6, pp. 48510-48521, 2018.custom:[[[-]]]
• 7 M. M. Mishu, "A patient oriented framework using big data & c-means clustering for biomedical engineering applications," in Proceedings of 2019 International Conference on Robotics, Electrical and Signal Processing Techniques (ICREST), Dhaka, Bangladesh, 2019;pp. 113-115. custom:[[[-]]]
• 8 M. Al-Khafajiy, L. Webster, T. Baker, A. Waraich, "Towards fog driven IoT healthcare: challenges and framework of fog computing in healthcare," in Proceedings of the 2nd International Conference on Future Networks and Distributed Systems, Amman, Jordan, 2018;pp. 1-7. custom:[[[-]]]
• 9 T. Alhussain, "Medical big data analysis using big data tools and methods," Journal of Medical Imaging and Health Informatics, vol. 8, no. 4, pp. 793-795, 2018.custom:[[[-]]]
• 10 A. Yousefpour, G. Ishigaki, R. Gour, J. P. Jue, "On reducing IoT service delay via fog offloading," IEEE Internet of Things Journal, vol. 5, no. 2, pp. 998-1010, 2018.doi:[[[10.1109/JIOT.2017.2788802]]]
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2021-09-16 19:42:37
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https://cs.stackexchange.com/questions/101326/numbers-lying-between-single-and-double-precision
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# Numbers lying between single and double precision
The IEEE floating point number format is defined as
$$s\underbrace{c_1\dots c_m}_\text{exponent}\underbrace{f_1\dots f_n}_\text{fraction}\text{ (*)}$$
with $$s, c_i, f_j$$ being either $$1$$ or $$0$$. The corresponding decimal representations are as follows: $$c = \sum\limits_{i=1}^m c_i 2^i 2^{m-i}$$ $$f=\sum\limits_{i=1}^n f_i 2^{-i}$$
Let $$\xi$$ be the corresponding decimal representation of (*). Then $$\xi = (-1)^s 2^{c-(2^{m-1}-1)}(1+f)$$
In the case of single precision, $$m=8$$ and $$n=23$$ and in double precision these are $$m=11$$ and $$n=52$$.
I want to find how many double precision floating point numbers there are between any two single precision floating point numbers.
Here's my approach to solving this:
Let $$x_1 := 2^{c_{sp}-(2^7-1)}(1+f_{sp})$$, $$x_2=2^{c_{dp}-(2^{10}-1)}(1+f_{dp})$$, where $$c_{sp}=(11111110)_2=254$$ and $$c_{dp}=(00011111110)_2$$ are corresponding single and double precision representations (here I'm taking the largest exponent for single precision and the corresponding exponent in double precision).
Now, let $$d := |x_{2,sp}-x_{1,sp}|$$ be the difference between two adjacent floating point numbers, where $$x_{1,sp}:=2^{c_{sp}-(2^7-1)}(1-f_{1, sp})$$ and $$x_{2,sp}:=2^{c_{sp}-(2^7-1)}(1-f_{2, sp})$$ and $$f_{2,sp}=(0.\underbrace{11\dots1}_\text{23 times})_2$$, $$f_{1,sp}=f_{2,sp}-\epsilon=(0.11\dots10)_2$$. The corresponding double precision representations are $$f_{2,dp}=0.\underbrace{11\dots1}_\text{23 times}\underbrace{0\dots 0}_\text{52-23 times}$$, $$f_{1,dp}=0.\underbrace{11\dots1}_\text{22 times}\underbrace{0\dots 0}_\text{52-22 times}$$.
Then, clearly, the double precision representation has 29 additional places after the binary (fractional) point. Which means that there are $$2^{29}-1$$, that is $$n_{dp}-n_{sp}$$, numbers in double precision between any two single precision numbers.
Do you think this is correct?
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2019-08-23 18:41:54
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http://www.ida.liu.se/divisions/aiics/pubs/?abstract=true
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# AIICS Publications: All Publications
Hide abstracts BibTeX entries 2018 [568] Fredrik Heintz and Linda Mannila. 2018. Computational Thinking for All - An Experience Report on Scaling up Teaching Computational Thinking to All Students in a Major City in Sweden. In Proceedings of the 49th ACM Technical Symposium on Computer Science Education (SIGCSE). 2017 [567] Piotr Rudol and Patrick Doherty. 2017. Bridging Reactive and Control Architectural Layers for Cooperative Missions Using VTOL Platforms. In Henry Selvaraj, editor, Proceedings of the 25thInternational Conference on Systems Engineering (ICSENG), pages 21–32. ISBN: 978-1-5386-0609-4. Note: Funding Agencies|Swedish Research Council (VR) Linnaeus Center CADICS; ELLIIT network organization for Information and Communication Technology; Swedish Foundation for Strategic Research [RIT 15-0097] In this paper we address the issue of connect- ing abstract task definitions at a mission level with control functionalities for the purpose of performing autonomous robotic missions using multiple heterogenous platforms. The heterogeneity is handled by the use of a common vocabulary which consists of parametrized tasks such as fly-to, take- off, scan-area, or land. Each of the platforms participating in a mission supports a subset of the tasks by providing their platform-specific implementations. This paper presents a detailed description of an approach for implementing such platform-specific tasks. It is achieved using a flight-command based interface with setpoint generation abstraction layer for vertical take-off and landing platforms. We show that by using this highly expressive and easily parametrizable way of specifying and executing flight behaviors it is straightforward to implement a wide range of tasks. We describe the method in the context of a previously described robotics architecture which includes mission delegation and execution system based on a task specification language. We present results of an experimental flight using the proposed method. [566] Fredrik Prntare, Ingemar Ragnemalm and Fredrik Heintz. 2017. An Algorithm for Simultaneous Coalition Structure Generation and Task Assignment. In Proceedings ofthe 20th International Conference on Principles and Practice of Multi-Agent Systems (PRIMA). In series: Lecture notes in artificial intelligence #10621. Springer. ISBN: 978-3-319-69130-5. Groups of agents in multi-agent systems may have to cooperate to solve tasks efficiently, and coordinating such groups is an important problem in the field of artificial intelligence. In this paper, we consider the problem of forming disjoint coalitions and assigning them to independent tasks simultaneously, and present an anytime algorithm that efficiently solves the simultaneous coalition structure generation and task assignment problem. This NP-complete combinatorial optimization problem has many real-world applications, including forming cross-functional teams aimed at solving tasks. To evaluate the algorithm's performance, we extend established methods for synthetic problem set generation, and benchmark the algorithm using randomized data sets of varying distribution and complexity. Our results show that the presented algorithm efficiently finds optimal solutions, and generates high quality solutions when interrupted prior to finishing an exhaustive search. Additionally, we apply the algorithm to solve the problem of assigning agents to regions in a commercial computer-based strategy game, and empirically show that our algorithm can significantly improve the coordination and computational efficiency of agents in a real-time multi-agent system. [565] Fredrik Heintz, Linda Mannila, Lars-ke Nordn, Parnes Peter and Regnell Bjrn. 2017. Introducing Programming and DigitalCompetence in Swedish K-9 Education. In Proceeding of the 10th International Conference on Informatics in Schools: Situation, Evolution, and Perspective (ISSEP). The role of computer science and IT in Swedish schools hasvaried throughout the years. In fall 2014, the Swedish government gavethe National Agency for Education (Skolverket) the task of preparing aproposal for K-9 education on how to better address the competencesrequired in a digitalized society. In June 2016, Skolverket handed overa proposal introducing digital competence and programming as interdisciplinarytraits, also providing explicit formulations in subjects such asmathematics (programming, algorithms and problem-solving), technology(controlling physical artifacts) and social sciences (fostering awareand critical citizens in a digital society). In March 2017, the governmentapproved the new curriculum, which needs to be implemented by fall 2018 at the latest. We present the new K-9 curriculum and put it ina historical context. We also describe and analyze the process of developingthe revised curriculum, and discuss some initiatives for how toimplement the changes. [564] Mariusz Wzorek, Cyrille Berger and Patrick Doherty. 2017. A Framework for Safe Navigation of Unmanned Aerial Vehicles in Unknown Environments. In 25th International Conference on Systems Engineering. ISBN: 978-1-5386-0609-4. Note: Funding Agencies|Swedish Research Council (VR) Linnaeus Center CADICS; ELLIIT network organization for Information and Communication Technology; Swedish Foundation for Strategic Research [RIT 15-0097] This paper presents a software framework which combines reactive collision avoidance control approach with path planning techniques for the purpose of safe navigation of multiple Unmanned Aerial Vehicles (UAVs) operating in unknown environments. The system proposed leverages advantages of using a fast local sense-and-react type control which guarantees real-time execution with computationally demanding path planning algorithms which generate globally optimal plans. A number of probabilistic path planning algorithms based on Probabilistic Roadmaps and Rapidly- Exploring Random Trees have been integrated. Additionally, the system uses a reactive controller based on Optimal Reciprocal Collision Avoidance (ORCA) for path execution and fast sense-and-avoid behavior. During the mission execution a 3D map representation of the environment is build incrementally and used for path planning. A prototype implementation on a small scale quad-rotor platform has been developed. The UAV used in the experiments was equipped with a structured-light depth sensor to obtain information about the environment in form of occupancy grid map. The system has been tested in a number of simulated missions as well as in real flights and the results of the evaluations are presented. [563] Daniel de Leng. 2017. Spatio-Temporal Stream Reasoning with Adaptive State Stream Generation. Licentiate Thesis. In series: Linkping Studies in Science and Technology. Thesis #1783. Linkping University Electronic Press. 133 pages. ISBN: 9789176854761. DOI: 10.3384/lic.diva-138645. Note: The series name Linköping Studies in Science and Technology Licentiate Thesis is inocorrect. The correct series name is Linköping Studies in Science and Technology Thesis. cover: http://liu.diva-portal.org/smash/get/div... preview image: http://liu.diva-portal.org/smash/get/div... A lot of today's data is generated incrementally over time by a large variety of producers. This data ranges from quantitative sensor observations produced by robot systems to complex unstructured human-generated texts on social media. With data being so abundant, making sense of these streams of data through reasoning is challenging. Reasoning over streams is particularly relevant for autonomous robotic systems that operate in a physical environment. They commonly observe this environment through incremental observations, gradually refining information about their surroundings. This makes robust management of streaming data and its refinement an important problem.Many contemporary approaches to stream reasoning focus on the issue of querying data streams in order to generate higher-level information by relying on well-known database approaches. Other approaches apply logic-based reasoning techniques, which rarely consider the provenance of their symbolic interpretations. In this thesis, we integrate techniques for logic-based spatio-temporal stream reasoning with the adaptive generation of the state streams needed to do the reasoning over. This combination deals with both the challenge of reasoning over streaming data and the problem of robustly managing streaming data and its refinement.The main contributions of this thesis are (1) a logic-based spatio-temporal reasoning technique that combines temporal reasoning with qualitative spatial reasoning; (2) an adaptive reconfiguration procedure for generating and maintaining a data stream required to perform spatio-temporal stream reasoning over; and (3) integration of these two techniques into a stream reasoning framework. The proposed spatio-temporal stream reasoning technique is able to reason with intertemporal spatial relations by leveraging landmarks. Adaptive state stream generation allows the framework to adapt in situations in which the set of available streaming resources changes. Management of streaming resources is formalised in the DyKnow model, which introduces a configuration life-cycle to adaptively generate state streams. The DyKnow-ROS stream reasoning framework is a concrete realisation of this model that extends the Robot Operating System (ROS). DyKnow-ROS has been deployed on the SoftBank Robotics NAO platform to demonstrate the system's capabilities in the context of a case study on run-time adaptive reconfiguration. The results show that the proposed system – by combining reasoning over and reasoning about streams – can robustly perform spatio-temporal stream reasoning, even when the availability of streaming resources changes. [562] Fredrik Heintz and Fredrik Lfgren. 2017. Linkping Humanoids: Application RoboCup 2017 Standard Platform League. In , pages 1–2. fulltext:preprint: http://liu.diva-portal.org/smash/get/div... movie: http://liu.diva-portal.org/smash/get/div... This is the application for the RoboCup 2017 Standard Platform League from the Link¨oping Humanoids teamLinköping Humanoids participated in both RoboCup 2015 and 2016 with the intention of incrementally developing a good team by learning as much as possible. We significantly improved from 2015 to 2016, even though we still didn’t perform very well. Our main challenge is that we are building our software from the ground up using the Robot Operating System (ROS) as the integration and development infrastructure. When the system became overloaded, the ROS infrastructure became very unpredictable. This made it very hard to debug during the contest, so we basically had to remove things until the load was constantly low. Our top priority has since been to make the system stable and more resource efficient. This will take us to the next level.From the start we have been clear that our goal is to have a competitive team by 2017 since we are developing our own software from scratch we are very well aware that we needed time to build up the competence and the software infrastructure. We believe we are making good progress towards this goal. The team of about 10 students has been very actively working during the fall with weekly workshops and bi-weekly one day hackathons. [561] Olov Andersson. 2017. Methods for Scalable and Safe Robot Learning. Licentiate Thesis. In series: Linkping Studies in Science and Technology. Thesis #1780. Linkping University Electronic Press. 37 pages. ISBN: 978-91-7685-490-7. DOI: 10.3384/lic.diva-138398. Fulltext: https://doi.org/10.3384/lic.diva-138398 cover: http://liu.diva-portal.org/smash/get/div... preview image: http://liu.diva-portal.org/smash/get/div... Robots are increasingly expected to go beyond controlled environments in laboratories and factories, to enter real-world public spaces and homes. However, robot behavior is still usually engineered for narrowly defined scenarios. To manually encode robot behavior that works within complex real world environments, such as busy work places or cluttered homes, can be a daunting task. In addition, such robots may require a high degree of autonomy to be practical, which imposes stringent requirements on safety and robustness. \setlength{\parindent}{2em}\setlength{\parskip}{0em}The aim of this thesis is to examine methods for automatically learning safe robot behavior, lowering the costs of synthesizing behavior for complex real-world situations. To avoid task-specific assumptions, we approach this from a data-driven machine learning perspective. The strength of machine learning is its generality, given sufficient data it can learn to approximate any task. However, being embodied agents in the real-world, robots pose a number of difficulties for machine learning. These include real-time requirements with limited computational resources, the cost and effort of operating and collecting data with real robots, as well as safety issues for both the robot and human bystanders.While machine learning is general by nature, overcoming the difficulties with real-world robots outlined above remains a challenge. In this thesis we look for a middle ground on robot learning, leveraging the strengths of both data-driven machine learning, as well as engineering techniques from robotics and control. This includes combing data-driven world models with fast techniques for planning motions under safety constraints, using machine learning to generalize such techniques to problems with high uncertainty, as well as using machine learning to find computationally efficient approximations for use on small embedded systems.We demonstrate such behavior synthesis techniques with real robots, solving a class of difficult dynamic collision avoidance problems under uncertainty, such as induced by the presence of humans without prior coordination. Initially using online planning offloaded to a desktop CPU, and ultimately as a deep neural network policy embedded on board a 7 quadcopter. [560] Mariusz Wzorek, Piotr Rudol, Gianpaolo Conte and Patrick Doherty. 2017. LinkBoard: Advanced Flight Control System for Micro Unmanned Aerial Vehicles. In 2017 2ND INTERNATIONAL CONFERENCE ON CONTROL AND ROBOTICS ENGINEERING (ICCRE2017). IEEE. ISBN: 978-1-5090-3774-2. DOI: 10.1109/ICCRE.2017.7935051. Note: Funding Agencies|Swedish Research Council (VR) Linnaeus Center CADICS; ELLIIT network organization for Information and Communication Technology; Swedish Foundation for Strategic Research [RIT 15-0097] This paper presents the design and development of the LinkBoard, an advanced flight control system for micro Unmanned Aerial Vehicles (UAVs). Both hardware and software architectures are presented. The LinkBoard includes four processing units and a full inertial measurement unit. In the basic configuration, the software architecture includes a fully configurable set of control modes and sensor fusion algorithms for autonomous UAV operation. The system proposed allows for easy integration with new platforms, additional external sensors and a flexibility to trade off computational power, weight and power consumption. Due to the available onboard computational power, it has been used for computationally demanding applications such as the implementation of an autonomous indoor vision-based navigation system with all computations performed onboard. The autopilot has been manufactured and deployed on multiple UAVs. Examples of UAV systems built with the LinkBoard and their applications are presented, as well as an in-flight experimental performance evaluation of a newly developed attitude estimation filter. [559] Daniel de Leng and Fredrik Heintz. 2017. Towards Adaptive Semantic Subscriptions for Stream Reasoning in the Robot Operating System. In Proceedings of the 2017 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), pages 5445–5452. IEEE conference proceedings. ISBN: 9781538626818. Modern robotic systems often consist of a growing set of information-producing components that need to be appropriately connected for the system to function properly. This is commonly done manually or through relatively simple scripts by specifying explicitly which components to connect. However, this process is cumbersome and error-prone, does not scale well as more components are introduced, and lacks flexibility and robustness at run-time. This paper presents an algorithm for setting up and maintaining implicit subscriptions to information through its semantics rather than its source, which we call semantic subscriptions. The proposed algorithm automatically reconfigures the system when necessary in response to changes at run-time, making the semantic subscriptions adaptive to changing circumstances. To illustrate the effectiveness of adaptive semantic subscriptions, we present a case study with two SoftBank Robotics NAO robots for handling the cases when a component stops working and when new components, in this case a second robot, become available. The solution has been implemented as part of a stream reasoning framework integrated with the Robot Operating System (ROS). [558] Daniel Artchounin. 2017. Tuning of machine learning algorithms for automatic bug assignment. Student Thesis. 135 pages. ISRN: LIU-IDA/LITH-EX-A--17/022--SE. In software development projects, bug triage consists mainly of assigning bug reports to software developers or teams (depending on the project). The partial or total automation of this task would have a positive economic impact on many software projects. This thesis introduces a systematic four-step method to find some of the best configurations of several machine learning algorithms intending to solve the automatic bug assignment problem. These four steps are respectively used to select a combination of pre-processing techniques, a bug report representation, a potential feature selection technique and to tune several classifiers. The aforementioned method has been applied on three software projects: 66 066 bug reports of a proprietary project, 24 450 bug reports of Eclipse JDT and 30 358 bug reports of Mozilla Firefox. 619 configurations have been applied and compared on each of these three projects. In production, using the approach introduced in this work on the bug reports of the proprietary project would have increased the accuracy by up to 16.64 percentage points. [557] Tova Linder and Ola Jigin. 2017. Organ Detection and Localization in Radiological Image Volumes. Student Thesis. 88 pages. ISRN: LIU-IDA/LITH-EX-A--17/024--SE. Using Convolutional Neural Networks for classification of images and for localization and detection of objects in images is becoming increasingly popular. Within radiology a huge amount of image data is produced and meta data containing information of what the images depict is currently added manually by a radiologist. To aid in streamlining physician’s workflow this study has investigated the possibility to use Convolutional Neural Networks (CNNs) that are pre-trained on natural images to automatically detect the presence and location of multiple organs and body-parts in medical CT images. The results show promise for multiclass classification with an average precision 89.41% and average recall 86.40%. This also confirms that a CNN that is pre-trained on natural images can be succesfully transferred to solve a different task. It was also found that adding additional data to the dataset does not necessarily result in increased precision and recall or decreased error rate. It is rather the type of data and used preprocessing techniques that matter. [556] Elena Moral Lpez. 2017. Muting pattern strategy for positioning in cellular networks. Student Thesis. 65 pages. ISRN: LIU-IDA/LITH-EX-A--17/018--SE. Location Based Services (LBS) calculate the position of the user for different purposes like advertising and navigation. Most importantly, these services are also used to help emergency services by calculating the position of the person that places the emergency phone call. This has introduced a number of requirements on the accuracy of the measurements of the position. Observed Time Difference of Arrival (OTDOA) is the method used to estimate the position of the user due to its high accuracy. Nevertheless, this method relies on the correct reception of so called positioning signals, and therefore the calculations can suffer from errors due to interference between the signals. To lower the probability of interference, muting patterns can be used. These methods can selectively mute certain signals to increase the signal to interference and noise ratio (SINR) of others and therefore the number of signals detected. In this thesis, a simulation environment for the comparison of the different muting patterns has been developed. The already existing muting patterns have been simulated and compared in terms of number of detected nodes and SINR values achieved. A new muting pattern has been proposed and compared to the others. The results obtained have been presented and an initial conclusion on which of the muting patterns offers the best performance has been drawn. [555] Petra hlin. 2017. Prioritizing Tests with Spotify?s Test & Build Data using History-based, Modification-based & Machine Learning Approaches. Student Thesis. 43 pages. ISRN: LIU-IDA/LITH-EX-A--2017/021--SE. This thesis intends to determine the extent to which machine learning can be used to solve the regression test prioritization (RTP) problem. RTP is used to order tests with respect to probability of failure. This will optimize for a fast failure, which is desirable if a test suite takes a long time to run or uses a significant amount of computational resources. A common machine learning task is to predict probabilities; this makes RTP an interesting application of machine learning. A supervised learning method is investigated to train a model to predict probabilities of failure, given a test case and a code change. The features investigated are chosen based on previous research of history- based and modification-based RTP. The main motivation for looking at these research areas is that they resemble the data provided by Spotify. The result of the report shows that it is possible to improve how tests run with RTP using machine learning. Nevertheless, a much simpler history- based approach is the best performing approach. It is looking at the history of test results, the more failures recorded for the test case over time, the higher priority it gets. Less is sometimes more. [554] Joakim Gylling. 2017. Transition-Based Dependency Parsing with Neural Networks. Student Thesis. 10 pages. ISRN: LIU-IDA/LITH-EX-G--17/011--SE. Dependency parsing is important in contemporary speech and language processing systems. Current dependency parsers typically use the multi-class perceptron machine learning component, which classifies based on millions of sparse indicator features, making developing and maintaining these systems expensive and error-prone. This thesis aims to explore whether replacing the multi-class perceptron component with an artificial neural network component can alleviate this problem without hurting performance, in terms of accuracy and efficiency. A simple transition-based dependency parser using the artificial neural network (ANN) as the classifier is written in Python3 and the same program with the classifier replaced by a multi-class perceptron component is used as a baseline. The results show that the ANN dependency parser provides slightly better unlabeled attachment score with only the most basic atomic features, eliminating the need for complex feature engineering. However, it is about three times slower and the training time required for the ANN is significantly longer. [553] Maximilian Bragazzi Ihrn and Henrik Ingbrant Bjrs. 2017. Visualizing atmospheric data on a mobile platform. Student Thesis. 10 pages. ISRN: LIU-IDA/LITH-EX-G--17/010--SE. Weather data is important for almost everyone today. Thedaily weather report, home thermometers, and a lot of otherthings affect our every day life. In order to develop betterand more efficient equipment, tools and algorithms, thepeople working with this data need to be able to access it inan easily accessible and easy to read format. In thisresearch, methods of visualizing data on mobile platformsare evaluated based on what researchers in the field wants,since their respective fields might want to use very specificvisualizations. The implementability of these visualizationsare then evaluated, based on the implementations madethroughout this paper. The results show that the researchersknow what they want, and that what they want isimplementable on mobile platforms given some limitationscaused by performance. [552] Fredrik Jonsn and Alexander Stolpe. 2017. The feasibility and practicality of a generic social media library. Student Thesis. ISRN: LIU-IDA/LITH-EX-G--17/009--SE. [551] Olov Andersson, Mariusz Wzorek and Patrick Doherty. 2017. Deep Learning Quadcopter Control via Risk-Aware Active Learning. In Satinder Singh and Shaul Markovitch, editors, Proceedings of The Thirty-first AAAI Conference on Artificial Intelligence (AAAI), pages 3812–3818. In series: Proceedings of the AAAI Conference on Artificial Intelligence #5. AAAI Press. ISBN: 978-1-57735-784-1. Modern optimization-based approaches to control increasingly allow automatic generation of complex behavior from only a model and an objective. Recent years has seen growing interest in fast solvers to also allow real-time operation on robots, but the computational cost of such trajectory optimization remains prohibitive for many applications. In this paper we examine a novel deep neural network approximation and validate it on a safe navigation problem with a real nano-quadcopter. As the risk of costly failures is a major concern with real robots, we propose a risk-aware resampling technique. Contrary to prior work this active learning approach is easy to use with existing solvers for trajectory optimization, as well as deep learning. We demonstrate the efficacy of the approach on a difficult collision avoidance problem with non-cooperative moving obstacles. Our findings indicate that the resulting neural network approximations are least 50 times faster than the trajectory optimizer while still satisfying the safety requirements. We demonstrate the potential of the approach by implementing a synthesized deep neural network policy on the nano-quadcopter microcontroller. [550] Oleg Burdakov, Jonas Kvarnstrm and Patrick Doherty. 2017. Optimal scheduling for replacing perimeter guarding unmanned aerial vehicles. Annals of Operations Research, 249(1):163–174. Springer. DOI: 10.1007/s10479-016-2169-5. Guarding the perimeter of an area in order to detect potential intruders is an important task in a variety of security-related applications. This task can in many circumstances be performed by a set of camera-equipped unmanned aerial vehicles (UAVs). Such UAVs will occasionally require refueling or recharging, in which case they must temporarily be replaced by other UAVs in order to maintain complete surveillance of the perimeter. In this paper we consider the problem of scheduling such replacements. We present optimal replacement strategies and justify their optimality. 2016 [549] Fredrik Heintz and Fredrik Lfgren. 2016. Linkping Humanoids: Application RoboCup 2016 Standard Platform League. In , pages 1–2. Qualification Video for RoboCup Standard Platform League 2016: https://www.youtube.com/watch?v=Og8Azj2Y... fulltext:preprint: http://liu.diva-portal.org/smash/get/div... This is the application for the RoboCup 2016 Standard Platform League from the Linköping Humanoids team.Linköping Humanoids participated in RoboCup 2015. We didn’t do very well, but we learned a lot. When we arrived nothing worked. However, we fixed more and more of the open issues and managed to play a draw in our final game. We also participated in some of the technical challenges and scored some points. At the end of the competition we had a working team. This was both frustrating and rewarding. Analyzing the competition we have identified both what we did well and the main issues that we need to fix. One important lesson is that it takes time to develop a competitive RoboCup SPL team. Weare dedicated to improving our performance over time in order to be competitive in 2017. [548] Fredrik Lfgren. 2016. How may robots affect the labour market in the near future?. In Andreas Bergström and Karl Wennberg, editors, Machines, jobs and equality: Technological changes and labour markets in Europe, pages 105–134. The European Liberal Forum (ELF). ISBN: 9789187379369. Download the complete book: http://fores.se/wp-content/uploads/2016/... fulltext:print: http://liu.diva-portal.org/smash/get/div... This chapter discusses how different applications for robots will affect the labour market in the near future. Near future refers to the next 10-50 years. It is likely that several occupations will disappear, but new ones will also emerge. However, we claim that the net result will be negative, which means that we will have higher unemployment. These effects will not happen overnight, and not all occupations will be affected. But, this will happen for a sufficient amount of the population for it to become a problem for society.The observations made in this chapter are not from the point of view of a social scientist, but that of a roboticist. The observations are taken together with readings of scientific literature on automation. I do not claim to have answers to the economic and social scientific problems thrown up, but to raise a set of critical questions for the reader.All the examples in this chapter are real technologies that exist, not just in science-fiction or future technology. However, most of the examples are still in their research stage and are either not available for the general public, or still very expensive.No one can predict the future in detail, but this chapter tries to provide a scenario of the future of different kinds of occupations through the perspective of the field of robotics. I have been developing robots for 15 years and will use some examples that I have constructed, but also examples from other roboticists. The chapter does not discuss the risks of automation for all occupations, but instead focuses on blue-collar workers, such as machine operators, the transportation sector with the advent of driverless cars, white-collar workers in offices, skilled professions in the legal and medical spheres, and creative workers. [547] Gustav Hger, Goutam Bhat, Martin Danelljan, Fahad Shahbaz Khan, Michael Felsberg, Piotr Rudol and Patrick Doherty. 2016. Combining Visual Tracking and Person Detection for Long Term Tracking on a UAV. In Proceedings of the 12th International Symposium on Advances in Visual Computing. ISBN: 978-3-319-50834-4, 978-3-319-50835-1. DOI: 10.1007/978-3-319-50835-1_50. Visual object tracking performance has improved significantly in recent years. Most trackers are based on either of two paradigms: online learning of an appearance model or the use of a pre-trained object detector. Methods based on online learning provide high accuracy, but are prone to model drift. The model drift occurs when the tracker fails to correctly estimate the tracked object’s position. Methods based on a detector on the other hand typically have good long-term robustness, but reduced accuracy compared to online methods.Despite the complementarity of the aforementioned approaches, the problem of fusing them into a single framework is largely unexplored. In this paper, we propose a novel fusion between an online tracker and a pre-trained detector for tracking humans from a UAV. The system operates at real-time on a UAV platform. In addition we present a novel dataset for long-term tracking in a UAV setting, that includes scenarios that are typically not well represented in standard visual tracking datasets. [546] Patrick Doherty and Andrzej Szalas. 2016. An Entailment Procedure for Kleene Answer Set Programs. In Sombattheera C., Stolzenburg F., Lin F., Nayak A., editors, Multi-disciplinary Trends in Artificial Intelligence. MIWAI 2016., pages 24–37. In series: Lecture Notes in Computer Science #10053. Springer. ISBN: 978-3-319-49396-1, 978-3-319-49397-8. DOI: 10.1007/978-3-319-49397-8_3. Classical Answer Set Programming is a widely known knowledge representation framework based on the logic programming paradigm that has been extensively studied in the past decades. Semantic theories for classical answer sets are implicitly three-valued in nature, yet with few exceptions, computing classical answer sets is based on translations into classical logic and the use of SAT solving techniques. In this paper, we introduce a variation of Kleene three-valued logic with strong connectives, R3\" role=\"presentation\">R3, and then provide a sound and complete proof procedure for R3\" role=\"presentation\">R3 based on the use of signed tableaux. We then define a restriction on the syntax of R3\" role=\"presentation\">R3 to characterize Kleene ASPs. Strongly-supported models, which are a subset of R3\" role=\"presentation\">R3 models are then defined to characterize the semantics of Kleene ASPs. A filtering technique on tableaux for R3\" role=\"presentation\">R3 is then introduced which provides a sound and complete tableau-based proof technique for Kleene ASPs. We then show a translation and semantic correspondence between Classical ASPs and Kleene ASPs, where answer sets for normal classical ASPs are equivalent to strongly-supported models. This implies that the proof technique introduced can be used for classical normal ASPs as well as Kleene ASPs. The relation between non-normal classical and Kleene ASPs is also considered. [545] Patrick Doherty, Jonas Kvarnstrm and Andrzej Szalas. 2016. Iteratively-Supported Formulas and Strongly Supported Models for Kleene Answer Set Programs. In Michael, Loizos; Kakas, Antonis, editors, Logics in Artificial Intelligence: 15th European Conference, JELIA 2016, Larnaca, Cyprus, November 9-11, 2016, Proceedings, pages 536–542. In series: Lecture Notes in Computer Science #10021. Springer Publishing Company. ISBN: 978-3-319-48757-1, 978-3-319-48758-8. DOI: 10.1007/978-3-319-48758-8_36. In this extended abstract, we discuss the use of iteratively-supported formulas (ISFs) as a basis for computing strongly-supported models for Kleene Answer Set Programs (ASPK). ASPK programs have a syntax identical to classical ASP programs. The semantics of ASPK programs is based on the use of Kleene three-valued logic and strongly-supported models. For normal ASPK programs, their strongly supported models are identical to classical answer sets using stable model semantics. For disjunctive ASPK programs, the semantics weakens the minimality assumption resulting in a classical interpretation for disjunction. We use ISFs to characterize strongly-supported models and show that they are polynomially bounded. [544] Fredrik Heintz, Linda Mannila and Tommy Frnqvist. 2016. A Review of Models for Introducing Computational Thinking, Computer Science and Computing in K-12 Education. In Proceedings of the 46th Frontiers in Education (FIE). In series: Frontiers in Education Conference #??. IEEE. ISBN: 978-1-5090-1790-4, 978-1-5090-1791-1. DOI: 10.1109/FIE.2016.7757410. Computing is becoming ever increasingly importantto our society. However, computing in primary and secondaryeducation has not been well developed. Computing has traditionallybeen primarily a university level discipline and there areno widely accepted general standards for what computing at K–12 level entails. Also, as the interest in this area is rather new,the amount of research conducted in the field is still limited. Inthis paper we review how 10 different countries have approachedintroducing computing into their K–12 education. The countriesare Australia, England, Estonia, Finland, New Zealand, Norway,Sweden, South Korea, Poland and USA.The studied countries either emphasize digital competenciestogether with programming or the broader subject of computingor computer science. Computational thinking is rarely mentionedexplicitly, but the ideas are often included in some form. Themost common model is to make it compulsory in primary schooland elective in secondary school. A few countries have made itcompulsory in both. While some countries have only introducedit in secondary school. [543] Piotr Rudol and Patrick Doherty. 2016. Bridging the mission-control gap: A flight command layer for mediating flight behaviours and continuous control. In 2016 IEEE International Symposium on Safety, Security, and Rescue Robotics (SSRR), pages 304–311. In series: 2016 IEEE INTERNATIONAL SYMPOSIUM ON SAFETY, SECURITY, AND RESCUE ROBOTICS (SSRR) #??. Institute of Electrical and Electronics Engineers (IEEE). ISBN: 9781509043491, 9781509043507. DOI: 10.1109/SSRR.2016.7784320. The use of UAVs, in particular, micro VTOL UAVs, is becoming prevalent in emergency rescue and security applications, among others. In these applications, the platforms are tightly coupled to the human users and these applications require great flexibility in the interaction between the platforms and such users. During operation, one continually switches between manual, semi-autonomous and autonomous operation, often re-parameterising, breaking in, pausing, and resuming missions. One is in continual need of modifying existing elementary actions and behaviours such as FlyTo and TrackObject, and seamlessly switching between such operations. This paper proposes a flight command and setpoint abstraction layer that serves as an interface between continuous control and higher level elementary flight actions and behaviours. Introduction of such a layer into an architecture offers a versatile and flexible means of defining flight behaviours and dynamically parameterising them in the field, in particular where human users are involved. The system proposed is implemented in prototype and the paper provides experimental validation of the use and need for such abstractions in system architectures. [542] Marcus Johansson. 2016. Online Whole-Body Control using Hierarchical Quadratic Programming: Implementation and Evaluation of the HiQP Control Framework. Student Thesis. 76 pages. ISRN: LIU-IDA/LITH-EX-A--16/056--SE. The application of local optimal control is a promising paradigm for manipulative robot motion generation.In practice this involves instantaneous formulations of convex optimization problems depending on the current joint configuration of the robot and the environment.To be effective, however, constraints have to be carefully constructed as this kind of motion generation approach has a trade-off of completeness.Local optimal solvers, which are greedy in a temporal sense, have proven to be significantly more effective computationally than classical grid-based or sampling-based planning approaches.In this thesis we investigate how a local optimal control approach, namely the task function approach, can be implemented to grant high usability, extendibility and effectivity.This has resulted in the HiQP control framework, which is compatible with ROS, written in C++.The framework supports geometric primitives to aid in task customization by the user.It is also modular as to what communication system it is being used with, and to what optimization library it uses for finding optimal controls.We have evaluated the software quality of the framework according to common quantitative methods found in the literature.We have also evaluated an approach to perform tasks using minimal jerk motion generation with promising results.The framework also provides simple translation and rotation tasks based on six rudimentary geometric primitives.Also, task definitions for specific joint position setting, and velocity limitations were implemented. [541] Mattias Tiger and Fredrik Heintz. 2016. Stream Reasoning using Temporal Logic and Predictive Probabilistic State Models. In 23nd International Symposium on Temporal Representation and Reasoning (TIME), 2016. IEEE Computer Society. Note: Presented at the 23nd International Symposium on Temporal Representation and Reasoning (TIME) at the Technical University of Denmark (DTU), Denmark, the 19th October 2016. Integrating logical and probabilistic reasoning and integrating reasoning over observations and predictions are two important challenges in AI. In this paper we propose P-MTL as an extension to Metric Temporal Logic supporting temporal logical reasoning over probabilistic and predicted states. The contributions are (1) reasoning over uncertain states at single time points, (2) reasoning over uncertain states between time points, (3) reasoning over uncertain predictions of future and past states and (4) a computational environment formalism that ground the uncertainty in observations of the physical world. Concrete robot soccer examples are given. [540] Cyrille Berger, Mariusz Wzorek, Jonas Kvarnstrm, Gianpaolo Conte, Patrick Doherty and Alexander Eriksson. 2016. Area Coverage with Heterogeneous UAVs using Scan Patterns. In 2016 IEEE International Symposium on Safety, Security, and Rescue Robotics (SSRR): proceedings. In series: 2016 IEEE INTERNATIONAL SYMPOSIUM ON SAFETY, SECURITY, AND RESCUE ROBOTICS (SSRR) #??. IEEE Robotics and Automation Society. ISBN: 978-1-5090-4349-1. DOI: 10.1109/SSRR.2016.7784325. fulltext:postprint: http://liu.diva-portal.org/smash/get/div... In this paper we consider a problem of scanningan outdoor area with a team of heterogeneous Unmanned AirVehicles (UAVs) equipped with different sensors (e.g. LIDARs).Depending on the availability of the UAV platforms and themission requirements there is a need to either minimise thetotal mission time or to maximise certain properties of thescan output, such as the point cloud density. The key challengeis to divide the scanning task among UAVs while taking intoaccount the differences in capabilities between platforms andsensors. Additionally, the system should be able to ensure thatconstraints such as limit on the flight time are not violated.We present an approach that uses an optimisation techniqueto find a solution by dividing the area between platforms,generating efficient scan trajectories and selecting flight andscanning parameters, such as velocity and flight altitude. Thismethod has been extensively tested on a large set of randomlygenerated scanning missions covering a wide range of realisticscenarios as well as in real flights. [539] Mattias Tiger and Fredrik Heintz. 2016. Stream Reasoning using Temporal Logic and Predictive Probabilistic State Models. In 23nd International Symposium on Temporal Representation and Reasoning (TIME), 2016, pages 196–205. IEEE Computer Society. ISBN: 978-1-5090-3825-1. DOI: 10.1109/TIME.2016.28. Note: Presented at the 23nd International Symposium on Temporal Representation and Reasoning (TIME) at the Technical University of Denmark (DTU), Denmark, the 19th October 2016. fulltext:postprint: http://liu.diva-portal.org/smash/get/div... Integrating logical and probabilistic reasoning and integrating reasoning over observations and predictions are two important challenges in AI. In this paper we propose P-MTL as an extension to Metric Temporal Logic supporting temporal logical reasoning over probabilistic and predicted states. The contributions are (1) reasoning over uncertain states at single time points, (2) reasoning over uncertain states between time points, (3) reasoning over uncertain predictions of future and past states and (4) a computational environment formalism that ground the uncertainty in observations of the physical world. Concrete robot soccer examples are given. [538] Jose Renato Garcia Braga, Gianpaolo Conte, Patrick Doherty, Haroldo Fraga Campos Velho and Elcio Hideiti Shiguemori. 2016. An Image Matching System for Autonomous UAV Navigation Based on Neural Network. In 14th International Conference on Control, Automation, Robotics and Vision (ICARCV 2016). In series: International Conference on Control Automation Robotics and Vision #??. ISBN: 978-1-5090-3549-6, 978-1-5090-3550-2. DOI: 10.1109/ICARCV.2016.7838775. Note: Funding agencies:This work was carried out with support from CNPq - National Counsel of Technological and Scientific Development - Brazil. This work is partially supported by the Swedish Research Council (VR) Linnaeus Center CADICS, ELLIIT, and the Swedish Foundation for Strategic Research (CUAS Project, SymbiKCloud Project). This paper proposes an image matching system using aerial images, captured in flight time, and aerial geo-referenced images to estimate the Unmanned Aerial Vehicle (UAV) position in a situation of Global Navigation Satellite System (GNSS) failure. The image matching system is based on edge detection in the aerial and geo-referenced image and posterior automatic image registration of these edge-images (position estimation of UAV). The edge detection process is performed by an Artificial Neural Network (ANN), with an optimal architecture. A comparison with Sobel and Canny edge extraction filters is also provided. The automatic image registration is obtained by a cross-correlation process. The ANN optimal architecture is set by the Multiple Particle Collision Algorithm (MPCA). The image matching system was implemented in a low cost/consumption portable computer. The image matching system has been tested on real flight-test data and encouraging results have been obtained. Results using real flight-test data will be presented. [537] Jose Renato Garcia Braga, Gianpaolo Conte, Patrick Doherty, Haroldo Fraga Campos Velho and Elcio Hideiti Shiguemori. 2016. Use of Artificial Neural Networks for Automatic Categorical Change Detection in Satellite Imagery. In Proceedings of the 4th Conference of Computational Interdisciplinary Sciences (CCIS 2016). Pan American Association of Computational Interdisciplinary. [536] Daniel de Leng and Fredrik Heintz. 2016. DyKnow: A Dynamically Reconfigurable Stream Reasoning Framework as an Extension to the Robot Operating System. In Proceedings of the Fifth IEEE International Conference on Simulation, Modeling, and Programming for Autonomous Robots (SIMPAR), pages 55–60. IEEE conference proceedings. ISBN: 978-1-5090-4616-4, 978-1-5090-4617-1. DOI: 10.1109/SIMPAR.2016.7862375. Note: Funding agencies: National Graduate School in Computer Science, Sweden (CUGS); Swedish Foundation for Strategic Research (SSF) project CUAS; Swedish Research Council (VR) Linnaeus Center CADICS; ELLIIT Excellence Center at Linkoping- Lund for Information Technology; Swedis DyKnow is a framework for stream reasoning aimed at robot applications that need to reason over a wide and varying array of sensor data for e.g. situation awareness. The framework extends the Robot Operating System (ROS). This paper presents the architecture and services behind DyKnow's run-time reconfiguration capabilities and offers an analysis of the quantitative and qualitative overhead. Run-time reconfiguration offers interesting advantages, such as fault recovery and the handling of changes to the set of computational and information resources that are available to a robot system. Reconfiguration capabilities are becoming increasingly important with the advances in areas such as the Internet of Things (IoT). We show the effectiveness of the suggested reconfiguration support by considering practical case studies alongside an empirical evaluation of the minimal overhead introduced when compared to standard ROS. [535] Mehul Bhatt, Esra Erdem, Fredrik Heintz and Michael Spranger. 2016. Cognitive robotics in JOURNAL OF EXPERIMENTAL and THEORETICAL ARTIFICIAL INTELLIGENCE, vol 28, issue 5, pp 779-780. Journal of experimental and theoretical artificial intelligence (Print), 28(5):779–780. TAYLOR & FRANCIS LTD. DOI: 10.1080/0952813X.2016.1218649. n/a [534] Serge Thill, Alberto Montebelli and Tom Ziemke. 2016. Workshop on Intention Recognition in HRI. In 2016 11TH ACM/IEEE INTERNATIONAL CONFERENCE ON HUMAN-ROBOT INTERACTION (HRI), pages 585–586. In series: ACM/IEEE International Conference on Human-Robot Interaction #??. IEEE. ISBN: 978-1-4673-8370-7. DOI: 10.1109/HRI.2016.7451868. The present workshop focuses on the topic of intention recognition in HRI. To be able to recognise intentions of other agents is a fundamental prerequisite to engage in, for instance, instrumental helping or mutual collaboration. It is a necessary aspect of natural interaction. In HRI, the problem is therefore bi-directional: not only does a robot need the ability to infer intentions of humans; humans also need to infer the intentions of the robot. From the human perspective, this inference draws both on the ability to attribute cognitive states to lifeless shapes, and the ability to understand actions of other agents through, for instance, embodied processes or internal simulations (i.e the human ability to form a theory of mind of other agents). How precisely, and to what degree these mechanisms are at work when interacting with social artificial agents remains unknown. From the robotic perspective, this lack of understanding of mechanisms underlying human intention recognition, or the capacity for theory of mind in general, is also challenging: the solution can, for instance, not simply be to make autonomous systems work \"just like\" humans by copying the biological solution and implementing some technological equivalent. It is therefore important to be clear about the theoretical framework(s) and inherent assumptions underlying technological implementations related to mutual intention. This remains very much an active research area in which further development is necessary. The core purpose of this workshop is thus to contribute to and advance the state of the art in this area. [533] Cyrille Berger, Piotr Rudol, Mariusz Wzorek and Alexander Kleiner. 2016. Evaluation of Reactive Obstacle Avoidance Algorithms for a Quadcopter. In Proceedings of the 14th International Conference on Control, Automation, Robotics and Vision 2016 (ICARCV). In series: International Conference on Control Automation Robotics and Vision #??. IEEE conference proceedings. ISBN: 9781509035496, 9781509047574, 9781509035502. DOI: 10.1109/ICARCV.2016.7838803. Note: Funding agencies:This work is partially supported by the Swedish Research Council (VR) Linnaeus Center CADICS, the ELLIIT network organization for Information and Communication Technology, and the Swedish Foundation for Strategic Research (CUAS Project, SymbiKCIoud Project). In this work we are investigating reactive avoidance techniques which can be used on board of a small quadcopter and which do not require absolute localisation. We propose a local map representation which can be updated with proprioceptive sensors. The local map is centred around the robot and uses spherical coordinates to represent a point cloud. The local map is updated using a depth sensor, the Inertial Measurement Unit and a registration algorithm. We propose an extension of the Dynamic Window Approach to compute a velocity vector based on the current local map. We propose to use an OctoMap structure to compute a 2-pass A* which provide a path which is converted to a velocity vector. Both approaches are reactive as they only make use of local information. The algorithms were evaluated in a simulator which offers a realistic environment, both in terms of control and sensors. The results obtained were also validated by running the algorithms on a real platform. [532] Alexander Kleiner, Fredrik Heintz and Satoshi Tadokoro. 2016. Editorial Material: Editorial: Special Issue on Safety, Security, and Rescue Robotics (SSRR), Part 2 in JOURNAL OF FIELD ROBOTICS, vol 33, issue 4, pp 409-410. Journal of Field Robotics, 33(4):409–410. WILEY-BLACKWELL. DOI: 10.1002/rob.21661. n/a [531] Tomas Melin. 2016. Implementation and Evaluation of a Continuous Code Inspection Platform. Student Thesis. 100 pages. ISRN: LIU-IDA/LITH-EX-A--16/047—SE. Establishing and preserving a high level of software quality is a not a trivial task, although the benefits of succeeding with this task has been proven profitable and advantageous. An approach to mitigate the decreasing quality of a project is to track metrics and certain properties of the project, in order to view the progression of the project’s properties. This approach may be carried out by introducing continuous code inspection with the application of static code analysis. However, as the initial common opinion is that these type of tools produce a too high number of false positives, there is a need to investigate what the actual case is. This is the origin for the investigation and case study performed in this paper. The case study is performed at Ida Infront AB in Linköping, Sweden and involves interviews with developers to determine the performance of the continuous inspection platform SonarQube, in addition to examine the general opinion among developers at the company. The author executes the implementation and configuration of a continuous inspection environment to analyze a partition of the company’s product and determine what rules that are appropriate to apply in the company’s context. The results from the investigation indicate the high quality and accuracy of the tool, in addition to the advantageous functionality of continuously monitoring the code to observe trends and the progression of metrics such as cyclomatic complexity and duplicated code, with the goal of preventing the constant increase of complex and duplicated code. Combining this with features such as false positive suppression, instant analysis feedback in pull requests and the possibility to break the build given specified conditions, suggests that the implemented environment is a way to mitigate software quality difficulties. [530] Patrick Doherty, Jonas Kvarnstrm, Piotr Rudol, Mariusz Wzorek, Gianpaolo Conte, Cyrille Berger, Timo Hinzmann and Thomas Stastny. 2016. A Collaborative Framework for 3D Mapping using Unmanned Aerial Vehicles. In PRIMA 2016: Principles and Practice of Multi-Agent Systems, pages 110–130. In series: Lecture Notes in Computer Science #9862. Springer Publishing Company. ISBN: 978-3-319-44831-2. DOI: 10.1007/978-3-319-44832-9_7. Note: Accepted for publication. This paper describes an overview of a generic framework for collaboration among humans and multiple heterogeneous robotic systems based on the use of a formal characterization of delegation as a speech act. The system used contains a complex set of integrated software modules that include delegation managers for each platform, a task specification language for characterizing distributed tasks, a task planner, a multi-agent scan trajectory generation and region partitioning module, and a system infrastructure used to distributively instantiate any number of robotic systems and user interfaces in a collaborative team. The application focusses on 3D reconstruction in alpine environments intended to be used by alpine rescue teams. Two complex UAV systems used in the experiments are described. A fully autonomous collaborative mission executed in the Italian Alps using the framework is also described. [529] Martin Estgren. 2016. Lightweight User Agents. Student Thesis. 36 pages. ISRN: LIU-IDA/LITH-EX-G--16/036--SE. The unit for information security and IT architecture at The Swedish Defence Research Agency (FOI) conducts work with a cyber range called CRATE (Cyber Range and Training Environment). Currently, simulation of user activity involves scripts inside the simulated network. This solution is not ideal because of the traces it leaves in the system and the general lack of standardised GUI API between different operating systems. FOI are interested in testing the use of artificial user agent located outside the virtual environment using computer vision and the virtualisation API to execute actions and extract information from the system.This paper focuses on analysing the reliability of template matching, a computer vision algorithm used to localise objects in images using already identified images of said object as templates. The analysis will evaluate both the reliability of localising objects and the algorithms ability to correctly identify if an object is present in the virtual environment.Analysis of template matching is performed by first creating a prototype of the agent's sensory system and then simulate scenarios which the agent might encounter. By simulating the environment, testing parameters can be manipulated and monitored in a reliable way. The parameters manipulated involves both the amount and type of image noise in the template and screenshot, the agent’s discrimination threshold for what constitutes a positive match, and information about the template such as template generality.This paper presents the performance and reliability of the agent in regards to what type of image noise affects the result, the amount of correctly identified objects given different discrimination thresholds, and computational time of template matching when different image filters are applied. Furthermore the best cases for each study are presented as comparison for the other results.In the end of the thesis we present how for screenshots with objects very similar to the templates used by the agent, template matching can result in a high degree of accuracy in both object localization and object identification and that a small reduction of similarity between template and screenshot to reduce the agent's ability to reliably identifying specific objects in the environment. [528] Rasmus Holm. 2016. Cluster Analysis of Discussions on Internet Forums. Student Thesis. 62 pages. ISRN: LIU-IDA/LITH-EX-G--16/037—SE. The growth of textual content on internet forums over the last decade have been immense which have resulted in users struggling to find relevant information in a convenient and quick way.The activity of finding information from large data collections is known as information retrieval and many tools and techniques have been developed to tackle common problems. Cluster analysis is a technique for grouping similar objects into smaller groups (clusters) such that the objects within a cluster are more similar than objects between clusters.We have investigated the clustering algorithms, Graclus and Non-Exhaustive Overlapping k-means (NEO-k-means), on textual data taken from Reddit, a social network service. One of the difficulties with the aforementioned algorithms is that both have an input parameter controlling how many clusters to find. We have used a greedy modularity maximization algorithm in order to estimate the number of clusters that exist in discussion threads.We have shown that it is possible to find subtopics within discussions and that in terms of execution time, Graclus has a clear advantage over NEO-k-means. [527] Erik Hansson. 2016. Search guidance with composite actions: Increasing the understandability of the domain model. Student Thesis. 98 pages. ISRN: LIU-IDA/LITH-EX--16/043--SE. This report presents an extension to the domain definition language for Threaded Forward-chaining Partial Order Planner (TFPOP) that can be used to increase the understandability of domain models. The extension consists of composite actions which is a method for expressing abstract actions as procedures of primitive actions. TFPOP can then uses these abstract actions when searching for a plan. An experiment, with students as participants, was used to show that using composite action can increase the understandability for non-expert users. Moreover, it was also proved the planner can utilize the composite action to significantly decrease the search time. Furthermore, indications was found that using composite actions is equally fast in terms of search time as using existing equivalent methods to decrease the search time. [526] Anna Boyer de la Giroday. 2016. Automatic fine tuning of cavity filters. Student Thesis. 49 pages. ISRN: LIU-IDA/LITH-EX-A--16/036--SE. Cavity filters are a necessary component in base stations used for telecommunication. Without these filters it would not be possible for base stations to send and receive signals at the same time. Today these cavity filters require fine tuning by humans before they can be deployed. This thesis have designed and implemented a neural network that can tune cavity filters. Different types of design parameters have been evaluated, such as neural network architecture, data presentation and data preprocessing. While the results was not comparable to human fine tuning, it was shown that there was a relationship between error and number of weights in the neural network. The thesis also presents some rules of thumb for future designs of neural network used for filter tuning. [525] Alexander Kleiner, Fredrik Heintz and Satoshi Tadokoro. 2016. Editorial Material: Editorial: Special Issue on Safety, Security, and Rescue Robotics (SSRR), Part 1 in JOURNAL OF FIELD ROBOTICS, vol 33, issue 3, pp 263-264. Journal of Field Robotics, 33(3):263–264. WILEY-BLACKWELL. DOI: 10.1002/rob.21653. n/a [524] Olov Andersson, Mariusz Wzorek, Piotr Rudol and Patrick Doherty. 2016. Model-Predictive Control with Stochastic Collision Avoidance using Bayesian Policy Optimization. In IEEE International Conference on Robotics and Automation (ICRA), 2016, pages 4597–4604. In series: Proceedings of IEEE International Conference on Robotics and Automation #??. Institute of Electrical and Electronics Engineers (IEEE). DOI: 10.1109/ICRA.2016.7487661. Robots are increasingly expected to move out of the controlled environment of research labs and into populated streets and workplaces. Collision avoidance in such cluttered and dynamic environments is of increasing importance as robots gain more autonomy. However, efficient avoidance is fundamentally difficult since computing safe trajectories may require considering both dynamics and uncertainty. While heuristics are often used in practice, we take a holistic stochastic trajectory optimization perspective that merges both collision avoidance and control. We examine dynamic obstacles moving without prior coordination, like pedestrians or vehicles. We find that common stochastic simplifications lead to poor approximations when obstacle behavior is difficult to predict. We instead compute efficient approximations by drawing upon techniques from machine learning. We propose to combine policy search with model-predictive control. This allows us to use recent fast constrained model-predictive control solvers, while gaining the stochastic properties of policy-based methods. We exploit recent advances in Bayesian optimization to efficiently solve the resulting probabilistically-constrained policy optimization problems. Finally, we present a real-time implementation of an obstacle avoiding controller for a quadcopter. We demonstrate the results in simulation as well as with real flight experiments. [523] Daniel de Leng and Fredrik Heintz. 2016. Qualitative Spatio-Temporal Stream Reasoning With Unobservable Intertemporal Spatial Relations Using Landmarks. In Dale Schuurmans, Dale Wellman, editors, Proceedings of the Thirtieth AAAI Conference on Artificial Intelligence (AAAI), pages 957–963. In series: Proceedings of the AAAI Conference on Artificial Intelligence #??. AAAI Press. ISBN: 978-1-57735-762-9. Link: http://www.aaai.org/ocs/index.php/AAAI/A... Qualitative spatio-temporal reasoning is an active research area in Artificial Intelligence. In many situations there is a need to reason about intertemporal qualitative spatial relations, i.e. qualitative relations between spatial regions at different time-points. However, these relations can never be explicitly observed since they are between regions at different time-points. In applications where the qualitative spatial relations are partly acquired by for example a robotic system it is therefore necessary to infer these relations. This problem has, to the best of our knowledge, not been explicitly studied before. The contribution presented in this paper is two-fold. First, we present a spatio-temporal logic MSTL, which allows for spatio-temporal stream reasoning. Second, we define the concept of a landmark as a region that does not change between time-points and use these landmarks to infer qualitative spatio-temporal relations between non-landmark regions at different time-points. The qualitative spatial reasoning is done in RCC-8, but the approach is general and can be applied to any similar qualitative spatial formalism. [522] Tommy Frnqvist, Fredrik Heintz, Patrick Lambrix, Linda Mannila and Chunyan Wang. 2016. Supporting Active Learning by Introducing an Interactive Teaching Tool in a Data Structures and Algorithms. In Proceedings of the 47th ACM Technical Symposium on Computer Science Education (SIGCSE 2016), pages 663–668. ACM Publications. ISBN: 978-1-4503-3685-7. DOI: 10.1145/2839509.2844653. Traditionally, theoretical foundations in data structures and algorithms (DSA) courses have been covered through lectures followed by tutorials, where students practise their understanding on pen-and-paper tasks. In this paper, we present findings from a pilot study on using the interactive e-book OpenDSA as the main material in a DSA course. The goal was to redesign an already existing course by building on active learning and continuous examination through the use of OpenDSA. In addition to presenting the study setting, we describe findings from four data sources: final exam, OpenDSA log data, pre and post questionnaires as well as an observation study. The results indicate that students performed better on the exam than during previous years. Students preferred OpenDSA over traditional textbooks and worked actively with the material, although a large proportion of them put off the work until the due date approaches. [521] Mikael Nilsson, Jonas Kvarnstrm and Patrick Doherty. 2016. Efficient Processing of Simple Temporal Networks with Uncertainty: Algorithms for Dynamic Controllability Verification. Acta Informatica, 53(6-8):723–752. Springer Publishing Company. DOI: 10.1007/s00236-015-0248-8. Temporal formalisms are essential for reasoning about actions that are carried out over time. The exact durations of such actions are generally hard to predict. In temporal planning, the resulting uncertainty is often worked around by only considering upper bounds on durations, with the assumption that when an action happens to be executed more quickly, the plan will still succeed. However, this assumption is often false: If we finish cooking too early, the dinner will be cold before everyone is ready to eat. Using Simple Temporal Networks with Uncertainty (STNU), a planner can correctly take both lower and upper duration bounds into account. It must then verify that the plans it generates are executable regardless of the actual outcomes of the uncertain durations. This is captured by the property of dynamic controllability (DC), which should be verified incrementally during plan generation. Recently a new incremental algorithm for verifying dynamic controllability was proposed: EfficiantIDC, which can verify if an STNU that is DC remains DC after the addition or tightening of a constraint (corresponding to a new action being added to a plan). The algorithm was shown to have a worst case complexity of O(n4) for each addition or tightening. This can be amortized over the construction of a whole STNU for an amortized complexity in O(n3). In this paper we improve the EfficientIDC algorithm in a way that prevents it from having to reprocess nodes. This improvement leads to a lower worst case complexity in O(n3). [520] Hkan Warnquist, Jonas Kvarnstrm and Patrick Doherty. 2016. A Modeling Framework for Troubleshooting Automotive Systems. Applied Artificial Intelligence, 30(3):257–296. Taylor & Francis. DOI: 10.1080/08839514.2016.1156955. Note: The published article is a shorter version than the version in manuscript form. The status of this article was earlier Manuscript.Funding agencies: Scania CV AB; FFI - Strategic Vehicle Research and Innovation; Excellence Center at Linkoping and Lund in Information Technology (ELLIIT); Research Council (VR) Linnaeus Center CADICS This article presents a novel framework for modeling the troubleshooting process for automotive systems such as trucks and buses. We describe how a diagnostic model of the troubleshooting process can be created using event-driven, nonstationary, dynamic Bayesian networks. Exact inference in such a model is in general not practically possible. Therefore, we evaluate different approximate methods for inference based on the Boyen–Koller algorithm. We identify relevant model classes that have particular structure such that inference can be made with linear time complexity. We also show how models created using expert knowledge can be tuned using statistical data. The proposed learning mechanism can use data that is collected from a heterogeneous fleet of modular vehicles that can consist of different components. The proposed framework is evaluated both theoretically and experimentally on an application example of a fuel injection system. 2015 [519] Fredrik Lfgren, Jon Dybeck and Fredrik Heintz. 2015. Qualification document: RoboCup 2015 Standard Platform League. In , pages 1–2. Qualification Video for RoboCup Standard Platform League 2015: https://www.youtube.com/watch?v=YNVzj6VL... fulltext:preprint: http://liu.diva-portal.org/smash/get/div... fulltext:preprint: http://liu.diva-portal.org/smash/get/div... This is the application for the RoboCup 2015 StandardPlatform League from the ”LiU Robotics” team. In thisdocument we present ourselves and what we want to achieve byour participation in the conference and competition [518] Erik Sandewall. 2015. Samtal om Sveriges nation. Book. Volibri frlag och IT. 154 pages. ISBN: 9789163792267. Find book at a Swedish library/Hitta boken i ett svenskt bibliotek: http://libris.kb.se/hitlist?d=libris&q=9... Demokratin ifrågasätts i dagens värld genom att auktoritära och fundamentalistiska ideologier av flera slag förs fram som alternativ. De tillämpas i praktiken i ett flertal länder, men de sprids också genom aktiv propaganda. Den här boken utgår från föreställningen att detta utgör en utmaning även för vårt land, och den föreslår framförallt två åtgärder för att möta den utmaningen.Ett förslag är att precisera samhällets demokratiska grundsatser och att komplettera dem med några ytterligare punkter, såsom följande. En princip om assimilationsfrihet formuleras, alltså en rättighet att byta etnisk, religiös eller politisk tillhörighet om man vill, och samtidigt förstås en rättighet att bevara den man har. I boken föreslås utvidgat skydd för dessa rättigheter. Likaså införs begreppet religionism, alltså hävdandet att en viss religion är överlägsen andra och är förutbestämd att ta över, och det föreslås att religionism ska likställas med rasism.Det andra huvudförslaget är att betrakta nationen som bäraren av detta utvidgade demokratibegrepp, men då handlar det om nationen i en annan bemärkelse än vad dagens nationalister' föreställer sig. Boken anknyter till skillnaden mellan etnisk och samhällelig nationalism (civic nationalism' på engelska). I den förra sökerman göra en etnisk grupp till en nation, i den senare ses nationen som fundamentet för staten och samhället, och som den samlande faktorn för alla medborgare som ansluter sig till det demokratiska samhällets principer.Boken hävdar också att en kunskap om Sveriges historia ur politisk och religiös synpunkt är viktig för att kunna relatera till de främmande ideologierna och för attförstå hur vår samhällsmodell förhåller sig till deras. [517] Stefan Brnd. 2015. Using Rigid Landmarks to Infer Inter-Temporal Spatial Relations in Spatio-Temporal Reasoning. Student Thesis. 32 pages. ISRN: LIU-IDA/LITH-EX-G--15/074--SE. Spatio-temporal reasoning is the area of automated reasoning about space and time and is important in the field of robotics. It is desirable for an autonomous robot to have the ability to reason about both time and space. ST0 is a logic that allows for such reasoning by, among other things, defining a formalism used to describe the relationship between spatial regions and a calculus that allows for deducing further information regarding such spatial relations. An extension of ST0 is ST1 that can be used to describe the relationship between spatial entities across time-points (inter-temporal relations) while ST0 is constrained to doing so within a single time-point. This allows for a better ability of expressing how spatial entities change over time. A major obstacle in using ST1 in practise however, is the fact that any observations made regarding spatial relations between regions is constrained to the time-point in which the observation was made, so we are unable to observe inter-temporal relations. Further complicating things is the fact that deducing such inter-temporal relations is not possible without a frame of reference. This thesis examines one method of overcoming these problems by considering the concept of rigid regions which are assumed to always be unchanging and using them as the frame of reference, or as landmarks. The effectiveness of this method is studied by conducting experiments where a comparison is made between various landmark ratios with respect to the total number of regions under consideration. Results show that when a high degree of intra-temporal relations are fully or partially known, increasing the number of landmark regions will reduce the percentage of inter-temporal relations to be completely unknown. Despite this, very few inter-temporal relations can be fully determined even with a high ratio of landmark regions. [516] Daniel de Leng. 2015. Querying Flying Robots and Other Things: Ontology-supported stream reasoning. XRDS: Crossroads, The ACM Magazine for Students, 22(2):44–47. Association for Computing Machinery (ACM). DOI: 10.1145/2845155. Link to publication: http://xrds.acm.org/article.cfm?aid=2845... [515] Valberg Joakim. 2015. Document Separation in Digital Mailrooms. Student Thesis. 47 pages. ISRN: LIU-IDA/LITH-EX-A-15/056-SE. The growing mail volumes for businesses worldwide is one reason why theyare increasingly turning to digital mailrooms. A digital mailroom automaticallymanages the incoming mails, and a vital technology to its success isdocument classication. A problem with digital mailrooms and the documentclassication is separating the input stream of pages into documents.This thesis investigates existing classication theory and applies it to createan algorithm which solves the document separation problem. This algorithmis evaluated and compared against an existing algorithmic solution, over adataset containing real invoices. [514] Tommy Frnqvist, Fredrik Heintz, Patrick Lambrix, Linda Mannila and Chunyan Wang. 2015. Supporting Active Learning Using an Interactive Teaching Tool in a Data Structures and Algorithms Course. In Proceedings of 5:e Utvecklingskonferensen fr Sveriges ingenjrsutbildningar (UtvSvIng), pages 76–79. In series: Technical report / Department of Information Technology, Uppsala University #2016-002. Fulltext: http://utvecklingskonferens.it.uu.se/fil... Traditionally, theoretical foundations in data structuresand algorithms (DSA) courses have been covered throughlectures followed by tutorials, where students practise theirunderstanding on pen-and-paper tasks. In this paper, we presentfindings from a pilot study on using the interactive e-bookOpenDSA as the main material in a DSA course. The goal was toredesign an already existing course by building on active learningand continuous examination through the use of OpenDSA. Inaddition to presenting the study setting, we describe findings fromfour data sources: final exam, OpenDSA log data, pre- and postcourse questionnaires as well as an observation study. The resultsindicate that students performed better on the exam than duringprevious years. Students preferred OpenDSA over traditionaltextbooks and worked actively with the material, although alarge proportion of them put off the work until the due dateapproaches. [513] Michal Grimsberg, Fredrik Heintz, Viggo Kann, Inger Erlander Klein and Lars hrstrm. 2015. Vem styr egentligen grundutbildningen?. In Proceedings of 5:e Utvecklingskonferensen fr Sveriges ingenjrsutbildningar (UtvSvIng). In series: Technical report / Department of Information Technology, Uppsala University #2016-002. Vi belyser olikheter och likheter i hur grundutbildningen styrs på fyra svenska tekniska högskolor. Vi jämför hur lärare och examinatorer väljs ut, hur medel fördelas och vilken roll programansvariga (eller motsvarande) har. De strukturella skillnaderna är relativt stora med störst autonomi för programansvariga på Chalmers tekniska högskola vilket delvis har att göra med att detta lärosäte lyder under aktiebolagslagen. [512] Fredrik Heintz, Aseel Berglund, Bjrn Hedin and Viggo Kann. 2015. En jmfrelse mellan programsamanhllande kurser vid KTH och LiU. In Proceedings of 5:e Utvecklingskonferensen fr Sveriges ingenjrsutbildningar (UtvSvIng). In series: Technical report / Department of Information Technology, Uppsala University #2016-002. Programsammanhållande kurser där studenter från årskurs 1-3 gemensamt reflekterar över teman med koppling till deras studier och framtida yrkesliv finns på både KTH och Linköpings universitet (LiU). Syftet med kurserna är främst att skapa en helhet i utbildningen och ge förståelse för vad den leder till, genom att få studenterna att reflektera över sina studier och sin kommande yrkesroll. Detta leder förhoppningsvis till ökad genomströmning och minskade avhopp. Kurserna har gemensamt ursprung men har utvecklats i olika riktningar. Artikeln jämför tre programsammanhållande kurser för Datateknik KTH, Medieteknik KTH samt Data- och mjukvaruteknik Linköpings universitet. [511] Fredrik Heintz, Tommy Frnqvist and Jesper Thorn. 