I write, therefore I am
With this variation on a famous statement by the philosopher Descartes, I would like to express that the act of writing about what happens in my life is important to me.
Friday, July 14, 2017
Tuesday, July 11, 2017
Gerrit Rietveld AcademieI went to Amsterdam, where I arrived at the central station at eleven. I took some metro's and after I short walk, I arrived around a quarter to noon at the Gerrit Rietveld Academie to look at the finals exhibition of this year. I stayed there till four in the afternoon. I found the following students with their work worth mentioning (in the order that I encountered them):
On the way how, I saw two sun dogs with a rainbow pattern. I took a picture. When I biked home from the railway station, the sky turned red and I stopped to take some pictures of which the last turned out to be the best.
BookAt 17:56, I bought the book The Game: Undercover in the Secret Society of Pickup Artists written by Neil Strauss in English and published by Canongate in 2007, ISBN:9781847672377, from charity shop Het Goed for € 1.95.
Tuesday, July 4, 2017
CataloguesWhen at charity shop Het Goed, one of the people working there, when I was looking at the art book section, pointed out that there was half a shelve of catalogues (all rather thin, more like large flyers) from Stedelijk Museum Amsterdam. As it was close to closing time, I was not able to scan all of them. I found three catalogues related to Peter Struycken. I found one of which I was sure that I already have and two that I was not sure about. At home it appeared that the one that I thought I might have, I did not have, and the one that I thought that I might not have, I did have. At 17:52, I bought the following two 'catalogues':
Sunday, July 2, 2017
NecklageI have been working on the 'necklage' solutions for the Irregular Chocolate Bar problem. The necklage solutions are the solutions with 2n-1 numbers. Let S be the sum of all numbers of a solution, than for a necklage solution the number S/n must be included and there must be n-1 pairs that add up to S/n. Furthermore, one can reason that there must be n-2 pairs and one triplet that add up to S/(n-1). All the pairs of both groups form alternating chains. One such chain connects the S/n number with the triplet and the other chain connects the two other numbers in the triplet. The could be viewed as a necklage with a 'triangle' in the front and a piece hanging down. Hence the name of these solutions. I adapted the program and it found the solutions shown below. I let it run for higher numbers as well, but it did not find any solutions that also had a division for numbers between 1 and n-1. There are good reasons to believe that these are the only necklage solutions. In the listing the minus sign is used for pairs that up to S/n and the equal sign is used for pairs and triplets that add up to S/(n-1).
3: 2-4 6= = 1-5 4: 4-5 5-4 1-8=4 9=3-6= = 9=3-6= = 9= - 2-7 1-8 2-7=5 5: 2-10=5 1-11=4 1-11=4-8 12=3-9= - 12=3-9= - 12= = 4- 8=7 5- 7=8 2-10=5-7 6: 3-17=7-13 1-19=5-15= 9 20=4-16= = 20= - 5-15=9-11 3-17=7-13=11
Museum Boijmans Van BeuningenDuring the afternoon, I visited Museum Boijmans Van Beuningen. I first looked at the main exhibition, curated by Carel Blotkamp with the new lightning designed by Peter Struycken, which he made in an attempt to approach daylight as good as is possible. To my surprise, I ran into Wim T. Schippers again. At two, I attended the official opening on the small sqaure in front of the entrance of the museum. The sky was grey and there was a little rain. After this, I also walked throught the other exhibtions: Sensory Space 11, Richard Serra, Drawings 2015-2017, The Magnetic North & The Idea of Freedom, and near the end of the afternoon, after having walked throught the exhibitions again, Gunnel Wåhlstrand. I listened to the talk by Carel Blotkamp about his work as a curator of the main exhibition. The list of noteworthy (to me) works I saw is:
AKI finals 2017In the afternoon, I went to the AKI finals 2016 exhibition at the AKI. This year, the exhibition was only in the school building. I ran into Wim T. Schippers and talked a little with him while standing at an installation by Ole Nieling. I found the following artist interesting:
Smallest maximumIn the past days, I worked on a program for calculating solutions to the Irregular Chocolate Bar problem. I discovered that it is not difficult to find solutions with using large sets of numbers where the maximum number is as small as possible. This results in the following solutions:
Finding solutions with the smallest set (of possibly larger) numbers, proved to be much harder. The method of just generating all sets, proved to be too slow. I next worked on an algorithm that would generate sets that would fit the largest number of divisions. These sets contains twice as many or one less number of numbers. But this did not get me much further. So far, I have found:
