The results of the 2021 MaxSAT Evaluation were just announced at the 2021 SAT conference (by me :)). My solver Loandra performed very well, taking first place in the weighted 300s track and fourth in all other tracks. The source code of that version of Loandra is already available at the evaluation website and in its repository.
I would like to thank my co-organizers of the Evaluation and the organizers of the SAT conference. I am looking forward to taking a closer look at the results.
A week ago I gave the second talk at the Simons Institute, this time at the Theoretical Foundations of SAT/SMT Solving seminar. The event webpage can be found here. I had the opportunity to talk about my work on preprocessing for Maximum Satisfiability, covering work done both during and after the preprocessing.
I would again like to thank Marjin Heule for considering me as a speaker for the event. Next time you can hear me speak is at Jakob Nordströms video seminars on the 4.6. I will talk about Abstract Cores in the IHS algorithm for MaxSAT, covering my recent paper from SAT 2020. Looking forward to seeing you there!
This spring I have been very fortunate to have been invited to give to talks at the various different seminars run by the Simons Institute in California.
The first talk on solving MaxSAT was given on the 13th of April together with Matti Järvisalo. The talk was a part of the Beyond Satisfiability seminar, a recording of it can be found here.
The second talk will be on MaxSAT preprocessing on May 5th as a part of the Theoretical Foundation of SAT/SMT solving workshop. More information can be found here. As the talk is online. I invite anyone who is interested to attend. I am sure the talks will be interesting, personally I am looking forward to hearing about SAT and QBF preprocessing form Benjamin and Martina.
I would like to thank the organisers of the various seminars of the Simons Institute for considering me as a speaker in their events.
I am happy to let you know that my Thesis: Solving Optimization Problems via Maximum Satisfiability: Encodings and Re-Encodings was awarded the international ACP Doctoral Thesis Award by the Association of Constraint Programming. I will be receiving the award and giving a presentation on my thesis on the 11.9 at the CP 2020 conference. The conference is virtual and free to attend, I hope to see you all there.
Im an honoured for receiving the price and want to thank the ACP for the recognition. My presentation can be found at: at google drive.
I am happy to let you know that my paper titled Abstract Cores in Implicit Hitting set MaxSat solving has been awarded a best paper award at the 2020 SAT conference. The paper reports on work that was started during my visit to Toronto in 2019. We propose a technique that seeks to address the inherent drawback in the so called implicit hitting set approach to MaxSAT solving, one of the most successful approaches to solving MaxSAT instances corresponding to real world applications. Abstract cores seek to reduce the number of cores that the algorithm needs to extract before terminating without increasing the complexity of the core extraction steps too much. The instantiation of this idea in the MaxHS solver was one of the best performing approaches in the 2020 MaxSAT Evaluation.
I would like to thank the conference organizers for the recognition and for putting together an event that, considering the current circumstances, was probably the best possible way of organizing SAT 2020. I would also like to thank my co-authors, especially Prof. Fahiem Bacchus for his efforts in the implementation and getting the experimental results.
The new decade has started well for me with two accepted publications already.
The first one, Preprocessing in Incomplete MaxSAT Solving is joint work with Marcus Leivo and Matti järvisalo, and is also Marcus first publication! The paper investigates the effect that preprocessing has on the non-optimal solutions of MAxSAT instances. The paper ties my recent work on incomplete MaxSAT solving with my earlier work on MaxSAT preprocessing and I am very excited to push this line of research further. It will be published in the proceedings of the 2020 ECAI conference. I will most likely be travelling there myself to present this work, we are also looking into proposing a tutorial for the conference.
The second paper, Core-Guided and Core-Boosted Search for CP, extends and generalises my work on incomplete MaxSAT solving to the more general finite domain constraint programming paradigm. The paper is joint work with Graeme Grange, Emir Demirovic and Peter Stuckey from Australia. I am surprised and pleased to see that our previous work on MaxSAT seems to work so well in CP solving as well. The paper will be published in the proceedings of the 2020 CPAIOR conference. I will most likely not travel there myself, but I am sure that my co-authors will do the paper justice.
I’d like to thank all my co-authors for their work, it’s been a pleasure collaborating and hopefully we can continue doing so. The papers will be added to this webpage when the publishing process is done. If you want to read them earlier, feel free to send me an e-mail.
The MaxSAT Evaluation is an annual event meant to evaluate the state of the art in MaxSAT solving technology. The evaluation has two tracks: the complete track, where the goal is to find the provably optimal solution as fast as possible and the incomplete track where the goal is to find a solution which is as good as possible within a limited time.
This year we submitted a solver called Loandra to the incomplete track of the competition. Loandra implements core boosted linear search, an idea described in this paper that I worked on during my visit to Melbourne last fall. The results of the Evaluations were presented yesterday at the SAT conference, I’ve only seen a summary but I am happy to say that Loandra performed very well, achieving the highest score on the unweighted 300s track and the second to highest on the weighted 300s track. Overall a very nice result, I am very pleased.
I’d like to thank the organizers of the MaxSAT evaluation as well as my co-authors, Emir Demirovic and Peter Stuckey! I am currently on a holiday, but once I get back I will put up Loandra on github as well. It will also eventually be made available here.
My PhD thesis: Solving Optimization Problems via Maximum Satisfiability : Encodings and Re-Encodings (available from e-thesis) was awarded one of four doctoral dissertation awards for 2018 of The University of Helsinki. I am grateful and honoured by this recognition. Thank you to everyone who played a role in my nomination and congratulations to my three other fellow recipients.