Yesterday and today, I made a new version of the
program for generating Fractal Jigsaw
puzzles. I added the option -space, which allows you to specify
the space between the pieces. Most DIY-laser cutters make a very narrow cut,
which means that if you make a puzzle, the pieces will fit very tightly
together. To avoid this, the idea is to make two cuts and throw away the
material in between. For this, I had to write a new algorithm. The old
algorithm (still used when no value or a non-positive value for -space
is used) would generate lines from top to down. The new algorithm generate a
cut for each piece. For this reason the algorithm needs to track the sides of
the pieces. This method can also be used to cut the border by following the
(in)side of the border. Because now these are cut one-by-one, all the corners
will be round, and the shape of the pieces and border is a little different
from the single line cut. I am thinking about adding the option -round
to implement this same shape in the single cut algorithm.
At 10:39, I bought the book FastFurniture, Multiples and Other
Productions written by P.J.H. Kockelkoren in English and Dutch, and
published by Uitgeverij AKI/ArtEZ in January 2007,
ISBN:9789073025103, from charity shop Het Goed
for € 1.50.
This evening at TkkrLab, I worked on putting
together my new HyperBrain Machine, consisting of an old pair of safety
glasses, a NeoPixel LED strip and a NodeMCU. Martijn, another member made a wooden box for the NodeMCU
module and he also helped me with repairing the NodeMCU. I wanted to feed the
LED strip from the USB voltage, but the VIN pin has a diode, after we removed
it and short circuit it, it turned out that the connection from the USB to the
VIN pin was broken (probably burned out under the load of the LED strip). I
soldered a thin wire to repair the connection. And then it did work with some
example program that came with the AdaFruit NeoPixel Arduino library. Now I still have to write my own
program before Thursday evening when GOGBOT starts (or while I am there,
because we have decided to just do our own things).
Around 10:14, I saw pieces of the shell of a chestnut on the bicycle path. I
stopped and found the chestnut that was inside it. I took it home and placed
it in a pot in the garden and see what will happen.
This afternoon and evening, I was with TkkrLab at GOGBOT. I wrote
a program for the Hyperbrain Machine
and walked around with it for some time, looking at the other projects. I used
the questionair machine by Wiebe Audenaers
about the Trolley
problem with respect to AI. It printed a ticket with the result of my
answers and a QR-code of a link to a website explaining it. in the evening, I also saw part of the
robot pop-band Compressorhead that performed on the main stage.
GOGBOT: Day 2
Again, I spend the afternoon and evening at GOGBOT, most of the time in the TkkrLab
area. We used the laser-cutter, to cut a piano fractal
puzzle. It turned out, that the 'piece' consisting of the space in between
the pieces and the border, was most interesting. The found the space between
the pieces a little too much. I also walked around for some time to look at all
the other things. The things I found noteworthy are (in the order I saw them):
In the evening, there were some interesting experiments with throwing
dry ice in a pan with
molted sugar (with a temperature higher than 100°C).
Bits, bots and brains
This afternoon, I visited the exhibition
Bits, bots and brains at Tetem art
space with a visiting friend. I did like the music being played.
With a visiting friend, I went to Rijksmuseum
Twenthe. We first went to see the exhibition
Lief en Leed (Joy and Sorrow), which is about family portraits from wealthy families
from the 17th and 18th century that are not totally factual and often hide some
sad truth. Next we went to see Bernard Heesen and the folly of the 19th century. We watched a short
documentary about Heesen make one of his glass art works. This made me
appreciate the exhibition much more than the last
time I saw it. Next we also watched the other exhibitions. Of course, I saw
Falaises près de Pourville from 1882 by Claude Monet.
