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Diary, January 2007

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Wednesday, January 3, 2007

Playing Go at Ton's place

Today, I went to play Go at Ton's place. I had brought my own set with me. When I arrived he already was playing with Juri, who too had brought a set with him. I watched them for some time, until Taco arrived and then started a game against Taco. I was given eight stones ahead. A finally lost the game with about thirty points, mainly due to the fact that I lost one of my groups in the corner. For the rest I succeded in connecting all my stones, while Taco had about five smaller groups. Rudi and Marcel also had arrived and were playing some game against each other. When we were all finished (Ton and Juri played two games), we looked at some kind of game (whoes name I forgot) that Ton had standing on top of his television. I tried to play it against Ton, but not fully comprehend the goal of the game. Then Rudi and Taco started to play against each other and Marcel against Juri. When I wanted to leave, I discovered that Rudi and Taco were playing on my playing board, which made me decide to wait and watch their game. (Of course, I could have asked them to switch to another playing board, as they were not so far into their game yet, and they both can easily remember games.) Not much later the mother of Juri arrived to catch him. But he wanted to continue his game. Marcel finally resigned. We all left shortly after twelve.

Friday, January 5, 2007

Blue foam bricks

Yesterday, Annabel received an answer to the email she send on December 29, 2006 to the company from which Ton got the blue foam bricks. The answer said that she could go to the company to collect the last bag with blue foam bricks. Yesterday evening, I showed her how to get there using Google Earth, and this afternoon she went there with a number of bags. About an hour later she came back with full bags being taped to her bike. She also got a pen for free.

Monday, January 8, 2007

Revenge of the Nerds

Today, I discovered that the program "Revenge of the Nerds", which deals about the Nerd twin Erik and Arjan, who also joined the Dutch "Beauty and the Nerd", already started. This evening, Annabel and I watched the first episode from the internet, and watched, together with Li-Xia, the second episode on television. In the first episode the twin had to speed date twentyfive girls and pick a girl with whom they wanted to have a dream date. At one point one of the twins hit his big-pen against his head because he wanted to write something down. Annabel had to laugh about it, and reversed to see it another two times. In the second episode they learned some thai kick boxing and had to fight against each other and the went to a flirt coach.


Tuesday, January 9, 2007

Chinese Wooden Puzzle

The program for calculating the number of ways the puzzle can be filled with the 3 by 10 solutions and the 5 by 6 solutions such that no pieces with the same colour touch each other, needed about 126 hours to finish. That is about twice as long as I had estimated on December 28, 2006. (Source of the program.) The result are: On November 9, 2006, I calculated that the total number of unique ways for filling a 15 by 10 frame with 3 by 10 and 5 by 6 solutions was 962,444,349,067,755,520. This means that about 0.81% of all solutions do not have touching colours. This is lower than the about 1.28% that I found on December 25 when only the 3 by 10 solutions were used.


Wednesday, January 10, 2007

Spring has come

The birds are singing in the morning and the flowers are budding. Yesterday was the warmest day on record. The average temperature in the center of the country was 12.9 degrees Celsius, which is one degree more than the previous record for the warmest day in January, which was on January 5, 1957. The minimum temperature, 11.8 degrees Celsius, was also a new record for January. This is all caused by a depression, which slowly heading from the West and going to give us a storm the coming days.


Today, Andy came home with a Pokémon playing card. It was the Marshtomp card of the Pokémon Trading Card Game. (Marshtomp on Wikipedia).

Playing Go

This evening, Annabel and I went to the university to play Go. We also brought the Chinese Wooden Puzzle with us. When we arrived only Juri was there. He tried to solve the Chinese Wooden Puzzle, but failed. When Ton arrived, he first invited Annabel, but Annabel did not want to play, and next invited me. I was given a six stone advance. Some others arrived, and finally, Annabel started a game against Taco with nine stones advance. She lost with about seventy points. Really not that bad. Ton and I had some serious fights, and at the end it looked like I was going to win, but after Ton made a Monkey Jump, and I let him connect in the other direction, I was able to kill the group from which he made the jump because he made a mistake. After which he resigned. Araldo made the Chinese Wooden Puzzle.

Saturday, January 13, 2007

First Pet

This morning, Annabel went to the shop to buy a small aquarium and then she got a small fish from one of the neighbour girls. It is about one and half centimeter long.

