Man kills child at school
Around 11:15 this morning, the 8-year-old boy Jesse
Dingemans was killed in his school
Klim-Op in the
town of Hoogerheide. At first it was reported that he
was killed by his father. Later a 22-year-old man was
arrested and it became known that his father is the
manager of the office of the Rabobank in Halsteren. This crime was reported by
CNN. None of the children witnessed the killing
because Jesse had gone back to his class room to fetch
something after he got permission from his teacher while
the were working elsewhere in the school.
Yesterday, I read on some page, that according to
Noam D. Elkies
the number of domino tilings for an MxN rectangle is 2^(M*N/2) times the product of
( cos^2(m*pi/(M+1)) + cos^2(n*pi/(N+1)) )^(1/4)
over all m,n in the range 0<m<M+1, 0<n<N+1.
I found this quite a surprising result, and this evening,
I wrote a small program to verify the
result, and it seems that the result is correct.
Some years ago I calculated the number of domino tilings
and the results can be found here.
What is it?
Today, I came across the image shown on the right. I found it on
the web site of Nanophotonics.
At first I thought it was a kind of lamp, and I think that is what most
people think it is. But it is actually a wide angle camera.
This afternoon, I was biking behind Arjan and Erik from
the Dutch "Beauty and the Nerd", when I went to
a meeting in Hengelo. Most of the time they were biking
behind each other. One of them was wearing a string in his
hair. They were biking a little faster than I. I lost
sight of them when they just past through a green light
at the first traffic lights in Hengelo. I guess they returned
home from the university. This evening, we watched the
Arjan and Erik
This evening, Annabel and I, watched part of
the video chat of Arjan and Erik which
they had yesterday. It must have been Arjan
biking behind Erik when I saw them, because Arjan is the one
still having a string in his hair. During the chat they tell that
they live on the Campus of the University of Twente in Enschede.
It is possible that yesterday they were on their way to the
studio of RTV Oost.
This evening, I went to the university to play Go.
I had taken a board and stones with me. I had to wait some time
before Araldo arrived. When a little later, Taco arrived, I let
them play on my board, because I still wanted to wait for Ton.
Not much later Rudi arrived and we decided to play, and quite if
Ton would arrive. But Ton did not come. Edze did come and he first
watched Araldo and Taco for some time, and then watched us. I had
gotten nine stones ahead of Rudi and in the end I lost with 39 points.
There are indications that Li-Xia is
suffering from Early-onset
Alzheimer's Disease. Earlier this year she started
to have problems with her memory and I advised her to seek some
information on this. On June 1, someone came to test her,
and we both were a little surprised by how bad she performed. She
also did not score very well on the Visual Association Test.
Later, I discovered that this is strong early indicator for
Alzheimer but also occurs with people with a depression. 0n
October 9, we went to see a neurologist, and Li-Xia was given an
a psychological exam (on October 19), a lumbar puncture was performed
to examine her cerebrospinal fluid (on November 7), and a MRI
was performed on her hear (on November 10). Today, we went back for
the results. On one hand, Li-Xia was quite happy that there is now
an explaination for her problems. For the rest she seems to accept
the situation quite calm, realizing that there is not much to do
about it. The neurologist prescribed some Reminyl.
(Dutch medicine information for Reminyl.)
In the evening, I showed Li-Xia
information folder in Chinese. At the moment she feels quite
Annabel getting taller
When Annabel came downstairs this morning,
she remarked that felt that she had become taller, and asked if I could
measure her. She is now just one centimeter shorter than her mother.
It looks she grew two centimeters in the past month. But maybe she is
just taller because we measure her length in the morning, and the last
time in the evening. But without doubth she is getting taller.
Today, Li-Xia started with the Reminyl. Till
noon she felt okay, but during the day she felt worse and worse.
Around eight o'clock in the evening she even had to vomit. She stayed
in bed from till about four o'clock in the afternoon and did not eat
When I came home from the city this afternoon around three o'clock
there was a beautifull complete double rainbow visible. The others
also saw it, and Annabel
and I took some pictures.
Formation of a coalition
In our political multi-party system, parties have to form
a coalition in order to form a government. The result of
the last election are such that the formation of a coalition
is going to be difficult. Yesterday, it became known that
the most obvious coalition did not work out. This means that
a second round will be started to determine what is the
next most likely coalition to be investigated. This is a
rather slow process in realizing a coalition. I wonder
whether there does not exist a more mathematical method
to arrive at a coalition. Maybe there should be some voting.
For example, one could use the procedure where every party
expresses their favours for a certain coalition, and than
based on the number of votes they got, one can calculate
which is the coalition that has the largest support among
This morning, watched music video
by Lasse Gjertsen.
Only 22 years old. Great music, great performance!
He has created some more great video's
This evening, Annabel and I went
to the university to play Go. When we
arrived, Ton and Juri were already there. I had brought a
playing set with me, and invited Ton for a game. It has been
a very long time, that I did not play against him. Soon some
others arrived, but nobody with boards and stones. Finally,
someone borrowed a set from Fanaat, and decided to play Ren-Go with seven persons,
Annabel being one of them. My game with Ton started good, but
later on I made a mess of it and finally decided to resign,
because my position was hopeless.
