CASTOR invited me to spend a month at KTH in September 2019, an offer I was more than happy to accept since it would give me the opportunity to reconnect with colleagues in Sweden, spend time in Stockholm (which I had visited frequently during my PhD studies), and present my work on the MiniZinc constraint modelling system.
As part of my visit, I gave a three-day course on Modelling and Solving Combinatorial Problems with MiniZinc, to an audience of around 20 PhD students, KTH staff and industry partners. In several workshop sessions we went through the basic concepts of declarative, constraint-based modelling, using lots of hands-on examples. Using the MiniZinc system (developed by me and my team at Monash University), the participants were able to experiment with different modelling techniques and state-of-the-art solving algorithms, including the Gecode constraint solver developed at KTH. I really enjoyed the interaction and discussions that arose from the workshops, and it was great to hear how many participants could see applications of constraint modelling in their own area of work.
On the research side of my visit, I spent most of the time developing and discussing new and improved algorithms and implementation techniques for MiniZinc and Gecode. This time-out from the usual stress of teaching, administration, grant writing etc. was very valuable, and I want to thank all the members of the CASTOR team I met for the diverse inputs and discussions. This laid the foundation and kick-started the development for the next major version of the MiniZinc system.
Finally, I want to say a few words about Christian Schulte, who invited me and organised my visit. He was my PhD supervisor, mentor, and most importantly, my friend. Sadly, he passed away in March 2020. I am extremely grateful to have had the opportunity to spend time with him last year, have discussions about all kinds of topics (some of them even related to work…), and share a few really nice meals. I will always feel a strong connection to KTH thanks to him, and hope that I’ll be able to visit again sometime in the future.
Guido Tack, Melbourne, June 2020