2015. Programutvecklingsstrategier fr att ka kopplingen mellan programmering och matematik. In Proceedings of 5:e Utvecklingskonferensen fr Sveriges ingenjrsutbildningar (UtvSvIng). In series: Technical report / Department of Information Technology, Uppsala University #2016-002. Matematik och programmering är två viktiga inslag i civilingenjörsprogram inom data- och mjukvaruteknik. De studenter som klarar dessa kurser klarar sannolikt resten av utbildningen. Idag har fler studenter programmering än matematik som huvudsakligt intresse. Därför har Linköpings universitet aktivt jobbat med olika strategier för att öka kopplingen mellan programmering och matematik, främst i de inledande kurserna. För att undersöka studenternas attityder till matematik och programmering har vi genomfört flera enkätstudier som bl.a. visar att intresset för matematik är stort men intresset för programmering ännu större och att studenterna tror de kommer ha betydligt mer nytta av programmering än matematik under sin karriär. Texten är tänkt som grund för en diskussion kring hur kopplingarna mellan matematik och programmering kan göras tydligare och starkare. [510] Mikael Nilsson, Jonas Kvarnstrm and Patrick Doherty. 2015. Revisiting Classical Dynamic Controllability: A Tighter Complexity Analysis. In Béatrice Duval; Jaap van den Herik; Stephane Loiseau; Joaquim Filipe, editor, Agents and Artificial Intelligence: 6th International Conference, ICAART 2014, Angers, France, March 6?8, 2014, Revised Selected Papers, pages 243–261. In series: Lecture Notes in Computer Science #8946. Springer. ISBN: 978-3-319-25209-4, 978-3-319-25210-0. DOI: 10.1007/978-3-319-25210-0_15. Simple Temporal Networks with Uncertainty (STNUs) allow the representation of temporal problems where some durations are uncontrollable (determined by nature), as is often the case for actions in planning. It is essential to verify that such networks are dynamically controllable (DC) -- executable regardless of the outcomes of uncontrollable durations -- and to convert them to an executable form. We use insights from incremental DC verification algorithms to re-analyze the original, classical, verification algorithm. This algorithm is the entry level algorithm for DC verification, based on a less complex and more intuitive theory than subsequent algorithms. We show that with a small modification the algorithm is transformed from pseudo-polynomial to O(n4) which makes it still useful. We also discuss a change reducing the amount of work performed by the algorithm. [509] Hkan Warnquist. 2015. Troubleshooting Trucks: Automated Planning and Diagnosis. PhD Thesis. In series: Linkping Studies in Science and Technology. Dissertations #1691. Linkping University Electronic Press. 79 pages. ISBN: 978-91-7685-993-3. DOI: 10.3384/diss.diva-119445. This thesis considers computer-assisted troubleshooting of heavy vehicles such as trucks and buses. In this setting, the person that is troubleshooting a vehicle problem is assisted by a computer that is capable of listing possible faults that can explain the problem and gives recommendations of which actions to take in order to solve the problem such that the expected cost of restoring the vehicle is low. To achieve this, such a system must be capable of solving two problems: the diagnosis problem of finding which the possible faults are and the decision problem of deciding which action should be taken.The diagnosis problem has been approached using Bayesian network models. Frameworks have been developed for the case when the vehicle is in the workshop only and for remote diagnosis when the vehicle is monitored during longer periods of time.The decision problem has been solved by creating planners that select actions such that the expected cost of repairing the vehicle is minimized. New methods, algorithms, and models have been developed for improving the performance of the planner.The theory developed has been evaluated on models of an auxiliary braking system, a fuel injection system, and an engine temperature control and monitoring system. [508] Mattias Tiger and Fredrik Heintz. 2015. Towards Unsupervised Learning, Classification and Prediction of Activities in a Stream-Based Framework. In Proceedings of the Thirteenth Scandinavian Conference on Artificial Intelligence (SCAI). ISBN: 978-1-61499-588-3. länk till artikeln: https://www.ida.liu.se/divisions/aiics/p... Learning to recognize common activities such as traffic activities and robot behavior is an important and challenging problem related both to AI and robotics. We propose an unsupervised approach that takes streams of observations of objects as input and learns a probabilistic representation of the observed spatio-temporal activities and their causal relations. The dynamics of the activities are modeled using sparse Gaussian processes and their causal relations using a probabilistic graph. The learned model supports in limited form both estimating the most likely current activity and predicting the most likely future activities. The framework is evaluated by learning activities in a simulated traffic monitoring application and by learning the flight patterns of an autonomous quadcopter. [507] Daniel de Leng and Fredrik Heintz. 2015. Ontology-Based Introspection in Support of Stream Reasoning. In S. Nowaczyk, editor, Thirteenth scandinavian conference on artificial intelligence (SCAI), pages 78–87. IOS Press. ISBN: 9781614995883, 9781614995890. Link to publication: https://www.ida.liu.se/divisions/aiics/p... Building complex systems such as autonomous robots usually require the integration of a wide variety of components including high-level reasoning functionalities. One important challenge is integrating the information in a system by setting up the data flow between the components. This paper extends our earlier work on semantic matching with support for adaptive on-demand semantic information integration based on ontology-based introspection. We take two important standpoints. First, we consider streams of information, to handle the fact that information often becomes continually and incrementally available. Second, we explicitly represent the semantics of the components and the information that can be provided by them in an ontology. Based on the ontology our custom-made stream configuration planner automatically sets up the stream processing needed to generate the streams of information requested. Furthermore, subscribers are notified when properties of a stream changes, which allows them to adapt accordingly. Since the ontology represents both the systems information about the world and its internal stream processing many other powerful forms of introspection are also made possible. The proposed semantic matching functionality is part of the DyKnow stream reasoning framework and has been integrated in the Robot Operating System (ROS). [506] Barbara Dunin-Keplicz and Andrzej Szalas. 2015. A New Perspective on Goals. In Sujata Ghosh and Jakub Szymanik, editors, The Facts Matter: Essays on Logic and Cognition in Honour of Rineke Verbrugge, pages 50–66. College Publications. ISBN: 978-1-84890-173-5. Find book in another country/Hitta boken i ett annat land: http://www.worldcat.org/search?q=978-1-8... This book is in celebration of Rineke Verbrugge's 50th birthday. It is a product of an incredible effort on the part of Rineke's teachers, colleagues, students and friends who have all been won over by her ever-encouraging and positive presence in academia and also in daily life. Pertaining to Rineke's research interests, the book features eight articles on a wide range of topics - from theories of arithmetic to a study on autism. The papers on hybrid logic, formal theories of belief, probability, goals, social networks, and bisimulations enrich the logic section of the book while papers on cognitive strategizing and social cognition bring up the cognitive perspective. The themes themselves provide a compelling perception of the vast expanse of Rineke's academic interests and endeavours. A series of personal comments, stories, anecdotes, and pictures constitute the latter part of the book, adding a distinct personal touch to this volume. [505] Mikael Nilsson. 2015. Efficient Temporal Reasoning with Uncertainty. Licentiate Thesis. In series: Linkping Studies in Science and Technology. Thesis #1722. Linkping University Electronic Press. 116 pages. ISBN: 978-91-7685-991-9. DOI: 10.3384/lic.diva-119409. Automated Planning is an active area within Artificial Intelligence. With the help of computers we can quickly find good plans in complicated problem domains, such as planning for search and rescue after a natural disaster. When planning in realistic domains the exact duration of an action generally cannot be predicted in advance. Temporal planning therefore tends to use upper bounds on durations, with the explicit or implicit assumption that if an action happens to be executed more quickly, the plan will still succeed. However, this assumption is often false. If we finish cooking too early, the dinner will be cold before everyone is at home and can eat. Simple Temporal Networks with Uncertainty (STNUs) allow us to model such situations. An STNU-based planner must verify that the temporal problems it generates are executable, which is captured by the property of dynamic controllability (DC). If a plan is not dynamically controllable, adding actions cannot restore controllability. Therefore a planner should verify after each action addition whether the plan remains DC, and if not, backtrack. Verifying dynamic controllability of a full STNU is computationally intensive. Therefore, incremental DC verification algorithms are needed.We start by discussing two existing algorithms relevant to the thesis. These are the very first DC verification algorithm called MMV (by Morris, Muscettola and Vidal) and the incremental DC verification algorithm called FastIDC, which is based on MMV.We then show that FastIDC is not sound, sometimes labeling networks as dynamically controllable when they are not. We analyze the algorithm to pinpoint the cause and show how the algorithm can be modified to correctly and efficiently detect uncontrollable networks.In the next part we use insights from this work to re-analyze the MMV algorithm. This algorithm is pseudo-polynomial and was later subsumed by first an n5 algorithm and then an n4 algorithm. We show that the basic techniques used by MMV can in fact be used to create an n4 algorithm for verifying dynamic controllability, with a new termination criterion based on a deeper analysis of MMV. This means that there is now a comparatively easy way of implementing a highly efficient dynamic controllability verification algorithm. From a theoretical viewpoint, understanding MMV is important since it acts as a building block for all subsequent algorithms that verify dynamic controllability. In our analysis we also discuss a change in MMV which reduces the amount of regression needed in the network substantially.In the final part of the thesis we show that the FastIDC method can result in traversing part of a temporal network multiple times, with constraints slowly tightening towards their final values. As a result of our analysis we then present a new algorithm with an improved traversal strategy that avoids this behavior. The new algorithm, EfficientIDC, has a time complexity which is lower than that of FastIDC. We prove that it is sound and complete. [504] Linh Anh Nguyen, Thi-Bich-Loc Nguyen and Andrzej Szalas. 2015. Towards richer rule languages with polynomial data complexity for the Semantic Web. Data & Knowledge Engineering, 96-97(??):57–77. ELSEVIER SCIENCE BV. DOI: 10.1016/j.datak.2015.04.005. We introduce a Horn description logic called Horn-DL, which is strictly and essentially richer than Horn-Reg(1), Horn-SHTQ and Horn-SROIQ, while still has PTime data complexity. In comparison with Horn-SROIQ, Horn-DL additionally allows the universal role and assertions of the form irreflexive(s), -s(a, b), a b. More importantly, in contrast to all the well-known Horn fragments epsilon L, DL-Lite, DLP, Horn-SHIQ, and Horn-SROIQ of description logics, Horn-DL allows a form of the concept constructor \"universal restriction\" to appear at the left hand side of terminological inclusion axioms. Namely, a universal restriction can be used in such places in conjunction with the corresponding existential restriction. We develop the first algorithm with PTime data complexity for checking satisfiability of Horn-DL knowledge bases. [503] Daniel de Leng and Fredrik Heintz. 2015. Ontology-Based Introspection in Support of Stream Reasoning. In Odile Papini, Salem Benferhat, Laurent Garcia, Marie-Laure Mugnier, Eduardo Fermé, Thomas Meyer, Renata Wassermann, Torsten Hahmann, Ken Baclawski, Adila Krisnadhi, Pavel Klinov, Stefano Borgo and Oliver Kutz Daniele Porello15, editors, Proceedings of the Joint Ontology Workshops (JOWO 2015), Buenos Aires, Argentina, July 25-27, 2015: The Joint Ontology Workshops - Episode 1, pages 1–8. In series: CEUR Workshop Proceedings #??. Rheinisch-Westfaelische Technische Hochschule Aachen * Lehrstuhl Informatik V. Note: Workshops held at the 24th International Joint Conference on Artificial Intelligence - IJCAI 2015, Buenos Aires, Argentina, July 25-27, 2015 Link to publication: http://ceur-ws.org/Vol-1517/JOWO-15_FOfA... fulltext:postprint: http://liu.diva-portal.org/smash/get/div... Building complex systems such as autonomous robots usually require the integration of a wide variety of components including high-level reasoning functionalities. One important challenge is integrating the information in a system by setting up the data flow between the components. This paper extends our earlier work on semantic matching with support for adaptive on-demand semantic information integration based on ontology-based introspection. We take two important stand-points. First, we consider streams of information, to handle the fact that information often becomes continually and incrementally available. Second, we explicitly represent the semantics of the components and the information that can be provided by them in an ontology. Based on the ontology our custom-made stream configuration planner automatically sets up the stream processing needed to generate the streams of information requested. Furthermore, subscribers are notified when properties of a stream changes, which allows them to adapt accordingly. Since the ontology represents both the system's information about the world and its internal stream processing many other powerful forms of introspection are also made possible. The proposed semantic matching functionality is part of the DyKnow stream reasoning framework and has been integrated in the Robot Operating System (ROS). [502] Erik Sommarstrm. 2015. I am the Greatest Driver in the World!: -Does self-awareness of driving ability affect traffic safety behaviour?. Student Thesis. 43 pages. ISRN: LIU-IDA/KOGVET-A--15/008—SE. This simulator study aims to investigate if there is a relationship between self-awareness of driving ability and traffic safety behaviour. Self-awareness in this study is accurate self-evaluation of one’s abilities. By letting 97 participants (55-75 years old) drive the simulator and answering the Driver Skill Inventory (DSI; Warner et al., 2013) as well as the Multidimensional locus of control (T-loc; Özkan & Lajunen, 2005). A measure of self-awareness was computed using the residuals from regression line. Furthermore, this measure could show if a participant over-estimated or under-estimated their ability. Four self-awareness measures were made. The self-awareness measures were compared to traffic safety behaviour. Three different traffic safety measures were computed using specific events in the simulator scenario. The self-awareness measures were grouped into three groups; under-estimators, good self-awareness and over-estimators. These groups were then compared to each other with respect to traffic safety. A multivariate ANOVA was made to test for differences between the self-awareness groups but no significant main difference was found. The results showed no difference in traffic safety behaviour given the different levels of self-awareness. Furthermore, this could be a result of the old age of the sample group as self-awareness may only be relevant in a learning context. The conclusion of the study is that the analysis shows that there is no difference between over-estimators and under-estimators of driving ability, at least not in experienced older drivers. [501] Tina Danielsson. 2015. Portering frn Google Apps REST API till Microsoft Office 365 REST API. Student Thesis. 10 pages. ISRN: LiTH-IDA/ERASMUS-G--15/003--SE. Stress på arbetsplatsen relaterat till många inkommande och utgående kommunikationskanaler är ett reellt problem. Applikationer som samlar alla kanaler i samma verktyg kan hjälpa till på det här området. För att förenkla vid utveckling av en sådan applikation kan ett modulärt system skapas, där varje modul ser liknande ut och enkelt kan kopplas in i en huvudapplikation. Den här studien undersöker de problem som kan uppstå när flera tjänster ska integreras, mer specifikt genom att titta på hur en befintlig modul för e-post via Google Apps kan porteras för att stödja e-post via Microsoft Office 365. Arbetet har skett enligt metoder för testdriven portering och varje steg i porteringen har dokumenterats noggrant. Ett antal problemområden har identifierats och möjliga lösningar föreslås. Utfrån de problem som uppstått dras slutsatsen att de är av en sådan karaktär att de inte utgör något hinder för en portering. [500] Jonas Hietala. 2015. A Comparison of Katz-eig and Link-analysis for Implicit Feedback Recommender Systems. Student Thesis. 85 pages. ISRN: LIU-IDA/LITH-EX-A--15/026--SE. Link: http://www.jonashietala.se/masters_thesi... Recommendations are becoming more and more important in a world where there is an abundance of possible choices and e-commerce and content providers are featuring recommendations prominently. Recommendations based on explicit feedback, where user is giving feedback for example with ratings, has been a popular research subject. Implicit feedback recommender systems which passively collects information about the users is an area growing in interest. It makes it possible to generate recommendations based purely from a user's interactions history without requiring any explicit input from the users, which is commercially useful for a wide area of businesses. This thesis builds a recommender system based on implicit feedback using the recommendation algorithms katz-eig and link-analysis and analyzes and implements strategies for learning optimized parameters for different datasets. The resulting system forms the foundation for Comordo Technologies' commercial recommender system. [499] Fredrik Heintz, Linda Mannila, Karin Nygrds, Peter Parnes and Bjrn Regnell. 2015. Computing at School in Sweden ? Experiences fromIntroducing Computer Science within Existing Subjects. In Proceeding of the 8th International Conference on Informatics in Schools:Situation, Evolution, and Perspective (ISSEP). In series: Lecture Notes in Computer Science #9378. Springer. ISBN: 978-3-319-25395-4. Computing is no longer considered a subject area only relevant for anarrow group of professionals, but rather as a vital part of general education thatshould be available to all children and youth. Since making changes to nationalcurricula takes time, people are trying to find other ways of introducing childrenand youth to computing. In Sweden, several current initiatives by researchers andteachers aim at finding ways of working with computing within the current curriculum.In this paper we present case studies based on a selection of these initiativesfrom four major regions in Sweden and based on these case studies wepresent our ideas for how to move forward on introducing computational thinkingon a larger scale in Swedish education. [498] Mattias Tiger and Fredrik Heintz. 2015. Online Sparse Gaussian Process Regression for Trajectory Modeling. In 18th International Conference on Information Fusion (Fusion), 2015, pages 782–791. IEEE. ISBN: 9780982443866, 9780982443873. Link to full text: https://www.ida.liu.se/divisions/aiics/p... Trajectories are used in many target tracking and other fusion-related applications. In this paper we consider the problem of modeling trajectories as Gaussian processes and learning such models from sets of observed trajectories. We demonstrate that the traditional approach to Gaussian process regression is not suitable when modeling a set of trajectories. Instead we introduce an approach to Gaussian process trajectory regression based on an alternative way of combing two Gaussian process (GP) trajectory models and inverse GP regression. The benefit of our approach is that it works well online and efficiently supports sophisticated trajectory model manipulations such as merging and splitting of trajectory models. Splitting and merging is very useful in spatio-temporal activity modeling and learning where trajectory models are considered discrete objects. The presented method and accompanying approximation algorithm have time and memory complexities comparable to state of the art of regular full and approximative GP regression, while havinga more flexible model suitable for modeling trajectories. The novelty of our approach is in the very flexible and accurate model, especially for trajectories, and the proposed approximative method based on solving the inverse problem of Gaussian process regression. [497] Patrik Bergstrm. 2015. Automated Setup of Display Protocols. Student Thesis. 44 pages. ISRN: LIU-IDA/LITH-EX-A--15/014--SE. Link: http://urn.kb.se/resolve?urn=urn:nbn:se:... Radiologists' workload has been steadily increasing for decades. As digital technology matures it improves the workflow for radiology departments and decreases the time necessary to examine patients. Computer systems are widely used in health care and are for example used to view radiology images. To simplify this, display protocols based on examination data are used to automatically create a layout and hang images for the user. To cover a wide variety of examinations hundreds of protocols must be created, which is a time-consuming task and the system can still fail to hang series if strict requirements on the protocols are not met. To remove the need for this manual step we propose to use machine learning based on past manually corrected presentations. The classifiers are trained on the metadata in the examination and how the radiologist preferred to hang the series. The chosen approach was to create classifiers for different layout rules and then use these predictions in an algorithm for assigning series types to individual image slots according to categories based on metadata, similar to how display protocol works. The resulting presentations shows that the system is able to learn, but must increase its prediction accuracy if it is to be used commercially. Analyses of the different parts show that increased accuracy in early steps should improve overall success. [496] Martin Danelljan, Fahad Shahbaz Khan, Michael Felsberg, Karl Granstrm, Fredrik Heintz, Piotr Rudol, Mariusz Wzorek, Jonas Kvarnstrm and Patrick Doherty. 2015. A Low-Level Active Vision Framework for Collaborative Unmanned Aircraft Systems. In Lourdes Agapito, Michael M. Bronstein and Carsten Rother, editors, COMPUTER VISION - ECCV 2014 WORKSHOPS, PT I, pages 223–237. In series: Lecture Notes in Computer Science #8925. Springer Publishing Company. ISBN: 978-3-319-16177-8, 978-3-319-16178-5. DOI: 10.1007/978-3-319-16178-5_15. Micro unmanned aerial vehicles are becoming increasingly interesting for aiding and collaborating with human agents in myriads of applications, but in particular they are useful for monitoring inaccessible or dangerous areas. In order to interact with and monitor humans, these systems need robust and real-time computer vision subsystems that allow to detect and follow persons.In this work, we propose a low-level active vision framework to accomplish these challenging tasks. Based on the LinkQuad platform, we present a system study that implements the detection and tracking of people under fully autonomous flight conditions, keeping the vehicle within a certain distance of a person. The framework integrates state-of-the-art methods from visual detection and tracking, Bayesian filtering, and AI-based control. The results from our experiments clearly suggest that the proposed framework performs real-time detection and tracking of persons in complex scenarios [495] Karl Nygren. 2015. Trust Logics and Their Horn Fragments: Formalizing Socio-Cognitive Aspects of Trust. Student Thesis. 93 pages. ISRN: LiTH-MAT-EX--2015/01--SE. This thesis investigates logical formalizations of Castelfranchi and Falcone's (C&F) theory of trust [9, 10, 11, 12]. The C&F theory of trust defines trust as an essentially mental notion, making the theory particularly well suited for formalizations in multi-modal logics of beliefs, goals, intentions, actions, and time.Three different multi-modal logical formalisms intended for multi-agent systems are compared and evaluated along two lines of inquiry. First, I propose formal definitions of key concepts of the C&F theory of trust and prove some important properties of these definitions. The proven properties are then compared to the informal characterisation of the C&F theory. Second, the logics are used to formalize a case study involving an Internet forum, and their performances in the case study constitute grounds for a comparison. The comparison indicates that an accurate modelling of time, and the interaction of time and goals in particular, is integral for formal reasoning about trust.Finally, I propose a Horn fragment of the logic of Herzig, Lorini, Hubner, and Vercouter [25]. The Horn fragment is shown to be too restrictive to accurately express the considered case study. [494] Barbara Dunin-Keplicz, Alina Strachocka, Andrzej Szalas and Rineke Verbrugge. 2015. Paraconsistent semantics of speech acts. Neurocomputing, 151(2):943–952. Elsevier. DOI: 10.1016/j.neucom.2014.10.001. This paper discusses an implementation of four speech acts: assert, concede, request and challenge in a paraconsistent framework. A natural four-valued model of interaction yields multiple new cognitive situations. They are analyzed in the context of communicative relations, which partially replace the concept of trust. These assumptions naturally lead to six types of situations, which often require performing conflict resolution and belief revision. The particular choice of a rule-based, DATALOC. like query language 4QL as a four-valued implementation framework ensures that, in contrast to the standard two-valued approaches, tractability of the model is achieved. [493] Patrick Doherty and Andrzej Szalas. 2015. Stability, Supportedness, Minimality and Kleene Answer Set Programs. In Thomas Eiter, Hannes Strass, Mirosław Truszczynski, Stefan Woltran, editors, Advances in Knowledge Representation, Logic Programming, and Abstract Argumentation: Essays Dedicated to Gerhard Brewka on the Occasion of His 60th Birthday, pages 125–140. In series: Lecture Notes in Computer Science #9060. Springer. ISBN: 978-3-319-14725-3, 978-3-319-14726-0. DOI: 10.1007/978-3-319-14726-0_9. Link to full text: http://www.ida.liu.se/divisions/aiics/pu... Answer Set Programming is a widely known knowledge representation framework based on the logic programming paradigm that has been extensively studied in the past decades. The semantic framework for Answer Set Programs is based on the use of stable model semantics. There are two characteristics intrinsically associated with the construction of stable models for answer set programs. Any member of an answer set is supported through facts and chains of rules and those members are in the answer set only if generated minimally in such a manner. These two characteristics, supportedness and minimality, provide the essence of stable models. Additionally, answer sets are implicitly partial and that partiality provides epistemic overtones to the interpretation of disjunctiver ules and default negation. This paper is intended to shed light on these characteristics by defining a semantic framework for answer set programming based on an extended first-order Kleene logic with weak and strong negation. Additionally, a definition of strongly supported models is introduced, separate from the minimality assumption explicit in stable models. This is used to both clarify and generate alternative semantic interpretations for answer set programs with disjunctive rules in addition to answer set programs with constraint rules. An algorithm is provided for computing supported models and comparative complexity results between strongly supported and stable model generation are provided. [492] Olov Andersson, Fredrik Heintz and Patrick Doherty. 2015. Model-Based Reinforcement Learning in Continuous Environments Using Real-Time Constrained Optimization. In Blai Bonet and Sven Koenig, editors, Proceedings of the Twenty-Ninth AAAI Conference on Artificial Intelligence (AAAI), pages 2497–2503. AAAI Press. ISBN: 978-1-57735-698-1. fulltext:print: http://liu.diva-portal.org/smash/get/div... Reinforcement learning for robot control tasks in continuous environments is a challenging problem due to the dimensionality of the state and action spaces, time and resource costs for learning with a real robot as well as constraints imposed for its safe operation. In this paper we propose a model-based reinforcement learning approach for continuous environments with constraints. The approach combines model-based reinforcement learning with recent advances in approximate optimal control. This results in a bounded-rationality agent that makes decisions in real-time by efficiently solving a sequence of constrained optimization problems on learned sparse Gaussian process models. Such a combination has several advantages. No high-dimensional policy needs to be computed or stored while the learning problem often reduces to a set of lower-dimensional models of the dynamics. In addition, hard constraints can easily be included and objectives can also be changed in real-time to allow for multiple or dynamic tasks. The efficacy of the approach is demonstrated on both an extended cart pole domain and a challenging quadcopter navigation task using real data. 2014 [491] Hkan Warnquist, Mattias Nyberg and Jonas Biteus. 2014. Guided Integrated Remote and Workshop Troubleshooting of Heavy Trucks. International Journal of Commercial Vehicles, 7(1):25–36. SAE International. DOI: 10.4271/2014-01-0284. When a truck or bus suffers from a breakdown it is important that the vehicle comes back on the road as soon as possible. In this paper we present a prototype diagnostic decision support system capable of automatically identifying possible causes of a failure and propose recommended actions on how to get the vehicle back on the road as cost efficiently as possible.This troubleshooting system is novel in the way it integrates the remote diagnosis with the workshop diagnosis when providing recommendations. To achieve this integration, a novel planning algorithm has been developed that enables the troubleshooting system to guide the different users (driver, help-desk operator, and mechanic) through the entire troubleshooting process.In this paper we formulate the problem of integrated remote and workshop troubleshooting and present a working prototype that has been implemented to demonstrate all parts of the troubleshooting system. [490] Linh Anh Nguyen, Thi-Bich-Loc Nguyen and Andrzej Szalas. 2014. A Horn Fragment with PTime Data Complexity of Regular Description Logic with Inverse. VNU Journal of Computer Science and Communication Engineering, 30(4):14–28. Link to publication: http://www.jcsce.vnu.edu.vn/index.php/jc... We study a Horn fragment called Horn-RegI of the regular description logic with inverse RegI, which extends the description logic ALC with inverse roles and regular role inclusion axioms characterized by finite automata. In contrast to the well-known Horn fragments EL, DL-Lite, DLP, Horn-SHIQ and Horn-SROIQ of description logics, Horn-RegI allows a form of the concept constructor \"universal restriction\" to appear at the left hand side of terminological inclusion axioms, while still has PTIME data complexity. Namely, a universal restriction can be used in such places in conjunction with the corresponding existential restriction. We provide an algorithm with PTIME data complexity for checking satisfiability of Horn-RegI knowledge bases. [489] Lukasz Bialek and Andrzej Szalas. 2014. Lightweight Reasoning with Incomplete and Inconsistent Information: a Case Study. In 2014 IEEE/WIC/ACM International Joint Conferences on (Volume:3 ) Web Intelligence (WI) and Intelligent Agent Technologies (IAT),, pages 325–332. IEEE. ISBN: 978-1-4799-4143-8. DOI: 10.1109/WI-IAT.2014.184. Dealing with heterogeneous information sources and reasoning techniques allowing for incomplete and inconsistent information is one of current challenges in the area of knowledge representation and reasoning. We advocate for 4QL, a rule-based query language, as a proper tool allowing one to address these challenges. To justify this point of view we discuss a rescue robotics scenario for which a simulator has been developed and tested. In particular, we present a planner using 4QL and, therefore, capable to deal with lack of knowledge and inconsistencies. Through the case study we show that our approach allows one to use lightweight knowledge representation tools: due to the use of 4QL tractability of modeling and reasoning is guaranteed and high usability is achieved. [488] Barbara Dunin-Keplicz and Andrzej Szalas. 2014. Indeterministic Belief Structures. In Agent and Multi-Agent Systems: Technologies and Applications: Proceedings of the 8th International Conference KES-AMSTA 2014, Chania, Greece, June 2014, pages 57–66. In series: Advances in Intelligent Systems and Computing #296. Springer International Publishing. ISBN: 978-3-319-07649-2, 978-3-319-07650-8. DOI: 10.1007/978-3-319-07650-8_7. The current paper falls into a bigger research programme concerning construction of modern belief structures applicable in multiagent systems. In previous papers we approached individual and group beliefs via querying paraconsistent belief bases. This framework, covering deterministic belief structures, turned out to be tractable under some natural restrictions on implementation. Moreover, we have indicated a four-valued query language 4QL as an implementation tool guaranteeing tractability and capturing all PTime -constructible belief structures.In this paper we generalize our approach to the nondeterministic case. This is achieved by adjusting the key abstractions of epistemic profiles and belief structures to this new situation. Importantly, tractability of the approach is still maintained. [487] Barbara Dunin-Keplicz, Andrzej Szalas and Rineke Verbrugge. 2014. Tractable Reasoning about Group Beliefs. In ENGINEERING MULTI-AGENT SYSTEMS, EMAS 2014, pages 328–350. In series: Lecture Notes in Computer Science #8758. SPRINGER INT PUBLISHING AG. ISBN: 978-3-319-14484-9, 978-3-319-14483-2. DOI: 10.1007/978-3-319-14484-9_17. In contemporary autonomous systems, like robotics, the need to apply group knowledge has been growing consistently with the increasing complexity of applications, especially those involving teamwork. However, classical notions of common knowledge and common belief, as well as their weaker versions, are too complex. Also, when modeling real-world situations, lack of knowledge and inconsistency of information naturally appear. Therefore, we propose a shift in perspective from reasoning in multi-modal logics to querying paraconsistent knowledge bases. This opens the possibility for exploring a new approach to group beliefs. To demonstrate expressiveness of our approach, examples of social procedures leading to complex belief structures are constructed via the use of epistemic profiles. To achieve tractability without compromising the expressiveness, as an implementation tool we choose 4QL, a four-valued rule-based query language. This permits both to tame inconsistency in individual and group beliefs and to execute the social procedures in polynomial time. Therefore, a marked improvement in efficiency has been achieved over systems such as (dynamic) epistemic logics with common knowledge and ATL, for which problems like model checking and satisfiability are PSPACE- or even EXPTIME-hard. [486] Aseel Berglund and Fredrik Heintz. 2014. Integrating Soft Skills into Engineering Education for Increased Student Throughput and more Professional Engineers. In Proceedings of LTHs 8:e Pedagogiska Inspirationskonferens (PIK). Lunds university. Link to publication: http://www.lth.se/fileadmin/lth/genombro... Soft skills are recognized as crucial for engineers as technical work is becoming more and more collaborative and interdisciplinary. Today many engineering educations fail to give appropriate training in soft skills. Linköping University has therefore developed a completely new course “Professionalism for Engineers” for two of its 5-year engineering programs in the area of computer science. The course stretches over the first 3 years with students from the three years taking it together. The purpose of the course is to give engineering students training in soft skills that are of importance during the engineering education as well as during their professional career. The examination is based on the Dialogue Seminar Method developed for learning from experience and through reflection. The organization of the course is innovative in many ways. [485] Alexander Bock, Alexander Kleiner, Jonas Lundberg and Timo Ropinski. 2014. Supporting Urban Search & Rescue Mission Planning through Visualization-Based Analysis. In Proceedings of the Vision, Modeling, and Visualization Conference 2014. Eurographics - European Association for Computer Graphics. ISBN: 978-3-905674-74-3. DOI: 10.2312/vmv.20141275. We propose a visualization system for incident commanders in urban search~\&~rescue scenarios that supports access path planning for post-disaster structures. Utilizing point cloud data acquired from unmanned robots, we provide methods for assessment of automatically generated paths. As data uncertainty and a priori unknown information make fully automated systems impractical, we present a set of viable access paths, based on varying risk factors, in a 3D environment combined with the visual analysis tools enabling informed decisions and trade-offs. Based on these decisions, a responder is guided along the path by the incident commander, who can interactively annotate and reevaluate the acquired point cloud to react to the dynamics of the situation. We describe design considerations for our system, technical realizations, and discuss the results of an expert evaluation. [484] S.T. Cao, L.A. Nguyen and Andrzej Szalas. 2014. The web ontology rule language OWL 2 RL+ and its extensions. In Gerhard Goos, Juris Hartmanis, and Jan van Leeuwen, editors, Transactions on Computational Collective Intelligence XIII, pages 152–175. In series: Lecture Notes in Computer Science #8342. Springer Verlag (Germany). ISBN: 978-3-642-54454-5. DOI: 10.1007/978-3-642-54455-2_7. It is known that the OWL 2RL Web Ontology Language Profile has PTime data complexity and can be translated into Datalog. However, the result of translation may consist of a Datalog program and a set of constraints in the form of negative clauses. Therefore, a knowledge base in OWL 2RL may be unsatisfiable. In the current paper we first identify a maximal fragment of OWL 2RL, called OWL 2RL+, with the property that every knowledge base expressed in OWL2RL+ can be translated to a Datalog program and hence is satisfiable. We then propose some extensions of OWL 2RL and OWL 2RL + that still have PTime data complexity. © 2014 Springer-Verlag Berlin Heidelberg. [483] Andrzej Szalas. 2014. Symbolic Explanations of Generalized Fuzzy Reasoning. In SMART DIGITAL FUTURES 2014, pages 7–16. In series: Frontiers in Artificial Intelligence and Applications #??. IOS Press. ISBN: 978-1-61499-405-3; 978-1-61499-404-6. DOI: 10.3233/978-1-61499-405-3-7. Various generalizations of fuzzy reasoning are frequently used in decision making. While in many application areas it is natural to assume that truth degrees of a property and its complement sum up to 1, such an assumption appears problematic, e.g., in modeling ignorance. Therefore, in some generalizations of fuzzy sets, degrees of membership in a set and in its complement are separated and are no longer required to sum up to 1. In frequent cases, this separation of positive and negative evidences for concept membership is more natural. As we discuss in the current paper, symbolic explanations of results of such forms of reasoning provide additional important information. In the present paper we address two related questions: (i) given generalized fuzzy connectives and a finite set of truth values T, find a finitely-valued logic over T, explaining fuzzy reasoning, and (ii) given a finitely-valued logic, find a fuzzy semantics, explained by the given logic. We also show examples illustrating usefulness of the approach. [482] Patrick Doherty, Jonas Kvarnstrm, Mariusz Wzorek, Piotr Rudol, Fredrik Heintz and Gianpaolo Conte. 2014. HDRC3 - A Distributed Hybrid Deliberative/Reactive Architecture for Unmanned Aircraft Systems. In Kimon P. Valavanis, George J. Vachtsevanos, editors, Handbook of Unmanned Aerial Vehicles, pages 849–952. Springer Science+Business Media B.V.. ISBN: 978-90-481-9706-4, 978-90-481-9707-1. DOI: 10.1007/978-90-481-9707-1_118. Find book at a Swedish library/Hitta boken i ett svenskt bibliotek: http://libris.kb.se/bib/16541662 Find book in another country/Hitta boken i ett annat land: http://www.worldcat.org/search?qt=worldc... This chapter presents a distributed architecture for unmanned aircraft systems that provides full integration of both low autonomy and high autonomy. The architecture has been instantiated and used in a rotorbased aerial vehicle, but is not limited to use in particular aircraft systems. Various generic functionalities essential to the integration of both low autonomy and high autonomy in a single system are isolated and described. The architecture has also been extended for use with multi-platform systems. The chapter covers the full spectrum of functionalities required for operation in missions requiring high autonomy. A control kernel is presented with diverse flight modes integrated with a navigation subsystem. Specific interfaces and languages are introduced which provide seamless transition between deliberative and reactive capability and reactive and control capability. Hierarchical Concurrent State Machines are introduced as a real-time mechanism for specifying and executing low-level reactive control. Task Specification Trees are introduced as both a declarative and procedural mechanism for specification of high-level tasks. Task planners and motion planners are described which are tightly integrated into the architecture. Generic middleware capability for specifying data and knowledge flow within the architecture based on a stream abstraction is also described. The use of temporal logic is prevalent and is used both as a specification language and as an integral part of an execution monitoring mechanism. Emphasis is placed on the robust integration and interaction between these diverse functionalities using a principled architectural framework. The architecture has been empirically tested in several complex missions, some of which are described in the chapter. [481] Cyrille Berger. 2014. Strokes detection for skeletonisation of characters shapes. In George Bebis, Richard Boyle, Bahram Parvin, Darko Koracin, Ryan McMahan, Jason Jerald, Hui Zhang, Steven M. Drucker, Chandra Kambhamettu, Maha El Choubassi, Zhigang Deng, Mark Carlson, editors, Advances in Visual Computing: 10th International Symposium, ISVC 2014, Las Vegas, NV, USA, December 8-10, 2014, Proceedings, Part II, pages 510–520. In series: Lecture Notes in Computer Science #8888. Springer. ISBN: 978-3-319-14364-4, 978-3-319-14363-7. DOI: 10.1007/978-3-319-14364-4_49. Skeletonisation is a key process in character recognition in natural images. Under the assumption that a character is made of a stroke of uniform colour, with small variation in thickness, the process of recognising characters can be decomposed in the three steps. First the image is segmented, then each segment is transformed into a set of connected strokes (skeletonisation), which are then abstracted in a descriptor that can be used to recognise the character. The main issue with skeletonisation is the sensitivity with noise, and especially, the presence of holes in the masks. In this article, a new method for the extraction of strokes is presented, which address the problem of holes in the mask and does not use any parameters. [480] Cyrille Berger. 2014. Colour perception graph for characters segmentation. In George Bebis, Richard Boyle, Bahram Parvin, Darko Koracin, Ryan McMahan, Jason Jerald, Hui Zhang, Steven M. Drucker, Chandra Kambhamettu, Maha El Choubassi, Zhigang Deng, Mark Carlson, editors, Advances in Visual Computing: 10th International Symposium, ISVC 2014, Las Vegas, NV, USA, December 8-10, 2014, Proceedings, pages 598–608. In series: Lecture Notes in Computer Science #8888. Springer. ISBN: 978-3-319-14364-4, 978-3-319-14363-7. DOI: 10.1007/978-3-319-14364-4_58. Characters recognition in natural images is a challenging problem, asit involves segmenting characters of various colours on various background. Inthis article, we present a method for segmenting images that use a colour percep-tion graph. Our algorithm is inspired by graph cut segmentation techniques andit use an edge detection technique for filtering the graph before the graph-cut aswell as merging segments as a final step. We also present both qualitative andquantitative results, which show that our algorithm perform at slightly better andfaster to a state of the art algorithm. [479] Mattias Tiger. 2014. Unsupervised Spatio-Temporal Activity Learning and Recognition in a Stream Processing Framework. Student Thesis. 103 pages. ISRN: LIU-IDA/LITH-EX-A--14/059--SE. Learning to recognize and predict common activities, performed by objects and observed by sensors, is an important and challenging problem related both to artificial intelligence and robotics.In this thesis, the general problem of dynamic adaptive situation awareness is considered and we argue for the need for an on-line bottom-up approach.A candidate for a bottom layer is proposed, which we consider to be capable of future extensions that can bring us closer towards the goal.We present a novel approach to adaptive activity learning, where a mapping between raw data and primitive activity concepts are learned and continuously improved on-line and unsupervised. The approach takes streams of observations of objects as input and learns a probabilistic representation of both the observed spatio-temporal activities and their causal relations. The dynamics of the activities are modeled using sparse Gaussian processes and their causal relations using probabilistic graphs.The learned model supports both estimating the most likely activity and predicting the most likely future (and past) activities. Methods and ideas from a wide range of previous work are combined to provide a uniform and efficient way to handle a variety of common problems related to learning, classifying and predicting activities.The framework is evaluated both by learning activities in a simulated traffic monitoring application and by learning the flight patterns of an internally developed autonomous quadcopter system. The conclusion is that our framework is capable of learning the observed activities in real-time with good accuracy.We see this work as a step towards unsupervised learning of activities for robotic systems to adapt to new circumstances autonomously and to learn new activities on the fly that can be detected and predicted immediately. [478] L.A. Nguyen, T.-B.-L. Nguyen and Andrzej Szalas. 2014. On horn knowledge bases in regular description logic with inverse. In KNOWLEDGE AND SYSTEMS ENGINEERING (KSE 2013), VOL 1, pages 37–49. In series: Advances in Intelligent Systems and Computing #Vol 244. Springer Berlin/Heidelberg. ISBN: 9783319027401. DOI: 10.1007/978-3-319-02741-8_6. We study a Horn fragment called Horn-RegI of the regular description logic with inverse RegI, which extends the description logic ALC with inverse roles and regular role inclusion axioms characterized by finite automata. In contrast to the well-known Horn fragmentsEL, DL-Lite, DLP, Horn-SH IQ and Horn-SROIQof description logics, Horn-RegI allows a form of the concept constructor universal restriction to appear at the left hand side of terminological inclusion axioms, while still has PTIME data complexity. Namely, a universal restriction can be used in such places in conjunction with the corresponding existential restriction. We provide an algorithm with PTIME data complexity for checking satisfiability of Horn-RegI knowledge bases. [477] Mattias Tiger and Fredrik Heintz. 2014. Towards Learning and Classifying Spatio-Temporal Activities in a Stream Processing Framework. In Ulle Endriss and João Leite, editors, STAIRS 2014: Proceedings of the 7th European Starting AI Researcher Symposium, pages 280–289. In series: Frontiers in Artificial Intelligence and Applications #264. IOS Press. ISBN: 978-1-61499-420-6, 978-1-61499-421-3. DOI: 10.3233/978-1-61499-421-3-280. Fulltext: https://doi.org/10.3233/978-1-61499-421-... Ebook: STAIRS 2014: http://ebooks.iospress.nl/volume/stairs-... We propose an unsupervised stream processing framework that learns a Bayesian representation of observed spatio-temporal activities and their causal relations. The dynamics of the activities are modeled using sparse Gaussian processes and their causal relations using a causal Bayesian graph. This allows the model to be efficient through compactness and sparsity in the causal graph, and to provide probabilities at any level of abstraction for activities or chains of activities. Methods and ideas from a wide range of previous work are combined and interact to provide a uniform way to tackle a variety of common problems related to learning, classifying and predicting activities. We discuss how to use this framework to perform prediction of future activities and to generate events. [476] Oleg Burdakov, Patrick Doherty and Jonas Kvarnstrm. 2014. Local Search for Hop-constrained Directed Steiner Tree Problem with Application to UAV-based Multi-target Surveillance. In Butenko, S., Pasiliao, E.L., Shylo, V., editors, Examining Robustness and Vulnerability of Networked Systems, pages 26–50. In series: NATO Science for Peace and Security Series - D: Information and Communication Security #37. IOS Press. ISBN: 978-1-61499-390-2, 978-1-61499-391-9. DOI: 10.3233/978-1-61499-391-9-26. Find book in another country/Hitta boken i ett annat land: http://www.worldcat.org/search?q=978-1-6... We consider the directed Steiner tree problem (DSTP) with a constraint on the total number of arcs (hops) in the tree. This problem is known to be NP-hard, and therefore, only heuristics can be applied in the case of its large-scale instances.For the hop-constrained DSTP, we propose local search strategies aimed at improving any heuristically produced initial Steiner tree. They are based on solving a sequence of hop-constrained shortest path problems for which we have recently developed efficient label correcting algorithms.The presented approach is applied to finding suitable 3D locations where unmanned aerial vehicles (UAVs) can be placed to relay information gathered in multi-target monitoring and surveillance. The efficiency of our algorithms is illustrated by results of numerical experiments involving problem instances with up to 40 000 nodes and up to 20 million arcs. [475] Oleg Burdakov, Patrick Doherty and Jonas Kvarnstrm. 2014. Optimal Scheduling for Replacing Perimeter Guarding Unmanned Aerial Vehicles. Technical Report. In series: LiTH-MAT-R #2014:09. Linkping University Electronic Press. 16 pages. Guarding the perimeter of an area in order to detect potential intruders is an important task in a variety of security-related applications. This task can in many circumstances be performed by a set of camera-equipped unmanned aerial vehicles (UAVs). Such UAVs will occasionally require refueling or recharging, in which case they must temporarily be replaced by other UAVs in order to maintain complete surveillance of the perimeter. In this paper we consider the problem of scheduling such replacements. We present optimal replacement strategies and justify their optimality. [474] Oleg Burdakov, Patrick Doherty and Jonas Kvarnstrm. 2014. Local Search for Hop-constrained Directed Steiner Tree Problem with Application to UAV-based Multi-target Surveillance. Technical Report. In series: LiTH-MAT-R #2014:10. Linkping University Electronic Press. 25 pages. We consider the directed Steiner tree problem (DSTP) with a constraint on the total number of arcs (hops) in the tree. This problem is known to be NP-hard, and therefore, only heuristics can be applied in the case of its large-scale instances. For the hop-constrained DSTP, we propose local search strategies aimed at improving any heuristically produced initial Steiner tree. They are based on solving a sequence of hop-constrained shortest path problems for which we have recently developed ecient label correcting algorithms. The presented approach is applied to nding suitable 3D locations where unmanned aerial vehicles (UAVs) can be placed to relay information gathered in multi-target monitoring and surveillance. The eciency of our algorithms is illustrated by results of numerical experiments involving problem instances with up to 40 000 nodes and up to 20 million arcs. [473] Gianpaolo Conte, Piotr Rudol and Patrick Doherty. 2014. Evaluation of a Light-weight Lidar and a Photogrammetric System for Unmanned Airborne Mapping Applications: [Bewertung eines Lidar-systems mit geringem Gewicht und eines photogrammetrischen Systems fr Anwendungen auf einem UAV]. Photogrammetrie - Fernerkundung - Geoinformation, ??(4):287–298. E. Schweizerbart'sche Verlagsbuchhandlung. Link to article: http://www.ingentaconnect.com/content/sc... This paper presents a comparison of two light-weight and low-cost airborne mapping systems. One is based on a lidar technology and the other on a video camera. The airborne lidar system consists of a high-precision global navigation satellite system (GNSS) receiver, a microelectromechanical system (MEMS) inertial measurement unit, a magnetic compass and a low-cost lidar scanner. The vision system is based on a consumer grade video camera. A commercial photogrammetric software package is used to process the acquired images and generate a digital surface model. The two systems are described and compared in terms of hardware requirements and data processing. The systems are also tested and compared with respect to their application on board of an unmanned aerial vehicle (UAV). An evaluation of the accuracy of the two systems is presented. Additionally, the multi echo capability of the lidar sensor is evaluated in a test site covered with dense vegetation. The lidar and the camera systems were mounted and tested on-board an industrial unmanned helicopter with maximum take-off weight of around 100 kilograms. The presented results are based on real flight-test data. [472] Fredrik Heintz and Daniel de Leng. 2014. Spatio-Temporal Stream Reasoning with Incomplete Spatial Information. In Torsten Schaub, Gerhard Friedrich and Barry O'Sullivan, editors, Proceedings of the Twenty-first European Conference on Artificial Intelligence (ECAI'14), August 18-22, 2014, Prague, Czech Republic, pages 429–434. In series: Frontiers in Artificial Intelligence and Applications #263. IOS Press. ISBN: 978-1-61499-418-3, 978-1-61499-419-0. DOI: 10.3233/978-1-61499-419-0-429. Reasoning about time and space is essential for many applications, especially for robots and other autonomous systems that act in the real world and need to reason about it. In this paper we present a pragmatic approach to spatio-temporal stream reasoning integrated in the Robot Operating System through the DyKnow framework. The temporal reasoning is done in the Metric Temporal Logic and the spatial reasoning in the Region Connection Calculus RCC-8. Progression is used to evaluate spatio-temporal formulas over incrementally available streams of states. To handle incomplete information the underlying first-order logic is extended to a three-valued logic. When incomplete spatial information is received, the algebraic closure of the known information is computed. Since the algebraic closure might have to be re-computed every time step, we separate the spatial variables into static and dynamic variables and reuse the algebraic closure of the static variables, which reduces the time to compute the full algebraic closure. The end result is an efficient and useful approach to spatio-temporal reasoning over streaming information with incomplete information. [471] Daniel de Leng and Fredrik Heintz. 2014. Towards On-Demand Semantic Event Processing for Stream Reasoning. In 17th International Conference on Information Fusion. ISBN: 9788490123553. The ability to automatically, on-demand, apply pattern matching over streams of information to infer the occurrence of events is an important fusion functionality. Existing event detection approaches require explicit configuration of what events to detect and what streams to use as input. This paper discusses on-demand semantic event processing, and extends the semantic information integration approach used in the stream processing middleware framework DyKnow to incorporate this new feature. By supporting on-demand semantic event processing, systems can automatically configure what events to detect and what streams to use as input for the event detection. This can also include the detection of lower-level events as well as processing of streams. The semantic stream query language C-SPARQL is used to specify events, which can be seen as transformations over streams. Since semantic streams consist of RDF triples, we suggest a method to convert between RDF streams and DyKnow streams. DyKnow is integrated in the Robot Operating System (ROS) and used for example in collaborative unmanned aircraft systems missions. [470] Mikael Nilsson, Jonas Kvarnstrm and Patrick Doherty. 2014. Incremental Dynamic Controllability in Cubic Worst-Case Time. In Cesta, A; Combi, C; Laroussinie, F, editors, Proceedings of the 21st International Symposium on Temporal Representation and Reasoning (TIME), pages 17–26. In series: International Workshop on Temporal Representation and Reasoning. Proceedings #??. IEEE Computer Society Digital Library. ISBN: 978-1-4799-4227-5. DOI: 10.1109/TIME.2014.13. It is generally hard to predict the exact duration of an action. The uncertainty in the duration is often modeled in temporal planning by the use of upper bounds on durations, with the assumption that if an action happens to be executed more quickly, the plan will still succeed. However, this assumption is often false: If we finish cooking too early, the dinner will be cold before everyone is ready to eat. Simple Temporal Problems with Uncertainty (STPUs) allow us to model such situations. An STPU-based planner must verify that the plans it generates are executable, captured by the property of dynamic controllability. The EfficientIDC (EIDC) algorithm can do this incrementally during planning, with an amortized complexity per step of $O(n^3)$ but a worst-case complexity per step of $O(n^4)$. In this paper we show that the worst-case run-time of EIDC does occur, leading to repeated reprocessing of nodes in the STPU while verifying the dynamic controllability property. We present a new version of the algorithm, called EIDC2, which through optimal ordering of nodes avoids any need for reprocessing. This gives EIDC2 a strictly lower worst-case run-time, making it the fastest known algorithm for incrementally verifying dynamic controllability of STPUs. [469] Per Jonsson. 2014. Design och implementation av webbenkter: kvalitet, svarsfrekvens och underhll. Student Thesis. 10 pages. ISRN: LIU-IDA/LITH-EX-G--14/049--SE. En webbapplikation för analys och administration av webbenkäter har designats och implementerats. Dess syfte är att maximera svarskvalitet och svarsfrekvens samt att vara underhållbar. Uppdragsgivaren Ericsson Linköping har utfärdat kravspecifikationen för applikationen. Hänsyn har tagits till aspekterna webbenkätdesign och under-hållbarhet av mjukvara. Underhållbarhetsmodeller för mjukvara med tillhörande metriker, samt designmodeller och rekommendationer för webbenkäter har studerats. Arbetets bidrag till dessa områden är en praktisk modell som tillämpar rådande forskning, i form av en webbapplikation. Applikationen har testats mot modeller och rekommendationer för underhållbarhet och enkätdesign. Applikationen uppvisar hög grad av analyserbarhet, förändringsbarhet och testbarhet, men inte stabilitet. Effekten av enkätdesignen har inte utvärderats. Modellen för underhållbarhet kan klarlägga orsak och verkan i mjukvarusystem och bidra till utveckling av programvara med hög kvalitet. [468] Son Thanh Cao, Linh Anh Nguyen and Andrzej Szalas. 2014. WORL: a nonmonotonic rule language for the semantic web. Vietnam Journal of Computer Science, 1(1):57–69. Springer Berlin/Heidelberg. DOI: 10.1007/s40595-013-0009-y. We develop a new Web ontology rule language, called WORL, which combines a variant of OWL 2 RL with eDatalog ¬ . We allow additional features like negation, the minimal number restriction and unary external checkable predicates to occur at the left-hand side of concept inclusion axioms. Some restrictions are adopted to guarantee a translation into eDatalog ¬ . We also develop the well-founded semantics and the stable model semantics for WORL as well as the standard semantics for stratified WORL (SWORL) via translation into eDatalog ¬ . Both WORL with respect to the well-founded semantics and SWORL with respect to the standard semantics have PTime data complexity. In contrast to the existing combined formalisms, in WORL and SWORL negation in concept inclusion axioms is interpreted using nonmonotonic semantics. [467] Anders Wikstrm. 2014. Resource allocation of drones flown in a simulated environment. Student Thesis. 24 pages. ISRN: LIU-IDA/LITH-EX-G--14/003—SE. In this report we compare three different assignment algorithms in how they can be used to assign a set of drones to get to a set of goal locations in an as resource efficient way as possible. An experiment is set up to compare how these algorithms perform in a somewhat realistic simulated environment. The Robot Operating system (ROS) is used to create the experimental environment. We found that by introducing a threshold for the Hungarian algorithm we could reduce the total time it takes to complete the problem while only sightly increasing total distance traversed by the drones. [466] Mikael Nilsson, Jonas Kvarnstrm and Patrick Doherty. 2014. EfficientIDC: A Faster Incremental Dynamic Controllability Algorithm. In Proceedings of the 24th International Conference on Automated Planning and Scheduling (ICAPS), pages 199–207. AAAI Press. ISBN: 978-1-57735-660-8. Simple Temporal Networks with Uncertainty (STNUs) allow the representation of temporal problems where some durations are uncontrollable (determined by nature), as is often the case for actions in planning. It is essential to verify that such networks are dynamically controllable (DC) – executable regardless of the outcomes of uncontrollable durations – and to convert them to an executable form. We use insights from incremental DC verification algorithms to re-analyze the original verification algorithm. This algorithm, thought to be pseudo-polynomial and subsumed by an O(n5) algorithm and later an O(n4) algorithm, is in fact O(n4) given a small modification. This makes the algorithm attractive once again, given its basis in a less complex and more intuitive theory. Finally, we discuss a change reducing the amount of work performed by the algorithm. [465] Mikael Nilsson, Jonas Kvarnstrm and Patrick Doherty. 2014. Classical Dynamic Controllability Revisited: A Tighter Bound on the Classical Algorithm. In Proceedings of the 6th International Conference on Agents and Artificial Intelligence (ICAART), pages 130–141. ISBN: 978-989-758-015-4. DOI: 10.5220/0004815801300141. Simple Temporal Networks with Uncertainty (STNUs) allow the representation of temporal problems wheresome durations are uncontrollable (determined by nature), as is often the case for actions in planning. It is essentialto verify that such networks are dynamically controllable (DC) – executable regardless of the outcomesof uncontrollable durations – and to convert them to an executable form. We use insights from incrementalDC verification algorithms to re-analyze the original verification algorithm. This algorithm, thought to bepseudo-polynomial and subsumed by an O(n5) algorithm and later an O(n4) algorithm, is in fact O(n4) givena small modification. This makes the algorithm attractive once again, given its basis in a less complex andmore intuitive theory. Finally, we discuss a change reducing the amount of work performed by the algorithm. [464] Erik Sandewall. 2014. Editorial Material: A perspective on the early history of artificial intelligence in Europe. AI Communications, 27(1):81–86. IOS Press. DOI: 10.3233/AIC-130585. n/a [463] Fredrik Heintz and Inger Erlander Klein. 2014. The Design of Sweden's First 5-year Computer Science and Software Engineering Program. In Proceedings of the 45th ACM Technical Symposium on Computer Science Education (SIGCSE 2014), pages 199–204. ACM Press. ISBN: 978-1-4503-2605-6. DOI: 10.1145/2538862.2538925. [462] Gurkan Tuna, Bilel Nefzi and Gianpaolo Conte. 2014. Unmanned aerial vehicle-aided communications system for disaster recovery. Journal of Network and Computer Applications, 41(??):27–36. Elsevier. DOI: 10.1016/j.jnca.2013.10.002. After natural disasters such as earthquakes, floods, hurricanes, tornados and fires, providing emergency management schemes which mainly rely on communications systems is essential for rescue operations. To establish an emergency communications system during unforeseen events such as natural disasters, we propose the use of a team of unmanned aerial vehicles (UAVs). The proposed system is a post-disaster solution and can be used whenever and wherever required. Each UAV in the team has an onboard computer which runs three main subsystems responsible for end-to-end communication, formation control and autonomous navigation. The onboard computer and the low-level controller of the UAV cooperate to accomplish the objective of providing local communications infrastructure. In this study, the subsystems running on each UAV are explained and evaluated by simulation studies and field tests using an autonomous helicopter. While the simulation studies address the efficiency of the end-to-end communication subsystem, the field tests evaluate the accuracy of the navigation subsystem. The results of the field tests and the simulation studies show that the proposed system can be successfully used in case of disasters to establish an emergency communications system. 2013 [461] Patrick Doherty and Andrzej Szalas. 2013. Automated Generation of Logical Constraints on Approximation Spaces Using Quantifier Elimination. Fundamenta Informaticae, 127(1-4):135–149. IOS Press. DOI: 10.3233/FI-2013-900. This paper focuses on approximate reasoning based on the use of approximation spaces. Approximation spaces and the approximated relations induced by them are a generalization of the rough set-based approximations of Pawlak. Approximation spaces are used to define neighborhoods around individuals and rough inclusion functions. These in turn are used to define approximate sets and relations. In any of the approaches, one would like to embed such relations in an appropriate logical theory which can be used as a reasoning engine for specific applications with specific constraints. We propose a framework which permits a formal study of the relationship between properties of approximations and properties of approximation spaces. Using ideas from correspondence theory, we develop an analogous framework for approximation spaces. We also show that this framework can be strongly supported by automated techniques for quantifier elimination. [460] Linh Anh Nguyen, Thi-Bich-Loc Nguyen and Andrzej Szalas. 2013. HornDL: An Expressive Horn Description Logic with PTime Data Complexity. In Wolfgang Faber, Domenico Lembo, editors, Web Reasoning and Rule Systems, pages 259–264. In series: Lecture Notes in Computer Science #7994. Springer Berlin/Heidelberg. ISBN: 978-3-642-39665-6, 978-3-642-39666-3. DOI: 10.1007/978-3-642-39666-3_25. We introduce a Horn description logic called Horn-DL, which is strictly and essentially richer than Horn- SROIQ , while still has PTime data complexity. In comparison with Horn- SROIQ , HornDL additionally allows the universal role and assertions of the form irreflexive (s), ¬s(a,b) , a≐̸b . More importantly, in contrast to all the well-known Horn fragments EL , DL-Lite, DLP, Horn- SHIQ , Horn- SROIQ of description logics, HornDL allows a form of the concept constructor “universal restriction” to appear at the left hand side of terminological inclusion axioms. Namely, a universal restriction can be used in such places in conjunction with the corresponding existential restriction. In the long version of this paper, we present the first algorithm with PTime data complexity for checking satisfiability of HornDL knowledge bases. [459] Barbara Dunin-Keplicz, Linh Anh Nguyen and Andrzej Szalas. 2013. Horn-TeamLog: A Horn Fragment of TeamLog with PTime Data Complexity. In Costin Bǎdicǎ, Ngoc Thanh Nguyen, Marius Brezovan, editors, Computational Collective Intelligence. Technologies and Applications, pages 143–153. In series: Lecture Notes in Computer Science #8083. Springer Berlin/Heidelberg. ISBN: 978-3-642-40494-8, 978-3-642-40495-5. DOI: 10.1007/978-3-642-40495-5_15. The logic TeamLog proposed by Dunin-Kęplicz and Verbrugge is used to express properties of agents’ cooperation in terms of individual, bilateral and collective informational and motivational attitudes like beliefs, goals and intentions. In this paper we isolate a Horn fragment of TeamLog, called Horn-TeamLog, and we show that it has PTime data complexity. [458] Linh Anh Nguyen and Andrzej Szalas. 2013. On the Horn Fragments of Serial Regular Grammar Logics with Converse. In Dariusz Barbucha, Manh Thanh Le, Robert J. Howlett, Lakhmi C. Jain, editors, Advanced Methods and Technologies for Agent and Multi-Agent Systems: Proceedings of the 7th KES Conference on Agent and Multi-Agent Systems - Technologies and Applications (KES-AMSTA 2013), pages 225–234. In series: Frontiers in Artificial Intelligence and Applications #252. IOS Press. ISBN: 978-1-61499-253-0. DOI: 10.3233/978-1-61499-254-7-225. We study Horn fragments of serial multimodal logics which are characterized by regular grammars with converse. Such logics are useful for reasoning about epistemic states of multiagent systems as well as similarity-based approximate reasoning. We provide the first algorithm with PTIME data complexity for checking satisfiability of a Horn knowledge base in a serial regular grammar logic with converse. [457] Jan Maluszynski and Andrzej Szalas. 2013. Partiality and Inconsistency in Agents' Belief Bases. In Dariusz Barbucha, Manh Thanh Le, Robert J. Howlett, Lakhmi C. Jain, editors, Advanced Methods and Technologies for Agent and Multi-Agent Systems: Proceedings of the 7th KES Conference on Agent and Multi-Agent Systems - Technologies and Applications (KES-AMSTA 2013), pages 3–17. In series: Frontiers in Artificial Intelligence and Applications #252. IOS Press. ISBN: 978-1-61499-253-0. DOI: 10.3233/978-1-61499-254-7-3. Agents' beliefs can be incomplete and partially inconsistent. The process of agents' belief formation in such contexts has to be supported by suitable tools allowing one to express a variety of inconsistency resolving and nonmonotonic reasoning techniques.In this paper we discuss 4QL*, a general purpose rule-based query language allowing one to use rules with negation in the premises and in the conclusions of rules. It is based on a simple and intuitive semantics and provides uniform tools for lightweight versions of well-known forms of nonmonotonic reasoning. In addition, it is tractable w.r.t. data complexity and captures PTIME queries, so can be used in real-world applications.Reasoning in 4QL* is based on well-supported models. We simplify and at the same time generalize previous definitions of well-supported models and develop a new algorithm for computing such models. [456] Barbara Dunin-Keplicz, Alina Strachocka, Andrzej Szalas and Rineke Verbrugge. 2013. Perceiving Speech Acts under Incomplete and Inconsistent Information. In Dariusz Barbucha, Manh Thanh Le, Robert J. Howlett, Lakhmi C. Jain, editors, Advanced Methods and Technologies for Agent and Multi-Agent Systems: Proceedings of the 7th KES Conference on Agent and Multi-Agent Systems - Technologies and Applications (KES-AMSTA 2013), pages 255–264. In series: Frontiers in Artificial Intelligence and Applications #252. IOS Press. ISBN: 978-1-61499-253-0. DOI: 10.3233/978-1-61499-254-7-255. This paper discusses an implementation of four speech acts: assert, concede, request and challenge in a paraconsistent framework. A natural four-valued model of interaction yields multiple new cognitive situations. They are analyzed in the context of communicative relations, which partially replace the concept of trust. These assumptions naturally lead to six types of situations, which often require performing conflict resolution and belief revision.The particular choice of a rule-based, DATALOG$^{\neg \neg}$-like query language 4QL as a four-valued implementation framework ensures that, in contrast to the standard two-valued approaches, tractability of the model is achieved. [455] Barbara Dunin-Keplicz and Andrzej Szalas. 2013. Taming Complex Beliefs. In Ngoc Thanh Nguyen, editor, Transactions on Computational Collective Intelligence XI, pages 1–21. In series: Lecture Notes in Computer Science #8065. Springer Berlin/Heidelberg. ISBN: 978-3-642-41775-7, 978-3-642-41776-4. DOI: 10.1007/978-3-642-41776-4_1. A novel formalization of beliefs in multiagent systems has recently been proposed by Dunin-Kęplicz and Szałas. The aim has been to bridge the gap between idealized logical approaches to modeling beliefs and their actual implementations. Therefore the stages of belief acquisition, intermediate reasoning and final belief formation have been isolated and analyzed. In conclusion, a novel semantics reflecting those stages has been provided. This semantics is based on the new concept of epistemic profile, reflecting agent’s reasoning capabilities in a dynamic and unpredictable environment. The presented approach appears suitable for building complex belief structures in the context of incomplete and/or inconsistent information. One of original ideas is that of epistemic profiles serving as a tool for transforming preliminary beliefs into final ones. As epistemic profile can be devised both on an individual and a group level in analogical manner, a uniform treatment of single agent and group beliefs has been achieved.In the current paper these concepts are further elaborated. Importantly, we indicate an implementation framework ensuring tractability of reasoning about beliefs, propose the underlying methodology and illustrate it on an example. [454] Patrick Doherty, Fredrik Heintz and Jonas Kvarnstrm. 2013. Robotics, Temporal Logic and Stream Reasoning. In Proceedings of Logic for Programming Artificial Intelligence and Reasoning (LPAR), 2013. [453] Fredrik Heintz and Inger Erlander Klein. 2013. Civilingenjr i Mjukvaruteknik vid Linkpings universitet: ml, design och erfarenheter. In S. Vikström, R. Andersson, F. Georgsson, S. Gunnarsson, J. Malmqvist, S. Pålsson och D. Raudberget, editors, Proceedings of 4:de Utvecklingskonferensen fr Sveriges ingenjrsutbildningar (UtvSvIng). In series: UMINF #13:21. Hösten 2013 startade Linköpings universitet den första civilingenjörsutbildningen i Mjukvaruteknik. Utbildningens mål är att bland annat att ge ett helhetsperspektiv på modern storskalig mjukvaruutveckling, ge en gedigen grund i datavetenskap och computational thinking samt främja entreprenörskap och innovation. Studenternas gensvar har varit över förväntan med över 600 sökande till de 30 platserna varav 134 förstahandssökande. Här presenterar vi programmets vision, mål, designprinciper samt det färdiga programmet. En viktig förebild är ACM/IEEE Computer Science Curricula som precis kommit i en ny uppdaterad version. Tre pedagogiska idéer vi har följt är (1) att använda projektkurser för att integrera teori och praktik samt ge erfarenhet i den vanligaste arbetsformen i näringslivet; (2) att undervisa i flera olika programspråk och flera olika programutvecklingsmetodiker för att ge en plattform att ta till sig det senaste på området; och (3) att införa en programsammanhållande kurs i ingenjörsprofessionalism i årskurs 1–3 som ger studenterna verktyg att reflektera över sitt eget lärande, att jobba i näringslivet samt sin professionella yrkesroll. Artikeln avslutas med en diskussion om viktiga aspekter som computational thinking och ACM/IEEE CS Curricula. [452] Fredrik Heintz and Tommy Frnqvist. 2013. terkoppling genom automatrttning. In Proceedings of 4:de Utvecklingskonferensen fr Sveriges ingenjrsutbildningar (UtvSvIng). fulltext:postprint: http://liu.diva-portal.org/smash/get/div... Vi har undersökt olika former av återkoppling genom automaträttning i en kurs i datastrukturer och algoritmer. 2011 undersökte vi effekterna av tävlingsliknande moment som också använder automaträttning. 2012 införde vi automaträttning av laborationerna. Vi undersökte då hur återkoppling genom automaträttning påverkar studenternasarbetssätt, prestationsgrad och relation till den examinerande personalen. Genom automaträttning får studenterna omedelbar återkoppling om deras program är tillräckligt snabbt och ger rätt svar på testdata. När programmet är korrekt och resurseffektivt kontrollerar kursassistenterna att programmet även uppfyller andra krav som att vara välskrivet och välstrukturerat. Efter kursen undersökte vi studenternas inställning till och upplevelse av automaträttning genom en enkät. Resultaten är att studenterna är positiva till automaträttning (80% av alla som svarade) och att den påverkade studenternas sätt att arbeta huvudsakligen positivt. Till exempel svarade 50% att de ansträngde sig hårdare tack vare automaträttningen. Dessutom blir rättningen mer objektiv då den görs på exakt samma sätt för alla. Vår slutsats är att återkoppling genom automaträttning ger positiva effekter och upplevs som positiv av studenterna. [451] Patrick Doherty and Andrzej Szalas. 2013. Automated Generation of Logical Constraints on Approximation Spaces Using Quantifier Elimination. Fundamenta Informaticae, 127(1-4):135–149. IOS Press. DOI: 10.3233/FI-2013-900. Note: Funding Agencies|Swedish Research Council (VR) Linnaeus Center CADICS||ELLIIT Excellence Center at Linkoping-Lund in Information Technology||CUAS project||SSF, the Swedish Foundation for Strategic Research|| This paper focuses on approximate reasoning based on the use of approximation spaces. Approximation spaces and the approximated relations induced by them are a generalization of the rough set-based approximations of Pawlak. Approximation spaces are used to define neighborhoods around individuals and rough inclusion functions. These in turn are used to define approximate sets and relations. In any of the approaches, one would like to embed such relations in an appropriate logical theory which can be used as a reasoning engine for specific applications with specific constraints. We propose a framework which permits a formal study of the relationship between properties of approximations and properties of approximation spaces. Using ideas from correspondence theory, we develop an analogous framework for approximation spaces. We also show that this framework can be strongly supported by automated techniques for quantifier elimination. [450] Robin Murphy and Alexander Kleiner. 