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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.

Wednesday, May 14, 2025

Koffie?

In the evening, I went to see the exhibition Koffie? at B93 with works by second year students from the AKI. I found the following works noteworthy:

Tuesday, May 13, 2025

25 years

Today, it is 25 years ago that the fireworks disaster took place in Enschede. These weeks the drama series De Vuurwerkramp is shown on Dutch TV, which is loosely based on the disaster. Some days ago, I also read a Dutch news article that talks about six people being on the company premises in the hours before the disaster took place and that those people ignited some fireworks. There are some photographs taken shortly before the disaster that show a launch tube for so-called shells in front of one of the work bunkers. (Only people with knowledge of the subject and keys to the storage places could reach these launch tubes.) The article also talks about some business conflict between the owner of the building and previous owner of the fireworks company, who wanted to sell the building to the municipality, and the current owners, who were against it. The suggestion was made that the idea of igniting fireworks could cause the neighbourhood to complain. Many people in the neighbourhood were not aware of the large amounts of fireworks stored at the company or even that there was a company involved with fireworks.

Monday, May 12, 2025

Link

Sunday, May 11, 2025

Link

Saturday, May 10, 2025

Paviljoen #3

I saw the exhibition Paviljoen #3, a joined collaboration of Nikolina Karoulla and Havva Malyalizade, two students from the AKI. I watched a short video of Havva (if I am not mistaken) washing a sheet in a tube outside. Nikolina had made some prints from photographs it looks like on self made paper.

Thursday, May 8, 2025

Links

Wednesday, May 7, 2025

C-compiler: Determining types

I finished the next small step in developing the C-compiler for parsing the Tiny C Compiler, which is determining the type of every expression. I had to make some changes to earlier code I wrote and I also implemented a hack for the one case where an enumeration type is defined inside a structure type. The constants defined with an enumeration type have global scope.

Links

Sunday, May 4, 2025

Exhibitions and maker festival

This afternoon, I first visited the exhibition Kamphuis at Galary Dédé Grützmacher with works by Mimi Kamphuis, Sicco Kamphuis (in cooperation with Sonja Ipek), and Henk Kamphuis. Next, in the same building, I saw the exhibition The Great Unknown at Het Robson - Vierkant with photographs by first year students from AKI Crossmedia Design. I liked the following photographs: On the table in the middle there was a collection of books of which I liked:

From there, I biked to Tetem art space where the Maker Festival Twente was help. I first saw the exhibition CAOS, an interactive glass installation, by Jeanine Verloop. I found it quite interesting. I walked around the Maker Festival, which clearly was targetted at children, At one stand, people were putting together 'energy-pendulum make-it kits'. A lady asked me if I also wanted to make one for free. She said it would only take half an hour to put it together. I accepted her offer and started at 15:38. After I verified that it worked, I took it partly apart such that I could put it in my backpack. I also helped another child to get it working. I failed, but it was due to a missing jumper on the PCB. At 16:14, I continued walking around the festival.

Saturday, May 3, 2025

Small steps

In the past week, I got stuck working on the C compiler I am working on. This morning, I realized that it was because I was taking a much too big step, trying to solve a lot of problems at the same time. I realized that I should take small steps. That is always a good strategy, to break-up a problem into smaller steps. In this particualr case I was trying to solve: With the last point I was also trying to solve the problem that in a simple assignment in C, the left and right hand side look the same, but are interpreted slightly different. The left hand side should return a memory location and the right hand side should express a value. A variable usually represents a memory location (of some defined size) and when it appears in an expression there is an implicit operation to take the value from that memory location. I have not figured out the rules for this implicit operation for more complex expressions involving array operations and members of records, possibly in combination with the address-of (&) operator. Because I know that the code I want to compile has no bugs, I am attempting to implement the type algorithm without any checking for NULL pointers. Maybe add some code to display the tokens that are being parsed when it is needed for debugging.

