$ cat topost | sha256sum 1e7c2e0e2352235a5f0f537a2c434b3f73307c91923da47762e873c14b187e80 –

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More on b-numbers, part B

This is a continuation of the previous post on b-numbers. === For a b-number ‘x’ in the range 4096 to 8191 (13 bit length), it appears at first glance that, modulo 4096, x == y (mod 4096), where y is a b-number in the range 1-4095; Details:   k up to 4095:   5 //… Continue reading More on b-numbers, part B

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The b-numbers again

If we write the (hypothetical, from now on understood) sequence from TM #4 (chaotic), 5-state, 2-symbol tape of Marxen and Buntrock in rows of 8, the 3rd column has a complex structure. Suppose we use “index 1”-notation, which just means that the first term of the sequence, 3, is written s(1) instead of s(0) as… Continue reading The b-numbers again

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C source code to current TM #4 (chaotic) simulator

The code compiles and executes without problems using the GCC compiler on architecture x86_64 on Linux. It only needs the standard C library. It’s an accelerated simulator that combines many repated operations into one big operation. It was checked against a conventional un-accelerated TM simulator, and the outputs matched. (no name program, or sim12g84.c locally):… Continue reading C source code to current TM #4 (chaotic) simulator

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Patterns in the b’-numbers related to TM #4 (chaotic) presumptive sequence

Patterns in the b’-numbers related to TM #4 (chaotic) presumptive sequence   b’ numbers = ((( {1, 2, 3, 4, 5, 6, 7} Union the following disjoint sets, one per number of bits in the base 2 representations of these numbers, 4 bits for v8, 5 bits for v16, 6 bits for v32, 7 bits… Continue reading Patterns in the b’-numbers related to TM #4 (chaotic) presumptive sequence

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The sequence of “b-numbers” determines some values in Column 3 of the TM #4 presumptive sequence

For a b-number ‘b’ , empirically, s(2^m – b – 2) = 2^m – b, as long as b > 0 (always true) AND b < 2^(m-1). Being connected to Column 3 of 8, a “b-number” b is such that b == 3 (mod 8). A b-number ‘b’ predicts relationships of the type: s(y) =… Continue reading The sequence of “b-numbers” determines some values in Column 3 of the TM #4 presumptive sequence

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The 234 allowable numbers of bit-length 16 for TM #4 (chaotic)

1000000110110101 l16 1000011111101101 l16 1000101101110101 l16 1000101111110101 l16 1000110011101101 l16 1000110110110101 l16 1000111011010101 l16 1001000110110101 l16 1001001011010101 l16 1001010111010101 l16 1001011011101101 l16 1001011110110101 l16 1001011111101101 l16 1001100111101101 l16 1001101011111101 l16 1001101101110101 l16 1001101111110101 l16 1001110011101101 l16 1001110110110101 l16 1001110111101101 l16 1001111011010101 l16 1001111011111101 l16 1001111101110101 l16 1001111111110101 l16 1010000110110101 l16 1010001011010101 l16 1010010111010101 l16 1010011011101101… Continue reading The 234 allowable numbers of bit-length 16 for TM #4 (chaotic)

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List of the 543 atomic forbidden numbers of bit-length 18

100000000000000101 l18 100000000000001101 l18 100000000000010101 l18 100000000000011101 l18 100000000000100101 l18 100000000000101101 l18 100000000000110101 l18 100000000000111101 l18 100000000001001101 l18 100000000001010101 l18 100000000001011101 l18 100000000001100101 l18 100000000001101101 l18 100000000001110101 l18 100000000001111101 l18 100000000010010101 l18 100000000010101101 l18 100000000010110101 l18 100000000010111101 l18 100000000011001101 l18 100000000011010101 l18 100000000011011101 l18 100000000011100101 l18 100000000011101101 l18 100000000011110101 l18 100000000011111101 l18 100000000100110101 l18 100000000101010101… Continue reading List of the 543 atomic forbidden numbers of bit-length 18

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List of the first 200 atomic forbidden numbers for TM #4 (chaotic)

