Georg's Blog

Why is it so hard to cancel a service?

2008-05-27T10:23:00.006+02:00

I sent a Dutch insurance company, Zilveren Kruis Achmea, a note that I would like to cancel my ongoing travel insurance. Here is their response:

Graag ontvang ik van u bericht of u nog ingeschreven staat in een Nederlandse gemeente.

U kunt namelijk de reisverzekering niet behouden wanneer u in het buitenland woont. Volgens onze voorwaarden kunt u deze verzekering alleen afsluiten en behouden als u in Nederland woont.

(Translation: Please reply to tell us whether you are still living in The Netherlands. That's the only way you can keep your travel insurance, you see.) What part about cancelling my travel insurance do they not understand?

As a PhD-student here remarked, it is a little bit like that old joke:
Me: I would like to have a coffee without milk.
Zilveren Kruis Achmea: But we don't have milk...
Me: A coffee without cream then!

Remaking Old Games

2008-03-29T17:19:00.009+01:00

The past couple of months I have been working on a secret project. I don't want to say much yet, but what I can say is that it is a remake of my favorite computer game ever.

Why Remakes?

Working on this project made me think about the process of remaking an old computer game. To remake an old game is a relatively easy way to make a fun game, because you only have to solve what I'd like to call "local problems". With a local problem I mean a problem whose solution does not affect any other problem. That is, local problems can be solved one by one without worrying about the big picture. Designing a whole new game on the other hand, is a global problem, since many decisions you make in the beginning will have a huge influence on what your game will look like in the end. I think a large project has a much bigger chance of completion when it is clear at all times what needs to be done next, especially when working with a team.

Besides this, most of the technical restrictions the original developers struggled with are gone, allowing for easy improvements in many different areas. For example, back in the early eighties developers were very limited as to what kind of music could be played from a home computer, not in the least because of memory restrictions. Yet by restricting to the essence of the songs the composers had in mind, they still managed to create very catchy game music. And this music is just screaming to be accompanied by that deep base line that would never have been heard through those PC-speakers, a call for creativity through restriction. This is similar for graphics and sound effects.

A third great thing about remaking an old game is that your game automatically has an audience. Many people will like to play the game for reasons of nostalgia. And this is what makes it a lot of fun to remake it as well!

In short, it is relatively easy to complete a remake and many people will be interested in playing it.

Recreating Tile Maps

When I was working on my project there was one area in particular that consumed a lot of time: assembling building pieces (tiles) into tile maps. It is not that I really mind doing it, normally I would be laying a large puzzle in the Christmas holiday, and this year I decided that I would instead reassemble forty tile maps. However, when I had completed about two thirds, I discovered losslessly compressed images of these tile maps that were created directly from the game (as it turns out, for most old computer games such map images are floating around on the internet, often created from screen shots by obsessed gamers ;) ). Only then I decided that I would write a tool that would automatically assemble the pieces into a tile map file.

An example of a losslessly compressed tile map image.

I had chosen to make my maps in the Tile Map XML-format, a format that is used in Tiled, a tile editor written by my friend Bjørn Lindeijer and Adam Turk. From this open format, it should be easy to export it to any other tile map file. However, the hardest part would not be to assemble the tiles in a Tile Map XML-file, but to find a way to arrange the unique tiles in a way that a human could work with it. After all, at some point these tiles will need to be redrawn, and then it would be convenient if they are arranged in a coherent way. Together with Bjørn, I created a heuristic that uses how often tiles are found to be adjacent in the image of the tile map.

An example of a unique tile image.

The Python program Image2Map.py uses this heuristic to create an image of the unique tiles. There is a separate program MapWriter.py that uses this image and the original tile map image to create a Tile Map XML-file. The heuristic does a quite decent job for the information that can be extracted from a tile map image. We realized that it would be impossible to come up with an algorithm that would create a unique tile image just like a human does, because we humans recognize the objects in the tile map image, while the computer only recognizes the relationship between the tiles. We therefore split the functionality up into these two command line programs to give the user the opportunity to adjust the unique tile image before creating a Tile Map XML-file.

Example Usage

The above picture was created from the tile map image JansHouse.png by typing python Image2Map 8 8 JansHouse.png. Here the argument 8 8 corresponds to the 8 x 8-tile size. After this, a Tile Map XML-file can be created by typing python MapWriter.py 8 8 JansHouse.png JansHouse-Tileset.png. Of course, you need to have Python installed for this to work at all, and you additionally need the python-networkx package (in Ubuntu/Debian, type sudo apt-get install python-networkx).

If you have Sun Java Webstart installed, the resulting file JansHouse.tmx can then be opened by going to Tiled's Website and clicking on "Start Now!". Alternatively, if you have a Java Virtual Machine installed, downloading Tiled 0.6.1 and running it with java -jar tiled.jar should do the job.

Parking Space

2007-12-20T19:48:00.000+01:00

Some months ago Annett's parents gave us their old car. We don't use it so often, because inside Oslo it is much easier to travel by bike and subway. However, whenever we visit her parents, it saves us over hundred euro in expensive train tickets. Since a couple of weeks we are therefore renting a parking space next to our apartment.

There is a problem that the parking place still lacks a sign that it is ours, and so when we came home tonight from shopping for a Christmas dinner, we found our space blocked by a big car. Not only had this person parked at a place where it was not allowed, she had also managed to cover the two remaining spaces with her bad parking skills. Luckily we have a very small car and we were able to squeeze it between her car and the bushes.

When I went down five minutes later to shop for groceries, a woman was just about to drive away. Now I was annoyed, and could probably have said it much more polite than I did, but I asked her if she was paying for that place, because we were. She answered with "unnskyld?" (I'm sorry?) and I switched to Norwegian.

It was an unbalanced discussion. Not because I wasn't speaking in my native language, but because of the facts we presented to each other:

WOMAN: I heard two years ago from my daughter that these parking places are for guest parking.
ME: We called a couple of days earlier with the responsible organisation and got assigned this parking place. Also there is a sign that says "no parking" at the end of the street.

As you can see she was in dire need to strengthen her argument, and so she did. Repeatedly she pointed out her authority in this matter, explaining that "this is how we do it in Norway." The message was clear, she was not going to let a foreigner tell her what she shouldn't do.

I was shocked. Should I've explained to her that she should feel privileged to have me here? Someone with an education Norway never had to pay for? Of course not. There is no arguing with people like this. Instead I chopped it off by saying that I didn't think we were going to agree. We should buy one of those wheel clamps, although that won't give us our parking space back...

When Solomon said there was a time and a place for everything, he had not encountered the problem of parking his automobile -- Bob Edwards

Antibiotics, Visitors in Oslo, Presenting SAGE, and the Poincaré Problem

2007-10-27T13:07:00.000+02:00

Following a recurring theme on this blog, I would like to start with an excuse for not writing for so long. It has a been a busy time, and a lot of things have happened.

Annett has been ill for the past four, five weeks. She has been bedridden with a sinus infection, that just didn't go away. After her third antibiotics she visited a specialist (Dutch: KNO-arts) who examined her thoroughly for an hour. The result: there was no sinus infection anymore, and he couldn't pin point the reason for the remaining pressure on her head and the headaches. Among the possible causes, he suggested the strong antibiotics itself and the use of pain killers, generating a vicious circle. Next week she will visit a neurologist.

Luckily there were times where she felt a bit better. Joost and Annieka payed us a six-day-visit ending Tuesday last week. They brought some delicious stroopwafels, taai taai and pepernoten. We rented for a long weekend a cabin in Eidfjord, a city on the west coast a five-hour-drive from Olso. The cabin was connected to the sea with a beautiful view out over the fjord ("een doodeenvoudige zeeinham"). From there we planned to take day trips into the mountains. Unfortunately Annett didn't come along for obvious reasons, and I only participated the first day because I fell ill. Nevertheless we had a cozy time. Oude jongens krentenbrood, as we say in Dutch.

Some weeks ago I gave a talk (HTML, PDF, ODP) about SAGE for my algebra group in Oslo, mathematics software that I wrote about earlier on this blog. It is the first presentation that I give in a new style, free from data bloated slides and dull bullet points. Instead, the slides aim to capture the essence of what I talk about, and support me in making an emotional connection with the audience. My journey for improving my presentation style started with the discovery of Garr Reynolds' blog Presentation Zen, which aims to reform the way Power Point presentations are traditionally being given (I'm looking forward to the book!). There I read about the book Beyond Bullet Points by Cliff Atkinson, which helped me to pour my presentation in the form of a traditional story structure.

Other good news is that my PhD research is gaining some momentum. After the holiday my supervisor and I decided to put what we had been doing so far on hold, because I felt stuck. We switched our attention to another related topic that we had been looking at in the beginning of my PhD thesis, called the Poincaré problem. The past few weeks I've been reading recent literature on this topic, and right now I'm reading in detail some articles where there seems to be room for improvement.

The upcoming week is going to be busy. Thursday and Friday there is a national algebra conference organized in Oslo, directly followed by KoMIN, a conference for Norwegian graduate and undergraduate students. There I'll probably give a short presentation on my PhD research.

But I'm looking even more forward to the weekend after that. Annett and I will be in the Netherlands from the 9th until the 14th of November, so that we can be at my father's birthday. Besides looking forward to see my family and friends again, I'm looking forward to eat typically Dutch Chinese food, which is very different from the Chinese food you get in other countries. I haven't eaten this in almost two years. Yum!

Wikizine

2007-08-24T18:15:00.000+02:00

Wikipedia is one of my long term interests. In January 2002 my brother introduced me to Wikipedia, and I started editing and creating some articles. Back then there were only 20,000 articles in the English version! Later I translated some articles between the Dutch, English and Norwegian Wikipedia's.

Although I have never been a major contributor, I did spend some time following its progress. Especially the first couple of years it was very exciting to follow the explosive growth of Wikipedia. I remember one summer holiday week doing nothing else but reading on Meta-Wiki on ideas that were being realized on each of the Wikimedia chapters. In 2005 I even visited the first Wikimania in Frankfurt together with three fellow enthusiasts. We wrote articles about wiki's, Wikipedia and an interview with co-founder Jimmy Wales later that summer in the Periodiek, the glossy magazine of our student association (I mention this because I'm still very proud of our little magazine).

However, after this my interests shifted to other things. Wikipedia had become so popular that it was just too hard to keep up with all the developments, and after three years I also wasn't all that enthusiastic about the milestones anymore. Nowadays Wikipedia remains a minor interest to me, and I always enjoy it when a Wikipedia related article pops up in my RSS reader. My favorite source for this is Wikizine, an independent newsletter on what is happening at the Wikimedia projects. Since I just can't understand why there are only about 700 readers subscribed, I decided to do some advertising for them. If you're interested in Wikipedia, this is a valuable source to keep you informed.

Trip to Ålesund

2007-08-04T18:55:00.000+02:00

At ten in the morning we were on our way to Ålesund, a seasided village of which the largest part lies on an island. Being known for the Jugendstil, Ålesunds city image is largely dominated by stone houses built in this style.

When In 1904 a fire burned down large parts of the city, Kaiser Wilhelm II, who had been a frequent visitor to the area, had genereously sent several ships with resources for rebuilding the city. This time, though, the houses were to be build out of stone instead of wood and in the contemporary Jugenstil.

(image by Michael Krautwasser available under the GFDL 1.2)

The girls and me discovered that from the top of the local hill Aksla you can get a great view over the city. You can see this for yourself on the pictures above. Although we only spend three hours in Ålesund, this was enough to visit the Jugendstil museum and get a general feel of the atmosphere.

My parents on holiday in Norway

2007-08-04T17:28:00.000+02:00

This year my parents did something they haven't done in thirty years: they spent their summer holiday driving through Norway. And so did we. To check where they were going, we decided to meet up with them at the cabin of Annett's parents. Don't get me wrong, it was the only way we could avoid running in to them on our own holiday.

At the cabin Gaute introduced us to his new girlfriend Runi, and we went fishing with the eight of us. We caught a lot of fish, although my mother caught mostly water plants, trees and other leashes.

There is a Norwegian proverb stating that there is no such thing as bad weather, just bad clothes. In the pouring rain, Annett's mother, my father and me the next morning took the boat to fetch a net. Because I borrowed effective rain gear, the rain wasn't bothering me at all. Instead it made the fishing experience somehow more real. The sky and the water both had the same gray color, and the only color was coming from the forest: several shades of green, fading to gray with distance. Pretty, in a mystical sort of way.

Afterwards we prepared the fish outside in the rain. Outside, to keep it clean inside. This time Bastian had to share the fish heads with Inu, but he didn't seem to mind. I guess more than forty fish heads is a lot, even for an everhungry Labrador.