Book sale

This afternoon I went into the city, as I often do. Many shops were have a sale. So did the two book shops I visited. In bookshop De Slegte I bought two books. I bought "Ik deserteur van een braaf autistenras. Nieuwe berichten aan het volk van de bovenwereld" a translation of "Ich Deserteur einer artigen Autistenrasse. Neue Botschaften an das Volk der Oberwelt" (I deserter of an obdiebt race of autists. New messages to the people of the upper world") by Birger Sellin for € 1.00. I also have a translation of his first book (English title: "Don't Want to Be Inside Me Anymore: Messages from Autistic Mind"). The second book I bought is "Monet" by Vanessa Potts. I already bought this book on Tuesday, April 23, 2002. I bought it because it only costed € 2.00.

In bookshop Broekhuis, I also bought two books. First I bought "Mijn dinsdagen met Morrie" ("Tuesdays with Morrie") by Mitch Albom for € 3.75. Next I bought "Tekno Logical" for € 7.50. Inside the book, I found two copies of the CD-ROM with images.

Lassie and Baltasar are missing

This evening, when we brought Andy to bed, we discovered that Lassie and Baltasar, his cuddly toys were missing. We searched everywhere, but could not find them. He also does not know himself where they are.


Chinese Wooden Puzzle

Yesterday evening and today, I worked on the C++ program for solving the Chinese Wooden Puzzle. In the evening the program found the first solution for the 15x7 version with the orange and yellow pieces missing. I put the solution (extended to the full 15x10 size of the puzzle with a line of orange and yellow pieces) on the page with solutions.

Sunday, January 14, 2007

Chinese Wooden Puzzle program

Today, I let the program that I developed yesterday run for seven hours. It found 21770 solutions (Zip file with solutions). Which is 0.86 solution per second (or one solution per 1.16 second). However, many of the solutions result in the same colours. If only looking at the colours there were 5926 different solutions. For one colour pattern there were 64 different solutions found, not saying that there could be many more.

Monday, January 15, 2007


Six pieces of the Netherlands are inside a piece of Belgium that lies inside the Netherlands. One other piece of the Netherlands is inside another piece of Belgium that lies inside the Netherlands. This can be found in the interesting city of Baarle-Hertog/ Baarle-Nassau. For more information, read this detailed story.

Tuesday, January 16, 2007

Building a coffin

The children of the Iederwijs school in Someren are building a coffin for Mrs. Eri van den Biggelaar, one of their teachers, and one of the founders of this Iederwijs school (a type of school comparable to Sudbury Valley School). Mrs. Van den Biggelaar (40) is currently in the final stages of an agressive form of cervical cancer. It may be a strange sight, but in the middle of the classroom stands a coffin. The children have been working on making it for weeks. The coffin is constructed from more than a hundred pieces of wood, and is almost ready. Only the lid need to be made. The children don't think it is scary or lugubrious. Quite to the opposite, the have become used to making the coffin, in which their teacher will be buried. And if they are not working on it, they climb inside and pretend it is a submarine. The teachers don't think it is a problem that they play with it. Mrs. Van den Biggelaar had to laugh about it. It was her intention that the children would deal with it so naturally. Her own children also attend the school and participate with the construction of the coffin. The design for the coffin was made by Eric van Dijk, an industrial designer, one of the teachers of the school.


This morning, I went with Annabel for the first time to an orthodontist. He noted that Annabel was a mix of races, when he told me that Li-Xia was from China he told us that he comes from a Chinese family in Indonesia and is married with a Dutch women. Later, when we left the building he remarked to a co-worker that his children look like Annabel. Before he is going to give a treatment plan, Annabel first needed to proof that she can brush her teeth correctly. Annabel was given a brushing instruction by a woman. She has to return in two weeks.

Funeral fair

When I bike back to my office, I noticed a sign along the road about a funeral fair. I have never heard of a funeral fair before. It will be on next Saturday here in Enschede.

Chinese Wooden Puzzle

I was interested in the number of solutions for a certain configuration of the Chinese Wooden Puzzle based on a solution that took me a long time to find. I let program solve the configuration (without the white and purple blocks) and it found 14618 solutions. When only looking at the colours, there are 1717 different solutions. (Zip file with them.) Four of these have 96 distinct solutions. I manually extracted the solutions that have the white pieces in the bottom left corner and the purple pieces in the right top, and found 218.