Magnolia sprout?

Below a picture I took this morning. It shows two sprouts. One of them, the left, could be from the seed from our magnolia that I harvested last year. The other seeds, in the other two pots, have not surfaced yet. The other sprout is from a seed that Conny found between the vegetables we received last week from the farm.

Thursday, May 1, 2025

27.3° Celcius

The temperature at Twenthe Airport has gone up to 27.3° Celsius, which is the same as I mentioned on this date last year. Although it is not a record, it does make it the first summer day (defined as the temperature gets above 25°C). According to the offical records, the record is 27.5°C for last year.

Link

Wednesday, April 30, 2025

Link

Tuesday, April 29, 2025

Exhibition

This morning, I was at the university and I took the opportunity to check if there were any exhibitions at the Vrijhof building. First I saw an exhibition with nature photographs called Nature in Focus with what looked like pictures taken around the campus. Next, in the exhibition space, I saw the exhibition Artifical Intelligence with works by Björn Zielman that are made with the help of AI generators.

Monday, April 28, 2025

Links

C-parser

I have finished (a first version probably of) a C-parser for the Tiny C Compiler (TCC) sources and for the program itself. This builds on the C-preprocessor I finished on April 17. I still had to fix some bugs in the C-preprocessor code. The parser can be found in the commit 93fba047. The parser is implemented as a recursive descent parser with a lookahead of one token (making it a LL(1) parser) that resolves ambiguity using the type of previously declared identifiers. This is a very different approach than the one taken by, for example, IParse, which when parsing a C program with the C grammar (based on the published C grammar) without using the semantical information about previously declared identifiers, has to resort to back-tracking and possibly unlimited look-a-head. I knew that C was originally designed to be parsed in a single pass and was hoping that I could implement a simple recursive descent parser that would work for the target programs that I has in mind. It did work out, but I can think of some fragments, where it might not have worked. I noticed that TCC depends on quite a lot of standard library functions and it looks like it could be less. For example, there are both FILE (like fopen) and file number base functions (like open) used. This means that I will have to implement quite a number of functions for the standard library that is needed. The next step probably is going to determine the type of the nodes of the abstract syntax tree for expression. The program does not yet build any abstract syntax tree for the statements.

Links

Sunday, April 27, 2025

Links

Saturday, April 26, 2025

Last magnolia flower

This morning, I took a picture of the last flower on our magnolia. It is on the highest branch. I usually prune those branches.

Links

Wednesday, April 23, 2025

Book fair Glanerbrug

I went to the book fair in Glanerbrug. There we about thirty people waiting outside when the doors opened at ten. There were not many interesting books in the art section like in previous years. At 12:51, I bought the following books and magazines:

Tuesday, April 22, 2025

Link

Saturday, April 19, 2025

Book

At 12:50, I recieved the book Prospects & Concepts edited by Mirjam Beerman and Stijn Huijts, written in Dutch and published by Mondriaan Fonds in February 2017, which I had bought on Friday, April 18, 2025 at 15:32 from Mayflower for € 6.00.

Thursday, April 17, 2025

C-preprocessor implemented with iterators

In the past half year, I have been working on a C preprocessor for the Tiny C Compiler using iterators. This evening, I pushed the commit 8084af1c, with implements the C preprocessor (it seems). I already created a partial implementation almost two years ago on Tuesday, April 25. In the past week, I finished the macro expanding part including support for '##' and '#' operators.

Tuesday, April 15, 2025

Design Automation & Embedded Systems

Together with a colleague, I visited the Design Automation & Embedded Systems event organized by FHI in 's-Hertogenbosch. I attended a number of presentations and visited the various stands of participating companies. Several talks were about the Cyber Resilience Act that will come into effect next year. At the stand of Dekimo, I was given a resistor decade gadget made from a single PCB.