Inu had the time of her life. She was constantly exploring the area around the cabin. We didn't bother anymore to keep an eye on her all the time. She managed to fall into the water, and so she swum for the first time. And she lost her first milk teeth. A couple of times we had to put her in the room, because she wanted to play with Bastian all the time. We think of her as the annoying side kick of Bastian. This is too much for Bastian, with his hundred dog-years he just doesn't manage to play so much anymore.

It means a lot to me that my parents know what my life here is like. By the time I post this on my blog, Maarten and Marian have payed us a visit. In the autumn we plan to go camping in the mountains together with Joost and Annieka. Bjørn will probably start working for Trolltech in Berlin, and might go to its main office in Oslo now and then. I'm glad that our advertising of our sleeping couch is paying off.

VR Panoramas and Google Earth

2007-07-08T12:29:00.000+02:00

When I was enjoying a stunning view from a mountain in Nordfjordeid, I was discussing with Pål how great it would be to embed a layer of Quicktime VR Panoramas in Google Earth (here are some examples of small VR Panoramas). The ability to embed URLs in the panoramas would then make it possible to jump location by clicking inside your panorama, hopping for instance from mountain top to mountain top!

I've been fascinated by these panoramas for some time now, and wrote about them long ago in connection to generalizing point-and-click adventure games. As for now, I don't think there exists an open alternative to these, and I don't think it is possible to create them in GNU/Linux. Hopefully somebody steps up.

Know thy audience

2007-07-04T15:13:00.000+02:00

About a month ago I went to a talk by a famous Russian professor, who came to talk about something very important he had contributed to mathematical physics thirty years ago. Now the room was filled with mathematicians, and there was also a handful of people from physics. If I remember correctly, the topic had its roots in Quantum Field Theory, a theory that I briefly touched upon when I still studied physics. Nevertheless I didn't understand at all what he was talking about, and looking around I estimated that at most ten percent of the audience might have a clue what he was talking about.

Ten percent!

At most five of the fifty people were not completely wasting their time. No matter how ridiculous this may sound to an outsider, this is not at all uncommon for academic talks. So what was the rest of the audience doing there? Most probably thinking about their own research. Maybe many of them were actually thinking that the majority of the audience had no problems keeping up with the speaker. What I'm sure of is that after a countless number of incomprehensible talks, most of the idling ninety five percent had accepted this situation and learned how to cope with it.

Now before anybody rightfully accuses me of a holier-than-thou attitude, I have to admit that I was guilty of this as recently as three weeks ago. While my audience consisted of just three people, I think large parts of my talk might not have been understood because I assumed a wrong background. Talking for just a couple of minutes about their background could have prevented this. The solution is obvious: let there be no misunderstanding about the (target) audience from either side. Below I worked this out in a little more detail from the point of view of the audience, the speaker and the organizers.

What can the audience do? When you plan to go to a talk you should always try to find out what the level of the talk is going to be. Either contact the organizers (who often don't know this) or directly contact the speaker. If the talk is in the same building, don't shy away from going there and asking the speaker directly. This is just as beneficial for the speaker as for you: it allows him to become familiar with the audience and thus make a better connection. Once you feel that this talk is aimed at you, you no longer feel that if you don't understand the talk, then that is because you don't belong in this room. I often find it much easier to ask questions when I am sitting in the front, because you directly face the speaker and don't have to get past the audience first. Remember, asking questions also helps the speaker to make a connection with the audience.

What can the speaker do? Always discuss with the organizers what kind of audience you can expect. When you are able to send out an abstract, add a paragraph discussing the background that you assume your audience to have. Let there be no misunderstanding about the target audience. Just before the talk go around the audience, start establishing a connection, and find out what kind of people have come to the talk. For me this has as a side advantage that I tend to be a little less nervous whenever I see familiar faces in the audience. If done properly you will manage to give an understandable talk without boring people to death.

What can the organizers do? Discuss with the speaker what the target audience will be, and communicate this to the audience in the promotion of the event. Make sure there is an abstract of the talk containing a paragraph about the target audience. Ask the speaker to give more details about what he will talk about, and use this to reconsider the target audience. In short: be more than a medium, don't leave the communication up to the audience and the speaker.

Coding Theory Conference in Nordfjordeid

2007-07-02T23:47:00.000+02:00

After my exams in Statistical Methods and Spline Methods and a presentation, I found myself half asleep in the nightbus bound for a conference in Nordfjordeid, a small city at the west coast at equal distance from Oslo and Trondheim. The nine-hour trip made me realize again how big Norway actually is. The length of Norway is comparable to the distance from the top of Denmark to the South-West of Portugal. And on this scale, my trip would only bring me to the German border.

The topic of the conference was Coding Theory, the mathematical theory for encoding information in such a way that you can correct several errors that occur from transferring the information without using too much additional bandwidth. The three lecture series were all quite good, and so were the practice sessions. The conference reassured me just how important it is to have practice sessions, and not only passive lecture sessions. Most of the lectures were understandable, but I only managed to get a grip on them after doing the practice sessions. Furthermore it was a lot of fun: we had a small active group of nine people from nine different countries, and it was fun to figure the answers out together.

We had some spare time during the week, which we spend going up the mountain, playing football, swimming and visiting the largest glacier in Norway. It now seems that I overdid this all a bit, as the next ten days I wasn't able to walk on my left foot anymore. Friday I went to the doctor, but nothing could be seen on the x-rays, so it is probably not as serious as it feels. Fortunately I sensed a small improvement yesterday and today. Hopefully my foot will be mostly healed when we go on a car holiday through Norway in two weeks...

Video presentations on Zentation.com

2007-07-01T14:10:00.000+02:00

For most presentations that I have attended, the accompanying visuals are what Garr Reynolds from Presentation Zen refers to as a slideument, an unfortunate compromise between slides and a document. On the one hand, these slideuments are used as suboptimal hand-outs that are distributed after the talk or can be found in the conference proceedings. More importantly, however, these are bad because research has shown that it is more difficult to process information if it is coming at you in the written and spoken form at the same time. So although such slideuments are aimed to enhance the message, they obfuscate it instead. Try it yourself. Next time somebody presents to you a slideument, listen only to the speaker and ignore the slides. Can you focus better on his message?

In all honesty I have to admit here that all my own previous presentations were built around such slides, because this is how you're supposed to do it, right? Everybody does it like that! Note that I write "built around", and this brings me to a second nasty side effect of slideuments: They draw attention away from the speaker. This is probably an important reason for them to be so popular: It makes it easy for people to hide behind their slides. (see Garr Reynolds' eye-opening post about "naked presentations"). But your audience doesn't come to see your slides, then they might as well have read your article or whatever. They come to see you, and make a connection with you.

What I'm trying to say is that slides alone are not enough to transfer your message. You can either read an article, which mostly lacks the (emotional) connection with the writer, or you can view a video of a presentation. However, from most video presentations that you can find on for instance Google Video it is impossible to read the slides, so you're missing out on a large part of the talk. The obvious solution would be to somehow be able to see the slides and the video at the same time. This is exactly what Zentation.com does. Moreover, you can embed such presentations into your blog or website. As a test I include below a talk by Guy Kawasaki on the Art of Innovation.

Got interested? Check out the excellent review by Robin Good.

Update/Warning: It seems the application can only work with Powerpoint slides as for now.

Our little monster is growing up

2007-06-30T15:02:00.000+02:00

Inu has been growing up at a rapid pace. Unfortunately she is not potty trained yet, and she has been peeing and pooing inside at every little corner of our house, although she has a couple of favorite places. Because her teeth are growing they are itching a lot and she needs to chew on everything. Although we cleverly bought her all kinds of chewing toys for this, she seems to prefer the wall, our home trainer, my legs and Annetts purse, shoes and nose. I'm sure we will be able to laugh about this somewhere in the not-so-near future.

We have done a one-month speed course at the Norsk Hundeskole. Here Inu learned more or less how to focus on us, walk nicely in the leash, come to us, sit/lie down and stay down. Furthermore, she is now able to be more or less at ease in her cage and can stay home alone for a whole working day. More importantly, however, we learned how to communicate with Inu, understand her better and show her who is the boss (and who is the dog :) ) and how to reward and correct here. At the last lesson Inu went to the busiest pedestrian street in Oslo and had to lie and stay down while people were passing all around her. Of course she did great!

Annett and I had a lot of fun with learning her how to walk nicely in the leash. To show the dog that it is you who decides where we are going, you have to turn around every time she pulls the leash and go in the opposite direction. Inu just didn't get it, and we laughed our heads of. As you can see on some of the pictures we also had a great time showering her, something I'm sure Inu won't agree on. Oh yes, we took a dog for all the wrong reasons. ;)

Update!

2007-05-04T11:30:00.000+02:00

No excuses this time, just some plain notifications. Annett has updated her blog with a summary of the past two months, and a rant on Chess and our mail company.

We, well actually Annett, also put out a lot of pictures:

Our trip to Barcelona

Easter at Annett's parents, and Inu

My parents in Norway, and Inu.

That, and you can now subscribe to my shared items in Google reader, that is, things that I read that other people might also be interested in. Check it out!

About making onigiri, sushi and dumplings, and our puppy

2007-03-21T10:05:00.000+01:00

Annett has written a couple of posts about us making onigiri (the pictures), making sushi and dumplings with my friends from the CMA (the pictures), and the birth of our puppy! In two weeks we can go and look at her, and six weeks later we can go get her!

The SAGE Computer Algebra System

2007-03-14T12:52:00.000+01:00

For a long time I've been struggling with the following problem. When you start working with a certain Computer Algebra System (CAS), you spend a lot of time becoming familiar with it, adjusting it to your preferences, writing your own functions etc. Because of this, you automatically trap yourself into using one and only one CAS for most purposes, and with time it becomes increasingly difficult to switch to any other CAS. Therefore this choice, this decision about which CAS I would "go for", became a very important one for me.

Unfortunately it is not only very important, but also very difficult. There are many CAS out there, each of them with their own particularly attractive features. Mathematica and Maple, for instance, have a huge user base, and Axiom works with structures that are very closely related to mathematical structures (e.g. categories). In order to make the right choice, an obvious strategy is to make a list of features that can not be compromised on. Of course this is very difficult because typically you only discover what is essential when you find yourself in the position of lacking it. A rather hopeless situation if you, like me, have a relatively limited experience with CAS.

About half a year ago I became acquainted with a CAS that tries to be something distinctively different from the rest, and it is called SAGE. For short, it is a free multi-purpose CAS with a strong interaction with other existing CAS. It is mostly this "strong interaction" that solves my problem, and in my opinion it is a revolutionary piece of software that deserves to be better known. Therefore I will try to give an overview of the features and design decisions of SAGE that make it the best option that I can use and contribute to. Before this large post scares you away, let me remark that you can try SAGE in your browser (at least in Firefox, Safari and Opera).

So what is SAGE?

SAGE aims to be the following:

A complete self contained distribution of free open source mathematics and other special-purpose software for Linux, OS X, Microsoft Windows, and Solaris.

A new library of functionality to fill in the many gaps in functionality in existing CAS. That is, new implementations of algorithms that are generally missing in other CAS.

A collection of interfaces to most other mathematical software systems (both free and commercial), bringing all these CAS under the same roof.

For a CAS whose development started in early 2005, the results are amazing. This is a direct consequence of this third point, of the idea to let SAGE borrow functionality from other existing CAS. Therefore SAGE developers like to say that they don't reinvent the wheel, but build the car.

Figure 1: Don't reinvent the wheel. (Image created by Martin Albrecht.)

Free software and mathematics

Long term followers of this blog know that I am generally a proponent of free software and open source. As I mentioned for instance in my post on Granule, I strongly prefer working with free software when there is the chance to contribute something back to the project, which is almost always the case.

Furthermore I believe that free software projects have the most potential in the long term. Linus Torvalds, initiator of the Linux kernel, said something sensible about this:

I think, fundamentally, open source does tend to be more stable software. It's the right way to do things. I compare it to science vs. witchcraft. In science, the whole system builds on people looking at other people's results and building on top of them. In witchcraft, somebody had a small secret and guarded it -- but never allowed others to really understand it and build on it.

Traditional software is like witchcraft. In history, witchcraft just died out. The same will happen in software. When problems get serious enough, you can't have one person or one company guarding their secrets. You have to have everybody share in knowledge.