1000101 10000101 10001101 10011101 10100101 100000101 100001101 100010101 100011101 100100101 100101101 100111101 101001101 101011101 101100101 1000000101 1000001101 1000010101 1000011101 1000100101 1000101101 1000110101 1000111101 1001001101 1001010101 1001011101 1001100101 1001101101 1001111101 1010010101 1010101101 1010111101 1011001101 1011011101 1011100101 10000000101 10000001101 10000010101 10000011101 10000100101 10000101101 10000110101 10000111101 10001001101 10001010101 10001011101 10001100101 10001101101 10001110101 10001111101 10010010101 10010101101 10010111101 10011001101 10011011101… Continue reading List of the first 200 atomic forbidden numbers for TM #4 (chaotic)

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List of exceptions

These are exceptions to the general rule that n1 >= n0 , that the count of 1 bits is equal to or greater than the count of 0 bits in the base 2 representation of numbers in the hypothetical sequence computed by TM #4 chaotic, 5-state, Marxen and Buntrock, 1990. Please refer to previous post… Continue reading List of exceptions

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Variation on 23. Nc5 in Anand-Kovalyov round 2 game

The variation begins with: 23. Ra8 Rxb7 24. Rda1 , which sets up connected white rooks on the A-file on A1 and A8. ================================================================= [Event “World Cup 2017”] [Site “Tbilisi”] [Date “2017.09.06”] [Round “9.10”] [White “Anand Viswanathan (IND)”] [Black “Kovalyov Anton (CAN)”] [Result “0-1”] [ECO “B90”] [WhiteElo “2794”] [BlackElo “2649”] [Annotator “,david250DavidBernier”] [PlyCount “86”] [EventDate… Continue reading Variation on 23. Nc5 in Anand-Kovalyov round 2 game

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On asymptotics of some large character sums

On asymptotics of some large character sums. ================================================= Added Monday January 1, 2018: FOREWORD: I now consider what follows this foreword as numerical data on some large character sums. The implied asymptotic constant , 2*(exp(Euler)/Pi)^2 , is not backed by any theoretical work. I had a few email exchanges with Andrew Granville about asymptotics of… Continue reading On asymptotics of some large character sums

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An improved PARI/gp script for solving the Lorenz ODE system

Today, I’m posting a variant of the PARI/gp script to solve the Lorenz system of differential equations. The use of factorials and binomial coefficients has been eliminated, so I’d expect it to run somewhat faster than the script from an earlier post.   The lorenzy4.gp PARI/gp script:   Lorenz(X0, Y0, Z0) = { order =… Continue reading An improved PARI/gp script for solving the Lorenz ODE system

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Blog accepting comments

That’s my intention, you can ask questions, answer questions, etc. once I have this figured out. David Bernier  

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PARI/gp script for Lorenz system

The Lorenz system of differential equations is challenging to solve over extended periods of of time ‘t’, the independent variable. In “Long-Time Computability of the Lorenz System”, the authors Kehlet and Logg from Norway give a numerical solution for x(t), y(t), z(t) for t in [0, 1000] and with initial values x(0) = 1, y(0)… Continue reading PARI/gp script for Lorenz system

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Moalic and Gondran Heuristic rope team : a parallel algorithm for graph coloring (for DSJC500.5 graph)

I’ve got C code that seems to work quite well for their new algorithm, comparatively speaking, meaning compared to what I had before. I’m regularly getting improper 47-colorings of DSJC500.5 with just two conflicting vertices, which means precisely one edge with a conflict. It’s as close as it gets without having no conflicts, unless I’m… Continue reading Moalic and Gondran Heuristic rope team : a parallel algorithm for graph coloring (for DSJC500.5 graph)

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Data of July 14 to test HEA in Duet, version HEAD’

As explained in the previous post, the C language program that implements the HEAD’ graph coloring algorithm of Moalic and Gondran needs as input the graph DSJC500.5.col (DIMACS challenge) in a format detailed previously, as well as a file of 14 “improper 48-colorings” of DSJC500.5, meaning 48-colorings of the 500 vertices of DSJC500.5, where about… Continue reading Data of July 14 to test HEA in Duet, version HEAD’

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Source code of July 14 to test HEA in Duet, version HEAD’

The source code file, pnewtbuza75a.c , can be compiled using the GCC compiler as follows: gcc -lm -O2 -o pnewtbuza75a.out pnewtbuza75a.c To run the program, at the Unix shell prompt, I type: ./pnewtbuza75a.out DSJC500.5.mt 500 DSJC500.5.mt is a file containing a description of the 500-vertex DSJC500.5 graph created by David Johnson. In substance, it can… Continue reading Source code of July 14 to test HEA in Duet, version HEAD’