Irregular chocolate barYesterday, I saw a photo strip by Ype & Ionica about an irregular chocolate bar, inspired by bar from Tony's Chocolonely, that could nevertheless be equally shared by 1, 2, 3, 4, 5, and 6 persons. I noticed that in their design there were two pairs of pieces with the same surface area and I wondered if there was also a solution with all different numbers. I also wondered, if the more generic mathematical puzzle: find the 'smallest' set of natural numbers such it can be divided in all manners up to a given n, had been addressed by someone. On a Dutch blog by Ionica Smeets, she reports that someone named Dic Sonneveld found a solution with all different numbers, namely: 8,10,11,12,13,14,16, 17, 18, 19, 20, and 22. She also mentioned that several people concluded that there is no solution with eleven pieces. I started to do some puzzling myself and also told a colleague about the puzzle. It is obvious that the numbers for a given n should be equal to or be a multiple of the Least common multiple (or LCM) of intergers upto and including n. My colleague and I found the following solutions:
Swimming and sailingThis morning, I swam around the lake together with some other people. After having taken a shower, I went sailing with four others. We managed to return to the island with only a little use of the poles. The boats have an almost flat bottom and no keel, which makes them drift very easily, especially when there is not enough wind to make some speed. In the afternoon, I went sailing with two others. One of them jumped into the lake several times and pulled the boat while walking on the bottom of the lake. This weekend, I only played one game of Go, when Pepijn asked me to play against him. I lost with 50 against 16 points where I got nine stones ahead. But even then it is not too bad, because he is a Dan player and I also did not really concentrate a lot on the game. I did look at games being played. We also replayed the first of the 50 AlphaGo vs AlphaGo games till the start of the end game. It is a pitty that DeepMind/Google is going to decommission AlphaGo and not making it available anymore to be played against.
PeddlingThis morning, three others and I spend about two hours traveling through Giethoorn by boat and using poles to push the boat forward. I did some reading and also slept for an hour. In the afternoon, the couple who arrived peddling was teaching others to peddle on their boards. I also gave it a try, being a little nervous because I did not have a spare pair of trousers in case I would fall in the water. At my first attempt to stand up-right, I dropped to my knees immediately as I felt unstable. I was instructed to place my feet a little further apart. On the second try, it worked a little better. I had to take a few deep breaths to calm my hardrate and stop my legs from trembling. When I started peddling, I noticed that the trembling returned, but slowly it got a little better. When a speedboat was approaching, I dropped to my knees before the waves arrived. I guess, I would need another hour to become comfortable enough to go on a longer trip.
reading the book The Boxer and the Goal Keeper: Sartre Versus Camus by Andy Martin, which I started reading on May 19. I bought the book on Wednesday, March 9, 2016. I found this a well written and interesting to read book. The only problem I had with it, and which I have encountered with other biographic books, is the in some places thematic approach. The book definitely made me interested in reading more from and about both Sartre and Camus.
KraggehuisAt the end of the afternoon, I arrived in Giethoorn. I had wait some time before the boat arrived to bring me to the Kraggehuis, a group accomodation in the middle of the lake. When the boat arrived, I had to wait a little more, because there were some last minute shoppings to be done. The boat had no engine, so we needed to used long poles to push is forward, because the water is less than a meter deep. Some people were playing Go outside when we arrived at the island. Dinner was served around eight in the evening, just after a couple arrived peddling on 13'2 Explorer boards. I looked at several Go games being played by others.
GOGBOT caféThis evening, I went to the GOGBOT café event at Tetem art space. There were presentations by:
Tuesday, June 6, 2017
BookAt 17:54, I bought the book AKI Eindexamencatalogus studiejaar 1987/1988 written in Dutch and published by Instituut voor Hoger Beeldend Kunstonderwijs in 1988 from charity shop Het Goed for € 3.95.
Monday, May 29, 2017
Bookshops in UtrechtFrom the railway station, I walked through the streets Voor Clarenburg and Mariastraat to bookshop De Wijze Kater. I just paid a short visit and only looked at some singing bowls. Next I went to bookshop Steven Sterk and spend some time looking around. At last, I visited Broese Boekverkopers. There again, I only looked around.
Trip to China 2010
-- contact -- Frans
My life as a hacker
The Art of Programming
HTML to LaTeX
eXtreme Programming Programs Hamilton cycles