Apart from these general reasons to work with free software, there are some special reasons in the case of mathematical software. In particular, some people think that a mathematical result obtained from a CAS can only be accepted if it comes from an open source program. Already in 1993, Joachim Neubüser, who initiated the free software CAS GAP in 1986, made the following interesting remark:

You can read Sylow's Theorem and its proof in Huppert's book in the library [...] then you can use Sylow's Theorem for the rest of your life free of charge, but for many computer algebra systems license fees have to be paid regularly [...]. You press buttons and you get answers in the same way as you get the bright pictures from your television set but you cannot control how they were made in either case.

With this situation two of the most basic rules of conduct in mathematics are violated: In mathematics information is passed on free of charge and everything is laid open for checking. Not applying these rules to computer algebra systems that are made for mathematical research [...] means moving in a most undesirable direction. Most important: Can we expect somebody to believe a result of a program that he is not allowed to see?

David Joyner, professor at the United States Naval Academy and long term contributor to SAGE, formulated this second point as follows:

A result computed by a computer algebra system, whose source code is not "open source", can not be accepted as part of a mathematical proof. Within the general mathematical community, it seems fair to say that a mathematical truth is not a theorem unless its proof is written down for public scrutiny (i.e., "open source") and generally accepted as correct. Just as to verify the correctness of a theorem you can go through the proofs of all the results your theorem depends on, one should be able to verify the correctness of an algorithm by reading the programming code of all the algorithms your algorithm depends on.

Moreover, a typical feature of the mathematical community that uses a CAS, is that a very large part of it is a potential contributor. Such a contribution could be reporting a bug and making a patch, requesting a feature, improving an algorithm or its implementation, or improving the documentation. The possibility to contribute back, to be more than just a user, is an attractive feature for a CAS.

To fully benefit from such an eager audience, one should make it easy for them to contribute. That is, one should give them direct access to the source code. In SAGE this is achieved by just typing the command followed by two question marks, for example plot??, and this results immediately in a box with the source code of the function (though at the moment this only works for native SAGE functions, and it doesn't give you the source code of a function that can be reached through an interface to, say, GAP). Because of these reasons, I find the CAS being free software not something that can be compromised on.

Interpreter versus compiler

William Stein, founder and leader of the SAGE project, explains his choice for using Python and Pyrex in the SAGE Programming Guide better than I can:

Every serious computer algebra system, e.g., MAGMA, PARI, Mathematica, Maple, GAP, Singular, etc., is implemented as a combination of compiled and interpreted code. For Mathematica, Singular, MAGMA, and PARI, most of the implementation is in compiled C (or C++) code; some of these systems tend to be very optimized (subject to the constraints of the algorithms they implement). In contrast, Maple and GAP have a relatively small compiled "kernel" that defines the underlying programming language; most of the system is then implemented in this language. If you do benchmarks you'll discover that Mathematica is much faster than Maple at some basic operations. Likewise, benchmarks reveal that MAGMA is often faster than GAP.

This fusion of interpreted and compiled code is extremely natural for mathematics software; some algorithms are much better implemented in an interpreter because all time-critical steps involve low level arithmetic -- other algorithms, e.g., matrix multiplication, must be implemented in a compiled language in order to perform optimally. Also, existing compiled libraries are sometimes of very high quality, and a compiled language is needed to create the best possible interface to such libraries. It's crucial that both approaches to programming be fully supported. When deciding how to implement SAGE, I searched for months for an environment that could support both approaches. Python and Pyrex provide exactly this in a way that I believe is much easier conceptually than the implementation models of any of the other systems mentioned above.

Personally I love Python, and I couldn't think of any better choice for a scripting language. At the moment I am programming in R for a course in applied statistics that I'm taking. Although it is a wonderful and amazingly complete free statistics environment, its scripting language cannot compare to Python, and I find myself longing for the transparent syntax and list comprehensions in Python. It is only a matter of time before there is also an interface between R and SAGE, combining the functionality of R with the power of Python.

A smart interface

The ordinary SAGE interface is built around IPython. This is a Python interpreter with a pleasant command line that features for example command line completion, which is very convenient for saving time on typing and remembering long function names. Strictly speaking, instead of function, the term method would be more accurate, because the command line completion yields only the methods within the class you are looking. Typing for instance set.[tab], yields all the methods for the object set, like intersection and union.

This naturally leads to an obvious advantage of using an object oriented language like Python: it prevents the global name space from becoming polluted with thousands of very specific functions, making it almost impossible to find the function you're looking for and making it easy to confuse the context in which a certain function operates. Instead, each method is associated to the type of object on which it acts. For example, set.union acts on sets. That being said, some functions can still be called from the global name space, allowing one for instance to write sqrt(a) instead of the rather awkward a.sqrt().

Now most modern CAS have, besides the command line, some kind of a graphical user interface. This makes it easier for users to get started, enables users to work more conveniently with graphical objects and multi line input, and displays formulae in a more readable form. For a CAS, the usual form of such a GUI is a notebook, which is basically a graphical representation of text cells, input cells, output cells and a menu system. An amazing feature of SAGE is that its notebook is not a stand-alone application that runs directly on your system. Instead, it is a web application that runs in your browser and uses AJAX technology to feel like a stand-alone application. This way anyone with a decent browser and an internet connection can try SAGE by surfing to an internet site that runs SAGE. Alternatively, you can run the notebook on your own computer by typing notebook() in your SAGE shell, and surfing to http://localhost:8000 in your web browser. This notebook, I think, is what will attract most users to try out the program in the first place. The fact that it is free software and can be used just by surfing to a website, gives it an accessibility commercial software can never offer.

Moreover, the notebook uses jsmath to display formulae, and if you have installed true type fonts on your computer the result looks as if it were coming from TeX. Calling the function latex to an object, will give you in most cases the code for rendering it in your TeX document.

Figure 2: The SAGE notebook.

Smart documentation

Analogously to the source code, the documentation of a function can be reached by typing a command and one question mark, for example plot?. In a way typical of Python (and e.g. Java), such documentation is automatically generated from the source code. There is a rather specific template this documentation should adhere to, containing a one-line description of the function, the input, the output, examples, notes, references and authors. Apart from providing a very useful tool to keep track of the documentation, the examples can be automatically tested. Because of the nature of SAGE as combining different CAS, each of them complex by themselves, tools for testing for bugs are essential, and this is a rather ingenious way to deal with an ever growing more complex interaction of pieces of code. On the other hand, this ensures that the examples in your documentation are correct.

Apart from this smart way of dealing with reference documentation, SAGE has a convenient way of presenting other documentation. By clicking on the edit-button in the notebook, you can edit the source code of the notebook. The possibility of inserting HTML outside the input cells, gives you a way to present a tutorial, a how-to, or any other type of documentation in an interactive way. A user can then play around with the examples you give in the tutorial, and absorb the information quicker than he would have been able to with a static tutorial. Of course such interactive notebook tutorials are not by any means new, but the fact that you can take them from anywhere with a decent browser and internet connection gives it an accessibility that is unmatched.

A New Apartment

2007-02-28T20:40:00.000+01:00

After living for one and a half month together, though unofficially for me, in a one person student dorm, we finally moved into our new apartment! With only a dining table and accompanying chairs left to come, we are pretty much finished with decorating the apartment. And it's huge with its 53 m² (especially of course when you're coming from a 12 m² student dorm). We were able to print many pictures, mostly from Japan, at Annett's parents' printer at quite a high quality, framed them and attached them to the wall. Although we are not, of course, by any means professional photographers, it most certainly gives the apartment a personal touch.

Saturday evening we held a house warming party and it was very cozy. We managed to narrow our group of selected guests down to a hundred of our closest friends. Just kidding, but in any case we would have had enough tapas for that many people... You know the drill, everybody is afraid that there is not going to be enough food, and you end up with ridiculous amounts of aioli and crackers.

Anyway, by now I have hopefully distracted you enough to shamelessly show of what the apartment features: a very complete kitchen with a dish washer and a small kitchen table with chairs (where we have breakfast every morning), a large storage room downstairs, a huge in-wall closet in the bedroom with a 2m x 1m mirror (to give an impression: all of Annett's clothes fit in there), a nice small desk in the bed room and a new five-person couch that can be turned into a double-bed. Check out the pictures!

Steve Jobs argues for DRM-free music

2007-02-07T09:33:00.000+01:00

Yesterday Steve Jobs, co-founder and CEO of Apple, wrote a post in which he argues for DRM-free music. It is an interesting read, explaining the decision for Apple (and Microsoft and Sony) to "DRM-protect" their music files, the difficulties with having a universal DRM-scheme for all music distributors, and Apple's stand in this matter.

Laurens in 't Gooi

2007-01-08T14:51:00.000+01:00

After a little bit of encouragement from our side, my good friend Laurens started a new blog. This way he's going to keep us informed about all his adventures in "'t Gooi", the snob part of The Netherlands. He himself writes the following:

Basically this blog is for all my adventures in my new town. I'm going to move there in a week and going to start my first real job! I'm moving from "the country" to Snob Land in the Netherlands, also called 't Gooi. Oh boy, I am going to have fun there! So keep in touch and read all about my craaaazy adventures there!

Check it out, and add him to your feed reader!

On Annett's blog and photo pages...

2007-01-02T23:04:00.000+01:00

Annett has written about Christmas at her parents, our last days in Japan, and added some pictures from our last month in Japan, Christmas at her parents and New Year's at my parents and friends. And she also has has a new site.

Check it out! (If you're interested, of course.)

Visiting Hiroshima

2007-01-02T22:07:00.000+01:00

There was one more city we really wanted to visit in Japan: Hiroshima. To avoid some of the planning we participated in an organized though unguided tour, which basically meant that they would book us a room in a hotel, and send us our Shinkansen tickets together with some maps. Amazingly enough, defying some basic laws of economy, it barely cost us more than the price we would have paid for just the Shinkansen...

The day we left Tsukuba I was recovering from a flu that was at that moment starting to get the better of Annett. By sleeping long every night we were able to postpone the worst to the next week (fortunately she didn't miss out on any of here precious microscopy time).

We visited a beautiful, wooden castle, and Milica joined us in our quest to visit the famous Atomic Bomb Dome. Just next to the dome was the Hiroshima Peace Memorial Museum, and both were lying in the Hiroshima Peace Memorial Park, which was built around the hypocenter of the bomb.

In the museum we spent hours reading about the background, and looking at painful pictures, movies and objects, showing us the destructive power of the atomic bomb. One of the horrifying things we saw, was a stone stairs that had turned white everywhere, except an area that clearly must have been occupied by a human. In the museum there was a wall filled with protest letters from the mayor against each nuclear test that has been performed after Hiroshima (that we know of). These are things that will be engraved in our memories forever.

However, now Hiroshima is a beautiful town famous for its sea food. Together with a colleague of Milica, Sasaki-san, we visited an oyster restaurant. This was the first time we ate oysters, and they were truly delicious. It is probably like Sasaki-san remarked: when your first oyster experience is with bad oysters you'll probably never eat oysters again, but when they are good you are hooked for life... Anyway, it is clear to me now that Annett and I fall into the first category... Just kidding! (I got you there!)

On the third and last day we visited the island Miyajima, which is famous for the floating gate, a torii that appears to be floating in the water. We visited beautiful shrines, parks, ate some udon with eel, and attended a monkey performance (we didn't know if we should feel sorry for him...). It was a wonderful experience...

Milica has written more about our Hiroshima experience at her weblog, and Annett has put out many more pictures on her new picture page.

Vocabulary Trainer: Granule

2006-12-27T19:49:00.000+01:00

Because I've been studying Norwegian and Japanese, I've spent a lot of time looking for the ideal vocabulary trainer. This proved to be a daunting task. Most of the 'free programs' on the Internet are 'share ware', which is not an option to me. This has nothing to do with that I don't want to pay anything, because usually the price is pretty low, but more with my hesitation (and often impossibility) of contributing back to a program that everybody has to pay for and can't look into the source code.

However, the biggest problems were no license technicalities. To create a decent vocabulary trainer is not a trivial task. I've been learning words for many years, and have always used computer programs to help me with it. During high school I learned my French and German words using a very simple program I had written myself. It automatically gave me a mark, and it motivated me to see my mark increase each time I went through a certain vocabulary file.

Now the problem is that there are tons of programs out there that implement the same basic features, and most of these programs are very nice (at least at first glance). After all, what can be so difficult about making a good vocabulary trainer? I spent months switching from program to program, some of them I used for weeks and some for just one minute. And most of them are good for the same thing as my program was good for: to memorize a rather short vocabulary list for a rather short time (e.g. the test of tomorrow). The problem with these programs is that they are not suitable for creating and maintaining a large vocabulary over time: They don't scale.