Wednesday, January 17, 2007

Dark Energy may be vacuum

In the Science Daily article "Dark Energy May Be Vacuum", it says: "The new data shows that none of the fancy new theories that have been proposed in the last decade are necessary to explain the acceleration. Rather, vacuum energy is the most likely cause and the expansion history of the universe can be explained by simply adding this constant background of acceleration into the normal theory of gravity." This article is based on the article Observational Constraints on the Nature of the Dark Energy: First Cosmological Results from the ESSENCE Supernova Survey. In the abstract of this article it says simply: "The current SN Ia data are fully consistent with a cosmological constant." However, in the conclusions of the article it is phrased more carefull: "The emerging impression that the equation-of-state parameter is close to w=-1 makes it difficult to determine whether the underlying psysucs arises in the particle physics sector or from the classical cosmological constant of general relativity. A value of w=-1 is perhaps the least informative possible outcome."

Playing Go

This evening, Annabel and I went to the university to play Go. We were the first to arrive. Juri, who is usually already there, did not come today. Shorty after us, Ton arrived and we started a game where I was given six stones start. When the others arrived, Edze played four games against Annabel. During the last game he told her that it was forbidden for her to play a stone against any of his stones, just to teacher her, that she plays better if she does. I am getting the impression that Edze has some strong tutorial skills. Around ten o'clock, Ton resigned his game. Others estimated that he was about forty points behind. Relatively early in the game, I treated to kill one of his groups with a Ko. At one point he played a Ko treat without me having a direct Ko treat as a response. But I did see a big move, which would give me control over one side, whereas otherwise he would have got half of it. So, I allowed his group to live. Marcel, who came to look several times, and encouraged me to be bold when I thought I was in some serious trouble, felt that I made a number of very strong moves. Somehow, I am surprised by the improvements I am making with a minimum of efforts.

Thursday, January 18, 2007

National IQ test

Yesterday evening, when I came home, the National IQ test was on television and I watch a small part of it. When the results were announced, they told that the average score was 113. But by definition the average IQ of a group of people for a given test is 100. It looks like they did determined the IQ score on forehand. While with this kind of IQ test (where many viewers send in their results) it would be much better to determine the IQ score on all results. Per question you assign a score based on the percentage of people that gave a correct answer. For example, if x% of the people gave a correct answer, than the people who gave a correct answer, get a score of (100-x/2) and those who gave a wrong answer, get a score of x/2. For each person you calculate the average score over all the questions as the final score. Based on mean and the standard deviation of all the scores one can easily determine the IQ score of participants

I wonder if IQ test would become more accurate if one would also take into account the time that people need to answer a certain question. Just putting a time limit seems to me a rather coarse method. With the use of computers that would be rather simple. I guess you could even do this over the Internet.


This morning, I took the car to my office. I think that this was one of the first times, I went by car with no special reason other than the weather. Yesterday, I also had to bike home in the rain against the wind, and I was not in the mood to have the same experiences now that even stronger winds were predicted. During the day, it became obvious that the storm was even a little stronger than predicted. The Netherlands was in the middle of the storm (see this image of windspeeds in Europe).

My mother, who was staying with us for a day, was phoned by a younger sister, who adviced her to not go home but stay over for a night. I went home around six o'clock and did not encounter much problems. But my sister was less lucky, as she got stuck in the central train station of Amsterdam, and had to stay with a colleague of work. Her two children, age 10 and 16, had to stay home on their own. But the could phone some person in the neighbourhood if there was a problem. Especially in the West of the country there was some considerable damage. This is the strongest storm since many years. The storm was finally catagorized as "Violent storm" with Beaufort number 11.

Friday, January 19, 2007


I was only after midnight that the wind started to drop. Look at this wind profile of the past day and night. It shows the maximum wind speed in Km/hour. Note the two gabs in the graph around 17:00 and between 22:00 and 23:00. It looks that the wind was at the strongest at those times. This could be a result of the wind meter malfunctioning due to too strong winds. (Maybe it was even nocked down.)

Saturday, January 20, 2007

Going into the city

Today, Li-Xia, Annabel, and I went into the city by bike. It was raining when we went there. We first did some shoppings on the open air market. Next we went to Camel and ordered the usual Kebab dishes. Following this, Li-Xia and I went to bookshop De Slegte, where we bought a photobook with the title "Zwervend licht" (wandering light) with pictures by Jan Scholten for € 6.50. The pictures remind me of the work of Shinzo Maeda. It is a nice contribution to my collection of photobooks. As several shops we looked for Curcuma. We also looked at the shop called Comicasa that besides many comics, also sells all kinds of games, including some Go sets. I also bought the game "Schizm, Mysterious Journey" for € 4.99 and the DVD "Serenity" for € 6.99.