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HEA in Duet and graph coloring (continuation)

There were some mistakes and some inefficiencies in my C implementation of the HEAD’ variation of HEA in Duet of Moalic and Gondran (please see previous post). In their arxiv preprint, they propose a hybrid evolutionary algorithm for graph coloring which is really quite sophisticated, and building on earlier work of Galinier and Hao, among… Continue reading HEA in Duet and graph coloring (continuation)

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Preparation for writing the evolutionary algorithm code

I intend to write code to implement the HEAD or HEAD’ algorithm for graph coloring of Moalic and Gondran: “Variations on Memetic Algorithms for Graph Coloring Problems”, https://arxiv.org/abs/1401.2184 . There, they use the Greedy Partition Crossover or GPX crossover , and their hybrid Tabu Search + evolutionary method is inspired by Galinier and Hao’s HEA… Continue reading Preparation for writing the evolutionary algorithm code

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newtabuzz99a.c for DIMACS graph DSJC500.5.col

The program uses the improved tabu search from: Galinier and Hao (1999): “Hybrid evolutionary algorithms for graph coloring” . For maximum variability in the colorings, it starts each time with a random 500-coloring of the 500-vertex graph. Starting from a valid k-coloring, a (k-1)-coloring, not necessarily valid, is obtained by distributing the elements of one… Continue reading newtabuzz99a.c for DIMACS graph DSJC500.5.col

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newtabuzf99a.c for DIMACS DSJC500.5.col

This is my best effort at implementing Galinier and Hao’s Tabu Search algoritm from their 1999 paper: “Hybrid Evolutionary Algorithms for Graph Coloring”. It produces 50-colorings of DSJC500.5.col after a few hours. Filename:   newtabuzf99a.c   #include <stdio.h> #include <stdlib.h> #include <math.h> #define MAX_VERTEX 1000 #define MAX_COLORS 500 int adj_mat[MAX_VERTEX][MAX_VERTEX]; int Gamma[MAX_VERTEX][MAX_COLORS]; int Fast_Gamma[MAX_VERTEX][MAX_COLORS]; int tabu_list[MAX_VERTEX][MAX_COLORS];… Continue reading newtabuzf99a.c for DIMACS DSJC500.5.col

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This guy has my vote: libreadline cleanup

[root@localhost ~]# cd /usr/local/lib I had built and installed a non-system readline library as root in /usr/local/lib . As far as I can tell, the system readline library is in the file: /lib64/libreadline.so.6.0 Running # ldd -d -r /lib64/libreadline.so.6.0 linux-vdso.so.1 =>  (0x00007ffd0139b000) libtinfo.so.5 => /lib64/libtinfo.so.5 (0x0000003e73200000) libc.so.6 => /lib64/libc.so.6 (0x0000003752000000) /lib64/ld-linux-x86-64.so.2 (0x0000003751c00000) gives no unresolved… Continue reading This guy has my vote: libreadline cleanup

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Re: “Best candidate” graph, 14 vertices, udg

The post from a few weeks ago shows a 14-vertex 33-edge probable unit distance graph with 324 4-colorings. The URL of that blog post = “Best candidate” graph, 14 vertices, udg

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My first test-drive using exiftool on Windows

I had read that EXIF metadata in files that are images, whether .jpg or other file formats, have embbedded data, sometimes inluding geotags (coordinates). Below is the copy/paste of my first test running exiftool.exe on Windows 10: C:\Users\abcde\Downloads> C:\Users\abcde\Downloads\exiftool -All Louvre_Museum_Wikimedia_Commons.jpg ExifTool Version Number : 10.45 File Name : Louvre_Museum_Wikimedia_Commons.jpg Directory : . File Size… Continue reading My first test-drive using exiftool on Windows

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A 12-vertex, 26-edge, probable unit distance graph

The 12-vertex, 26-edge graph shown above is not 3-colorable, and is 4-colorable in 178 ways, up to permutation of the four colors. Numerical evidence suggests that it is a unit distance graph, i.e. embeddable in the plane with all edges of unit length. My unit distance graph solver found no 12-vertex, non 3-colorable, 4-colorable udg… Continue reading A 12-vertex, 26-edge, probable unit distance graph

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