2013. A Community-Driven Roadmap for the Adoption of Safety Security and Rescue Robots. In Safety, Security, and Rescue Robotics (SSRR), 2013 IEEE International Symposium on, pages 1–5. IEEE conference proceedings. ISBN: 978-1-4799-0879-0. DOI: 10.1109/SSRR.2013.6719375. Note: Accepted for Publication. fulltext:postprint: http://liu.diva-portal.org/smash/get/div... The IEEE Safety, Security, and Rescue Robotics community has created a roadmap for producing unmanned systems that could be adopted by the Public Safety sector within 10 years, given appropriate R&D investment especially in human-robot interaction and perception. The five applications expected to be of highest value to the Public Safety community, highest value first, are: assisting with routine inspection of the critical infrastructure, “chronic emergencies” such as firefighting, hazardous material spills, port inspection, and damage estimation after a disaster. The technical feasibility of the applications were ranked, with the most attractive scenario, infrastructure inspection, rated as the second easiest scenario; this suggests the maturity of robotics technology is beginning to match stakeholder needs. Each of the five applications were discussed in terms of the six broad enabling technology areas specified in the current National Robotics Initiative Roadmap (perception, human-robot interaction, mechanisms, modeling and simulation, control and planning, and testing and evaluation) and nine specific capabilities identified by the community as being essential to commercialization (communication, alerting, localization, fault tolerance, mapping, manpower needs, plug and play capabilities, multiple users, and multiple robots). The community believes that perception and human-robot interaction are the two biggest barriers to adoption, and require more research, given that their low technical maturity (3rd and 6th rank respectively). However, each of the specific capabilities needed for commercialization are being addressed by current research and could be achieved within 10 years with sustained funding. [449] Jakob Pogulis. 2013. Testramverk fr distribuerade system. Student Thesis. 46 pages. ISRN: LIU-IDA/LITH-EX-G--13/010--SE. When developing software that is meant to be distributed over several different computers and several different networks while still working together against a common goal there is a challenge in testing how updates within a single component will affect the system as a whole. Even if the performance of that specific component increases that is no guarantee for the increased performance of the entire system. Traditional methods of testing software becomes both hard and tedious when several different machines has to be involved for a single test and all of those machines has to be synchronized as well.This thesis has resulted in an exemplary application suite for testing distributed software. The thesis describes the method used for implementation as well as a description of the actual application suite that was developed. During the development several important factors and improvements for such a system was identified, which are described at the end of the thesis even though some of them never made it into the actual implementation. The implemented application suite could be used as a base when developing a more complete system in order to distribute tests and applications that has to run in a synchronized manner with the ability to report the results of each individual component. [448] Christian Dornhege, Alexander Kleiner and Andreas Kolling. 2013. Coverage Search in 3D. In Safety, Security, and Rescue Robotics (SSRR), 2013 IEEE International Symposium on, pages 1–8. IEEE. ISBN: 978-1-4799-0879-0. DOI: 10.1109/SSRR.2013.6719340. Note: Accepted for Publication. fulltext:postprint: http://liu.diva-portal.org/smash/get/div... Searching with a sensor for objects and to observe parts of a known environment efficiently is a fundamental prob- lem in many real-world robotic applications such as household robots searching for objects, inspection robots searching for leaking pipelines, and rescue robots searching for survivors after a disaster. We consider the problem of identifying and planning efficient view point sequences for covering complex 3d environments. We compare empirically several variants of our algorithm that allow to trade-off schedule computation against execution time. Our results demonstrate that, despite the intractability of the overall problem, computing effective solutions for coverage search in real 3d environments is feasible. [447] Andrzej Szalas. 2013. How an agent might think. Logic journal of the IGPL (Print), 21(3):515–535. Oxford University Press (OUP): Policy A - Oxford Open Option A. DOI: 10.1093/jigpal/jzs051. The current article is devoted to extensions of the rule query language 4QL proposed by Małuszyński and Szałas. 4QL is a Datalog¬¬-like language, allowing one to use rules with negation in heads and bodies of rules. It is based on a simple and intuitive semantics and provides uniform tools for lightweight versions of well-known forms of non-monotonic reasoning. In addition, 4QL is tractable w.r.t. data complexity and captures PTime queries. In the current article we relax most of restrictions of 4QL, obtaining a powerful but still tractable query language 4QL+. In its development we mainly focused on its pragmatic aspects: simplicity, tractability and generality. In the article we discuss our approach and choices made, define a new, more general semantics and investigate properties of 4QL+. [446] Fredrik Heintz. 2013. Semantically Grounded Stream Reasoning Integrated with ROS. In Proceedings of the IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), pages 5935–5942. In series: IEEE International Conference on Intelligent Robots and Systems. Proceedings #??. IEEE conference proceedings. ISBN: 978-146736358-7. DOI: 10.1109/IROS.2013.6697217. fulltext:postprint: http://liu.diva-portal.org/smash/get/div... High level reasoning is becoming essential to autonomous systems such as robots. Both the information available to and the reasoning required for such autonomous systems is fundamentally incremental in nature. A stream is a flow of incrementally available information and reasoning over streams is called stream reasoning. Incremental reasoning over streaming information is necessary to support a number of important robotics functionalities such as situation awareness, execution monitoring, and decision making.This paper presents a practical framework for semantically grounded temporal stream reasoning called DyKnow. Incremental reasoning over streams is achieved through efficient progression of temporal logical formulas. The reasoning is semantically grounded through a common ontology and a specification of the semantic content of streams relative to the ontology. This allows the finding of relevant streams through semantic matching. By using semantic mappings between ontologies it is also possible to do semantic matching over multiple ontologies. The complete stream reasoning framework is integrated in the Robot Operating System (ROS) thereby extending it with a stream reasoning capability. [445] Gianpaolo Conte, Alexander Kleiner, Piotr Rudol, Karol Korwel, Mariusz Wzorek and Patrick Doherty. 2013. Performance evaluation of a light weight multi-echo LIDAR for unmanned rotorcraft applications. In International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XL-1/W2. In series: International Archives of Photogrammetry, Remote Sensing and Spatial Information Sciences #??. The paper presents a light-weight and low-cost airborne terrain mapping system. The developed Airborne LiDAR Scanner (ALS) sys- tem consists of a high-precision GNSS receiver, an inertial measurement unit and a magnetic compass which are used to complement a LiDAR sensor in order to compute the terrain model. Evaluation of the accuracy of the generated 3D model is presented. Additionally, a comparison is provided between the terrain model generated from the developed ALS system and a model generated using a commer- cial photogrammetric software. Finally, the multi-echo capability of the used LiDAR sensor is evaluated in areas covered with dense vegetation. The ALS system and camera systems were mounted on-board an industrial unmanned helicopter of around 100 kilograms maximum take-off weight. Presented results are based on real flight-test data. [444] Andreas Kolling, Alexander Kleiner and Piotr Rudol. 2013. Fast Guaranteed Search With Unmanned Aerial Vehicles. In Proc. of the IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2013), pages 6013–6018. In series: IEEE International Conference on Intelligent Robots and Systems. Proceedings #??. IEEE. DOI: 10.1109/IROS.2013.6697229. In this paper we consider the problem of searching for an arbitrarily smart and fast evader in a large environment with a team of unmanned aerial vehicles (UAVs) while providing guarantees of detection. Our emphasis is on the fast execution of efficient search strategies that minimize the number of UAVs and the search time. We present the first approach for computing fast search strategies utilizing additional searchers to speed up the execution time and thereby enabling large scale UAV search. In order to scale to very large environments when using UAVs one would either have to overcome the energy limitations of UAVs or pay the cost of utilizing additional UAVs to speed up the search. Our approach is based on coordinating UAVs on sweep lines, covered by the UAV sensors, that move simultaneously through an environment. We present some simulation results that show a significant reduction in execution time when using multiple UAVs and a demonstration of a real system with three ARDrones. [443] Karen Petersen, Alexander Kleiner and Oskar von Stryk. 2013. Fast Task-Sequence Allocation for Heterogeneous Robot Teams with a Human in the Loop. In Proc. of the IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2013), pages 1648–1655. In series: IEEE International Conference on Intelligent Robots and Systems. Proceedings #??. IEEE. DOI: 10.1109/IROS.2013.6696570. Efficient task allocation with timing constraints to a team of possibly heterogeneous robots is a challenging problem with application, e.g., in search and rescue. In this paper a mixed-integer linear programming (MILP) approach is proposed for assigning heterogeneous robot teams to the simultaneous completion of sequences of tasks with specific requirements such as completion deadlines. For this purpose our approach efficiently combines the strength of state of the art Mixed Integer Linear Programming (MILP) solvers with human expertise in mission scheduling. We experimentally show that simple and intuitive inputs by a human user have substantial impact on both computation time and quality of the solution. The presented approach can in principle be applied to quite general missions for robot teams with human supervision. [442] Christopher Bergdahl. 2013. Modeling Air Combat with Influence Diagrams. Student Thesis. 64 pages. ISRN: LIU-IDA/LITH-EX-A--13/031--SE. Air combat is a complex situation, training for it and analysis of possible tactics are time consuming and expensive. In order to circumvent those problems, mathematical models of air combat can be used. This thesis presents air combat as a one-on-one influence diagram game where the influence diagram allows the dynamics of the aircraft, the preferences of the pilots and the uncertainty of decision making in a structural and transparent way to be taken into account. To obtain the players’ game optimal control sequence with respect to their preferences, the influence diagram has to be solved. This is done by truncating the diagram with a moving horizon technique and determining and implementing the optimal controls for a dynamic game which only lasts a few time steps.The result is a working air combat model, where a player estimates the probability that it resides in any of four possible states. The pilot’s preferences are modeled by utility functions, one for each possible state. In each time step, the players are maximizing the cumulative sum of the utilities for each state which each possible action gives. These are weighted with the corresponding probabilities. The model is demonstrated and evaluated in a few interesting aspects. The presented model offers a way of analyzing air combat tactics and maneuvering as well as a way of making autonomous decisions in for example air combat simulators. [441] Johan Fredborg. 2013. Spam filter for SMS-traffic. Student Thesis. 82 pages. ISRN: LIU-IDA/LITH-EX-A--13/021-SE. Communication through text messaging, SMS (Short Message Service), is nowadays a huge industry with billions of active users. Because of the huge userbase it has attracted many companies trying to market themselves through unsolicited messages in this medium in the same way as was previously done through email. This is such a common phenomenon that SMS spam has now become a plague in many countries.This report evaluates several established machine learning algorithms to see how well they can be applied to the problem of filtering unsolicited SMS messages. Each filter is mainly evaluated by analyzing the accuracy of the filters on stored message data. The report also discusses and compares requirements for hardware versus performance measured by how many messages that can be evaluated in a fixed amount of time.The results from the evaluation shows that a decision tree filter is the best choice of the filters evaluated. It has the highest accuracy as well as a high enough process rate of messages to be applicable. The decision tree filter which was found to be the most suitable for the task in this environment has been implemented. The accuracy in this new implementation is shown to be as high as the implementation used for the evaluation of this filter.Though the decision tree filter is shown to be the best choice of the filters evaluated it turned out the accuracy is not high enough to meet the specified requirements. It however shows promising results for further testing in this area by using improved methods on the best performing algorithms. [440] Fredrik Heintz and Daniel de Leng. 2013. Semantic Information Integration with Transformations for Stream Reasoning. In 16th International Conference on Information Fusion, pages 445–452. IEEE. ISBN: 978-605-86311-1-3. fulltext:postprint: http://liu.diva-portal.org/smash/get/div... The automatic, on-demand, integration of information from multiple diverse sources outside the control of the application itself is central to many fusion applications. An important problem is to handle situations when the requested information is not directly available but has to be generated or adapted through transformations. This paper extends the semantic information integration approach used in the stream-based knowledge processing middleware DyKnow with support for finding and automatically applying transformations. Two types of transformations are considered. Automatic transformation between different units of measurements and between streams of different types. DyKnow achieves semantic integration by creating a common ontology, specifying the semantic content of streams relative to the ontology and using semantic matching to find relevant streams. By using semantic mappings between ontologies it is also possible to do semantic matching over multiple ontologies. The complete stream reasoning approach is integrated in the Robot Operating System (ROS) and used in collaborative unmanned aircraft systems missions. [439] Mikael Nilsson. 2013. On the Complexity of Finding Spanner Paths. In Sandor P. Fekete, editor, Booklet of Abstracts, The European Workshop on Computational Geometry (EuroCG), pages 77–80. Booklet of Abstracts: http://www.ibr.cs.tu-bs.de/alg/eurocg13/... fulltext:print: http://liu.diva-portal.org/smash/get/div... We study the complexity of finding so called spanner paths between arbitrary nodes in Euclidean graphs. We study both general Euclidean graphs and a special type of graphs called Integer Graphs. The problem is proven NP-complete for general Euclidean graphs with non-constant stretches (e.g. (2n)^(3/2) where n denotes the number of nodes in the graph). An algorithm solving the problem in O(2^(0.822n)) is presented. Integer graphs are simpler and for these special cases a better algorithm is presented. By using a partial order of so called Images the algorithm solves the spanner path problem using O(2^(c(\log n)^2)) time, where c is a constant depending only on the stretch. [438] Cyrille Berger. 2013. Toward rich geometric map for SLAM: online detection of planets in 2D LIDAR. Journal of Automation, Mobile Robotics & Intelligent Systems, 7(1):35–41. Link to article: http://www.jamris.org/archive.php Rich geometric models of the environment are needed for robots to carry out their missions. However a robot operating in a large environment would require a compact representation. In this article, we present a method that relies on the idea that a plane appears as a line segment in a 2D scan, and that by tracking those lines frame after frame, it is possible to estimate the parameters of that plane. The method is divided in three steps: fitting line segments on the points of the 2D scan, tracking those line segments in consecutive scan and estimating the parameters with a graph based SLAM (Simultaneous Localisation And Mapping) algorithm. [437] Patrick Doherty, Fredrik Heintz and Jonas Kvarnstrm. 2013. High-level Mission Specification and Planning for Collaborative Unmanned Aircraft Systems using Delegation. Unmanned Systems, 1(1):75–119. World Scientific. DOI: 10.1142/S2301385013500052. Automated specification, generation and execution of high level missions involving one or more heterogeneous unmanned aircraft systems is in its infancy. Much previous effort has been focused on the development of air vehicle platforms themselves together with the avionics and sensor subsystems that implement basic navigational skills. In order to increase the degree of autonomy in such systems so they can successfully participate in more complex mission scenarios such as those considered in emergency rescue that also include ongoing interactions with human operators, new architectural components and functionalities will be required to aid not only human operators in mission planning, but also the unmanned aircraft systems themselves in the automatic generation, execution and partial verification of mission plans to achieve mission goals. This article proposes a formal framework and architecture based on the unifying concept of delegation that can be used for the automated specification, generation and execution of high-level collaborative missions involving one or more air vehicles platforms and human operators. We describe an agent-based software architecture, a temporal logic based mission specification language, a distributed temporal planner and a task specification language that when integrated provide a basis for the generation, instantiation and execution of complex collaborative missions on heterogeneous air vehicle systems. A prototype of the framework is operational in a number of autonomous unmanned aircraft systems developed in our research lab. [436] Fredrik Heintz, Jonas Kvarnstrm and Patrick Doherty. 2013. Stream-Based Hierarchical Anchoring. Knstliche Intelligenz, 27(2):119–128. Springer. DOI: 10.1007/s13218-013-0239-2. Autonomous systems situated in the real world often need to recognize, track, and reason about various types of physical objects. In order to allow reasoning at a symbolic level, one must create and continuously maintain a correlation between symbols denoting physical objects and sensor data being collected about them, a process called anchoring.In this paper we present a stream-based hierarchical anchoring framework. A classification hierarchy is associated with expressive conditions for hypothesizing the type and identity of an object given streams of temporally tagged sensor data. The anchoring process constructs and maintains a set of object linkage structures representing the best possible hypotheses at any time. Each hypothesis can be incrementally generalized or narrowed down as new sensor data arrives. Symbols can be associated with an object at any level of classification, permitting symbolic reasoning on different levels of abstraction. The approach is integrated in the DyKnow knowledge processing middleware and has been applied to an unmanned aerial vehicle traffic monitoring application. [435] Hkan Warnquist, Jonas Kvarnstrm and Patrick Doherty. 2013. Exploiting Fully Observable and Deterministic Structures in Goal POMDPs. In Daniel Borrajo, Subbarao Kambhampati, Angelo Oddi, Simone Fratini, editors, Proceedings of the 23rd International Conference on Automated Planning and Scheduling (ICAPS), pages 242–250. AAAI Press. ISBN: 978-1-57735-609-7. Link to full text: http://www.aaai.org/ocs/index.php/ICAPS/... When parts of the states in a goal POMDP are fully observable and some actions are deterministic it is possibleto take advantage of these properties to efficiently generate approximate solutions. Actions that deterministically affect the fully observable component of the world state can be abstracted away and combined into macro actions, permitting a planner to converge more quickly. This processing can be separated from the main search procedure, allowing us to leverage existing POMDP solvers. Theoretical results show how a POMDP can be analyzed to identify the exploitable properties and formal guarantees are provided showing that the use of macro actions preserves solvability. The efficiency of the method is demonstrated with examples when used in combination with existing POMDP solvers. [434] Mikael Nilsson, Jonas Kvarnstrm and Patrick Doherty. 2013. Incremental Dynamic Controllability Revisited. In Proceedings of the 23rd International Conference on Automated Planning and Scheduling (ICAPS). AAAI Press. ISBN: 978-1-57735-609-7. Simple Temporal Networks with Uncertainty (STNUs) allow the representation of temporal problems where some durations are determined by nature, as is often the case for actions in planning. As such networks are generated it is essential to verify that they are dynamically controllable – executable regardless of the outcomes of uncontrollable durations – and to convert them to a dispatchable form. The previously published FastIDC algorithm achieves this incrementally and can therefore be used efficiently during plan construction. In this paper we show that FastIDC is not sound when new constraints are added, sometimes labeling networks as dynamically controllable when they are not. We analyze the algorithm, pinpoint the cause, and show how the algorithm can be modified to correctly detect uncontrollable networks. [433] Andreas Kolling and Alexander Kleiner. 2013. Multi-UAV Trajectory Planning for Guaranteed Search. In Proc. of the 12th Int. Conf. on Autonomous Agents and Multiagent Systems (AAMAS 2013), pages 79–86. ISBN: 978-1-4503-1993-5. fulltext:preprint: http://liu.diva-portal.org/smash/get/div... We consider the problem of detecting all moving and evading targets in 2.5D environments with teams of UAVs. Targets are assumed to be fast and omniscient while UAVs are only equipped with limited range detection sensors and have no prior knowledge about the location of targets. We present an algorithm that, given an elevation map of the environment, computes synchronized trajectories for the UAVs to guarantee the detection of all targets. The approach is based on coordinating the motion of multiple UAVs on sweep lines to clear the environment from contamination, which represents the possibility of an undetected target being located in an area. The goal is to compute trajectories that minimize the number of UAVs needed to execute the guaranteed search. This is achieved by converting 2D strategies, computed for a polygonal representation of the environment, to 2.5D strategies. We present methods for this conversion and consider cost of motion and visibility constraints. Experimental results demonstrate feasibility and scalability of the approach. Experiments are carried out on real and artificial elevation maps and provide the basis for future deployments of large teams of real UAVs for guaranteed search. [432] Alexander Kleiner, A. Farinelli, S. Ramchurn, B. Shi, F. Maffioletti and R. Reffato. 2013. RMASBench: Benchmarking Dynamic Multi-Agent Coordination in Urban Search and Rescue. In Proc. of the 12th Int. Conf. on Autonomous Agents and Multiagent Systems (AAMAS 2013), pages 1195–1196. ISBN: 978-1-4503-1993-5. fulltext:preprint: http://liu.diva-portal.org/smash/get/div... We propose RMASBench, a new benchmarking tool based on the RoboCup Rescue Agent simulation system, to easily compare coordination approaches in a dynamic rescue scenario. In particular, we offer simple interfaces to plug-in coordination algorithms without the need for implementing and tuning low-level agents behaviors. Moreover, we add to the realism of the simulation by providing a large scale crowd simulator, which exploits GPUs parallel architecture, to simulate the behavior of thousands of agents in real time. Finally, we focus on a specific coordination problem where fire fighters must combat fires and prevent them from spreading across the city. We formalize this problem as a Distributed Constraint Optimization Problem and we compare two state-of-the art solution techniques: DSA and MaxSum. We perform an extensive empirical evaluation of such techniques considering several standard measures for performance (e.g. damages to buildings) and coordination overhead (e.g., message exchanged and non concurrent constraint checks). Our results provide interesting insights on limitations and benefits of DSA and MaxSum in our rescue scenario and demonstrate that RMASBench offers powerful tools to compare coordination algorithms in a dynamic environment. [431] H. Levent Akin, Nobuhiro Ito, Adam Jacoff, Alexander Kleiner, Johannes Pellenz and Arnoud Visser. 2013. RoboCup Rescue Robot and Simulation Leagues. The AI Magazine, 34(1):??–??. AAAI Press. Link to journal: http://www.aaai.org/ojs/index.php/aimaga... The RoboCup Rescue Robot and Simulation competitions have been held since 2000. The experience gained during these competitions has increased the maturity level of the field, which allowed deploying robots after real disasters (e.g. Fukushima Daiichi nuclear disaster). This article provides an overview of these competitions and highlights the state of the art and the lessons learned. [430] Alexander Kleiner and Andreas Kolling. 2013. Guaranteed Search With Large Teams of Unmanned Aerial Vehicles. In Proc. of the IEEE Int. Conf. on Robotics and Automation (ICRA), pages 2977–2983. In series: Robotics and Automation (ICRA), 2013 IEEE International Conference on #??. IEEE conference proceedings. ISBN: 978-1-4673-5641-1. DOI: 10.1109/ICRA.2013.6630990. We consider the problem of detecting moving and evading targets by a team of coordinated unmanned aerial vehicles (UAVs) in large and complex 2D and 2.5D environments. Our approach is based on the coordination of 2D sweep lines that move through the environment to clear it from all contamination, representing the possibility of a target being located in an area, and thereby detecting all targets. The trajectories of the UAVs are implicitly given by the motion of these sweep lines and their costs are determined by the number of UAVs needed. A novel algorithm that computes low cost coordination strategies of the UAV sweep lines in simply connected polygonal environments is presented. The resulting strategies are then converted to strategies clearing multiply connected and 2.5D environments. Experiments on real and artificial elevation maps with complex visibility constraints are presented and demonstrate the feasibility and scalability of the approach. The algorithms used for the experiments are made available on a public repository. [429] Quirin Hamp, Omar Gorgis, Patrick Labenda, Marc Neumann, Thomas Predki, Leif Heckes, Alexander Kleiner and Leonard Reindl. 2013. Study of efficiency of USAR operations with assistive technologies. Advanced Robotics, 27(5):337–350. DOI: 10.1080/01691864.2013.763723. Note: Funding Agencies|German Federal Ministry of Education and Research|13N9759|German Federal Agency for Technical Relief (THW)||RIF e.V.||JT-electronic GmbH||carat robotic innovation GmbH||Berlin- Oberspree Sondermaschinenbau GmbH (BOS)||SEEBA|| This paper presents presents a study on eciency of Urban Search and Rescue (USAR) missions that has been carried out within the framework of the German research project I-LOV. After three years of development, first field tests have been carried out in 2011 by professionals such as the Rapid Deployment Unit for Salvage Operations Abroad (SEEBA). We present results from evaluating search teams in simulated USAR scenarios equipped with newly developed technical search means and digital data input terminals developed in the I-LOV project. In particular, USAR missions assisted by the “bioradar”, a ground-penetrating radar system for the detection of humanoid movements, a semi-active video probe of more than 10 m length for rubble pile exploration, a snake-like rescue robot, and the decision support system FRIEDAA were evaluated and compared with conventional USAR missions. Results of this evaluation indicate that the developed technologies represent an advantages for USAR missions, which are discussed in this paper. [428] Linh Anh Nguyen and Andrzej Szalas. 2013. Logic-Based Roughification. In Andrzej Skowron, Zbigniew Suraj, editors, Rough Sets and Intelligent Systems - Professor Zdzis?aw Pawlak in Memoriam (vol. I), pages 517–543. In series: Intelligent Systems Reference Library #42. Springer Berlin/Heidelberg. ISBN: 978-3-642-30343-2. DOI: 10.1007/978-3-642-30344-9_19. find book at a swedish library/hitta boken i ett svenskt bibliotek: http://libris.kb.se/bib/13601690 find book in another country/hitta boken i ett annat land: http://www.worldcat.org/title/rough-sets... This book is dedicated to the memory of Professor Zdzis{\l}aw Pawlak who passed away almost six year ago. He is the founder of the Polish school of Artificial Intelligence and one of the pioneers in Computer Engineering and Computer Science with worldwide influence. He was a truly great scientist, researcher, teacher and a human being.This book prepared in two volumes contains more than 50 chapters. This demonstrates that the scientific approaches discovered by of Professor Zdzis{\l}aw Pawlak, especially the rough set approach as a tool for dealing with imperfect knowledge, are vivid and intensively explored by many researchers in many places throughout the world. The submitted papers prove that interest in rough set research is growing and is possible to see many new excellent results both on theoretical foundations and applications of rough sets alone or in combination with other approaches.We are proud to offer the readers this book. [427] Barbara Dunin-Keplicz and Andrzej Szalas. 2013. Distributed Paraconsistent Belief Fusion. In Giancarlo Fortino , Costin Badica , Michele Malgeri and Rainer Unland, editors, Intelligent Distributed Computing VI: Proceedings of the 6th International Symposium on Intelligent Distributed Computing - IDC 2012, Calabria, Italy, September 2012, pages 59–69. In series: Studies in Computational Intelligence #446. Springer Berlin/Heidelberg. ISBN: 978-3-642-32523-6, 978-3-642-32524-3. DOI: 10.1007/978-3-642-32524-3_9. find book at a swedish library/hitta boken i ett svenskt bibliotek: http://libris.kb.se/bib/13601893 The current paper is devoted to belief fusion when information sources may deliver incomplete and inconsistent information. In such cases paraconsistent and commonsense reasoning techniques can be used to complete missing knowledge and disambiguate inconsistencies. We propose a novel, realistic model of distributed belief fusion and an implementation framework guaranteeing its tractability. [426] C. Dornhege and Alexander Kleiner. 2013. A Frontier-Void-Based Approach for Autonomous Exploration in 3D. Advanced Robotics, 27(6):459–468. Taylor and Francis. DOI: 10.1080/01691864.2013.763720. Note: Funding Agencies|Deutsche Forschungsgemeinschaft in the Transregional Collaborative Research Center|SFB/TR8| We consider the problem of an autonomous robot searching for objects in unknown 3d space. Similar to the well known frontier-based exploration in 2d, the problem is to determine a minimal sequence of sensor viewpoints until the entire search space has been explored. We introduce a novel approach that combines the two concepts of voids, which are unexplored volumes in 3d, and frontiers, which are regions on the boundary between voids and explored space. Our approach has been evaluated on a mobile platform equipped with a manipulator searching for victims in a simulated USAR setup. First results indicate the real-world capability and search efficiency of the proposed method. 2012 [425] Patrick Doherty and John-Jules Ch. Meyer. 2012. On the Logic of Delegation - Relating Theory and Practice. In Fabio Paglieri, Luca Tummolini, Rino Falcone, Maria Miceli, editors, The Goals of Cognition: Essays in honour of Cristiano Castelfranchi, pages 467–496. College Publications. ISBN: 978-1848900943. Find book in another country/Hitta boken i ett annat land: http://www.worldcat.org/search?q=978-184... Research with collaborative robotic systems has much to gain by leveraging concepts and ideas from the areas of multi-agent systems and the social sciences. In this paper we propose an approach to formalizing and grounding important aspects of collaboration in a collaborative system shell for robotic systems. This is done primarily in terms of the concept of delegation, where delegation will be instantiated as a speech act. The formal characterization of the delegation speech act is based on a preformal theory of delegation proposed by Falcone and Castelfranchi. We show how the delegation speech act can in fact be used to formally ground an abstract characterization of delegation into a FIPA-compliant implementation in an agent-oriented language such as JADE, as part of a collaborative system shell for robotic systems. The collaborative system shell has been developed as a prototype and used in collaborative missions with multiple unmanned aerial vehicle systems. [424] Patrick Doherty, Fredrik Heintz and David Landn. 2012. A Distributed Task Specification Language for Mixed-Initiative Delegation. In Nirmit Desai, Alan Liu, Michael Winikoff, editors, Principles and Practice of Multi-Agent Systems: 13th International Conference, PRIMA 2010, Kolkata, India, November 12-15, 2010, Revised Selected Papers, pages 42–57. In series: Lecture Notes in Computer Science #7057. Springer Berlin/Heidelberg. ISBN: 978-3-642-25919-7, e-978-3-642-25920-3. DOI: 10.1007/978-3-642-25920-3_4. In the next decades, practically viable robotic/agent systems are going to be mixed-initiative in nature. Humans will request help from such systems and such systems will request help from humans in achieving the complex mission tasks required. Pragmatically, one requires a distributed task specification language to define tasks and a suitable data structure which satisfies the specification and can be used flexibly by collaborative multi-agent/robotic systems. This paper defines such a task specification language and an abstract data structure called Task Specification Trees which has many of the requisite properties required for mixed-initiative problem solving and adjustable autonomy in a distributed context. A prototype system has been implemented for this delegation framework and has been used practically with collaborative unmanned aircraft systems. [423] David Landn, Fredrik Heintz and Patrick Doherty. 2012. Complex Task Allocation in Mixed-Initiative Delegation: A UAV Case Study. In Nirmit Desai, Alan Liu, Michael Winikoff, editors, Principles and Practice of Multi-Agent Systems: 13th International Conference, PRIMA 2010, Kolkata, India, November 12-15, 2010, Revised Selected Papers, pages 288–303. In series: Lecture Notes in Computer Science #7057. Springer Berlin/Heidelberg. ISBN: 978-3-642-25919-7, e-978-3-642-25920-3. DOI: 10.1007/978-3-642-25920-3_20. Unmanned aircraft systems (UASs) are now becoming technologically mature enough to be integrated into civil society. An essential issue is principled mixed-initiative interaction between UASs and human operators. Two central problems are to specify the structure and requirements of complex tasks and to assign platforms to these tasks. We have previously proposed Task Specification Trees (TSTs) as a highly expressive specification language for complex multi-agent tasks that supports mixed-initiative delegation and adjustable autonomy. The main contribution of this paper is a sound and complete distributed heuristic search algorithm for allocating the individual tasks in a TST to platforms. The allocation also instantiates the parameters of the tasks such that all the constraints of the TST are satisfied. Constraints are used to model dependencies between tasks, resource usage as well as temporal and spatial requirements on complex tasks. Finally, we discuss a concrete case study with a team of unmanned aerial vehicles assisting in a challenging emergency situation. [422] Cyrille Berger. 2012. Weak Constraints Network Optimiser. In Proceedings of the IEEE International Conference on Robotics and Automation (ICRA), pages 1270–1277. IEEE. DOI: 10.1109/ICRA.2012.6225060. We present a general framework to estimate the parameters of both a robot and landmarks in 3D. It relies on the use of a stochastic gradient descent method for the optimisation of the nodes in a graph of weak constraints where the landmarks and robot poses are the nodes. Then a belief propagation method combined with covariance intersection is used to estimate the uncertainties of the nodes. The first part of the article describes what is needed to define a constraint and a node models, how those models are used to update the parameters and the uncertainties of the nodes. The second part present the models used for robot poses and interest points, as well as simulation results. [421] Gerald Steinbauer and Alexander Kleiner. 2012. Towards CSP-based mission dispatching in C2/C4I systems. In Proc. of the IEEE Int. Workshop on Safety, Security and Rescue Robotics (SSRR), pages 1–6. IEEE. ISBN: 978-1-4799-0164-7, 978-1-4799-0163-0, 978-1-4799-0165-4. DOI: 10.1109/SSRR.2012.6523875. fulltext:preprint: http://liu.diva-portal.org/smash/get/div... One challenging problem in disaster response is to efficiently assign resources such as fire fighters and trucks to local incidents that are spatially distributed on a map. Existing systems for command and control (C2/C4I) are coming with powerful interfaces enabling the manual assignment of resources to the incident commander. However, with increasing number of local incidents over time the performance of manual methods departs arbitrarily from an optimal solution. In this paper we introduce preliminary results of building an interface between existing professional C2/C4I systems and Constraint Satisfaction Problem (CSP)-solvers. We show by using an example the feasibility of scheduling and assigning missions having deadlines and resource constraints. [420] L. Marconi, C. Melchiorri, M. Beetz, D. Pangercic, R. Siegwart, S. Leutenegger, R. Carloni, S. Stramigioli, H. Bruyninckx, Patrick Doherty, Alexander Kleiner, V. Lippiello, A. Finzi, B. Siciliano, A. Sala and N. Tomatis. 2012. The SHERPA project: Smart collaboration between humans and ground-aerial robots for improving rescuing activities in alpine environments. In Proc. of the IEEE Int. Workshop on Safety, Security and Rescue Robotics (SSRR), pages 1–4. IEEE. ISBN: 978-1-4799-0164-7, 978-1-4799-0163-0, 978-1-4799-0165-4. DOI: 10.1109/SSRR.2012.6523905. The goal of the paper is to present the foreseen research activity of the European project “SHERPA” whose activities will start officially on February 1th 2013. The goal of SHERPA is to develop a mixed ground and aerial robotic platform to support search and rescue activities in a real-world hostile environment, like the alpine scenario that is specifically targeted in the project. Looking into the technological platform and the alpine rescuing scenario, we plan to address a number of research topics about cognition and control. What makes the project potentially very rich from a scientific viewpoint is the heterogeneity and the capabilities to be owned by the different actors of the SHERPA system: the human rescuer is the “busy genius”, working in team with the ground vehicle, as the “intelligent donkey”, and with the aerial platforms, i.e. the “trained wasps” and “patrolling hawks”. Indeed, the research activity focuses on how the “busy genius” and the “SHERPA animals” interact and collaborate with each other, with their own features and capabilities, toward the achievement of a common goal. [419] Luc De Raedt, Christian Bessiere, Didier Dubois, Patrick Doherty, Paolo Frasconi, Fredrik Heintz and Peter Lucas. 2012. Proceedings of the 20th European Conference on Artificial Intelligence (ECAI). Conference Proceedings. In series: Frontiers in Artificial Intelligence and Applications #242. IOS Press. 1056 pages. ISBN: 978-1-61499-097-0. [418] Jonatan Olofsson. 2012. Towards Autonomous Landing of a Quadrotorusing Monocular SLAM Techniques. Student Thesis. 102 pages. ISRN: LIU-IDA/LITH-EX-A--12/026--SE. Use of Unmanned Aerial Vehicles have seen enormous growth in recent years due to the advances in related scientific and technological fields. This fact combined with decreasing costs of using UAVs enables their use in new application areas. Many of these areas are suitable for miniature scale UAVs - Micro Air Vehicles(MAV) - which have the added advantage of portability and ease of deployment. One of the main functionalities necessary for successful MAV deployment in real-world applications is autonomous landing. Landing puts particularly high requirements on positioning accuracy, especially in indoor confined environments where the common global positioning technology is unavailable. For that reason using an additional sensor, such as a camera, is beneficial. In this thesis, a set of technologies for achieving autonomous landing is developed and evaluated. In particular, state estimation based on monocular vision SLAM techniques is fused with data from onboard sensors. This is then used as the basis for nonlinear adaptive control as well trajectory generation for a simple landing procedure. These components are connected using a new proposed framework for robotic development. The proposed system has been fully implemented and tested in a simulated environment and validated using recorded data. Basic autonomous landing was performed in simulation and the result suggests that the proposed system is a viable solution for achieving a fully autonomous landing of a quadrotor. [417] Cyrille Berger. 2012. Toward rich geometric map for SLAM: Online Detection of Planes in 2D LIDAR. In Proceedings of the International Workshop on Perception for Mobile Robots Autonomy (PEMRA). fulltext:postprint: http://liu.diva-portal.org/smash/get/div... Rich geometric models of the environment are needed for robots to accomplish their missions. However a robot operatingin a large environment would require a compact representation.In this article, we present a method that relies on the idea that a plane appears as a line segment in a 2D scan, andthat by tracking those lines frame after frame, it is possible to estimate the parameters of that plane. The method istherefore divided in three steps: fitting line segments on the points of the 2D scan, tracking those line segments inconsecutive scan and estimating the parameters with a graph based SLAM (Simultaneous Localisation And Mapping)algorithm. [416] Ha Quang-Thuy, Hoang Thi-Lan-Giao, Linh Anh Nguyen, Hung Son Nguyen, Andrzej Szalas and Tran Thanh-Luong. 2012. Concept Learning for Description Logic-based Information Systems. In KSE 2012 - International Conference on Knowledge and Systems Engineering, pages 65–73. IEEE Computer Society. DOI: 10.1109/KSE.2012.23. [415] Ha Quang-Thuy, Hoang Thi-Lan-Giao, Linh Anh Nguyen, Nguyen Hung-Son, Andrzej Szalas and Tran Thanh-Luong. 2012. A Bisimulation-based Method of Concept Learning for Knowledge Bases in Description Logics. In SoICT 2012 - 3rd International Symposium on Information and Communication Technology, pages 241–249. ACM Press. DOI: 10.1145/2350716.2350753. We develop the first bisimulation-based method of concept learning, called BBCL, for knowledge bases in description logics (DLs). Our method is formulated for a large class of useful DLs, with well-known DLs like ALC, SHIQ, SHOIQ, SROIQ. As bisimulation is the notion for characterizing indis-cernibility of objects in DLs, our method is natural and very promising. [414] Fredrik Heintz and Tommy Frnqvist. 2012. Pedagogical Experiences of Competitive Elements in an Algorithms Course. In Proceedings of LTHs 7:e Pedagogiska Inspirationskonferens (PIK). fulltext:postprint: http://liu.diva-portal.org/smash/get/div... We claim that competitive elements can improve thequality of programming and algorithms courses. To test this, weused our experience from organising national and internationalprogramming competitions to design and evaluate two differentcontests in an introductory algorithms course. The first contestturned lab assignments into a competition, where two groups rancompetitions and two were control groups and did not compete.The second, voluntary, contest, consisting of 15 internationalprogramming competition style problems, was designed tosupport student skill acquisition by providing them withopportunities for deliberate practise. We found that competitiveelements do influence student behaviour and our mainconclusions from the experiment are that students really likecompetitions, that the competition design is very important forthe resulting behaviour of the students, and that active studentsperform better on exams.We also report on an extra-curricular activity in the form of asemester long programming competition as a way of supportingstudent's deliberate practise in computer programming. [413] Bernhard Nebel and Alexander Kleiner. 2012. Multi-Agenten-Systeme in der Intralogistik - Erster Teil: Gemeinsam denken. IEE - Elektrische Automatisierung + Antriebstechnik, -(4):48–53. Hthig Verlag. Link to journal: http://www.iee-online.de/2012/ Nicht nur in der Logistik und in der Produktion setzt es sich immer mehr durch, die Steuerung und Überwachung von Aufgaben zu verteilen. Für eine solche Vorgehens- weise sind sogenannte Multi-Agenten-Systeme (MAS) geeignet, bei denen mehrere ei- genständige Systeme miteinander kommunizieren, sich koordinieren und kooperieren. Eine spezielle Form solcher MAS sind Multi-Roboter-Systeme. [412] Bernhard Nebel and Alexander Kleiner. 2012. Multi-Agenten-Systeme in der Intralogistik - Zweiter Teil: Effizient transportieren. IEE - Elektrische Automatisierung + Antriebstechnik, -(5):34–37. Hthig Verlag. Link to journal: http://www.iee-online.de/2012/ In der Logisitk, in der Produktion und und in anderen Bereichen setzt es sich immer mehr durch, zentrale Instanzen zu vermeiden und die Steuerung und Überwachung von Aufgaben zu verteilen. Für eine solche Vorgehensweise sind so genannte Multi-Agenten-Systeme (MAS) ideal geeignet, bei denen mehrere eigenständige Systeme miteinander kommunizieren, sich koordinieren und kooperieren. Eine spezielle Form solcher MAS sind Multi-Roboter-Systeme, bei denen die einzelnen Agenten sich selbständig bewegende physikalische Einheiten sind, wie z.B. bei einer Gruppe von Reinigungsrobotern, einem Roboterfußballteam oder im Logistiksystem KARIS. [411] Patrick Doherty and Fredrik Heintz. 2012. Delegation-Based Collaboration. In Proceedings of the 5th International Conference on Cognitive Systems (CogSys). [410] Barbara Dunin-Keplicz and Andrzej Szalas. 2012. Epistemic Profiles and Belief Structures. In Gordan Jezic, Mario Kusek, Ngoc-Thanh Nguyen, Robert J. Howlett, Lakhmi C. Jain, editors, Agent and Multi-Agent Systems. Technologies and Applications: 6th KES International Conference, KES-AMSTA 2012, Dubrovnik, Croatia, June 25-27, 2012. Proceedings, pages 360–369. In series: Lecture Notes in Computer Science #7327. Springer Berlin/Heidelberg. ISBN: 978-3-642-30946-5, e- 978-3-642-30947-2. DOI: 10.1007/978-3-642-30947-2_40. find book at a swedish library/hitta boken i ett svenskt bibliotek: http://libris.kb.se/bib/13481324 find book in another country/hitta boken i ett annat land: http://www.worldcat.org/search?q=Agent+a... This book constitutes the refereed proceedings of the 6th KES International Conference on Agent and Multi-Agent Systems, KES-AMSTA 2012, held in Dubrovnik, Croatia, in June 2012. <br>The conference attracted a substantial number of researchers and practitioners from all over the world who submitted their papers for ten main tracks covering the methodology and applications of agent and multi-agent systems, one workshop (TRUMAS 2012) and five special sessions on specific topics within the field. The 66 revised papers presented were carefully reviewed and selected for inclusion in the book. The papers are organized in topical sections on virtual organizations, knowledge and learning agents, intelligent workflow, cloud computing and intelligent systems, self-organization, ICT-based alternative and augmentative communication, multi-agent systems, mental and holonic models, assessment methodologies in multi-agent and other paradigms, business processing agents, Trumas 2012 (first international workshop), conversational agents and agent teams, digital economy, and multi-agent systems in distributed environments. [409] Linh Anh Nguyen and Andrzej Szalas. 2012. Paraconsistent Reasoning for Semantic Web Agents. In Ngoc Thanh Nguyen, editor, Transactions on Computational Collective Intelligence VI, pages 36–55. In series: Lecture Notes in Computer Science #7190. Springer Berlin/Heidelberg. ISBN: 978-3-642-29355-9, 978-3-642-29356-6. DOI: 10.1007/978-3-642-29356-6_2. find book at a swedish library/hitta boken i ett svenskt bibliotek: http://libris.kb.se/bib/13481193 find book in another country/hitta boken i ett annat land: http://www.worldcat.org/search?q=Transac... The LNCS journal Transactions on Computational Collective Intelligence (TCCI) focuses on all facets of computational collective intelligence (CCI) and their applications in a wide range of fields such as the Semantic Web, social networks and multi-agent systems. TCCI strives to cover new methodological, theoretical and practical aspects of CCI understood as the form of intelligence that emerges from the collaboration and competition of many individuals (artificial and/or natural). The application of multiple computational intelligence technologies such as fuzzy systems, evolutionary computation, neural systems, consensus theory, etc., aims to support human and other collective intelligence and to create new forms of CCI in natural and/or artificial systems.This, the sixth issue of Transactions on Computational Collective Intelligence contains 10 selected papers, focusing on the topics of classification, agent cooperation, paraconsistent reasoning and agent distributed mobile interaction. [408] Anders Hongslo. 2012. Stream Processing in the Robot Operating System framework. Student Thesis. 79 pages. ISRN: LIU-IDA/LITH-EX-A--12/030--SE. Streams of information rather than static databases are becoming increasingly important with the rapid changes involved in a number of fields such as finance, social media and robotics. DyKnow is a stream-based knowledge processing middleware which has been used in autonomous Unmanned Aerial Vehicle (UAV) research. ROS (Robot Operating System) is an open-source robotics framework providing hardware abstraction, device drivers, communication infrastructure, tools, libraries as well as other functionalities.This thesis describes a design and a realization of stream processing in ROS based on the stream-based knowledge processing middleware DyKnow. It describes how relevant information in ROS can be selected, labeled, merged and synchronized to provide streams of states. There are a lot of applications for such stream processing such as execution monitoring or evaluating metric temporal logic formulas through progression over state sequences containing the features of the formulas. Overviews are given of DyKnow and ROS before comparing the two and describing the design. The stream processing capabilities implemented in ROS are demonstrated through performance evaluations which show that such stream processing is fast and efficient. The resulting realization in ROS is also readily extensible to provide further stream processing functionality. [407] Viet Ha Nguyen. 2012. Design Space Exploration of the Quality of Service for Stream Reasoning Applications. Student Thesis. 35 pages. ISRN: LIU-IDA/LITH-EX-A--12/027--SE. An Unmanned Aerial Vehicle (UAV) is often an aircraft with no crew that can fly independently by a preprogrammed plan, or by remote control. Several UAV applications, like autonomously surveillance and traffic monitoring, are real-time applications. Hence tasks in these applications must complete within specied deadlines.Real Time Calculus (RTC) is a formal framework for reasoning about realtime systems and in particular streaming applications. RTC has its mathematical roots in Network Calculus. It supports timing analysis, estimating loads and predicting memory requirements.In this thesis, a formal analysis of real-time stream reasoning for UAV applications is conducted. The performance analysis is based on RTC using an abstract performance model of the streaming reasoning on board a UAV. In this study, we consider two dierent scheduling methods, first-in-first-out (FIFO) and fixed priority (FP). In the FIFO scheduling model the priorities of the tasks are assigned and processed based on the order of their arrival, while in the FP scheduling model the priorities of the tasks are preassigned. The Quality of Service (QoS) of these applications is calculated and analyzed in a proposed design space exploration framework.QoS can be defined dierently depending on what field we are studying and in this thesis we are interested in studying the delays of the real-time stream reasoning applications when (i) we fix jitters and number of instances and vary the periods, (ii) we fix the periods and number of instances and vary the jitters, and (iii) we fix the periods, jitters and vary the number of instances. [406] Fredrik Heintz and Zlatan Dragisic. 2012. Semantic Information Integration for Stream Reasoning. In Proceedings of the 15th International Conference on Information Fusion (FUSION). Linkping University Electronic Press. fulltext:postprint: http://liu.diva-portal.org/smash/get/div... The main contribution of this paper is a practicalsemantic information integration approach for stream reasoningbased on semantic matching. This is an important functionality for situation awareness applications where temporal reasoning over streams from distributed sources is needed. The integration is achieved by creating a common ontology, specifying the semantic content of streams relative to the ontology and then use semantic matching to find relevant streams. By using semantic mappings between ontologies it is also possible to do semantic matching over multiple ontologies. The complete stream reasoning approach is integrated in the Robot Operating System(ROS) and used in collaborative unmanned aircraft systems missions. [405] Anna Pernestl, Mattias Nyberg and Hkan Warnquist. 2012. Modeling and inference for troubleshooting with interventions applied to a heavy truck auxiliary braking system. Engineering applications of artificial intelligence, 25(4):705–719. Elsevier. DOI: 10.1016/j.engappai.2011.02.018. Computer assisted troubleshooting with external interventions is considered. The work is motivated by the task of repairing an automotive vehicle at lowest possible expected cost. The main contribution is a decision theoretic troubleshooting system that is developed to handle external interventions. In particular, practical issues in modeling for troubleshooting are discussed, the troubleshooting system is described, and a method for the efficient probability computations is developed. The troubleshooting systems consists of two parts; a planner that relies on AO* search and a diagnoser that utilizes Bayesian networks (BN). The work is based on a case study of an auxiliary braking system of a modern truck. Two main challenges in troubleshooting automotive vehicles are the need for disassembling the vehicle during troubleshooting to access parts to repair, and the difficulty to verify that the vehicle is fault free. These facts lead to that probabilities for faults and for future observations must be computed for a system that has been subject to external interventions that cause changes in the dependency structure. The probability computations are further complicated due to the mixture of instantaneous and non-instantaneous dependencies. To compute the probabilities, we develop a method based on an algorithm, updateBN, that updates a static BN to account for the external interventions. [404] Erik Sandewall. 2012. Maintaining Live Discussion in Two-Stage Open Peer Review. Frontiers in Computational Neuroscience, 6(9):??–??. Frontiers Research Foundation. DOI: 10.3389/fncom.2012.00009. Note: funding agencies|Knut and Alice Wallenberg Foundation|| Open peer review has been proposed for a number of reasons, in particular, for increasing the transparency of the article selection process for a journal, and for obtaining a broader basis for feedback to the authors and for the acceptance decision. The review discussion may also in itself have a value for the research community. These goals rely on the existence of a lively review discussion, but several experiments with open-process peer review in recent years have encountered the problem of faltering review discussions. The present article addresses the question of how lively review discussion may be fostered by relating the experience of the journal Electronic Transactions on Artificial Intelligence (ETAI) which was an early experiment with open peer review. Factors influencing the discussion activity are identified. It is observed that it is more difficult to obtain lively discussion when the number of contributed articles increases, which implies difficulties for scaling up the open peer review model. Suggestions are made for how this difficulty may be overcome. [403] Daniel Lazarovski. 2012. Extending the Stream Reasoning in DyKnow with Spatial Reasoning in RCC-8. Student Thesis. 74 pages. ISRN: LIU-IDA/LITH-EX-A--12/008--SE. Autonomous systems require a lot of information about the environment in which they operate in order to perform different high-level tasks. The information is made available through various sources, such as remote and on-board sensors, databases, GIS, the Internet, etc. The sensory input especially is incrementally available to the systems and can be represented as streams. High-level tasks often require some sort of reasoning over the input data, however raw streaming input is often not suitable for the higher level representations needed for reasoning. DyKnow is a stream processing framework that provides functionalities to represent knowledge needed for reasoning from streaming inputs. DyKnow has been used within a platform for task planning and execution monitoring for UAVs. The execution monitoring is performed using formula progression with monitor rules specified as temporal logic formulas. In this thesis we present an analysis for providing spatio-temporal functionalities to the formula progressor and we extend the formula progression with spatial reasoning in RCC-8. The result implementation is capable of evaluating spatio-temporal logic formulas using progression over streaming data. In addition, a ROS implementation of the formula progressor is presented as a part of a spatio-temporal stream reasoning architecture in ROS. [402] Barbara Dunin-Keplicz and Andrzej Szalas. 2012. Agents in Approximate Environments. In Jan Ejick and Rineke Verbrugge, editors, Games, Actions and Social Software: Multidisciplinary Aspects, pages 141–163. In series: Lecture Notes in Computer Science #7010. Springer. ISBN: 978-3-642-29325-2, 978-3-642-29326-9. DOI: 10.1007/978-3-642-29326-9_8. find book at a swedish library/hitta boken i ett svenskt bibliotek: http://libris.kb.se/bib/13428777 find book in another country/hitta boken i ett annat land: http://www.worldcat.org/search?q=Games%2... Edited in collaboration with FoLLI, the Association of Logic, Language and Information, this book collects a set of chapters of the multi-disciplinary project \"Games, actions and Social software\" which was carried out at the Netherlands Institute for Advanced Study in the Humanities and Social Sciences (NIAS) in Wassenaar, from September 2006 through January 2007.<br>The chapters focus on social software and the social sciences, knowledge, belief and action, perception, communication, and cooperation. [401] Patrick Doherty, Jonas Kvarnstrm and Andrzej Szalas. 2012. Temporal Composite Actions with Constraints. In Proceedings of the 13th International Conference on Principles of Knowledge Representation and Reasoning (KR), pages 478–488. AAAI Press. ISBN: 978-1-57735-560-1, 978-1-57735-561-8. Link: http://www.aaai.org/ocs/index.php/KR/KR1... Complex mission or task specification languages play a fundamentally important role in human/robotic interaction. In realistic scenarios such as emergency response, specifying temporal, resource and other constraints on a mission is an essential component due to the dynamic and contingent nature of the operational environments. It is also desirable that in addition to having a formal semantics, the language should be sufficiently expressive, pragmatic and abstract. The main goal of this paper is to propose a mission specification language that meets these requirements. It is based on extending both the syntax and semantics of a well-established formalism for reasoning about action and change, Temporal Action Logic (TAL), in order to represent temporal composite actions with constraints. Fixpoints are required to specify loops and recursion in the extended language. The results include a sound and complete proof theory for this extension. To ensure that the composite language constructs are adequately grounded in the pragmatic operation of robotic systems, Task Specification Trees (TSTs) and their mapping to these constructs are proposed. The expressive and pragmatic adequacy of this approach is demonstrated using an emergency response scenario. 2011 [400] Gianpaolo Conte and Patrick Doherty. 2011. A Visual Navigation System for UAS Based on Geo-referenced Imagery. In International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol. XXXVIII-1/C22Proceedings of the International Conference on Unmanned Aerial Vehicle in Geomatics, Zurich, Switzerland, September 14-16, 2011. In series: International Archives of Photogrammetry, Remote Sensing and Spatial Information Sciences #??. [399] Jonas Kvarnstrm. 2011. Planning for Loosely Coupled Agents Using Partial Order Forward-Chaining. In Fahiem Bacchus, Carmel Domshlak, Stefan Edelkamp, Malte Helmert, editors, Proceedings of the 21st International Conference on Automated Planning and Scheduling (ICAPS), pages 138–145. AAAI Press. ISBN: 978-1-57735-503-8, 978-1-57735-504-5. Fulltext: http://www.aaai.org/ocs/index.php/ICAPS/... We investigate a hybrid between temporal partial-order and forward-chaining planning where each action in a partially ordered plan is associated with a partially defined state. The focus is on centralized planning for multi-agent domains and on loose commitment to the precedence between actions belonging to distinct agents, leading to execution schedules that are flexible where it matters the most. Each agent, on the other hand, has a sequential thread of execution reminiscent of forward-chaining. This results in strong and informative agent-specific partial states that can be used for partial evaluation of preconditions as well as precondition control formulas used as guidance. Empirical evaluation shows the resulting planner to be competitive with TLplan and TALplanner, two other planners based on control formulas, while using a considerably more expressive and flexible plan structure. [398] Teresa Vidal-Calleja, Cyrille Berger, Joan Sol and Simon Lacroix. 2011. Large scale multiple robot visual mapping with heterogeneous landmarks in semi-structured terrain. Robotics and Autonomous Systems, 59(9):654–674. Elsevier. DOI: 10.1016/j.robot.2011.05.008. This paper addresses the cooperative localization and visual mapping problem with multiple heterogeneous robots. The approach is designed to deal with the challenging large semi-structured outdoors environments in which aerial/ground ensembles are to evolve. We propose the use of heterogeneous visual landmarks, points and line segments, to achieve effective cooperation in such environments. A large-scale SLAM algorithm is generalized to handle multiple robots, in which a global graph maintains the relative relationships between a series of local sub-maps built by the different robots. The key issue when dealing with multiple robots is to find the link between them, and to integrate these relations to maintain the overall geometric consistency; the events that introduce these links on the global graph are described in detail. Monocular cameras are considered as the primary extereoceptive sensor. In order to achieve the undelayed initialization required by the bearing-only observations, the well-known inverse-depth parametrization is adopted to estimate 3D points. Similarly, to estimate 3D line segments, we present a novel parametrization based on anchored Plücker coordinates, to which extensible endpoints are added. Extensive simulations show the proposed developments, and the overall approach is illustrated using real-data taken with a helicopter and a ground rover. [397] Patrick Doherty, Fredrik Heintz and David Landn. 2011. A Delegation-Based Collaborative Robotic Framework. In Christian Guttmann, editor, Proceedings of the 3rd International Workshop on Collaborative Agents - Research and development. fulltext:postprint: http://liu.diva-portal.org/smash/get/div... [396] Anders Kofod-Peteresen, Fredrik Heintz and Langseth Helge. 2011. Elevent Scandinavian Conference on Artifical Intelligence SCAI 2011. Conference Proceedings. In series: Frontiers in Artificial Intelligence and Applications #227. IOS Press. 197 pages. ISBN: 978-1-60750-753-6. [395] Patrick Doherty, Fredrik Heintz and David Landn. 2011. A Delegation-Based Architecture for Collaborative Robotics. In Danny Weyns and Marie-Pierre Gleizes, editors, Agent-Oriented Software Engineering XI: 11th International Workshop, AOSE 2010, Toronto, Canada, May 10-11, 2010, Revised Selected Papers, pages 205–247. In series: Lecture Notes in Computer Science #6788. Springer Berlin/Heidelberg. ISBN: 978-3-642-22635-9. DOI: 10.1007/978-3-642-22636-6_13. Find book in another country/Hitta boken i ett annat land: http://www.worldcat.org/search?q=978-3-6... find book at a swedish library/hitta boken i ett svenskt bibliotek: http://libris.kb.se/bib/12509689 Collaborative robotic systems have much to gain by leveraging results from the area of multi-agent systems and in particular agent-oriented software engineering. Agent-oriented software engineering has much to gain by using collaborative robotic systems as a testbed. In this article, we propose and specify a formally grounded generic collaborative system shell for robotic systems and human operated ground control systems. Collaboration is formalized in terms of the concept of delegation and delegation is instantiated as a speech act. Task Specification Trees are introduced as both a formal and pragmatic characterization of tasks and tasks are recursively delegated through a delegation process implemented in the collaborative system shell. The delegation speech act is formally grounded in the implementation using Task Specification Trees, task allocation via auctions and distributed constraint problem solving. The system is implemented as a prototype on Unmanned Aerial Vehicle systems and a case study targeting emergency service applications is presented. [394] Patrick Doherty and Fredrik Heintz. 2011. A Delegation-Based Cooperative Robotic Framework. In Proceedings of the IEEE International Conference on Robotics and Biomimetic, pages 2955–2962. IEEE conference proceedings. ISBN: 978-1-4577-2136-6. DOI: 10.1109/ROBIO.2011.6181755. fulltext:postprint: http://liu.diva-portal.org/smash/get/div... Cooperative robotic systems, such as unmanned aircraft systems, are becoming technologically mature enough to be integrated into civil society. To gain practical use and acceptance, a verifiable, principled and well-defined foundation for interactions between human operators and autonomous systems is needed. In this paper, we propose and specify such a formally grounded collaboration framework. Collaboration is formalized in terms of the concept of delegation and delegation is instantiated as a speech act. Task Specification Trees are introduced as both a formal and pragmatic characterization of tasks and tasks are recursively delegated through a delegation process. The delegation speech act is formally grounded in the implementation using Task Specification Trees, task allocation via auctions and distributed constraint solving. The system is implemented as a prototype on unmanned aerial vehicle systems and a case study targeting emergency service applications is presented. [393] Jan Maluszynski and Andrzej Szalas. 2011. Living with Inconsistency and Taming Nonmonotonicity. In O. de Moor, G. Gottlob, T. Furche, A. Sellers, editors, Datalog Reloaded, pages 334–398. In series: Lecture Notes in Computer Science #6702. Springer Berlin/Heidelberg. ISBN: 978-3-642-24205-2. DOI: 10.1007/978-3-642-24206-9_22. In this paper we consider rule-based query languages with negation inbodies and heads of rules, traditionally denoted by DATALOG--. Tractable andat the same time intuitive semantics for DATALOG-- has not been provided evenif the area of deductive databases is over 30 years old. In this paper we identifysources of the problem and propose a query language, which we call 4QL.The 4QL language supports a modular and layered architecture and providesa tractable framework for many forms of rule-based reasoning both monotonicand nonmonotonic. As the underpinning principle we assume openness of theworld, which may lead to the lack of knowledge. Negation in rule heads may leadto inconsistencies. To reduce the unknown/inconsistent zones we introduce simpleconstructs which provide means for application-specific disambiguation ofinconsistent information, the use of Local Closed World Assumption (thus alsoClosed World Assumption, if needed), as well as various forms of default anddefeasible reasoning. [392] Son Thanh Cao, Linh Anh Nguyen and Andrzej Szalas. 2011. WORL: A Web Ontology Rule Language. In Proceedings of the 3rd International Conference on Knowledge and Systems Engineering (KSE), pages 32–39. IEEE. ISBN: 978-1-4577-1848-9. DOI: 10.1109/KSE.2011.14. We develop a Web ontology rule language, called WORL, which combines a variant of OWL 2 RL with eDatalog-with-negation. We disallow the features of OWL 2 RL that play the role of constraints (i.e., the ones that are translated to negative clauses), but allow additional features like negation, the minimal number restriction and unary external checkable predicates to occur in the left hand side of concept inclusion axioms. Some restrictions are adopted to guarantee a translation into eDatalog-with-negation. We also develop the well-founded semantics for WORL and the standard semantics for stratified WORL (SWORL) via translation into eDatalog-with-negation. Both WORL and SWORL have PTime data complexity. In contrast to the existing combined formalisms, in WORL and SWORL negation in concept inclusion axioms is interpreted using nonmonotonic semantics. [391] Patrick Doherty, Barbara Dunin-Keplicz and Andrzej Szalas. 2011. Tractable model checking for fragments of higher-order coalition logic. In Liz Sonenberg, Peter Stone, Kagan Tumer, Pinar Yolum, editors, Proceedings of the 10th International Conference on Autonomous Agents and Multiagent Systems - Volume 2, pages 743–750. AAAI Press. ISBN: 0-9826571-6-1, 978-0-9826571-6-4. Link: http://dl.acm.org/citation.cfm?id=203172... A number of popular logical formalisms for representing and reasoning about the abilities of teams or coalitions of agents have been proposed beginning with the Coalition Logic (CL) of Pauly. Ågotnes et al introduced a means of succinctly expressing quantification over coalitions without compromising the computational complexity of model checking in CL by introducing Quantified Coalition Logic (QCL). QCL introduces a separate logical language for characterizing coalitions in the modal operators used in QCL. Boella et al, increased the representational expressibility of such formalisms by introducing Higher-Order Coalition Logic (HCL), a monadic second-order logic with special set grouping operators. Tractable fragments of HCL suitable for efficient model checking have yet to be identified. In this paper, we relax the monadic restriction used in HCL and restrict ourselves to the diamond operator. We show how formulas using the diamond operator are logically equivalent to second-order formulas. This permits us to isolate and define well-behaved expressive fragments of second-order logic amenable to model-checking in PTime. To do this, we appeal to techniques used in deductive databases and quantifier elimination. In addition, we take advantage of the monotonicity of the effectivity function resulting in exponentially more succinct representation of models. The net result is identification of highly expressible fragments of a generalized HCL where model checking can be done efficiently in PTime. [390] Son Thanh Cao, Anh Linh Nguyen and Andrzej Szalas. 2011. On the Web Ontology Rule Language OWL 2 RL. In Piotr Jedrzejowicz, Ngoc Thanh Nguyen and Kiem Hoang, editors, Proceedings of the 3rd International Conference on Computational Collective Intelligence, Technologies and Applications (ICCCI), pages 254–264. In series: Lecture Notes in Computer Science #6922. Springer Berlin/Heidelberg. ISBN: 978-3-642-23934-2. DOI: 10.1007/978-3-642-23935-9_25. It is known that the OWL 2 RL Web Ontology Language Profile has PTime data complexity and can be translated into Datalog. However, a knowledge base in OWL 2 RL may be unsatisfiable. The reason is that, when translated into Datalog, the result may consist of a Datalog program and a set of constraints in the form of negative clauses. In this paper we first identify a maximal fragment of OWL 2 RL called OWL 2 RL + with the property that every knowledge base expressed in this fragment can be translated into a Datalog program and hence is satisfiable. We then propose some extensions of OWL 2 RL and OWL 2 RL + that still have PTime data complexity. [389] Patrick Doherty, Tomasz Michalak, Jacek Sroka and Andrzej Szalas. 2011. Contextual Coalitional Games. In Mohua Banerjee, Anil Seth, editors, Proceedings of the 4th Indian Conference on Logic and its Applications (ICLA), pages 65–78. In series: Lecture Notes in Artificial Intelligence #6521. Springer Berlin/Heidelberg. DOI: 10.1007/978-3-642-18026-2_7. The study of cooperation among agents is of central interest in multi-agent systems research. A popular way to model cooperation is through coalitional game theory. Much research in this area has had limited practical applicability as regards real-world multi-agent systems due to the fact that it assumesdeterministic payoffs to coalitions and in addition does not apply to multi-agent environments that arestochastic in nature. In this paper, we propose a novel approach to modeling such scenarios where coalitional games will be contextualized through the use of logical expressions representing environmental and other state, and probability distributions will be placed on the space of contexts in order to model the stochastic nature of the scenarios. More formally, we present a formal representation language for representing contextualized coalitional games embedded in stochastic environments and we define and show how to compute expected Shapley values in such games in a computationally efficient manner. We present the value of the approach through an example involving robotics assistance in emergencies. [388] Barbara Dunin-Keplicz, Anh Linh Nguyen and Andrzej Szalas. 2011. Converse-PDL with Regular Inclusion Axioms: A Framework for MAS Logics. Journal of Applied Non-Classical Logics, 21(1):61–91. Lavoisier. DOI: 10.3166/JANCL.21.61-91. In this paper we study automated reasoning in the modal logic CPDLreg which is a combination of CPDL (Propositional Dynamic Logic with Converse) and REGc (Regular Grammar Logic with Converse). The logic CPDL is widely used in many areas, including program verification, theory of action and change, and knowledge representation. On the other hand, the logic REGc is applicable in reasoning about epistemic states and ontologies (via Description Logics). The modal logic CPDLreg can serve as a technical foundation for reasoning about agency. Even very rich multi-agent logics can be embedded into CPDLreg via a suitable translation. Therefore, CPDLreg can serve as a test bed to implement and possibly verify new ideas without providing specific automated reasoning techniques for the logic in question. This process can to a large extent be automated. The idea of embedding various logics into CPDLreg is illustrated on a rather advanced logic TEAMLOGK designed to specify teamwork in multi-agent systems. Apart from defining informational and motivational attitudes of groups of agents, TEAMLOGK allows for grading agents' beliefs, goals and intentions. The current paper is a companion to our paper (Dunin-Kęplicz et al., 2010a). The main contribution are proofs of soundness and completeness of the tableau calculus for CPDLreg provided in (Dunin-Kęplicz et al., 2010a). [387] Linh Anh Nguyen and Andrzej Szalas. 2011. ExpTime Tableau Decision Procedures for Regular Grammar Logics with Converse. Studia Logica: An International Journal for Symbolic Logic, 98(3):387–428. Springer Berlin/Heidelberg. DOI: 10.1007/s11225-011-9341-3. Grammar logics were introduced by Fariñas del Cerro and Penttonen in 1988 and have been widely studied. In this paper we consider regular grammar logics with converse (REG c logics) and present sound and complete tableau calculi for the general satisfiability problem of REG c logics and the problem of checking consistency of an ABox w.r.t. a TBox in a REG c logic. Using our calculi we develop ExpTime (optimal) tableau decision procedures for the mentioned problems, to which various optimization techniques can be applied. We also prove a new result that the data complexity of the instance checking problem in REG clogics is coNP-complete. [386] Jan Maluszynski and Andrzej Szalas. 2011. Logical Foundations and Complexity of 4QL, a Query Language with Unrestricted Negation. Journal of Applied Non-Classical Logics, 21(2):211–232. Lavoisier. DOI: 10.3166/JANCL.21.211-232. The paper discusses properties of 4QL, a DATALOG¬¬-like query language, originally outlined by Małuszy´nski and Szałas (Małuszy´nski & Szałas, 2011). 4QL allows one to use rules with negation in heads and bodies of rules. It is based on a simple and intuitive semantics and provides uniform tools for “lightweight” versions of known forms of nonmonotonic reasoning. Negated literals in heads of rules may naturally lead to inconsistencies. On the other hand, rules do not have to attach meaning to some literals. Therefore 4QL is founded on a four-valued semantics, employing the logic introduced in (Małuszy´nski et al., 2008; Vitória et al., 2009) with truth values: ‘true’, ‘false’, ‘inconsistent’ and ‘unknown’. In addition, 4QL is tractable w.r.t. data complexity and captures PTIME queries. Even though DATALOG¬¬ is known as a concept for the last 30 years, to our best knowledge no existing approach enjoys these properties. In the current paper we:
• investigate properties of well-supported models of 4QL
• prove the correctness of the algorithm for computing well-supported models
• show that 4QL has PTIME data complexity and captures PTIME.
