IMO Amsterdam – Day 5 (20 July 2011)

Today is the excursion day! A tiring one, though.

We had to get up early and go to the first excursion. We’re going to Den Haag.

First, was the long bus trip. Although it wasn’t as long as from Bremen to Wangerooge, it is still long, approximately 60 kilometres.

Then we got off to Den Haag, and Paul led us in Den Haag. To my surprise, we left most of the teams there, so we’re on our own. I was really worried we’re going to got lost, forgetting that we had Paul!

It was a short, nice stroll, deviating the main route, to see beautiful bridges and buildings. We even see another Indonesian restaurant there. Then we got back to meet some of the teams, which is waiting outside the Escher museum to open.

Escher in het Paleis is a museum dedicated to M.C. Escher, which uses a building which was a former Winter Palace of Queen Mother Emma of the Netherlands. This unique combination surprised me. The museum was small, and makes my mind confused, because Escher’s art is somewhat goes with the concept of infinity and impossibility. Take a look at this:

or this:

To be frank, I’m a little bit dizzy there. But his arts are beautiful, and considering they were made from carved wood, or maybe pencil sketch (I forgot what phrase they do to describe it), it’s just crazy, considering, for example, the latter picture, which is very, very intricate.

There was also a photo booth to take the picture. But, the result will be distorted from the original photo; the left side will be looked bigger, and the right side will be looked smaller. We tried this, and I’ve been trying to find the photograph. I’ll scan it and upload it here as soon as possible. It is really funny.

Then we got out, and we took a walk in Den Haag. Seeing the Parliament building, and then going to Madurodam, Netherlands’ smallest city. It was a miniature city, and it was really complex. They are scaled 1:25 to the real buildings. There are, for example, Utrecht train station, Amsterdam Airport Schiphol, the Vredespaleis in Den Haag, and many other buildings, from old to new. Even Unilever building is there.

I was even more impressed by the fact that the buildings are made to cope up with Dutch’s unpredictable weather; sometimes sunny and sometimes rainy. Those buildings could stand for 30 years, and they are maintaining it. There was, even, small miniature people to made the city more lively. And when I was visiting Madurodam, there was people maintaining some of the buildings, and placed the small people to the ground. Now I wish I could photograph that.

Then we went to the beach. It was really windy and cold. And there was people swimming and even wore bikinis. Maybe this is the new definition of Dress to Kill. I don’t even dare to move my hand out of my pocket for a few first minutes. Not for long though.

We choose to build something, made from sand, on the beach, along with almost all of Indonesian team. And that turned out to be, somewhat, good.

And Paul’s sleeping on the sand. We took a picture of him secretly, and I will upload it, along with the rest of all my pictures in my camera.

Then we took a bus ride back to Novotel. Really tiring. And what greet us at Novotel, is my score:

P1 P2 P3 P4 P5 P6
* – 1 – 0 – 7 – * – *

Where * is the undetermined score, yet. Tomorrow the scores for problem 1, 5, and 6 will be revealed. Fingers crossed.

I was really tired, because of the excursion. And I had to go (along with almost the rest of Indonesian team) to a lecture titled

Optimizing trips, trains, and tracks

In optimizing trips, there were 1 problem posed: How to find the shortest path from one place to another, which could be determined by Dijkstra’s algorithm, and the traveling salesman problem. Here, I quote the problem statement from Wikipedia

We denote by messenger problem (since in practice this question should be solved by each postman, anyway also by many travelers) the task to find, for finitely many points whose pairwise distances are known, the shortest route connecting the points. Of course, this problem is solvable by finitely many trials. Rules which would push the number of trials below the number of permutations of the given points, are not known. The rule that one first should go from the starting point to the closest point, then to the point closest to this, etc., in general does not yield the shortest route.

which is still a hard problem to do (no algorithm known yet).

The second topic was about the lecturer’s experience to create a train timetable for Dutch’s complex train system. With several rules and given travelling time between stations, and also the given transit time between 2 trains, all of these conditions given by the Dutch railway company must be satisfied with the timetable that would be constructed by mathematicians and programmers.

The third part was about Sam Loyd’s problem about trains. I’ll give you the video for you to enjoy

Well, that’s it from now. Sorry for delaying the updates, the excursions are just too many, I have little time to update my blog. I am still suffering jet flag from Amsterdam, and as such unable to write long posts, as my head is still somewhat dizzy.

I’m signing off from Jakarta, Indonesia.