## I write, therefore I amWith 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. | ||||||||||||||||||||||||||||||||||||||

## Wednesday, August 26, 2015## PARR introductionOn page 39 ofThe Phenemenon of scale: The art of nanotechnolology it says about
PARR by WLFR: Begun in 1999, PARR is a
research project regarding 'nano-aesthetics': the creation of a form on the
smallest possible scale. For this project, a tiny imaginary universe of two
dimensions was created, with only three 'natural law s': There is a five by
four grid of positions, to give a possible twenty positions in total. Between
two neighbouring points (horizontally, vertically or diagonally) a connection
may, or may not, exist. It also displays nine PARR with seven points and
nine connections. In all nine all points are connected through connections
and there appear no (diagonal) crossing connections. Are these extra
requirements, not stated here explicitly?
I wondered how these are generated and thought about a JavaScript program to produce them. There are different strategies that can be used. First of all one could randomly generate place nine points, connect all the connections between them, see if there are eleven or more. In case there are eleven, remove some at random. Of course, this would lead to many disconnected drawings. One could use a random walk to generate the points, where locations already visited do not change. Either one could draw the connections of the walk and stop when there would be accidently more than eleven, and in case there are less when nine points are placed, see if some additional connections can be added to add up to eleven. This procedure could fail. Another method would be to generate random points, but take care that they have a neighbour in common with one of the already placed points and draw a connecting connection with this point. And after all points are placed add some additional connections
I wondered how many different PARR's there exist. I wrote the program PARR.cpp for counting them. This
program generates the PARR page. I first decided
to count the number of PARR's in which each pair of points that are neighbours,
have a connection, and allowing crossing diagonals. The total of this is
equal to 2 ## Monday, August 24, 2015## BookOn 11:31, I bought the bookThe Phenemenon of scale: The art of nanotechnolology from
charity shop Het Goed, which I had
seen last Friday, for € 1.00, including tip of 5 Euro cent.
## Sunday, August 23, 2015## Link## Saturday, August 22, 2015## SunsetThis afternoon, we visited TETEM art space. But before we arrived there, be biked along Studio Dertien and noticed that there was exhibition of Cheng Liang and Han Xi. We went in to have a look. In Tetem, we first watch a documentary about Safecast, which is about measuring radiation levels in Japan. Secondly, we looked atAlpha town and citizen sensing by Frededik de Wilde. Next we watched the exposition of the descendants of
Gerrit Jan van Heek (1837-1915). We especially liked one of the pictures of
Sophia Bijkerk. After Tetem, we biked to Concordia where we looked at the Cargo
exhibtion with works from Wessel
Vreeken, Erik Luchtenberg,
and Mark Bakema.
In the evening, we walked to the Helweg to see the sunset and took some
pictures, one of which is shown on the right.
## Friday, August 21, 2015## BooksAt 10:30, I bought the following three books from charity shop Het Goed:*Rijksmuseum Twenthe*by Josien Beltman, ISBN:9789055448272, for € 2.95, which on page 92 has a work by Peter Strucken.*aki akademie voor beeldende kunst 1996*, ISBN:9789075522051, for € 2.50.*You should be here! A book about Helsinki, second edition*by Tom Bulgaria (editor) for € 1.50 EUR.
The Phenemenon of scale: The art of nanotechnolology. On page 39,
it has some interesting patterns with dots connected with lines from the PARR
project by WLFR, a cooperation between
Taconis Stolk and Sietske Sips.
## Wednesday, August 19, 2015## ZomergoI attended Zomergo, a rather relaxed Go retreat, for one day together with a colleague. In the morning, I played one game of go with Elske. It was an interesting game. I won with just one and half point (including the 6½ komi). The final state of the board is shown on the right. Some stronger players made some remakrs about some moves that could have made the difference larger for me. In the afternoon, I helped with preparing the dinner. I also went outside and had a short look at the workshop and a real life game of RoboRally where water pistols were used for the shooting. I stir fried the mie for the dinner, which included various ingredients from the common wood pigeon: breast, wings, legs, heart and lung. For desert we had Eton mess with home made meringue and strawberries marinated in rum. Simply delicious.## Thursday, August 13, 2015## Havannah versus Hex (part 3)Today, I met with Ton, and I bought a Havannah board from him. We did not play Havannah (he is much stronger than me), but we played a game of Wings, a variant he invented. He also showed me Tetra-Hex (not sure about spelling) which is a connect all your stones variant of Hex which is played on a tetrahedron and where both players start with two stones on two of the four corners. If you can surround a stone of your opponent, you win the game, because your opponent will never be able to connect all her stones. He explained that connection games are only interesting if they have moves that are balanced with respect to the pie rule. We also compared the Hex database with the results presented on Computer Hex. We talked about the difference in complexity between the racing connection games and the non-racing games. I pointed out a remark that I found inMoHex 2.0: a pattern-based MCTS Hex player by S. Huang, B. Arneson,
R. Hayward, M. Mueller, and J. Pawlewicz, where it says:
By contrast, Timo Ewalds (private communication) found no improvement from
using probabilistic simulations in the Havannah program Castro, possibly because
any such improvement is overwhelmed by dynamic factors such as the
sudden-death threat from rings. This seems to indicate that the complexity
of Havannah, a racing game, is greater than Hex, a non-racing game where
always one of the players wins. But I said that it might be difficult to prove
that this complexity can be contributed to the racing property or has to do
with the sudden-death of rings. It might be that Havannah is a more interesting
game with respect to the properties described in Defining the Abstract. The master thesis Playing and Solving Havannah by Timo Ewalds contains an table about the state complexity of Havannah and
Hex (among others). In order of complexity the table contains the following
entries:
It appears that the size of the state space is strongly related to the number
of cells, and thus also with the complexity of the game.