So how do you learn and maintain a list of, say, 5000 words? Obviously you can't just rehearse all words every day (which is what my program would ask you to do). The trick is to separate the words you can easily remember from the words that give you a hard time, and then rehearse the words in the latter category more often. Furthermore research has proven that to remember things we need to reinforce them, but only in increasing intervals of time. The German science popularizer Sebastian Leitner designed an algorithm that is easy to perform and does both these things. It is called the Leitner-method, and learning about its existence was definitely an eye-opener for me.

Half a year ago I finally found a program that made me stay with it. It is called Granule and written by Vladislav Grinchenko. It is a wonderful program, and has all features I could wish for:

It is free software (GPL).

Granule implements a Leitner based system where you can choose your own parameters.

It is ported to GNU/Linux, Windows NT/2000/XP, the Nokia 770 Internet Tablet, and the Sharp SL-5500 and the like with GPE image. If you own one of the latter two portable devices you can train your vocabulary in the train, bus, plane etc.

Its vocabulary files are encoded in Unicode. This is essential for learning exotic languages (like in my case Japanese), and therefore for the "general purposeness" of the application.

If you have a sound dictionary is installed, you can let Granule pronounce the words you are learning.

Open Office macro's for printing. You can export your vocabulary to flash cards that you can use on the road.

It can automatic schedule for you, keeping you on your toes and preventing you from slacking of.

You can easily import vocabulary from Comma-Separated Value files.

Vocabulary entries can contain several answers and an example sentence.

Our Tokyo clubbing experience (revisited)

2006-12-22T15:58:00.000+01:00

I meant to post this much sooner, but... Whatever. I should stop starting each blog post with an excuse.

Milica, a friend of Annett and me who also works in Tsukuba, has written a piece about our clubbing experience. Also check out the action pictures.

Visiting Kyoto, Nara and Osaka, and clubbing in Tokyo

2006-11-26T13:06:00.000+01:00

It is nice that Annett and I both write about our experiences here in Japan, because it takes half the amount of time! (Sure thing, Captain Obvious...)

Anyway, Annett has written about our trip to Kyoto, Nara and Osaka (here are the pictures) and about our clubbing experience in Tokyo (here are the pictures)!

Four days in Seoul

2006-11-25T12:08:00.000+01:00

Although I attempted for several months to get a visa in Japan, I didn't manage. Japan is rather strict about who they let into the country, and my unofficial status as a "university guest" wasn't helping. With a regular tourist visa I was able to stay in Japan for just 91 days. However, Annett and I had planned to stay until Christmas, a total of 107 days. Instead of shortening our stay, we decided to leave the country for a couple of days. Since Japan is an island, and since boats are slow, we had to fly our way out of there, and so we flew to the nearest country we could easily get into: South Korea.

More precisely, our destination was Seoul. Although Seoul has yet to acquire the touristic status of for instance Bangkok, it has (almost) all the facilities we could wish for: most people who make a business speak at least half-decent English, and at most touristic cultural sites, like for instance the palaces and the Korean Folk Village we visited, there were either English speaking guides or boards with English explanations.

We managed to find a room in a small family run hotel called Yims House (half of the Korean population is called Yim), where we had our own bath room with bath and shower. Furthermore, we had a television with about 80 channels, including the hilarious American Air Force National channel, and this provided us with the perfect way to relax after a long day of sight-seeing.

In the limited amount of time we had, we were able to see quite a few interesting things, partly because the staff of the hostel was?? so friendly to give us some tips about what we should see and what was not very interesting. We visited, for example, four of the five palaces situated in Seoul. These were very beautiful and interesting, but we had seen similar things in Japan. On the other hand, visiting the Korean Folk Village was a unique experience. It was amazing to walk around in a reconstruction of a medium-sized city and see, no feel, what life was like for a Korean in the 19th century.

Again thanks to the staff of the hostel, it came to our knowledge that there was the possibility of taking a DMZ tour (DeMilitarized Zone), a trip to the border between North and South Korea. This turned out to be one of the highlights of our trip to Seoul. With the goal to quietly attack South Korea, North Korea dug several tunnels under the border. Four of these have been discovered, the first of which in 1978 and the last in 1990. And at our DMZ tour we were able to enter one of these tunnels!

Our tunnel was discovered because an engineer from North Korea had managed to flee the country, together with the knowledge that North Korea was digging such tunnels to attack South Korea. To detect these tunnels, South Korea put water pipes in the ground at many places. When the North Koreans used their dynamite to construct the tunnel, one of these pipes blew up and as a result water flew up in the air (or something like that...). When they found the tunnel, the North Koreans claimed it was one of their coal mines (apparently they had accidentally ended up under South Korea). They had even gone through the trouble of painting them black! Unfortunately we were not allowed to take any pictures inside the tunnel.

Altogether we had a very interesting experience in Seoul. It is definitely a comfortable and cheap city to visit, although four days is, naturally, too short. Something we really noticed was the gap in attitude between the younger and the older generation. Starting at what we think is the age of 55, people become a bit impolite, pushing you for instance aside to get into the metro, and almost all older men give Annett a long, animalistic sort of look, even turning their head when passing by (this is something we also experienced in Romania, but then by mainly the younger men). Apart from this, we had a great time in Seoul.

For more pictures, look at Annett's picture page.

Kabuki and yakitori

2006-11-21T14:09:00.000+01:00

As usual, this weblog - and Annett her weblog as well, admittedly to a lesser extend - is outdated. I had completely forgotten to write about our trip together with Edwin and Sjoerd to Kabuki, traditional Japanese theater. Thanks to a headset and an English translation, we were able to follow the story line and learn a thing or two about Kabuki. For instance, Kabuki is not as much focussed on realism, as western theater usually is, as on beauty and perfectionism. It was a very interesting experience, and I would go again if I would have the chance. Unfortunately we were not allowed to take any pictures inside, but we were of course allowed to take a picture in front of the theater.

Here is a nice picture of the four of us in a yakitori place, I believe from the night before they returned to The Netherlands. (Notice the cool, typical handwritten menu hanging on the ceiling.)

Biking in Japan

2006-11-20T14:17:00.000+01:00

Just when Annett and I came back from Seoul, Joost payed us a visit. After finishing his studies in mathematics, he had been travelling for two months through China and Thailand. Now he came to Japan to visit his host family, with whom he had lived nine years ago for a whole year by means of an exchange program, and of course the guy he used to bike with. After biking through Germany and Poland last year, we planned upon going on a biking trip through Denmark. This never happened, because by then I had moved to Oslo to live together with Annett and started working on my PhD. Life is what happens to you while you're busy making other plans... :)

When it turned out that we would both be in Japan around this time of the year, it was only natural to consider a biking holiday in Japan. With almost all preparation done by Joost - I had neither a madras nor a sleeping bag when I left home - we went to Hikone, a small city located near the to pick up our bikes.

Starting our journey at the Biwa lake turned out to be a great choice: there was not too much traffic, it was flat and beautiful. Later on the day we had to climb a small mountain, and we encountered our first tunnel, something Joost had been warned for in a book he was reading in which a woman describes her experiences of her biking trip in the land of the rising sun.

Facing the tunnels definitely belonged to the darker parts of our trip. Usually there are no separate biking roads, and cars and trucks are not allowed to pass each other. Of course they are always willing to make an exception for those annoyingly slow bikers, which is nearly impossible and therefore rather scary. Sometimes there is, however, also the possibility of biking on the side walk, but because of 60 centimeters of luggage on the back, these 80 centimeters of sidewalk leave just 80 - 60/2 = 50 centimeters to balance oneself while being passed by trucks. Furthermore, inside such a tunnel a scooter sounds like a truck, and a truck sounds like an airplane, and I can assure you that you feel slightly pressured if an airplane is chasing your hiney. Needless to say that we felt relieved each time our carbon coated faces finally saw the light at the end of the tunnel...

More than at any of the previous biking trips we camped at some peculiar places. With its 130 million inhabitants, most of Japan is highly cultivated. This makes it difficult to find a spot to put up a tent that is not too much in sight. The first night we found a particularly nice place: a small park next to the Japanese sea! Parks are very nice, because there is usually a public toilet (these are pretty clean in Japan). The second night we again ended up in a park next to the sea. However, because it had become stormy and rainy weather, we slept that night in a three by three meter handicapped toilet: big enough to put inside both our bikes and put up our tent to prevent us being bothered by mosquito's! Obviously we were able to lock the toilet, thereby keeping the local schizophrenic outside (and here I was wondering who this guy was calling to all this time...). The third night it was again very bad weather, and the best spot we could come up with was a shed of an elementary school. (Personally I think Joost went a little bit too far the forth night, when he camped under the entrance gate of that Shinto shrine...)

On the third and last day of our biking trip we had very bad weather, so we were kind of forced to use the train. In Japan you officially need a special bag around your bike when you want to take it with you on the train. Since they were supposedly rather expensive, we had never bought these bags. We first wanted to make sure if these bags were really necessary. Joost even tried it the sentimental way: "But we don't have such bags..." However, the ticket clerk disappeared and came back with a board on which the rule was written, as if to show that it was really impossible since it was written on a board. Anyway, we decided to construct our own bag from a some garbage bags and a roll of tape. The result was disputable, but, in any case, it enabled us to take our bikes on the train.

When we got of the train, I experienced an embarrassing moment. We had to carry our bikes, wheels and all of our bags of the train, and since we stopped somewhere in the middle of nowhere, this all had to be done in limited amount of time. When I finally carried the last bike of the train, the door closed and I was stuck pushing with all might to keep the door open: according to the looks of it a stalemate allowing neither me to get of the train, nor the lady who had been waiting all this time get on the train. Fortunately I managed to squeeze out a short "haite kudasai" (please come in), and the lady crawled under my arm into the train and I jumped of the train with my bike...

At this moment the rain was still pouring down and we got completely soaked biking the last ten kilometers to a touristic spot that is famous for its onsen (hot springs). We left our bikes and luggage at an elementary school, ate some delicious udon (big Japanese noodles), and visited a hot spring that was praised in the Lonely Planet. On our way we met hundreds of Japanese walking around in yukata and on their geta, which was a pretty remarkable sight. The onsen was absolutely wonderful, and I recognized some things I had seen in anime before, like the typical cleaning seats and the towels they're wearing on their head. After biking for three consecutive days we could really appreciate the healing and cleansing of the onsen. We stayed inside for about two hours, which is of course way to long for such a hot bath...

When we walked back to our bikes we met a Japanese man in his sixties, who invited us into the bar we were standing in front of. We had already been hearing some interesting vocals coming out of the bar, and we were keen to find out what was going on. Once inside, we saw a whole group of tipsy Japanese men in their sixties, dancing around in their yukata while singing karaoke (yes, Joost has some movies of it...)! It turned out they were all coming from the same neighboring town and now had "an evening with the guys", while their wifes were doing other things. Needless to say we had a great time talking to them and doing some karaoke songs ourselves! They kept on giving us drinks and snacks, and in the end of the evening the bar lady made us some onigiri (rice rolls) and some Japanese green tea. We got to practise a lot of Japanese, and for me it was a great way to end our biking trip.

Joost has many more cool pictures (tunnel, onsen, swimming in the Japanese sea etc.), but I can't reach those right now. So more later! :)

Update: Joost now has also written a piece about the biking trip on his weblog.

Firework festival in Tsuchiura

2006-10-17T00:01:00.000+02:00

About twelve days ago two of my Dutch friends visited me, Edwin and Sjoerd. Together with them, we experienced some funny trips, and what I'm about to tell you is one of them. Annett has written about our trips to Kamakura and to Akihabara and Asakusa on her blog.

On Saturday we visited together a huge fire works festival/competition in Tsuchiura, just 15 kilometers to the North-East of Tsukuba. It was supposed to start around 18:00, but when we came there at 16:00 it was already crazy. We read somewhere that almost a million Japanese gather here every year to attend this big circus. When we stepped out of the bus, we were, like on most Japanese publics events, greeted by the many stands with yakitori, yakisoba, chocolate coated bananas and all kinds of sea foods. After walking around about an hour, we finally found a decent place to sit down that was close enough to the toilets, because we wanted to drink some beers.

Actually the first thing I did was going to the toilet, because at that point the queue was only a couple of meters long. This is obviously not very long for five toilets, especially not if you take into account that they had to do for the circa 1,000 people we shared our field with.

When I came out again I must have done something wrong, because the wind blew it shut and it locked itself, and then there were only four toilets left for the whole field. Nice one, monsieur George. However, I did my duty. I informed the nearest police agent, who, as a consequence, started a series of attempts to pick the lock. When I saw him taking care of it I got myself the hell out of there, thereby escaping the slightly unfriendly eyes of the people in the queue.