Book

I recieved the book Prospects & Concepts edited by Noor Mertens, written in Dutch and published by Mondriaan Fonds in February 2016, which I had bought on Thursday, April 10, 2025 at 09:53 from Osdorpse Boekenman for € 6.00.

Link

Saturday, April 12, 2025

Going into the city

I went into the city and at Fotogalerie Objektief, I saw the exhibition Forget Me Not with photographs by Roland Icking. The exhibition had photographs from the following projects: After this, I went to Concordia where I attended the opening of the exhibition AKI Paviljoen #2 with works by Meijke de Jong and Caroline Schot. From Meijke I liked the work Village best and from Caroline the work Antropoceen.

Link

Thursday, April 10, 2025

Seeing & believing

This afternoon, I went to Rijksmuseum Twenthe to see the exhibition with Peter Struycken. I learned a lot about colour usage in medieval paintings. The light in the exhibition was rather yellow, due to which the blue colour appear very dull, not like the original were intended when the paintings were made by day light. We looked at the following painting: And from the teasury rooms: We also walked through the rest of the museum seeing the other exhibitions.

Wednesday, April 9, 2025

Night Shift

In the evening, I visited the exhibition Night Shift: Do dreams affect our reality (Online catalogue) at B93. I found the following works noteworthy:

Friday, April 4, 2025

21.8° Celsius

The temperature at Twenthe Airport has gone up to 21.7° Celsius, which breaks the previous record of 20.9° on this date in 2005.

Democracy is instable

I have long argued that the weakness of democracy is that it that it generally does not take the most intelligent decisions, because you only have to convice the dumbest half of the voters to get your way. This is also true for a representative democracy, where you are often able to select your representatives on being loyal to you. For that reason, representative democracies have an inherent weakness to change into facism and/or another autocrative political system, often through oligarchy or particracy. Today, I realized that it is almost inevitable based on evolutionary principles and that it is just a matter of time for a power to arrive that will be able to pervert democracy. We are clearly seeing happening this in the United States of America, as it has happened in other countries before and is also happening in some countries in the rest of the world at the moment. People are inherently racist and it's pretty easy to fuel and exploit that. Even a strong constitution does not prevent a democracy to disintergrate as we are now seeing in the USA. Once the congress and senate are no longer holding the president accountable and allowing him to act like an autocratic ruler that no longer regards the judicial powers, that president can simply overrule the consitutions without being impeached.

Links

Wednesday, April 2, 2025

AKI Paviljoen #1

I went to see the exhibition Sharing Together, Playing Together at Concordia, which is a collaboration between Chimène Wiersma and Sofie Reijerman, two third year students at the AKI who worked together in this exhibition as the title also expresses. I feel that they did a much better job at this than the two artists of the Doublet #7 exhibition. The exhibition is the first of four that are part of what is called AKI Paviljoen.

Tuesday, April 1, 2025

Driest month

Last month was the driest March on record and it looks like it could stay dry for a long time. See this map with the values per weather station. Around where we live, it was about 3mm, where the average over the years 1991-2020 was around 60mm. It was also a very sunny month. See this map with the number of hours sunshine. Around where we live, it was about 227 hours, where the average over the years 1991-2020 is 135.7 hours. It was also about 3.5°C warmer than compared those years. This is due to a rather persistant high-pressure area, which is also causing exsessive amount of rain in the mediterranean sea area like today on the Greek tourist islands of Mykonos and Paros.

Link

Saturday, March 28, 2025

TkkrLab: Open day

Today is the International Open Hackerspace Day 2025. I went to the open day at TkkrLab. Before any guest arrive, I helped a bit with vacum cleaning the stair. I had brought some puzzles with me and the DVB-T+FM+DAB to show how to track planes with dump1090. Another member of the hackerspace had brought a 3D printed sock nitting machine. Shortly after noon, we went outside and observed the partial solar eclipse using two sheets of paper where one of the sheets had a small hole. I showed some guests around our hackerspace. Others did the same.