With a visiting friend, I went to Utrecht. We first looked around at the
travel bookshop Interglobe. Next we paid a short visit to Radio Centrum,
an electronics shop that I visited for the first time around 1974. (The
earliest record in my diary of a visit to the shop is of Saturday, March 27, 1976.) This is very probably the last visit, because
they were having a closing down sale. I looked if I could find something
interesting to build, but I could not decided on anything to buy. Next we
went to Bookshop Broese. I did not buy
any book, but my friend did. They were closing down their second hand books
section. On our way to Dom Tower, we paid a short visit to the bookshop Steven Sterk. We
went to visit the monastery garden, where there was (it seems) a reception for
a wedding of two women. We also went inside the church were there we listened
to the practice of Missa Assumpta est Maria by Marc-Antoine Charpentier. We also visited the The Oude Hortus. We saw the Sequoia Giganteum, the Ginkgo Biloba (one of
the oldest outside of Japan), and the Victoria Amazonica.
We visited Amsterdam today. We parked at the Olympic Statium and took the tram
to the center. We had to change near Het
Martyrium and went in to have a short look. We went to Rijksmuseum. We only saw a small part of the museum. The works I found
worth mentioning are:
- Portret van Lizzy Ansingh, Thérèse Schwartze, 1902.
- Rue Nôtre-Dame, Parijs, Johan Barthold Jongkind, 1866.
- La Corniche bij Monaco, Claude Monet, 1884.
- Strand by eb, Charles-François Daubigny.
- Bosgezicht nabij Barbizon, Johan Hendruk Weissenbruch, 1900.
- Koe aan de slootkant, Willem Maris, 1885-1986.
- Kinderen der zee, Jozef Israës, 1872.
- Portret van Jenny Karmelingh Onnes, Menso Karmelingh Onnes, 1888.
- De Singelbrug bij de Paleisstraat in Amsterdam,
George Hendrik Breitner, 1896 and 1898.
- Gezicht op het Oostenpark in Amsterdam, George Hendrik Breitner,
- De Voorstraatshaven in Dortdrecht, George Hendrik Breitner, 1896 and
- Tuin met vlinders, Vincent van Gogh, 1890.
- Zelfportret, Vincent van Gogh, 1887.
- Portret van een man met één oog, Vincent van Gogh,
- Toevalsobjectivering, Herman de Vries, 1967.
- Schotelreliëf, Jan Schoonhoven, 1963.
- Reliëf met segment, Ad Dekkers, 1967.
- Variatie op cirkels IV, Ad Dekkers, 1965-1967.
We walked along the cannals to the Dam Square, and from there to Booshop Scheltema. At At 16:23, I bought the following tow books:
- Valerie Solanas written by Breanne Fahs in English and published by
The Feminist Press at CUNY in 2014, ISBN:9781558618497, for € 9.95.
- Warhol in China written by Michael Frahm, Tony Godfrey, Andy Warhol,
Ai Weiwei, Philip Tinari, and Jeffrey Deitch, written in English and
Chinese, and published by Hatje Cantz on Friday, February 28, 2014,
ISBN:9783775736626, € 22.50.
This evening, I finished a first
version of my program for generating the elments of a mathematical group from a generation expression. I have tested this on
some of the generation expressions given on Small finite groups and Cayley tables. It seems that the algorithm works
for most of them. With some of the generation expressions, the algorithm found
shorter identity sequences than the ones given in the generation expression.
Maybe these generation expressions are incorrect.
We went to the Kröller-Müller Museum. (At the entrance of the park, the
visiting friend bought a map for me.) We first went
into the Van Gogh wing and later walked through the sculpture garden. The works
I found worth mentioning are:
My result of taking the
free personality test from The SAPA
- Au café, Auguste Renoir, 1877.
- Le clown musical, Auguste Renoir, 1868.
- Mata Hari, Isaac Israels, 1916.
- Fabrieksmeisjes, George Breitner, 1898.
- De windstoot, George Breitner, c1900.
- Entrée du port de Marseille, Paul Signac, 1898.
- Port-en-Bessin, La Valleuse, Paul Signac, 1884.
- Straat met bomen, Kalmthout, Henry van de Velde, 1990-1991.
- Roze perzikbomen, Vincent van Gogh, March 30, 1888.
- Herfstlandschap, Vincent van Gogh, November 1885.
- Meisje in het bos, Vincent van Gogh, August 1882.