Unfortunately, it didn't seem entirely trivial to pick the lock, because after several attempts the police agent gave up. Apparently not realizing the scope of this, he did also not inform the rest of the crew that we had a situation here and didn't call for the necessarily backup. Evidently, the number of toilets per human was carefully calculated in Japanese units, not incorporating slight deviations caused by clumsy Dutchmen: we could see the queue grow by the minute.

At this point I started to get slightly paranoid, and had a creepy feeling that the 1,000 Japanese were all talking about that annoying foreigner that managed to lock the toilet from the outside. Luckily Sjoerd was willing to stand up and take some pictures of the queue in my place, because I had made myself as small as possible. Of course most Japanese had no idea about what was going on, and we saw Japanese people knock on the door and listen what was going on in there all the time...

On top of that it started to get very cold, and we had, once again, not taken enough clothes with us. Moreover we were worried about how we would get back, because at some point the million Japanese would want to use the same roads as us (we couldn't go by bike, because Sjoerd and Edwin didn't have a bike here). We therefore decided to leave at 19:30, half an hour before the end of the fireworks. After waiting half an hour at a bus on Tsuchiura station, we decided to take a taxi, being assured by the taxi driver that it was not impossible to get to Tsukuba. We got, however, completely stuck in the traffic, and we had to pay the taxi driver, get out and walk back to the station. There, as luck would have it, we were just in time to catch a bus that went to Tsukuba.

We understood that this was going to take some time (and we all had to pee so badly...), so we sat down on the floor of the bus - not a very Japanese thing to do :). An old Japanese man had sat down beside me. Just when Sjoerd en Edwin were bad mouthing the Japanese in the bus for not standing up for this man, the man collapsed and didn't respond at all anymore. This was very scary, I thought he had died just there next to me. Panic in the bus, the bus stopped aside of the street and opened up its doors. When his family tried to drag him out, he all of a sudden stretched out an arm and responded again. Probably he just lost his consciousness, but it might also have been something worse. They called an ambulance and the bus was on its way again, and we arrived, after a bus trip of an hour, finally in Tsukuba. I had an enormous headache when I came home...

For more pictures, see Annett's picture page.

Biking to Buddha

2006-10-16T01:35:00.000+02:00

Already a couple of weeks ago we went out to bike to visit a Buddha statue that was located quite some distance to the South-East of Tsukuba. It is a huge statue, for we were able to see it all the way from Tsukuba. Somebody at work had told Annett that it was quite a bike, and would take us at least one and a half hour to get there. Optimistic as we started off, we thought that if some random person could bike it in one and a half hours, we would definitely be able to do that in just an hour.

We started biking at two in the afternoon, spent some time in a Toys R Us store and arrived there at... 16:57. We had just three minutes left to buy a ticket and go into the Buddha to take the elevator up. We were too late...

Now here in Tsukuba it gets dark rather early, and also rather cold at night. However, since we would just be out for a couple of hours, we were just wearing a T-shirt and a top. On top of that, Annett believed that going the other way would be a short cut and save us a lot of time. To cut a long story short, it became darker and darker and we had no idea where we were. At some point we were really lost. It was completely dark, extremely cold, and we heard thunder in the distant...

We then biked back to a supermarket we had passed quite some time before, and asked the store attendant which of the four possible ways we should take; we had already tried two of them... At that point there was a very kind Japanese woman who asked us where we wanted to go. It turned out she was also heading in to the direction of Tsukuba, and she offered us to drive in her car slowly in front of us so we could follow her! This was an offer we couldn't refuse, and we biked - no we, raced - after her...

After 45 minutes of racing the car stopped and we were able to thank her for her kindness. We were on our map again, and about an hour later we were home again, taking a hot bath to warm up...

Dutch Voting Computer Easily Compromised

2006-10-06T04:57:00.000+02:00

In the Dutch television show "Een Vandaag" the we-don't-trust-voting-computers foundation demonstrated how to hack a Dutch voting computer to steal a pre-determined percentage of votes and reassign them to another party. This shouldn't really come as a shock, since similar problems have occurred and questions have been raised in for instance the USA and Ireland.

Earlier an episode of the television show "Radar" caused the SP party to ask the Minister of Internal Affairs questions about this. Minister Pechtold answered, however, that he didn't see any reasons not to trust the voting computers. Don't you get outraged by this?

In my opinion the real problem is here the use of security through obscurity, and the myth that this is safe. For me it is just another example of a drawback of closed source. If open source would have been used, such obvious flaws would have been found way before. Who can say for sure that our past elections haven't been manipulated? Can our government please wake up?!

Google Reader

2006-09-29T03:53:00.000+02:00

For anyone who doesn't read the blogs of his friends: there is no excuse anymore. Today Google published a completely revised version of their Google Reader. Although I was already happily using the old version, this version is much and much better. In my opinion feed readers are a piece of web technology everyone should use, just like e-mail. Just invest that 30 minutes of your time to check it out, and live happily ever after.

Life in Tsukuba

2006-09-26T10:11:00.000+02:00

Today it is exactly a month ago that Annett and I arrived in Japan, and it is about time that I tell you what it is like here in Tsukuba. All the pictures are, however, from our trip to the Imperial Palace in Tokyo.

Easy life

What I probably like the most here in Tsukuba, is that life is so simple. Last year I had many things to arrange and was mentally exhausted when the summer holiday finally arrived. Here in Tsukuba, however, each day is uncomplicated. On a typical weekday I get up at 7:00, shower, have breakfast, do one and a half hour of learning Japanese, work for 7 hours, buy together with Annett some food at the supermarket or go to a noodle place, and have a relaxing evening. Practically no administration, and the only thing we have to arrange is which place we are going to visit in the weekend.

Our apartment

We have a fantastic apartment here. In contrary to what one would expect near Tokyo, it is about three times as big as the place where we used to live in Oslo. Furthermore it has air conditioning, internet, a washing machine, a modern Japanese toilet and everything else we could wish for, and more. As the land lord explained to me, the Japanese are gadget minded people. :)

Tsukuba

Tsukuba Science City is a planned city, officially founded in 1987, that is home to more than 60 research institutes and of course the University of Tsukuba (where I'm a guest). It is a very pleasant, rather western city where everything is within biking distance. This is nice, since we were able to rent two bikes here. Its construction is ingeniously. The biking and shopping streets are on higher grounds and connected by air bridges, eliminating the "car factor" and enhancing the inner city feeling, while still easily reachable by car. After biking around a little bit, I discovered a road over these platforms leading, through parks, all the way to the University of Tsukuba with only one traffic light. It's a very nice place to go jogging.

Public Transport

As of 2005, there is the very rapid Tsukuba Express that takes you within 45 minutes into Akihabara Station, almost in the center of Tokyo. It leaves from under the bus station (underground), therefore not bothering you at all. The public transport in Tokyo is really amazing. Each day, about twenty million people use this system to travel within Tokyo, and it is extremely efficient. Despite its scale, it is very easy to understand. Even for a foreigner. I wish we would a system like that in Oslo...

The Japanese People

The Japanese are the kindest and most polite people I have ever met. Since one week before we came to Japan we were still in Romania, the culture shock was even bigger. We've had people stopping their car to give us directions, just because we looked lost, and coming after us again to give us extra help. When we went out biking to the middle of nowhere, getting terribly lost when it got dark, somebody led us home by driving in her car very slowly in front of us. I will write more about that in another post. :) They are all amazingly nice, and I doubt if we ever want to leave this place...

For more pictures, see Annett's picture site.

'Hypoallergenic cats' go on sale

2006-09-26T05:25:00.000+02:00

According to BBC news, 'hypoallergenic cats' go on sale. That's great, now we can also have a cat! 4.000 dollar is still a little prizy though, but it might go down pretty fast.

News from Tsukuba

2006-09-24T01:54:00.000+02:00

Yes, I'm still alive. I know I am being lazy, but Annett has written another piece about Tsukuba. Very soon I am going to make a post about what we do here, and that's a promise.

The Goonies Remake is Finished!

2006-09-03T16:04:00.000+02:00

In a previous post I wrote to tell you that Brain Games had started to remake The Goonies, one of my favourit MSX games. Three days ago they finished and submitted the result for the Retro Remakes, The Big 2006 Compo. The result is amazing and a must-play. It is released under the GPL and there are Windows and MacOS binaries available. Check it out on The Goonies Website.

First Week in Tsukuba

2006-09-03T16:00:00.000+02:00

Annett has written about our first week in Tsukuba. If you're interested, check it out!

Timo

2006-08-30T10:18:00.000+02:00

Yesterday morning I received an e-mail stating that somebody I knew rather well has committed suicide. He studied computer science, and since he was a student assistant as well, we shared the same office space for several years. The moment I read the e-mail I was shocked, and shortly after I became very emotional. Since then I have been thinking about him and things he said all the time.

Most of us saw that he had been feeling down for a long time and didn't get much sleep, but no-one of us thought he was this depressed. And we didn't know how to help him either. Now I'm wondering if there is anything we could have done about it if we would have understood his situation better. Maybe if he had gotten some professional help, I don't know.

Yesterday was the funeral, but I couldn't be there since I am in Japan right now. I have a lot of happy memories about him, and will remember him as a very kind, funny, gifted person that was always there to help other people out. I just wish somebody could have helped him too...

On Holiday in Croatia

2006-08-24T23:05:00.000+02:00

Two weeks ago Annett and me returned from a holiday to Croatia and Romania. Below I've written something about the things we did in Croatia that I hadn't come to to put on my blog yet. Annett has written the part about Romania, and we will add pictures later.

Since we had so many things to arrange this year, we didn't find the time to acquire some background knowledge about Croatia and Romania, which always raises the appetite when going to a certain new country or region. While we were there, however, we were able to pick up some nice things about the country.

The Culture

If we forgot for a second about the omnipresent mysterious one meter high stone walls, the island seemed rather unused. Later we would hear that all this land was used for thousands of sheep, which we weren't able to see since they were all inside because of the high temperature. When Annett and me visited the town Pag, we bought an overpriced sheep cheese that we ate heartily at a bar with red wine.

Another interesting thing was the Croatian language. The language belongs to a language group, the South Slavic Languages, I didn't know anything about, and therefore almost everything was gibberish to me. According to Mateusz, who was born in Poland, it is in many aspect very similar to Polish, which belongs to the West Slavic Languages. Just like Polish they have some words consisting of just one consonant, and there are some very nasty diacritics.

Cheap

With the help of Sanja, a friend of ours who was born in Bosnia and lived a year in Croatia, we rented an apartment on Pag, one of the many islands of Croatia. This costed us only 1000 kuna (137 euro) per person per week! For the same price a taxi driver was willing to drive all nine of us all the way from Rijeka Airport to our apartment, which was at least a two-our-drive; it was much faster and much more pleasant than traveling by public transport. For half a liter of beer we usually payed around 15 kuna (2.06 euro) and for a full dinner around 75 kuna (10.28 euro). For a huge burger one pays around 20 kuna (2.75 euro) and for a plate of freedom fries around 15 kuna (2.06 euro). This is all, especially for Norwegians of course, very cheap. Liter bottles of mineral water in restaurants are, however, heavily overpriced and cost around 30 kuna (4.11 euro).

Beautiful

Croatia has a lot of wonderful beaches, and the sea has the typically Mediterranean blue/green color. On the mainland starts almost immediately a huge mountain ridge that adds a surreal look to the whole picture. At one of the beaches there was, during the day, a party similar to MTV Beach Party going on, and this was hilarious to look at. Since the sea was very clear, I decided to buy myself a pair of flippers, goggles and a snorkel. Because I'm experiencing some problems with my right ear, I was not able to dive very deep, but it was certainly of fun to swim among and chase the fishes.

Just before we came, there had been some bad weather, so we were lucky the temperature was way under 40 degrees Celsius. However, during the week it went steadily up to 40 again, making being around the water a necessity. Some of us got heavily sun burned, but I'm luckily not one of them. It seems that the sunscreen we bought - accidentally with glitter - saved me.

The last day in Pag we went on a boat trip to two other islands where it was very exciting to snorkel: very deep and full of fish and other sea creatures. On our way back we saw a dolphin swimming far away and when we came close to it, it used the slip stream of the boat to swim along with us for a while, until it decided to go its own way again. The crew told us that they saw this regularly, and that the dolphins would stay longer if encountered in a group.

Crazy Traffic

The traffic here is full of crazy people. Without any hesitation, people make a turn right in front of your nose. The other day, when we were driving in a bus, someone parked his car in the middle of the road to block the bus and all other traffic, and two people jumped out begging the bus driver to take one of them along. Yet, instead of calling the police, the bus driver let this maniac in and continued his tour as if nothing happened. At such a moment it is convenient to speak some Norwegian, enabling Annett and me to safely express our uneasiness about the whole situation...