I finally feel some motivation to learn Chinese, because of
the possibility of Li-Xia losing her ability to speak English
and Dutch in the coming years. I downloaded many MP3 files
from Chinese in 10 Minutes a Day, and listen to them while
I did the dishes. Maybe I could also download the MP3 files
from Conversational Mandarin Chinese Online.
Annabel has been busy making
Christmas cards for the children of her class. She asked
me to scan a drawing of a pinguin that she had made on
the basis of some sample.
Finals of the Beauty and the Nerd
This evening, we watched the finals of the Dutch
"Beauty and the Nerd". This morning, I already read
on the website of a local newspaper who are going to
win. This is because tonights broadcast is a repeat
of the broadcast of yesterday evening, which we did
not watch. Erik and Racheal won the
contest. They won € 25.000 and a trip.
Intimate conversation between Beauty and Nerd:
Beauty: So you did masturbate?
Nerd: (shy) Yes.
Beauty: And what did you think about?
Beauty: About mathematical formuleas or such?
Nerd: Yes, beautiful round numbers.
It was a busy evening. First I had to bring Andy to his Christmas party on school. Next I had to
bring Annabel to a church where
her church celebrated Christmas, and from there I went to
get Andy. Then arround eight o'clock I got Annabel from the
church and from there I drove to the university to
play Go. When we arrived, Ton and
Judi were playing on a set that Juri had brought with him.
They told us that Araldo also went to get a set. Not much
later the others arrived and Annabel and I ended up being
left over. We first played a 13x13 game, which I lost.
Then we played a 19x19 game, which I won because I killed
one group. Because Ton and Juri also finished their game
around half past nine, Ton invited me for a game. We played
a light game till about twenty past ten. He won, because I
lost one group, but otherwise I would have won clearly.
Chinees Wooden Puzzle
Today, we went to visit my mother and I brought the
Chinese Wooden Puzzle with me.
I showed it to a nephew. After he filled it with all pieces
of the same colour matching each ohter, he then went on
to fill such that no two pieces with the same colour
touch each other. He came quite far, but his mother had
to help him to find a solution. Later, I realized that
it would be rather easy to find many solutions for this
puzzle, when I realized that it must be easy to pick
combinations from 3 by 10 solutions
to fill the 15 by 10 square such that no two pieces with
the same colour touch each other.
When I was playing with the puzzle, I asked myself how
many ways there exists to put the six pieces consisting
of one of each colour except the colours white and pink
inside a five by five square. I quickly found a solution
but had a hard time finding another one. My nephew also
gave it a try, but could also not find another solution.
I told him that at home I had a program with which I
easily could check this. When I tried it at home, it did
only find the eight equivalent solutions. So there is
only one way to put these together, and that is:
Chinese Wooden Puzzle
In the past days, I wrote a program to count the number
of solution for Chinese Wooden Puzzle
using the 3 by 10 solutions
in such a way that no two pieces of the same colour are
touching. The total number of unique solutions is 37,939,697,213,728.
That means that about 1.28% of all the possible solutions
that can be made, have no pieces of the same colour touching
I also worked on extending the program to include the
5 by 6 solutions, but this
proved to be much harder, because there are so many more
solutions, that the program did not terminate within
Chinese Wooden Puzzle
This morning, I continued working on the program. Because
there are 874 unique 5 by 6 solutions,
this means that there are 12222016 non-unique ways to put two
solutions on top of each other to form a 6 by 10 solution.
Of these 6609208 do not have pieces of the same colour touching
each other. Luckily, these only result in 68054 different
During the day, I discovered that the greatest performance
problem was in the collection of coloured columns that can
occur. I replaced the linear list by a tree structure. That
gave a great boost, but I estimate that the program still will
take about 66 hours to finish the complete computation.
Visiting Ton, Sara, and Titus
This evening, Annabel and I
visited Ton and his children Sara and Titus. We also
brought the Chinese
Wooden Puzzle with us. Both Titus and Sara solved
it. And Annabel also solved it one more time within a
few minutes, and without any back-tracking. Ton and
I played two games of Go. I resigned
early during the first game, because I lost quite a big
group of stones. During the end of the middle game of
the second game, it seems I was going to lose again.
I made some "desperate" move to reduce his territory.
And then after some more moves, Ton got into some big
trouble and I managed to capture a group of his, after
which he resigened. Annabel also played two games. One
against Titus, which she lost by a few points, and one
against Sara, which she won after Sara resigned. Ton
guessed that they are all around 20 Kyu now. I am now
playing with a six stone advance against Ton. He too
has become stronger in the past year. I guess my strenght
is now around 14-15 Kyu. The children also played up
stairs in the attic which is a very large and nice
play room. Annabel built a house from blue foam bricks
with adhesive layer, which seems to be some kind of
waste product that Ton got from some company. Annabel
likes it very much.
Execution of Saddam Hussein
This morning, 4 o'clock in the morning, Saddam Hussein
was executed. Late Friday from his ranch in Texas, President
Bush from the U.S.A. said "it is
an important milestone on Iraq's course to becoming a
democracy that can govern, sustain and defend itself,
and be an ally in the war on terror."
This months interesting links
November 2006 |
January 2007 |