[385] Zlatan Dragisic. 2011. Semantic Matching for Stream Reasoning. Student Thesis. 110 pages. ISRN: LIU-IDA/LITH-EX-A--11/041--SE. Autonomous system needs to do a great deal of reasoning during execution in order to provide timely reactions to changes in their environment. Data needed for this reasoning process is often provided through a number of sensors. One approach for this kind of reasoning is evaluation of temporal logical formulas through progression. To evaluate these formulas it is necessary to provide relevant data for each symbol in a formula. Mapping relevant data to symbols in a formula could be done manually, however as systems become more complex it is harder for a designer to explicitly state and maintain thismapping. Therefore, automatic support for mapping data from sensors to symbols would make system more flexible and easier to maintain.DyKnow is a knowledge processing middleware which provides the support for processing data on different levels of abstractions. The output from the processing components in DyKnow is in the form of streams of information. In the case of DyKnow, reasoning over incrementally available data is done by progressing metric temporal logical formulas. A logical formula contains a number of symbols whose values over time must be collected and synchronized in order to determine the truth value of the formula. Mapping symbols in formula to relevant streams is done manually in DyKnow. The purpose of this matching is for each variable to find one or more streams whose content matches the intended meaning of the variable.This thesis analyses and provides a solution to the process of semantic matching. The analysis is mostly focused on how the existing semantic technologies such as ontologies can be used in this process. The thesis also analyses how this process can be used for matching symbols in a formula to content of streams on distributed and heterogeneous platforms. Finally, the thesis presents an implementation in the Robot Operating System (ROS). The implementation is tested in two case studies which cover a scenario where there is only a single platform in a system and a scenario where there are multiple distributed heterogeneous platforms in a system.The conclusions are that the semantic matching represents an important step towards fully automatized semantic-based stream reasoning. Our solution also shows that semantic technologies are suitable for establishing machine-readable domain models. The use of these technologies made the semantic matching domain and platform independent as all domain and platform specific knowledge is specified in ontologies. Moreover, semantic technologies provide support for integration of data from heterogeneous sources which makes it possible for platforms to use streams from distributed sources. [384] Mark Buller, Paul Cuddihy, Ernest Davis, Patrick Doherty, Finale Doshi-Velez, Esra Erdem, Douglas Fisher, Nancy Green, Knut Hinkelmann, James McLurkin, Mary Lou Maher, Rajiv Maheswaran, Sara Rubinelli, Nathan Schurr, Donia Scott, Dylan Shell, Pedro Szekely, Barbara Thoenssen and Arnold B Urken. 2011. Reports of the AAAI 2011 Spring Symposia. The AI Magazine, 32(3):119–127. AAAI Press. The Association for the Advancement of Artificial Intelligence presented the 2011 Spring Symposium Series Monday through Wednesday, March 21-23, 2011, at Stanford University. This report summarizes the eight symposia. [383] Piotr Rudol. 2011. Increasing Autonomy of Unmanned Aircraft Systems Through the Use of Imaging Sensors. Licentiate Thesis. In series: Linkping Studies in Science and Technology. Thesis #1510. Linkping University Electronic Press. 96 pages. ISBN: 978-91-7393-034-5. The range of missions performed by Unmanned Aircraft Systems (UAS) has been steadily growing in the past decades thanks to continued development in several disciplines. The goal of increasing the autonomy of UAS's is widening the range of tasks which can be carried out without, or with minimal, external help. This thesis presents methods for increasing specific aspects of autonomy of UAS's operating both in outdoor and indoor environments where cameras are used as the primary sensors.First, a method for fusing color and thermal images for object detection, geolocation and tracking for UAS's operating primarily outdoors is presented. Specifically, a method for building saliency maps where human body locations are marked as points of interest is described. Such maps can be used in emergency situations to increase the situational awareness of first responders or a robotic system itself. Additionally, the same method is applied to the problem of vehicle tracking. A generated stream of geographical locations of tracked vehicles increases situational awareness by allowing for qualitative reasoning about, for example, vehicles overtaking, entering or leaving crossings.Second, two approaches to the UAS indoor localization problem in the absence of GPS-based positioning are presented. Both use cameras as the main sensors and enable autonomous indoor ight and navigation. The first approach takes advantage of cooperation with a ground robot to provide a UAS with its localization information. The second approach uses marker-based visual pose estimation where all computations are done onboard a small-scale aircraft which additionally increases its autonomy by not relying on external computational power. [382] Mariusz Wzorek. 2011. Selected Aspects of Navigation and Path Planning in Unmanned Aircraft Systems. Licentiate Thesis. In series: Linkping Studies in Science and Technology. Thesis #1509. Linkping University Electronic Press. 107 pages. ISBN: 978-91-7393-037-6. Unmanned aircraft systems (UASs) are an important future technology with early generations already being used in many areas of application encompassing both military and civilian domains. This thesis proposes a number of integration techniques for combining control-based navigation with more abstract path planning functionality for UASs. These techniques are empirically tested and validated using an RMAX helicopter platform used in the UASTechLab at Linköping University. Although the thesis focuses on helicopter platforms, the techniques are generic in nature and can be used in other robotic systems.At the control level a navigation task is executed by a set of control modes. A framework based on the abstraction of hierarchical concurrent state machines for the design and development of hybrid control systems is presented. The framework is used to specify reactive behaviors and for sequentialisation of control modes. Selected examples of control systems deployed on UASs are presented. Collision-free paths executed at the control level are generated by path planning algorithms.We propose a path replanning framework extending the existing path planners to allow dynamic repair of flight paths when new obstacles or no-fly zones obstructing the current flight path are detected. Additionally, a novel approach to selecting the best path repair strategy based on machine learning technique is presented. A prerequisite for a safe navigation in a real-world environment is an accurate geometrical model. As a step towards building accurate 3D models onboard UASs initial work on the integration of a laser range finder with a helicopter platform is also presented.Combination of the techniques presented provides another step towards building comprehensive and robust navigation systems for future UASs. [381] David Landn. 2011. Complex Task Allocation for Delegation: From Theory to Practice. Licentiate Thesis. In series: Linkping Studies in Science and Technology. Thesis #1506. Linkping University Electronic Press. 139 pages. ISBN: 978-91-7393-048-2. The problem of determining who should do what given a set of tasks and a set of agents is called the task allocation problem. The problem occurs in many multi-agent system applications where a workload of tasks should be shared by a number of agents. In our case, the task allocation problem occurs as an integral part of a larger problem of determining if a task can be delegated from one agent to another.Delegation is the act of handing over the responsibility for something to someone. Previously, a theory for delegation including a delegation speech act has been specified. The speech act specifies the preconditions that must be fulfilled before the delegation can be carried out, and the postconditions that will be true afterward. To actually use the speech act in a multi-agent system, there must be a practical way of determining if the preconditions are true. This can be done by a process that includes solving a complex task allocation problem by the agents involved in the delegation.In this thesis a constraint-based task specification formalism, a complex task allocation algorithm for allocating tasks to unmanned aerial vehicles and a generic collaborative system shell for robotic systems are developed. The three components are used as the basis for a collaborative unmanned aircraft system that uses delegation for distributing and coordinating the agents' execution of complex tasks. [380] Marjan Alirezaie. 2011. Semantic Analysis Of Multi Meaning Words Using Machine Learning And Knowledge Representation. Student Thesis. 74 pages. ISRN: LiU/IDA-EX-A- -11/011- -SE. The present thesis addresses machine learning in a domain of naturallanguage phrases that are names of universities. It describes two approaches to this problem and a software implementation that has made it possible to evaluate them and to compare them.In general terms, the system's task is to learn to 'understand' the significance of the various components of a university name, such as the city or region where the university is located, the scienti c disciplines that are studied there, or the name of a famous person which may be part of the university name. A concrete test for whether the system has acquired this understanding is when it is able to compose a plausible university name given some components that should occur in the name.In order to achieve this capability, our system learns the structure of available names of some universities in a given data set, i.e. it acquires a grammar for the microlanguage of university names. One of the challenges is that the system may encounter ambiguities due to multi meaning words. This problem is addressed using a small ontology that is created during the training phase.Both domain knowledge and grammatical knowledge is represented using decision trees, which is an ecient method for concept learning. Besides for inductive inference, their role is to partition the data set into a hierarchical structure which is used for resolving ambiguities.The present report also de nes some modi cations in the de nitions of parameters, for example a parameter for entropy, which enable the system to deal with cognitive uncertainties. Our method for automatic syntax acquisition, ADIOS, is an unsupervised learning method. This method is described and discussed here, including a report on the outcome of the tests using our data set.The software that has been implemented and used in this project has been implemented in C. [379] Hkan Warnquist. 2011. Computer-Assisted Troubleshooting for Efficient Off-board Diagnosis. Licentiate Thesis. In series: Linkping Studies in Science and Technology. Thesis #1490. Linkping University Electronic Press. 169 pages. ISBN: 978-91-7393-151-9. This licentiate thesis considers computer-assisted troubleshooting of complex products such as heavy trucks. The troubleshooting task is to find and repair all faulty components in a malfunctioning system. This is done by performing actions to gather more information regarding which faults there can be or to repair components that are suspected to be faulty. The expected cost of the performed actions should be as low as possible.The work described in this thesis contributes to solving the troubleshooting task in such a way that a good trade-off between computation time and solution quality can be made. A framework for troubleshooting is developed where the system is diagnosed using non-stationary dynamic Bayesian networks and the decisions of which actions to perform are made using a new planning algorithm for Stochastic Shortest Path Problems called Iterative Bounding LAO*.It is shown how the troubleshooting problem can be converted into a Stochastic Shortest Path problem so that it can be efficiently solved using general algorithms such as Iterative Bounding LAO*. New and improved search heuristics for solving the troubleshooting problem by searching are also presented in this thesis.The methods presented in this thesis are evaluated in a case study of an auxiliary hydraulic braking system of a modern truck. The evaluation shows that the new algorithm Iterative Bounding LAO* creates troubleshooting plans with a lower expected cost faster than existing state-of-the-art algorithms in the literature. The case study shows that the troubleshooting framework can be applied to systems from the heavy vehicles domain. [378] Per-Magnus Olsson. 2011. Positioning Algorithms for Surveillance Using Unmanned Aerial Vehicles. Licentiate Thesis. In series: Linkping Studies in Science and Technology. Thesis #1476. Linkping University Electronic Press. 140 pages. ISBN: 978-91-7393-200-4. Surveillance is an important application for unmanned aerial vehicles (UAVs). The sensed information often has high priority and it must be made available to human operators as quickly as possible. Due to obstacles and limited communication range, it is not always possible to transmit the information directly to the base station. In this case, other UAVs can form a relay chain between the surveillance UAV and the base station. Determining suitable positions for such UAVs is a complex optimization problem in and of itself, and is made even more difficult by communication and surveillance constraints.To solve different variations of finding positions for UAVs for surveillance of one target, two new algorithms have been developed. One of the algorithms is developed especially for finding a set of relay chains offering different trade-offs between the number of UAVsand the quality of the chain. The other algorithm is tailored towards finding the highest quality chain possible, given a limited number of available UAVs.Finding the optimal positions for surveillance of several targets is more difficult. A study has been performed, in order to determine how the problems of interest can besolved. It turns out that very few of the existing algorithms can be used due to the characteristics of our specific problem. For this reason, an algorithm for quickly calculating positions for surveillance of multiple targets has been developed. This enables calculation of an initial chain that is immediately made available to the user, and the chain is then incrementally optimized according to the user’s desire. [377] Erik Sandewall. 2011. From systems to logic in the early development of nonmonotonic reasoning. Artificial Intelligence, 175(1):416–427. Elsevier. DOI: 10.1016/j.artint.2010.04.013. This note describes how the notion of nonmonotonic reasoning emerged in Artificial Intelligence from the mid-1960s to 1980. It gives particular attention to the interplay between three kinds of activities: design of high-level programming systems for AI, design of truth-maintenance systems, and the development of nonmonotonic logics. This was not merely a development from logic to implementation: in several cases there was a development from a system design to a corresponding logic. The article concludes with some reflections on the roles and relationships between logicist theory and system design in AI, and in particular in Knowledge Representation. 2010 [376] Erik Sandewall. 2010. Exercising Moral Copyright for Evolving Publications. ScieCom Info, 6(3):??–??. Svenskt Resurscentrum fr Vetenskaplig Kommunikation. Link: http://www.sciecom.org/ojs/index.php/sci... [375] Barbara Dunin-Keplicz, Anh Linh Nguyen and Andrzej Szalas. 2010. Graded Beliefs, Goals and Intentions. In Proceedings of the 3rd Workshop on Logical Aspects of Multi-Agent Systems (LAMAS), pages 1–15. AAAI Press. [374] Cyrille Berger and Simon Lacroix. 2010. DSeg: Dtection directe de segments dans une image. In 17me congrs francophone AFRIF-AFIA Reconnaissance des Formes et Intelligence Artificielle (RFIA). Cet article présente une approche model-driven'' pour détecter des segmentsde droite dans une image. L'approche détecte les segments de manièreincrémentale sur la base du gradient de l'image, en exploitant un filtre deKalman linéaire qui estime les paramètres de la droite support des segments etles variances associées. Les algorithmes sont rapides et robustes au bruit etaux variations d'illumination de la scène perçue, ils permettent de détecterdes segments plus longs que les approches existantes guidées par les données(data-driven''), et ils ne nécessitent pas de délicate détermination deparamètres. Des résultats avec différentes conditions d'éclairage et descomparaisons avec les approches existantes sont présentés. [373] Anh Linh Nguyen and Andrzej Szalas. 2010. Three-Valued Paraconsistent Reasoning for Semantic Web Agents. In Proceedings of the 4th International KES Symposium on Agents and Multi-agent Systems ? Technologies and Applications (KES-AMSTA), pages 152–162. In series: Lecture Notes in Artificial Intelligence #6070. Springer. ISBN: 978-3-642-13479-1. DOI: 10.1007/978-3-642-13480-7_17. Description logics [1] refer to a family of formalisms concentrated around concepts, roles and individuals. They are used in many multiagent and semantic web applications as a foundation for specifying knowledge bases and reasoning about them. One of widely applied description logics is SHIQ [7,8]. In the current paper we address the problem of inconsistent knowledge. Inconsistencies may naturally appear in the considered application domains, for example as a result of fusing knowledge from distributed sources. We define three three-valued paraconsistent semantics for SHIQ, reflecting different meanings of concept inclusion of practical importance. We also provide a quite general syntactic condition of safeness guaranteeing satisfiability of a knowledge base w.r.t. three-valued semantics and define a faithful translation of our formalism into a suitable version of a two-valued description logic. Such a translation allows one to use existing tools and SHIQ reasoners to deal with inconsistent knowledge. [372] Anh Linh Nguyen and Andrzej Szalas. 2010. Tableaux with Global Caching for Checking Satisfiability of a Knowledge Base in the Description Logic SH. Transactions on Computational Collective Intelligence, 1(1):21–38. Springer. ISBN: 978-3-642-15033-3. DOI: 10.1007/978-3-642-15034-0_2. Description logics (DLs) are a family of knowledge representation languages which can be used to represent the terminological knowledge of an application domain in a structured and formally well-understood way. DLs can be used, for example, for conceptual modeling or as ontology languages. In fact, OWL (Web Ontology Language), recommended by W3C, is based on description logics. In the current paper we give the first direct ExpTime (optimal) tableau decision procedure, which is not based on transformation or on the pre-completion technique, for checking satisfiability of a knowledge base in the description logic SH. Our procedure uses sound global caching and can be implemented as an extension of the highly optimized tableau prover TGC to obtain an efficient program for the mentioned satisfiability problem. [371] Erik Sandewall. 2010. Defeasible inheritance with doubt index and its axiomatic characterization. Artificial Intelligence, 174(18):1431–1459. Elsevier. DOI: 10.1016/j.artint.2010.09.001. This article introduces and uses a representation of defeasible inheritance networks where links in the network are viewed as propositions, and where defeasible links are tagged with a quantitative indication of the proportion of exceptions, called the doubt index. This doubt index is used for restricting the length of the chains of inference. The representation also introduces the use of defeater literals that disable the chaining of subsumption links. The use of defeater literals replaces the use of negative defeasible inheritance links, expressing \"most A are not B\". The new representation improves the expressivity significantly. Inference in inheritance networks is defined by a combination of axioms that constrain the contents of network extensions, a heuristic restriction that also has that effect, and a nonmonotonic operation of minimizing the set of defeater literals while retaining consistency. We introduce an underlying semantics that defines the meaning of literals in a network, and prove that the axioms are sound with respect to this semantics. We also discuss the conditions for obtaining completeness. Traditional concepts, assumptions and issues in research on nonmonotonic or defeasible inheritance are reviewed in the perspective of this approach. [370] Linh Anh Nguyen and Andrzej Szalas. 2010. Checking Consistency of an ABox w.r.t. Global Assumptions in PDL. Fundamenta Informaticae, 102(1):97–113. IOS Press. DOI: 10.3233/FI-2010-299. We reformulate Pratts tableau decision procedure of checking satisfiability of a set of formulas in PDL. Our formulation is simpler and its implementation is more direct. Extending the method we give the first Ex PT m E (optimal) tableau decision procedure not based on transformation for checking consistency of an ABox w.r.t. a TBox in PDL (here, PDL is treated as a description logic). We also prove a new result that the data complexity of the instance checking problem in PDL is coNP-complete. [369] Patrick Doherty, Jonas Kvarnstrm, Fredrik Heintz, David Landn and Per-Magnus Olsson. 2010. Research with Collaborative Unmanned Aircraft Systems. In Gerhard Lakemeyer, Hector J. Levesque, Fiora Pirri, editors, Proceedings of the Dagstuhl Workshop on Cognitive Robotics. In series: Dagstuhl Seminar Proceedings #10081. Leibniz-Zentrum fr Informatik. We provide an overview of ongoing research which targets development of a principled framework for mixed-initiative interaction with unmanned aircraft systems (UAS). UASs are now becoming technologically mature enough to be integrated into civil society. Principled interaction between UASs and human resources is an essential component in their future uses in complex emergency services or bluelight scenarios. In our current research, we have targeted a triad of fundamental, interdependent conceptual issues: delegation, mixed- initiative interaction and adjustable autonomy, that is being used as a basis for developing a principled and well-defined framework for interaction. This can be used to clarify, validate and verify different types of interaction between human operators and UAS systems both theoretically and practically in UAS experimentation with our deployed platforms. [368] Oleg Burdakov, Patrick Doherty, Kaj Holmberg and Per-Magnus Olsson. 2010. Optimal placement of UV-based communications relay nodes. Journal of Global Optimization, 48(4):511–531. Springer. DOI: 10.1007/s10898-010-9526-8. Note: The original publication is available at www.springerlink.com:Oleg Burdakov, Patrick Doherty, Kaj Holmberg and Per-Magnus Olsson, Optimal placement of UV-based communications relay nodes, 2010, Journal of Global Optimization, (48), 4, 511-531.http://dx.doi.org/10.1007/s10898-010-9526-8Copyright: Springer Science Business Mediahttp://www.springerlink.com/ We consider a constrained optimization problem with mixed integer and real variables. It models optimal placement of communications relay nodes in the presence of obstacles. This problem is widely encountered, for instance, in robotics, where it is required to survey some target located in one point and convey the gathered information back to a base station located in another point. One or more unmanned aerial or ground vehicles (UAVs or UGVs) can be used for this purpose as communications relays. The decision variables are the number of unmanned vehicles (UVs) and the UV positions. The objective function is assumed to access the placement quality. We suggest one instance of such a function which is more suitable for accessing UAV placement. The constraints are determined by, firstly, a free line of sight requirement for every consecutive pair in the chain and, secondly, a limited communication range. Because of these requirements, our constrained optimization problem is a difficult multi-extremal problem for any fixed number of UVs. Moreover, the feasible set of real variables is typically disjoint. We present an approach that allows us to efficiently find a practically acceptable approximation to a global minimum in the problem of optimal placement of communications relay nodes. It is based on a spatial discretization with a subsequent reduction to a shortest path problem. The case of a restricted number of available UVs is also considered here. We introduce two label correcting algorithms which are able to take advantage of using some peculiarities of the resulting restricted shortest path problem. The algorithms produce a Pareto solution to the two-objective problem of minimizing the path cost and the number of hops. We justify their correctness. The presented results of numerical 3D experiments show that our algorithms are superior to the conventional Bellman-Ford algorithm tailored to solving this problem. [367] Piotr Rudol, Mariusz Wzorek and Patrick Doherty. 2010. Vision-based Pose Estimation for Autonomous Indoor Navigation of Micro-scale Unmanned Aircraft Systems. In Proceedings of the 2010 IEEEInternational Conference on Robotics and Automation (ICRA), pages 1913–1920. In series: Proceedings - IEEE International Conference on Robotics and Automation #2010. IEEE conference proceedings. ISBN: 978-1-4244-5038-1. DOI: 10.1109/ROBOT.2010.5509203. We present a navigation system for autonomous indoor flight of micro-scale Unmanned Aircraft Systems (UAS) which is based on a method for accurate monocular vision pose estimation. The method makes use of low cost artificial landmarks placed in the environment and allows for fully autonomous flight with all computation done on-board a UAS on COTS hardware. We provide a detailed description of all system components along with an accuracy evaluation and a time profiling result for the pose estimation method. Additionally, we show how the system is integrated with an existing micro-scale UAS and provide results of experimental autonomous flight tests. To our knowledge, this system is one of the first to allow for complete closed-loop control and goal-driven navigation of a micro-scale UAS in an indoor setting without requiring connection to any external entities. [366] Mariusz Wzorek, Jonas Kvarnstrm and Patrick Doherty. 2010. Choosing Path Replanning Strategies for Unmanned Aircraft Systems. In Ronen Brafman, Héctor Geffner, Jörg Hoffmann, Henry Kautz, editors, Proceedings of the Twentieth International Conference on Automated Planning and Scheduling (ICAPS), pages 193–200. AAAI Press. ISBN: 978-1-57735-449-9. Unmanned aircraft systems use a variety of techniques to plan collision-free flight paths given a map of obstacles and no- fly zones. However, maps are not perfect and obstacles may change over time or be detected during flight, which may in- validate paths that the aircraft is already following. Thus, dynamic in-flight replanning is required.Numerous strategies can be used for replanning, where the time requirements and the plan quality associated with each strategy depend on the environment around the original flight path. In this paper, we investigate the use of machine learn- ing techniques, in particular support vector machines, to choose the best possible replanning strategy depending on the amount of time available. The system has been implemented, integrated and tested in hardware-in-the-loop simulation with a Yamaha RMAX helicopter platform. [365] Fredrik Heintz, Jonas Kvarnstrm and Patrick Doherty. 2010. Stream-Based Reasoning in DyKnow. In Gerhard Lakemeyer and Hector J. Levesque and Fiora Pirri, editors, Proceedings of the Dagstuhl Workshop on Cognitive Robotics. In series: Dagstuhl Seminar Proceedings #10081. Leibniz-Zentrum fr Informatik. The information available to modern autonomous systems is often in the form of streams. As the number of sensors and other stream sources increases there is a growing need for incremental reasoning about the incomplete content of sets of streams in order to draw relevant conclusions and react to new situations as quickly as possible. To act rationally, autonomous agents often depend on high level reasoning components that require crisp, symbolic knowledge about the environment. Extensive processing at many levels of abstraction is required to generate such knowledge from noisy, incomplete and quantitative sensor data. We define knowledge processing middleware as a systematic approach to integrating and organizing such processing, and argue that connecting processing components with streams provides essential support for steady and timely flows of information. DyKnow is a concrete and implemented instantiation of such middleware, providing support for stream reasoning at several levels. First, the formal kpl language allows the specification of streams connecting knowledge processes and the required properties of such streams. Second, chronicle recognition incrementally detects complex events from streams of more primitive events. Third, complex metric temporal formulas can be incrementally evaluated over streams of states. DyKnow and the stream reasoning techniques are described and motivated in the context of a UAV traffic monitoring application. [364] Fredrik Heintz, Jonas Kvarnstrm and Patrick Doherty. 2010. Stream-Based Middleware Support for Embedded Reasoning. In Proceedings of the AAAI Spring Symposium on Embedded Reasoning: Intelligence in Embedded Systems (ER). AAAI Press. ISBN: 978-157735458-1. For autonomous systems such as unmanned aerial vehicles to successfully perform complex missions, a great deal of embedded reasoning is required at varying levels of abstraction. In order to make use of diverse reasoning modules in such systems, issues of integration such as sensor data flow and information flow between such modules has to be taken into account. The DyKnow framework is a tool with a formal basis that pragmatically deals with many of the architectural issues which arise in such systems. This includes a systematic stream-based method for handling the sense-reasoning gap, caused by the wide difference in abstraction levels between the noisy data generally available from sensors and the symbolic, semantically meaningful information required by many high-level reasoning modules. DyKnow has proven to be quite robust and widely applicable to different aspects of hybrid software architectures for robotics.In this paper, we describe the DyKnow framework and show how it is integrated and used in unmanned aerial vehicle systems developed in our group. In particular, we focus on issues pertaining to the sense-reasoning gap and the symbol grounding problem and the use of DyKnow as a means of generating semantic structures representing situational awareness for such systems. We also discuss the use of DyKnow in the context of automated planning, in particular execution monitoring. [363] Mattias Krysander, Fredrik Heintz, Jacob Roll and Erik Frisk. 2010. FlexDx: A Reconfigurable Diagnosis Framework. Engineering applications of artificial intelligence, 23(8):1303–1313. Elsevier. DOI: 10.1016/j.engappai.2010.01.004. Detecting and isolating multiple faults is a computationally expensive task. It typically consists of computing a set of tests and then computing the diagnoses based on the test results. This paper describes FlexDx, a reconfigurable diagnosis framework which reduces the computational burden while retaining the isolation performance by only running a subset of all tests that is sufficient to find new conflicts. Tests in FlexDx are thresholded residuals used to indicate conflicts in the monitored system. Special attention is given to the issues introduced by a reconfigurable diagnosis framework. For example, tests are added and removed dynamically, tests are partially performed on historic data, and synchronous and asynchronous processing are combined. To handle these issues FlexDx has been implemented using DyKnow, a stream-based knowledge processing middleware framework. Concrete methods for each component in the FlexDx framework are presented. The complete approach is exemplified on a dynamic system which clearly illustrates the complexity of the problem and the computational gain of the proposed approach. [362] Fredrik Heintz, Jonas Kvarnstrm and Patrick Doherty. 2010. Stream-Based Reasoning Support for Autonomous Systems. In Proceedings of the 19th European Conference on Artificial Intelligence (ECAI). In series: Frontiers in Artificial Intelligence and Applications #215. IOS Press. ISBN: 978-1-60750-605-8. DOI: 10.3233/978-1-60750-606-5-183. For autonomous systems such as unmanned aerial vehicles to successfully perform complex missions, a great deal of embedded reasoning is required at varying levels of abstraction. To support the integration and use of diverse reasoning modules we have developed DyKnow, a stream-based knowledge processing middleware framework. By using streams, DyKnow captures the incremental nature of sensor data and supports the continuous reasoning necessary to react to rapid changes in the environment. DyKnow has a formal basis and pragmatically deals with many of the architectural issues which arise in autonomous systems. This includes a systematic stream-based method for handling the sense-reasoning gap, caused by the wide difference in abstraction levels between the noisy data generally available from sensors and the symbolic, semantically meaningful information required by many highlevel reasoning modules. As concrete examples, stream-based support for anchoring and planning are presented. [361] Fredrik Heintz and Patrick Doherty. 2010. Federated DyKnow, a Distributed Information Fusion System for Collaborative UAVs. In Proceedings of the 11th International Conference on Control, Automation, Robotics and Vision (ICARCV), pages 1063–1069. IEEE conference proceedings. ISBN: 978-1-4244-7814-9. DOI: 10.1109/ICARCV.2010.5707967. As unmanned aerial vehicle (UAV) applications are becoming more complex and covering larger physical areas there is an increasing need for multiple UAVs to cooperatively solve problems. To produce more complete and accurate information about the environment we present the DyKnow Federation framework for distributed fusion among collaborative UAVs. A federation is created and maintained using a multi-agent delegation framework which allows high-level specification and reasoning about resource bounded cooperative problem solving. When the federation is set up, local information is transparently shared between the agents according to specification. The work is presented in the context of a multi-UAV traffic monitoring scenario. [360] Jonas Kvarnstrm and Patrick Doherty. 2010. Automated Planning for Collaborative UAV Systems. In Proceedings of the 11th International Conference on Control, Automation, Robotics and Vision (ICARCV), pages 1078–1085. IEEE conference proceedings. ISBN: 978-1-4244-7813-2, 978-1-4244-7814-9. DOI: 10.1109/ICARCV.2010.5707969. IEEE Explore: http://ieeexplore.ieee.org/xpls/abs_all.... Mission planning for collaborative Unmanned Aircraft Systems (UAS:s) is a complex topic which involves trade-offs between the degree of centralization or decentralization required, the degree of abstraction in which plans are generated, and the degree to which such plans are distributed among participating UAS:s. In realistic environments such as those found in naturaland man-made catastrophes where emergency services personnelare involved, a certain degree of centralization and abstractionis necessary in order for those in charge to understand andeventually sign off on potential plans. It is also quite often thecase that unconstrained distribution of actions is inconsistentwith the loosely coupled interactions and dependencies whicharise between collaborating systems. In this article, we presenta new planning algorithm for collaborative UAS:s based oncombining ideas from forward chaining planning with partialorderplanning leading to a new hybrid partial order forwardchaining(POFC) framework which meets the requirements oncentralization, abstraction and distribution we find in realisticemergency services settings. [359] Per-Magnus Olsson, Jonas Kvarnstrm, Patrick Doherty, Oleg Burdakov and Kaj Holmberg. 2010. Generating UAV Communication Networks for Monitoring and Surveillance. In Proceedings of the 11th International Conference on Control, Automation, Robotics and Vision (ICARCV 2010), pages 1070–1077. IEEE conference proceedings. ISBN: 978-1-4244-7814-9. DOI: 10.1109/ICARCV.2010.5707968. An important use of unmanned aerial vehicles is surveillance of distant targets, where sensor information must quickly be transmitted back to a base station. In many cases, high uninterrupted bandwidth requires line-of-sight between sender and transmitter to minimize quality degradation. Communication range is typically limited, especially when smaller UAVs are used. Both problems can be solved by creating relay chains for surveillance of a single target, and relay trees for simultaneous surveillance of multiple targets. In this paper, we show how such chains and trees can be calculated. For relay chains we create a set of chains offering different trade-offs between the number of UAVs in the chain and the chain’s cost. We also show new results on how relay trees can be quickly calculated and then incrementally improved if necessary. Encouraging empirical results for improvement of relay trees are presented. [358] Hkan Warnquist, Jonas Kvarnstrm and Patrick Doherty. 2010. Iterative Bounding LAO*. In Helder Coelho, Rudi Studer and Mike Wooldridge, editors, ECAI 2010: 19th European Conference on Artificial Intelligence - Volume 215 Frontiers in Artificial Intelligence and Applications, pages 341–346. In series: Frontiers in Artificial Intelligence and Applications #215. IOS Press. ISBN: 978-1-60750-605-8, 978-1-60750-606-5. DOI: 10.3233/978-1-60750-606-5-341. Iterative Bounding LAO* is a new algorithm for epsilon- optimal probabilistic planning problems where an absorbing goal state should be reached at a minimum expected cost from a given initial state. The algorithm is based on the LAO* algorithm for finding optimal solutions in cyclic AND/OR graphs. The new algorithm uses two heuristics, one upper bound and one lower bound of the optimal cost. The search is guided by the lower bound as in LAO*, while the upper bound is used to prune search branches. The algorithm has a new mechanism for expanding search nodes, and while maintaining the error bounds, it may use weighted heuristics to reduce the size of the explored search space. In empirical tests on benchmark problems, Iterative Bounding LAO* expands fewer search nodes compared to state of the art RTDP variants that also use two-sided bounds. [357] Jonas Kvarnstrm. 2010. Planning for Loosely Coupled Agents using Partial Order Forward-Chaining. In Roland Bol, editor, The Swedish AI Society Workshop 2010, SAIS 2010, pages 45–54. In series: Linkping Electronic Conference Proceedings #48. Linkping University Electronic Press, Linkpings universitet. Fulltext: http://www.ep.liu.se/ecp/048/009/ecp1048... Partially ordered plan structures are highly suitable for centralized multi-agent planning, where plans should be minimally constrained in terms of precedence between actions performed by different agents. In many cases, however, any given agent will perform its own actions in strict sequence. We take advantage of this fact to develop a hybrid of temporal partial order planning and forward-chaining planning. A sequence of actions is constructed for each agent and linked to other agents' actions by a partially ordered precedence relation as required. When agents are not too tightly coupled, this structure enables the generation of partial but strong information about the state at the end of each agent's action sequence. Such state information can be effectively exploited during search. A prototype planner within this framework has been implemented, using precondition control formulas to guide the search process. [356] Patrick Doherty and Andrzej Szalas. 2010. On the Correctness of Rough-Set Based Approximate Reasoning. In M. Szczuka, M. Kryszkiewicz, S. Ramanna, R. Jensen, Q. Hu, editors, Proceedings of the 7th International Conference on Rough Sets and Current Trends in Computing (RSCTC), pages 327–336. In series: Lecture Notes in Computer Science #6086. Springer. ISBN: 978-3-642-13528-6. DOI: 10.1007/978-3-642-13529-3_35. There is a natural generalization of an indiscernibility relation used in rough set theory, where rather than partitioning the universe of discourse into indiscernibility classes, one can consider a covering of the universe by similarity-based neighborhoods with lower and upper approximations of relations defined via the neighborhoods. When taking this step, there is a need to tune approximate reasoning to the desired accuracy. We provide a framework for analyzing self-adaptive knowledge structures. We focus on studying the interaction between inputs and output concepts in approximate reasoning. The problems we address are: -given similarity relations modeling approximate concepts, what are similarity relations for the output concepts that guarantee correctness of reasoning? -assuming that output similarity relations lead to concepts which are not accurate enough, how can one tune input similarities? [355] Barbara Dunin-Keplicz, Linh Anh Nguyen and Andrzej Szalas. 2010. A Framework for Graded Beliefs, Goals and Intentions. Fundamenta Informaticae, 100(1-4):53–76. IOS Press. DOI: 10.3233/FI-2010-263. In natural language we often use graded concepts, reflecting different intensity degrees of certain features. Whenever such concepts appear in a given real-life context, they need to be appropriately expressed in its models. In this paper, we provide a framework which allows for extending the BGI model of agency by grading beliefs, goals and intentions. We concentrate on TEAMLOG [6, 7, 8, 9, 12] and provide a complexity-optimal decision method for its graded version TEAMLOG(K) by translating it into CPDLreg (propositional dynamic logic with converse and \"inclusion axioms\" characterized by regular languages). We also develop a tableau calculus which leads to the first EXPTIME (optimal) tableau decision procedure for CPDLreg. As CPDLreg is suitable for expressing complex properties of graded operators, the procedure can also be used as a decision tool for other multiagent formalisms. [354] Barbara Dunin-Keplicz, Linh Anh Nguyen and Andrzej Szalas. 2010. A Layered Rule-Based Architecture for Approximate Knowledge Fusion. COMPUTER SCIENCE AND INFORMATION SYSTEMS, 7(3):617–642. COMSIS CONSORTIUM. DOI: 10.2298/CSIS100209015D. In this paper we present a framework for fusing approximate knowledge obtained from various distributed, heterogenous knowledge sources. This issue is substantial in modeling multi-agent systems, where a group of loosely coupled heterogeneous agents cooperate in achieving a common goal. In paper [5] we have focused on defining general mechanism for knowledge fusion. Next, the techniques ensuring tractability of fusing knowledge expressed as a Horn subset of propositional dynamic logic were developed in [13,16]. Propositional logics may seem too weak to be useful in real-world applications. On the other hand, propositional languages may be viewed as sublanguages of first-order logics which serve as a natural tool to define concepts in the spirit of description logics [2]. These notions may be further used to define various ontologies, like e. g. those applicable in the Semantic Web. Taking this step, we propose a framework, in which our Horn subset of dynamic logic is combined with deductive database technology. This synthesis is formally implemented in the framework of HSPDL architecture. The resulting knowledge fusion rules are naturally applicable to real-world data. [353] Oleg Burdakov, Patrick Doherty, Kaj Holmberg, Jonas Kvarnstrm and Per-Magnus Olsson. 2010. Relay Positioning for Unmanned Aerial Vehicle Surveillance. The international journal of robotics research, 29(8):1069–1087. Sage Publications. DOI: 10.1177/0278364910369463. When unmanned aerial vehicles (UAVs) are used for surveillance, information must often be transmitted to a base station in real time. However, limited communication ranges and the common requirement of free line of sight may make direct transmissions from distant targets impossible. This problem can be solved using relay chains consisting of one or more intermediate relay UAVs. This leads to the problem of positioning such relays given known obstacles, while taking into account a possibly mission-specific quality measure. The maximum quality of a chain may depend strongly on the number of UAVs allocated. Therefore, it is desirable to either generate a chain of maximum quality given the available UAVs or allow a choice from a spectrum of Pareto-optimal chains corresponding to different trade-offs between the number of UAVs used and the resulting quality. In this article, we define several problem variations in a continuous three-dimensional setting. We show how sets of Pareto-optimal chains can be generated using graph search and present a new label-correcting algorithm generating such chains significantly more efficiently than the best-known algorithms in the literature. Finally, we present a new dual ascent algorithm with better performance for certain tasks and situations. [352] Barbara Dunin-Keplicz, Linh Anh Nguyen and Andrzej Szalas. 2010. Tractable approximate knowledge fusion using the Horn fragment of serial propositional dynamic logic. International Journal of Approximate Reasoning, 51(3):346–362. Elsevier. DOI: 10.1016/j.ijar.2009.11.002. In this paper we investigate a technique for fusing approximate knowledge obtained from distributed, heterogeneous information sources. This issue is substantial, e.g., in modeling multiagent systems, where a group of loosely coupled heterogeneous agents cooperate in achieving a common goal. Information exchange, leading ultimately to knowledge fusion, is a natural and vital ingredient of this process. We use a generalization of rough sets and relations [30], which depends on allowing arbitrary similarity relations. The starting point of this research is [6], where a framework for knowledge fusion in multiagent systems is introduced. Agents individual perceptual capabilities are represented by similarity relations, further aggregated to express joint capabilities of teams, This aggregation, expressing a shift from individual to social level of agents activity, has been formalized by means of dynamic logic. The approach of Doherty et al. (2007) [6] uses the full propositional dynamic logic, which does not guarantee tractability of reasoning. Our idea is to adapt the techniques of Nguyen [26-28] to provide an engine for tractable approximate database querying restricted to a Horn fragment of serial dynamic logic. We also show that the obtained formalism is quite powerful in applications. [351] Karolina Eliasson. 2010. A case-based approach to dialogue systems. Journal of experimental and theoretical artificial intelligence (Print), 22(1):23–51. Taylor & Francis. DOI: 10.1080/09528130902723708. We describe an approach to integrate dialogue management, machine-learning and action planning in a system for dialogue between a human and a robot. Case-based techniques are used because they permit life-long learning from experience and demand little prior knowledge and few static hand-written structures. This approach has been developed through the work on an experimental dialogue system, called CEDERIC, that is connected to an unmanned aerial vehicle (UAV). A single case base and case-based reasoning engine is used both for understanding and for planning actions by the UAV. Dialogue experiments both with experienced and novice users, where the users have solved tasks by dialogue with this system, showed very adequate success rates. [350] Fredrik slin. 2010. Evaluation of Hierarchical Temporal Memory in algorithmic trading. Student Thesis. 32 pages. ISRN: LIU-IDA/LITH-EX-G--10/005--SE. This thesis looks into how one could use Hierarchal Temporal Memory (HTM) networks to generate models that could be used as trading algorithms. The thesis begins with a brief introduction to algorithmic trading and commonly used concepts when developing trading algorithms. The thesis then proceeds to explain what an HTM is and how it works. To explore whether an HTM could be used to generate models that could be used as trading algorithms, the thesis conducts a series of experiments. The goal of the experiments is to iteratively optimize the settings for an HTM and try to generate a model that when used as a trading algorithm would have more profitable trades than losing trades. The setup of the experiments is to train an HTM to predict if it is a good time to buy some shares in a security and hold them for a fixed time before selling them again. A fair amount of the models generated during the experiments was profitable on data the model have never seen before, therefore the author concludes that it is possible to train an HTM so it can be used as a profitable trading algorithm. [349] Fredrik Heintz, Jonas Kvarnstrm and Patrick Doherty. 2010. Bridging the sense-reasoning gap: DyKnow - Stream-based middleware for knowledge processing. Advanced Engineering Informatics, 24(1):14–26. Elsevier. DOI: 10.1016/j.aei.2009.08.007. Engineering autonomous agents that display rational and goal-directed behavior in dynamic physical environments requires a steady flow of information from sensors to high-level reasoning components. However, while sensors tend to generate noisy and incomplete quantitative data, reasoning often requires crisp symbolic knowledge. The gap between sensing and reasoning is quite wide, and cannot in general be bridged in a single step. Instead, this task requires a more general approach to integrating and organizing multiple forms of information and knowledge processing on different levels of abstraction in a structured and principled manner. We propose knowledge processing middleware as a systematic approach to organizing such processing. Desirable properties are presented and motivated. We argue that a declarative stream-based system is appropriate for the required functionality and present DyKnow, a concrete implemented instantiation of stream-based knowledge processing middleware with a formal semantics. Several types of knowledge processes are defined and motivated in the context of a UAV traffic monitoring application. In the implemented application, DyKnow is used to incrementally bridge the sense-reasoning gap and generate partial logical models of the environment over which metric temporal logical formulas are evaluated. Using such formulas, hypotheses are formed and validated about the type of vehicles being observed. DyKnow is also used to generate event streams representing for example changes in qualitative spatial relations, which are used to detect traffic violations expressed as declarative chronicles. [348] Oleg Burdakov, Patrick Doherty, Kaj Holmberg, Jonas Kvarnstrm and Per-Magnus Olsson. 2010. Positioning Unmanned Aerial Vehicles As Communication Relays for Surveillance Tasks. In J. Trinkle, Y. Matsuoka and J.A. Castellanos, editors, Robotics: Science and Systems V, pages 257–264. MIT Press. ISBN: 978-0-262-51463-7. find book at a swedish library/hitta boken i ett svenskt bibliotek: http://libris.kb.se/bib/12536749 Link to publication: http://www.roboticsproceedings.org/rss05... When unmanned aerial vehicles (UAVs) are used to survey distant targets, it is important to transmit sensor information back to a base station. As this communication often requires high uninterrupted bandwidth, the surveying UAV often needs afree line-of-sight to the base station, which can be problematic in urban or mountainous areas. Communication ranges may also belimited, especially for smaller UAVs. Though both problems can be solved through the use of relay chains consisting of one or more intermediate relay UAVs, this leads to a new problem: Where should relays be placed for optimum performance? We present two new algorithms capable of generating such relay chains, one being a dual ascent algorithm and the other a modification of the Bellman-Ford algorithm. As the priorities between the numberof hops in the relay chain and the cost of the chain may vary, wecalculate chains of different lengths and costs and let the ground operator choose between them. Several different formulations for edge costs are presented. In our test cases, both algorithms are substantially faster than an optimized version of the original Bellman-Ford algorithm, which is used for comparison. 2009 [347] Mikael Nilsson. 2009. Spannerar och spannervgar. Student Thesis. 126 pages. ISRN: -. In this Master Thesis the possibility to efficiently divide a graph into spanner islands is examined. Spanner islands are islands of the graph that fulfill the spanner condition, that the distance between two nodes via the edges in the graph cannot be too far, regulated by the stretch constant, compared to the Euclidian distance between them. In the resulting division the least number of nodes connecting to other islands is sought-after. Different heuristics are evaluated with the conclusion that for dense graphs a heuristic using MAX-FLOW to divide problematic nodes gives the best result whereas for sparse graphs a heuristic using the single-link clustering method performs best. The problem of finding a spanner path, a path fulfilling the spanner condition, between two nodes is also investigated. The problem is proven to be NP-complete for a graph of size n if the spanner constant is greater than n^(1+1/k)*k^0.5 for some integer k. An algorithm with complexity O(2^(0.822n)) is given. A special type of graph where all the nodes are located on integer locations along the real line is investigated. An algorithm to solve this problem is presented with a complexity of O(2^((c*log n)^2))), where c is a constant depending only on the spanner constant. For instance, the complexity O(2^((5.32*log n)^2))) can be reached for stretch 1.5. [346] Barbara Dunin-Keplicz, Linh Anh Nguyen and Andrzej Szalas. 2009. Fusing Approximate Knowledge from Distributed Sources. In Proceedings of the 3rd International Symposium on Intelligent Distributed Computing (IDC), pages 75–86. In series: Studies in Computational Intelligence #237. Springer Berlin/Heidelberg. ISBN: 978-3-642-03213-4, 978-3-642-26930-1. DOI: 10.1007/978-3-642-03214-1_8. In this paper we investigate a technique for fusing approximate knowledge obtained from distributed, heterogeneous information sources. We use a generalization of rough sets and relations [14], which depends on allowing arbitrary similarity relations. The starting point of this research is [2], where a framework for knowledge fusion in multi-agent systems is introduced. Agent’s individual perceptual capabilities are represented by similarity relations, further aggregated to express joint capabilities of teams. This aggregation, allowing a shift from individual to social level, has been formalized by means of dynamic logic. The approach of [2] uses the full propositional dynamic logic, not guaranteeing the tractability of reasoning. Therefore the results of [11, 12, 13] are adapted to provide a technical engine for tractable approximate database querying restricted to a Horn fragment of serial PDL. We also show that the obtained formalism is quite powerful in applications. [345] Linh Anh Nguyen and Andrzej Szalas. 2009. Checking Consistency of an ABox w.r.t. Global Assumptions in PDL*. In Proceedings of the 18th Concurrency, Specification and Programming Workshop (CS&P), pages 431–442. [344] Linh Anh Nguyen and Andrzej Szalas. 2009. An Optimal Tableau Decision Procedure for Converse-PDL. In Proceedings of the 1st International Conference on Knowlegde and Systems Engineering (KSE), pages 207–214. IEEE Computer Society. ISBN: 978-1-4244-5086-2. DOI: 10.1109/KSE.2009.12. We give a novel tableau calculus and an optimal (EXPTIME) tableau decision procedure based on the calculus for the satisfiability problem of propositional dynamic logic with converse. Our decision procedure is formulated with global caching and can be implemented together with useful optimization techniques. [343] Cyrille Berger. 2009. Perception de la gomtrie de l'environment pour la navigation autonome. PhD Thesis. Universit de Toulouse. 164 pages. Le but de la recherche en robotique mobile est de donner aux robots la capacité d'accomplir des missions dans un environnement qui n'est pas parfaitement connu. Mission, qui consiste en l'exécution d'un certain nombre d'actions élémentaires (déplacement, manipulation d'objets...) et qui nécessite une localisation précise, ainsi que la construction d'un bon modèle géométrique de l'environnement, a partir de l'exploitation de ses propres capteurs, des capteurs externes, de l'information provenant d'autres robots et de modèle existant, par exemple d'un système d'information géographique. L'information commune est la géométrie de l'environnement. La première partie du manuscrit couvre les différentes méthodes d'extraction de l'information géométrique. La seconde partie présente la création d'un modèle géométrique en utilisant un graphe, ainsi qu'une méthode pour extraire de l'information du graphe et permettre au robot de se localiser dans l'environnement. [342] Teresa Vidal-Calleja, Cyrille Berger, Joan Sol and Simon Lacroix. 2009. Environment Modeling for Cooperative Aerial/Ground Robotic Systems. In Proceedings of the 14th International Symposium on Robotics Research (ISRR), pages 681–696. In series: Springer Tracts in Advanced Robotics #70. Springer. ISBN: 978-3-642-19456-6. DOI: 10.1007/978-3-642-19457-3_40. This paper addresses the cooperative localization and visual mapping problem for multiple aerial and ground robots.We propose the use of heterogeneous visual landmarks, points and line segments. A large-scale SLAM algorithm is generalized to manage multiple robots, in which a global graph maintains the topological relationships between a series of local sub-maps built by the different robots. Only single camera setups are considered: in order to achieve undelayed initialization, we present a novel parametrization for lines based on anchored Plücker coordinates, to which we add extensible endpoints to enhance their representativeness. The built maps combine such lines with 3D points parametrized in inverse-depth. The overall approach is evaluated with real-data taken with a helicopter and a ground rover in an abandoned village. [341] Teresa Vidal-Calleja, Cyrille Berger and Simon Lacroix. 2009. Event-driven loop closure in multi-robot mapping. In Proceedings of the IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), pages 1535–1540. IEEE conference proceedings. ISBN: 978-1-4244-3803-7. DOI: 10.1109/IROS.2009.5354335. A large-scale mapping approach is combined with multiple robots events to achieve cooperative mapping. The mapping approach used is based on hierarchical SLAM -global level and local maps-, which is generalized for the multi-robot case. In particular, the consequences of multi-robot loop closing events (common landmarks detection and relative pose measurement between robots) are analyzed and managed at a global level. We present simulation results for each of these events using aerial and ground robots, and experimental results obtained with ground robots. [340] Dov Gabbay and Andrzej Szalas. 2009. Annotation Theories over Finite Graphs. Studia Logica: An International Journal for Symbolic Logic, 93(2-3):147–180. Springer. DOI: 10.1007/s11225-009-9220-3. In the current paper we consider theories with vocabulary containing a number of binary and unary relation symbols. Binary relation symbols represent labeled edges of a graph and unary relations represent unique annotations of the graph’s nodes. Such theories, which we call annotation theories, can be used in many applications, including the formalization of argumentation, approximate reasoning, semantics of logic programs, graph coloring, etc. We address a number of problems related to annotation theories over finite models, including satisfiability, querying problem, specification of preferred models and model checking problem. We show that most of considered problems are NPTime- or co-NPTime-complete. In order to reduce the complexity for particular theories, we use second-order quantifier elimination. To our best knowledge none of existing methods works in the case of annotation theories. We then provide a new second-order quantifier elimination method for stratified theories, which is successful in the considered cases. The new result subsumes many other results, including those of [2, 28, 21]. [339] Anna Pernestl, Hkan Warnquist and Mattias Nyberg. 2009. Modeling and Troubleshooting with Interventions Applied to an Auxiliary Truck Braking System. In Proceedings of the 2nd IFAC Workshop on Dependable Control of Discrete Systems (DCDS), pages 251–256. ISBN: 978-390266144-9. DOI: 10.3182/20090610-3-IT-4004.00048. We consider computer assisted troubleshooting of complex systems, where the objective is to identify the cause of a failure and repair the system at as low expected cost as possible. Three main challenges are: the need for disassembling the system during troubleshooting, the difficulty to verify that the system is fault free, and the dependencies in between components and observations. We present a method that can return a response anytime, which allows us to obtain the best result given the available time. The work is based on a case study of an auxiliary braking system of a modern truck. We highlight practical issues related to model building and troubleshooting in a real environment. [338] Aida Vitoria, Jan Maluszynski and Andrzej Szalas. 2009. Modelling and Reasoning with Paraconsistent Rough Sets. Fundamenta Informaticae, 97(4):405–438. DOI: 10.3233/FI-2009-209. We present a language for defining paraconsistent rough sets and reasoning about them. Our framework relates and brings together two major fields: rough sets [23] and paraconsistent logic programming [9]. To model inconsistent and incomplete information we use a four-valued logic. The language discussed in this paper is based on ideas of our previous work [21, 32, 22] developing a four-valued framework for rough sets. In this approach membership function, set containment and set operations are four-valued, where logical values are t (true), f (false), i (inconsistent) and u (unknown). We investigate properties of paraconsistent rough sets as well as develop a paraconsistent rule language, providing basic computational machinery for our approach. [337] Anna Pernestl, Mattias Nyberg and Hkan Warnquist. 2009. Modeling and Efficient Inference for Troubleshooting Automotive Systems. Technical Report. In series: LiTH-ISY-R #2921. Linkpings universitet. We consider computer assisted troubleshooting of automotive vehicles, where the objective is to repair the vehicle at as low expected cost as possible.The work has three main contributions: a troubleshooting method that applies to troubleshooting in real environments, the discussion on practical issues in modeling for troubleshooting, and the efficient probability computations.The work is based on a case study of an auxiliary braking system of a modern truck.We apply a decision theoretic approach, consisting of a planner and a diagnoser.Two main challenges in troubleshooting automotive vehicles are the need for disassembling the vehicle during troubleshooting to access parts to repair, and the difficulty to verify that the vehicle is fault free. These facts lead to that probabilities for faults and for future observations must be computed for a system that has been subject to external interventions that cause changes the dependency structure. The probability computations are further complicated due to the mixture of instantaneous and non-instantaneous dependencies.To compute the probabilities, we develop a method based on an algorithm, updateBN, that updates a static BN to account for the external interventions. [336] Hkan Warnquist, Jonas Kvarnstrm and Patrick Doherty. 2009. Planning as Heuristic Search for Incremental Fault Diagnosis and Repair. In Proceedings of the Scheduling and Planning Applications Workshop (SPARK) at the 19th International Conference on Automated Planning and Scheduling (ICAPS). In this paper we study the problem of incremental fault diagnosis and repair of mechatronic systems where the task is to choose actions such that the expected cost of repair is minimal. This is done by interleaving acting with the generation of partial conditional plans used to decide the next action. A diagnostic model based on Bayesian Networks is used to update the current belief state after each action. The planner uses a simplified version of this model to update predicted belief states. We have tested the approach in the domain of troubleshooting heavy vehicles. Experiments show that a simplified model for planning improves performance when troubleshooting with limited time. [335] Hkan Warnquist, Anna Pernestl and Mattias Nyberg. 2009. Anytime Near-Optimal Troubleshooting Applied to a Auxiliary Truck Braking System. In Proceedings of the 7th IFAC Symposium on Fault Detection, Supervision and Safety of Technical Processes, pages 1306–1311. ISBN: 978-3-902661-46-3. DOI: 10.3182/20090630-4-ES-2003.00212. We consider computer assisted troubleshooting of complex systems, for example of a vehicle at a workshop. The objective is to identify the cause of a failure and repair a system at as low expected cost as possible. Three main challenges are: the need for disassembling the system during troubleshooting, the difficulty to verify that the system is fault free, and the dependencies in between components and observations. We present a method that can return a response anytime, which allows us to obtain the best result given the available time. The work is based on a case study of an auxiliary braking system of a modern truck. We highlight practical issues related to model building and troubleshooting in a real environment. [334] Oleg Burdakov, Kaj Holmberg, Patrick Doherty and Per-Magnus Olsson. 2009. Optimal placement of communications relay nodes. Technical Report. In series: LiTH-MAT-R #2009:3. Linkpings universitet. 21 pages. We consider a constrained optimization problem with mixed integer and real variables. It models optimal placement of communications relay nodes in the presence of obstacles. This problem is widely encountered, for instance, in robotics, where it is required to survey some target located in one point and convey the gathered information back to a base station located in another point. One or more unmanned aerial or ground vehicles (UAVs or UGVs) can be used for this purpose as communications relays. The decision variables are the number of unmanned vehicles (UVs) and the UV positions. The objective function is assumed to access the placement quality. We suggest one instance of such a function which is more suitable for accessing UAV placement. The constraints are determined by, firstly, a free line of sight requirement for every consecutive pair in the chain and, secondly, a limited communication range. Because of these requirements, our constrained optimization problem is a difficult multi-extremal problem for any fixed number of UVs. Moreover, the feasible set of real variables is typically disjoint. We present an approach that allows us to efficiently find a practically acceptable approximation to a global minimum in the problem of optimal placement of communications relay nodes. It is based on a spatial discretization with a subsequent reduction to a shortest path problem. The case of a restricted number of available UVs is also considered here. We introduce two label correcting algorithms which are able to take advantage of using some peculiarities of the resulting restricted shortest path problem. The algorithms produce a Pareto solution to the two-objective problem of minimizing the path cost and the number of hops. We justify their correctness. The presented results of numerical 3D experiments show that our algorithms are superior to the conventional Bellman-Ford algorithm tailored to solving this problem. [333] Patrick Doherty and Jonas Kvarnstrm. 2009. Temporal Action Logics. In V. Lifschitz, F. van Harmelen, and F. Porter, editors, Handbook of Knowledge Representation, pages 709–757. In series: Foundations of Artificial Intelligence #3. Elsevier. ISBN: 978-0-444-52211-5. DOI: 10.1016/S1574-6526(07)03018-0. find book at a swedish library/hitta boken i ett svenskt bibliotek: http://libris.kb.se/hitlist?d=libris&q=9... The study of frameworks and formalisms for reasoning about action and change [67, 58, 61, 65, 70, 3, 57] has been central to the knowledge representation field almost from the inception of Artificial Intelligence as a general field of research [52, 56]. The phrase “Temporal Action Logics” represents a class of logics for reasoning about action and change that evolved from Sandewall’s book on Features and Fluents [61] and owes much to this ambitious project. There are essentially three major parts to Sandewall’s work. He first developed a narrative-based logical framework for specifying agent behavior in terms of action scenarios. The logical framework is state-based and uses explicit time structures. He then developed a formal framework for assessing the correctness (soundness and completeness) of logics for reasoning about action and change relative to a set of well-defined intended conclusions, where reasoning problems were classified according to their ontological or epistemological characteristics. Finally, he proposed a number of logics defined semantically in terms of definitions of preferential entailment1 and assessed their correctness using his assessment framework. [332] Martin Magnusson, David Landn and Patrick Doherty. 2009. Logical Agents that Plan, Execute, and Monitor Communication. In Proceedings of the 2nd Workshop on Logic and the Simulation of Interaction and Reasoning (LSIR-2). [331] Martin Magnusson and Patrick Doherty. 2009. Planning Speech Acts in a Logic of Action and Change. In Fredrik Heintz and Jonas Kvarnström, editors, The Swedish AI Society Workshop 2009, SAIS 2009, pages 39–48. In series: Linkping Electronic Conference Proceedings #35. Linkping University Electronic Press, Linkpings universitet. Fulltext: http://www.ep.liu.se/ecp/035/008/ecp0935... Cooperation is a complex task that necessarily involves communication and reasoning about others’ intentions and beliefs. Multi-agent communication languages aid designers of cooperating robots through standardized speech acts, sometimes including a formal semantics. But a more direct approach would be to have the robots plan both regular and communicative actions themselves. We show how two robots with heterogeneous capabilities can autonomously decide to cooperate when faced with a task that would otherwise be impossible. Request and inform speech acts are formulated in the same first-order logic of action and change as is used for regular actions. This is made possible by treating the contents of communicative actions as quoted formulas of the same language. The robot agents then use a natural deduction theorem prover to generate cooperative plans for an example scenario by reasoning directly with the axioms of the theory. [330] Patrick Doherty, Jonas Kvarnstrm and Fredrik Heintz. 2009. A Temporal Logic-based Planning and Execution Monitoring Framework for Unmanned Aircraft Systems. Autonomous Agents and Multi-Agent Systems, 19(3):332–377. Springer. DOI: 10.1007/s10458-009-9079-8. Research with autonomous unmanned aircraft systems is reaching a new degree of sophistication where targeted missions require complex types of deliberative capability integrated in a practical manner in such systems. Due to these pragmatic constraints, integration is just as important as theoretical and applied work in developing the actual deliberative functionalities. In this article, we present a temporal logic-based task planning and execution monitoring framework and its integration into a fully deployed rotor-based unmanned aircraft system developed in our laboratory. We use a very challenging emergency services application involving body identification and supply delivery as a vehicle for showing the potential use of such a framework in real-world applications. TALplanner, a temporal logic-based task planner, is used to generate mission plans. Building further on the use of TAL (Temporal Action Logic), we show how knowledge gathered from the appropriate sensors during plan execution can be used to create state structures, incrementally building a partial logical model representing the actual development of the system and its environment over time. We then show how formulas in the same logic can be used to specify the desired behavior of the system and its environment and how violations of such formulas can be detected in a timely manner in an execution monitor subsystem. The pervasive use of logic throughout the higher level deliberative layers of the system architecture provides a solid shared declarative semantics that facilitates the transfer of knowledge between different modules. [329] Fredrik Heintz, Jonas Kvarnstrm and Patrick Doherty. 2009. Stream Reasoning in DyKnow: A Knowledge Processing Middleware System. In Proceedings of the Stream Reasoning Workshop. In series: CEUR Workshop Proceedings #466. M. Jeusfeld c/o Redaktion Sun SITE, Informatik V, RWTH Aachen. The information available to modern autonomous systems is often in the form of streams. As the number of sensors and other stream sources increases there is a growing need for incremental reasoning about the incomplete content of sets of streams in order to draw relevant conclusions and react to new situations as quickly as possible. To act rationally, autonomous agents often depend on high level reasoning components that require crisp, symbolic knowledge about the environment. Extensive processing at many levels of abstraction is required to generate such knowledge from noisy, incomplete and quantitative sensor data. We define knowledge processing middleware as a systematic approach to integrating and organizing such processing, and argue that connecting processing components with streams provides essential support for steady and timely flows of information. DyKnow is a concrete and implemented instantiation of such middleware, providing support for stream reasoning at several levels. First, the formal KPL language allows the specification of streams connecting knowledge processes and the required properties of such streams. Second, chronicle recognition incrementally detects complex events from streams of more primitive events. Third, complex metric temporal formulas can be incrementally evaluated over streams of states. DyKnow and the stream reasoning techniques are described and motivated in the context of a UAV traffic monitoring application. [328] Fredrik Heintz and Jonas Kvarnstrm. 