Bike Trip

Because the island was rather flat, we decided upon going on a bike trip, inspired by the many flyers we say that advertised a bike rental place. When we, after a one-and-a-half hour walk finally reached this place, they turned out to have just three bikes available. To get rid of our frustration we settled down at a restaurant to eat lunch and have some drinks, and started walking home afterwards. We may not really have felt like walking, because at every other bar we encountered, we stopped to have a Mis Mas, what seemed to be a mix of Fanta and red wine. After a couple of Mis Mas'es we came to the conclusion that this was the best biking trip ever! At a certain point we started to see more and more naked people around us, and in retrospect this might explain the annoying wall we had to climb over to continue our biking trip: we had arrived at a camping for nudist. Despite our clouded state of mind, we decided not to bother them anymore and got ourselves out of there. This must have been the moment that we seriously started using the name of our group The Swedish Nine, which we chose carefully in order not to embarrass any of our own countries.

It has been a wonderful holiday and we managed to get some rest here. Annett saw to it that I didn't take any mathematics with me, although I did manage to take my Japanese study book Genki with me. We were about to go to Japan, and we wanted to be prepared...

PhD position in Oslo and holiday!

2006-08-02T15:54:00.000+02:00

Good news, everyone. That the title announces both my new job and an upcoming holiday probably indicates that I should write more frequently on my blog. Some weeks ago I started at my brand new and first real job: a PhD position at the Center of Mathematics for Applications (CMA) in Oslo! The topic will be in the area of algorithmic aspects of algebraic geometry, probably again in connection to differential equations. For my master thesis, my supervisors and I did research concerning the classification of the first order differential equations with the Painlevé property, and this was rather pure, as in not applied, mathematics. After my master thesis I realized that I wanted to switch to a slightly more applied topic, and therefore I am very glad to work for the CMA.

Although I will go to Japan in three weeks, I only just now officially moved to Norway. We sold and completely moved out Annett her apartment and now I am, only officially of course, living at her parents' place, with even my name on the mail box. This caused of course some very curious looks from the neighbours who were wondering who this new family member might be :D. I have obtained a letter stating that I can stay here until 2011, and later I will receive an official ID card. Furthermore I obtained a temporary D-number (national identification number), a bank account, a tax card and I applied for a permanent identification number. Norway doesn't seem to be very bureaucratic, because I was able to obtain all these documents in a holiday month. Having a job greatly simplifies the whole procedure.

Upcoming Saturday Annett and I will go on holiday to Croatia with a couple of friends, and after that we will attend the International Conference of Physics Students (ICPS) 2006 in Bucharest. For us this conference of course has a very special meaning, because in 11 days it will be exactly a year ago that Annett and I met at ICPS 2005 in Coimbra! Because we had a rather busy year, Annett and I decided to participate only passively in this conference, so no presentations or physics shows coming from us this year. We return to Norway at the 22nd of August, and then, four days later, we will be on our way to Japan...

Hiking together in the forest

2006-07-07T19:38:00.000+02:00

Oslo has it all. In the winter we live 15 minutes away from a place to ski, and in the summer we live 15 minutes away from a huge forest with beautiful quiet lakes and cozy streams.

Friday Annett and I left in the early evening to go camping in the near forests. The first day we camped at a small and quiet lake, just fifteen minutes with the bus and a ninety minute walk away of our apartment. There we swum and made sausages on our one-time grill. Apart from the mosquito's, it was a wonderful evening.

The next day we walked up to a much bigger lake. There we put up our tent on an island that was connected to the 'mainland' by a couple of tree trunks. Later Klaus, Ingvild and their very cute Labrador Balder joined us, and even later Kanutte and Tor-Helge as well.

Altogether it has been an invigorating weekend. We had a very cozy time swimming, playing with Balder and making fire and food. Hopefully we can repeat this one more time before we go on holiday to Croatia.

Belgium Government Requires Open Documents

2006-06-26T22:19:00.000+02:00

Good news, everyone. The Belgium government has decided upon banning closed document formats from their office documents, starting in September 2008. Norway and The Netherlands can learn from this. Way to go, Belgium!

Source: Overheid bant Microsoft-documenten

The Goonies Remake

2006-06-25T18:27:00.000+02:00

On a previous post I expressed my gratitude for a remake of the MSX game The Maze of Galious by Brain Games. In the end of the post I wished there was a remake of the popular MSX game The Goonies.

Now some wishes are granted, because Sunday I got an anonymous reply at my blog post, urging me to look at the Brain Games' Forums. There I found out that they started working on a remake of The Goonies about two weeks ago for the Retro Remakes, The Big 2006 Compo. Great, check it out!

Diploma Ceremony

2006-06-22T14:07:00.000+02:00

The post is a little late, but since it would be inappropriate to leave it out:

One Laptop Per Child

2006-06-03T19:51:00.000+02:00

…My heart’s in Accra » It’s cute. It’s orange. It’s got bunny ears. Ethan Zuckerman has a great, in-depth look at the One Laptop Per Child program.

World maps and their topology

2006-06-02T17:59:00.000+02:00

An idea that has been wandering around in my head for a long time is the creation of world maps living on top of an interesting 2-dimensional topological varieties. Most games have a world map that is a rectangle (topologically a disc), and there might be some world maps that carry our own earth's topology of a 2-sphere. These are rather boring varieties, and it would be interesting to allow for worlds with more exotic topologies: For instance the topology of a torus (the surface of a donut) or even of objects with a higher genus (the number of holes, so the torus has genus 1). The classical pacman game in which the top & bottom and left & right are identified is the torus.

One can triangulate such a variety in order to obtain a decomposition in tiles. Locally, on the player's screen that is, part of this world would then just look like a square as usual. But when walking/driving/flying around in one direction, you can end up at the same place (leaving the player puzzled ;) ). Part of the gameplay would then be understanding the world map and in particular its topology, allowing for more complicated mazes. It would be interesting to carry over some of the phenomena of topology to such a computer game (identifying, cutting), thereby surprising the user now and then.

One advantage of keeping a strict structure in the topology rather than inserting some portals here and there is the superior ability of NPC's to deal with it. Another advantage is the possibility to visualize the topological phenomena in a spectacular way (for example identifying two worlds with each other in a point and then smoothly stretching this identification to a bigger area).The concept could also be generalized to 3-dimensional varieties for 3-dimensional "shoot 'm ups" (like for instance Descent). For three dimensions the phenomena get even more exotic. Why always make the same game, if one can do spectacular things without much extra effort?

Proposal for a Guided Book Reading Web Application

2006-05-27T11:52:00.000+02:00

Introduction

When I came across an online chapter of a book, in which footnotes are added to words, with a translation of these words in the margin, I got the following idea.

Wouldn't it be nice, if there was a web application that takes a text from, say, Project Gutenberg or Wikisource, and then creates such a margin automatically? For this one needs to know for each word how difficult it is or how early it should be learned. This could be edited manually. One could then also specify the difficulty, by setting a threshold parameter called minimal difficulty. A next step would be to include sayings and the like, but this is of course much more difficult and not really necessary.

Before I want to start implementing it, I would like to have some feedback from other people.

The Texts

First of all there are several questions we need to ask ourselves concerning the text.

What should the format of the text be? It is hard to start from an unstructured text and many texts are in HTML, therefore it might be a good idea to start from HTML/XHTML.

Examples of interesting free texts can be found at:
1. Project Gutenberg: contains many documents in HTML, ASCII and Plucker (probably the biggest and therefore the most interesting). Also Project Gutenberg can be downloaded as a whole, which gives us the possibility not to use too much of their bandwidth.
2. Wikisource: contains quite some documents in many languages, but the text is rather unstructured.

Rated Word List

There are different approaches to make a rated word list, and here I shall discuss the one that I think is the best.

Rather than using a word list based on frequency, it is better to make the system for a rated word list by hand. A list of frequencies is not precisely what one wants. What one really wants is a rating that tells you how early you should learn the word. Because a list of frequencies is static, it does not leave space for improvement. When one rates every word by hand the list will gradually improve. Moreover different people can rate, and therefore a combined averaged list will represent a general opinion. Furthermore it is not that much work to get the most important words rated, especially not when one does it while reading.

My idea is the following: We make a scale from 1 to 10, in which 1 corresponds to the words one should learn first and 10 to the most unused words. For each number we then make a list of sample words that can be used as a reference, for instance in the English language:
1. the, a, an, it, ...
2. before, under, after, because, ...
3. etc.
There is also the possibility of putting all articles in category 1, all prepropositions category 2 etcetera, thereby simplifying deciding for some words in which category they belong. Of course I chose the number 10 rather arbitrary here, anyone a better suggestion?

There might be an advantage in keeping user-accounts with user-rated lists. A general rated list can then be formed from these user-rated lists. Furthermore each user can keep track of a list of words that might have a very rating but that the user just happened to know. If translations of these words just keep showing up, then the user can remove this redundant information by adding them to his known-words list.

Sometimes a word might not be in the dictionary. Then we can show the word in red and give the user the opportunity to either add a translation of the word to the dictionary (and give it a rating), or add the word to the known-words list.

The Dictionary

This section has contains some thoughts about what kind of dictionary we can use and where we can find it.

It would save some work in making the rated list if would find a way to deal with the morphology of words, that is the different forms of verbs, the adjective-adverb by adding or removing 'ly' etc. The key thing is here to identify a group of words that, due to some abstract grammatical relation, necessarily must have the same rating. The best thing would be a dictionary that has this information, and helps in this way identifying words with a different form.

We can use several dictionaries at the same time, since we'll digest them into a word list with translations (and morphology). For each dictionary we can write a separate harvesting program.

There are several things we are looking for in the dictionary:
1. It should be possible to digest the right information from it. That is, word translations and possibly morphology.
2. It should be free, allowing us to use it.
3. It would be nice if it supported many languages.
4. It would be nice if it was relatively complete.

Possible dictionaries are:
1. Wiktionary
2. Loco
3. Dictionaries on Gutenberg

The Screen Layout

In this section I want to discuss the layout of the screen. This is important because a reader will spend a lot of time looking at it.

We need the following elements on the screen:
1. Text block: a block with the foreign text that we want too read.
2. Translation block: a block containing the translations of the difficult words.
3. threshold field: a field in which the user can specify the desired threshold.
4. Dictionary/language button: a button where the reader can specify the language of the text.

We need the following elements in a pop-up edit window.
1. Sample words block: a block containing sample words to guide the user while choosing a category.
2. A rating field: a field in which the user rating of the word can be specified, together with the common rating.
3. Translation field: a field that contains the possible translations of the word.
4. Isknown field: a field with a boolean value that states if the word is known or unknown to the user.

Should we go for a dynamic or a static layout? That is, should the user decide where to place the blocks? I don't think this is necessary, because there is a small and fixed number of blocks.

The text block should be rather narrow for easy reading.

If the text in the text block is chopped up into pages that fit on the screen, than it is easier to read, and will also make sure that the text and the translations won't start to walk out of line. On the other hand it is much easier to make a layout that does not chop the text up in pages. Therefore I propose to start with the latter, and change to the former when everything works.

The words with rating higher than the threshold should be marked with a 'footnote,' a number in super script. This won't be too distracting and links the words with their translations.

We have several different types of words occurring in the text. This is a proposal for distinguishing between these words (see the picture):
1. Unrated words that appear in the dictionary (gray).
2. Unrated words that don't appear in the dictionary (gray, underlined).
3. Rated words whose rating is lower than the threshold (regular).
4. Rated words whose rating is higher than the threshold (footnote).

The block with sample words in the category can be placed in a pop-up, thereby only showing them when it is necessary.

The following picture shows a proposal for a screen layout.

General Remarks

There are some general remarks that I would like to make.

For the accessibility I want it to be a web application. Does anyone have an idea what programming tools would be suitable? Do I hear AJAX?
It might be rather easy to make printable PDF-versions, by exporting to a TeX-file that adds the translations as footnotes at the bottom of the page. This of course misses the dynamical options of rating words and changing the threshold on the spot, but might serve as a prototype while 'getting things work.'

We could make a showcase of books that have been read thoroughly before, and therefore have no unrated and unknown words and maybe an audio file.

Gutenberg also contains many human and computer read audio books. We could, for such books, add a button which allows one to read and listen at the same time.

It might be easier to start with an English language and dictionary.

If this idea would get very popular, people might submit their own texts. These could, in some cases, be sent to either Project Gutenberg or Wikisource. More importantly, translations of words in the dictionary could be sent back to the dictionaries we use.

A Road Map

In this section I want to propose a road map that will lead to a fruitful product in the end, but also gives us something working in the beginning.