Friday, March 28, 2025

Rotterdam Art Week

I went to Rotterdam to attend various activities related to the Rotterdam Art Week. I went there by train.

On Anarchism

In the train, I finished reading the book On Anarchism by Noam Chomsky, which I started reading on December 10, last year, after I bought it on October 22. I did not find the main proposition very realistic especially if you realize how in the past decade people all over the world have been embracing fascism so easily it seems. I found the middle part about Spanish Civil War, the most interesting.

Art Rotterdam

I first went to Art Rotterdam. There I also saw the Propects exhibition. At Art Rotterdam, I found the followings works (presented at various galleries) noteworthy:

Prospects

From the Prospects exhibition, I found the presentation of the following artsts noteworthy: Janne Schimmel, Jesse Fischer, Francisco Baquerizo Racines, Gizem Üstüner, Marloes Roeper, Livia Ribichini, Michelle Piergoelem, Lou-Lou van Staaveren, Rosa Ronsdorf, Nolwenn Vuillier, Lilli Weinstein, Adam Centko, Biba Cole, Ugo Petronin, Luke McCowan with Pier at Scheveningen, Meerkoet in the Haangsebos, and Pier at Scheveningen, 2023, Shreya de Souza, Bianca Carague, Alexander Jermilov with Histories computer simulation, 2024, Antrianna Moutoula (with a performance), Annabel van Royen, Ivna Esajas with trying to keep it together, 2, 2024, Oxiea Villamonte with Next of Kin, Mother and daughter, 2025, Mayis Rukel with Movement Song, 2025, Sabine Rovers with We've Always Been Here for You - The Magical Power of Forgotten Plants were you could take one of the cards of the exhibition (I took the a card about the magnolia), Tianyl Zheng, Meike Legêne with De vrouw en de Wolf (photographs and book), 2024, Emilia Martin, Maria Paris Borda with Composición de Luga, 2025, Amrith de Zoete with Merrily II, 2025, Marcos Kueh with KENYALANG CIRCUS: Reconcilliation, 2024, Layla May Arthur, Mari Kolcheva with Language is the Only Homeland, 2023-ongoing, Liza Hoube, Bebe Blanco Agterberg with De nieuwe waterwerken - Tableau I-V, 2025 Rick can der Klooster, Dimitri van den Wittenboer with Home, 2025, Hedwich Rooks with PetrifiCāre, 2025, Christos Mavrodis with In an Endless Reflection, 2024, Hannah Meijer with Markings #1-3 and Symbols #1-6, 2024, Urša Prek with Glory Days, 2025, Dario di Paolantonia with One minute of Distraction, 2025, Lu Lin with Out of Blue Dinner, 2024, Nael Quraishi with An Attempt at Exhausting Several Benches in Karachi, 2025, Jesus Canuto Iglesias with The Sensor, Censers, and the Holy Sensers, 2025, Alexandra Subota with Pink Paradise Punch 2025, and Manju Sherma with Change X, 2024. I got a copy of the catalogue Prospects 2025, edited by Milo Vermeire, written in Dutch, and published by Het Mondriaan Fonds in March 2025, for free.

Buy or Burn: Relics of the Future

At BRUTUS, I saw the exhibition BUY OR BURN: Relics of the Future. I found the following works noteworthy:

TEC ART

At TEC ART, I went to see the exhibition The Brght Side of Dystopia. I found the following installations noteworthy:

Piet Zwart Institute

At the Piet Zwart Institute, I saw the Appreciation exhibition (which include some studios). I like the following works and studios (if I have correctly mapped numbers on the floorplan with the works on display):

The rest

Next, I went to the Pen Plotter Party organized by WORM at the UBIK theater. At this Pen Plotter Party you could order an icecream plotted on three HP 7475A pen plotters (if I am not mistaken) where you could select a coloured sheet, the cone, the icecream, and the topping, all in the colour of your selection. After this, I got a chicken doner kebab at Shoarma De Cocosnoot. I had planned to visit MaMA next, but from the outside it did not look worth paying € 2.00 to go inside. I looked around a bit a bookshop Donner and then decided to take the metro to Wilhelminaplein and from there I walked to pop-up gallary of debsaysyes. They were at the point of closing but allowed me to have a look first. I noted a work by the German artist Franz Licht. I realized, I only saw a small part of the Rotterdam Art Week. Maybe next year, I should stay in a hotel for some days.