2009. Proceedings of the Swedish AI Society Workshop 2009. Conference Proceedings. In series: Linkping Electronic Conference Proceedings #35. Linkping University Electronic Press, Linkpings universitet. 65 pages. Link to Book: http://www.ep.liu.se/ecp/035/ [327] Andrzej Szalas and Alicja Szalas. 2009. Paraconsistent Reasoning with Words. In Aspects of Natural Language Processing: Essays Dedicated to Leonard Bolc on the Occasion of His 75th Birthday, pages 43–58. In series: Lecture Notes in Computer Science #5070. Springer. ISBN: 978-3-642-04734-3. DOI: 10.1007/978-3-642-04735-0_2. find book at a swedish library/hitta boken i ett svenskt bibliotek: http://libris.kb.se/bib/11741557 Fuzzy logics are one of the most frequent approaches to model uncertainty and vagueness. In the case of fuzzy modeling, degrees of belief and disbelief sum up to 1, which causes problems in modeling the lack of knowledge and inconsistency. Therefore, so called paraconsistent intuitionistic fuzzy sets have been introduced, where the degrees of belief and disbelief are not required to sum up to 1. The situation when this sum is smaller than 1 reflects the lack of knowledge and its value greater than 1 models inconsistency. In many applications there is a strong need to guide and interpret fuzzy-like reasoning using qualitative approaches. To achieve this goal in the presence of uncertainty, lack of knowledge and inconsistency, we provide a framework for qualitative interpretation of the results of fuzzy-like reasoning by labeling numbers with words, like true, false, inconsistent, unknown, reflecting truth values of a suitable, usually finitely valued logical formalism. [326] Andrzej Szalas and Dov Gabbay. 2009. Voting by Eliminating Quantifiers. Studia Logica: An International Journal for Symbolic Logic, 92(3):365–379. Springer. DOI: 10.1007/s11225-009-9200-7. Mathematical theory of voting and social choice has attracted much attention. In the general setting one can view social choice as a method of aggregating individual, often conflicting preferences and making a choice that is the best compromise. How preferences are expressed and what is the “best compromise” varies and heavily depends on a particular situation. The method we propose in this paper depends on expressing individual preferences of voters and specifying properties of the resulting ranking by means of first-order formulas. Then, as a technical tool, we use methods of second-order quantifier elimination to analyze and compute results of voting. We show how to specify voting, how to compute resulting rankings and how to verify voting protocols. [325] Andrzej Szalas and Linh Anh Nguyen. 2009. EXPTIME Tableaux for Checking Satisfiability of a Knowledge Base in the Description Logic ALC. In Ngoc Thanh; Kowalczyk, Ryszard; Chen, Shyi-Ming, editors, Proceedings of the 1st International Conference on Computational Collective Intelligence - Semantic Web, Social Networks & Multiagent Systems (ICCCI), pages 437–448. In series: Lecture Notes in Artificial Intelligence #5796. Springer. ISBN: 978-3-642-04440-3, 978-3-642-04441-0. DOI: 10.1007/978-3-642-04441-0_38. We give the first ExpTime (optimal) tableau decision procedure for checking satisfiability of a knowledge base in the description logic ALC, not based on transformation that encodes ABoxes by nominals or terminology axioms. Our procedure can be implemented as an extension of the highly optimized tableau prover TGC [12] to obtain an efficient program for the mentioned satisfiability problem. [324] Martin Magnusson, Jonas Kvarnstrm and Patrick Doherty. 2009. Abductive Reasoning with Filtered Circumscription. In Proceedings of the IJCAI-09 Workshop on Nonmonotonic Reasoning, Action and Change (NRAC). UTSePress. ISBN: 978-0-9802840-7-2. For logical artificial intelligence to be truly useful,its methods must scale to problems of realistic size.An interruptible algorithm enables a logical agentto act in a timely manner to the best of its knowledge,given its reasoning so far. This seems necessaryto avoid analysis paralysis, trying to thinkof every potentiality, however unlikely, beforehand.These considerations prompt us to look for alternativereasoning mechanisms for filtered circumscription,a nonmonotonic reasoning formalism usede.g. by Temporal Action Logic and Event Calculus.We generalize Ginsberg’s circumscriptive theoremprover and describe an interruptible theoremprover based on abduction that has been used tounify planning and reasoning in a logical agent architecture. [323] Fredrik Heintz, Jonas Kvarnstrm and Patrick Doherty. 2009. A Stream-Based Hierarchical Anchoring Framework. In Proceedings of the IEEE/RSJ International Conference on Intelligent RObots and Systems (IROS). IEEE conference proceedings. ISBN: 978-1-4244-3803-7. DOI: 10.1109/IROS.2009.5354372. IEEE Xplore: http://ieeexplore.ieee.org/stamp/stamp.j... [322] M. Wiggberg and Peter Dalenius. 2009. Bridges and problem solving: Swedish engineering students' conceptions of engineering in 2007. In Proceedings of the 1st International Conference on Computer Supported Education (CSEDU), pages 5–12. ISBN: 978-989-8111-82-1. Swedish engineering students conceptions of engineering is investigated by a large nation-wide study in ten Swedish higher education institutions. Based on data from surveys and interviews, categories and top-lists, a picture of students conceptions of engineering is presented. Students conceptions of engineering, are somewhat divergent, but dealing with problems and their solutions and creativity are identified as core concepts. The survey data is in general more varied and deals with somewhat different kinds of terms. When explicitly asking for five engineering terms, as in the survey, a broader picture arises including terms, or concepts, denoting how students think of engineering and work in a more personal way. For example, words like hard work, stressful, challenging, interesting, and fun are used. On the other hand, it seems like the interviewed students tried to give more general answers that were not always connected to their personal experiences. Knowledge on students conceptions of engineering is essential for practitioners in engineering education. By information on students conceptions, the teaching can approach students at their particular mindset of the engineering field. Program managers with responsibility for design of engineering programs would also benefit using information on students conceptions of engineering. Courses could be motivated and contextualized in order to connect with the students. Recruitment officers would also have an easier time marketing why people should chose the engineering track. [321] Linh Anh Nguyen and Andrzej Szalas. 2009. A tableau calculus for regular grammar logics with converse. In Proceedings of the 22nd International Conference on Automated Deduction (CADE), pages 421–436. In series: Lecture Notes in Artificial Intelligence #5663. Springer. ISBN: 978-364202958-5. DOI: 10.1007/978-3-642-02959-2_31. We give a sound and complete tableau calculus for deciding the general satisfiability problem of regular grammar logics with converse (REG c logics). Tableaux of our calculus are defined as \"and-or\" graphs with global caching. Our calculus extends the tableau calculus for regular grammar logics given by Goré and Nguyen [11] by using a cut rule and existential automaton-modal operators to deal with converse. We use it to develop an ExpTime (optimal) tableau decision procedure for the general satisfiability problem of REG c logics. We also briefly discuss optimizations for the procedure. [320] Gianpaolo Conte and Patrick Doherty. 2009. Vision-Based Unmanned Aerial Vehicle Navigation Using Geo-Referenced Information. EURASIP Journal on Advances in Signal Processing, 2009(387308):1–18. Hindawi Publishing Corporation. DOI: 10.1155/2009/387308. This paper investigates the possibility of augmenting an Unmanned Aerial Vehicle (UAV) navigation system with a passive video camera in order to cope with long-term GPS outages. The paper proposes a vision-based navigation architecture which combines inertial sensors, visual odometry, and registration of the on-board video to a geo-referenced aerial image. The vision-aided navigation system developed is capable of providing high-rate and drift-free state estimation for UAV autonomous navigation without the GPS system. Due to the use of image-to-map registration for absolute position calculation, drift-free position performance depends on the structural characteristics of the terrain. Experimental evaluation of the approach based on offline flight data is provided. In addition the architecture proposed has been implemented on-board an experimental UAV helicopter platform and tested during vision-based autonomous flights. [319] Gianpaolo Conte. 2009. Vision-Based Localization and Guidance for Unmanned Aerial Vehicles. PhD Thesis. In series: Linkping Studies in Science and Technology. Dissertations #1260. Linkping University Electronic Press. 174 pages. ISBN: 978-91-7393-603-3. The thesis has been developed as part of the requirements for a PhD degree at the Artificial Intelligence and Integrated Computer System division (AIICS) in the Department of Computer and Information Sciences at Linköping University.The work focuses on issues related to Unmanned Aerial Vehicle (UAV) navigation, in particular in the areas of guidance and vision-based autonomous flight in situations of short and long term GPS outage.The thesis is divided into two parts. The first part presents a helicopter simulator and a path following control mode developed and implemented on an experimental helicopter platform. The second part presents an approach to the problem of vision-based state estimation for autonomous aerial platforms which makes use of geo-referenced images for localization purposes. The problem of vision-based landing is also addressed with emphasis on fusion between inertial sensors and video camera using an artificial landing pad as reference pattern. In the last chapter, a solution to a vision-based ground object geo-location problem using a fixed-wing micro aerial vehicle platform is presented.The helicopter guidance and vision-based navigation methods developed in the thesis have been implemented and tested in real flight-tests using a Yamaha Rmax helicopter. Extensive experimental flight-test results are presented. [318] Tommy Persson. 2009. Evaluating the use of DyKnow in multi-UAV traffic monitoring applications. Student Thesis. 75 pages. ISRN: LIU-IDA/LITH-EX-A--09/019--SE. This Master’s thesis describes an evaluation of the stream-based knowledge pro-cessing middleware framework DyKnow in multi-UAV traffic monitoring applica-tions performed at Saab Aerosystems. The purpose of DyKnow is “to providegeneric and well-structured software support for the processes involved in gen-erating state, object, and event abstractions about the environments of complexsystems.\" It does this by providing the concepts of streams, sources, computa-tional units (CUs), entity frames and chronicles.This evaluation is divided into three parts: A general quality evaluation ofDyKnow using the ISO 9126-1 quality model, a discussion of a series of questionsregarding the specific use and functionality of DyKnow and last, a performanceevaluation. To perform parts of this evaluation, a test application implementinga traffic monitoring scenario was developed using DyKnow and the Java AgentDEvelopment Framework (JADE).The quality evaluation shows that while DyKnow suffers on the usability side,the suitability, accuracy and interoperability were all given high marks.The results of the performance evaluation high-lights the factors that affect thememory and CPU requirements of DyKnow. It is shown that the most significantfactor in the demand placed on the CPU is the number of CUs and streams. Italso shows that DyKnow may suffer dataloss and severe slowdown if the CPU istoo heavily utilized. However, a reasonably sized DyKnow application, such as thescenario implemented in this report, should run without problems on systems atleast half as fast as the one used in the tests. [317] Fredrik Heintz. 2009. DyKnow: A Stream-Based Knowledge Processing Middleware Framework. PhD Thesis. In series: Linkping Studies in Science and Technology. Dissertations #1240. Linkping University Electronic Press. 258 pages. ISBN: 978–91–7393–696–5. As robotic systems become more and more advanced the need to integrate existing deliberative functionalities such as chronicle recognition, motion planning, task planning, and execution monitoring increases. To integrate such functionalities into a coherent system it is necessary to reconcile the different formalisms used by the functionalities to represent information and knowledge about the world. To construct and integrate these representations and maintain a correlation between them and the environment it is necessary to extract information and knowledge from data collected by sensors. However, deliberative functionalities tend to assume symbolic and crisp knowledge about the current state of the world while the information extracted from sensors often is noisy and incomplete quantitative data on a much lower level of abstraction. There is a wide gap between the information about the world normally acquired through sensing and the information that is assumed to be available for reasoning about the world.As physical autonomous systems grow in scope and complexity, bridging the gap in an ad-hoc manner becomes impractical and inefficient. Instead a principled and systematic approach to closing the sensereasoning gap is needed. At the same time, a systematic solution has to be sufficiently flexible to accommodate a wide range of components with highly varying demands. We therefore introduce the concept of knowledge processing middleware for a principled and systematic software framework for bridging the gap between sensing and reasoning in a physical agent. A set of requirements that all such middleware should satisfy is also described.A stream-based knowledge processing middleware framework called DyKnow is then presented. Due to the need for incremental refinement of information at different levels of abstraction, computations and processes within the stream-based knowledge processing framework are modeled as active and sustained knowledge processes working on and producing streams. DyKnow supports the generation of partial and context dependent stream-based representations of past, current, and potential future states at many levels of abstraction in a timely manner.To show the versatility and utility of DyKnow two symbolic reasoning engines are integrated into Dy-Know. The first reasoning engine is a metric temporal logical progression engine. Its integration is made possible by extending DyKnow with a state generation mechanism to generate state sequences over which temporal logical formulas can be progressed. The second reasoning engine is a chronicle recognition engine for recognizing complex events such as traffic situations. The integration is facilitated by extending DyKnow with support for anchoring symbolic object identifiers to sensor data in order to collect information about physical objects using the available sensors. By integrating these reasoning engines into DyKnow, they can be used by any knowledge processing application. Each integration therefore extends the capability of DyKnow and increases its applicability.To show that DyKnow also has a potential for multi-agent knowledge processing, an extension is presented which allows agents to federate parts of their local DyKnow instances to share information and knowledge.Finally, it is shown how DyKnow provides support for the functionalities on the different levels in the JDL Data Fusion Model, which is the de facto standard functional model for fusion applications. The focus is not on individual fusion techniques, but rather on an infrastructure that permits the use of many different fusion techniques in a unified framework.The main conclusion of this thesis is that the DyKnow knowledge processing middleware framework provides appropriate support for bridging the sense-reasoning gap in a physical agent. This conclusion is drawn from the fact that DyKnow has successfully been used to integrate different reasoning engines into complex unmanned aerial vehicle (UAV) applications and that it satisfies all the stated requirements for knowledge processing middleware to a significant degree. 2008 [316] Gianpaolo Conte and Patrick Doherty. 2008. Use of Geo-referenced Images with Unmanned Aerial Systems. In Workshop Proceedings of SIMPAR 2008, International Conference on Simulation, Modeling and Programming for Autonomous Robots. Venice(Italy) 2008 November,3-4., pages 444–454. ISBN: 978-88-95872-01-8. [315] Cyrille Berger and Simon Lacroix. 2008. Modlisation de l'environnement par facettes planes pour la Cartographie et la Localisation Simultanes par strovision. In Reconnaissance des Formes et Intelligence Artificielle (RFIA). [314] Cyrille Berger and Simon Lacroix. 2008. Using planar facets for stereovision SLAM. In Proceedings of the IEEE/RSJ International Conference on Intelligent RObots and Systems (IROS), pages 1606–1611. IEEE conference proceedings. ISBN: 978-1-4244-2057-5. DOI: 10.1109/IROS.2008.4650986. In the context of stereovision SLAM, we propose a way to enrich the landmark models. Vision-based SLAM approaches usually rely on interest points associated to a point in the Cartesian space: by adjoining oriented planar patches (if they are present in the environment), we augment the landmark description with an oriented frame. Thanks to this additional information, the robot pose is fully observable with the perception of a single landmark, and the knowledge of the patches orientation helps the matching of landmarks. The paper depicts the chosen landmark model, the way to extract and match them, and presents some SLAM results obtained with such landmarks. [313] Anders Holmberg and Per-Magnus Olsson. 2008. Route Planning for Relay UAV. In Proceedings of the 26th International Congress of the Aeronautical Sciences (ICAS). Optimage Ltd.. ISBN: ISBN 0-9533991-9-2. To expand the operative area for surveillance UAV, we propose the use of a relay UAV. The relay UAV is used as an intermediary node in a communication network: the surveillance UAV transmits data to the relay UAV, which sends it back to a ground station. In this exploratory report, we calculate the route for a relay UAV, to ensure communication at certain time points, given the route of the surveillance UAV. The results presented here are preliminary and may be considered a first iteration of ideas and methods. [312] Joe Steinhauer. 2008. Object Configuration Reconstruction from Descriptions using Relative and Intrinsic Reference Frames. In ECAI 2008, pages 821–822. In series: Frontiers in Artificial Intelligence and Applications #178. IOS Press. ISBN: 978-1-58603-891-5. DOI: 10.3233/978-1-58603-891-5-821. We provide a technique to reconstruct an object configuration that has been described on site by only using intrinsic and relative frames of reference into an absolute frame of reference, as seen from the survey perspective. [311] Per Nyblom and Patrick Doherty. 2008. Towards Automatic Model Generation by Optimization. In Proceedings of the Tenth Scandinavian Conference on Artificial Intelligence (SCAI), pages 114–123. In series: Frontiers in Artificial Intelligence and Applications #173. IOS Press. ISBN: 978-1-58603-867-0, e-978-1-60750-335-4. Link to publication: http://www.booksonline.iospress.nl/Conte... The problem of automatically selecting simulation models for autonomous agents depending on their current intentions and beliefs is considered in this paper. The intended use of the models is for prediction, filtering, planning and other types of reasoning that can be performed with Simulation models. The parameters and model fragments of the resulting model are selected by formulating and solving a hybrid constrained optimization problem that captures the intuition of the preferred model when relevance information about the elements of the world being modelled is taken into consideration. A specialized version of the original optimization problem is developed that makes it possible to solve the continuous subproblem analytically in linear time. A practical model selection problem is discussed where the aim is to select suitable parameters and models for tracking dynamic objects. Experiments with randomly generated problem instances indicate that a hillclimbing search approach might be both efficient and provides reasonably good solutions compared to simulated annealing and hillclimbing with random restarts. [310] Rickard Karlsson, Thomas Schn, David Trnqvist, Gianpolo Conte and Fredrik Gustafsson. 2008. Utilizing Model Structure for Efficient Simultaneous Localization and Mapping for a UAV Application. Technical Report. In series: LiTH-ISY-R #2836. Linkping University Electronic Press. 10 pages. This contribution aims at unifying two recent trends in applied particle filtering (PF). The first trend is the major impact in simultaneous localization and mapping (SLAM) applications, utilizing the FastSLAM algorithm. Thesecond one is the implications of the marginalized particle filter (MPF) or the Rao-Blackwellized particle filter (RBPF) in positioning and tracking applications. Using the standard FastSLAM algorithm, only low-dimensional vehicle modelsare computationally feasible. In this work, an algorithm is introduced which merges FastSLAM and MPF, and the result is an algorithm for SLAM applications, where state vectors of higher dimensions can be used. Results using experimental data from a UAV (helicopter) are presented. The algorithmfuses measurements from on-board inertial sensors (accelerometer and gyro) and vision in order to solve the SLAM problem, i.e., enable navigation over a long period of time. [309] Hkan Warnquist and Mattias Nyberg. 2008. A Heuristic for Near-Optimal Troubleshooting Using AO*. In Proceedings of the International Workshop on the Principles of Diagnosis. When troubleshooting malfunctioning technical equipment, the task is to locate faults and make repairsuntil the equipment functions properly again. The AO* algorithm can be used to find troubleshootingstrategies that are optimal in the sense that the expected cost of repair is minimal. We have adaptedthe AO* algorithm for troubleshooting in the automotive domain with limited time. We propose a newheuristic based on entropy. By using this heuristic, near-optimal strategies can be found within a fixedtime limit. This is shown in empirical studies on a fuel injection system of a truck. In these results, theAO* algorithm using the new heuristic, performs better than other troubleshooting algorithms. [308] Hkan Warnquist, Mattias Nyberg and Petter Sby. 2008. Troubleshooting when Action Costs are Dependent with Application to a Truck Engine. In 10th Scandinavian Conference on Artificial Intelligence, SCAI 2008, pages 68–75. In series: Frontiers in Artificial Intelligence and Applications #173. IOS Press. ISBN: 978-1-58603-867-0, e-978-1-60750-335-4. Link to paper: http://books.google.se/books?id=eju691VM... We propose a troubleshooting algorithm that can troubleshoot systems with dependent action costs. When actions are performed they may change the way the system is decomposed and affect the cost of future actions. We present a way to model this by extending the traditional troubleshooting model with an additional state that describes which parts of the system that are decomposed. The proposed troubleshooting algorithm searches an AND/OR graph with the aim of finding the repair plan that minimizes the expected cost of repair. We present the heuristics needed to speed up the search and make it competitive with other troubleshooting algorithms. Finally, the performance of the algorithm is evaluated on a probabilistic model of a fuel injection system of a truck.We show that the expected cost of repair can be reduced when compared with an algorithm from previous literature. [307] Erik Johan Sandewall. 2008. Extending the concept of publication: Factbases and knowledgebases. Learned Publishing, 21(2):123–131. Association of Learned and Professional Society Publishers. DOI: 10.1087/095315108X288893. The concept of a 'publication' no longer applies only to printed works, information technology has extended its application to several other types of works. This article describes a facility called the Common Knowledge Library that publishes modules of formally structured information representing facts and knowledge of various kinds. Publications of this new type have some characteristics in common with databases, and others in common with software modules, however, they also share some important characteristics with traditional publications. A framework for citation of previous work is important in order to provide an incentive for contributors of such modules. Peer review - the traditional method of quality assurance for scientific articles - must also be applied, although in a modified form, for fact and knowledge modules. The construction of the Common Knowledge Library is a cumulative process, new contributions are obtained by interpreting the contents of existing knowledge sources on the Internet, and the existing contents of the Library are an important resource for that interpretation process. [306] Gianpaolo Conte and Patrick Doherty. 2008. An Integrated UAV Navigation System Based on Aerial Image Matching. In IEEE Aerospace Conference 2008,2008, pages 3142–3151. In series: IEEE Aerospace Conference #??. IEEE. ISBN: 978-1-4244-1487-1, 978-1-4244-1488-8. DOI: 10.1109/AERO.2008.4526556. The aim of this paper is to explore the possibility of using geo-referenced satellite or aerial images to augment an Unmanned Aerial Vehicle (UAV) navigation system in case of GPS failure. A vision based navigation system which combines inertial sensors, visual odometer and registration of a UAV on-board video to a given geo-referenced aerial image has been developed and tested on real flight-test data. The experimental results show that it is possible to extract useful position information from aerial imagery even when the UAV is flying at low altitude. It is shown that such information can be used in an automated way to compensate the drift of the UAV state estimation which occurs when only inertial sensors and visual odometer are used. [305] Gianpaolo Conte, Maria Hempel, Piotr Rudol, David Lundstrm, Simone Duranti, Mariusz Wzorek and Patrick Doherty. 2008. High Accuracy Ground Target Geo-Location Using Autonomous Micro Aerial Vehicle Platforms. In Proceedings of the AIAA Guidance, Navigation, and Control Conference (GNC). AIAA. ISBN: 978-1-56347-945-8. This paper presents a method for high accuracy ground target localization using a Micro Aerial Vehicle (MAV) equipped with a video camera sensor. The proposed method is based on a satellite or aerial image registration technique. The target geo-location is calculated by registering the ground target image taken from an on-board video camera with a geo- referenced satellite image. This method does not require accurate knowledge of the aircraft position and attitude, therefore it is especially suitable for MAV platforms which do not have the capability to carry accurate sensors due to their limited payload weight and power resources. The paper presents results of a ground target geo-location experiment based on an image registration technique. The platform used is a MAV prototype which won the 3rd US-European Micro Aerial Vehicle Competition (MAV07). In the experiment a ground object was localized with an accuracy of 2.3 meters from a ight altitude of 70 meters. [304] Piotr Rudol and Patrick Doherty. 2008. Human Body Detection and Geolocalization for UAV Search and Rescue Missions Using Color and Thermal Imagery. In Proceedings of the IEEE Aerospace Conference, pages 1–8. In series: Aerospace Conference Proceedings #2008. IEEE. ISBN: 978-1-4244-1488-8, 978-1-4244-1487-1. DOI: 10.1109/AERO.2008.4526559. Recent advances in the field of Unmanned Aerial Vehicles (UAVs) make flying robots suitable platforms for carrying sensors and computer systems capable of performing advanced tasks. This paper presents a technique which allows detecting humans at a high frame rate on standard hardware onboard an autonomous UAV in a real-world outdoor environment using thermal and color imagery. Detected human positions are geolocated and a map of points of interest is built. Such a saliency map can, for example, be used to plan medical supply delivery during a disaster relief effort. The technique has been implemented and tested on-board the UAVTech1 autonomous unmanned helicopter platform as a part of a complete autonomous mission. The results of flight- tests are presented and performance and limitations of the technique are discussed. [303] Andrzej Szalas. 2008. Towards Incorporating Background Theories into Quantifier Elimination. Journal of applied non-classical logics, 18(2-3):325–340. ditions Herms-Lavoisier. DOI: 10.3166/jancl.18.325-340. In the paper we present a technique for eliminating quantifiers of arbitrary order, in particular of first-order. Such a uniform treatment of the elimination problem has been problematic up to now, since techniques for eliminating first-order quantifiers do not scale up to higher-order contexts and those for eliminating higher-order quantifiers are usually based on a form of monotonicity w.r.t implication (set inclusion) and are not applicable to the first-order case. We make a shift to arbitrary relations \"ordering\" the underlying universe. This allows us to incorporate background theories into higher-order quantifier elimination methods which, up to now, has not been achieved. The technique we propose subsumes many other results, including the Ackermann's lemma and various forms of fixpoint approaches when the \"ordering\" relations are interpreted as implication and reveals the common principle behind these approaches. [302] Erik Sandewall. 2008. Artificial Intelligence Needs Open-Access Knowledgebase Contents. In Proceedings of the 23rd AAAI Conference on Artificial Intelligence (AAAI), pages 1602–1605. AAAI Press. ISBN: 978-1-57735-368-3, 978-1-57735-367-6. Note: Senior Members track A substantial knowledgebase is an important part of many A.I. applications as well as (arguably) in any system that is claimed to implement broad-range intelligence. Although this has been an accepted view in our field since very long, little progress has been made towards the establishment of large and sharable knowledgebases. Both basic research projects and applications projects have found it necessary to construct special-purpose knowledgebases for their respective needs. This is obviously a problem: it would save work and speed up progress if the construction of a broadly sharable and broadly useful knowledgebase could be a joint undertaking for the field. In this article I wish to discuss the possibilities and the obstacles in this respect. I shall argue that the field of Knowledge Representation needs to adopt a new and very different paradigm in order for progress to be made, so that besides working as usual on logical foundations and on algorithms, we should also devote substantial efforts to the systematic preparation of knowledgebase contents. [301] Patrick Doherty and Andrzej Szalas. 2008. Reasoning with Qualitative Preferences and Cardinalities Using Generalized Circumscription. In Gerhard Brewka, Jérôme Lang, editors, Proceedings of the 11th International Conference on Principles of Knowledge Representation and Reasoning (KR), pages 560–570. AAAI Press. ISBN: 978-1-57735-384-3. The topic of preference modeling has recently attracted the interest of a number of sub-disciplines in artificial intelligence such as the nonmonotonic reasoning and action and change communities. The approach in these communities focuses on qualitative preferences and preference models which provide more natural representations from a~commonsense perspective. In this paper, we show how generalized circumscription can be used as a highly expressive framework for qualitative preference modeling. Generalized circumscription proposed by Lifschitz allows for predicates (and thus formulas) to be minimized relative to arbitrary pre-orders (reflexive and transitive). Although it has received little attention, we show how it may be used to model and reason about elaborate qualitative preference relations. One of the perceived weaknesses with any type of circumscription is the 2nd-order nature of the representation. The paper shows how a large variety of preference theories represented using generalized circumscription can in fact be reduced to logically equivalent first-order theories in a constructive way. Finally, we also show how preference relations represented using general circumscription can be extended with cardinality constraints and when these extensions can also be reduced to logically equivalent first-order theories. [300] Dov M. Gabbay, Renate A. Schmidt and Andrzej Szalas. 2008. Second-Order Quantifier Elimination. Foundations, Computational Aspects and Applications. Book. In series: Studies in Logics #12. College Publications. 308 pages. ISBN: 978-1-904987-56-7, 1-904-98-756-7. link: http://www.amazon.com/Second-Order-Quant... In recent years there has been an increasing use of logical methods and significant new developments have been spawned in several areas of computer science, ranging from artificial intelligence and software engineering to agent-based systems and the semantic web. In the investigation and application of logical methods there is a tension between: * the need for a representational language strong enough to express domain knowledge of a particular application, and the need for a logical formalism general enough to unify several reasoning facilities relevant to the application, on the one hand, and * the need to enable computationally feasible reasoning facilities, on the other hand. Second-order logics are very expressive and allow us to represent domain knowledge with ease, but there is a high price to pay for the expressiveness. Most second-order logics are incomplete and highly undecidable. It is the quantifiers which bind relation symbols that make second-order logics computationally unfriendly. It is therefore desirable to eliminate these second-order quantifiers, when this is mathematically possible; and often it is. If second-order quantifiers are eliminable we want to know under which conditions, we want to understand the principles and we want to develop methods for second-order quantifier elimination. This book provides the first comprehensive, systematic and uniform account of the state-of-the-art of second-order quantifier elimination in classical and non-classical logics. It covers the foundations, it discusses in detail existing second-order quantifier elimination methods, and it presents numerous examples of applications and non-standard uses in different areas. These include: * classical and non-classical logics, * correspondence and duality theory, * knowledge representation and description logics, * commonsense reasoning and approximate reasoning, * relational and deductive databases, and * complexity theory. The book is intended for anyone interested in the theory and application of logics in computer science and artificial intelligence. [299] Erik Sandewall. 2008. The Leordo Computation System. In Yves Bertot, Gérard Huet, Jean-Jacques Lévy, Gordon Plotkin., editors, From Semantics to Computer Science: Essays in Honour of Gilles Kahn, pages 309–336. Cambridge University Press. ISBN: 978-05-21-51825-3, 978-05-11-77052-4. DOI: 10.1017/CBO9780511770524.015. find book at a swedish library/hitta boken i ett svenskt bibliotek: http://libris.kb.se/bib/12013235 läs hela texten: http://ebooks.cambridge.org/ebook.jsf?bi... link: http://www.amazon.com/From-Semantics-Com... Gilles Kahn was one of the most influential figures in the development of computer science and information technology, not only in Europe but throughout the world. This volume of articles by several leading computer scientists serves as a fitting memorial to Kahn's achievements and reflects the broad range of subjects to which he contributed through his scientific research and his work at INRIA, the French National Institute for Research in Computer Science and Control. The editors also reflect upon the future of computing: how it will develop as a subject in itself and how it will affect other disciplines, from biology and medical informatics, to web and networks in general. Its breadth of coverage, topicality, originality and depth of contribution, make this book a stimulating read for all those interested in the future development of information technology. [298] H.Joe Steinhauer. 2008. Object Configuration Reconstruction from Incomplete Binary Object Relation Descriptions. In Dengel, A.; Berns, K.; Breuel, Th.; Bomarius, F.; Roth-Berghofer, Th.R., editors, Proceedings of the 31st German Conference on Advances in Artificial Intelligence (KI), pages 348–355. In series: Lecture Notes in Computer Science #5243. Springer. ISBN: 978-3-540-85844-7. DOI: 10.1007/978-3-540-85845-4_43. We present a process for reconstructing object configurations described by a set of spatial constraints of the form (A northeast B) into a two-dimensional grid. The reconstruction process is cognitively easy for a person to fulfill and guides the user to avoid typical mistakes. For underspecified object configuration descriptions we suggest a strategy to handle coarse object relationships by representing a coarse object in a way that all disjunctive basic relationships that the coarse relationship consists of are represented within one reconstruction. [297] Erik Sandewall. 2008. A Review of the Handbook of Knowledge Representation. Artificial Intelligence, 172(18):1965–1966. Elsevier. DOI: 10.1016/j.artint.2008.10.002. The newly appeared Handbook of Knowledge Representation is an impressive piece of work. Its three editors and its forty-five contributors have produced twenty-five concise, textbook-style chapters that introduce most of the major aspects of the science of knowledge representation. Reading this book is a very positive experience: it demonstrates the breadth, the depth and the coherence that our field has achieved by now. [296] Fredrik Heintz and Patrick Doherty. 2008. DyKnow Federations: Distributing and Merging Information Among UAVs. In Proceedings of the 11th International Conference on Information Fusion (FUSION). IEEE conference proceedings. ISBN: 978-3-8007-3092-6. As unmanned aerial vehicle (UAV) applications become more complex and versatile there is an increasing need to allow multiple UAVs to cooperate to solve problems which are beyond the capability of each individual UAV. To provide more complete and accurate information about the environment we present a DyKnow federation framework for information integration in multi-node networks of UAVs. A federation is created and maintained using a multiagent delegation framework and allows UAVs to share local information as well as process information from other UAVs as if it were local using the DyKnow knowledge processing middleware framework. The work is presented in the context of a multi UAV traffic monitoring scenario. [295] Martin Magnusson and Patrick Doherty. 2008. Temporal Action Logic for Question Answering in an Adventure Game. In Artificial General Intelligence, AGI 2008, pages 236–247. In series: Frontiers in Artificial Intelligence and Applications #15. IOS Press. ISBN: 978-1-58603-833-5. Inhabiting the complex and dynamic environments of modern computer games with autonomous agents capable of intelligent timely behaviour is a significant research challenge. We illustrate this using Our own attempts to build a practical agent architecture on it logicist foundation. In the ANDI-Land adventure game concept players solve puzzles by eliciting information from computer characters through natural language question answering. While numerous challenges immediately presented themselves, they took on a form of concrete and accessible problems to solve, and we present some of our initial solutions. We conclude that games, due to their demand for human-like computer characters with robust and independent operation in large simulated worlds, might serve as excellent test beds for research towards artificial general intelligence. [294] Martin Magnusson, David Landn and Patrick Doherty. 2008. Planning, Executing, and Monitoring Communication in a Logic-Based Multi-Agent System. In ECAI 2008, pages 933–934. In series: Frontiers in Artificial Intelligence and Applications #178. IOS Press. ISBN: 978-1-58603-891-5. DOI: 10.3233/978-1-58603-891-5-933. [293] Martin Magnusson and Patrick Doherty. 2008. Deductive Planning with Inductive Loops. In Proceedings of the 11th International Conference on Principles of Knowledge Representation and Reasoning (KR), pages 528–534. AAAI Press. ISBN: 978-1-57735-384-3. Agents plan to achieve and maintain goals. Maintenance that requires continuous action excludes the representation of plans as finite sequences of actions. If there is no upper bound on the number of actions, a simple list of actions would be infinitely long. Instead, a compact representation requires some form of looping construct. We look at a specific temporally extended maintenance goal, multiple target video surveillance, and formalize it in Temporal Action Logic. The logic's representation of time as the natural numbers suggests using mathematical induction to deductively plan to satisfy temporally extended goals. Such planning makes use of a sound and useful, but incomplete, induction rule that compactly represents the solution as a recursive fixpoint formula. Two heuristic rules overcome the problem of identifying a sufficiently strong induction hypothesis and enable an automated solution to the surveillance problem that satisfies the goal indefinitely. [292] Martin Magnusson and Patrick Doherty. 2008. Logical Agents for Language and Action. In 4th International Artificial Intelligence and Interactive Digital Entertainment Conference AIIDE 2008,2008. AAAI Press. ISBN: 978-1-57735-391-1. [291] Fredrik Heintz, Jonas Kvarnstrm and Patrick Doherty. 2008. Bridging the Sense-Reasoning Gap: DyKnow - A Middleware Component for Knowledge Processing. In Martin Hulse and Manfred Hild, editors, IROS Workshop on Current Software Frameworks in Cognitive Robotics Integrating Different Computational Paradigms. Note: No proceedings, but CD Developing autonomous agents displaying rational and goal-directed behavior in a dynamic physical environment requires the integration of both sensing and reasoning components. Due to the different characteristics of these components there is a gap between sensing and reasoning. We believe that this gap can not be bridged in a single step with a single technique. Instead, it requires a more general approach to integrating components on many different levels of abstraction and organizing them in a structured and principled manner. In this paper we propose knowledge processing middleware as a systematic approach for organizing such processing. Desirable properties of such middleware are presented and motivated. We then go on to argue that a declarative streambased system is appropriate to provide the desired functionality. Finally, DyKnow, a concrete example of stream-based knowledge processing middleware that can be used to bridge the sense-reasoning gap, is presented. Different types of knowledge processes and components of the middleware are described and motivated in the context of a UAV traffic monitoring application. [290] Jonas Kvarnstrm, Fredrik Heintz and Patrick Doherty. 2008. A Temporal Logic-Based Planning and Execution Monitoring System. In Proceedings of the International Conference on Automated Planning and Scheduling (ICAPS). AAAI Press. ISBN: 978-1-57735-386-7, 978-1-57735-387-4. As no plan can cover all possible contingencies, the ability to detect failures during plan execution is crucial to the robustness of any autonomous system operating in a dynamic and uncertain environment. In this paper we present a general planning and execution monitoring system where formulas in an expressive temporal logic specify the desired behavior of a system and its environment. A unified domain description for planning and monitoring provides a solid shared declarative semantics permitting the monitoring of both global and operator-specific conditions. During plan execution, an execution monitor subsystem detects violations of monitor formulas in a timely manner using a progression algorithm on incrementally generated partial logical models. The system has been integrated on a fully deployed autonomous unmanned aircraft system. Extensive empirical testing has been performed using a combination of actual flight tests and hardware-in-the-loop simulations in a number of different mission scenarios. [289] Per-Magnus Olsson and Patrick Doherty. 2008. The Observer Algorithm For Visibility Approximation. In 10th Scandinavian Conference on Artificial Intelligence, SCAI 2008, pages 3–11. In series: Frontiers in Artificial Intelligence and Applications #173. IOS Press. ISBN: 978-1-58603-867-0, e-978-1-60750-335-4. Link to paper: http://books.google.se/books?id=eju691VM... We present a novel algorithm for visibility approximation that is substantially faster than ray casting based algorithms. The algorithm does not require extensive preprocessing or specialized hardware as most other algorithms do. We test this algorithm in several settings: rural, mountainous and urban areas, with different view ranges and grid cell sizes. By changing the size of the grid cells that the algorithm uses, it is possible to tailor the algorithm between speed and accuracy. [288] Rickard Karlsson, Thomas Schn, David Trnqvist, Gianpaolo Conte and Fredrik Gustafsson. 2008. Utilizing Model Structure for Efficient Simultaneous Localization and Mapping for a UAV Application. In Proceedings of the 2008 IEEE Aerospace Conference, pages 1–10. ISBN: 978-1-4244-1487-1, 978-1-4244-1488-8. DOI: 10.1109/AERO.2008.4526442. Related report: http://urn.kb.se/resolve?urn=urn:nbn:se:... This contribution aims at unifying two recent trends in applied particle filtering (PF). The first trend is the major impact in simultaneous localization and mapping (SLAM) applications, utilizing the FastSLAM algorithm. The second one is the implications of the marginalized particle filter (MPF) or the Rao-Blackwellized particle filter (RBPF) in positioning and tracking applications. Using the standard FastSLAM algorithm, only low-dimensional vehicle models are computationally feasible. In this work, an algorithm is introduced which merges FastSLAM and MPF, and the result is an algorithm for SLAM applications, where state vectors of higher dimensions can be used. Results using experimental data from a UAV (helicopter) are presented. The algorithm fuses measurements from on-board inertial sensors (accelerometer and gyro) and vision in order to solve the SLAM problem, i.e., enable navigation over a long period of time. [287] Mattias Krysander, Fredrik Heintz, Jacob Roll and Erik Frisk. 2008. Dynamic Test Selection for Reconfigurable Diagnosis. In Proceedings of the 47th IEEE Conference on Decision and Control, pages 1066–1072. In series: IEEE Conference on Decision and Control. Proceedings #??. IEEE. ISBN: 978-1-4244-3124-3, 978-1-4244-3123-6. DOI: 10.1109/CDC.2008.4738793. Detecting and isolating multiple faults is a computationally intense task which typically consists of computing a set of tests, and then computing the diagnoses based on the test results. This paper proposes a method to reduce the computational burden by only running the tests that are currently needed, and dynamically starting new tests when the need changes. A main contribution is a method to select tests such that the computational burden is reduced while maintaining the isolation performance of the diagnostic system. Key components in the approach are the test selection algorithm, the test initialization procedures, and a knowledge processing framework that supports the functionality needed. The approach is exemplified on a relatively small dynamical system, which still illustrates the complexity and possible computational gain with the proposed approach. [286] Aida Vitoria, Andrzej Szalas and Jan Maluszynski. 2008. Four-valued Extension of Rough Sets. In Proceedings of the 3rd International Conference Rough Sets and Knowledge Technology (RSKT), pages 106–114. In series: Lecture Notes in Computer Science #5009. Springer. ISBN: 978-3-540-79720-3. DOI: 10.1007/978-3-540-79721-0_19. Rough set approximations of Pawlak [15] are sometimes generalized by using similarities between objects rather than elementary sets. In practical applications, both knowledge about properties of objects and knowledge of similarity between objects can be incomplete and inconsistent. The aim of this paper is to define set approximations when all sets, and their approximations, as well as similarity relations are four-valued. A set is four-valued in the sense that its membership function can have one of the four logical values: unknown (u), false (f), inconsistent (i), or true (t). To this end, a new implication operator and set-theoretical operations on four-valued sets, such as set containment, are introduced. Several properties of lower and upper approximations of four-valued sets are also presented. [285] Jan Maluszynski, Aida Vitoria and Andrzej Szalas. 2008. Paraconsistent Logic Programs with Four-valued Rough Sets. In Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), pages 41–51. In series: Lecture Notes in Computer Science #5306. Springer. ISBN: 978-3-540-88423-1, 978-3-540-88425-5. DOI: 10.1007/978-3-540-88425-5_5. This paper presents a language for defining four-valued rough sets and to reason about them. Our framework brings together two major fields: rough sets and paraconsistent logic programming. On the one hand it provides a paraconsistent approach, based on four-valued rough sets, for integrating knowledge from different sources and reasoning in the presence of inconsistencies. On the other hand, it also caters for a specific type of uncertainty that originates from the fact that an agent may perceive different objects of the universe as being indiscernible. This paper extends the ideas presented in [9]. Our language allows the user to define similarity relations and use the approximations induced by them in the definition of other four-valued sets. A positive aspect is that it allows users to tune the level of uncertainty or the source of uncertainty that best suits applications. [284] Rickard Karlsson, Thomas Schn, David Trnqvist, Gianpaolo Conte and Fredrik Gustafsson. 2008. Utilizing Model Structure for Efficient Simultaneous Localization and Mapping for a UAV Application. In Proceedings of Reglermte 2008, pages 313–322. Related report: http://urn.kb.se/resolve?urn=urn:nbn:se:... This contribution aims at unifying two recent trends in applied particle filtering (PF). The first trend is the major impact in simultaneous localization and mapping (SLAM) applications, utilizing the FastSLAM algorithm. Thesecond one is the implications of the marginalized particle filter (MPF) or the Rao-Blackwellized particle filter (RBPF) in positioning and tracking applications. Using the standard FastSLAM algorithm, only low-dimensional vehicle modelsare computationally feasible. In this work, an algorithm is introduced which merges FastSLAM and MPF, and the result is an algorithm for SLAM applications, where state vectors of higher dimensions can be used. Results using experimental data from a UAV (helicopter) are presented. The algorithmfuses measurements from on-board inertial sensors (accelerometer and gyro) and vision in order to solve the SLAM problem, i.e., enable navigation over a long period of time. [283] Fredrik Heintz, Mattias Krysander, Jacob Roll and Erik Frisk. 2008. FlexDx: A Reconfigurable Diagnosis Framework. In Proceedings of the 19th International Workshop on Principles of Diagnosis (DX). Detecting and isolating multiple faults is a computationally intense task which typically consists of computing a set of tests, and then computing the diagnoses based on the test results. This paper describes FlexDx, a reconfigurable diagnosis framework which reduces the computational burden by only running the tests that are currently needed. The method selects tests such that the isolation performance of the diagnostic system is maintained. Special attention is given to the practical issues introduced by a reconfigurable diagnosis framework such as FlexDx. For example, tests are added and removed dynamically, tests are partially performed on historic data, and synchronous and asynchronous processing are combined. To handle these issues FlexDx uses DyKnow, a stream-based knowledge processing middleware framework. The approach is exemplified on a relatively small dynamical system, which still illustrates the computational gain with the proposed approach. [282] Per-Magnus Olsson. 2008. Practical Pathfinding in Dynamic Environments. In Steve Rabin, editor, AI Game Programming Wisdom 4. Charles River. ISBN: 978-1-58450-523-5, 158-450-523-0. find book at a swedish library/hitta boken i ett svenskt bibliotek: http://libris.kb.se/bib/11222031 link: http://www.amazon.com/AI-Game-Programmin... Welcome to the latest volume of AI Game Programming Wisdom! AI Game Programming Wisdom 4 includes a collection of more than 50 new articles featuring cutting-edge techniques, algorithms, and architectures written by industry professionals for use in commercial game development. Organized into 7 sections, this comprehensive volume explores every important aspect of AI programming to help you develop and expand your own personal AI toolbox. You'll find ready-to-use ideas, algorithms, and code in all key AI areas including general wisdom, scripting and dialogue, movement and pathfinding, architecture, tactics and planning, genre specific, and learning and adaptation. New to this volume are articles on recent advances in realistic agent, squad, and vehicle movement, as well as dynamically changing terrain, as exemplified in such popular games as Company of Heroes.You'll also find information on planning as a key game architecture, as well as important new advances in learning algorithms and player modeling. AI Game Programming Wisdom 4 features coverage of multiprocessor architectures, Bayesian networks, planning architectures, conversational AI, reinforcement learning, and player modeling.These valuable and innovative insights and issues offer the possibility of new game AI experiences and will undoubtedly contribute to taking the games of tomorrow to the next level. [281] Piotr Rudol, Mariusz Wzorek, Gianpaolo Conte and Patrick Doherty. 2008. Micro unmanned aerial vehicle visual servoing for cooperative indoor exploration. In Proceedings of the IEEE Aerospace Conference. In series: Aerospace Conference Proceedings #2008. IEEE conference proceedings. ISBN: 978-1-4244-1487-1. DOI: 10.1109/AERO.2008.4526558. Recent advances in the field of micro unmanned aerial vehicles (MAVs) make flying robots of small dimensions suitable platforms for performing advanced indoor missions. In order to achieve autonomous indoor flight a pose estimation technique is necessary. This paper presents a complete system which incorporates a vision-based pose estimation method to allow a MAV to navigate in indoor environments in cooperation with a ground robot. The pose estimation technique uses a lightweight light emitting diode (LED) cube structure as a pattern attached to a MAV. The pattern is observed by a ground robot's camera which provides the flying robot with the estimate of its pose. The system is not confined to a single location and allows for cooperative exploration of unknown environments. It is suitable for performing missions of a search and rescue nature where a MAV extends the range of sensors of the ground robot. The performance of the pose estimation technique and the complete system is presented and experimental flights of a vertical take-off and landing (VTOL) MAV are described. [280] Fredrik Heintz, Jonas Kvarnstrm and Patrick Doherty. 2008. Knowledge Processing Middleware. In S. Carpin, I. Noda, E. Pagello, M. Reggiani and O. von Stryk, editors, Proceedings of the 1st International Conference on Simulation, Modeling, and Programming for Autonomous Robots (SIMPAR), pages 147–158. In series: Lecture Notes in Computer Science #5325. Springer. ISBN: 978-3-540-89075-1, 978-3-540-89076-8. DOI: 10.1007/978-3-540-89076-8_17. fulltext:preprint: http://liu.diva-portal.org/smash/get/div... Developing autonomous agents displaying rational and goal-directed behavior in a dynamic physical environment requires the integration of a great number of separate deliberative and reactive functionalities. This integration must be built on top of a solid foundation of data, information and knowledge having numerous origins, including quantitative sensors and qualitative knowledge databases. Processing is generally required on many levels of abstraction and includes refinement and fusion of noisy sensor data and symbolic reasoning. We propose the use of knowledge processing middleware as a systematic approach for organizing such processing. Desirable properties of such middleware are presented and motivated. We then argue that a declarative stream-based system is appropriate to provide the desired functionality. Different types of knowledge processes and components of the middleware are described and motivated in the context of a UAV traffic monitoring application. Finally DyKnow, a concrete example of stream-based knowledge processing middleware, is briefly described. [279] Oleg Burdakov, Kaj Holmberg and Per-Magnus Olsson. 2008. A Dual Ascent Method for the Hop-constrained Shortest Path with Application to Positioning of Unmanned Aerial Vehicles. Technical Report. In series: Report / Department of Mathematics, Universitetet i Linkping, Tekniska hgskolan #2008:7. Linkping University Electronic Press. 30 pages. We study the problem of positioning unmanned aerial vehicles (UAVs) to maintain an unobstructed flow of communication from a surveying UAV to some base station through the use of multiple relay UAVs. This problem can be modeled as a hopconstrained shortest path problem in a large visibility graph. We propose a dual ascent method for solving this problem, optionally within a branch-and-bound framework. Computational tests show that realistic problems can be solved in a reasonably short time, and that the proposed method is faster than the classical dynamic programming approach. [278] Per Nyblom. 2008. Dynamic Abstraction for Interleaved Task Planning and Execution. Licentiate Thesis. In series: Linkping Studies in Science and Technology. Thesis #1363. Institutionen fr datavetenskap. 94 pages. ISBN: 978-91-7393-905-8. Note: Report code: LiU-Tek-Lic-2008:21. It is often beneficial for an autonomous agent that operates in a complex environment to make use of different types of mathematical models to keep track of unobservable parts of the world or to perform prediction, planning and other types of reasoning. Since a model is always a simplification of something else, there always exists a tradeoff between the model’s accuracy and feasibility when it is used within a certain application due to the limited available computational resources. Currently, this tradeoff is to a large extent balanced by humans for model construction in general and for autonomous agents in particular. This thesis investigates different solutions where such agents are more responsible for balancing the tradeoff for models themselves in the context of interleaved task planning and plan execution. The necessary components for an autonomous agent that performs its abstractions and constructs planning models dynamically during task planning and execution are investigated and a method called DARE is developed that is a template for handling the possible situations that can occur such as the rise of unsuitable abstractions and need for dynamic construction of abstraction levels. Implementations of DARE are presented in two case studies where both a fully and partially observable stochastic domain are used, motivated by research with Unmanned Aircraft Systems. The case studies also demonstrate possible ways to perform dynamic abstraction and problem model construction in practice. [277] Anders Lund, Peter Andersson, J. Eriksson, J. Hallin, T. Johansson, R. Jonsson, H. Lfgren, C. Paulin and A. Tell. 2008. Automatic fitting procedures for EPR spectra of disordered systems: matrix diagonalization and perturbation methods applied to fluorocarbon radicals. Spectrochimica Acta Part A - Molecular and Biomolecular Spectroscopy, 69(5):1294–1300. Elsevier. DOI: 10.1016/j.saa.2007.09.040. Note: Original publication: A. Lund, P. Andersson, J. Eriksson, J. Hallin, T. Johansson, R. Jonsson, H. Löfgren, C. Paulin and A. Tell, Automatic fitting procedures for EPR spectra of disordered systems: matrix diagonalization and perturbation methods applied to fluorocarbon radicals, 2008, Spectrochimica Acta Part A, (69), 5, 1294-1300. http://dx.doi.org/10.1016/j.saa.2007.09.040. Copyright: Elsevier B.V., http://www.elsevier.com/ Two types of automatic fitting procedures for EPR spectra of disordered systems have been developed, one based on matrix diagonalisation of a general spin Hamiltonian, the other on 2nd order perturbation theory. The first program is based on a previous Fortran code complemented with a newly written interface in Java to provide user-friendly in- and output. The second is intended for the special case of free radicals with several relatively weakly interacting nuclei, in which case the general method becomes slow. A least squares’ fitting procedure utilizing analytical or numerical derivatives of the theoretically calculated spectrum with respect to the g-and hyperfine structure (hfs) tensors was used to refine those parameters in both cases. ‘Rigid limit’ ESR spectra from radicals in organic matrices and in polymers, previously studied experimentally at low temperature, were analysed by both methods. Fluoro-carbon anion radicals could be simulated, quite accurately with the exact method, whereas automatic fitting on e.g. the c-C4F8- anion radical is only feasible with the 2nd order approximative treatment. Initial values for the 19F hfs tensors estimated by DFT calculations were quite close to the final. For neutral radicals of the type XCF2CF2• the refinement of the hfs tensors by the exact method worked better than the approximate. The reasons are discussed. The ability of the fitting procedures to recover the correct magnetic parameters of disordered systems was investigated by fittings to synthetic spectra with known hfs tensors. The exact and the approximate methods are concluded to be complementary, one being general, but limited to relatively small systems, the other being a special treatment, suited for S=½ systems with several moderately large hfs. [276] Heike Joe Steinhauer. 2008. A Representation Scheme for Description and Reconstruction of Object Configurations Based on Qualitative Relations. PhD Thesis. In series: Linkping Studies in Science and Technology. Dissertations #1204. Linkping University Electronic Press. 178 pages. ISBN: 978-91-7393-823-5. One reason Qualitative Spatial Reasoning (QSR) is becoming increasingly important to Artificial Intelligence (AI) is the need for a smooth ‘human-like’ communication between autonomous agents and people. The selected, yet general, task motivating the work presented here is the scenario of an object configuration that has to be described by an observer on the ground using only relational object positions. The description provided should enable a second agent to create a map-like picture of the described configuration in order to recognize the configuration on a representation from the survey perspective, for instance on a geographic map or in the landscape itself while observing it from an aerial vehicle. Either agent might be an autonomous system or a person. Therefore, the particular focus of this work lies on the necessity to develop description and reconstruction methods that are cognitively easy to apply for a person.This thesis presents the representation scheme QuaDRO (Qualitative Description and Reconstruction of Object configurations). Its main contributions are a specification and qualitative classification of information available from different local viewpoints into nine qualitative equivalence classes. This classification allows the preservation of information needed for reconstruction nto a global frame of reference. The reconstruction takes place in an underlying qualitative grid with adjustable granularity. A novel approach for representing objects of eight different orientations by two different frames of reference is used. A substantial contribution to alleviate the reconstruction process is that new objects can be inserted anywhere within the reconstruction without the need for backtracking or rereconstructing. In addition, an approach to reconstruct configurations from underspecified descriptions using conceptual neighbourhood-based reasoning and coarse object relations is presented. 2007 [275] Simone Duranti and Gianpaolo Conte. 2007. In-flight Identification of the Augmented Flight Dynamics of the Rmax Unmanned Helicopter. In 17th IFAC Symposium on Automatic Control in Aerospace. International Federation of Automatic Control. DOI: 10.3182/20070625-5-FR-2916.00038. fulltext:postprint: http://liu.diva-portal.org/smash/get/div... The flight dynamics of the Yamaha RMAX unmanned helicopter has been investigated, and mapped into a six degrees of freedom mathematical model. The model has been obtained by a combined black-box system identification technique and a classic model-based parameter identification approach. In particular, the closed-loop behaviour of the built-in attitude control system has been studied, to support the decision whether to keep it as inner stabilization loop or to develop an own stability augmentation system. The flight test method and the test instrumentation are described in detail; some samples of the flight test data are compared to the model outputs as validation, and an overall assessment of the built-in stabilization system is supplied. [274] Barbara Dunin-Keplicz and Andrzej Szalas. 2007. Towards Approximate BGI Systems. In Proceedings of the 5th International Central and Eastern European Conference on Multi-Agent Systems (CEEMAS), pages 277–287. In series: Lecture Notes in Artificial Intelligence #4696. Springer Berlin/Heidelberg. ISBN: 9783540752530. DOI: 10.1007/978-3-540-75254-7_28. This paper focuses on modelling perception and vague concepts in the context of multiagent Bgi (Beliefs, Goals and Intentions) systems. The starting point is the multimodal formalization of such systems. Then we make a shift from Kripke structures to similarity structures, allowing us to model perception and vagueness in an uniform way, “compatible” with the multimodal approach. As a result we introduce and discuss approximate B gi systems, which can also be viewed as a way to implement multimodal specifications of Bgi systems in the context of perception. [273] Thomas Lemaire, Cyrille Berger, Il-Kyun Jung and Simon Lacroix. 2007. Vision-Based SLAM: Stereo and Monocular Approaches. International Journal of Computer Vision, 74(3):343–364. Kluwer Academic Publishers. DOI: 10.1007/s11263-007-0042-3. Building a spatially consistent model is a key functionality to endow a mobile robot with autonomy. Without an initial map or an absolute localization means, it requires to concurrently solve the localization and mapping problems. For this purpose, vision is a powerful sensor, because it provides data from which stable features can be extracted and matched as the robot moves. But it does not directly provide 3D information, which is a difficulty for estimating the geometry of the environment. This article presents two approaches to the SLAM problem using vision: one with stereovision, and one with monocular images. Both approaches rely on a robust interest point matching algorithm that works in very diverse environments. The stereovision based approach is a classic SLAM implementation, whereas the monocular approach introduces a new way to initialize landmarks. Both approaches are analyzed and compared with extensive experimental results, with a rover and a blimp. [272] Karolina Eliasson. 2007. Case-Based Techniques Used for Dialogue Understanding and Planning in a Human-Robot Dialogue System. In Proceedings of the Twentieth International Joint Conference on Artificial Intelligence. [271] Per Nyblom. 2007. Dynamic Planning Problem Generation in a UAV Domain. In 6th IFAC Symposium on Intelligent Autonomous Vehicles (2007) Intelligent Autonomous Vehicles, Volume# 6 | Part# 1, pages 258–263. In series: IFAC Proceedings series #??. Elsevier. ISBN: 978-3-902661-65-4. DOI: 10.3182/20070903-3-FR-2921.00045. One of the most successful methods for planning in large partially observable stochastic domains is depth-limited forward search from the current belief state together with a utility estimation. However, when the environment is continuous and the number of possible actions is practically infinite, then abstractions have to be made before any forward search planning can be performed. The paper presents a method to dynamically generate such planning problem abstractions for a domain that is inspired by our research with unmanned aerial vehicles (UAVs). The planning problems are created by first stating the selection of points to fly to as an optimization problem. When the points have been selected, a set of possible paths between them are then created with a pathplanner and then forward search in the belief state space is applied. The method has been implemented and tested in simulation and the experiments show the importance of modelling both the dynamics of the environment and the limited computational resources of the architecture when searching for suitable parameters in the planning problem formulation procedure. [270] Patrick Doherty, Witold Lukaszewicz and Andrzej Szalas. 2007. Communication between agents with heterogeneous perceptual capabilities. Information Fusion, 8(1):56–69. Elsevier. DOI: 10.1016/j.inffus.2005.05.006. In real world applications robots and software agents often have to be equipped with higher level cognitive functions that enable them to reason, act and perceive in changing, incompletely known and unpredictable environments. One of the major tasks in such circumstances is to fuse information from various data sources. There are many levels of information fusion, ranging from the fusing of low level sensor signals to the fusing of high level, complex knowledge structures. In a dynamically changing environment even a single agent may have varying abilities to perceive its environment which are dependent on particular conditions. The situation becomes even more complex when different agents have different perceptual capabilities and need to communicate with each other. In this paper, we propose a framework that provides agents with the ability to fuse both low and high level approximate knowledge in the context of dynamically changing environments while taking account of heterogeneous and contextually limited perceptual capabilities. To model limitations on an agent's perceptual capabilities we introduce the idea of partial tolerance spaces. We assume that each agent has one or more approximate databases where approximate relations are represented using lower and upper approximations on sets. Approximate relations are generalizations of rough sets. It is shown how sensory and other limitations can be taken into account when constructing and querying approximate databases for each respective agent. Complex relations inherit the approximativeness of primitive relations used in their definitions. Agents then query these databases and receive answers through the filters of their perceptual limitations as represented by (partial) tolerance spaces and approximate queries. The techniques used are all tractable. © 2005 Elsevier B.V. All rights reserved. [269] D.M. Gabbay and Andrzej Szalas. 2007. Second-order quantifier elimination in higher-order contexts with applications to the semantical analysis of conditionals. Studia Logica: An International Journal for Symbolic Logic, 87(1):37–50. Springer. DOI: 10.1007/s11225-007-9075-4. Second-order quantifier elimination in the context of classical logic emerged as a powerful technique in many applications, including the correspondence theory, relational databases, deductive and knowledge databases, knowledge representation, commonsense reasoning and approximate reasoning. In the current paper we first generalize the result of Nonnengart and Szalas [17] by allowing second-order variables to appear within higher-order contexts. Then we focus on a semantical analysis of conditionals, using the introduced technique and Gabbay's semantics provided in [10] and substantially using a third-order accessibility relation. The analysis is done via finding correspondences between axioms involving conditionals and properties of the underlying third-order relation. © 2007 Springer Science+Business Media B.V. [268] Patrick Doherty and Andrzej Szalas. 2007. A correspondence framework between three-valued logics and similarity-based approximate reasoning. Fundamenta Informaticae, 75(1-4):179–193. IOS Press. This paper focuses on approximate reasoning based on the use of similarity spaces. Similarity spaces and the approximated relations induced by them are a generalization of the rough set-based approximations of Pawlak [17, 18]. Similarity spaces are used to define neighborhoods around individuals and these in turn are used to define approximate sets and relations. In any of the approaches, one would like to embed such relations in an appropriate logic which can be used as a reasoning engine for specific applications with specific constraints. We propose a framework which permits a formal study of the relationship between approximate relations, similarity spaces and three-valued logics. Using ideas from correspondence theory for modal logics and constraints on an accessibility relation, we develop an analogous framework for three-valued logics and constraints on similarity relations. In this manner, we can provide a tool which helps in determining the proper three-valued logical reasoning engine to use for different classes of approximate relations generated via specific types of similarity spaces. Additionally, by choosing a three-valued logic first, the framework determines what constraints would be required on a similarity relation and the approximate relations induced by it. Such information would guide the generation of approximate relations for specific applications. [267] David Lawrence, Erik Sandewall and Peter Berkesand. 