A version in the English language that exports to TeX.

A web application that doesn't permit changing the dictionary, changing the threshold, adding a rating, doesn't chop up the text into pages

A web application that allows for changing the dictionary, the threshold, the rating, chops up the text into pages, adds a button to play an optional accompanying audio file from Project Gutenberg.

Questions

Several questions to get some input.

Which dictionaries are suitable to use?

Where can we find suitable online free texts?

Does anyone have a different idea of the screen layout?

What is the language in which the application should be written?

Is there anything else we need to ask ourselves?

Abel Prize

2006-05-26T11:45:00.000+02:00

The Swedish mathematician Lennart Carleson received the 2006 Abel Prize from Queen Sonja at an award ceremony in the University Aula in Oslo 23 May. The Norwegian Minister of Education and Research Oeystein Djupedal also attended the event.
One can read more at the website of the Abel Prize.

The Abel Prize is a famous prize in mathematics, in some sense the runner-up of the Fields Medal. On Tuesday I was at the Abel Prize ceremony. It was rather formal and I was afraid that the organization wouldn't let me in because I was completely soaked by the rain, but they were very nice to me. On Wednesday I went to the Abel Lectures, an interesting series of one-hour lectures about several topics connected to the research of Professor Carleson. Because the University of Oslo just happened to be at strike (nice timing), the schedule had to be changed somewhat to make sure not everybody would be removed of the building by the guards... I think the organization solved it very well by speeding up a little bit, thereby making sure everybody would be inside once the guards would come...

The Sound of Windmills

2006-05-21T16:09:00.000+02:00

In my first year, in 2001, I did a research project together with Joost Massolt, Derek Land and Herman Kloosterman. The goal was to measure in case of little turbulence how, near the ground, the wind speed depends on the height, how much sound windmills make at night and to establish a connection between these. This project was invented by Frits van den Berg, and recently he did his PhD dissertation in this area. Links and more details can be found at Joost's blog post.

17th of May

2006-05-21T15:40:00.000+02:00

Past Wednesday I experienced the national day of Norway, the 17th of May. On this day almost all Norwegians get their national costume out of the closet and go to the center of their local city. There they wave with Norwegian flags at the king and the queen. Those who don't believe me (which is very understandable, I personally didn't believe it before I saw it) can take a look at Annett's picture page. Annett wrote more about this.

In the afternoon we went, together with Klaus and Ingvild, to Kanutte and Tor Helge. There we grilled sausages and ate them with bread and lumpe, a Norwegian pancake (as I see it) made of potatoes. In the evening we played two games of Settlers. It was a great day.

Maze of Galious Remake

2006-05-14T10:39:00.000+02:00

When I was seven year old my parents bought an MSX. One of the games I used to play was Maze of Galious, Konami's sequel to Knightmare. Now I found out that some Spanish guy made a remake, and I'm hooked once again!

For the lazy Debian users typing apt-get install mazeofgalious as root suffices, but there is also a port for windows and a port for the mac. You have to download the data files separately though.

If you did not play Maze of Galious, you can find several other remakes at Classical Retro Games. I wish they made a remake of The Goonies...

Back in The Netherlands for Some Days

2006-05-12T17:29:00.000+02:00

There and back again. Wednesday night I returned from a short but busy trip to Groningen, where I stayed at my parents's place. Besides of being perhaps rather windy, the weather has been invigorating, giving me the possibility to bike back and forth to the university almost every day. At least my face and my arms are now not as white as they were ten days ago, and it even seems that my endurance is gradually increasing from a minimum in which it resided for several months. This was due to a persevering flu and probably also due to a high level of stress in all the things I was doing: finishing my master thesis in mathematics, doing the course evaluations, arranging all the documents for my PhD application, arranging my trip to Japan, moving to Oslo, learning Norwegian, etc. And of course the fear that one of these things wouldn't work out. Basically I am just very greedy.

When you are applying for a position you need to obtain many "official documents," that is, documents with a signature. Often things you have done in the past are not even taken into consideration if you don't attach something that makes it official. So one should figure out what documents one needs, and then try to get a hold of the people for the signatures. These people were very nice by the way, but I just don't really like to make so many requests...

Most important of all, I finished my master thesis. Last week on Wednesday I had the discussion with my supervisors, and on Thursday I subscribed to the diploma ceremony, which will take place the 12th of June, 16:30 at the Academiegebouw, Senaatskamer in Groningen. I am so glad I finally finished my thesis. It is written in the dirtiest TeX-code I have written so far. It doesn't even compile, because of more than twenty errors for which I did not have the time/patience to fix. Anyway, stubbornly ignoring all the error messages in pdflatex gave me the following documents: a pdf-file suitable for printing and a pdf-file suitable for reading on the screen. A preprint of a corresponding article is sent to Indagationes Mathematicae.

It was really nice to see my family and so many of my friends again. Twice I stayed over at Laurens's place so that I didn't need to bike back to my parents late at night. Together with Laurens, Edwin and Ramon we barbecued on Friday the 5th, the Dutch Liberation Day. That was really cozy. Monday I ate diner with Maarten and Johan, and Tuesday we ate diner and drank a beer with Wicher, whom I haven't seen for almost a year because he studied in Italy. Although it was really nice to see my family and friends again, I missed Annett a lot. It is good to be back home. In Oslo, that is. :)

FSF - Recordings from the 2006 Associate Member Meeting

2006-04-18T21:29:00.000+02:00

The FSF - Recordings from the 2006 Associate Member Meeting are available. It contains a bunch of interesting talks about DRM, and especially the speech by Eben Moglen is very interesting.

Poetry on Fibonacci sequence

2006-04-07T10:25:00.000+02:00

The rhythm is 1/1/2/3/5/8 :). From GottaBook: More Fibbery: "
Fibs,
Fun.
Clever,
yet simple.
How mathematics
and Poetry can blend so well."

An Idea for a Web Application to Learn a Language by Reading

2006-04-03T12:46:00.000+02:00

Since I moved here I started to learn Norwegian more seriously, and I've been reading a lot of Norwegian lately. When I came across an online chapter of a book, in which footnotes are added to words, with a translation of these words in the margin, I got the following idea.

Wouldn't it be nice, if there was a web application that takes a text from, say, Project Gutenberg or Wikipedia, and then creates such a margin automatically? For this one needs to know for each word `how difficult it is', and a measure for this could be a list of words together with its frequency, how often the word appears. These lists exist. One could then also specify the difficulty, by setting a threshold parameter called `minimal frequency'. A next step would be to include sayings and the like, but this is of course much more difficult. I guess it is just a day of work.

Saying Goodbye, Packing and The Big Move

2006-04-03T11:16:00.000+02:00

The evening after my talk I went out with a couple of friends to eat dinner in the `Kleine Moghul', a nice small Indian restaurant with great food, and afterwards I met most of my friends in `Het Paard van Troje', a cozy bar in the center of Groningen. My friends gave me some very nice gifts, including a DVD Laurens, Edwin, Ramon and Sjoerd had made me with a funny movie in which they said goodbye to me. It was a very cozy evening, and I really liked saying goodbye to them in this way (of course I am still coming back in May and April).

The next couple of days I spent packing my stuff, and made some arrangements with the new inhabitant. I sold him my fridges and a big closet for 110 euro, and I didn't need to paint over my GNU! That saved us a lot of time, which we didn't really have.

The last couple of days we ate dinner at my parents, together with my brothers and their girlfriends. Finally the day arrived that we should leave. Past Tuesday we woke up at 4:00, ate a little bit, said goodbye to my parents and at 5:00 we were on our way. We carefully avoided all traffic jams to arrive two hours early at the boat in Kiel. Once on the boat we first slept for two hours, and then went down to eat a little bit and play some chess, accompanied by some alcoholic drinks and a very nice jazz band. We had a wonderful trip and arrived at nine o'clock in the morning in Oslo. We spent the rest of the day moving in my stuff. I had finally moved to Oslo! (Annett wrote more on her weblog, and you can find more pictures on her picture page.)

Master's Thesis Talk

2006-03-24T23:47:00.000+01:00

Good news everyone, yesterday I finally gave my master's thesis talk. Also my exam program was approved (indeed, nice timing). I was rather nervous, but overall I think it went well. When Annett and I are back in Norway we'll upload some pictures. Here are the slides of the talk and a written version of the talk. The slides are made with the latex-beamer package, which is extremely easy and looks pretty good. Some people also asked me for the TeX-file. Now I just need to focus on moving to Norway and then on finishing my master's thesis. I already wrote the chapter about modern theory, which was the hardest, but still have a lot to write. That's what's going to keep me busy the next month...

News from Oslo

2006-03-05T21:32:00.000+01:00

Since last Tuesday I'm in Oslo again. There are a lot of things happening at the moment.

The most time consuming right now is the writing of my masters' thesis. I made a first version of the chapter called `Modern Painleve Theory´ (which is the hardest chapter), and emailed it to my supervisors for feedback. In just eighteen days, I'll have to give the final talk, and I'm already starting to get a little bit nervous about it. I haven't really started on it yet, but did make a start with the front page of my thesis. The idea is to take a part of the Riemann sphere, put pictures on it, and then draw a nice Riemann surface on top of it to illustrate the concept of a branch point. Indeed, just like Wikipedia. :)

Something else that has been keeping me busy is the arrangement of my four-month-stay in Japan. More precisely, I should say our stay, because I'm going there together with Annett. She's going to continue her Ph.D. research there, and I'm going to learn the language better and study some mathematics. I wrote to a Japanese acquaintance of my supervisor and he gave me the address of a lecturer at the University of Tsukuba. It seems this kind man is willing to accept me as a private guest on the university, enabling me to follow lectures and making use of the computer room, library, etcetera. This is great news of course! The next thing I need to do is get a letter of recommendation and try to arrange some money.

In Oslo it just stopped snowing, and the last couple of days we had some blue skies. Even for Norwegian terms, there is a lot of snow here now; it hasn't been this much in twenty years... Some cars can only be recognized by a bit snow that reveals the shape of mirror sticking out. Thursday I saw some guy using a shovel to create a parking place for himself.

By the way, Annett just set up her own blog. If you're curious, take a look. :)

Photo Stitches and Adventure Games

2006-02-18T12:21:00.000+01:00

On Laurens' blog I saw he had stitched several photo's together to generated QuickTime VR files, which give a view of 4pi steradians. He has some nice stitches of his room, the Zernikeborg and several other locations in Groningen. Might this make a nice three dimensional successor to the classical point-and-click Sierra On-Line adventure games, using locations from your neighbourhood?

Quick Review of the Last Two Months

2006-01-25T23:13:00.000+01:00

It's been more than two months since my last post on my blog. Why? I've been busy... and I didn't feel much like writing on my blog, of course. Just a matter of priority. It's nice to actually hear people complaining that I never wrote anything.

To catch up a little bit, I'll try writing down chronologically what, most important to me, has happened the past two months.

In the beginning of December Annett visited me, and we celebrated Sinterklaas with my parents. Here are some pictures. Be careful though, there are some pictures of me in my underwear there! I primarily worked on my thesis, and Annett prepared for an exam in electron diffraction theory. The last day we visited the Anna Frank house in Amsterdam. It was really nice...

In the end of December I visited Annett, and we celebrated New Years with friends. From Annett and her family I had gotten ski's as a christmas present, and we went cross country skiing a couple of times. That was really nice, and much harder than I had expected. After that we went down hill skiing with Kanutte and Thor Helge. For people who like to see me make a fool of myself, here are some movies.

Most of the time I've been working at my thesis though, which is going pretty good. Two days ago I got ill, and I've been home so far. I'm feeling much better now, and think I'll be working at my thesis again tomorrow. Until 18:00 that is, because then Annett arrives in Groningen by train...

Online Address Book: Plaxo

2006-01-25T22:46:00.000+01:00

Since I'm moving to Oslo in a couple of months, I thought it was time to get my address book straightened out. After searching on the internet for some time I found Plaxo, which is actually a calender and an interactive todo list at the same time.

There are several versions of Plaxo. One is meant for Outlook (Express), one for Internet Explorer, one for Thunderbird and an online version. I choose to make use of the online version because of the same reason I'm using an online email web application (gmail), an online feed reader (T3h Blox0r), an online weblog web application (Blogger) etc.: accessibility.

The privacy and security seems to be fair, as you can read on this page. They seem to make money from the possibility to upgrade to Plaxo Premium, which has some nice but not necessary extra features.