Ewalds also writes: ## Monday, August 10, 2015## Rainbow at sunsetAt about 20:40, I noticed a rainbow when I looked outside on the street side of the house. I went outside to have a beter look, to see if I could make a photograph. I took my camera and went into the back garden. It was indeed a bright, double, round rainbow. I took several pictures, of which one is shown here on the right. I went out several times to see how long it lasted. It seemed to fade a little, but then around 21 it brighted up again. There was almost no rain, and at that time the sun was lighting up the clouds to the west and above from the underside. It also seemed as if the rainbow was in the clouds. Then again it began to fade and finally disappeared at the moment of the sunset at 20:09. (I noticed that it was getting darker earlier. Around this time of the year the sunset happens about two minutes earlier every day.) The picture also shows of the branches that are growing straight up from our magnolia. There are still some flowers in it. I have to prune it one of these days.## Friday, July 30, 2015## BookAt 13:43, I bought the bookZwerver by Johan Kelder from
bookshop Broekhuis for € 2.50.
## Wednesday, July 29, 2015## Havannah versus Hex (part 2)On July 18, I wrote about the complexity of Havannah versus Hex and said I would be working on a formalization of connection games. I made it a little broader, and wrote something on the formalization of abstract strategy games, which is actually a rewrite of a formalization of Havannah that I wrote some years ago. Yesterday, I foundHavannah and TwixT are PSPACE-complete. It was already known that
Hex is
PSPACE-complete.
According to the
Wikipedia page about game complexity, Havannah (size 10) has a higher
complexity than Hex (size 11). The numbers for Hex are from the article
Games solved: Now and in the future by
H.Jaap van den Herik, Jos W.H.M. Uiterwijk, and Jack van Rijswijck, which quotes the master thesis
Computer Hex: Are bees better than fruitflies? by Jack van
Rijswijck as it source. But after a quick scan through the thesis, I did not
find those numbers. Possibly they are taken from one of the referenced
articles. That Havannah (size 10) has a higher complexity than Hex (size 11)
could be the result of the fact that the first more than double the positions.
## Link## Saturday, July 25, 2015## Flowers in magnoliaI noticed some flowers in our magnolia. Many of them are in new branches. Here a picture of one of the flowers.## Friday, July 24, 2015## Links## Thursday, July 23, 2015## Institute for art historyToday, Peter Struycken and I visited the Netherlands Institute for Art History, also known asl RKD in Dutch. On forehand, we had made some requests about the materials we wanted to see, but soon it became clear that our small selection was far too large to be studied in one day. We started to work on the notes that Carel Blotkamp compiled for a catalogue of works, which, as it seems, was used for the 1974 exhibition. For this he send forms to all people owning works of Peter Struycken. Many of the works were know to me, but we also found some works that I had never seen before. Our greatest find was a panorama picture of P. Struycken - Structuur '67 exhibition on the back of which Peter had written all the Roman numbers of the works. This might resolve some of the riddles with respect to theStructuur '76 works. Peter also told me
about the research he is doing with respect to the use of colours starting
from the early Greeks in 500 BC.
## Monday, July 20, 2015## BookAt 13:10, I bought the bookOmgaan met kunst en natuur: Jo en Marlies Eyck
in Wijlre with text by Henk van Os and photographs by Kim Zwarts
from charity shop Het Goed for
€ 1.00 (including a € 0.05 tip). It contains pictures
from to works by Peter Struycken. Op page
22 there is a picture of Komputerstrukturen 2 under the title Computerstructuur zwart wit
4-69. This is the only published picture of this work that I know of.
There is a picture from the Struycken Structuur<->Elementen
exhibition on which this work is also visible. On pages 41 and 42 there are
pictures of Piet 5 under the
title Piet v.
## Saturday, July 18, 2015 |
## IntroductionDiariesAugust 2015 July 2015 June 2015 May 2015 April 2015 2015 2014 2013 Alzheimer's Disease Trip to China 2010 -- contact -- ## FamilyFransLi-Xia Annabel Andy Honeymoon Friends Others Pictures
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