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Introducing UniCorT: an iterative university course timetabling tool with MaxSAT

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Abstract

This paper describes the UniCorT tool designed to solve university course timetabling problems specifically tailored for the 2019 International Timetabling Competition (ITC 2019). The proposed approach includes pre-processing, the use of a maximum satisfiability (MaxSAT) solver and a local search procedure. UniCorT is assessed with the benchmark instances from the ITC 2019. The impact of a handful of techniques in the quality of the solution and the execution time is evaluated. We take into account different pre-processing techniques and conjunctive normal form (CNF) encodings, as well as the combination with a local search procedure. The success of our tool is attested by having been ranked among the five finalists of the ITC 2019 competition.

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Notes

  1. https://www.itc2019.org/home

  2. One of these encodings has already been successfully applied to solve the minimal perturbation problem in a university course timetabling setting (Lemos et al. 2020c).

  3. The code is available at https://github.com/itc2019/edon-gashi.

  4. The code is available at https://github.com/itc2019/tomas-muller.

  5. https://www.itc2019.org/validator, accessed in August 2020.

  6. RAPIDXML is available at http://rapidxml.sourceforge.net/, accessed in February 2019.

  7. TT-Open-WBO-Inc won both the Weighted Incomplete tracks at MaxSAT Evaluation 2019. The results are available at https://maxsat-evaluations.github.io/2019/.

  8. We converted all the weights for the same measurement unit. For this reason, we computed the worst possible cost for each instance and used this value to compute a value between 0 and 1.

  9. UniCorT in its best configuration.

  10. Obtained from https://www.itc2019.org/, accessed in August 2020.

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Correspondence to Alexandre Lemos.

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This is a substantially extended and revised version of (Lemos et al. 2020b).

The authors would like to thank the reviewers for their helpful comments and suggestions that contributed to an improved manuscript. This work was supported by national funds through Fundação para a Ciência e a Tecnologia (FCT) with references SFRH/BD/143212/2019 (PhD grant), DSAIPA/AI/0033/2019 (project LAIfeBlood), DSAIPA/AI/0044/2018 (project Data2help) and UIDB/50021/2020 (INESC-ID multi-annual funding)

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Lemos, A., Monteiro, P.T. & Lynce, I. Introducing UniCorT: an iterative university course timetabling tool with MaxSAT. J Sched 25, 371–390 (2022). https://doi.org/10.1007/s10951-021-00695-6

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