- Populierenlaan bij zonsondergang, Vincent van Gogh, October 1884.
- De aardappeleters, Vincent van Gogh, April - May 1885.
- La Berceuse, Vincent van Gogh, December 1988 - January 1889.
- Vier uitgebloeide zonnebloemen, Vincent van Gogh, August - October 1887.
- Treurende oude man, Vincent van Gogh, May 1890.
- Het ommuurde korenveld met opkomende zon, Vincent van Gogh, May 1889.
- De barmhartige Samaritaan, Vincent van Gogh, May 1890.
- Moulin de la Galette, Vincent van Gogh, October 1886.
- Mand met citroenen en fles, Vincent van Gogh, May 1988.
- Caféterras bij nacht, Vincent van Gogh, about September 16, 1888.
- Korenschelf onder wolkenlucht, Vincent van Gogh, June 12-13, 1888.
- Landweg in de Provence bij nacht, Vincent van Gogh, May 12-15, 1990.
- Cipressen met twee figuren, Vincent van Gogh, June 1889 - February 1990.
- Olijfgaard, Vincent van Gogh, June 1889.
- Brug te Aries, Vincent van Gogh, March 1888.
- Compositie met rood, geel, blauw, Piet Mondraan, .
- Compositie met raster 5: ruit, compositie met kleuren, Piet Mondraan, 1919.
- Compositie met raster 6: ruit, compositie met kleuren, Piet Mondraan, 1919.
- Compositie in kleur A, Piet Mondraan, 1917.
- Zelfportret, Charley Toorop, 1953-1954
- Compositie in kleur b, Piet Mondraan, 1917.
- Tableau no. 1, Piet Mondraan, 1913.
- Endegeest, Floris Verster, 1893.
- En juillet-avant midi of Le vergen, Théo van Rysselbergh, 1890.
- Le 'Per-kiridy' à marée haute, Théo van Rysselbergh, 1889.
- L'Arc-en-ciel, Pntoise, Camillo Pissarro, 1877.
- Février, soleil levant, Bazincourt, Camillo Pissarro, 1893.
- La Briquetterie, Alfred Sisley, 1880.
- Il vient de loin, Paul Joseph Constantin Gabriël, about 1887.
- Cavallo e cavaliere, Marino Marini, 1951-1955
- Needle tower, Kenneth Snelson, 1968.
- Accu voor vijf vingers, Jan van Munster, 1995,
- Femme accroupie, Auguste Rodin.
With respect to the big five personality traits, my percentile ranks according to the test are: 16 for Extraversion, 66 for
Openness, 42 for Conscientiousness, 54 for Neuroticism, and 50 for
Agreeableness. It seems I do not fit in any of the four personality types
identified in the paper A robust data-driven approach identifies four personality types across four
large data sets. I also scored 99 on cognition, but that was only based on
only eight questions and consisted of some tests that I have done many times
and that I am known to be good at. There were also no time constraints and I
took time to figure out the answers.
Dutch Kabuki Day
Andy and I went to the Dutch Kabuki day. In the morning
there was a general meeting with some presentation. Connie Strumpel gave a
short introduction with recent developments. Next, a presentation of the use of
growth hormone. About 75% of children with Kabuki Syndrome have a short
stature, which develops after they are born. High frequence in KMT2D (MLL2)
mutation. The cause of the short stature is unknown. In the literature there
is but one growth curve available. Based on questionairs in the Netherlands,
growth curves have been made. There is also a clear tendancy of obesitas,
especially with the girls starting from around six years, The average length
of adult males is 161cm and females is 149cm. A growth spurt has not been
observed. Also the development of the puberty is not clear (due to lack of
information). Five of the 20 individuals in the study were eligable for
growth hormone therapy. At the start of the study the average standard
deviation of the length was -2.4. After two years, the average standard
deviation had increased with 1.1. This is a good result. If the growth hormone
thrapy is stopped after one year, the standard deviation drops again. This
suggest that the therapy should be continues after the desired effect has been
achieved. There are also clear indications that the metabolic rate of children
with Kabuki Syndrome is lower than normal. Growth hormone therapy increases
this to almost normal. The low metabolic rate could also explain the obesitas.