2007. A Swedish Journal Publication Service. In Hgskolor och samhlle i samverkan (HSS). In 2002, Linköping University Electronic Press began development of a journal article reviewing support system (JARSS) as a tool for Editors of electronic journals. The system-s database contains submitted articles, abstracts and other secondary information, reviews, and e-mail communication for the purpose of submission, reviewing and final acceptance. The interface maintains a log of all events pertaining to the article and the associated status changes. The successive status options of an article (received, under review, conditional accept, etc.) correspond to the editorial workflow. JARRS has been used since its inception to run the Artificial Intelligence Journal (AIJ), an Elsevier publication. In essence a service is offered to take care of the technical aspects of journal publication, allowing editors more time to solicit papers of high quality. [266] Mariusz Wzorek and Patrick Doherty. 2007. A framework for reconfigurable path planning for autonomous unmanned aerial vehicles. Manuscript (preprint). [265] Simone Duranti, Gianpaolo Conte, David Lundstrm, Piotr Rudol, Mariusz Wzorek and Patrick Doherty. 2007. LinkMAV, a prototype rotary wing micro aerial vehicle. In 17th IFAC Symposium on Automatic Control in Aerospace,2007. Elsevier. [264] Patrick Doherty, Barbara Dunin-Keplicz and Andrzej Szalas. 2007. Dynamics of approximate information fusion. In Proceedings of the International Conference on Rough Sets and Emerging Intelligent Systems Paradigms (RSEISP), pages 668–677. In series: Lecture Notes in Artificial Intelligence #4585. Springer Berlin/Heidelberg. ISBN: 978-3-540-73450-5. DOI: 10.1007/978-3-540-73451-2_70. The multi-agent system paradigm has proven to be a useful means of abstraction when considering distributed systems with interacting components. It is often the case that each component may be viewed as an intelligent agent with specific and often limited perceptual capabilities. It is also the case that these agent components may be used as information sources and such sources may be aggregated to provide global information about particular states, situations or activities in the embedding environment. This paper investigates a framework for information fusion based on the use of generalizations of rough set theory and the use of dynamic logic as a basis for aggregating similarity relations among objects where the similarity relations represent individual agents perceptual capabilities or limitations. As an added benefit, it is shown how this idea may also be integrated into description logics. [263] Patrick Doherty and John-Jules Meyer. 2007. Towards a delegation framework for aerial robotic mission scenarios. In Proceedings of the 11th International Workshop on Cooperative Information Agents (CIA), pages 5–26. Springer Berlin/Heidelberg. ISBN: 978-3-540-75118-2. DOI: 10.1007/978-3-540-75119-9_2. The concept of delegation is central to an understanding of the interactions between agents in cooperative agent problem-solving contexts. In fact, the concept of delegation offers a means for studying the formal connections between mixed-initiative problem-solving, adjustable autonomy and cooperative agent goal achievement. In this paper, we present an exploratory study of the delegation concept grounded in the context of a relatively complex multi-platform Unmanned Aerial Vehicle (UAV) catastrophe assistance scenario, where UAVs must cooperatively scan a geographic region for injured persons. We first present the scenario as a case study, showing how it is instantiated with actual UAV platforms and what a real mission implies in terms of pragmatics. We then take a step back and present a formal theory of delegation based on the use of 2APL and KARO. We then return to the scenario and use the new theory of delegation to formally specify many of the communicative interactions related to delegation used in achieving the goal of cooperative UAV scanning. The development of theory and its empirical evaluation is integrated from the start in order to ensure that the gap between this evolving theory of delegation and its actual use remains closely synchronized as the research progresses. The results presented here may be considered a first iteration of the theory and ideas. [262] Patrick Doherty and Piotr Rudol. 2007. A UAV search and rescue scenario with human body detection and geolocalization. In Proceedings of the 20th Australian Joint Conference on Artificial Intelligence (AI). Springer Berlin/Heidelberg. ISBN: 978-3-540-76926-2. The use of Unmanned Aerial Vehicles (UAVs) which can operate autonomously in dynamic and complex operational environments is becoming increasingly more common. The UAVTech Lab, is pursuing a long term research endeavour related to the development of future aviation systems which try and push the envelope in terms of using and integrating high-level deliberative or AI functionality with traditional reactive and control components in autonomous UAV systems. In order to carry on such research, one requires challenging mission scenarios which force such integration and development. In this paper, one of these challenging emergency services mission scenarios is presented. It involves search and rescue for injured civilians by UAVs. In leg I of the mission, UAVs scan designated areas and try to identify injured civilians. In leg II of the mission, an attempt is made to deliver medical and other supplies to identified victims. We show how far we have come in implementing and executing such a challenging mission in realistic urban scenarios. [261] Luis Mejias, Pascual Campoy, Ivn F. Mondragn and Patrick Doherty. 2007. Stereo visual system for autonomous air vehicle navigation. In 6th IFAC Symposium on Intelligent Autonomous Vehicles (2007) Intelligent Autonomous Vehicles, Volume# 6 | Part# 1, pages 203–208. In series: IFAC Proceedings series #??. Elsevier. ISBN: 978-3-902661-65-4. DOI: 10.3182/20070903-3-FR-2921.00037. We present a system to estimate the altitude and motion of an aerial vehicle using a stereo visual system. The system has been initially tested on a ground robot and the novelty lays on its application and robustness validation in an UAV, where vibrations and rapid environmental changes take place. The two main functionalities are height estimation and visual odometry. The system first detects and tracks salient points in the scene. Depth to the plane containing the features is calculated matching features between left and right images then using the disparity principle. Motion is recovered tracking pixels from one frame to the next one finding its visual displacement and resolving camera rotation and translation by a least-square method. We present results from different experimental trials on the two platforms comparing and discussing the results regarding the trajectories calculated by the visual odometry and the onboard helicopter state estimation. [260] Fredrik Heintz, Piotr Rudol and Patrick Doherty. 2007. From Images to Traffic Behavior - A UAV Tracking and Monitoring Application. In Proceedings of the 10th International Conference on Information Fusion (FUSION). IEEE conference proceedings. ISBN: 978-0-662-45804-3, 978-0-662-47830-0. DOI: 10.1109/ICIF.2007.4408103. Link: http://www.ida.liu.se/~frehe/publication... An implemented system for achieving high level situation awareness about traffic situations in an urban area is described. It takes as input sequences of color and thermal images which are used to construct and maintain qualitative object structures and to recognize the traffic behavior of the tracked vehicles in real time. The system is tested both in simulation and on data collected during test flights. To facilitate the signal to symbol transformation and the easy integration of the streams of data from the sensors with the GIS and the chronicle recognition system, DyKnow, a stream-based knowledge processing middleware, is used. It handles the processing of streams, including the temporal aspects of merging and synchronizing streams, and provides suitable abstractions to allow high level reasoning and narrow the sense reasoning gap. [259] Jan Maluszynski, Andrzej Szalas and Aida Vitoria. 2007. A Four-Valued Logic for Rough Set-Like Approximate Reasoning. In James F. Peters, Andrzej Skowron, Ivo Düntsch, Jerzy Grzymala-Busse, Ewa Orlowska and Lech Polkowski, editors, Transactions on Rough Sets VI, pages 176–190. In series: Lecture Notes in Computer Science #4374/2007. Springer. ISBN: 3-540-71198-8, 978-3-540-71198-8. DOI: 10.1007/978-3-540-71200-8_11. find book at a swedish library/hitta boken i ett svenskt bibliotek: http://libris.kb.se/bib/11381912 Annotation The LNCS journal Transactions on Rough Sets is devoted to the entire spectrum of rough sets related issues, from logical and mathematical foundations, through all aspects of rough set theory and its applications, such as data mining, knowledge discovery, and intelligent information processing, to relations between rough sets and other approaches to uncertainty, vagueness, and incompleteness, such as fuzzy sets and theory of evidence. Volume VI of the Transactions on Rough Sets (TRS) commemorates the life and work of Zdzislaw Pawlak (1926-2006). His legacy is rich and varied. Prof. Pawlak's research contributions have had far-reaching implications inasmuch as his works are fundamental in establishing new perspectives for scientific research in a wide spectrum of fields. This volume of the TRS presents papers that reflect the profound influence of a number of research initiatives by Professor Pawlak. In particular, this volume introduces a number of new advances in the foundations and applications of artificial intelligence, engineering, logic, mathematics, and science. These advances have significant implications in a number of research areas such as the foundations of rough sets, approximate reasoning, bioinformatics, computational intelligence, cognitive science, data mining, information systems, intelligent systems, machine intelligence, and security. [258] Fredrik Heintz, Piotr Rudol and Patrick Doherty. 2007. Bridging the Sense-Reasoning Gap Using DyKnow: A Knowledge Processing Middleware Framework. In Joachim Hertzberg, Michael Beetz and Roman Englert, editors, Proceedings of the 30th Annual German Conference on Artificial Intelligence (KI), pages 460–463. In series: Lecture Notes in Computer Science #4667. Springer. ISBN: 978-3-540-74564-8. DOI: 10.1007/978-3-540-74565-5_40. Link: http://www.ida.liu.se/~frehe/publication... To achieve complex missions an autonomous unmanned aerial vehicle (UAV) operating in dynamic environments must have and maintain situational awareness. This can be achieved by continually gathering information from many sources, selecting the relevant information for current tasks, and deriving models about the environment and the UAV itself. It is often the case models suitable for traditional control, are not sufficient for deliberation. The need for more abstract models creates a sense-reasoning gap. This paper presents DyKnow, a knowledge processing middleware framework, and shows how it supports bridging the gap in a concrete UAV traffic monitoring application. In the example, sequences of color and thermal images are used to construct and maintain qualitative object structures. They model the parts of the environment necessary to recognize traffic behavior of tracked vehicles in real-time. The system has been implemented and tested in simulation and on data collected during flight tests. [257] Martin Magnusson and Patrick Doherty. 2007. Deductive Planning with Temporal Constraints. In Commonsense 2007, the 8th International Symposium on Logical Formalizations of Commonsense Reasoning,2007. AAAI Press. ISBN: 978-1-57735-314-0. Link: http://www.ucl.ac.uk/commonsense07/paper... Temporal Action Logic is a well established logical formalism for reasoning about action and change using an explicit time representation that makes it suitable for applications that involve complex temporal reasoning. We take advantage of constraint satisfaction technology to facilitate such reasoning through temporal constraint networks. Extensions are introduced that make generation of action sequences possible, thus paving the road for interesting applications in deductive planning. The extended formalism is encoded as a logic program that is able to realize a least commitment strategy that generates partial order plans in the context of both qualitative and quantitative temporal constraints. [256] Bjrn Hgglund. 2007. A framework for designing constraint stores. Licentiate Thesis. In series: Linkping Studies in Science and Technology. Thesis #1302. Linkpings universitet. 118 pages. ISBN: 978-91-85715-70-1. A constraint solver based on concurrent search and propagation provides a well-defined component model for propagators by enforcing a strict two-level architecture. This makes it straightforward for third parties to invent, implement and deploy new kinds of propagators. The most critical components of such solvers are the constraint stores through which propagators communicate with each other. Introducing stores supporting new kinds of stored constraints can potentially increase the solving power by several orders of magnitude. This thesis presents a theoretical framework for designing stores achieving this without loss of propagator interoperability. [255] Gianpaolo Conte. 2007. Navigation Functionalities for an Autonomous UAV Helicopter. Licentiate Thesis. In series: Linkping Studies in Science and Technology. Thesis #1307. Linkping University Electronic Press. 74 pages. ISBN: 978-91-85715-35-0. This thesis was written during the WITAS UAV Project where one of the goals has been the development of a software/hardware architecture for an unmanned autonomous helicopter, in addition to autonomous functionalities required for complex mission scenarios. The algorithms developed here have been tested on an unmanned helicopter platform developed by Yamaha Motor Company called the RMAX. The character of the thesis is primarily experimental and it should be viewed as developing navigational functionality to support autonomous flight during complex real world mission scenarios. This task is multidisciplinary since it requires competence in aeronautics, computer science and electronics. The focus of the thesis has been on the development of a control method to enable the helicopter to follow 3D paths. Additionally, a helicopter simulation tool has been developed in order to test the control system before flight-tests. The thesis also presents an implementation and experimental evaluation of a sensor fusion technique based on a Kalman filter applied to a vision based autonomous landing problem. Extensive experimental flight-test results are presented. [254] Martin Magnusson. 2007. Deductive Planning and Composite Actions in Temporal Action Logic. Licentiate Thesis. In series: Linkping Studies in Science and Technology. Thesis #1329. Institutionen fr datavetenskap. 85 pages. ISBN: 978-91-85895-93-9. Temporal Action Logic is a well established logical formalism for reasoning about action and change that has long been used as a formal specification language. Its first-order characterization and explicit time representation makes it a suitable target for automated theorem proving and the application of temporal constraint solvers. We introduce a translation from a subset of Temporal Action Logic to constraint logic programs that takes advantage of these characteristics to make the logic applicable, not just as a formal specification language, but in solving practical reasoning problems. Extensions are introduced that enable the generation of action sequences, thus paving the road for interesting applications in deductive planning. The use of qualitative temporal constraints makes it possible to follow a least commitment strategy and construct partially ordered plans. Furthermore, the logical language and logic program translation is extended with the notion of composite actions that can be used to formulate and execute scripted plans with conditional actions, non-deterministic choices, and loops. The resulting planner and reasoner is integrated with a graphical user interface in our autonomous helicopter research system and applied to logistics problems. Solution plans are synthesized together with monitoring constraints that trigger the generation of recovery actions in cases of execution failures. 2006 [253] Ewa Orlowska, Alberto Policriti and Andrzej Szalas. 2006. Algebraic and Relational Deductive Tools. Conference Proceedings. In series: Journal of Applied Non-Classical Logics #??. ditions Herms-Lavoisier. Note: Special Issue [252] Alexander Kleiner, Christian Dornhege, Rainer Kmmerle, Michael Ruhnke, Bastian Steder, Bernhard Nebel, Patrick Doherty, Mariusz Wzorek, Piotr Rudol, Gianpaolo Conte, Simone Duranti and David Lundstrm. 2006. RoboCupRescue - Robot League Team RescueRobots Freiburg (Germany). In RoboCup 2006 (CDROM Proceedings), Team Description Paper, Rescue Robot League. Note: (1st place in the autonomy competition) fulltext:postprint: http://liu.diva-portal.org/smash/get/div... This paper describes the approach of the RescueRobots Freiburg team, which is a team of students from the University of Freiburg that originates from the former CS Freiburg team (RoboCupSoccer) and the ResQ Freiburg team (RoboCupRescue Simulation). Furthermore we introduce linkMAV, a micro aerial vehicle platform. Our approach covers RFID-based SLAM and exploration, autonomous detection of relevant 3D structures, visual odometry, and autonomous victim identification. Furthermore, we introduce a custom made 3D Laser Range Finder (LRF) and a novel mechanism for the active distribution of RFID tags. [251] Erik Sandewall. 2006. Systems - Opening up the process. Nature, ??(??):??–??. Nature Publishing Group. DOI: 10.1038/nature04994. n/a [250] Per Nyblom. 2006. Dynamic Abstraction for Hierarchical Problem Solving and Execution in Stochastic Dynamic Environments. In Loris Penserini, Pavlos Peppas, Anna Perini, editors, STAIRS 2006, pages 263–264. In series: Frontiers in Artificial Intelligence and Applications #142. IOS Press. ISBN: 978-1-58603-645-4, e-978-1-60750-190-9. Link to publication: http://www.booksonline.iospress.nl/Conte... Most of today’s autonomous problem solving agents perform their task with the help of problem domain specifications that keep their abstractions fixed. Those abstractions are often selected by human users. We think that the approach with fixed-abstraction domain specifications is very inflexible because it does not allow the agent to focus its limited computational resources on what may be most relevant at the moment. We would like to build agents that dynamically find suitable abstractions depending on relevance for their current task and situation. This idea of dynamic abstraction has recently been considered an important research problem within the area of hierarchical reinforcement learning [1]. [249] Torsten Merz, Simone Duranti and Gianpaolo Conte. 2006. Autonomous landing of an unmanned helicopter based on vision and inertial sensing. In Marcelo H. Ang and Oussama Khatib, editors, Proceedings of the 9th International Symposium on Experimental Robotics, pages 343–352. In series: Springer Tracts in Advanced Robotics #21. Springer. ISBN: 978-3-540-28816-9. DOI: 10.1007/11552246_33. Link to Ph.D. Thesis: http://urn.kb.se/resolve?urn=urn:nbn:se:... In this paper we propose an autonomous precision landing method for an unmanned helicopter based on an on-board visual navigation system consisting of a single pan-tilting camera, off-the-shelf computer hardware and inertial sensors. Compared to existing methods, the system doesn't depend on additional sensors (in particular not on GPS), offers a wide envelope of starting points for the autonomous approach, and is robust to different weather conditions. Helicopter position and attitude is estimated from images of a specially designed landing pad. We provide results from both simulations and flight tests, showing the performance of the vision system and the overall quality of the landing. © Springer-Verlag Berlin/Heidelberg 2006. [248] Patrik Haslum. 2006. Improving heuristics through relaxed search - An analysis of TP4 and HSP*a in the 2004 planning competition. The journal of artificial intelligence research, 25(??):233–267. AAAI Press. DOI: 10.1613/jair.1885. The h(m) admissible heuristics for (sequential and temporal) regression planning are defined by a parameterized relaxation of the optimal cost function in the regression search space, where the parameter m offers a trade-off between the accuracy and computational cost of the heuristic. Existing methods for computing the h(m) heuristic require time exponential in m, limiting them to small values (m <= 2). The h(m) heuristic can also be viewed as the optimal cost function in a relaxation of the search space: this paper presents relaxed search, a method for computing this function partially by searching in the relaxed space. The relaxed search method, because it compute h(m) only partially, is computationally cheaper and therefore usable for higher values of m. The (complete) h(2) heuristic is combined with partial hm heuristics , for m = 3, ... computed by relaxed search, resulting in a more accurate heuristic. This use of the relaxed search method to improve on the h(2) heuristic is evaluated by comparing two optimal temporal planners: TP4, which does not use it, and HSP*(a), which uses it but is otherwise identical to TP4. The comparison is made on the domains used in the 2004 International Planning Competition, in which both planners participated. Relaxed search is found to be cost effective in some of these domains, but not all. Analysis reveals a characterization of the domains in which relaxed search can be expected to be cost effective, in terms of two measures on the original and relaxed search spaces. In the domains where relaxed search is cost effective, expanding small states is computationally cheaper than expanding large states and small states tend to have small successor states. [247] Klas Nordberg, Patrick Doherty, Per-Erik Forssn, Johan Wiklund and Per Andersson. 2006. A flexible runtime system for image processing in a distributed computational environment for an unmanned aerial vehicle. International Journal of Pattern Recognition and Artificial Intelligence, 20(5):763–780. DOI: 10.1142/S0218001406004867. A runtime system for implementation of image processing operations is presented. It is designed for working in a flexible and distributed environment related to the software architecture of a newly developed UAV system. The software architecture can be characterized at a coarse scale as a layered system, with a deliberative layer at the top, a reactive layer in the middle, and a processing layer at the bottom. At a finer scale each of the three levels is decomposed into sets of modules which communicate using CORBA, allowing system development and deployment on the UAV to be made in a highly flexible way. Image processing takes place in a dedicated module located in the process layer, and is the main focus of the paper. This module has been designed as a runtime system for data flow graphs, allowing various processing operations to be created online and on demand by the higher levels of the system. The runtime system is implemented in Java, which allows development and deployment to be made on a wide range of hardware/software configurations. Optimizations for particular hardware platforms have been made using Java's native interface. [246] Andrzej Szalas and Jerzy Tyszkiewicz. 2006. On the fixpoint theory of equality and its applications. In Proceedings of the 9th International Conference on Relational Methods in Computer Science and 4th International Workshop on Applications of Kleene Algebra (RelMiCS/AKA), pages 388–401. In series: Lecture Notes in Computer Science #4136. Springer. DOI: 10.1007/11828563_26. In the current paper we first show that the fixpoint theory of equality is decidable. The motivation behind considering this theory is that second-order quantifier elimination techniques based on a theorem given in [16], when successful, often result in such formulas. This opens many applications, including automated theorem. proving, static verification of integrity constraints in databases as well as reasoning with weakest sufficient and strongest necessary conditions. [245] Erik Johan Sandewall. 2006. Coordination of actions in an autonomous robotic system. In Oliviero Stock, Marco Schaerf, editors, Reasoning, Action and Interaction in AI Theories and Systems: Essays Dedicated to Luigia Carlucci Aiello, pages 177–191. In series: Lecture Notes in Computer Science #4155. Springer. ISBN: 978-3-5403-7901-0, 978-3-5403-7902-7. DOI: 10.1007/11829263_10. find book at a swedish library/hitta boken i ett svenskt bibliotek: http://libris.kb.se/bib/11430167 link: http://www.amazon.com/Reasoning-Action-I... The present book is a festschrift in honor of Luigia Carlucci Aiello. The 18 articles included are written by former students, friends, and international colleagues, who have cooperated with Luigia Carlucci Aiello, scientifically or in AI boards or committees. The contributions by reputed researchers span a wide range of AI topics and reflect the breadth and depth of Aiello's own work [244] Per Olof Pettersson and Patrick Doherty. 2006. Probabilistic roadmap based path planning for an autonomous unmanned helicopter. Journal of Intelligent & Fuzzy Systems, 17(4):395–405. IOS Press. The emerging area of intelligent unmanned aerial vehicle (UAV) research has shown rapid development in recent years and offers a great number of research challenges for artificial intelligence. For both military and civil applications, there is a desire to develop more sophisticated UAV platforms where the emphasis is placed on development of intelligent capabilities. Imagine a mission scenario where a UAV is supplied with a 3D model of a region containing buildings and road structures and is instructed to fly to an arbitrary number of building structures and collect video streams of each of the building's respective facades. In this article, we describe a fully operational UAV platform which can achieve such missions autonomously. We focus on the path planner integrated with the platform which can generate collision free paths autonomously during such missions. Both probabilistic roadmap-based (PRM) and rapidly exploring random trees-based (RRT) algorithms have been used with the platform. The PRM-based path planner has been tested together with the UAV platform in an urban environment used for UAV experimentation. [243] Fredrik Heintz and Patrick Doherty. 2006. A knowledge processing middleware framework and its relation to the JDL data fusion model. Journal of Intelligent & Fuzzy Systems, 17(4):335–351. IOS Press. Any autonomous system embedded in a dynamic and changing environment must be able to create qualitative knowledge and object structures representing aspects of its environment on the fly from raw or preprocessed sensor data in order to reason qualitatively about the environment and to supply such state information to other nodes in the distributed network in which it is embedded. These structures must be managed and made accessible to deliberative and reactive functionalities whose successful operation is dependent on being situationally aware of the changes in both the robotic agent's embedding and internal environments. DyKnow is a knowledge processing middleware framework which provides a set of functionalities for contextually creating, storing, accessing and processing such structures. The framework is implemented and has been deployed as part of a deliberative/reactive architecture for an autonomous unmanned aerial vehicle. The architecture itself is distributed and uses real-time CORBA as a communications infrastructure. We describe the system and show how it can be used to create more abstract entity and state representations of the world which can then be used for situation awareness by an unmanned aerial vehicle in achieving mission goals. We also show that the framework is a working instantiation of many aspects of the JDL data fusion model. [242] Patrick Doherty, John Mylopoulos and Christopher Welty. 2006. Proceedings of the 10th International Conference on Principles of Knowledge Representation and Reasoning. Conference Proceedings. AAAI Press. ISBN: 978-1-57735-281-5. he National Conference on Artificial Intelligence remains the bellwether for research in artificial intelligence. Leading AI researchers and practitioners as well as scientists and engineers in related fields present theoretical, experimental, and empirical results, covering a broad range of topics that include principles of cognition, perception, and action; the design, application, and evaluation of AI algorithms and systems; architectures and frameworks for classes of AI systems; and analyses of tasks and domains in which intelligent systems perform. The Innovative Applications of Artificial Intelligence conference highlights successful applications of AI technology; explores issues, methods, and lessons learned in the development and deployment of AI applications; and promotes an interchange of ideas between basic and applied AI. This volume presents the proceedings of the latest conferences, held in July, 2006. [241] Martin Magnusson and Patrick Doherty. 2006. Deductive Planning with Temporal Constraints using TAL. In Proceedings of the International Symposium on Practical Cognitive Agents and Robots (PCAR). UWA Press. ISBN: 1-74052-130-7. DOI: 10.1145/1232425.1232444. Temporal Action Logic is a well established logical formalism for reasoning about action and change using an explicit time representation that makes it suitable for applications that involve complex temporal reasoning. We take advantage of constraint satisfaction technology to facilitate such reasoning through temporal constraint networks. Extensions are introduced that make generation of action sequences possible, thus paving the road for interesting applications in deductive planning. The extended formalism is encoded as a logic program that is able to realize a least commitment strategy that generates partial order plans in the context of both qualitative and quantitative temporal constraints. [240] David D. Woods and Erik Hollnagel. 2006. Joint cognitive systems: Patterns in cognitive systems engineering. Book. CRC/Taylor & Francis. 232 pages. ISBN: 978-0-8493-3933-2, 0-8493-3933-2. find book at a swedish library/hitta boken i ett svenskt bibliotek: http://libris.kb.se/hitlist?d=libris&q=9... link: http://www.amazon.com/Joint-Cognitive-Sy... Our fascination with new technologies is based on the assumption that more powerful automation will overcome human limitations and make our systems 'faster, better, cheaper,' resulting in simple, easy tasks for people. But how does new technology and more powerful automation change our work? Research in Cognitive Systems Engineering (CSE) looks at the intersection of people, technology, and work. What it has found is not stories of simplification through more automation, but stories of complexity and adaptation. When work changed through new technology, practitioners had to cope with new complexities and tighter constraints. They adapted their strategies and the artifacts to work around difficulties and accomplish their goals as responsible agents. The surprise was that new powers had transformed work, creating new roles, new decisions, and new vulnerabilities. Ironically, more autonomous machines have created the requirement for more sophisticated forms of coordination across people, and across people and machines, to adapt to new demands and pressures. This book synthesizes these emergent Patterns though stories about coordination and mis-coordination, resilience and brittleness, affordance and clumsiness in a variety of settings, from a hospital intensive care unit, to a nuclear power control room, to a space shuttle control center. The stories reveal how new demands make work difficult, how people at work adapt but get trapped by complexity, and how people at a distance from work oversimplify their perceptions of the complexities, squeezing practitioners. The authors explore how CSE observes at the intersection of people, technology, and work, how CSE abstracts patterns behind the surface details and wide variations, and how CSE discovers promising new directions to help people cope with complexities. The stories of CSE show that one key to well-adapted work is the ability to be prepared to be surprised. Are you ready? [239] Andrzej Szalas. 2006. Second-order Reasoning in Description Logics. Journal of applied non-classical logics, 16(3 - 4):517–530. ditions Herms-Lavoisier. DOI: 10.3166/jancl.16.517-530. Description logics refer to a family of formalisms concentrated around concepts, roles and individuals. They belong to the most frequently used knowledge representation formalisms and provide a logical basis to a variety of well known paradigms. The main reasoning tasks considered in the area of description logics are those reducible to subsumption. On the other hand, any knowledge representation system should be equipped with a more advanced reasoning machinery. Therefore in the current paper we make a step towards integrating description logics with second-order reasoning. One of the important motivations behind introducing second-order formalism follows from the fact that many forms of commonsense and nonmonotonic reasoning used in AI can be modelled within the second-order logic. To achieve our goal we first extend description logics with a possibility to quantify over concepts. Since one of the main criticisms against the use of second-order formalisms is their complexity, we next propose second-order quantifier elimination techniques applicable to a large class of description logic formulas. Finally we show applications of the techniques, in particular in reasoning with circumscribed concepts and approximated terminological formulas. [238] Mariusz Wzorek, David Landn and Patrick Doherty. 2006. GSM Technology as a Communication Media for an Autonomous Unmanned Aerial Vehicle. In Proceedings of the 21st Bristol International UAV Systems Conference (UAVS). University of Bristol, Department of Aerospace engineering. ISBN: 0-9552644-0-5. Note: ISBN: 0-9552644-0-5 [237] Martin Magnusson. 2006. Natural Language Understanding using Temporal Action Logic. In Proceedings of the Workshop on Knowledge and Reasoning for Language Processing (KRAQ). Association for Computational Linguistics. We consider a logicist approach to natural language understanding based on the translation of a quasi-logical form into a temporal logic, explicitly constructed for the representation of action and change, and the subsequent reasoning about this semantic structure in the context of a background knowledge theory using automated theorem proving techniques. The approach is substantiated through a proof-of-concept question answering system implementation that uses a head-driven phrase structure grammar developed in the Linguistic Knowledge Builder to construct minimal recursion semantics structures which are translated into a Temporal Action Logic where both the SNARK automated theorem prover and the Allegro Prolog logic programming environment can be used for reasoning through an interchangeable compilation into first-order logic or logic programs respectively. [236] H.Joe Steinhauer. 2006. Qualitative Reconstruction and Update of an Object Constellation. In Proceedings of the Spatial and Temporal Reasoning Workshop at the 17th European Conference on Artificial Intelligence (ECAI). We provide a technique for describing, reconstructing and updating an object constellation of moving objects. The relations between the constituent objects, in particular axis-parallel and diagonal relations, are verbally expressed using the double cross method for qualitatively characterizing relations between pairs of objects. The same underlying representation is used to reconstruct the constellation from the given description. [235] H.Joe Steinhauer. 2006. Qualitative Communication about Object Scenes. In Proceedings of the 29th Annual German Conference on Artificial Intelligence (KI). [234] Mariusz Wzorek, Gianpaolo Conte, Piotr Rudol, Torsten Merz, Simone Duranti and Patrick Doherty. 2006. From Motion Planning to Control - A Navigation Framework for an Autonomous Unmanned Aerial Vehicle. In Proceedings of the 21st Bristol UAV Systems Conference (UAVS). Link to Ph.D. Thesis: http://urn.kb.se/resolve?urn=urn:nbn:se:... The use of Unmanned Aerial Vehicles (UAVs) which can operate autonomously in dynamic and complex operational environments is becoming increasingly more common. While the application domains in which they are currently used are still predominantly military in nature, in the future we can expect wide spread usage in thecivil and commercial sectors. In order to insert such vehicles into commercial airspace, it is inherently important that these vehicles can generate collision-free motion plans and also be able to modify such plans during theirexecution in order to deal with contingencies which arise during the course of operation. In this paper, wepresent a fully deployed autonomous unmanned aerial vehicle, based on a Yamaha RMAX helicopter, whichis capable of navigation in urban environments. We describe a motion planning framework which integrates two sample-based motion planning techniques, Probabilistic Roadmaps and Rapidly Exploring Random Treestogether with a path following controller that is used during path execution. Integrating deliberative services, suchas planners, seamlessly with control components in autonomous architectures is currently one of the major open problems in robotics research. We show how the integration between the motion planning framework and thecontrol kernel is done in our system.Additionally, we incorporate a dynamic path reconfigurability scheme. It offers a surprisingly efficient method for dynamic replanning of a motion plan based on unforeseen contingencies which may arise during the execution of a plan. Those contingencies can be inserted via ground operator/UAV interaction to dynamically change UAV flight paths on the fly. The system has been verified through simulation and in actual flight. We present empirical results of the performance of the framework and the path following controller. [233] Torsten Merz, Piotr Rudol and Mariusz Wzorek. 2006. Control System Framework for Autonomous Robots Based on Extended State Machines. In Proceedings of the International Conference on Autonomic and Autonomous Systems (ICAS). [232] Mariusz Wzorek and Patrick Doherty. 2006. The WITAS UAV Ground System Interface Demonstration with a Focus on Motion and Task Planning. In Software Demonstrations at the International Conference on Automated Planning Scheduling (ICAPS-SD), pages 36–37. The Autonomous UAV Technologies Laboratory at Linköping University, Sweden, has been developing fully autonomous rotor-based UAV systems in the mini- and micro-UAV class. Our current system design is the result of an evolutionary process based on many years of developing, testing and maintaining sophisticated UAV systems. In particular, we have used the Yamaha RMAX helicopter platform(Fig. 1) and developed a number of micro air vehicles from scratch. [231] Mariusz Wzorek and Patrick Doherty. 2006. Reconfigurable Path Planning for an Autonomous Unmanned Aerial Vehicle. In Derek Long, Stephen F. Smith, Daniel Borrajo, Lee McCluskey, editors, Proceedings of the Sixteenth International Conference on Automated Planning and Scheduling (ICAPS), pages 438–441. AAAI Press. ISBN: 978-1-57735-270-9. In this paper, we present a motion planning framework for a fully deployed autonomous unmanned aerial vehicle which integrates two sample-based motion planning techniques, Probabilistic Roadmaps and Rapidly Exploring Random Trees. Additionally, we incorporate dynamic reconfigurability into the framework by integrating the motion planners with the control kernel of the UAV in a novel manner with little modification to the original algorithms. The framework has been verified through simulation and in actual flight. Empirical results show that these techniques used with such a framework offer a surprisingly efficient method for dynamically reconfiguring a motion plan based on unforeseen contingencies which may arise during the execution of a plan. The framework is generic and can be used for additional platforms. [230] Mariusz Wzorek and Patrick Doherty. 2006. Reconfigurable Path Planning for an Autonomous Unmanned Aerial Vehicle. In ICHIT 2006 - International Conference on Hybrid Information Technology,2006. [229] Bjrn Hgglund and Anders Haraldsson. 2006. The Art and Virtue of Symbolic Constraint Propagation. In CP 2006 Twelfth International Conference on Principles and Practice of Constraint Programming,2006. [228] Ewa Orlowska and Andrzej Szalas. 2006. Quantifier Elimination in Elementary Set Theory. In W. MacCaull, I. Duentsch, M. Winter, editors, Proceedings of the 8th International Conference on Relational Methods in Computer Science (RelMiCS), pages 237–248. In series: Lecture Notes in Computer Science #3929. Springer Berlin/Heidelberg. DOI: 10.1007/11734673_19. In the current paper we provide two methods for quantifier elimination applicable to a large class of formulas of the elementary set theory. The first one adapts the Ackermann method [1] and the second one adapts the fixpoint method of [20]. We show applications of the proposed techniques in the theory of correspondence between modal logics and elementary set theory. The proposed techniques can also be applied in an automated generation of proof rules based on the semantic-based translation of axioms of a given logic into the elementary set theory. [227] Patrick Doherty, Witold Lukaszewicz, Andrzej Skowron and Andrzej Szalas. 2006. Knowledge Representation Techniques.: a rough set approach. Book. In series: Studies in Fuzziness and Soft Computing #202. Springer. 342 pages. ISBN: 978-3-540-33518-4, 3-540-33518-8. DOI: 10.1007/3-540-33519-6. find book at a swedish library/hitta boken i ett svenskt bibliotek: http://libris.kb.se/hitlist?d=libris&q=9... The basis for the material in this book centers around a long term research project with autonomous unmanned aerial vehicle systems. One of the main research topics in the project is knowledge representation and reasoning. The focus of the research has been on the development of tractable combinations of approximate and nonmonotonic reasoning systems. The techniques developed are based on intuitions from rough set theory. Efforts have been made to take theory into practice by instantiating research results in the context of traditional relational database or deductive database systems. This book contains a cohesive, self-contained collection of many of the theoretical and applied research results that have been achieved in this project and for the most part pertain to nonmonotonic and approximate reasoning systems developed for an experimental unmanned aerial vehicle system used in the project. This book should be of interest to the theoretician and applied researcher alike and to autonomous system developers and software agent and intelligent system developers. [226] Patrick Doherty, Martin Magnusson and Andrzej Szalas. 2006. Approximate Databases: A support tool for approximate reasoning. Journal of applied non-classical logics, 16(1-2):87–118. ditions Herms-Lavoisier. DOI: 10.3166/jancl.16.87-117. Note: Special issue on implementation of logics This paper describes an experimental platform for approximate knowledge databases called the Approximate Knowledge Database (AKDB), based on a semantics inspired by rough sets. The implementation is based upon the use of a standard SQL database to store logical facts, augmented with several query interface layers implemented in JAVA through which extensional, intensional and local closed world nonmonotonic queries in the form of crisp or approximate logical formulas can be evaluated tractably. A graphical database design user interface is also provided which simplifies the design of databases, the entering of data and the construction of queries. The theory and semantics for AKDBs is presented in addition to application examples and details concerning the database implementation. [225] Karolina Eliasson. 2006. The Use of Case-Based Reasoning in a Human-Robot Dialog System. Licentiate Thesis. In series: Linkping Studies in Science and Technology. Thesis #1248. Institutionen fr datavetenskap. 130 pages. ISBN: 91-85523-78-X. Note: Report code: LiU{Tek{Lic{2006:29. As long as there have been computers, one goal has been to be able to communicate with them using natural language. It has turned out to be very hard to implement a dialog system that performs as well as a human being in an unrestricted domain, hence most dialog systems today work in small, restricted domains where the permitted dialog is fully controlled by the system.In this thesis we present two dialog systems for communicating with an autonomous agent:The first system, the WITAS RDE, focuses on constructing a simple and failsafe dialog system including a graphical user interface with multimodality features, a dialog manager, a simulator, and development infrastructures that provides the services that are needed for the development, demonstration, and validation of the dialog system. The system has been tested during an actual flight connected to an unmanned aerial vehicle.The second system, CEDERIC, is a successor of the dialog manager in the WITAS RDE. It is equipped with a built-in machine learning algorithm to be able to learn new phrases and dialogs over time using past experiences, hence the dialog is not necessarily fully controlled by the system. It also includes a discourse model to be able to keep track of the dialog history and topics, to resolve references and maintain subdialogs. CEDERIC has been evaluated through simulation tests and user tests with good results. [224] Patrik Haslum. 2006. Admissible Heuristics for Automated Planning. PhD Thesis. In series: Linkping Studies in Science and Technology. Dissertations #1004. Institutionen fr datavetenskap. 164 pages. ISBN: 91-85497-28-2. Link to Licentiate Thesis: http://urn.kb.se/resolve?urn=urn:nbn:se:... The problem of domain-independent automated planning has been a topic of research in Artificial Intelligence since the very beginnings of the field. Due to the desire not to rely on vast quantities of problem specific knowledge, the most widely adopted approach to automated planning is search. The topic of this thesis is the development of methods for achieving effective search control for domain-independent optimal planning through the construction of admissible heuristics. The particular planning problem considered is the so called “classical” AI planning problem, which makes several restricting assumptions. Optimality with respect to two measures of plan cost are considered: in planning with additive cost, the cost of a plan is the sum of the costs of the actions that make up the plan, which are assumed independent, while in planning with time, the cost of a plan is the total execution time – makespan – of the plan. The makespan optimization objective can not, in general, be formulated as a sum of independent action costs and therefore necessitates a problem model slightly different from the classical one. A further small extension to the classical model is made with the introduction of two forms of capacitated resources. Heuristics are developed mainly for regression planning, but based on principles general enough that heuristics for other planning search spaces can be derived on the same basis. The thesis describes a collection of methods, including the hm, additive hm and improved pattern database heuristics, and the relaxed search and boosting techniques for improving heuristics through limited search, and presents two extended experimental analyses of the developed methods, one comparing heuristics for planning with additive cost and the other concerning the relaxed search technique in the context of planning with time, aimed at discovering the characteristics of problem domains that determine the relative effectiveness of the compared methods. Results indicate that some plausible such characteristics have been found, but are not entirely conclusive. [223] Per Olof Pettersson. 2006. Sampling-based Path Planning for an Autonomous Helicopter. Licentiate Thesis. In series: Linkping Studies in Science and Technology. Thesis #1229. Institutionen fr datavetenskap. 141 pages. ISBN: 9185497150. Note: Report code: LiU–Tek–Lic–2006:10. Many of the applications that have been proposed for future small unmanned aerial vehicles (UAVs) are at low altitude in areas with many obstacles. A vital component for successful navigation in such environments is a path planner that can find collision free paths for the UAV.Two popular path planning algorithms are the probabilistic roadmap algorithm (PRM) and the rapidly-exploring random tree algorithm (RRT).Adaptations of these algorithms to an unmanned autonomous helicopter are presented in this thesis, together with a number of extensions for handling constraints at different stages of the planning process.The result of this work is twofold:First, the described planners and extensions have been implemented and integrated into the software architecture of a UAV. A number of flight tests with these algorithms have been performed on a physical helicopter and the results from some of them are presented in this thesis.Second, an empirical study has been conducted, comparing the performance of the different algorithms and extensions in this planning domain. It is shown that with the environment known in advance, the PRM algorithm generally performs better than the RRT algorithm due to its precompiled roadmaps, but that the latter is also usable as long as the environment is not too complex. The study also shows that simple geometric constraints can be added in the runtime phase of the PRM algorithm, without a big impact on performance. It is also shown that postponing the motion constraints to the runtime phase can improve the performance of the planner in some cases. 2005 [222] Peter Andersson. 2005. Hazard: a Framework Towards Connecting Artificial Intelligence and Robotics. In IJCAI Workshop on Reasoning, Representation and Learning in Computer Games. [221] Ewa Madalinska-Bugaj and Witold Lukaszewicz. 2005. Belief revision revisited. In Advances in Artificial Intelligence: Proceedings of the 4th Mexican International Conference on Artificial Intelligence (MICAI), pages 31–40. In series: Lecture Notes in Computer Science #3789. Springer. DOI: 10.1007/11579427_4. In this paper, we propose a new belief revision operator, together with a method of its calculation. Our formalization differs from most of the traditional approaches in two respects. Firstly, we formally distinguish between defeasible observations and indefeasible knowledge about the considered world. In particular, our operator is differently specified depending on whether an input formula is an observation or a piece of knowledge. Secondly, we assume that a new observation, but not a new piece of knowledge, describes exactly what a reasoning agent knows at the moment about the aspect of the world the observation concerns. [220] Patrick Doherty, Andrzej Szalas and Witold Lukaszewicz. 2005. Similarity, approximations and vagueness. In Dominik Slezak, Guoyin Wang, Marcin S. Szczuka, Ivo Düntsch, Yiyu Yao, editors, Proceedings of the 10th International Conference on Rough Sets, Fuzzy Sets, Data Mining, and Granular Computing (RSFDGrC), pages 541–550. In series: Lecture Notes in Artificial Intelligence #3641. Springer. ISBN: 3-540-28653-5. DOI: 10.1007/11548669_56. The relation of similarity is essential in understanding and developing frameworks for reasoning with vague and approximate concepts. There is a wide spectrum of choice as to what properties we associate with similarity and such choices determine the nature of vague and approximate concepts defined in terms of these relations. Additionally, robotic systems naturally have to deal with vague and approximate concepts due to the limitations in reasoning and sensor capabilities. Halpern [1] introduces the use of subjective and objective states in a modal logic formalizing vagueness and distinctions in transitivity when an agent reasons in the context of sensory and other limitations. He also relates these ideas to a solution to the Sorities and other paradoxes. In this paper, we generalize and apply the idea of similarity and tolerance spaces [2,3,4,5], a means of constructing approximate and vague concepts from such spaces and an explicit way to distinguish between an agent’s objective and subjective states. We also show how some of the intuitions from Halpern can be used with similarity spaces to formalize the above-mentioned Sorities and other paradoxes. [219] Fredrik Heintz and Patrick Doherty. 2005. A knowledge processing middleware framework and its relation to the JDL data fusion model. In The 8th International Conference on Information Fusion,2005. [218] Anders Arpteg. 2005. Intelligent semi-structured information extraction: a user-driven approach to information extraction. PhD Thesis. In series: Linkping Studies in Science and Technology. Dissertations #946. Linkping University Electronic Press. 139 pages. ISBN: 91-85297-98-4. Note: This work has been supported by University of Kalmar and the Knowledge Foundation. The number of domains and tasks where information extraction tools can be used needs to be increased. One way to reach this goal is to design user-driven information extraction systems where non-expert users are able to adapt them to new domains and tasks. It is difficult to design general extraction systems that do not require expert skills or a large amount of work from the user. Therefore, it is difficult to increase the number of domains and tasks. A possible alternative is to design user-driven systems, which solve that problem by letting a large number of non-expert users adapt the systems themselves. To accomplish this goal, the systems need to become more intelligent and able to learn to extract with as little given information as possible.The type of information extraction system that is in focus for this thesis is semi-structured information extraction. The term semi-structured refers to documents that not only contain natural language text but also additional structural information. The typical application is information extraction from World Wide Web hypertext documents. By making effective use of not only the link structure but also the structural information within each such document, user-driven extraction systems with high performance can be built.There are two different approaches presented in this thesis to solve the user-driven extraction problem. The first takes a machine learning approach and tries to solve the problem using a modified $Q(\lambda)$ reinforcement learning algorithm. A problem with the first approach was that it was difficult to handle extraction from the hidden Web. Since the hidden Web is about 500 times larger than the visible Web, it would be very useful to be able to extract information from that part of the Web as well. The second approach is called the hidden observation approach and tries to also solve the problem of extracting from the hidden Web. The goal is to have a user-driven information extraction system that is also able to handle the hidden Web. The second approach uses a large part of the system developed for the first approach, but the additional information that is silently obtained from the user presents other problems and possibilities.An agent-oriented system was designed to evaluate the approaches presented in this thesis. A set of experiments was conducted and the results indicate that a user-driven information extraction system is possible and no longer just a concept. However, additional work and research is necessary before a fully-fledged user-driven system can be designed. [217] Kevin McGee. 2005. Enactive Cognitive Science: Part 1, Background and Research Themes. Constructivist foundations, 1(1):19–34. Link: http://www.univie.ac.at/constructivism/j... Enactive cognitivescience is an approach to the study of mind thatseeks to explain how the structures and mechanisms of autonomouscognitive systems can arise and participate in the generation andmaintenance of viable perceiver-dependent worlds -- rather thanmoreconventional cognitivist efforts, such as the attempt to explaincognition in terms of the \"recovery\" of (pre-given, timeless)featuresof The (objectively-existing and accessible) World.As such, enactive cognitive science is resonant with radicalconstructivism. And as with other scientific efforts conductedwithina constructivist orientation, it is broadly \"conventional\" in itsscientific methodology. That is, there is a strong emphasis ontestable hypotheses, empirical observation, supportable mechanismsandmodels, rigorous experimental methods, acceptable criteria ofvalidation, and the like. Nonetheless, this approach to cognitivescience does also raise a number of specific questions about thescopeof amenable phenomena (e.g. meaning, consciousness, etc.) -- anditalso raises questions of whether such a perspective requires anexpansion of what is typically considered within the purview ofscientific method (e.g. the role of the observer/scientist).This paper is a brief introduction to enactive cognitive science: adescription of some of the main research concerns; some examples ofhow such concerns have been realized in actual research; some ofitsresearch methods and proposed explanatory mechanisms and models;someof the potential as both a theoretical and applied science; andseveral of the major open research questions. [216] Michali Grabowski and Andrzej Szalas. 2005. A Technique for Learning Similarities on Complex Structures with Applications to Extracting Ontologies. In Proceedings of the 3rd Atlantic Web Intelligence Conference (AWIC), pages 991–995. In series: Lecture Notes in Computer Science #3528. Springer. DOI: 10.1007/11495772_29. A general similarity-based algorithm for extracting ontologies from data has been provided in [1]. The algorithm works over arbitrary approximation spaces, modeling notions of similarity and mereological part-of relations (see, e.g., [2, 3, 4, 5]). In the current paper we propose a novel technique of machine learning similarity on tuples on the basis of similarities on attribute domains. The technique reflects intuitions behind tolerance spaces of [6] and similarity spaces of [7]. We illustrate the use of the technique in extracting ontologies from data. [215] Erik Johan Sandewall. 2005. Leonardo, an Approach towards the Consolidation of Computer Software System. Note: Research Article, CAISOR Archival Website, Number 2005-016 [214] Erik Johan Sandewall. 2005. Actions as a Basic Software Concept in the Leonardo Computation System. In IJCAI 2005 Workshop on Nonmonotonic Reasoning, Action and Change,2005. [213] Erik Johan Sandewall. 2005. Integration of Live Video in a System for Natural Language Dialog with a Robot. In Proceedings of the 9th workshop on the semantics and pragmatics of dialogue (SemDial). [212] Mariusz Wzorek and Patrick Doherty. 2005. Reconfigurable path planning for an autonomous unmanned aerial vehicle. In National Swedish Workshop on Autonomous Systems, SWAR 05,2005. [211] Mariusz Wzorek and Patrick Doherty. 2005. Preliminary report: Reconfigurable path planning for an autonomous unmanned aerial vehicle. In Proceedings of the 24th Annual Workshop of the UK Planning and Scheduling Special Interest Group (PlanSIG). [210] Patrick Doherty. 2005. Knowledge representation and unmanned aerial vehicles. In Proceedings of the IEEE/WIC/ACM International Conference on Intelligent Agent Technology (IAT), pages 9–16. IEEE Computer Society. ISBN: 0-7695-2416-8. DOI: 10.1109/IAT.2005.93. Knowledge representation technologies play a fundamental role in any autonomous system that includes deliberative capability and that internalizes models of its internal and external environments. Integrating both high- and low-end autonomous functionality seamlessly in autonomous architectures is currently one of the major open problems in robotics research. UAVs offer especially difficult challenges in comparison with ground robotic systems due to the often tight time constraints and safety considerations that must be taken into account. This article provides an overview of some of the knowledge representation technologies and deliberative capabilities developed for a fully deployed autonomous unmanned aerial vehicle system to meet some of these challenges. [209] Bourhane Kadmiry. 2005. Fuzzy gain scheduled visual servoing for an unmanned helicopter. PhD Thesis. In series: Linkping Studies in Science and Technology. Dissertations #938. Linkpings universitet. 148 pages. ISBN: 91-85297-76-3. The overall objective of the Wallenberg Laboratory for Information Technology and Autonomous Systems (WITAS) at Linkoping University is the development of an intelligent command and control system, containing active-vision sensors, which supports the operation of an unmanned air vehicle (UAV). One of the UA V platforms of choice is the R5O unmanned helicopter, by Yamaha.The present version of the UAV platform is augmented with a camera system. This is enough for performing missions like site mapping, terrain exploration, in which the helicopter motion can be rather slow. But in tracking missions, and obstacle avoidance scenarios, involving high-speed helicopter motion, robust performance for the visual-servoing scheme is desired. Robustness in this case is twofold: 1) w.r.t time delays introduced by the image processing; and 2) w.r.t disturbances, parameter uncertainties and unmodeled dynamics which reflect on the feature position in the image, and the camera pose.With this goal in mind, we propose to explore the possibilities for the design of fuzzy controllers, achieving stability, robust and minimal-cost performance w.r.t time delays and unstructured uncertainties for image feature tracking, and test a control solution in both simulation and on real camera platforms. Common to both are model-based design by the use of nonlinear control approaches. The performance of these controllers is tested in simulation using the nonlinear geometric model of a pin-hole camera. Then we implement and test the reSUlting controller on the camera platform mounted on the UAV. [208] Patrik Haslum, Blai Bonet and Hector Geffner. 2005. New Admissible Heuristics for Domain-Independent Planning. In Proceedings of the 20th national Conference on Artificial Intelligence (AAAI). AAAI Press. ISBN: 1-57735-236-X. Admissible heuristics are critical for effective domain-independent planning when optimal solutions must be guaranteed. Two useful heuristics are the hm heuristics, which generalize the reachability heuristic underlying the planning graph, and pattern database heuristics. These heuristics, however, have serious limitations: reachability heuristics capture only the cost of critical paths in a relaxed problem, ignoring the cost of other relevant paths, while PDB heuristics, additive or not, cannot accommodate too many variables in patterns, and methods for automatically selecting patterns that produce good estimates are not known.We introduce two refinements of these heuristics: First, the additive hm heuristic which yields an admissible sum of hm heuristics using a partitioning of the set of actions. Second, the constrained PDB heuristic which uses constraints from the original problem to strengthen the lower bounds obtained from abstractions.The new heuristics depend on the way the actions or problem variables are partitioned. We advance methods for automatically deriving additive hm and PDB heuristics from STRIPS encodings. Evaluation shows improvement over existing heuristics in several domains, although, not surprisingly, no heuristic dominates all the others over all domains. [207] Fredrik Heintz and Patrick Doherty. 2005. A Knowledge processing Middleware Framework and its Relation to the JDL Data Fusion model. In SWAR 05,2005, pages 50–51. [206] Fredrik Heintz and Patrick Doherty. 2005. A Knowledge processing Middleware Framework and its Relation to the JDL Data Fusion model. In 3rd joint SAIS-SSL event on Artificial Intelligence an Learning Systems,2005. Mlardalens University. [205] Peter Andersson. 2005. Hazard: A Framework Towards Connecting Artificial Intelligence and Robotics. In Proceedings of the 1st International Workshop on Multi-Agent Robotic Systems (MARS). INSTICC PRESS. [204] Per Nyblom. 2005. Handling Uncertainty by Interleaving Cost-Aware Classical Planning with Execution. In 3rd joint SAIS-SSL event on Artificial Intelligence and Learning Systems,2005. [203] Martin Magnusson, Patrick Doherty and Andrzej Szalas. 2005. An Experimental Platform for Approximate Databases. In 3rd joint SAIS-SSL event on Artificial Intelligence and Learning Systems,2005. [202] Per Olof Pettersson and Patrick Doherty. 2005. Probabilistic Roadmap Based Path Planning for an Autonomous Unmanned Helicopter. In Peter Funk, Thorsteinn Rögnvaldsson and Ning Xiong, editors, Proceedings of the 3rd joint SAIS-SSLS event on Artificial Intelligence and Learning Systems (SAIS-SSLS). Mlardalen University. The emerging area of intelligent unmanned aerialvehicle (UAV) research has shown rapid development in recentyears and offers a great number of research challenges for artificialintelligence. For both military and civil applications, thereis a desire to develop more sophisticated UAV platforms wherethe emphasis is placed on development of intelligent capabilities.Imagine a mission scenario where a UAV is supplied with a 3Dmodel of a region containing buildings and road structures andis instructed to fly to an arbitrary number of building structuresand collect video streams of each of the building’s respectivefacades. In this article, we describe a fully operational UAVplatform which can achieve such missions autonomously. Wefocus on the path planner integrated with the platform which cangenerate collision free paths autonomously during such missions.It is based on the use of probabilistic roadmaps. The path plannerhas been tested together with the UAV platform in an urbanenvironment used for UAV experimentation. [201] Karolina Eliasson. 2005. Towards a Robotic Dialogue System with Learning and Planning Capabilities. In Ingrid Zukerman, Jan Alexandersson , Arne Jönsson, editors, Proceedings of the IJCAI Workshop on Knowledge and Reasoning in Practical Dialogue Systems (KRPDS), pages 1–7. We present a robotic dialogue system built on casebased reasoning. The system is capable of solving references and manage sub-dialogues in a dialogue with an operator in natural language. The approach to handle dialogue acts and physical acts in a unison manner together with the use of plans and subplans makes the system very flexible. This flexibility is used for learning purposes where the operator teaches the system a new word and the new knowledge can directly be integrated and used in the old plans. The learning from explanation capability makes the system adaptable to the operator's use of language and the domain it is currently operating in. The implementation of a case-based planner suggested in the paper will further increase the learning and adaptation degree. [200] Karolina Eliasson. 2005. Integrating a Discourse Model with a Learning Case-Based Reasoning System. In Proceedings of the 9th workshop on the semantics and pragmatics of dialogue (SemDial). We present a discourse model integrated with a case-based reasoning dialogue system which learns from experience. The discourse model is capable of solving references, manage subdialogues and respect the current topic in a dialogue in natural language. The framework is flexible enough not to disturb the learning functions, but allows dynamic changes to a large extent. The system is tested in a traffic surveillance domain together with a simulated UAV and is found to be robust and reliable. [199] Karolina Eliasson. 2005. An Integrated Discourse Model for a Case-Based Reasoning Dialogue System. In 3rd joint SAIS-SSL event on Artificial Intelligence and Learning Systems,2005. [198] Jonas Kvarnstrm. 2005. TALplanner and other extensions to Temporal Action Logic. PhD Thesis. In series: Linkping Studies in Science and Technology. Dissertations #937. Linkpings universitet. 302 pages. ISBN: 91-85297-75-5. Though the exact definition of the boundary between intelligent and non-intelligent artifacts has been a subject of much debate, one aspect of intelligence that many would deem essential is deliberation: Rather than reacting \"instinctively\" to its environment, an intelligent system should also be capable of reasoning about it, reasoning about the effects of actions performed by itself and others, and creating and executing plans, that is, determining which actions to perform in order to achieve certain goals. True deliberation is a complex topic, requiring support from several different sub-fields of artificial intelligence. The work presented in this thesis spans two of these partially overlapping fields, beginning with reasoning about action and change and eventually moving over towards planning.The qualification problem relates to the difficulties inherent in providing, for each action available to an agent, an exhaustive list of all qualifications to the action, that is, all the conditions that may prevent the action from being executed in the intended manner. The first contribution of this thesis is a framework for modeling qualifications in Temporal Action Logic (TAL).As research on reasoning about action and change proceeds, increasingly complex and interconnected domains are modeled in increasingly greater detail. Unless the resulting models are structured consistently and coherently, they will be prohibitively difficult to maintain. The second contribution is a framework for structuring TAL domains using object-oriented concepts.Finally, the second half of the thesis is dedicated to the task of planning. TLplan pioneered the idea of using domain-specific control knowledge in a temporal logic to constrain the search space of a forward-chaining planner. We develop a new planner called TALplanner, based on the same idea but with fundamental differences in the way the planner verifies that a plan satisfies control formulas. T ALplanner generates concurrent plans and can take resource constraints into account. The planner also applies several new automated domain analysis techniques to control formulas, further increasing performance by orders of magnitude for many problem domains. [197] H.Joe Steinhauer. 2005. Towards a Qualitative Model for Natural Language Communication about Vehicle Traffic. In IJCAI 2005 Workshop on Spatial and Temporal Reasoning,2005. [196] H.Joe Steinhauer. 2005. A Qualitative Model for Natural Language Communication about Vehicle Traffic. In Proceedings of the AAAI Spring Symposium on Reasoning with Mental and External Diagrams - Computational Modeling and Spatial Assistance, pages 52–57. AAAI Press. ISBN: 978-1-57735-232-7. In this paper we describe a qualitative approach for natural language communication about vehicle traffic. It is an intuitive and simple model that can be used as the basis for defining more detailed position descriptions and transitions. It can also function as a framework for relating different aggregation levels. We apply a diagrammatic abstraction of traffic that mirrors the different possible interpretations of it and with this the different mental abstractions that humans might make. The abstractions are kept in parallel and according to the communicative context it will be switched to the corresponding interpretation. 2004 [195] Fredrik Heintz and Patrick Doherty. 2004. DyKnow: A Framework for Processing Dynamic Knowledge and Object Structures in Autonomous Systems. In Proceedings of the Second Joint SAIS/SSLS Workshop. [194] Patrik Haslum. 2004. Patterns in Reactive Programs. In Patrick Doherty, Gerhard Lakemeyer, Angel P. de Pobil, editors, Proceedings of the 4th International Cognitive Robotics Workshop (COGROB), pages 25–29. In this paper, I explore the idea that there are “patterns”,analogous to software design patterns, in the kind of task proceduresthat frequently form the reactive component of architectures for intelligentautonomous systems. The investigation is carried out mainlywithin the context of the WITAS UAV project. [193] Patrick Doherty, Steven Kertes, Martin Magnusson and Andrzej Szalas. 2004. Towards a logical analysis of biochemical pathways. In José Júlio Alferes and João Alexandre Leite, editors, Proceedings of the 9th European Conference on Logics in Artificial Intelligence (JELIA), pages 667–679. In series: Lecture Notes in Computer Science #3229. Springer. ISBN: 978-3-540-23242-1. DOI: 10.1007/978-3-540-30227-8_55. Biochemical pathways or networks are generic representations used to model many different types of complex functional and physical interactions in biological systems. Models based on experimental results are often incomplete, e.g., reactions may be missing and only some products are observed. In such cases, one would like to reason about incomplete network representations and propose candidate hypotheses, which when represented as additional reactions, substrates, products, would complete the network and provide causal explanations for the existing observations. In this paper, we provide a logical model of biochemical pathways and show how abductive hypothesis generation may be used to provide additional information about incomplete pathways. Hypothesis generation is achieved using weakest and strongest necessary conditions which represent these incomplete biochemical pathways and explain observations about the functional and physical interactions being modeled. The techniques are demonstrated using metabolism and molecular synthesis examples. [192] Fredrik Heintz and Patrick Doherty. 2004. DyKnow: An approach to middleware for knowledge processing. Journal of Intelligent & Fuzzy Systems, 15(1):3–13. IOS Press. Any autonomous system embedded in a dynamic and changing environment must be able to create qualitative knowledge and object structures representing aspects of its environment on the fly from raw or preprocessed sensor data in order to reason qualitatively about the environment. These structures must be managed and made accessible to deliberative and reactive functionalities which are dependent on being situationally aware of the changes in both the robotic agent's embedding and internal environment. DyKnow is a software framework which provides a set of functionalities for contextually accessing, storing, creating and processing such structures. The system is implemented and has been deployed in a deliberative/reactive architecture for an autonomous unmanned aerial vehicle. The architecture itself is distributed and uses real-time CORBA as a communications infrastructure. We describe the system and show how it can be used in execution monitoring and chronicle recognition scenarios for UAV applications. [191] Joakim Gustafsson and Jonas Kvarnstrm. 