Monday, January 22, 2007

Nonogram to Exact Cover

This morning, I received an email from some asking me if I thought about the possibility for a mapping from Nonogram to Exact Cover. I had thought about it before, and had not found a solution, but while I was writing my reply, I came up with some ideas. I even thought about two possible mappings, but one turned out to be incorrect. It is rather obvious that you have to create a vector for each possible permutation of pieces in each of the rows and columns. To enforce that only one permutation is selected for each row and column is easy.But how to enforce that a certain selection of one permutation of each row and each column matches? I suddenly realized that this could be done by negating one of them. If n is the number of rows and m the number of columns, then the length of the vector is n+m+nm. For each permutation for row i (offset 0), we create a vector where all elements are zero, except for element i and all elements n+m+m*i+j such that element j of the permutation is black. For each permutation for column j, we create a vector where all elements are zero, except for element m+j and all element n+m+m*i+j such that element i of the permutation is white. I tested this mapping using a program written in C++. For a simple, non-trivial, Nonogram (the smallest 'hard' Nonogram), it seems to work.

A realisitic 20 by 20 nonogram resulted in Exact Cover problem with 21411 vectors of length 440. Which is a file about 10 Mbyte. I am afraid that there are not many Exact Cover solvers that can handle such a big file and efficiently find a solution.


Tuesday, January 23, 2007


The temperature suddenly dropped, till far below zero. The lowest temperature measured around her was -9.3 degrees Celsius. We happen to be in the coldest part of the country. Temperature profile of 8:00 this morning.

Alzheimer's vaccine 'in a patch'

In the BBC News article "Alzheimer's vaccine 'in a patch'" it says:

Solving an Exact Cover

Thinking about the fact that Exact Covers generated from Nonograms should be able to solve easy (even without back-tracking, if there is only a single solution, and when it is not a 'hard' problem), I got some ideas about solving Exact Covers. In case in a certain column the presence of a '1' implies the presence of a '1' in another column, then all vectors which do have a '0' in that column and a '1' in the other column, can be removed as being impossible. Looking for possible algorithms, for solving Exact Covers, I found some article using a quantum adiabatic evolution algorithm. Sounds interesting.


Learning to type

Andy is very fond of Pokemon, and often he asks me to search for images of various Pokemons. Yesterday, we tried to let him type the names in Google images search. He could do it with some help.

Wednesday, January 24, 2007


This morning, when I went into our shed to get some juice, I found the floor covered with all kinds of things. In the middle of the floor was a cotton bag, and around it were several spray paint cans. Annabel has been spray painting the cotton bag, which she got from a visit to the Bonhoeffer College Enschede, because she want to join a contest in decorating the bag. She decided that it should have a blue colour. In the past days she has been spray painting it several times. She came up with the idea herself, and also bought the spray paint cans by herself. I told her to do it in the shed because of the smell. Although I immediately ordered her to clean up the shed, I find it quite amusing.

Blood flow and Alzheimer

This morning, I came across the article "A Century Later, New Research Brings Initial Find of Alois Alzheimer to Fore Once Again", which mentions a restricted blood flow as being related to Alzheimer. This made me think about a possible relation to certain symptoms of Li-Xia. She always has had a relatively low blood pressure, which has not caused her much problems with respect to fainting and such. For many years she has been feeling cold. And of course, I also think about her eye problems. In that time she had started using Ginkgo biloba, but after the her eye problem emerged, I thought it was beter to have her stop using it.

When I did some more searching on feeling cold, I came across the term "Pernicious anemia". If i remember correctly, Li-Xia's B12 blood values were rather high. Still I find it very strange. I also remember that she used to be very sensitive to spices (lately, it seems to be less), and it could be that she had Glossitis several times.

Playing Go

This evening, Annabel and I went to the university to play Go. We were the first to arrive. Not much later Ton arrived and we decided to play a game where I got five stones ahead. I was not playing very well, and at one point, was ready to resign when Edze, who was playing against Araldo besides us, made some suggestion for a "strange" move. The move did work, and I was able to escape and save my group. Against the end of the game, I felt Ton was going to win with at least 40 points, but when we counted, the difference was only 18 points. Next time, I will get a six stones advance again. Annabel played a game against Marcel on a 13x13 board (while he was playing against Taco). Annabel got six stones in advanced and managed to win with 18 points.