The hormone therapy has not been found to have any averse effects. With respect
to hypermobility. With Kabuki Syndrome there is a higher hypermobility with
both boys and girls about the same. It seems that this is stronger with some
joints. The growth hormone therapy also has a positive effect on hypermobility
especially with those joints where it was worse. It seems that the therapy has
a positive effect on the connective tissue.
The second presentation was about genes and behaviour. Neuro psychology covers
more than just intelligence. It also has to do with memory and executive
functions, for example. These can be even further divided. Social cognition is
another important area: recognizing emotions. The research program included two
different rare syndromes and the general group of people with a mental
handicap. One of the research question was if there are specific problem areas
with respect to Kabuki Syndrome. The study involved 13 female and 15 male
individuals. Not everyone was able to do all the tests. The conclusion is that
the development age is lower and stops earlier. With respect to intelligence
there was a great variation. Individuals were worse with remembering visual
information, while they are better with verbal information. This also has an
effect on the executive functions. In the behaviour area there were problems
with attention or with social interaction, but these seems not worse compared
with similar syndromes and could be explained with lower development age.
Auditive memory is good. There are behaviour problems but these are not very
specific. (To me it seems that this findings are compatible with the delayed
In the afternoon, there was a short documentary about one of the young women
with Kabuki Syndrome. There was also a presentation an organisation dealing
about rare diseases and conditions. Rare means less in 1 in 2000. Often it
takes a long time before a rare disease or condition is diagnosed. About one
in seventeen people have a rare disease or condition. There are now 400 expert
centres in the various academical hospitals in the Netherlands. A GP sees most
rare disease or conditions at most once in their practice. They now want to
combine all information with respect ot Kabiki Syndrome into one document,
both for medical specialists as for the parents.
Computers old and new
I have decided to do some system adminstration work on my old and new
computers. Yesterday, I bought a Seagate
Expansion+ 2TB external harddrive to backup the contents of some
I first started lixia. I discovered
that the new external harddrive still needed to be formatted. When I removed
it lixia rebooted. I started copying the D drive, but it looked like
the PC locked-up, and I switched it off after some time. I tried it again with
a batch file with XCOPY commands. That seemed to work better.
I tried to start up the OptiPlex 755, but it
not seem to work. The attached monitor did not register a VGA signal. I opened
it to see what was inside. (Later on the day, I removed the clock battery, and
put it into johan to resolve the
issue with the internal clock.) Next, I switched on the Lenovo Thinkcentre Edge72 to discover that it had a fresh install of
Windows 7. But I guess, I do not have a valid licence key, meaning that I can
only use it while not connecting to the internet. Anyway, I had promised that
I would install Linux on it. I tried to install Debian 9 with a USB stick
created with UNetBootin,
but after the installation, the BIOS reported that no operating system was
found. I tried some other tools for putting an ISO image on an USB stick, but
in the end I used the Cygwin dd command to copy the debian-9.5.0-amd64-netinst.iso image.
When I started the install, I did not get the question to choose for the
UEFI install as I did the first time. However, the second time, I did
get the option to install GRUB. And this time, the installed worked.
At TkkrLab, I first helped someone with the
first lesson of our Arduino course
(in Dutch). Next, I worked a little on a program for the Irregular Chocolate Bar problem. When I was about to leave, someone
showed the clock display he had developed for the 17 by 10 LED Matrix in the
space. Someone else suggested that more people should start writing software
for the LED Matrix. I decided to give it a try, and with some searching on the
internet, hacked a small C++ program together. First thing I did, was setting
the colour #FFAA5E on all the LED's. I plan on writing a small C++ library for
controlling the LED Matrix.
This afternoon, I went to the TkkrLab
space to compile and test the first version
of a program to use the LED Matrix in the space. The LED Matrix is controlled
through (a slightly relaxed version of) the the Art-Net protocol. I am thinking about at least add another class
between the classes UDPSocket and LEDMatrix to implement the
Art-Net protocol, as there are some other devices in the space that can be
controlled with the Art-Net protocol.