2004. Elaboration tolerance through object-orientation. Artificial Intelligence, 153(1-2):239–285. Elsevier. DOI: 10.1016/j.artint.2003.08.004. Although many formalisms for reasoning about action and change have been proposed in the literature, any concrete examples provided in such articles have primarily consisted of tiny domains that highlight some particular aspect or problem. However, since some of the classical problems are now completely or partially solved and since powerful tools are becoming available, it is now necessary to start modeling more complex domains. This article presents a methodology for handling such domains in a systematic manner using an object-oriented framework and provides several examples of the elaboration tolerance exhibited by the resulting models. (C) 2003 Elsevier B.V. All rights reserved. [190] Bourhane Kadmiry and D. Driankov. 2004. A fuzzy gain-scheduler for the attitude control of an unmanned helicopter. IEEE transactions on fuzzy systems, 12(4):502–515. IEEE Computer Society. DOI: 10.1109/TFUZZ.2004.832539. In this paper, we address the design of an attitude controller that achieves stable, and robust aggressive maneuverability for an unmanned helicopter. The controller proposed is in the form of a fuzzy gain-scheduler, and is used for stable and robust altitude, roll, pitch, and yaw control. The controller is obtained from a realistic nonlinear multiple-input-multiple-output model of a real unmanned helicopter platform, the APID-MK3. The results of this work are illustrated by extensive simulation, showing that the objective of aggressive, and robust maneuverability has been achieved. © 2004 IEEE. [189] Bourhane Kadmiry and P Bergsten. 2004. Robust Fuzzy Gain Scheduled visual-servoing with Sampling Time Uncertainties. In IEEE International Symposium on Intelligent Control ISIC,2004. Abstract-This paper addresses the robust fuzzy control problem for discrete-time nonlinear systems in the presence of sampling time uncertainties in a visual-servoing control scheme. The Takagi-Sugeno (T-S) fuzzy model is adopted for the nonlinear geometric model of a pin-hole camera, which presents second-order nonlinearities. The case of the discrete T-S fuzzy system with sampling-time uncertainty is considered and a multi-objective robust fuzzy controller design is proposed for the uncertain fuzzy system. The sufficient conditions are formulated in the form of linear matrix inequalities (LMI). The effectiveness of the proposed controller design methodology is demonstrated through numerical simulation, then tested on a EVI-D31 SONY camera. [188] Bourhane Kadmiry and Dimiter Driankov. 2004. A Fuzzy Flight Controller Combining Linguistic and Model-based Fuzzy Control. Fuzzy sets and systems (Print), 146(3):313–347. Elsevier. DOI: 10.1016/j.fss.2003.07.002. In this paper we address the design of a fuzzy flight controller that achieves stable and robust -aggressive- manoeuvrability for an unmanned helicopter. The fuzzy flight controller proposed consists of a combination of a fuzzy gain scheduler and linguistic (Mamdani-type) controller. The fuzzy gain scheduler is used for stable and robust altitude, roll, pitch, and yaw control. The linguistic controller is used to compute the inputs to the fuzzy gain scheduler, i.e., desired values for roll, pitch, and yaw at given desired altitude and horizontal velocities. The flight controller is obtained and tested in simulation using a realistic nonlinear MIMO model of a real unmanned helicopter platform, the APID-MK [187] Bourhane Kadmiry and Dimiter Driankov. 2004. Takagi-Sugeno Fuzzy Gain Scheduling with Sampling-Time Uncertainties. In IEEE International Conference on Fuzzy Systems Fuzz-IEEE 2004,2004. This paper addresses the robust fuzzy control problem for discrete-time nonlinear systems in the presence of sampling time uncertainties. The case of the discrete T-S fuzzy system with sampling-time uncertainty is considered and a robust controller design method is proposed. The sufficient conditions and the design procedure are formulated in the form of linear matrix inequalities (LMI). The effectiveness of the proposed controller design methodology is demonstrated of a visual-servoing control problem [186] Ubbo Visser and Patrick Doherty. 2004. Issues in Designing Physical Agents for Dynamic Real-Time Environments: World Modeling, Planning, Learning, and Communicating. The AI Magazine, 25(2):137–138. AAAI Press. This article discusses a workshop held in conjunction with the Eighteenth International Joint Conference on Artificial Intelligence (IJCAI-03), held in Acapulco, Mexico, on 11 August 2003. [185] Patrick Doherty. 2004. Advanced Research with Autonomous Unmanned Aerial Vehicles. In Proceedings of the 9th International Conference on the Principles of Knowledge Representation and Reasoning, pages 731–732. AAAI Press. ISBN: 978-1-57735-199-3. The emerging area of intelligent unmanned aerial vehicle (UAV) research has shown rapid development in recent years and offers a great number of research challenges for artificial intelligence and knowledge representation. For both military and civilian applications, there is a desire to develop more sophisticated UAV platforms where the emphasis is placed on intelligent capabilities and their integration in complex distributed software architectures. Such architectures should support the integration of deliberative, reactive and control functionalities in addition to the UAV’s integration with larger network centric systems. In my talk I will present some of the research and results from a long term basic research project with UAVs currently being pursued at Linköping University, Sweden. The talk will focus on knowledge representation techniques used in the project and the support for these techniques provided by the software architecture developed for our UAV platform, a Yamaha RMAX helicopter. Additional focus will be placed on some of the planning and execution monitoring functionality developed for our applications in the areas of traffic monitoring, surveying and photogrammetry and emergency services assistance. [184] Per Olof Pettersson and Patrick Doherty. 2004. Probabilistic Roadmap Based Path Planning for an Autonomous Unmanned Aerial Vehicle. In ICAPS-04 Workshop on Connecting Planning Theory with Practice,2004, pages 49–55. [183] H.Joe Steinhauer. 2004. The Qualitative Description of Traffic Maneuvers. In ECAI Workshop on Spatial and Temporal Reasoning,2004, pages 141–148. [182] Patrick Doherty, Patrik Haslum, Fredrik Heintz, Torsten Merz, Per Nyblom, Tommy Persson and Bjrn Wingman. 2004. A Distributed Architecture for Autonomous Unmanned Aerial Vehicle Experimentation. In 7th International Symposium on Distributed Autonomous Robotic Systems,2004. LAAS. [181] Fredrik Heintz and Patrick Doherty. 2004. Managing Dynamic Object Structures using Hypothesis Generation and Validation. In AAAI Workshop on Anchoring Symbols to Sensor Data,2004, pages 54–62. AAAI Press. [180] Fredrik Heintz and Patrick Doherty. 2004. DyKnow: A Framework for Processing Dynamic Knowledge and Object Structures in Autonomous Systems. In Barbara Dunin-Keplicz, Andrzej Jankowski, Andrzej Skowron, Marcin Szczuka, editors, Proceedings of the International Workshop on Monitoring, Security, and Rescue Techniques in Multi-Agent Systems (MSRAS), pages 479–492. In series: Advances in Soft Computing #28. Springer. ISBN: 978-3540232452. DOI: 10.1007/3-540-32370-8_37. Any autonomous system embedded in a dynamic and changing environment must be able to create qualitative knowledge and object structures representing aspects of its environment on the fly from raw or preprocessed sensor data in order to reason qualitatively about the environment. These structures must be managed and made accessible to deliberative and reactive functionalities which are dependent on being situationally aware of the changes in both the robotic agent’s embedding and internal environment. DyKnow is a software framework which provides a set of functionalities for contextually accessing, storing, creating and processing such structures. The system is implemented and has been deployed in a deliberative/reactive architecture for an autonomous unmanned aerial vehicle. The architecture itself is distributed and uses real-time CORBA as a communications infrastructure. We describe the system and show how it can be used in execution monitoring and chronicle recognition scenarios for UAV applications. [179] Torsten Merz. 2004. Building a System for Autonomous Aerial Robotics Research. In Proceedings of the 5th IFAC Symposium on Intelligent Autonomous Vehicles (IAV). Elsevier. ISBN: 008-044237-4. [178] Gianpaolo Conte, Simone Duranti and Torsten Merz. 2004. Dynamic 3D path following for an autonomous helicopter. In Proceedings of the 5th IFAC Symposium on Intelligent Autonomous Vehicles (IAV). Elsevier. ISBN: 008-044237-4. Link to Licentiate Thesis: http://urn.kb.se/resolve?urn=urn:nbn:se:... A hybrid control system for dynamic path following for an autonomous helicopter is described. The hierarchically structured system combines continuous control law execution with event-driven state machines. Trajectories are defined by a sequence of 3D path segments and velocity profiles, where each path segment is described as a parametric curve. The method can be used in combination with a path planner for flying collision-free in a known environment. Experimental flight test results are shown. [177] Patrick Doherty, Steven Kertes, Martin Magnusson and Andrzej Szalas. 2004. Towards a Logical Analysis of Biochemical Reactions (Extended abstract). In Ramon López de Mántaras, Lorenza Saitta, editors, Proceedings of the 16th European Conference on Artificial Intelligence (ECAI), pages 997–998. IOS Press. ISBN: 1-58603-452-9. We provide a logical model of biochemical reactions and show how hypothesis generation using weakest sufficient and strongest necessary conditions may be used to provide additional information in the context of an incomplete model of metabolic pathways. [176] Patrick Doherty, Witold Lukaszewicz and Andrzej Szalas. 2004. Approximate Databases and Query Techniques for Agents with Heterogenous Perceptual Capabilities. In Proceedings of the 7th International Conference on Information Fusion, pages 175–182. ISIF. ISBN: 91-7056-115-X. In this paper, we propose a framework that provides software and robotic agents with the ability to ask approximate questions to each other in the context of heterogeneous and contextually limited perceptual capabilities. The framework focuses on situations where agents have varying ability to perceive their environments. These limitations on perceptual capability are formalized using the idea of tolerance spaces. It is assumed that each agent has one or more approximate databases where approximate relations are represented using intuitions from rough set theory. It is shown how sensory and other limitations can be taken into account when constructing approximate databases for each respective agent. Complex relations inherit the approximativeness inherent in the sensors and primitive relations used in their definitions. Agents then query these databases and receive answers through the filters of their perceptual limitations as represented by tolerance spaces and approximate queries. The techniques used are all tractable. [175] Patrick Doherty and Andrzej Szalas. 2004. On the Correspondence between Approximations and Similarity. In Shusaku Tsumoto, Roman Slowinski, Jan Komorowski and Jerzy W. Grzymala-Busse, editors, Proceedings of the International Conference on Rough Sets and Current Trends in Computing (RSCTC), pages 143–152. In series: Lecture Notes in Computer Science #3066. Springer. DOI: 10.1007/978-3-540-25929-9_16. This paper focuses on the use and interpretation of approximate databases where both rough sets and indiscernibility partitions are generalized and replaced by approximate relations and similarity spaces. Similarity spaces are used to define neighborhoods around individuals and these in turn are used to define approximate sets and relations. There is a wide spectrum of choice as to what properties the similarity relation should have and how this affects the properties of approximate relations in the database. In order to make this interaction precise, we propose a technique which permits specification of both approximation and similarity constraints on approximate databases and automatic translation between them. This technique provides great insight into the relation between similarity and approximation and is similar to that used in modal correspondence theory. In order to automate the translations, quantifier elimination techniques are used. [174] Patrick Doherty, Witold Lukaszewicz and Andrzej Szalas. 2004. Approximative Query Techniques for Agents with Heterogeneous Ontologies and Perceptive Capabilities. In Didier Dubois, Christopher A. Welty, Mary-Anne Williams, editors, Proceedings of the 9th International Conference on the Principles of Knowledge Representation and Reasoning, pages 459–468. AAAI Press. ISBN: 978-1-57735-199-3. In this paper, we propose a framework that provides software and robotic agents with the ability to ask approximate questions to each other in the context of heterogeneous ontologies and heterogeneous perceptive capabilities.The framework combines the use of logic-based techniques with ideas from approximate reasoning. Initial queries by an agent are transformed into approximate queries using weakest sufficient and strongest necessary conditions on the query and are interpreted as lower and upper approximations on the query. Once the base communication ability is provided, the framework is extended to situations where there is not only a mismatch between agent ontologies, but the agents have varying ability to perceive their environments. This will affect each agent’s ability to ask and interpret results of queries. Limitations on perceptive capability are formalized using the idea of tolerance spaces. [173] Patrick Doherty, Jaroslaw Kachniarz and Andrzej Szalas. 2004. Using Contextually Closed Queries for Local Closed-World Reasoning in Rough Knowledge Databases. In Andrzej Skowron,Lech Polkowski ,Sankar K Pal, editors, Rough-Neural Computing: Techniques for Computing with Words, pages 219–250. In series: Cognitive Technologies #??. Springer. ISBN: 978-3-540-43059-9, 35-4043-059-8. find book at a swedish library/hitta boken i ett svenskt bibliotek: http://libris.kb.se/bib/14144444 find book in another country/hitta boken i ett annat land: http://www.worldcat.org/title/rough-neur... Soft computing comprises various paradigms dedicated to approximately solving real-world problems, e.g., in decision making, classification or learning; among these paradigms are fuzzy sets, rough sets, neural networks, and genetic algorithms.It is well understood now in the soft computing community that hybrid approaches combining various paradigms provide very promising attempts to solving complex problems. Exploiting the potential and strength of both neural networks and rough sets, this book is devoted to rough-neurocomputing which is also related to the novel aspect of computing based on information granulation, in particular to computing with words. It provides foundational and methodological issues as well as applications in various fields. [172] Patrick Doherty, Witold Lukaszewicz, Andrzej Skowron and Andrzej Szalas. 2004. Approximation Transducers and Trees: A Technique for Combining Rough and Crisp Knowledge. In Andrzej Skowron,Lech Polkowski ,Sankar K Pal, editors, Rough-Neural Computing: Techniques for Computing with Words, pages 189–218. In series: Cognitive Technologies #??. Springer. ISBN: 978-3-540-43059-9, 35-4043-059-8. find book at a swedish library/hitta boken i ett svenskt bibliotek: http://libris.kb.se/bib/14144444 find book in another country/hitta boken i ett annat land: http://www.worldcat.org/search?qt=worldc... Soft computing comprises various paradigms dedicated to approximately solving real-world problems, e.g., in decision making, classification or learning; among these paradigms are fuzzy sets, rough sets, neural networks, and genetic algorithms.It is well understood now in the soft computing community that hybrid approaches combining various paradigms provide very promising attempts to solving complex problems. Exploiting the potential and strength of both neural networks and rough sets, this book is devoted to rough-neurocomputing which is also related to the novel aspect of computing based on information granulation, in particular to computing with words. It provides foundational and methodological issues as well as applications in various fields. [171] Patrik Haslum. 2004. Improving Heuristics Through Search. In Ramon López de Mántaras, Lorenza Saitta, editors, Proceedings of the 16th Eureopean Conference on Artificial Intelligence (ECAI), pages 1031–1032. IOS Press. ISBN: 1-58603-452-9. We investigate two methods of using limited search to improve admissible heuristics for planning, similar to pattern databases and pattern searches. We also develop a new algorithm for searching AND/OR graphs 2003 [170] Eva-Lena Lengquist Sandelin, Susanna Monemar, Peter Fritzson and Peter Bunus. 2003. DrModelica - An Interactive Environment for Learning Modelica and Modeling using MathModelica. In . This paper states the need for interactive teaching materials for programming languages within the area of modeling and simulation. We propose an interactive teaching material for the modeling language Modelica inspired by existing tutoring systems for Java and Scheme. The purpose of this new teaching material, called DrModelica, is to facilitate the learning of Modelica through an environment that integrates programming, program documentation and visualization. The teaching material is intended to be used for modeling and simulation related courses at the undergraduate and graduate level. [169] Patrick Doherty, W. Lukaszewicz, Skowron Andrzej and Andrzej Szalas. 2003. Knowledge Representation and Approximate Reasoning. Conference Proceedings. In series: Fundamenta Informaticae #2003(57):2-4. IOS Press. Note: Special Issue [168] Madelaine Engstrm, Anders Haraldsson, Tove Mattsson and Minna Salminen-Karlsson. 2003. Studenter genusgranskar sin utbildning: Projekt med elektro- och dataprogrammen och lrarutbildningen vid Linkpings universitet. Technical Report. In series: CUL-rapporter #2003:5. Linkping University Electronic Press. 56 pages. I huvudsak kvinnliga studenter från elektro- och dataprogrammen och lä-rarutbildningen utbildades i genuskunskap och fick i uppdrag att under ett läsår studera sina utbildningar ur ett genusperspektiv gällande inne-håll, kurslitteratur, undervisnings- och examinationsformer samt bemö-tande från lärare och andra studenter. Studenterna från respektive utbild-ningsområde bildade var sin projektgrupp under ledning av en handledare.De huvudsakliga resultaten är dels att de kvinnliga studenterna efter utbildningen i genuskunskap och alla diskussioner ser sina utbildningar på ett nytt sätt, genom att självmant observera och reflektera över förete-elser de inte varit medvetna om. Dels har vi fått ökad kunskap om genus-aspekter i själva utbildningsprogrammen genom de observationer som studenterna gjort under läsåret. Dessutom kan man se projektet som en mall för andra program som man vill studera och genomlysa ur ett ge-nusperspektiv. Ett annat intressant resultat från projektet var bildandet av det kvinnliga nätverket Grace för elektro- och datastudenterna.Rapporten beskriver projektet, dess uppläggning och genomförande, re-sultaten från respektive utbildningsområde och avslutas med en reflektion av projektet och de funna resultaten i ett större perspektiv med jämförelser med resultat från andra undersökningar om genus i högskoleutbildning. [167] Eva-Lena Lengquist Sandelin, Susanna Monemar, Peter Fritzson and Peter Bunus. 2003. DrModelica - A Web-Based Teaching Environment for Modelica. In Proceedings of the 44th Conference on Simulation and Modeling (SIMS). Malardalen University. ISBN: 91-631-4716-5. This paper states the need for interactive teaching materials for programming languages within the area of modeling and simulation. We propose an interactive teaching material for the modeling language Modelica inspired by existing tutoring systems for Java and Scheme.The purpose of this new teaching material, called DrModelica, is to facilitate the learning of Modelica in a modeling and simulation environment. We have developed two versions of DrModelica, one that is based on Mathematica and another that is intended for the web. With the web version of DrModelica we hope for an increased usage of Modelica. [166] Eva-Lena Lengquist Sandelin, Susanna Monemar, Peter Fritzson and Peter Bunus. 2003. DrModelica - An Interactive Tutoring Environment for Modelica. In Proceedings of the 3rd International Modelica Conference. Modelica Association. This paper states the need for interactive teaching materials for programming languages within the area of modeling and simulation. We propose an interactive teaching material for the modeling language Modelica inspired by existing tutoring systems for Java and Scheme.The purpose of this new teaching material, called DrModelica, is to facilitate the learning of Modelica through an environment that integrates programming, program documentation and visualization. The teaching material is intended to be used for modeling and simulation related courses at the undergraduate and graduate level. [165] Erik Sandewall, Patrick Doherty, Oliver Lemon and Stanley Peters. 2003. Words at the Right Time: Real-Time Dialogues with the WITAS Unmanned Aerial Vehicle. In Proceedings of the 26th German Conference on Artificial Intelligence (KI), pages 52–63. In series: Lecture Notes in Computer Science #2821. Springer Verlag. DOI: 10.1007/978-3-540-39451-8_5. The WITAS project addresses the design of an intelligent, autonomous UAV (Unmanned Aerial Vehicle), in our case a helicopter. Its dialogue-system subprojects address the design of a deliberative system for natural-language and graphical dialogue with that robotic UAV. This raises new issues both for dialogue and for reasoning in real time. The following topics have been particularly important for us in various stages of the work in these subprojects: - spatiotemporal reference in the dialogue, including reference to past events and to planned or expected, future events - mixed initiative in the dialogue architecture of a complex system consisting of both dialogue-related components (speech, grammar, etc) and others (simulation, event recognition, interface to robot) and more recently as well - identification of a dialogue manager that is no more complex than what is required by the application - uniform treatment of different types of events, including the robot's own actions, observed events, communication events, and dialogue-oriented deliberation events - a logic of time, action, and spatiotemporal phenomena that facilitates the above. This paper gives a brief overview of the WITAS project as a whole, and then addresses the approaches that have been used and that are presently being considered in the work on two generations of dialogue subsystems. [164] Andrzej Szalas. 2003. On a logical approach to estimating computational complexity of potentially intractable problems. In G. Goos, J. Hartmanis, and J. van Leeuwen, editors, Proceedings of the 14th International Symposium on Fundamentals of Computation Theory (FCT), pages 423–431. In series: Lecture Notes in Computer Science #2751. Springer. DOI: 10.1007/978-3-540-45077-1_39. In the paper we present a purely logical approach to estimating computational complexity of potentially intractable problems. The approach is based on descriptive complexity and second-order quantifier elimination techniques. We illustrate the approach on the case of the transversal hypergraph problem, TRANSHYP, which has attracted a great deal of attention. The complexity of the problem remains unsolved for over twenty years. Given two hypergraphs, G and H, TRANSHYP depends on checking whether G = H-d, where H-d is the transversal hypergraph of H. In the paper we provide a logical characterization of minimal transversals of a given hypergraph and prove that checking whether G subset of or equal to H-d is tractable. For the opposite inclusion the Problem still remains open. However, we interpret the resulting quantifier sequences in terms of determinism and bounded nondeterminism. The results give better upper bounds than those known from the literature, e.g., in the case when hypergraph H, has a sub-logarithmic number of hyperedges and (for the deterministic case) all hyperedges have the cardinality bounded by a function sub-linear wrt maximum of sizes of G and H. [163] Jonas Kvarnstrm and Martin Magnusson. 2003. TALplanner in the Third International Planning Competition: Extensions and control rules. The journal of artificial intelligence research, 20(??):343–377. AAAI Press. DOI: 10.1613/jair.1189. TALplanner is a forward-chaining planner that relies on domain knowledge in the shape of temporal logic formulas in order to prune irrelevant parts of the search space. TALplanner recently participated in the third International Planning Competition, which had a clear emphasis on increasing the complexity of the problem domains being used as benchmark tests and the expressivity required to represent these domains in a planning system. Like many other planners, TALplanner had support for some but not all aspects of this increase in expressivity, and a number of changes to the planner were required. After a short introduction to TALplanner, this article describes some of the changes that were made before and during the competition. We also describe the process of introducing suitable domain knowledge for several of the competition domains. [162] Patrick Doherty, Andrew Skowron, Witold Lukaszewicz and Andrzej Szalas. 2003. Preface. Fundamenta Informaticae, 57(2-4):i–iii. IOS Press. [161] E Madalinska-Bugaj and Witold Lukaszewicz. 2003. Formalizing defeasible logic in CAKE. Fundamenta Informaticae, 57(2-3):193–213. IOS Press. Due to its efficiency, defeasible logic is one of the most interesting non-monotonic formalisms. Unfortunately, the logic has one major limitation: it does not properly deal with cyclic defeasible rules. In this paper, we provide a new variant of defeasible logic, using CAKE method. The resulting formalism is tractable and properly deals with circular defeasible rules. [160] Patrick Doherty, M Grabowski, Witold Lukaszewicz and Andrzej Szalas. 2003. Towards a framework for approximate ontologies. Fundamenta Informaticae, 57(2-4):147–165. IOS Press. Currently, there is a great deal of interest in developing tools for the generation and use of ontologies on the WWW. These knowledge structures are considered essential to the success of the semantic web, the next phase in the evolution of the WWW. Much recent work with ontologies assumes that the concepts used as building blocks are crisp as opposed to approximate. It is a premise of this paper that approximate concepts and ontologies will become increasingly more important as the semantic web becomes a reality. We propose a framework for specifying, generating and using approximate ontologies. More specifically, (1) a formal framework for defining approximate concepts, ontologies and operations on approximate concepts and ontologies is presented. The framework is based on intuitions from rough set theory, (2) algorithms for automatically generating approximate ontologies from traditional crisp ontologies or from large data sets together with additional knowledge are presented. The knowledge will generally be related to similarity measurements between individual objects in the data sets, or constraints of a logical nature which rule out particular constellations of concepts and dependencies in generated ontologies. The techniques for generating approximate ontologies are parameterizable. The paper provides specific instantiations and examples. [159] Patrick Doherty, Witold Lukaszewicz and Andrzej Szalas. 2003. On mutual understanding among communicating agents. In B. Dunin-Keplicz and R. Verbrugge, editors, Proceedings of the International Workshop on Formal Approaches to Multi-Agent Systems (FAMAS), pages 83–97. [158] Patrick Doherty and et al. 2003. 2003 AAAI Spring Symposium Series. The AI Magazine, 24(3):131–140. AAAI Press. The American Association for Artificial Intelligence, in cooperation with Stanford University’s Department of Computer Science, presented the 2003 Spring Symposium Series, Monday through Wednesday, 24–26 March 2003, at Stanford University. The titles of the eight symposia were Agent-Mediated Knowledge Management, Computational Synthesis: From Basic Building Blocks to High- Level Functions, Foundations and Applications of Spatiotemporal Reasoning (FASTR), Human Interaction with Autonomous Systems in Complex Environments, Intelligent Multimedia Knowledge Management, Logical Formalization of Commonsense Reasoning, Natural Language Generation in Spoken and Written Dialogue, and New Directions in Question-Answering Motivation. [157] Igor S. Pandzic, Jrgen Ahlberg, Mariusz Wzorek, Piotr Rudol and Miran Mosmondor. 2003. Faces Everywhere: Towards Ubiquitous Production and Delivery of Face Animation. In Proceedings of the 2nd International Conference on Mobile and Ubiquitous Multimedia (MUM), pages 49–56. In series: Linkping Electronic Conference Proceedings #11. Linkping University Electronic Press. Link: http://www.ep.liu.se/ecp/011/010/ecp0110... While face animation is still considered one of the toughesttasks in computer animation, its potential application range israpidly moving from the classical field of film production intogames, communications, news delivery and commerce. Tosupport such novel applications, it is important to enableproduction and delivery of face animation on a wide range ofplatforms, from high-end animation systems to the web, gameconsoles and mobile phones. Our goal is to offer a frameworkof tools interconnected by standard formats and protocols andcapable of supporting any imaginable application involvingface animation with the desired level of animation quality,automatic production wherever it is possible, and delivery ona wide range of platforms. While this is clearly an ongoingtask, we present the current state of development along withseveral case studies showing that a wide range of applicationsis already enabled. [156] Erik Johan Sandewall. 2003. High-level design of WWW servers in Allegro Common Lisp. In Proceedings of the International Lisp Conference (ILC). When invoking a function or a procedure in an ordinary programming language, it is normally assumed that the arguments may be given as composite expressions, and that they are not restricted to atomic constants or variable symbols. However, although active web pages in HTML-based web servers can be viewed as a kind of procedures, they do not enjoy the same flexibility. The present paper reports on a software package that extends the embedded web server in the ACL (Allegro Common Lisp) system and that provides it with the kind of functional flavor just described. In passing, the software also adds a number of other convenience measures to the LHTML (Lisp-encoded HTML) of the ACL server. [155] Erik Johan Sandewall. 2003. A software architecture for AI systems based on self-modifying software individuals. In Proceedings of the International Lisp Conference (ILC). The Software Individuals Architecture (SIA) is a framework fordefining software systems that are capable of self-modification and of reproductionon the level of an interpretive programming language. In abstractterms, a self-modifying system is a labelled tree containing scripts at someof its nodes; these scripts are effectively programs. A computation in sucha system executes a specific script. In doing so it maintains a local computationalstate, but it also uses and updates the labelled tree. The labelledtree, the local computational state, and the command language used for thescripts are all designed in such a way as to support self-modification andreproduction in a structured and orderly fashion.We have defined a practical system of this kind both on an abstract andformal level and as an implementation using Lisp as the host language. Thisarchitecture has been used as a platform for several applications, including inparticular the speech and natural-language dialogue system for an intelligentautonomous unmanned aerial vehicle (UAV) in the WITAS project. Thearchitecture design has been revised repeatedly as a result of using it for thisapplication as well as several others. [154] Patrick Doherty, Witold Lukaszewicz and Andrzej Szalas. 2003. Tolerance Spaces and Approximative Representational Structures. In Proceedings of the 26th German Conference on Artificial Intelligence (KI), pages 475–489. In series: Lecture Notes in Computer Science #2821. Springer. DOI: 10.1007/978-3-540-39451-8_35. In traditional approaches to knowledge representation, notions such as tolerance measures on data, distance between objects or individuals, and similarity measures between primitive and complex data structures are rarely considered. There is often a need to use tolerance and similarity measures in processes of data and knowledge abstraction because many complex systems which have knowledge representation components such as robots or software agents receive and process data which is incomplete, noisy, approximative and uncertain. This paper presents a framework for recursively constructing arbitrarily complex knowledge structures which may be compared for similarity, distance and approximativeness. It integrates nicely with more traditional knowledge representation techniques and attempts to bridge a gap between approximate and crisp knowledge representation. It can be viewed in part as a generalization of approximate reasoning techniques used in rough set theory. The strategy that will be used is to define tolerance and distance measures on the value sets associated with attributes or primitive data domains associated with particular applications. These tolerance and distance measures will be induced through the different levels of data and knowledge abstraction in complex representational structures. Once the tolerance and similarity measures are in place, an important structuring generalization can be made where the idea of a tolerance space is introduced. Use of these ideas is exemplified using two application domains related to sensor modeling and communication between agents. [153] Patrick Doherty, Witold Lukaszewicz and Andrzej Szalas. 2003. Information Granules for Intelligent Knowledge Structures. In Guoyin Wang, Qing Liu, Yiyu Yao, Andrzej Skowron, editors, Proceedings of the 9th International Conference on Rough Sets, Fuzzy Sets, Data Mining and Granular Computing (RSFDGrC), pages 405–412. In series: Lecture Notes in Computer Science #2639. Springer. ISBN: 978-3-540-14040-5. DOI: 10.1007/3-540-39205-X_68. The premise of this paper is that the acquisition, aggregation, merging and use of information requires some new ideas, tools and techniques which can simplify the construction, analysis and use of what we call ephemeral knowledge structures. Ephemeral knowledge structures are used and constructed by granular agents. Each agent contains its own granular information structure and granular information structures of agents can be combined together. The main concept considered in this paper is an information granule. An information granule is a concise conceptual unit that can be integrated into a larger information infrastructure consisting of other information granules and dependencies between them. The novelty of this paper is that it provides a concise and formal definition of a particular view of information granule and its associated operators, as required in advanced knowledge representation applications. [152] Patrik Haslum and Ulrich Scholz. 2003. Domain Knowledge in Planning: Representation and Use. In Proceedings of the ICAPS workshop on PDDL, pages 69–78. Planning systems rely on knowledge about the problems they have to solve: The problem description and in many cases advice on how to find a solution. This paper is concerned with a third kind of knowledge which we term domain knowledge: Information about the problem that is produced by one component of the planner and used for advice by another. We first distinguish domain knowledge from the problem description and from advice, and argue for the advantages of the explict use of domain knowledge. Then we identify three classes of domain knowledge for which these advantages are most apparent and define a language, DKEL, to represent these classes. DKEL is designed as an extension to PDDL. [151] Anders Arpteg. 2003. Adaptive Semi-structured Information Extraction. Licentiate Thesis. In series: Linkping Studies in Science and Technology. Thesis #1000. Institutionen fr datavetenskap. 85 pages. ISBN: 91-7373-589-2. Note: Report code: LiU-Tek-Lic-2002:73. The number of domains and tasks where information extraction tools can be used needs to be increased. One way to reach this goal is to construct user-driven information extraction systems where novice users are able to adapt them to new domains and tasks. To accomplish this goal, the systems need to become more intelligent and able to learn to extract information without need of expert skills or time-consuming work from the user.The type of information extraction system that is in focus for this thesis is semistructural information extraction. The term semi-structural refers to documents that not only contain natural language text but also additional structural information. The typical application is information extraction from World Wide Web hypertext documents. By making effective use of not only the link structure but also the structural information within each such document, user-driven extraction systems with high performance can be built.The extraction process contains several steps where different types of techniques are used. Examples of such types of techniques are those that take advantage of structural, pure syntactic, linguistic, and semantic information. The first step that is in focus for this thesis is the navigation step that takes advantage of the structural information. It is only one part of a complete extraction system, but it is an important part. The use of reinforcement learning algorithms for the navigation step can make the adaptation of the system to new tasks and domains more user-driven. The advantage of using reinforcement learning techniques is that the extraction agent can efficiently learn from its own experience without need for intensive user interactions.An agent-oriented system was designed to evaluate the approach suggested in this thesis. Initial experiments showed that the training of the navigation step and the approach of the system was promising. However, additional components need to be included in the system before it becomes a fully-fledged user-driven system. 2002 [150] Patrik Haslum. 2002. Partial State Progression: An Extension to the Bacchus-Kabanza Algorithm, with Applications to Prediction and MITL Consistency. In Proceedings of the AIPS 2002 workshop on Planning via Model Checking. [149] Jonas Kvarnstrm. 2002. Applying Domain Analysis Techniques for Domain-Dependent Control in TALplanner. In Malik Ghallab, Joachim Hertzberg, and Paolo Traverso, editors, Proceedings of the 6th International Conference on Artificial Intelligence Planning and Scheduling (AIPS). AAAI Press. ISBN: 0-57735-142-8. DOI: 10.3233/978-1-60750-606-5-341. A number of current planners make use of automatic domain analysis techniques to extract information such as state invariants or necessary goal orderings from a planning domain. There are also planners that allow the user to explicitly specify additional information intended to improve performance. One such planner is TALplanner, which allows the use of domain-dependent temporal control formulas for pruning a forward-chaining search tree. This leads to the question of how these two approaches can be combined. In this paper we show how to make use of automatically generated state invariants to improve the performance of testing control formulas. We also develop a new technique for analyzing control rules relative to control formulas and show how this often allows the planner to automatically strengthen the preconditions of the operators, thereby reducing time complexity and improving the performance of TALplanner by a factor of up to 400 for the largest problems from the AIPS-2000 competition. [148] Erik Skarman and AB Saab. 2002. EEG waves as chaotic self-oscillations. In International Journal of Psychophysiology, pages 138–138. [147] Erik Johan Sandewall. 2002. Use of cognitive robotics logic in a double helix architecture for autonomous systems. In Advances in Plan-Based Control of Robotic Agents: Revised Papers from the International Seminar at Dagstuhl Castle, pages 226–248. In series: Lecture Notes in Computer Science #2466. Springer. DOI: 10.1007/3-540-37724-7_14. This paper addresses the two-way relation between the architecture for cognitive robots on one hand, and a logic of action and change that is adapted to the needs of such robots on the other hand. The relation goes both ways: the logic is used within the architecture, but we also propose that an abstract model of the cognitive robot architecture shall be used for defining the semantics of the logic. For this purpose, we describe a novel architecture called the Double Helix Architecture which, unlike earlier proposals, emphasizes a precise account of the metric discrete timeline and the computational processes that take place along that timeline. The computational model of the Double Helix Architecture corresponds to the semantics of the logic being used, namely the author's Cognitive Robotics Logic which is based on the 'Features and Fluents' theory. [146] Andrzej Szalas. 2002. Second-order quantifier elimination in modal contexts. In Sergio Flesca, Sergio Greco, Nicola Leone, Giovambattista Ianni, editors, Proceedings of the 8th European Conference on Logics in Artificial Intelligence (JELIA), pages 223–232. In series: Lecture Notes in Computer Science #2424. Springer. ISBN: 978-354044190-8. DOI: 10.1007/3-540-45757-7_19. Second-order quantifier elimination in the context of classical logic emerged as a powerful technique in many applications, including the correspondence theory, relational databases, deductive and knowledge databases, knowledge representation, commonsense reasoning and approximate reasoning. In the current paper we generalize the result of [19] by allowing modal operators. This allows us to provide a unifying framework for many applications, that require the use of intensional concepts. Examples of applications of the technique in AI are also provided. [145] John-Jules Meyer and Patrick Doherty. 2002. Preferential Action Semantics. In John-Jules Ch Meyer; Jan Treur, editor, Handbook of Defeasible Reasoning and Uncertainty Management Systems: Volume 7:: Agent-Based Defeasible Control in Dynamic Environments. In series: Handbook of Defeasible Reasoning and Uncertainty Management Systems #7. Kluwer. ISBN: 978-1-4020-0834-4, 14-02-0-0834-1. find book in another country/hitta boken i ett annat land: http://www.worldcat.org/search?q=Handboo... This last volume of the Handbook of Defeasible Reasoning and Uncertainty Management Systems is - together with Volume 6 - devoted to the topics Reasoning and Dynamics, covering both the topics of \"Dynamics of Reasoning,\" where reasoning is viewed as a process, and \"Reasoning about Dynamics,\" which must be understood as pertaining to how both designers of, and agents within dynamic systems may reason about these systems. The present volume presents work done in this context and is more focused on \"reasoning about dynamics,\" viz. how (human and artificial) agents reason about (systems in) dynamic environments in order to control them. In particular modelling frameworks and generic agent models for modelling these dynamic systems and formal approaches to these systems such as logics for agents and formal means to reason about agent-based and compositional systems, and action & change more in general are considered. [144] Klas Nordberg, Patrick Doherty, Gunnar Farnebck, Per-Erik Forssn, Gsta Granlund, Anders Moe and Johan Wiklund. 2002. Vision for a UAV helicopter. In International Conference on Intelligent Robots and Systems (IROS), Workshop on Aerial Robotics: Lausanne, Switzerland. This paper presents and overview of the basic and applied research carried out by the Computer Vision Laboratory, Linköping University, in the WITAS UAV Project. This work includes customizing and redesigning vision methods to fit the particular needs and restrictions imposed by the UAV platform, e.g., for low-level vision, motion estimation, navigation, and tracking. It also includes a new learning structure for association of perception-action activations, and a runtime system for implementation and execution of vision algorithms. The paper contains also a brief introduction to the WITAS UAV Project. [143] Patrick Doherty, Witold Lukaszewicz and Andrzej Szalas. 2002. CAKE: A computer aided knowledge engineering technique. In Frank van Harmelen, editor, Proceedings of the 15th European Conference on Artificial Intelligence,2002, pages 220–224. IOS Press. Introduction: Logic engineering often involves the development of modeling tools and inference mechanisms (both standard and non-standard) which are targeted for use in practical applications where expressiveness in representation must be traded off for efficiency in use. Some representative examples of such applications would be the structuring and querying of knowledge on the semantic web, or the representation and querying of epistemic states used with softbots, robots or smart devices. In these application areas, declarative representations of knowledge enhance the functionality of such systems and also provide a basis for insuring the pragmatic properties of modularity and incremental composition. In addition, the mechanisms developed should be tractable, but at the same time, expressive enough to represent such aspects as default reasoning, or approximate or incomplete representations of the environments in which the entities in question are embedded or used, be they virtual or actual. [...] [142] Per Andersson, Krzysztof Kuchcinski, Klas Nordberg and Patrick Doherty. 2002. Integrating a computational model and a run time system for image processing on a UAV. In Euromicro Symposium on Digital System Design (DSD), pages 102–109. DOI: 10.1109/DSD.2002.1115357. Recently substantial research has been devoted to Unmanned Aerial Vehicles (UAVs). One of a UAV's most demanding subsystem is vision. The vision subsystem must dynamically combine different algorithms as the UAVs goal and surrounding change. To fully utilize the available hardware, a run time system must be able to vary the quality and the size of regions the algorithms are applied to, as the number of image processing tasks changes. To allow this the run time system and the underlying computational model must be integrated. In this paper we present a computational model suitable for integration with a run time system. The computational model is called Image Processing Data Flow Graph (IP-DFG). IP-DFG has been developed for modeling of complex image processing algorithms. IP-DFG is based on data flow graphs, but has been extended with hierarchy and new rules for token consumption, which makes the computational model more flexible and more suitable for human interaction. In this paper we also show that IP-DFGs are suitable for modelling expressions, including data dependent decisions and iterations, which are common in complex image processing algorithms. [141] Patrik Haslum. 2002. Prediction as a Knowledge Representation Problem: A Case Study in Model Design. Licentiate Thesis. In series: Linkping Studies in Science and Technology. Thesis #942. Institutionen fr datavetenskap. 106 pages. ISBN: 91-7373-331-8. Note: Report code: LiU-Tek-Lic-2002:15. Link to Ph.D. Thesis: http://urn.kb.se/resolve?urn=urn:nbn:se:... The WITAS project aims to develop technologies to enable an Unmanned Airial Vehicle (UAV) to operate autonomously and intelligently, in applications such as traffic surveillance and remote photogrammetry. Many of the necessary control and reasoning tasks, e.g. state estimation, reidentification, planning and diagnosis, involve prediction as an important component. Prediction relies on models, and such models can take a variety of forms. Model design involves many choices with many alternatives for each choice, and each alternative carries advantages and disadvantages that may be far from obvious. In spite of this, and of the important role of prediction in so many areas, the problem of predictive model design is rarely studied on its own.In this thesis, we examine a range of applications involving prediction and try to extract a set of choices and alternatives for model design. As a case study, we then develop, evaluate and compare two different model designs for a specific prediction problem encountered in the WITAS UAV project. The problem is to predict the movements of a vehicle travelling in a traffic network. The main difficulty is that uncertainty in predictions is very high, du to two factors: predictions have to be made on a relatively large time scale, and we have very little information about the specific vehicle in question. To counter uncertainty, as much use as possible must be made of knowledge about traffic in general, which puts emphasis on the knowledge representation aspect of the predictive model design.The two mode design we develop differ mainly in how they represent uncertainty: the first uses coarse, schema-based representation of likelihood, while the second, a Markov model, uses probability. Preliminary experiments indicate that the second design has better computational properties, but also some drawbacks: model construction is data intensive and the resulting models are somewhat opaque. [140] Bourhane Kadmiry. 2002. Fuzzy Control for an Unmanned Helicopter. Licentiate Thesis. In series: Linkping Studies in Science and Technology. Thesis #938. Institutionen fr datavetenskap. 108 pages. ISBN: 91-7373-313-X. Note: Report code: LiU-Tek-Lic-2002:11. The format of the electronic version of this thesis differs slightly from the printed one: this is due mainly to font compatibility. The figures and body of the thesis are remaining unchanged. The overall objective of the Wallenberg Laboratory for Information Technology and Autonomous Systems (WITAS) at Linköping University is the development of an intelligent command and control system, containing vision sensors, which supports the operation of a unmanned air vehicle (UAV) in both semi- and full-autonomy modes. One of the UAV platforms of choice is the APID-MK3 unmanned helicopter, by Scandicraft Systems AB. The intended operational environment is over widely varying geographical terrain with traffic networks and vehicle interaction of variable complexity, speed, and density.The present version of APID-MK3 is capable of autonomous take-off, landing, and hovering as well as of autonomously executing pre-defined, point-to-point flight where the latter is executed at low-speed. This is enough for performing missions like site mapping and surveillance, and communications, but for the above mentioned operational environment higher speeds are desired. In this context, the goal of this thesis is to explore the possibilities for achieving stable ‘‘aggressive’’ manoeuvrability at high-speeds, and test a variety of control solutions in the APID-MK3 simulation environment.The objective of achieving ‘‘aggressive’’ manoeuvrability concerns the design of attitude/velocity/position controllers which act on much larger ranges of the body attitude angles, by utilizing the full range of the rotor attitude angles. In this context, a flight controller should achieve tracking of curvilinear trajectories at relatively high speeds in a robust, w.r.t. external disturbances, manner. Take-off and landing are not considered here since APIDMK3 has already have dedicated control modules that realize these flight modes.With this goal in mind, we present the design of two different types of flight controllers: a fuzzy controller and a gradient descent method based controller. Common to both are model based design, the use of nonlinear control approaches, and an inner- and outer-loop control scheme. The performance of these controllers is tested in simulation using the nonlinear model of APID-MK3. 2001 [139] Erik Sandewall. 2001. On the Design of Software Individuals. Electronic Transactions on Artifical Intelligence, 5(??):??–??. Linkpings Universitet. [138] Jaroslaw Kachniarz and Andrzej Szalas. 2001. On a Static Approach to Verification of Integrity Constraints in Relational Databases. In Eva Orlowska, Andrzej Szalas, editors, Relational Methods for Computer Science Applications, pages 97–109. In series: Studies in Fuzziness and Soft Computing #65. Springer Physica-Verlag. ISBN: 3-7908-1365-6. Find book at a Swedish library/Hitta boken i ett svenskt bibliotek: http://libris.kb.se/hitlist?d=libris&q=3... Find book in another country/Hitta boken i ett annat land: http://www.worldcat.org/search?q=3-7908-... [137] Ewa Orlowska and Andrzej Szalas. 2001. Relational Methods for Computer Science Applications. In series: Studies in Fuziness and Soft Computing #??. Springer Physica Verlag. 297 pages. ISBN: 37-9081-365-6, 978-37-9081-365-4. Find book in another country/Hitta boken i ett annat land: http://www.worldcat.org/search?q=37-9081... This volume addresses all current aspects of relational methods and their applications in computer science. It presents a broad variety of fields and issues in which theories of relations provide conceptual or technical tools. The contributions address such subjects as relational methods in programming, relational constraints, relational methods in linguistics and spatial reasoning, relational modelling of uncertainty. All contributions provide the readers with new and original developments in the respective fields.The reader thus gets an interdisciplinary spectrum of the state of the art of relational methods and implementation-oriented solutions of problems related to these areas [136] Joakim Gustafsson. 2001. Object-oriented Reasoning about Action and Change. In H.H. Lund, B. Mayoh, J. Perram, editors, Proceedings of the Seventh Scandinavian Conference on Artificial Intelligence (SCAI), pages 53–64. In series: Frontiers in Artificial Intelligence and Applications #66. IOS Press. ISBN: 1-58603-161-9. As the scope of logics of action and change continues to increase and powerful research tools are developed, it becomes possible to model larger and more complex scenarios. Unfortunately the scenarios become harder to read and difficult to modify and debug with increasing size and complexity. These problems have been overlooked in the action and change community due to the fact that only smaller toy problems are considered. Sound modeling methodology is as essential as the primitives of the modeling language. The object-oriented paradigm is one structuring mechanism that alleviates these problems and provides a systematic means of scenario construction. The topic of this paper is to demonstrate how many ideas from the object orientation paradigm can be used when reasoning about action and change, we show this by integrating the technique directly in an existing logic of action and change without any modification to the underlying logical language or semantics. 1 [135] Bourhane Kadmiry, Rainer Palm and Dimiter Driankov. 2001. Autonomous Helicopter Control Using Gradient Descent Optimization Method. In Proceedings of the Asian Conference on Robotic & Automation (ACRA). The work reported in this paper is aimed at designing a velocityyaltitude and position controllers for the unmanned helicopter APID MK-III by Scandicraft AB in Sweden. The controllers are able of regulating high velocities via stabilization of the attitude angles within much larger ranges than currently available. We use a novel approach to the design consisting of two steps: rst, a gradient descent optimization method i s u s e d t o c ompute for each desired horizontal velocityyaltitude or position the corresponding desired values for the attitude angles and the main rotor col-lective pitch; second, a linear control scheme is used to regulate the attitude angles so that the helicopter achieves its desired horizontal velocity at the desired altitude, or its desired position. The performance of the controllers is evaluated in simulation and shows that the proposed design method achieves its intended purpose. [134] Bourhane Kadmiry, Pontus Bergsten and Dimiter Driankov. 2001. Autonomous Helicopter Control Using Fuzzy-Gain Scheduling. In Proceedings of the IEEE International Conference on Robotic & Automation (ICRA), pages 2980–2985. IEEE. ISBN: 0-7803-6576-3. DOI: 10.1109/ROBOT.2001.933074. The work reported in the paper is aimed at achieving aggressive manoeuvrability for an unmanned helicopter APID MK-III by Scandicraft AB in Sweden. The manoeuvrability problem is treated at the level of attitude (pitch, roll, yaw) and the aim is to achieve stabilization of the attitude angles within much larger ranges than currently available. We present a fuzzy gain scheduling control approach based on two different types of Iinearization of the original nonlinear APID MK-III model. The performance of the fuzzy gain scheduled controllers is evaluated in simulation and shows that they are effective means for achieving the desired robust manoeuvrability. [133] Bourhane Kadmiry and Dimiter Driankov. 2001. Fuzzy Control of an Autonomous Helicopter. In Proceedings of the 9th IEEE International Fuzzy Systems Association (IFSA) World Congress, pages 2797–2802. IEEE Computer Society. ISBN: 0-7803-7078-3. DOI: 10.1109/NAFIPS.2001.943669. This work presents a horizontal velocity controller for the unmanned helicopter APID MK-III developed by Scandicraft AB in Sweden. We use a novel approach to the design consisting of two steps: 1) Mamdani-type of fuzzy rules to compute each of the desired horizontal velocity corresponding to the desired values for the attitude angles and the main rotor collective pitch; and 2) a Takagi-Sugeno controller is used to regulate the attitude angles so that the helicopter achieves its desired horizontal velocities at a desired altitude. The performance of the combined linguistic/model-based controller is evaluated in simulation and shows that the proposed design method achieves its intended purpose [132] Bourhane Kadmiry and Dimiter Driankov. 2001. Autonomous Helicopter Control using Linguistic and Model-Based Fuzzy Control. In Proceedings of the IEEE International Symposium on Intelligent Control (CCA/ISIC), pages 348–352. IEEE. ISBN: 0-7803-6722-7. DOI: 10.1109/ISIC.2001.971534. The paper presents the design of a horizontal velocity controller for the unmanned helicopter APID MK-III developed by Scandicraft AB in Sweden. The controller is able of regulating high horizontal velocities via stabilization of the attitude angles within much larger ranges than currently available. We use a novel approach to the design consisting of two steps: 1) a Mamdani-type of a fuzzy rules are used to compute for each desired horizontal velocity the corresponding desired values for the attitude angles and the main rotor collective pitch; and 2) using a nonlinear model of the altitude and attitude dynamics, a Takagi-Sugeno controller is used to regulate the attitude angles so that the helicopter achieves its desired horizontal velocities at a desired altitude. According to our knowledge this is the first time when a combination of linguistic and model-based fuzzy control is used for the control of a complicated plant such as an autonomous helicopter. The performance of the combined linguistic/model-based controllers is evaluated in simulation and shows that the proposed design method achieves its intended purpose [131] Fredrik Heintz, Johan Kummeneje and Paul Scerri. 2001. Using Simulated RoboCup to Teach AI in Undergraduate Education. In Proceedings of the 7th Scandinavian Conference on Artificial Intelligence (SCAI), pages 13–21. In series: Frontiers in Artificial Intelligence and Applications #66. IOS Press. ISBN: 1-58603-161-9. In this paper we argue that RoboCup is a useful tool for the teaching of AI in undergraduate education. We provide case studies, from two Swedish universities, of how RoboCup based AI courses can be implemented using a problem based approach. Although the courses were successful there are significant areas for improvement. Firstly, to help students cope with the complexity of the domain we developed RoboSoc, a general software framework for developing simulated RoboCup agents. Secondly, we propose creating close co-operation between the teachers and researchers at Scandinavian Universities with the aim of increasing the motivation of both students and teachers by providing accessible information and competence. [130] Fredrik Heintz and Patrick Doherty. 2001. Chronicle Recognition in the WITAS UAV Project: A Preliminary Report. In Proceedings of the Swedish AI Society Workshop. This paper describes the chronicle recognition problem and reports its status in the WITAS UAV project. We describe how we use the IxTeT chronicle recognition system to define chronicles (scenarios or situations), like a vehicle passing another vehicle, and how it is incorporated in the WITAS architecture. We also discuss known problems with the current system and possible directions of future research. [129] Patrik Haslum. 2001. Models for Prediction. In Proceedings of the IJCAI 2001 workshop on Planning under Uncertainty and Incomplete Information (PRO-2). Prediction is found to be a part of many more complex reasoning problems, e.g. state estimation, planning and diagnosis. In spite of this, the prediction problem is rarely studied on its own. Yet there appears to be a wide range of choices for the design of the central component in a solution to this problem, the predictive model. We examine some of the alternatives and, as a case study, present two different solutions to a specific prediction problem that we have encountered in the WITAS UAV project. [128] Patrik Haslum and Hctor Geffner. 2001. Heuristic Planning with Time and Resources. In Proceedings of the 6th European Conference on Planning (ECP). We present an algorithm for planning with time and resources based on heuristic search. The algorithm minimizes makespan using an admissible heuristic derived automatically from the problem instance. Estimators for resource consumption are derived in the same way. The goals are twofold: to show the flexibility of the heuristic search approach to planning and to develop a planner that combines expressivity and performance. Two main issues are the definition of regression in a temporal setting and the definition of the heuristic estimating completion time. A number of experiments are presented for assessing the performance of the resulting planner. [127] Joakim Gustafsson and Jonas Kvarnstrm. 2001. Elaboration Tolerance through Object-Orientation. In Proceedings of the 5th Symposium on Logical Formalizations of Commonsense Reasoning (CommonSense). Although many formalisms for reasoning about action and change have been proposed in the literature, their semantic adequacy has primarily been tested using tiny domains that highlight some particular aspect or problem. However, since some of the classical problems are completely or partially solved and since powerful tools are available, it is now necessary to start modeling more complex domains. This paper presents a methodology for handling such domains in a systematic manner using an object-oriented framework and provides several examples of the elaboration tolerance exhibited by the resulting models. [126] Patrick Doherty and Jonas Kvarnstrm. 2001. TALPLANNER - A temporal logic-based planner. The AI Magazine, 22(3):95–102. AAAI Press. TALPLANNER is a forward-chaining planner that utilizes domain-dependent knowledge to control search in the state space generated by action invocation. The domain-dependent control knowledge, background knowledge, plans, and goals are all represented, using,formulas in, a temporal logic called TAL, which has been developed independently as a formalism for specifying agent narratives and reasoning about them. In the Fifth International Artificial Intelligence Planning and Scheduling Conference planning competition, TALPLANNER exhibited impressive performance, winning the Outstanding Performance Award in the Domain-Dependent Planning Competition. In this article, we provide an overview of TALPLANNER. [125] Patrick Doherty, Witold Lukaszewicz and Andrzej Szalas. 2001. Computing strongest necessary and weakest sufficient conditions of first-order formulas. In 17th International Joint Conference on Artificial Intelligence,2001, pages 145–151. Morgan Kaufmann Publishers Inc.. ISBN: 1-55860-812-5, 978-1-558-60812-2. A technique is proposed for computing the weakest sufficient (wsc) and strongest necessary (snc) conditions for formulas in an expressive fragment of first-order logic using quantifier elimination techniques. The efficacy of the approach is demonstrated by using the techniques to compute snc's and wsc's for use in agent communication applications, theory approximation and generation of abductive hypotheses. Additionally, we generalize recent results involving the generation of successor state axioms in the propositional situation calculus via snc's to the first-order case. Subsumption results for existing approaches to this problem and a re-interpretation of the concept of forgetting as a process of quantifier elimination are also provided. [124] Marcus Bjreland. 2001. Model-based execution monitoring. PhD Thesis. In series: Linkping Studies in Science and Technology. Dissertations #688. Linkpings universitet. 153 pages. ISBN: 91-7373-016-5. The task of monitoring the execution of a software-based controller in order to detect, classify, and recover from discrepancies between the actual effects of control actions and the effects predicted by a model, is the topic of this thesis. Model-based execution monitoring is proposed as a technique for increasing the safety and optimality of operation of large and complex industrial process controllers, and of controllers operating in complex and unpredictable environments (such as unmanned aerial vehicles).In this thesis we study various aspects of model-based execution monitoring, including the following:The relation between previous approaches to execution monitoring in Control Theory, Artificial Intelligence and Computer Science is studied and a common conceptual framework for design and analysis is proposed.An existing execution monitoring paradigm, ontological control, is generalized and extended. We also present a prototype implementation of ontological control with a first set of experimental results where the prototype is applied to an actual industrial process control system: The ABB STRESSOMETER cold mill flatness control system.A second execution monitoring paradigm, stability-based execution monitoring, is introduced, inspired by the vast amount of work on the \"stability\" notion in Control Theory and Computer Science.Finally, the two paradigms are applied in two different frameworks. First, in the \"hybrid automata\" framework, which is a state-of-the-art formal modeling framework for hybrid (that is, discrete+continuous) systems, and secondly, in the logical framework of GOLOG and the Situation Calculus. [123] Joakim Gustafsson. 2001. Extending temporal action logic. PhD Thesis. In series: Linkping Studies in Science and Technology. Dissertations #689. Linkpings universitet. 218 pages. ISBN: 91-7373-017-3. An autonomous agent operating in a dynamical environment must be able to perform several \"intelligent\" tasks, such as learning about the environment, planning its actions and reasoning about the effects of the chosen actions. For this purpose, it is vital that the agent has a coherent, expressive, and well understood means of representing its knowledge about the world.Traditionally, all knowledge about the dynamics of the modeled world has been represented in complex and detailed action descriptions. The first contribution of this thesis is the introduction of domain constraints in TAL, allowing a more modular representation of certain kinds of knowledge.The second contribution is a systematic method of modeling different types of conflict handling that can arise in the context of concurrent actions. A new type of fluent, called influence, is introduced as a carrier from cause to actual effect. Domain constraints govern how influences interact with ordinary fluents. Conflicts can be modeled in a number of different ways depending on the nature of the interaction.A fundamental property of many dynamical systems is that the effects of actions can occur with some delay. We discuss how delayed effects can be modeled in TAL using the mechanisms previously used for concurrent actions, and consider a range of possible interactions between the delayed effects of an action and later occurring actions.In order to model larger and more complex domains, a sound modeling methodology is essential. We demonstrate how many ideas from the object-oriented paradigm can be used when reasoning about action and change. These ideas are used both to construct a framework for high level control objects and to illustrate how complex domains can be modeled in an elaboration tolerant manner. 2000 [122] Mark S Frankel, Roger Elliott, Martin Blume, Jean-Manuel Bourgois, Bernt Hugenholtz, Mats G. Lindquist, Sally Morris and Erik Sandewall. 2000. Defining and Certifying Electronic Publication in Science. Learned Publishing, 13(4):251–258. Association of Learned and Professional Society Publishers. Link to article: http://www.ida.liu.se/ext/caisor/archive... [121] Jaroslaw Kachniarz and Andrzej Szalas. 2000. Algorithms based on Symbolic Transformations of Logical Formulas in the RDL Language. In Proceedings of the 2nd Conference on Applications of Computer Science in Mathematics and Economy, pages 101–115. WSIiE, Olsztyn, Poland. [120] Jaroslaw Kachniarz and Andrzej Szalas. 2000. On Rule-Based Approach to the Construction of Logical Transformers. In Proceedings of the 1st International Workshop on Rule-Based Programming (RULE), pages 57–71. Springer Physica-Verlag. [119] Marcus Bjreland and George Fodor. 2000. Execution monitoring of industrial process controllers: an application of Ontological Control. In Prooceedings of the 4th Symposium on Fault Detection, Supervision and Safety for Technical Systems (SAFEPROCESS '00). ISBN: 0080432506. Link: https://getinfo.de/app/Execution-Monitor... [118] Mutsumi Nakamura, Chitta Baral and Marcus Bjreland. 2000. Maintainability: a weaker stabilizability-like notion for high level control of agents. In Proceedings of the 17th National Conference on Artificial Intelligence (AAAI), pages 62–66. AAAI Press. ISBN: 978-0-262-51112-4, 978-1-57735-272-3. Link: http://swepub.kb.se/bib/swepub:oai:DiVA.... The goal of most agents is not just to reach a goal state, but rather also (or alternatively) to put restrictions on its trajectory, in terms of states it must avoid and goals that it must ‘maintain’. This is analogous to the notions of ‘safety’ and ‘stability’ in the discrete event systems and temporal logic community. In this paper we argue that the notion of ‘stability’ is too strong for formulating ‘maintenance’ goals of an agent – in particular, reactive and software agents, and give examples of such agents. We present a weaker notion of ‘maintainability’ and show that our agents which do not satisfy the stability criteria, do satisfy the weaker criteria. We give algorithms to test maintainability, and also to generate control for maintainability. We then develop the notion of ‘supportability’ that generalizes both ‘maintainability’ and ‘stabilizability, develop an automata theory that distinguishes between exogenous and control actions, and develop a temporal logic based on it. [117] Fredrik Heintz, Johan Kummeneje and Paul Scerri. 2000. Simulated RoboCup in University Undergraduate Education. In Proceedings of the Fourth Internation Workshop on RoboCup, pages 309–314. In series: Lecture Notes in Computer Science #2019. Springer Berlin/Heidelberg. ISBN: 978-3-540-42185-6, 978-3-540-45324-6. DOI: 10.1007/3-540-45324-5_31. We argue that RoboCup can be used to improve the teaching of AI in undergraduate education. We give some examples of how AI courses using RoboCup can be implemented using a problem based approach at two different Universities. To reduce the negative aspects found we present a solution, with the aim of easing the burden of grasping the domain of RoboCup for the students, RoboSoc which is a general framework for developing simulated RoboCup agents. [116] Patrik Haslum and Peter Jonsson. 2000. Planning with Reduced Operator Sets. In Steve Chien, Subbarao Kambhampati, Craig A. Knoblock, editors, Proceedings of the 5th International Conference on Artificial Intelligence Planning and Scheduling (AIPS), pages 150–158. AAAI Press. ISBN: 978-1-57735-111-5. Classical propositional STRIPS planning is nothing but the search for a path in the state transition graph induced by the operators in the planning problem. What makes the problem hard is the size and the sometimes adverse structure of this graph. We conjecture that the search for a plan would be more efficient if there were only a small number of paths from the initial state to the goal state. To verify this conjecture, we define the notion of reduced operator sets and describe ways of finding such reduced sets. We demonstrate that some state-of-the-art planners run faster using reduced operator sets. [115] Patrik Haslum and Hctor Geffner. 2000. Admissible Heuristics for Optimal Planning. In Steve Chien, Subbarao Kambhampati, Craig A. Knoblock, editors, Proceedings of the 5th International Conference on Artificial Intelligence Planning and Scheduling (AIPS), pages 140–149. AAAI Press. ISBN: 978-1-57735-111-5. DOI: 10.1609/aimag.v21i4.1536. Note: There is an error in the paper: the condition for commutativity of actions (section "Commutativity Pruning") must also include that neither action adds a precondition of the other. Thus, commutativity is not the same as Graphplan-style "non-interference". Link: http://swepub.kb.se/bib/swepub:oai:DiVA.... hsp and hspr are two recent planners that search the state-space using an heuristic function extracted from Strips encodings. hsp does a forward search from the initial state recomputing the heuristic in every state, while hspr does a regression search from the goal computing a suitable representation of the heuristic only once. Both planners have shown good performance, often producing solutions that are competitive in time and number of actions with the solutions found by Graphplan and sat planners. hsp and hsp r, however, are not optimal planners. This is because the heuristic function is not admissible and the search algorithms are not optimal. In this paper we address this problem. We formulate a new admissible heuristic for planning, use it to guide an ida search, and empirically evaluate the resulting optimal planner over a number of domains. The main contribution is the idea underlying the heuristic that yields not one but a whole family of polynomial and admissible heuristics that trade accuracy for efficiency. The formulation is general and sheds some light on the heuristics used in hsp and Graphplan, and their relation. It exploits the factored (Strips) representation of planning problems, mapping shortest-path problems in state-space into suitably defined shortest-path problems in atom-space. The formulation applies with little variation to sequential and parallel planning, and problems with different action costs. [114] Erik Johan Sandewall. 