My Constraint Programming Blog

Tuesday, September 17

This is the first "real" day of the Conference. Yesterday, the workshop and doctoral program day, was the zeroth day.

Let me first say I'm sorry that I mislead you yesterday. The talks by Jun He and Pascal are not until tomorrow, Wednesday. That blog post is changed now. Also, it should probably be called "Day 0" but changing that would destroy the links.

And as of this morning, I'm the official offical conference blogger (yesterday I was only the inofficial official conference blogger). As you've already seen it's not about everything at the conference, just a report of what I happen to like or have noticed - as always on my blogs.

Here are some highlights from today.

These following two talks by Peter Stuckey I've really looked forward to:

First Peter's Invited talk "Those who forget the past are condemned to repeat it." The final words was "The Search is Dead. Long Live Proof". A very interesting and provocative talk; and the research is very interesting too, of course. It will very interesting to following this. As a modeler it would be nice with this as ground for a black box solver (at least in my dreams).

And then his report about MiniZinc challenge 2013 results. Here's the medals:

Medal	Fixed	Free	Par	Open
GOLD	opturion	opturion	or-tools	or-tools
SILVER	or-tools	or-tool	choco	choco
BRONZE	gecode	iz_plus	opturion	opturion

Congratulations to all!!

This year Opturion CPX and or-tools did really well. As Peter said: The king [Gecode] is dead, Long Live the King. Gecode finally knocked of its perch of winning ALL previous gold medals.

As in later years, the chuffed solver was actually the best solver in both fixed and free category but since it's a G12 solver it can't get any official place. However, or-tools was better than chuffed in the parallel class (and open) this year (with chuffed as second).

If you wonder how the FlatZinc solver by Neng-Fa Zhou and me (the Picat solver) did, it came last in all categories, which was not especially surprising for me; I'm glad we got some points. We'll try to do better the next year (and this is - as Peter mentioned - one of the purposes of the challenge).

Here is the URL from Peter's talk to the result page: http://www.minizinc.org/challenge2013/results2013.html [later: this link works now.]

Related: MiniZinc Challenge Medals 2008-2012

Peter also mentioned the competition at this conference : Lightning Model and Solve competition. The registration form is at the boards. After just some hours there where already about 10 registered. That's great!

Before lunch there was also the three Best Papers talks. All was perhaps not in my forte but really worthwhile listening to.

After the lunch, I went strictly to the left column in the program: first the Applications track, and then the Bin Packing track. One of my two favorite talks where Helmut Simonis' talk about an application of Model Seeker (the last year I blogged about it in Beldiceanu and Simonis: A Model Seeker). The other talk was Andrea Rendl's about Balancing Bike Balancing System. I like these kind of practical applications (and which are not very hard to understand.)

It was interesting to learn that CP was used to calculate orbits in chaotic systems; a long time ago I read some popular science books - as well as some not-so-popular books - about this, and played with quite a few chaos systems

(I didn't attend the ACP General Assembly.)

The scheduled day ended with a reception drink at Östgöta nation. I hope everyone else had lovely discussions and made new contacts.

Assorted things

I was asked about notes from the panel discussion at CP Solver workshop yesterday. Unfortunately we didn't take any notes, but I hope to collect the highlights later this week.

Today's people greet (i.e. the one I've only e-communicated with before and today at least shaked hands with): Narendra Jussien, Barry O'Sullivan, Andrea Rendl, Peter Nightingale. There are still some left to greet. I also made some new friends, and this is actually one of the reason I'm attending this conference. It was mostly CP solver guys and should be to no surprise to the followers of this blog.

Finally, for you you who don't know me earlier: I'm the guy that sometimes wearing an eye patch. Please don't worry, it's just because I don't have a lens in my left eye after an unsuccessful cataract operation this May, and sometimes too much light tend to confuse my small brain. Eventually this will be fixed with a special contact lens.