An essential feature is that you can import all email addresses from Outlook, Yahoo!, Netscape, Mac OS X Address Book and from Gmail (and more). Of all the 350 people I ever had an email correspondence with using my Gmail account, there was exactly one person also using Plaxo. This is partly the reason I'm writing something about it on my blog, because if more people I know start using it, I don't have to fill in their information myself. :)

Any comments? What are you guys using?

Normal life in Oslo

2005-11-14T16:47:00.000+01:00

Sunday I came back from Oslo, where I spent two weeks living together with Annett. It was very nice! Because Annett can't just take two weeks off from her job, and I need to finish my thesis, we worked (most of the time)' during office hours. I started working on my take home examination on representation theory and reading a book about algebraic geometry.

In the weekend we went to Larvik to visit Annett's parents (Magne and Ann Iren), her younger brother (Gaute) and his girlfriend (Tina), her grandmother (`bestemor') and of course their dog (Bastian). They were all very kind to me and made me feel pretty comfortable.

On saturday Annett and I went to the cabin of her parents, where we stayed for one night. Here Annett worked on her upcoming presentation (about eels :)) and I continued working on my take home. The next morning the weather was so beautiful that we decided to borrow the canoe and spent three hours on the water. After this, we went to her parents house to eat dinner and returned home.

It were two great weeks and it was so nice to lead a normal, daily life together. I can't wait until Annett comes to Groningen to celebrate Sinterklaas with me...

Together in Groningen

2005-10-19T22:18:00.000+02:00

It's been a while since I wrote something on my blog, and this is primary because I've been spending pretty much all my time on working on my thesis. Not all my time ofcourse; the rest of my time goes to Skyping with Annett. :)

A week ago Annett came to Groningen to see me in my natural environment, and to see my friends and family. We had such a nice time! It was so nice to go out biking together, to go to the movies, to the jazz bar and to the disco.

I gave a party, in celebration of my birthday - that had taken place four months earlier - though it was ofcourse an everybody-meet-Annett-party. I got a lot of nice presents: thanks everybody! The best present I got was a beautiful book with Norwegian folk tales. Once I'm good enough in reading Bokmål, I can read a story everytime before I go to bed. :)

Back from Oslo

2005-09-13T20:06:00.000+02:00

Yesterday evening I came back from Oslo, where I visited Annett. It was so nice! First we visited Universitetet i Oslo and the city center. On Wednesday we left for a couple of days of hiking in the mountains in the neighbourhood of BolkesjÃ¸. The first day started very misty, but when this cleared up after a couple of hours a beautiful piece of Norway revealed itself. The second day there was a lot of rain, so we stayed in our tent most of the day and went out for a walk in the afternoon. At night it became extremely cold (couldn't feel my toes anymore), and since the wind had turned straight at the side of our tent and had become very strong we were almost sure the tent would blow away (especially since we had been too lazy to set it up in a decent way :) ).

When we came back in Oslo on Friday, we went to visit a student bar (which used to be called something like `integreerbar') to drink some Norwegian beers and see the student life. This was very cosy, and I think I drank a couple of beers too much there, especially since the day after we went to an amusement park: rollercoasters! I think I'll never get too old for those... In the evening we had a party had Annetts place. Thanks to a beamer borrowed from the university, we were able to project pictures from ICPS on the wall and made it into a nice afterparty.

Such a great week... In a few weeks Annett will come to The Netherlands, and I can show her some typically Dutch things. Any suggestions (besides liquorice)?

KIWI & Together in Oslo

2005-09-06T14:28:00.000+02:00

Friday I came back from KIWI 2005, a couple of days of beer, karaoke and silly games to get to know the new students from Mathematics and Computing Science. It was a lot of fun. Once the photos are available I'll post one here, and when the video of the karaoke is on the internet I'll post a link to it...

But there's better news: right now I'm at the University of Oslo together with Annett, the cute Norwegian girl I met in Coimbra a few weeks ago. So why am I sitting behind a computer? Annett had to go to a course on Greens Functions. :) Tomorrow we're going to walk for a couple of days in the mountains, about a two-hour drive away from here. I'll try to put out some pictures later!

Cleaning up the dirty file formats

2005-08-20T19:05:00.000+02:00

A couple of days ago I was discussing with a friend the problems of closed file formats like MP3. Now the awareness of these problems is increasing and most of the free alternatives exist, it is time to actively encourage the use of free file formats like PNG, OGG and OGM.

So how can we do this? Most of us get their content through file sharing programs. In return we distribute these files again to other people. If there was an easy tool with which one could select directories and free all the content in these directories, then we could participate in cleaning up the file sharing network of dirty file formats and spend practically no time at this. Maybe this program should be scheduled to run on a daily basis? By the nature of closed formats such a program would ofcourse be non-free (or maybe even illegal) itself, but I guess that can't be helped. Maybe it is a good idea to write a plugin for programs like Amule, Kazaa etc. to automatically convert dirty file formats into free formats?

And while we're at it, maybe file sharing clients can play a more active role in restoring meta data of the downloaded files. This will become especially important when desktops abandon the hierarchical tree structure for a searchable web of context (something that is done on a large scale already by multimedia applications).

Comments anyone?

Why wireless will end `piracy' and doom DRM and TCPA

2005-08-20T13:15:00.000+02:00

I read an interesting article about why wireless will end `piracy' and doom DRM and TCPA. If you're interested in the future of content, it is worth reading.

ICPS 2005

2005-08-20T13:03:00.000+02:00

Friday morning I came back from the International Conference for Physics Students, which took place in Coimbra. This was even more entertaining than Wikimania! In my case this meant eight days of meeting interesting people, hot weather, too little sleep, a lot of Portuguese beer, and long nights of partying. Oh wait, ofcourse I saw also some interesting physics. :) But most important of all, I met a very special girl...

The following picture gives an indication of our daily activities:

(Photo taken by Maarten Inklaar, released under the Creative Commons Attribution-ShareAlike License.)

Wikimania 2005

2005-08-08T21:51:00.000+02:00

Today I returned from Wikimania 2005 in Frankfurt am Main. What a great congres! This has absolutely been the most entertaining and interesting conference I ever attended. If you're interested, you can find some photos at Flickr, for example the following photo at the Wikimania party of Wikipedians on the dance floor:

Website for great ideas

2005-07-30T12:57:00.000+02:00

I came across a nice website. When you have a great idea, but not the possibility to work it out in detail or to apply it, you can post it at shouldexist.org. On the other hand, it is also a lot of fun to read some of these ideas.

My thoughts are the following: I think there are a lot of people with great ideas, and therefore many great ideas. What we really need are more hard-working people with persistence to work these ideas out in detail and apply them. These are the people that deserve more respect. A good idea alone is nothing.

Biking through Germany and Poland

2005-07-23T16:32:00.000+02:00

Just half an hour ago, Joost Smit and me returned from a biking-tour through Germany and Poland. It was a lot of fun! We met some nice and interesting people, for example Łukasz Król, who planned to bike in one month all the way through Poland, Germany, The Netherlands, United Kingdom and Iceland. He also took two pictures of us and uploaded it to his blog. Further more we found some beautiful spots to bike along and to camp and got very tanned. Bike-holidays are the best!

Hitchhiking Contest

2005-07-14T11:36:00.000+02:00

Sunday I returned to The Netherlands from the South of France. Together with Monique, I participated in a hitchhiking contest organized by the FMF. In two and a half days, our team was the last (5 / 5) to arrive at the destination, but we had a great time nevertheless. We also went back hitchhiking and this took us only one and half days (though we also used the train a little bit). It's rather easy if you know how to do it!

Anyway, we wrote our hitchhiking experiences down (in Dutch) and if you're curious you can take a look. When the photos are ready, I'll add them to the website.

Tomorrow I'm going to bike in Poland together with Joost Smit. I'm looking forward to that!

New Periodiek online

2005-06-22T00:43:00.000+02:00

The May-June edition of the Periodiek is now online. Check it out at the website of the Perio.

Log on my Trip to Beijing and Kuala Lumpur

2005-06-20T18:05:00.000+02:00

About a month ago I travelled to Beijing and Kuala Lumpur on a study tour organized by our student association the FMF. A few days ago I finished my personal log about the trip. If you're interested, check it out!

Overview of GNU/Linux distros

2005-06-19T23:11:00.000+02:00

I just read the following nice article that gives an overview of the main GNU/Linux distros.

Lectures in the open

2005-06-15T00:01:00.000+02:00

Today the weather was beautiful so we decided to do our seminar on game theory outside. We carried a whiteboard and tripod to the grass just outside the university building, and Jan Feitsma gave a talk on duopoly. It's great to attend a lecture in the open! Passants were also smiling a lot at us... :)

Teacher of the year!

2005-06-10T21:49:00.000+02:00

Today was a great day, because I won the 'Teacher of the Year (for exercise sessions)' award! Thanks a lot, all my students from Linear Algebra! I already knew for some time I was nominated, and today at the 'award show' I heard I won. All the nominees were supposed to give a five or ten minute talk. I didn't know what to say, so instead I sang a song together with Johan: 'Het Studentenassistentenlied'.

Birthday

2005-06-09T00:02:00.000+02:00

やった, it's my birthday! I'll start celebrating by sleeping a long long time. :)

Perioweekend

2005-06-08T16:39:00.000+02:00

I'm an editor for the Periodiek, the little magazine of our student association the FMF. This weekend we had 'Perioweekend', which means the weekend we put all the articles into the layout. Abel and I just finished the editorial proces. I'm not allowed to say too much about it yet, but I want to share the following picture with you:

Book: De Eeuw van mijn Vader

2005-06-04T00:01:00.000+02:00

The other day I finished reading 'De Eeuw van mijn Vader', written by Geert Mak. It's about the history of The Netherlands in the previous century. Just like the 'In Europa' it is written in a clever way and I learned a lot from it.

I recommend anyone who is interested in Dutch history to read this nice book.

EU Constitution

2005-06-02T00:40:00.000+02:00

I voted 'yes'. Why? I don't know.

New Feedreader

2005-05-29T12:39:00.000+02:00

Mark IJbema sent me a link to a new feedreader called t3h blox0r. Because it is a XUL application it only runs in Gecko browsers, like Mozilla and Firefox. But that's not a problem to me, because these are the only browsers I use anyway (and occasionally elinks).

Anyway, it has everything I want: the accessibility of a web application and the functionality of a good feedreader. Try it!

Programming Contest

2005-05-28T21:16:00.000+02:00

Today I participated in the IWI programmeerwedstrijd, the yearly programming contest of our university. My team, 'Het Halve Werk', consisted of Mark IJbema, Bart Dopheide, our team captain Jan Feitsma and me. Anyway, we came in second! I'm so proud! ;)

Movie NAM excursion

2005-05-21T14:19:00.000+02:00

A few months ago I went (on an excursion) to one of the Dutch islands. I just saw that the movie is ready. And yes, it is as cold as it seems...

Movie: excursion to Ameland - mpeg-2 version (larger)

Movie: excursion to Ameland - mpeg-4 version (smaller)

Some new articles

2005-05-14T17:48:00.000+02:00

Mark and I wrote some new articles (most of them in Dutch) as 'The Internet Explorers', about RSS, Wiki's, Wikipedia and an interview with Jimmy Wales. You can find it at the website of The Internet Explorers.

Also the next episode of the magazine of our student association (the FMF) is released, and I wrote some more articles in it (an interview with Nobelprize winner Frank Wilczek, an article about the unit History of Mathematics at the University of Groningen, an energy drink test). See it at the website of the Periodiek.

Cars give rise to the feeling of unsafety?

2005-01-22T15:43:00.000+01:00

Today I received a link to an essay (in dutch) that argues that the increasing number of cars is one of the causes for (the feeling of) unsafety on the streets (apart from the possibility of being hit by a car). The article is interesting and its main idea was new to me.

Free Culture

2004-12-04T23:08:00.000+01:00

I'm an associate member of the Free Software Foundation, which means I give them some money to support their principles.

The other day I received a present from them: the book `Free Culture' by Lawrence Lessig. The subtitle is `How big media uses technology and the law to lock down culture and control creativity.' One could take this as a summary of the book. It explains how creativity of the individual is supressed by US copyright law and new technologies.

The book is extremely well written. Its clear structure makes it easy to follow its argument. With lots of well worked out examples it illustrates its message. I recommend this book to anyone who is interested in copyright issues and freedom of creativity.

See its website.

Article about blog

2004-11-25T23:31:00.000+01:00

Just after finding out about blog, I decided (in my never ending arrogance) to write an article about it. Together with Mark IJbema I started writing this article (in Dutch) to spread the word. It will appear in de Periodiek, the little magazine of our student association.

It would be nice to receive some feedback.

I started my own blog

2004-11-21T13:38:00.000+01:00

Enough said.