Thursday, January 25, 2007


This morning, when I went outside, I saw some white lines between the tiles. First I split second I thought it was frost, but then I realized it was snow. When the light went on, I saw that there was still some very thin snow falling from the sky. The snow did only stay on certain places, and dissapeared quickly when the sun appeared.

Friday, January 26, 2007


This morning, it was snowing again. Also during the day, it snowed a little. But not much stayed on the ground, because temperatures were higher than yesterday.

Ancient mirror

This is the picture of the girl who smashed the 2,500-year-old bronze mirror, dating back to the Warring States Period of 475-221 BC. The small round mirror was gold plated, embedded with 11 turquoise stones and the whole body was coated with intricate carvings. She was showing the to the audience on China Central Television's Artwork Investment and while she transfered the wooden box that contained the mirror from one hand to the other, it fell out of it and smashed on stage. Experts rushed onto the stage to pick up the pieces as the studio audience and crew watched in stunned silence - especially owner Chen Fengjiu who was sitting in the front row. Chen, a renowned mirror collector, said: "The mirror has been part of my collection for 16 years and is the best one out of more than 1,000 mirrors." He also said it was the only one of its kind and that other collectors had offered him 1 million USD.

Saturday, January 27, 2007

Exact Cover Reducer

Today, I developed a Exact Cover Reducer: A program which can reduce certain Exact Covers by eliminating those vectors that cannot logically occur. It turnes out that Exact Covers generated from Nonograms, can be solved, if the Nonograms have a single solution and are not 'hard' problems, e.g., can be solved with simple row and column based reasoning. I tested it with an Exact Covering containing 21411 vectors of size 440 from one sample Nonogram, which produced this output file, containing the following solution (only rows):

row  1: 00000001111111000000 7
row  2: 00000010000001110000 1 3
row  3: 00000011101100011100 3 2 3
row  4: 00000000110110000110 2 2 2
row  5: 00000000000011100010 3 1
row  6: 00000011100001100110 3 2 2
row  7: 00000111110011001100 5 2 2
row  8: 00001111011010001000 4 2 1 1
row  9: 00011100101110010000 3 1 3 1
row 10: 00011010100100100000 2 1 1 1 1
row 11: 00011010010100100000 2 1 1 1 1
row 12: 00001101110100100000 2 3 1 1
row 13: 11111110001000111111 7 1 6
row 14: 11111101110001011111 6 3 1 5
row 15: 11111000000000011100 5 3
row 16: 11110010010011001111 4 1 1 2 4
row 17: 00001111000101100111 4 1 2 3
row 18: 11110011111000111110 4 5 5
row 19: 11111000000000000000 5
row 20: 11000011111111111100 2 12

Sunday, January 28, 2007

Smallest 'hard' Exact Cover with one solution

Just like there is a smallest 'hard' Nonogram, that is a Nonogram that cannot be solved by reasoning over columns and rows, and that has a single solution, there must also exist a smallest 'hard' Exact Cover with one solution. Such a Exact Cover has one solution, but cannot be reduced. The smallest I have found so far, is:


Monday, January 29, 2007

Revenge of the Nerds

Tonight was the final episode of "Revenge of the Nerds", in which the twin brothers, Erik and Arjan, were going to date the two girls that they had selected five weeks ago. I have to say that I was rather dissapointed by their behaviour. It looked like they did not learn much in the past weeks, and fell back in their old "Nerd" behaviour. One of them told his date that he was a famouse person now, and that he was often approached in the street. The girl replied that most famouse people are famouse because they have a special talent, and followed to tell that his special talent was being a nerd.

Tuesday, January 30, 2007

Open day

This evening, I went to the Open Day of the Bonhoeffer College in Enschede at the location Geessinkweg. Annabel didn't want to go with me, because she already has a preference for another location. It was quite interesting. For the new pupils they had organized all kind of small experiments/contest where they could earn some stamp. In the biology department they could look at a Daphnia under a microscope. I mentioned that I had a head louse with me, and immediately one of the teachers was interested and wanted to see it under the mircoscope. He was quite enthousiastic about it and started to ask pupils to guess what it was. Many had no idea.

This months interesting links

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