Wednesday, March 26, 2025

Installing dump1090

I spend some time installing dump1090 (again). The following commands can be used to build the required software: the following command: 
git clone https://github.com/librtlsdr/librtlsdr.git
cd librtlsdr
mkdir build
cd build
cmake ../ -DINSTALL_UDEV_RULES=ON
make
sudo make install
sudo ldconfig
cd ../..
git clone https://github.com/antirez/dump1090.git
cd dump1090/
make
To make it work with a DVB-T+FM+DAB dongle, you might have to add the file /etc/udev/rules.d/10-rtl-sdr.rules with the lines: 
# original RTL2832U vid/pid (hama nano, for example)
SUBSYSTEMS=="usb", ATTRS{idVendor}=="0bda", ATTRS{idProduct}=="2832", MODE:="0666"
And if your version of Linux loads a kernel module that connects to the dongle, you might have to add the file /etc/modprobe.d/no-rtil.conf with the lines: 
blacklist dvb_usb_rtl28xxu
blacklist rtl2832
blacklist rtl2830

Tuesday, March 25, 2025

Book

At 14:34, I received the book Emigre Fonts: Type Specimens 1986-2016, edited by Rudy VanderLans, written in English, and published by Gingko Press in 2016, ISBN:9781584236207, which I had bought last Saturdayat 18:53 from Mayflower in Leiden for € 39.99. Although, I ordered it through a website for secondhand books, it was shrink wrapped. The primary reason to buy this book is because I saw it in the collection of the Stedelijk Museum on Saturday, March 15.

Monday, March 24, 2025

Flowers on magnolia

Today, more flowers opened on our magnolia. Below a picture of one flower with in the background many that have not opened yet.

Link

Sunday, March 23, 2025

Some flowers opened

Yesterday at the end of the afternoon, I saw that some flowers on our magnolia had opened. I counted six that looked like they had at least opened a bit. Today, I did not get as warm as yesterday, but it is still got rather warm, 18.1°C at Twenthe Airport. We have seen a lot of clear blue skies in the past weeks and probably got twice as much sunshine as usual. But that seems to be changing for the coming week. Last night, I looked at the three pots with seeds in our shed, which I put there in October. Today, I brought them in and Conny gave them some water.

Link

Saturday, March 22, 2025

Links

Friday, March 21, 2025

21.7° Celsius

The temperature at Twenthe Airport has gone up to 21.7° Celsius, which breaks the previous record of 17.5° on this date in 1956 by 4.2°. This is the third weather record of 2025, if I am not mistaken. On the news they were talking about the fourth national weather record this month.

Links

Tuesday, March 18, 2025

Introduction

Diaries
May 2025
April 2025
March 2025
February 2025
January 2025
December 2024
2025
2024
2023
-- contact --

Family

Frans
Conny
Annabel
Andy
Li-Xia†
Others
Pictures

Collecting

Books
Maps
Bookshelves
Art works
Computers
Cameras
Trips
Flights
Weddings
Funerals
Reading
Movies
Useless lists

Hacking

My life as a hacker
Signature programs
Software enginering
The Art of Programming
HTML to LaTeX
JavaScript
eXtreme Programming
Programs

Puzzles

Hamilton cycles
cutting sticks
Califlower fractal
more...

SARS-CoV-2

Tracking
Trends
Prediction
nextstrain.org/ncov


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