2000. M. Shanahan, Solving the Frame Problem. Artificial Intelligence, 123(1-2):271–273. DOI: 10.1016/S0004-3702(00)00058-8. [113] Fredrik Heintz. 2000. FCFoo99. In Proceedings of RoboCup-99: Robot Soccer World Cup III (RoboCup), pages 563–566. In series: Lecture Notes in Computer Science #1856. Springer London. ISBN: 3-540-41043-0. Link: http://dl.acm.org/citation.cfm?id=698527 Introduction The emphasis of FCFoo was mainly on building a library for developers of RoboCup teams, designed especially for educational use. After the competition the library was more or less totally rewritten and nally published as part of the Master Thesis of Fredrik Heintz [4]. The agents are built on a layered reactive-deliberative architecture. The four layers describes the agent on dierent levels of abstraction and deliberation. The lowest level is mainly reactive while the others are more deliberate. The teamwork is based on nite automatas and roles. A role is a set of attributes describing some of the behaviour of a player. The decision-making uses decisiontrees to classify the situation and select the appropriate skill to perform. The other two layers are used to calculate the actual command to be sent to the server. The agent architecture and the basic design are inspired by the champions of RoboCup'98, CMUnited [6, 7]. The idea of using decision-trees and role [112] Peter Jonsson, Patrik Haslum and Christer Bckstrm. 2000. Towards efficient universal planning: A randomized approach. Artificial Intelligence, 117(1):1–29. Elsevier. DOI: 10.1016/S0004-3702(99)00103-4. One of the most widespread approaches to reactive planning is Schoppers' universal plans. We propose a stricter definition of universal plans which guarantees a weak notion of soundness, not present in the original definition, and isolate three different types of completeness that capture different behaviors exhibited by universal plans. We show that universal plans which run in polynomial time and are of polynomial size cannot satisfy even the weakest type of completeness unless the polynomial hierarchy collapses. By relaxing either the polynomial time or the polynomial space requirement, the construction of universal plans satisfying the strongest type of completeness becomes trivial. As an alternative approach, we study randomized universal planning. By considering a randomized version of completeness and a restricted (but nontrivial) class of problems, we show that there exists randomized universal plans running in polynomial time and using polynomial space which are sound and complete for the restricted class of problems. We also report experimental results on this approach to planning, showing that the performance of a randomized planner is not easily compared to that of a deterministic planner. [111] Patrick Doherty and Jonas Kvarnstrm. 2000. TALplanner: A temporal logic based forward chaining planner. Annals of Mathematics and Artificial Intelligence, 30(1-4):119–169. Springer. DOI: 10.1023/A:1016619613658. We present TALplanner, a forward-chaining planner based on the use of domain-dependent search control knowledge represented as formulas in the Temporal Action Logic (TAL). TAL is a narrative based linear metric time logic used for reasoning about action and change in incompletely specified dynamic environments. TAL is used as the formal semantic basis for TALplanner, where a TAL goal narrative with control formulas is input to TALplanner which then generates a TAL narrative that entails the goal and control formulas. The sequential version of TALplanner is presented. The expressivity of plan operators is then extended to deal with an interesting class of resource types. An algorithm for generating concurrent plans, where operators have varying durations and internal state, is also presented. All versions of TALplanner have been implemented. The potential of these techniques is demonstrated by applying TALplanner to a number of standard planning benchmarks in the literature. [110] Patrick Doherty, Witold Lukaszewicz and E. Madalinska-Bugaj. 2000. The PMA and relativizing minimal change for action update. Fundamenta Informaticae, 44(1-2):95–131. IOS Press. Recently, a great deal of progress has been made using nonmonotonic temporal logics to formalize reasoning about action and change. In particular, much focus has been placed on the proper representation of non-deterministic actions and the indirect effects of actions. For the latter the use of causal or fluent dependency rule approaches has been dominant. Although much recent effort has also been spent applying the belief revision/update (BR/U) approach to the action and change domain, there has been less progress in dealing with nondeterministic update and indirect effects represented as integrity constraints. We demonstrate that much is to be gained by cross-fertilization between the two paradigms and we show this in the following manner. We first propose a generalization of the PMA, called the modified MPMA which uses intuitions from the TL paradigm to permit representation of nondeterministic update and the use of integrity constraints interpreted as causal or fluent dependency rules. We provide several syntactic characterizations of MPMA, one of which is in terms of a simple temporal logic and provide a representation theorem showing equivalence between the two. In constructing the MPMA, we discovered a syntactic anomaly which we call the redundant atom anomaly that many TL approaches suffer from. We provide a method for avoiding the problem which is equally applicable across paradigms. We also describe a syntactic characterization of MPMA in terms of Dijkstra semantics. We set up a framework for future generalization of the BR/U approach and conclude with a formal comparison of related approaches. [109] Jonas Kvarnstrm and Patrick Doherty. 2000. Tackling the qualification problem using fluent dependency constraints. Computational intelligence, 16(2):169–209. Blackwell Publishing. DOI: 10.1111/0824-7935.00111. In the area of formal reasoning about action and change, one of the fundamental representation problems is providing concise modular and incremental specifications of action types and world models, where instantiations of action types are invoked by agents such as mobile robots. Provided the preconditions to the action are true, their invocation results in changes to the world model concomitant with the goal-directed behavior of the agent. One particularly difficult class of related problems, collectively called the qualification problem, deals with the need to find a concise incremental and modular means of characterizing the plethora of exceptional conditions that might qualify an action, but generally do not, without having to explicitly enumerate them in the preconditions to an action. We show how fluent dependency constraints together with the use of durational fluents can be used to deal with problems associated with action qualification using a temporal logic for action and change called TAL-Q. We demonstrate the approach using action scenarios that combine solutions to the frame, ramification, and qualification problems in the context of actions with duration, concurrent actions, nondeterministic actions, and the use of both Boolean and non-Boolean fluents. The circumscription policy used for the combined problems is reducible to the first-order case. [108] Jonas Kvarnstrm, Patrick Doherty and Patrik Haslum. 2000. Extending TALplanner with concurrency and resources. In Proceedings of the 14th European Conference on Artificial Intelligence (ECAI), pages 501–505. In series: Frontiers in Artificial Intelligence and Applications #54. IOS Press. ISBN: 4274903885, 1586030132. Link: http://swepub.kb.se/bib/swepub:oai:DiVA.... We present TALplanner, a forward-chaining planner based on the use of domain-dependent search control knowledge represented as temporal formulas in the Temporal Action Logic (TAL). TAL is a narrative based linear metric time logic used for reasoning about action and change in incompletely specified dynamic environments. TAL is used as the formal semantic basis for TALplanner, where a TAL goal narrative with control formulas is input to TALplanner which then generates a TAL narrative that entails the goal formula. We extend the sequential version of TALplanner, which has previously shown impressive performance on standard benchmarks, in two respects: 1) TALplanner is extended to generate concurrent plans, where operators have varied durations and internal state; and 2) the expressiveness of plan operators is extended for dealing with several different types of resources. The extensions to the planner have been implemented and concurrent planning with resources is demonstrated using an extended logistics benchmark. [107] Patrick Doherty, Witold Lukaszewicz and Andrzej Szalas. 2000. Efficient reasoning using the local closed-world assumption. In Proceedings of the 9th International Conference on Artificial Intelligence: Methodology, Systems and Applications (AIMSA), pages 49–58. In series: Lecture Notes in Computer Science #1904. Springer Berlin/Heidelberg. ISBN: 978-3-540-41044-7, 978-3-540-45331-4. DOI: 10.1007/3-540-45331-8_5. We present a sound and complete, tractable inference method for reasoning with localized closed world assumptions (LCWA’s) which can be used in applications where a reasoning or planning agent can not assume complete information about planning or reasoning states. This Open World Assumption is generally necessary in most realistic robotics applications. The inference procedure subsumes that described in Etzioni et al [9], and others. In addition, it provides a great deal more expressivity, permitting limited use of negation and disjunction in the representation of LCWA’s, while still retaining tractability. The ap- proach is based on the use of circumscription and quantifier elimination techniques and inference is viewed as querying a deductive database. Both the preprocessing of the database using circumscription and quan- tifier elimination, and the inference method itself, have polynomial time and space complexity. [106] Patrick Doherty, Gsta Granlund, Krzysztof Kuchcinski, Erik Johan Sandewall, Klas Nordberg, Erik Skarman and Johan Wiklund. 2000. The WITAS unmanned aerial vehicle project. In Werner Horn, editor, Proceedings of the 14th European Conference on Artificial Intelligence (ECAI), pages 747–755. IOS Press. ISBN: 1-58603-013-2, 4-274-90388-5. Link: http://www2.cvl.isy.liu.se/ScOut/Publica... The purpose of this paper is to provide a broad overview of the WITAS Unmanned Aerial Vehicle Project. The WITAS UAV project is an ambitious, long-term basic research project with the goal of developing technologies and functionalities necessary for the successful deployment of a fully autonomous UAV operating over diverse geographical terrain containing road and traffic networks. Theproject is multi-disciplinary in nature, requiring many different research competences, and covering a broad spectrum of basic research issues, many of which relate to current topics in artificial intelligence. A number of topics considered are knowledge representation issues, active vision systems and their integration with deliberative/reactive architectures, helicopter modeling and control, ground operator dialogue systems, actual physical platforms, and a number of simulation techniques. [105] Gsta Granlund, Klas Nordberg, Johan Wiklund, Patrick Doherty, Erik Skarman and Erik Sandewall. 2000. WITAS: An Intelligent Autonomous Aircraft Using Active Vision. In Proceedings of the UAV 2000 International Technical Conference and Exhibition (UAV). Euro UVS. fulltext:preprint: http://liu.diva-portal.org/smash/get/div... The WITAS Unmanned Aerial Vehicle Project is a long term basic research project located at Linköping University (LIU), Sweden. The project is multi-disciplinary in nature and involves cooperation with different departments at LIU, and a number of other universities in Europe, the USA, and South America. In addition to academic cooperation, the project involves collaboration with a number of private companies supplying products and expertise related to simulation tools and models, and the hardware and sensory platforms used for actual flight experimentation with the UAV. Currently, the project is in its second phase with an intended duration from 2000-2003.This paper will begin with a brief overview of the project, but will focus primarily on the computer vision related issues associated with interpreting the operational environment which consists of traffic and road networks and vehicular patterns associated with these networks. 1999 [104] Andreas Nonnengart, Hans-Jrgen Ohlbach and Andrzej Szalas. 1999. Elimination of Predicate Quantifiers. In Logic, Language and Reasoning. Essays in Honor of Dov Gabbay, Part I, pages 159–181. Kluwer Academic Publishers. [103] Lars Karlsson and Joakim Gustafsson. 1999. Reasoning about Concurrent Interaction. Journal of logic and computation (Print), 9(5):623–650. Oxford University Press. DOI: 10.1093/logcom/9.5.623. In this paper we present TAL-C, a logic of action and change for worlds with action concurrency. TAL-C has a first-order semantics and proof theory. It builds on an existing logic TAL, which includes the use of dependency laws for dealing with ramification. It is demonstrated how TAL-C can represent a number of phenomena related to action concurrency: action duration, how the effects of one action interferes with or enables another action, synergistic effects of concurrent actions, conflicting and cumulative effect interactions, and resource conflicts. A central idea is that actions are not described as having effects that directly alter the world state. Instead, actions produce influences, and the way these influences alter the world state are described in specialized influence laws. Finally, we address how TAL-C narratives can be written to support modularity. [102] Patrik Haslum. 1999. Model Checking by Random Walk. In Proceedings of the ECSEL Workshop (CCSSE). While model checking algorithms are in theory efficient, they are in practice hampered by the explosive growth of system models. We show that for certain specifications the model cheking problem reduces to a question of reachability in the system state transition graph, and apply a simple, randomized algorithm to this problem. [101] Fredrik Tjrnstrm, Mattias Duppils, Patrik Haslum, David Byers, Gundars Kulups and Dan Lawesson. 1999. ENSYM-Project Oriented Studies of spring 98 - team 1. Technical Report. In series: LiTH-ISY-R #2094. Linkping University Electronic Press. 14 pages. The report is description of the ENSYM Project Oriented Studies(POS) of spring 1998. The project goal was to control a toy cararound a not beforehand given track as fast as possible. [100] Thord Andersson, Silvia Coradeschi and Alessandro Saffiotti. 1999. Fuzzy matching of visual cues in an unmanned airborne vehicle. Technical Report. Linkping University, Department of Electrical Engineering. Computer vision systems used in autonomous mobile vehicles are typically linked to higher-level deliberation processes. One important aspect of this link is how to connect, or anchor, the symbols used at the higher level to the objects in the vision system that these symbols refer to. Anchoring is complicated by the fact that the vision data are inherently affected by uncertainty. We propose an anchoring technique that uses fuzzy sets to represent the uncertainty in the perceptual data. We show examples where this technique allows a deliberative system to reason about the objects (cars) detected by a vision system embarked in an unmanned helicopter, in the framework of the Witas project. [99] Thomas Drakengren and Marcus Bjreland. 1999. Reasoning about action in polynomial time. Artificial Intelligence, 115(1):1–24. Elsevier. DOI: 10.1016/S0004-3702(99)00065-X. Although many formalisms for reasoning about action exist, surprisingly few approaches have taken computational complexity into consideration. The contributions of this article are the following: a temporal logic with a restriction for which deciding satisfiability is tractable, a tractable extension for reasoning about action, and NP-completeness results for the unrestricted problems. Many interesting reasoning problems can be modelled, involving nondeterminism, concurrency and memory of actions. The reasoning process is proved to be sound and complete. (C) 1999 Published by Elsevier Science B.V. All rights reserved. [98] Paul Scerri, Silvia Coradeschi and Anders Trne. 1999. A user oriented system for developing behavior based agents. In Minoru Asada and Hiroaki Kitano, editors, RoboCup-98: Robot Soccer World Cup II, pages 173–186. In series: Lecture Notes in Computer Science #1604. Springer Berlin/Heidelberg. ISBN: 978-3-540-66320-1, e-978-3-540-48422-6, 3-540-66320-7. DOI: 10.1007/3-540-48422-1_14. Developing agents for simulation environments is usually the responsibility of computer experts. However, as domain experts have superior knowledge of the intended agent behavior, it is desirable to have domain experts directly specifying behavior. In this paper we describe a system which allows non-computer experts to specify the behavior of agents for the RoboCup domain. An agent designer is presented with a Graphical User Interface with which he can specify behaviors and activation conditions for behaviors in a layered behavior-based system. To support the testing and debugging process we are also developing interfaces that show, in real-time, the world from the agents perspective and the state of its reasoning process. [97] Silvia Coradeschi and Jasec Malec. 1999. How to make a challenging AI course enjoyable using the RoboCup soccer simulation system. In Minoru Asada and Hiroaki Kitano, editors, RoboCup-98: Robot Soccer World Cup II, pages 120–124. In series: Lecture Notes in Computer Science #1604. Springer Berlin/Heidelberg. ISBN: 3-540-66320-7. DOI: 10.1007/3-540-48422-1_9. In this paper we present an AI programming organised around the RoboCup soccer simulation system. The course participants create a number of software agents that form a team, and participate in a tournament at the end of the course. The use of a challenging and interesting task, and the incentive of having a tournament has made the course quite successful, both in term of enthusiasm of the students and of knowledge acquired. In the paper we describe the structure of the course, discuss in what respect we think the course has met its aim, and the opinions of the students about the course. [96] Marcus Bjreland and Peter Jonsson. 1999. Exploiting bipartiteness to identify yet another tractable subclass of CSP. In Proceedings of the 5th International Conference on Principles and Practice of Constraint Programming (CP), pages 118–128. In series: Lecture Notes in Computer Science #1713. Springer. DOI: 10.1007/978-3-540-48085-3_9. The class of constraint satisfaction problems (CSPs) over finite domains has been shown to be NP-complete, but many tractable subclasses have been identified in the literature. In this paper we are interested in restrictions on the types of constraint relations in CSP instances. By a result of Jeavons et al. we know that a key to the complexity of classes arising from such restrictions is the closure properties of the sets of relations. It has been shown that sets of relations that are closed under constant, majority, affine, or associative, commutative, and idempotent (ACI) functions yield tractable subclasses of CSP. However, it has been unknown whether other closure properties may generate tractable subclasses. In this paper we introduce a class of tractable (in fact, SL-complete) CSPs based on bipartite graphs. We show that there are members of this class that are not closed under constant, majority, affine, or ACI functions, and that it, therefore, is incomparable with previously identified classes. [95] Patrik Haslum and Peter Jonsson. 1999. Some results on the complexity of planning with incomplete information. In Proceedings of the 5th European Conference on Planning (ECP), pages 308–318. In series: Lecture Notes in Computer Science #1809. Springer. DOI: 10.1007/10720246_24. Planning with incomplete information may mean a number of different things, that certain facts of the initial state are not known, that operators can have random or nondeterministic effects, or that the plans created contain sensing operations and are branching. Study of the complexity of incomplete information planning has so far been concentrated on probabilistic domains, where a number of results have been found. We examine the complexity of planning in nondeterministic propositional domains. This differs from domains involving randomness, which has been well studied, in that for a nondeterministic choice, not even a probability distribution over the possible outcomes is known. The main result of this paper is that the non-branching plan existence problem in unobservable domains with an expressive operator formalism is EXPSPACE-complete. We also discuss several restrictions, which bring the complexity of the problem down to PSPACF-complete, and extensions to the fully and partially observable cases. [94] Patrick Doherty, Jaroslaw Kachniarz and Andrzej Szalas. 1999. Meta-queries on deductive databases. Fundamenta Informaticae, 40(1):17–30. IOS Press. DOI: 10.3233/FI-1999-40102. We introduce the notion of a meta-query on relational databases and a technique which can be used to represent and solve a number of interesting problems from the area of knowledge representation using logic. The technique is based on the use of quantifier elimination and may also be used to query relational databases using a declarative query language called SHQL (Semi-Horn Query Language), introduced in [6]. SHQL is a fragment of classical first-order predicate logic and allows us to define a query without supplying its explicit definition. All SHQL queries to the database can be processed in polynomial time (both on the size of the input query and the size of the database). We demonstrate the use of the technique in problem solving by structuring logical puzzles from the Knights and Knaves domain as SHQL meta-queries on relational databases. We also provide additional examples demonstrating the flexibility of the technique. We conclude with a description of a newly developed software tool, The Logic Engineer, which aids in the description of algorithms using transformation and reduction techniques such as those applied in the meta-querying approach. [93] Patrick Doherty, Witold Lukaszewicz and Andrzej Szalas. 1999. Declarative PTIME queries for relational databases using quantifier elimination. Journal of logic and computation (Print), 9(5):737–758. Oxford University Press. DOI: 10.1093/logcom/9.5.737. In this paper, we consider the problem of expressing and computing queries on relational deductive databases in a purely declarative query language, called SHQL (Semi-Horn Query Language). Assuming the relational databases in question are ordered, we show that all SHQL queries are computable in PTIME (polynomial time) and the whole class of PTIME queries is expressible in SHQL. Although similar results have been proven for fixpoint languages and extensions to datalog, the claim is that SHQL has the advantage of being purely declarative, where the negation operator is interpreted as classical negation, mixed quantifiers may be used and a query is simply a restricted first-order theory not limited by the rule-based syntactic restrictions associated with logic programs in general. We describe the PTIME algorithm used to compute queries in SHQL which is based in part on quantifier elimination techniques and also consider extending the method to incomplete relational databases using intuitions related to circumscription techniques. [92] Patrick Doherty, Witold Lukaszewicz and E. Madalinska-Bugaj. 1999. Computing MPMA updates using dijkstra's semantics. In 12th International Symposium on Methodologies for Intelligent Systems,1999. Springer. [91] Patrick Doherty and Jonas Kvarnstrm. 1999. TALplanner: An empirical investigation of a temporal logic-based forward chaining planner. In Clare Dixon, Michael Fisher, editors, 6th International Workshop on Temporal Representation and Reasoning (TIME-99). IEEE Computer Society. ISBN: 0-7695-0173-7. We present a new forward chaining planner, TALplanner, based on ideas developed by Bacchus and Kabanza, where domain-dependent search control knowledge represented as temporal formulas is used to effectively control forward chaining. Instead of using a linear modal tense logic as with Bacchus and Kabanza, we use TAL, a narrative-based linear temporal logic used for reasoning about action and change in incompletely specified dynamic environments. Two versions of TALplanner are considered, TALplan/modal which is based on the use of emulated modal formulas and a progression algorithm, and TALplan/non-modal which uses neither modal formulas nor a progression algorithm. For both versions of TALplanner and for all tested domains, TALplanner is shown to be considerably faster and requires less memory. The TAL versions also permit the representation of durative actions with internal state. [90] John-Jules Meyer and Patrick Doherty. 1999. Preferential action semantics (preliminary report). In Formal Models of Agents: ESPRIT Project Modelage Final Workshop Selected Papers, pages 187–201. In series: Lecture Notes in Artificial Intelligence #1760. Springer. ISBN: 3-540-67027-0. DOI: 10.1007/3-540-46581-2_13. Note: Preliminary report In this paper, we propose a new way of considering reasoning about action and change. Rather than placing a preferential structure onto the models of logical theories, we place such a structure directly on the semantics of the actions involved. In this way, we obtain a preferential semantics of actions by means of which we can not only deal with several of the traditional problems in this area such as the frame and ramification problems, but can generalize these solutions to a context which includes both nondeterministic and concurrent actions. In fact, the net result is an integration of semantical and verificational techniques from the paradigm of imperative and concurrent programs in particular, as known from traditional programming, with the AI perspective. In this paper, the main focus is on semantical (i.e. model theoretical) issues rather than providing a logical calculus, which would be the next step in the endeavor. [89] Silvia Coradeschi. 1999. Anchoring symbols to sensory data. PhD Thesis. In series: Linkping Studies in Science and Technology. Dissertations #611. Linkpings universitet. 136 pages. ISBN: 91-7219-623-8. Intelligent agents embedded in physical environments need the ability to connect, or anchor, the symbols used to perform abstract reasoning to the physical entities which these symbols refer to. Anchoring must deal with indexical and objective references, definite and indefinite identifiers, and a temporary impossibility to perceive physical entities. Furthermore it needs to rely on sensor data which is inherently affected by uncertainty, and to deal with ambiguities. In this thesis, we outline the concept of anchoring and its functionalities. Moreover we define the general structure for an anchoring module and we present an implementation of the anchoring functionalities in two different domains: an autonomous airborne vehicle for traffic surveillance and a mobile ground vehicle performing navigation. [88] Silvia Coradeschi, Lars Karlsson and Klas Nordberg. 1999. Integration of vision and decision-making in an autonomous airborne vehicle for traffic surveillance. In Proceedings of the International Conference on Vision Systems '99: Grand Canary. In this paper we present a system which integrates computer vision and decision-making in an autonomous airborne vehicle that performs traffic surveillance tasks. The main factors that make the integration of vision and decision-making a challenging problem are: the qualitatively different kind of information at the decision-making and vision levels, the need for integration of dynamically acquired information with a priori knowledge, e.g. GIS information, and the need of close feedback and guidance of the vision module by the decision-making module. Given the complex interaction between the vision module and the decision-making module we propose the adoption of an intermediate structure, called Scene Information Manager, and describe its structure and functionalities. 1998 [87] Mns Engman, Tommy Persson and Peter Fritzson. 1998. Generating Parallel Graphics Code from Symbolic-algebra Specifications. In . [86] Leonard Bolc, Krzysztof Dziewicki, Piotr Rychlik and Andrzej Szalas. 1998. Wnioskowanie w logikach nieklasycznych: Automatyzacja wnioskowania. Book. Academic Pub. PLJ (Akademicka Oficyna Wydawnicza PLJ). 159 pages. ISBN: 83-7101-403-1, 978-83-7101-403-1. Find book in another country/Hitta boken i ett annat land: http://www.worldcat.org/search?q=83-7101... [85] Andreas Nonnengart and Andrzej Szalas. 1998. A Fixpoint Approach to Second-Order Quantifier Elimination with Applications to Correspondence Theory. In Ewa Orlowska, editor, Logic at work: essays dedicated to the memory of Helena Rasiowa, pages 307–328. In series: Studies in Fuzziness and Soft Computing #24. Physica Verlag. ISBN: 3-7908-1164-5. Find book at a Swedish library/Hitta boken i ett svenskt bibliotek: http://libris.kb.se/hitlist?d=libris&q=3... Find book in another country/Hitta boken i ett annat land: http://www.worldcat.org/search?q=3-7908-... [84] Marcus Bjreland. 1998. Two Aspects of Automating Logics of Action and Change: Regression and Tractability. Licentiate Thesis. In series: Linkping Studies in Science and Technology. Thesis #674. Linkpings universitet. 83 pages. ISBN: 91-7219-173-2. Note: Thesis No 674. LiU-Tek-Lic 1998:09 The autonomy of an artificial agent (e.g. a robot) will certainly depend on its ability to perform \"intelligent\" tasks, such as learning, planning, and reasoning about its own actions and their effects on the enviroment, for example predicting the consequences of its own behaviour. To be able to perform these (and many more) tasks, the agent will have to represent its knowledge about the world.The research field \"Logics of Action Change\" is concerned with the modelling of agents and dynamical, changing environments with logics.In this thesis we study two aspects of automation of logics of action and change. The first aspect, regression, is used to \"reason backwards\", i.e. to start with the last time point in a description of a course of events, and moving backwards through these events, taking the effects of all actions into consideration. We discuss the consequences for regression of introducing nondeterministic actions, and provide the logic PMON with pre- and postdiction procedures. We employ the classical computer science tool, the weakest liberal precondition operator (wlp) for this, and show that logical entailment of PMON is equivalent to wlp computations.The second aspect is computational complexity of logics of action and change, which has virtually been neglected by the research community. We present a new and expressive logic, capable of expressing continuous time, nondeterministic actions, concurrency, and memory of actions. We show that satisfiability of a theory in this logic is NP-complete. Furthermore, we identify a tractable subset of the logic, and provide a sound, complete, and polynomial algorithm for satisfiability of the subset. [83] Patrick Doherty and Joakim Gustafsson. 1998. Delayed effects of actions = direct effects + causal rules. Technical Report. In series: Linkping Electronic Articles in Computer and Information Science #98-001. Linkping University Electronic Press. Link: http://www.ep.liu.se/ea/cis/1998/001/ We propose an approach to modeling delayed effects of actions which is based on the use of causal constraints and their interaction with the direct effects of actions. The approach extends previous work with a causal approach used to deal with the ramification problem. We show the similarity between solutions to the modeling of indirect effects and delayed effects of actions by example. The base logic PMON+ is a temporal logic for reasoning about action and change and uses circumscription. It is shown that the extension for delayed effects of actions retains the first-order reducibility property shown previously for successfully dealing with the frame and ramification problems for a large class of action scenarios. We also consider the “causal qualification” problem, \"natural death\" of fluents and causal lag, each of which is closely related to the use of delayed effects. [82] Patrick Doherty, Joakim Gustafsson, Lars Karlsson and Jonas Kvarnstrm. 1998. (TAL) temporal action logics: Language specification and tutorial. Electronic Transactions on Artifical Intelligence, 2(3-4):273–306. Link: http://www.ep.liu.se/ej/etai/1998/009/ The purpose of this article is to provide a uniform, lightweight language specication and tutorial for a class of temporal logics for reasoning about action and change that has been developed by our group during the period 1994-1998. The class of logics are collected under the name TAL, an acronym for Temporal Action Logics. TAL has its origins and inspiration in the work with Features and Fluents (FF) by Sandewall, but has diverged from the methodology and approach through the years. We first discuss distinctions and compatibility with FF, move on to the lightweight language specication, and then present a tutorial in terms of an excursion through the different parts of a relatively complex narrative defined using TAL. We conclude with an annotated list of published work from our group. The article tries to strike a reasonable balance between detail and readability, making a number of simplications regarding narrative syntax and translation to a base logical language. Full details are available in numerous technical reports and articles which are listed in the final section of this article. [81] Patrick Doherty, Witold Lukaszewicz and Andrzej Szalas. 1998. General domain circumscription and its effective reductions. Fundamenta Informaticae, 36(1):23–55. IOS Press. DOI: 10.3233/FI-1998-3612. We first define general domain circumscription (GDC) and provide it with a semantics. GDC subsumes existing domain circumscription proposals in that it allows varying of arbitrary predicates, functions, or constants, to maximize the minimization of the domain of a theory. We then show that for the class of semi-universal theories without function symbols, that the domain circumscription of such theories can be constructively reduced to logically equivalent first-order theories by using an extension of the DLS algorithm, previously proposed by the authors for reducing second-order formulas. We also show that for a certain class of domain circumscribed theories, that any arbitrary second-order circumscription policy applied to these theories is guaranteed to be reducible to a logically equivalent first-order theory. In the case of semi-universal theories with functions and arbitrary theories which are not separated, we provide additional results, which although not guaranteed to provide reductions in all cases, do provide reductions in some cases. These results are based on the use of fixpoint reductions. [80] Lars Karlsson, Joakim Gustafsson and Patrick Doherty. 1998. Delayed effects of actions. In Proceedings of the 13th European Conference on Artificial Intelligence (ECAI), pages 542–546. John Wiley & Sons. ISBN: 978-0471984313. [79] Patrick Doherty, Witold Lukaszewicz and Ewa Madalinska-Bugaj. 1998. The PMA and relativizing change for action update. In Proceedings of the 6th International Conference on Principles of Knowledge Representation and Reasoning (KR), pages 258–269. Morgan Kaufmann Publishers. Using intuitions from the temporal reasoning community, we provide a generalization of the PMA, called the modified PMA (MPMA), which permits the representation of disjunctive updates and the use of integrity constraints interpreted as causal constraints. In addition, we provide a number of syntactic characterizations of the MPMA, one of which is constructed by mapping an MPMA update of a knowledge base into a temporal narrative in a simple temporal logic (STL). The resulting representation theorem provides a basis for computing entailments of the MPMA and could serve as a basis for further generalization of the belief update approach for reasoning about action and change. [78] Patrick Doherty and Jonas Kvarnstrm. 1998. Tackling the qualification problem using fluent dependency constraints. In Lina Khatib, Robert Morris, editors, Proceedings of the 5th International Workshop on Temporal Representation and Reasoning (TIME-98). IEEE Computer Society. ISBN: 0-8186-8473-9. Note: Preliminary report The use of causal rules or fluent dependency constraints has proven to provide a versatile means of dealing with the ramification problem. In this paper we show how fluent dependency constraints together with the use of durational fluents can be used to deal with problems associated with action qualification. We provide both a \emph{weak} and \emph{strong} form of qualification and demonstrate the approach using an action scenario which combines solutions to the frame, ramification and qualification problems in the context of actions with duration, concurrent actions, non-deterministic actions and the use of both boolean and non-boolean fluents. The circumscription policy used for the combined problems is reducible to the 1st-order case. In addition, we demonstrate the use of a research tool VITAL, for querying and visualizing action scenarios. 1997 [77] Dag Fritzson, Peter Fritzson, Patrik Nordling and Tommy Persson. 1997. Rolling Bearing Simulation on MIMD Computers. The international journal of high performance computing applications, 11(4):299–313. Sage Publications. DOI: 10.1177/109434209701100404. Fulltext: http://dx.doi.org/10.1177/10943420970110... Rolling bearing simulations are very computationally in tensive. Serial simulations may take weeks to execute, and there is a need to use the potential of parallel comput ing. The specific structure of the rolling bearing problem is used to develop suitable scheduling strategies. The authors discuss the system of stiff ordinary differential equations arising from a bearing model and show how to numerically solve these ordinary differential equations on parallel computers. Benchmarking results are presented for two test cases on three platforms. [76] Thomas Drakengren and Marcus Bjreland. 1997. Reasoning about Action in Polynomial Time. In Proceedings of the 15th International Joint Conference on Artificial Intelligence (IJCAI). [75] Marcus Bjreland and Lars Karlsson. 1997. Reasoning by Regression: Pre- and Postdiction Procedures for Logics of Action and Change with Nondeterminism. In Proceedings of the 15th International Joint Conference on Artficial Intelligence (IJCAI). [74] Erik Sandewall. 1997. Strategies and policies of Linkping University Electronic Press. Technical Report. In series: Linkping Electronic Articles on Academic Policies and Trends #1 Vol. 1. Linkping University Electronic Press. 15 pages. Linköping University has recently created a separate entity, called Linköping University Electronic Press, for the unrefereed electronic publication of research articles and other university-related materials over the Internet. The present article presents the background for why the E-Press was created and the strategies which have been chosen for its operation at least during its initial period. The article identifies three key problems in the context of this strategy:
• The purely formal problems concerning what counts as a publication;
• The persistence problem of making sure that an electronically published article does not change over time;
• The reception problems concerning how fellow researchersand the academic community regard electronically published articles.
We describe how the formal problems and the persistence problems have been addressed in the E-Press initiative. With respect to the reception problems, we argue that scientific journals and journal-like conferences presently perform four distinct functions, and that these functions can be performed better if they are “unbundled” and addressed by other means. The four functions are:
• Publication in the narrow sense - making the article publicly available;
• Scientific quality control through reviewing;
• Selection of relevant articles for the benefit of the researcher-reader;
• Promotion of the scientific results of the author.
The Electronic Press focusses on the first one of these four functions. We discuss how the other three functions can be separated and performed by other means than through a conventional journal or quality conference proceedings.
[73] Erik Sandewall. 1997. A Neo-Classical Structure for Scientific Publication and Reviewing. Technical Report. In series: Linkping Electronic Articles on Academic Policies and Trends #1 Vol, 2. Linkping University Electronic Press. 28 pages. I propose a neo-classical structure for publishing and reviewing of scientific works. This proposal has the following characteristic components:
• Electronic “preprint archives” and other similar mechanisms where research articles are made publicly available without prior formal review are considered as true and full-fledged publication of research from the point of view of priority of results.
• Large parts of the reviewing process is done publicly and in the form of published review letters and other contributions to the scientific debate, rather than through anonymous and confidential review statements which dominate today. There is a switch from anonymous “pass-fail” reviewing towards open reviewing where the identity and the comments of the reviewers are made public.
• Since open reviewing happens after publication, rather than before, there is a second step where articles are promoted to “recommended” or “certified” status through the decision of a review committee. The requirements for certification are set at least as high as for the formally published journal articles of today, so that it counts like journal publication in a CV.
• Several techniques are foreseen for facilitating the selection process of the individual reader as well as for improving communication as such between researchers.
• One should accept that there are good reasons why there may be several articles (from the same author) presenting the same result. This suggests the introduction of a formal concept of a “result” which is represented by several publications, and to allow citations to refer to results rather than to some specific publication of the result.
I refer to this system as neo-classical because it assumes that peer review is done openly and after an article has been published. It is of course only proposed as a complement which can easily co-exist with the modern system, allowing each author to choose which of the two systems he or she wishes to use for a particular article.
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2017-10-23 09:53:24
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http://tex.stackexchange.com/questions/136907/recursive-drawing-command-flow
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# Recursive drawing, command flow
I am trying to recursively draw Ck x Ck, where Ck is the k-th iteration of a Cantor set. I have a command which recursively calls itself four times. If I pass N as parameter #6, the output should be 4N little squares. But it only works for N = 1, 2. If I do anything higher, I only get 4 squares, spaced out in the four corners. They are the right size, but there aren't enough of them.
Apparently, the problem has something do with \pgfmathtruncatemacro\C{#6 - 1}. As a test I inserted \draw (0,0) circle (#6); right before this line, and then right after this line, and the output was NOT always the same. It seems that \pgfmathtruncatemacro\C{#6 - 1} somehow changes the value of #6 (in the SAME level of recursion), but I don't see why.
\usepackage{tikz, pgf, ifthen}
\newcommand\cantorsquare[6]{ %x y x y coordinates, dissection coordinates, nesting
%the coordinates are listed in the same order as coordinates for a rectangle
\ifthenelse{#6 = 0} %base case
{
\fill (#1, #2) rectangle (#3, #4);
}
{
{
%find the coordinates for the first smaller square
\pgfmathsetmacro\A{#1 + (1 - #5) * (#3 - #1) / 2}
\pgfmathsetmacro\B{#2 + (1 - #5) * (#4 - #2) / 2}
\pgfmathtruncatemacro\C{#6 - 1}
\cantorsquare{#1}{#2}{\A}{\B}{#5}{\C}
}
{
\pgfmathsetmacro\A{#1 + (1 - #5) * (#3 - #1) / 2}
\pgfmathsetmacro\B{#4 - (1 - #5) * (#4 - #2) / 2}
\pgfmathtruncatemacro\C{#6 - 1}
\cantorsquare{#1}{\B}{\A}{#4}{#5}{\C}
}
{
\pgfmathsetmacro\A{#3 - (1 - #5) * (#3 - #1) / 2}
\pgfmathsetmacro\B{#2 + (1 - #5) * (#4 - #2) / 2}
\pgfmathtruncatemacro\C{#6 - 1}
\cantorsquare{\A}{#2}{#3}{\B}{#5}{\C}
}
{
\pgfmathsetmacro\A{#3 - (1 - #5) * (#3 - #1) / 2}
\pgfmathsetmacro\B{#4 - (1 - #5) * (#4 - #2) / 2}
\pgfmathtruncatemacro\C{#6 - 1}
\cantorsquare{\A}{\B}{#3}{#4}{#5}{\C}
}
}
}
\begin{document}
\begin{tikzpicture} \cantorsquare{0}{0}{5}{5}{0.3}{3} \end{tikzpicture}
\end{document}
-
If for Cantor set you mean a Cantor switching fabric, then I believe you might have a look to the sa-tikz package (where sa stands for switching architectures). Cantor Networks indeed are are just m parallel Benes Networks, and sa-tikz exploits an embedded algorithm to deal with such recursion (more details in the appendix of the documentation). Indeed it's quite easy to draw the modules, but having automatically the interconnections it's a bit complicated and notice that the algorithm works for any dimension of the network. – Claudio Fiandrino Oct 8 '13 at 6:22
@ClaudioFiandrino Having looked at the output, I suspect David means this: en.wikipedia.org/wiki/Cantor_set – Loop Space Oct 8 '13 at 7:54
@AndrewStacey: ops... I might have given a check first, but anyway: perhaps I'll remove my answer later, but it was useful as now I have in mind how to extend the library to draw Cantor Networks ;) – Claudio Fiandrino Oct 8 '13 at 7:59
I agree with Michael's analysis: that it is a problem of expansion. When you pass \C as the sixth element then #6 gets replaced in the macro body by \C so if \C changes then so does the ultimate value of #6. In particular, when you do \pgfmathtruncatemacro\C{#6 - 1} then you are redefining #6.
Having said that, I'm not sure where the expansion is going wrong because you've correctly grouped your recursive calls so modifications to \C in one iteration shouldn't affect others. Moreover, when I run your code then I get the answer that I expect to see. So I have a suspicion that this is an issue with an old version of PGF making a global assignment where it should make a local one. What version of PGF are you using?
I find that LaTeX3 has lots of useful stuff that helps sort out these issues of expansion. In particular, it is possible to ensure that the value of a macro is passed, not the macro itself. So here is your code rewritten in LaTeX3. By passing values rather than macros, I can avoid having to group the recursive calls.
\documentclass{article}
%\url{http://tex.stackexchange.com/q/136907/86}
\usepackage{tikz}
\usepackage{xparse}
\ExplSyntaxOn
\cs_new_nopar:Npn \cantor_sq:nnnnnn #1#2#3#4#5#6
{
\int_compare:nTF {#6 = 0}
{
\fill (\fp_to_decimal:n {#1},\fp_to_decimal:n {#2}) rectangle (\fp_to_decimal:n {#3},\fp_to_decimal:n {#4});
}
{
%find the coordinates for the first smaller square
\fp_set:Nn \l_tmpa_fp {#1 + (1 - #5) * (#3 - #1) / 2}
\fp_set:Nn \l_tmpb_fp {#2 + (1 - #5) * (#4 - #2) / 2}
\int_set:Nn \l_tmpa_int {#6 - 1}
\cantor_sq:nnVVnV {#1}{#2} \l_tmpa_fp \l_tmpb_fp {#5} \l_tmpa_int
\fp_set:Nn \l_tmpa_fp {#1 + (1 - #5) * (#3 - #1) / 2}
\fp_set:Nn \l_tmpb_fp {#4 - (1 - #5) * (#4 - #2) / 2}
\int_set:Nn \l_tmpa_int {#6 - 1}
\cantor_sq:nVVnnV {#1} \l_tmpb_fp \l_tmpa_fp {#4}{#5} \l_tmpa_int
\fp_set:Nn \l_tmpa_fp {#3 - (1 - #5) * (#3 - #1) / 2}
\fp_set:Nn \l_tmpb_fp {#2 + (1 - #5) * (#4 - #2) / 2}
\int_set:Nn \l_tmpa_int {#6 - 1}
\cantor_sq:VnnVnV \l_tmpa_fp {#2}{#3} \l_tmpb_fp {#5} \l_tmpa_int
\fp_set:Nn \l_tmpa_fp {#3 - (1 - #5) * (#3 - #1) / 2}
\fp_set:Nn \l_tmpb_fp {#4 - (1 - #5) * (#4 - #2) / 2}
\int_set:Nn \l_tmpa_int {#6 - 1}
\cantor_sq:VVnnnV \l_tmpa_fp \l_tmpb_fp {#3}{#4}{#5} \l_tmpa_int
}
}
\cs_generate_variant:Nn \cantor_sq:nnnnnn {nnVVnV,nVVnnV,VnnVnV,VVnnnV}
\DeclareDocumentCommand \cantorsquare { m m m m m m }
{
\cantor_sq:nnnnnn {#1}{#2}{#3}{#4}{#5}{#6}
}
\ExplSyntaxOff
\begin{document}
\begin{tikzpicture}
\cantorsquare{0}{0}{5}{5}{0.3}{3}
\end{tikzpicture}
\begin{tikzpicture}
\cantorsquare{0}{0}{5}{5}{0.3}{6}
\end{tikzpicture}
\end{document}
That the small rectangles don't look uniform is an artefact of the rendering as can be seen by looking at a larger zoom.
-
EDIT: Added lualatex version below.
As already pointed out, expansion is the issue, and is easily corrected. However, here is a different solution that requires the very latest PGF/TikZ CVS version.
\documentclass[border=0.125cm]{standalone}
\usepackage{tikz}
\usetikzlibrary{math}
\begin{document}
\begin{tikzpicture}
\tikzmath{
function cantorsquare(\x, \y, \s, \f, \d) {
if (\d == 0) then {
{ \fill (\x, \y) rectangle ++(\s, \s); };
} else {
\u1 = \f*\s;
\u2 = (1-\f)*\s;
cantorsquare(\x, \y, \u1, \f, \d-1);
cantorsquare(\x+\u2, \y, \u1, \f, \d-1);
cantorsquare(\x, \y+\u2, \u1, \f, \d-1);
cantorsquare(\x+\u2, \y+\u2, \u1, \f, \d-1);
};
};
\S = 5;
for \d in {0,...,5}{
\x = int(\d/3) * (\S+1);
\y = mod(\d,3) * (\S+1);
{ \draw (\x-0.1, -\y-0.1) rectangle ++(\S+0.2,\S+0.2); };
cantorsquare(\x, -\y, \S, 1/3, \d);
};
}
\end{tikzpicture}
\end{document}
And here is a version using lualatex which does not require the latest CVS, and is much faster.
\documentclass[border=0.125cm]{standalone}
\usepackage{tikz}
\directlua{
function cantorsquare(x, y, s, f, d)
local u1, u2
if d == 0 then
tex.print("\noexpand\\fill (" .. x .. "," .. y .. ") rectangle ++(" .. s .. "," .. s .. ");")
else
u1 = f*s
u2 = (1-f)*s;
cantorsquare(x, y, u1, f, d-1)
cantorsquare(x+u2, y, u1, f, d-1)
cantorsquare(x, y+u2, u1, f, d-1)
cantorsquare(x+u2, y+u2, u1, f, d-1)
end
end
}
\begin{document}
\begin{tikzpicture}
\foreach \d [evaluate={\S=5; \x=int(\d/3)*(\S+1); \y=mod(\d,3)*(\S+1);}] in {0,...,5}{
\draw (\x-0.1, -\y-0.1) rectangle ++(\S+0.2,\S+0.2);
\directlua{cantorsquare(\x, -\y, \S, 1/3, \d)}
}
\end{tikzpicture}
\end{document}
The result is the same as before.
-
I do not know the details of the packages you are using so it is hard for me to be categorical but it seems you are tripped by the fact that macros passed as arguments are not expanded when the call is performed, but only later when the replacement text where they appear is processed. This may break your recursion. To verify this, you may execute your code with \tracingmacros=1.
You can use registers to force expansion, replacing your usage
\cantorsquare{#1}{#2}{\A}{\B}{#5}{\C}
by
\begingroup
\let\cantorsquare=0\relax % Freeze expansion in edef
\count0=\A\relax
\count2=\B\relax
\count4=\C\relax
\toks0={#1}%
\toks2={#2}%
\toks4={#5}%
\edef\next{%
\cantorsquare{\the\toks0}{\the\toks2}{\the\count0}{\the\count2}{\the\toks4}{\the\count4}%
}%
\expandafter
\endgroup
\next
It prepares a “call” to cantorsquare where \A etc. are replaced by their replacement text — assuming these are numbers. You should edit accordingly each of your four calls.
Note that TeX is a very special computer language, because it does not work with functions and the like, rather, it offers you the possibility to write the sequel of the program—this is what macros are for. If you want to write sophisticated programs in TeX, it is much easier to learn about registers, \edef etc.
Does it help?
Edit: As a side note, I definitely recommand you to have a look at METAPOST if you are interested in programatically generating graphics! It is an awesome piece of software—which just as fun to program as TeX is.
-
Thanks! When I simply put the expressions into the command, it gave me a "missing number" error, but writing them as macros removed the error. So I assumed it must actually be evaluating the expressions. What exactly does setting the macro do? – David Jekel Oct 8 '13 at 7:41
Setting the macro does very little: it defines a new word in TeX's voabulary (a new escape sequence) and associate it to the replacement text you provide. If you are not familiar with macros and replacement texts (which are very different from functions in programming languages) you could read the relevant chapter in the TeXbook, experiment with the \tracingmacros=1 setting (see the log file of your job) or learn M4, which is also based on macros and replacement text—but much simpler as TeX. – Michael Grünewald Oct 8 '13 at 10:47
I don’t know the exact specification of this thing but here’s a recursive attempt with append after command (a previous version used path picture but that only works good with rectangular shapes).
## Code
\documentclass[tikz]{standalone}
\usetikzlibrary{calc}
\tikzset{
if/.code n args={3}{% forest.sty
\pgfmathparse{#1}%
\ifnum\pgfmathresult=0 \pgfkeysalso{#3}\else\pgfkeysalso{#2}\fi},
cantorsquare/.style n args={3}{% #1 = current leve, #2 = max level, #3 = factor
if={#1==#2}{cantorsquare end}{cantorsquare go on={#1+1}{#2}{#3}}},
every cantorsquare/.style={shape=rectangle, outer sep=+0pt, ultra thin},
cantorsquare end/.style={every cantorsquare, fill},
cantorsquare go on/.style n args={3}{
every cantorsquare,
append after command={
\pgfextra{\let\myTikzlastnode\tikzlastnode}
let \p{@dim}=($(\myTikzlastnode.north east)-(\myTikzlastnode.south west)$) in
[next nodes/.style={inner sep=+0pt, outer sep=+0pt, minimum width=(#3)*\x{@dim},
minimum height=(#3)*\y{@dim}, cantorsquare={#1}{#2}{#3}}]
node [next nodes, above right] at (\myTikzlastnode.south west) {}
node [next nodes, above left] at (\myTikzlastnode.south east) {}
node [next nodes, below right] at (\myTikzlastnode.north west) {}
node [next nodes, below left] at (\myTikzlastnode.north east) {}}}}
\begin{document}
\foreach \lev in {1, ..., 5, 4, 3, 2}{
\begin{tikzpicture}
\node[cantorsquare/.expanded={1}{\lev}{.3333}, minimum size=2cm] {};
\end{tikzpicture}}
\foreach \lev in {1, ..., 5, 4, 3, 2}{
\begin{tikzpicture}[every cantorsquare/.append style={shape=circle},
every cantorsquare/.append style=draw]
\node[cantorsquare/.expanded={1}{\lev}{.3333}, minimum size=2cm] {};
\end{tikzpicture}}
\end{document}
-
|
2014-11-21 16:52:23
|
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|
http://photonics-blog.engr.uga.edu/?page_id=583
|
# Midterm Questions
Questions? Post them here.
## 2 thoughts on “Midterm Questions”
1. Minor mistake in Question D-1:
The average beam energy should be ((.3)(30)+(.6)(50)+(.1)(70)) = 46keV, because the fractions should add up to 1.0. However, the consequences are minor, and it will be OK if you use 1.9 cm$^{-1}$.
Thanks to David Liaguno for pointing this out.
2. I realize that, given the limited time, B-5 could use one additional hint. While this is a pure geometry problem, there are multiple ways to approach it.
One path to the solution is to calculate two auxiliary points: The intersection of the LOC with the x-axis (call it maybe $x_i$) and the point on the LOC closest to the origin (call it maybe $(x_1, y_1)$). Next, you can easily determine the length of the triangle base from $(x_i, 0)$ to $(x_0, y_0)$ and derive the equation for $y_0$. The rest follows by substitution.
|
2019-07-20 07:16:16
|
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|
https://www.codebymath.com/index.php/welcome/lesson/dist-formula-variables
|
# Lesson goal: The distance formula with variables
Previous: Calculate a tip (with keyboard input) | Home | Next: Changing a variable in one line
In a past lesson, the distance formula as covered, which is $d=\sqrt{(x-x_0)^2+(y-y_0)^2}$. This formula will tell you the "straight line" distance between any two points on a cartesian coordinate system. As this formula is stated, one point will be $(x,y)$ and the other will be $(x_0,y_0)$.
The implementation in the past lesson was a bit cumbersome. Using variables makes it much more convenient. In this lesson, we'll see if you can program and use the distance formula using variables.
# Now you try. Use the print statement to find the distance between two xy points using the variables defined.
You have to admit, the variables make this distance formula program very clear to read and easy to use! But this is the power of variables! Dismiss.
Show a friend, family member, or teacher what you've done!
|
2021-02-27 22:25:46
|
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|
https://gomathanswerkey.com/texas-go-math-grade-5-lesson-2-6-answer-key/
|
# Texas Go Math Grade 5 Lesson 2.6 Answer Key Divide by 2-Digit Divisors
Refer to our Texas Go Math Grade 5 Answer Key Pdf to score good marks in the exams. Test yourself by practicing the problems from Texas Go Math Grade 5 Lesson 2.6 Answer Key Divide by 2-Digit Divisors.
## Texas Go Math Grade 5 Lesson 2.6 Answer Key Divide by 2-Digit Divisors
Unlock the Problem
Mr. Yates owns a smoothie shop. To mix a batch of his famous smoothies, he uses 18 ounces of orange juice. Each day he uses 560 ounces of orange juice. how many batches of smoothies can Mr. Yates make in a day?
• Underline the sentence that tells you what you are trying to find.
• Circle the numbers you need to use.
Divide. 560 ÷ 18
Estimate. 540 ÷ 18 = 30
STEP 1: Use the estimate to place the first digit in the quotient
The first digit of the quotient will be in the ten’s place.
STEP 2: Divide the tens.
Check. 2 tens cannot be shared among 18 groups without regrouping.
STEP 3: Divide the ones.
Since 31 is close to the estimate of 30, the answer is reasonable.
So, Mr. Yates can make 30 batches of smoothies each day.
Math Talk
Mathematical Processes
Explain what the remainder 2 represents.
The remainder “2” represents the number of cups of orange juice after the number of batches of smoothies Mr. Yates make in a day
Example
Every Wednesday, Mr. Yates orders fruit. He has set aside $1,250 to purchase Valencia oranges. Each box of Valencia oranges costs$41.
How many boxes of Valencia oranges can Mr. Yates purchase?
It is given that
Every Wednesday, Mr. Yates orders fruit. He has set aside $1,250 to purchase Valencia oranges. Each box of Valencia oranges costs$41.
So,
The number of boxes of Valencia oranges can Mr. yates purchase = $$\frac{1,250}{41}$$
= 30.48
≅ 31 boxes
Divide. 1,250 ÷ 41
So, Mr. Yates can buy 30 boxes of Valencia oranges.
Share and Show
Question 1.
The given division expression is: 620 ÷ 28
Now,
Hence, from the above,
We can conclude that
620 ÷ 28 = 22 R 4
Question 2.
The given division expression is: 842 ÷ 64
Now,
Hence, from the above,
We can conclude that
842 ÷ 64 = 13 R 10
Question 3.
The given division expression is: 2,340 ÷ 53
Now,
Hence, from the above,
We can conclude that
2,340 ÷ 53 = 44 R 8
Question 4.
723 ÷ 31
The given division expression is: 723 ÷ 31
Now,
Hence, from the above,
We can conclude that
723 ÷ 31 = 23 R 10
Question 5.
1,359 ÷ 45
The given division expression is: 1,359 ÷ 45
Now,
Hence, from the above,
We can conclude that
1,359 ÷ 45 = 30 R 9
Question 6.
7,925 ÷ 72
The given division expression is: 7,925 ÷ 72
Now,
Hence, from the above,
We can conclude that
7,925 ÷ 72 = 110 R 5
Problem Solving
Question 7.
775 ÷ 35
The given division expression is: 775 ÷ 35
Now,
Hence, from the above,
We can conclude that
775 ÷ 35 = 22 R 5
Question 8.
820 ÷ 41
The given division expression is: 820 ÷ 41
Now,
Hence, from the above,
We can conclude that
820 ÷ 41 = 20
Question 9.
805 ÷ 24
The given division expression is: 805 ÷ 24
Now,
Hence, from the above,
We can conclude that
805 ÷ 24 = 33 R 13
Question 10.
1,166 ÷ 53
The given division expression is: 1,166 ÷ 53
Now,
Hence, from the above,
We can conclude that
1,166 ÷ 53 = 22
Question 11.
1,989 ÷ 15
The given division expression is: 1,989 ÷ 15
Now,
Hence, from the above,
We can conclude that
1,989 ÷ 15 = 132 R 9
Question 12.
3,927 ÷ 35
The given division expression is: 3,927 ÷ 35
Now,
Hence, from the above,
We can conclude that
3,927 ÷ 35 = 112 R 7
Question 13.
Why can you use multiplication to check division? Explain.
Division and multiplication are inverse or opposite operations. You can use multiplication to check your division answer this way. If there is a remainder, add it to the multiplication product. Compare this answer to the dividend
Problem Solving
Use the list at the right to solve 14-16.
Question 14.
A smoothie shop receives delivery of 980 ounces of grape juice. How many Royal Purple smoothies can be made with grape juice?
It is given that
A smoothie shop receives delivery of 980 ounces of grape juice
Now,
The given information is:
Now,
From the above,
We can observe that
To make the Royal Purple Smoothie,
We need 22 ounces of grape juice
So,
The number of Royal Purple smoothies can be made with grape juice = (The total number of ounces of grape juice) ÷ (The number of ounces of grape juice in the Royal Purple Smoothie)
= $$\frac{980}{22}$$
Now,
By using the Long Division,
Hence, from the above,
We can conclude that
The number of Royal Purple smoothies that can be made with grape juice is: 44 Royal Purple Smoothies
Question 15.
H.O.T. Multi-Step The shop has 1,260 ounces of cranberry juice and 650 ounces of passion fruit juice. If the juices are used to make Crazy Cranberry smoothies, which juice will run out first? How much of the other juice will be leftover?
It is given that
The shop has 1,260 ounces of cranberry juice and 650 ounces of passion fruit juice.
Now,
The given information is:
Now,
From the above,
We can observe that
In Cranberry Smoothie,
The number of ounces of cranberry juice is: 20 ounces
The number of ounces of passion fruit juice is: 10 ounces
Now,
The total number of ounces of cranberry juice = $$\frac{1,260}{20}$$
= 63 ounces
The total number of ounces of passion fruit juice = $$\frac{650}{10}$$
= 65 ounces
So,
The total number of ounces that is leftover = 65 – 63
= 2 ounces
So,
63 ounces < 65 ounces
Hence, from the above,
We can conclude that
The cranberry juice will run out first
The amount of the other juice that will be leftover is: 2 ounces
Question 16.
H.O.T. In the refrigerator, there are 680 ounces of orange juice and 410 ounces of mango juice. How many Orange Tango smoothies can be made? Explain your reasoning.
It is given that
In the refrigerator, there are 680 ounces of orange juice and 410 ounces of mango juice
Now,
The given information is:
Now,
From the above,
We can observe that
In Orange Tango Smoothie,
The number of ounces of orange juice is: 18 ounces
The number of ounces of mango juice = 12 ounces
So,
The number of Orange Tango smoothies that can be made = $$\frac{680 + 410}{18 + 12}$$
= $$\frac{1,090}{30}$$
Now,
Hence, from the above,
We can conclude that
The number of Orange Tango smoothies that can be made is: 36 Smoothies
Question 17.
A shipment of 572 scented erasers has arrived at the school store. You want to sell them in sets of 15. How many full sets of erasers can you make?
(A) 40
(B) 38
(C) 39
(D) 37
It is given that
A shipment of 572 scented erasers has arrived at the school store. You want to sell them in sets of 15.
Now,
According to the given information,
The number of full sets of erasers you can make = $$\frac{572}{15}$$
Now,
Hence, from the above,
We can conclude that
The number of full sets of erasers you can make is:
Question 18.
Darius counted that he walks 864 steps from his house to the bookstore. If Darius takes 52 steps each minute, how long will it take him to reach the bookstore?
(A) 31 minutes
(B) 17 minutes
(C) 13 minutes
(D) 20 minutes
It is given that
Darius counted that he walks 864 steps from his house to the bookstore. and Darius takes 52 steps each minute
So,
The amount of time it took Darius to reach the bookstore = $$\frac{864}{52}$$
Now,
Hence, from the above,
We can conclude that
The amount of time it took Darius to reach the bookstore is:
Question 19.
Multi-Step The school store has 1,262 bouncy balls. The bouncy balls are packaged in sets. Any single bouncy ball is sold for $1. If all the bouncy balls sell, which of the following will give the store the best profit? (A) Sets of 25 for$13
(B) Sets of 16 for $9 (C) Sets of 12 for$7
(D) Sets of 10 for \$6
Texas Test Prep
Question 20.
James has 1,836 marbles. He decides to divide them equally among 23 boxes. How many marbles will James have leftover?
(A) 19
(B) 23
(C) 90
(D) 79
It is given that
James has 1,836 marbles. He decides to divide them equally among 23 boxes
Now,
The number of marbles in each box = 1,836 ÷ 23
Now,
So,
The number of marbles that are leftover is: 19
Hence, from the above,
We can conclude that
The number of marbles will James have leftover is:
### Texas Go Math Grade 5 Lesson 2.6 Homework and Practice Answer Key
Question 1.
The given division expression is: 783 ÷ 18
Now,
By using the Long Division,
Hence, from the above,
We can conclude that
783 ÷ 18 = 43 R 9
Question 2.
The given division expression is: 4,722 ÷ 22
Now,
By using the Long Division,
Hence, from the above,
We can conclude that
4,722 ÷ 22 = 214 R 14
Question 3.
The given division expression is: 891 ÷ 56
Now,
By using the Long Division,
Hence, from the above,
We can conclude that
891 ÷ 56 = 15 R 51
Question 4.
The given division expression is: 3,192 ÷ 19
Now,
By using the Long Division,
Hence, from the above,
We can conclude that
3,192 ÷ 19 = 168
Question 5.
The given division expression is: 173 ÷ 63
Now,
By using the Long Division,
Hence, from the above,
We can conclude that
173 ÷ 63 = 2 R 47
Question 6.
The given division expression is: 8,382 ÷ 43
Now,
By using the Long Division,
Hence, from the above,
We can conclude that
8,382 ÷ 43 = 192 R 40
Question 7.
The given division expression is: 5,109 ÷ 39
Now,
By using the Long Division,
Hence, from the above,
We can conclude that
5,109 ÷ 39 = 131
Question 8.
The given division expression is: 832 ÷ 32
Now,
By using the Long Division,
Hence, from the above,
We can conclude that
832 ÷ 32 = 26
Question 9.
The given division expression is: 573 ÷ 14
Now,
By using the Long Division,
Hence, from the above,
We can conclude that
573 ÷ 14 = 40 R 13
Explain.
Question 10.
You can check your answer to a division problem by using multiplication. How can you check the answer when a division problem has a remainder?
When a math problem has a remainder, it just means that there is a number left over after the division is done. To check your answer, just multiply your quotient and divisor and add your remainder. Your total should match the number you started with.
Problem Solving
Question 11.
Leon has 1,353 bottle caps in his collection. He decides to divide them evenly among 47 boxes. How many bottle caps will Leon have leftover?
It is given that
Leon has 1,353 bottle caps in his collection. He decides to divide them evenly among 47 boxes
So,
According to the given information,
The number of bottle caps will Leon have = $$\frac{1,353}{47}$$
Now,
Now,
We know that,
The remainder will represent the “Leftovers”
Hence, from the above,
We can conclude that
The number of bottle caps will Leon have leftover is: 37 bottle caps
Question 12.
It takes 48 ounces of vegetable broth to make a pot of Chef Zoe’s minestrone soup. How many pots of soup can be made with 432 ounces of broth?
It is given that
It takes 48 ounces of vegetable broth to make a pot of Chef Zoe’s minestrone soup
So,
According to the given information,
The number of pots of soup that can be made from 432 ounces of broth = $$\frac{432}{48}$$
Now,
Hence, from the above,
We can conclude that
The number of pots of soup that can be made from 432 ounces of broth is: 9 pots of soup
Lesson Check
Question 13.
Tamera has a rubber band ball made of 3,241 rubber bands. How many complete smaller rubber band balls can she make if each small ball is made of 80 bands?
(A) 28
(B) 40
(C) 53
(D) 41
It is given that
Tamera has a rubber band ball made of 3,241 rubber bands and each small ball is made of 80 bands
So,
According to the given information,
The number of complete smaller rubber band balls Tamera can make = $$\frac{3,241}{80}$$
Now,
Hence, from the above,
We can conclude that
The number of complete smaller rubber band balls Tamera can make is:
Question 14.
Sam picks out a book that has 468 pages. He wants to finish the book in 36 days. If he reads the same number of pages each day, how many pages should he read?
(A) 23
(B) 11
(C) 13
(D) 11
It is given that
Sam picks out a book that has 468 pages. He wants to finish the book in 36 days
S0,
According to the given information,
The number of pages Sam should read = $$\frac{468}{36}$$
Now,
Hence, from the above,
We can conclude that
The number of pages Sam should read is:
Question 15.
A baker has 834 fluid ounces of muffin batter. Each muffin needs 12 fluid ounces of batter. How many muffins can the baker make?
(A) 70
(B) 69
(C) 68
(D) 65
It is given that
A baker has 834 fluid ounces of muffin batter. Each muffin needs 12 fluid ounces of batter
So,
According to the given information,
The number of muffins the baker can make = $$\frac{834}{12}$$
Now,
Hence, from the above,
We can conclude that
The number of muffins the baker can make is:
Question 16.
Springfield has an aquarium that holds 336 gallons of water. It takes 24 hours to fill the aquarium. How many gallons of water fill the aquarium each hour?
(A) 16 gallons
(B) 14 gallons
(C) 15 gallons
(D) 13 gallons
It is given that
Springfield has an aquarium that holds 336 gallons of water. It takes 24 hours to fill the aquarium.
So,
According to the given information,
The number of gallons of water fill the aquarium each hour = $$\frac{336}{24}$$
Now,
Hence, from the above,
We can conclude that
The number of gallons of water fill the aquarium each hour is:
Question 17.
Multi-Step A juice bar has 768 ounces of passion fruit juice and 810 ounces of berry juice. Passion fruit juice is sold in 16-ounce cups. Berry juice is sold in 18-ounce cups. Which statement is true? ‘
(A) The juice bar can sell 3 more cups of berry juice than passion fruit juice.
(B) The juice bar can sell the same number of cups of berry juice and passion fruit juice.
(C) The juice bar can sell fewer than 90 total cups of berry juice and passion fruit juice.
(D) The juice bar can sell 3 more cups of passion fruit juice than berry juice.
It is given that
A juice bar has 768 ounces of passion fruit juice and 810 ounces of berry juice. Passion fruit juice is sold in 16-ounce cups. Berry juice is sold in 18-ounce cups
So,
According to the given information,
The number of ounces of passion fruit juice = $$\frac{768}{16}$$
= 48
The number of ounces of Berry juice = $$\frac{810}{18}$$
= 45
Now,
The difference between the number of ounces of passion fruit juice and Berry juice = 48 – 45 = 3 ounces
Hence, from the above,
We can conclude that
The statement that is true is:
Question 18.
Multi-Step A city has 7,204 recycling bins. The city gives half of the recycle bins to its citizens. The rest of the recycle bins are divided into 23 equal groups for city parks. How many recycle bins are left over?
(A) 14
(B) 156
(C) 138
(D) 28
The number of recycle bins that are leftover = $$\frac{7,204 ÷ 2}{23}$$
= $$\frac{3,602}{23}$$
|
2022-05-22 11:05:28
|
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|
https://exoctk.stsci.edu/phase_constraint
|
# Phase Constraint Calculator
Due to uncertainties on the exact scheduling time of JWST observations, users are strongly encouraged to input minimum and maximum phases on the APT "Timing" requirements under the "Special Requirements" section when planning their observations. This gives the observatory a range of time (the "Window Size"; which should be of one hour or larger in order to not incur into direct scheduling overheads) on which observations might start. This is illustrated in the following diagram:
The Phase Constraint Calculator provides a simple interface for calculating this JWST observation window for direct input on APT. This tool always assumes the zero-phase is at mid-transit, and thus that value is the one that should be input under "Zero phase (HJD)" in APT. Users can either resolve target properties from exo.MAST using the "Resolve Target" button below or input their own. If using the former, users are strongly encouraged to check that the retrieved properties are up-to-date.
The name of a target to resolve in ExoMAST
$$\small \text{Days}$$
Period of Target
(Only used to compute secondary eclipse time/phase constraints)
$$\small \text{Degrees}$$
Argument of periastron passage (only used to compute secondary eclipse time/phase constraints)
$$\small \text{Degrees}$$
Inclination of the orbit (only used to compute secondary eclipse time/phase constraints)
Calculate constraint for primary transits or secondary eclipses?
$$\small \text{Hours}$$
Time planned to be spent on target prior to mid-transit/eclipse (Default: 0.75 Hr + Max(1 Hr + T14/2, T14) when using Resolver)
$$\small \text{Hours}$$
Size of observation start window (Default 1 hour)
Calculate Phase Constraints for Target.
$$\small \text{BJD or HJD}$$
Time of transit-center of target (this goes under "Zero Phase" in APT). Automatically fills when hitting "Resolve Target".
Minimum Phase of Observation
Maximum Phase of Observation
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2022-09-25 15:31:29
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http://www.ck12.org/book/CK-12-Probability-and-Statistics-Concepts/r133/section/9.0/
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<meta http-equiv="refresh" content="1; url=/nojavascript/"> The Normal Distribution | CK-12 Foundation
You are reading an older version of this FlexBook® textbook: CK-12 Probability and Statistics Concepts Go to the latest version.
# Chapter 9: The Normal Distribution
Created by: CK-12
The normal distribution can be found practically everywhere, from the distribution of human heights to IQ scores. Understanding the application of the normal distribution can simplify the calculation of binomial probabilities, such as the probability of flipping heads 37 or more times out of 60. By using the Central Limit Theorem, you can evaluate the probabilities associated with many different random variables.
## Chapter Outline
### Chapter Summary
Students practiced the application of the normal distribution, and were introduced to the Empirical rule and the concept and calculation of z-scores. Z-score probabilities were introduced, and students practiced associating z-scores with probabilities via reference tables and technology. The concept of the sampling distribution of the sample mean was introduced, along with the Central Limit Theorem. Finally, students practiced using the normal distribution to approximate the output of binomial random variables.
Jun 18, 2013
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2014-07-29 04:55:56
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