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The temperature at Twenthe Airport has gone up to
13.5° Celsius, which breaks the previous record of 12.9° on this date
I got a 2Gbyte DDR3
SDRAM memory module from a fellow TkkrLab member and installed it in FJF2 following the YouTube video How to upgrade ram of Acer Aspire One D270. Easy! Do it yourself. I ran
some memory test to check the memory module before closing it. Reconnecting the
keyboard (twice) was the hardest part.
Paintings and such
Today, we spend some time cleaning the former home of my mother now that we are
in the process of selling the house. I took some paintings and objecs with me.
- Painting of a brook between trees, signed with 'H Kooy'.
- Still life paiting with fan.
- Painting of a bridge by a brother of my mother.
- Print Stadhuis Woerden 48/50I in frame.
- Framed picture Woerden: R.K.kerk en kasteel vanaf de toren Petruskerk.
- Cupper bowl with fish design.
- Print of Chinese ink painting with proverb sealed in some plastic.
- Bredemijer teapot.
- Two wooden egg cups.
- Package with ten pairs of bamboe shopsticks. Made in Taiwan.
- Fan from China.
- Iron on beads figure made by Annabel.
- Pen in the form of an injection tube.
- Extension cord.
- Some spices.
- Glass marble that I started to carry in my pocket.
I have been looking at the Tropy application
to see if I could use it for my research on Peter Struycken. It has some interesting features. It allows you organize
your images and allows you to add meta data and notes to these, including
selections of them. You can export the data as JSON and the notes are stored with a subset of HTML, which makes it possible to parse them. I want to extract data from
the images and have a way to relate, to correlate, and to condens them into
well established and supported facts. I also want to go from the facts back to
the data and the images they are based on. It seems that Tropy does not support
this. This afternoon, I discovered that it is possible to define templates
and base these on all kinds ontologies. I had some look at Linked Open Vocabularies and the GND ontology. These are based on Resource Description Framework. (On Hacker News there was some discussion about the semantic web.) I find this model a little limited and rather
cumbersome to work with. I thinking about representing the data in the images
with (nested) bullet lists in the notes and write some software to extract
2-state 4-color BLB
Last Wednesday, I read the blog Another New Record in Self-Cleaning Turing Machines, which is about a
new record breaking 2-state 4-color Turing Machine that is a Blanking Beaver, a kind of Busy Beaver. In the past two days, I have been trying to analyze it. This
evening, I found that it calculates the following Collatz like sequence:
n = 1; m = 1;
if ((n % 2) == 1)
if (m == 2)
n = 1;
n = 2 + 5 * (n + m) / 2;
m = 1;
n = 1 + 5 * n / 2;
The steps it took me to find this can be found in this
program. I started with an interpretting implementation for the Turing
machine using a compressed representation of the tape. The idea that in case
a number of cells are given the same 'colour' (symbol) to represent it as a
single cell with a number representing the count. The implementation is found
in the function interpretter. I ran this to get an idea of the
patterns that occured. At one point, I replaced the count (in the printout)
by a star character and discovered some repeating patterns. I decided to
write a version where the turing machine is hard code. See the function
hard_coded1. At one point, I made it print out the transitions from
state with colour under the head to next state and next colour under the head.
This showed that there were only a limited number of transitions. I used this
to construct the function hard_coded2 where they are shown in the
comments. I added labels for all state-colour combinations and a goto
statements for the transistions. In the function hard_coded3 I
reordered the statements such that state-colour combinations that often
occured to follow each other appeared below each other. I also added
while-loops for repeating state-colour combinations, which I rewrote in a
more compact form. (The while-loops can be found as comments in the code.)
This resulted in less output to be printed, but I took care that the lines in
the input still matched those generated with the earlier functions, to make
sure I had not introduced errors. I studied the output and noticed some
repeating patterns. This lead to the implementation of hard_coded4
function that tries to reimplement the behaviour starting from the 'A'-state,
'0'-colour combination. I already had noticed that there was a slight
difference depending on the number of ones on the left tape were odd or even.
(It took me some effort to get the number of intermediates steps calculated
correctly.) However, it did not result in the expected cleaning of the tape.
This lead to the development of the function hard_coded5 which does
not make a difference between whether the number of ones is odd or even, but
stops a little earlier. Now it did produce the expected cleaning of the tape
(not exactly). Through analyzing the output produced by this function, I
wrote the calc function, which is also shown above. The calculation
of the n variable is derived from the code of hard_coded5 and
the calculation of the m variable is based on analyzes of the output.
It is since last year September 2 that Conny and I went looking for border poles.
This afternoon, we continued our search. We were surprised to find several
border poles that we missed last year as they were clearly visible now. For
sure the amount of overgrowth is much less than in the four months ago. (I had
entered the location of the border poles we wanted to find in a GPX file and
unloaded it to my Galaxy Tab 3
tablet.) We encountered the following border poles:
- At 14:14, pole 25.
- At 14:21, pole 24-II.
- At 14:28, pole 26 (again).
- At 14:48, pole 26-V.
- At 14:54, pole 27 (again).
- At 14:58, pole 28.
- At 15:04, pole 29 (again).
- At 15:08, pole 30.
- At 15:13, pole 31 (again).
- At 15:15, pole 31-I (again).
- At 15:21, pole 31-II.
- At 15:25, pole 31-III.
Last Saturday, the lock-down with respect to non-essential shops came to an
end. This morning, I could not resist my urge to visit charity shop Het Goed on my way to the office. At 10:10, I bought the
- De Pythagoras Code: het beste uit een halve eeuw wiskunde voor
liefhebbers written by Alex van den Brandhof and A.J. Brandhof in
Dutch and published by Bert Bakker in 2011,
ISBN:9789035136465, for € 4.05.
- Architektur der Welt: Maya, Guatemala, Honduras, Yukatan, Volume 8
written by Henri Stierlin in German and published by Taschen in 1964 for
- Architektur der Welt: Das alte Mexiko, Volume 2 written by
Henri Stierlin written in German and published by Taschen in 1967 for
This months interesting links
| December 2021