Escape room: The Time Machine
As part of my farewell party, we had some dinner in the city and also played
some escape rooms. Together with five others, I played The Time Machine
escape room. For all of us, it was the first time we did it. We did not make
use of any hints, but did get one hint, because we did not realize that the
piece of paper behind which a key was hidden, actually was an envelop with
instructions inside. We did not finish the escape room within the set time
limit of an hour. We failed to complete the last three puzzles. But we still
were proud of our achievement, because it was the first time and we finished
some of the puzzles rather quick according to the game master. We also had a
lot of fun and we worked as a team, I think. As a farewell gift, I was
given a framed poster which contained a compination of a picture of myself
and the work CONW54 TGCOL 1 by Peter Struycken. The
poster was made by one of colleagues.
Two years ago, I got a new pair of glasses to be used behind the computer. Just
like everyone else, I suffer from presbyopia due to a reduced ability of my eyes to accomodate because I am getting older. I have been near-sighted all my life with a high myopia of about 8 dioptre. It is easier to work with dioptre when calculating the effect
of combining lenses (at short distances), than to work with focal distances.
For a long time, I had been able to correct my presbyopia by moving my glasses
a little away from my eyes by placing them at a lower point at my nose. But at
some point, it required to tilt my head backwards to look at a computer
monitor, which was causing strain. The pair of glasses I got two years ago, had
a correction of +0.75 dioptre with respect to my standard prescription.
Although, these glasses were intended to be used behind the computer, I noticed
that I could also use them for biking around and I began to use them all the
time. While riding a car, I often used a pair of sunglasses with no correction.
Only when going to the movies, I used my old glasses. I got the impression that
my nearsightness had become less.
In the past half year, I noticed that I was moving my glasses down my nose
again. So about a month ago, I went back to have my eyes examined. It turned
out that my nearsightness had remain the same. The optometrist who checked my
eyes, suggested that I should have a correction of +1 dioptre. Because of the
small difference and the prices of the glasses, I decided to give it some
second thoughts, also thinking that maybe I was confused about how often I
lowered my glasses. On Friday, September 21, I went back to have a second look.
I talked with another optimetrist who gave me a pair of test glasses and after
some experimentation we agreed on correction of +1.25 dioptre. When I suggested
that we also should test +1.5 dioptre, I got the remark that I should not make
my eyes lazy. Although I tried to keep the test glasses as close as possible
to my eyes, I still had some doubts about the measurement method, because I
know that moving my glasses but a few mm, will have a dramatic effect on the
focal distances and the correction lenses where the furthers away from my eyes.
Yesterday, I went to collect the glasses. I already noticed that I was still
able to see sharp at quite some distance. In the evening, with poorer lighting
conditions, I suddenly noticed that I was wearing my glasses in the same way
as before. It seems that the extra +0.5 dioptre did not have much effect at
all. In the evening, your pupils open further and by doing so reduce the range
at which you can see sharp. I started looking at some websites for more
information and also started to some calculations. At my age, the average
correction for reading glasses is +2.25 dioptre. The prescription is measured
at about a distance of about 10m, which is equal to 0.1 dioptre. For reading
at 30cm, which equals to about 3 dioptre, you need a correction of 3.1 if you
would have no accomodation at all. And indeed, at a high age, the correction
for reading glasses is +3 dioptre. When I work behind the computer, the
distance is between 60 and 70 cm. With my new glasses at daylight, I need
about 110 cm to see sharp. When at that distance, I put my pair of glasses
the furthers away from my eyes, and then test at which distance, I can still
see sharp, I can get as close as 55 cm. This is equivalent with about 0.9
dioptre accomodation, which is about the average value on my age. I have done
some calculations, and it seems that with a correction at +2.25 dioptre, my
range becomes 53 cm to 99 cm with an ideal looking distance of 68 cm.
This months interesting links
| August 2018
| October 2018