TY - CHAP A1 - Gasse, Maxime A1 - Bowly, Simon A1 - Cappart, Quentin A1 - Charfreitag, Jonas A1 - Charlin, Laurent A1 - Chételat, Didier A1 - Chmiela, Antonia A1 - Dumouchelle, Justin A1 - Gleixner, Ambros A1 - Kazachkov, Aleksandr M. A1 - Khalil, Elias A1 - Lichocki, Pawel A1 - Lodi, Andrea A1 - Lubin, Miles A1 - Maddison, Chris J. A1 - Christopher, Morris A1 - Papageorgiou, Dimitri J. A1 - Parjadis, Augustin A1 - Pokutta, Sebastian A1 - Prouvost, Antoine A1 - Scavuzzo, Lara A1 - Zarpellon, Giulia A1 - Yang, Linxin A1 - Lai, Sha A1 - Wang, Akang A1 - Luo, Xiaodong A1 - Zhou, Xiang A1 - Huang, Haohan A1 - Shao, Shengcheng A1 - Zhu, Yuanming A1 - Zhang, Dong A1 - Quan, Tao A1 - Cao, Zixuan A1 - Xu, Yang A1 - Huang, Zhewei A1 - Zhou, Shuchang A1 - Binbin, Chen A1 - Minggui, He A1 - Hao, Hao A1 - Zhiyu, Zhang A1 - Zhiwu, An A1 - Kun, Mao T1 - The Machine Learning for Combinatorial Optimization Competition (ML4CO): results and insights T2 - Proceedings of Conference on Neural Information Processing Systems Y1 - 2022 ER - TY - CHAP A1 - Ebert, Patricia A1 - Masing, Berenike A1 - Lindner, Niels A1 - Gleixner, Ambros T1 - Sorting Criteria for Line-based Periodic Timetabling Heuristics T2 - Operations Research Proceedings 2024. OR 2024 N2 - It is well-known that optimal solutions are notoriously hard to find for the Periodic Event Scheduling Problem (PESP), which is the standard mathematical formulation to optimize periodic timetables in public transport. We consider a class of incremental heuristics that have been demonstrated to be effective by Lindner and Liebchen (2023), however, for only one fixed sorting strategy of lines along which a solution is constructed. Thus, in this paper, we examine a variety of sortings based on the number, weight, weighted span, and lower bound of arcs, and test for each setting various combinations of the driving, dwelling, and transfer arcs of lines. Additionally, we assess the impact on the incremental extension of the event-activity network by minimizing resp. maximizing a connectivity measure between subsets of lines. We compare our 27 sortings on the railway instances of the benchmarking library PESPlib within the ConcurrentPESP solver framework. We are able to find five new incumbent solutions, resulting in improvements of up to 2%. Y1 - 2025 SP - 348 EP - 354 ER - TY - JOUR A1 - Halbig, Katrin A1 - Hoen, Alexander A1 - Gleixner, Ambros A1 - Witzig, Jakob A1 - Weninger, Dieter T1 - A diving heuristic for mixed-integer problems with unbounded semi-continuous variables JF - EURO Journal on Computational Optimization Y1 - 2025 U6 - https://doi.org/10.1016/j.ejco.2025.100107 VL - 13 ER - TY - JOUR A1 - Bestuzheva, Ksenia A1 - Gleixner, Ambros A1 - Achterberg, Tobias T1 - Efficient separation of RLT cuts for implicit and explicit bilinear terms JF - Mathematical Programming Y1 - 2025 U6 - https://doi.org/10.1007/s10107-024-02104-0 VL - 210 SP - 47 EP - 74 ER - TY - JOUR A1 - Hoen, Alexander A1 - Kamp, Dominik A1 - Gleixner, Ambros T1 - MIP-DD: Delta Debugging for Mixed-Integer Programming Solvers JF - INFORMS Journal on Computing Y1 - 2025 U6 - https://doi.org/10.1287/ijoc.2024.0844 ER - TY - CHAP A1 - Mexi, Gioni A1 - Besançon, Mathieu A1 - Bolusani, Suresh A1 - Chmiela, Antonia A1 - Hoen, Alexander A1 - Gleixner, Ambros T1 - Scylla: a matrix-free fix-propagate-and-project heuristic for mixed-integer optimization T2 - Proceedings of Conference of the Society for Operations Research in Germany Y1 - 2023 ER -