Header Image

Integer Optimization

mixed-integer (nonlinear) programming; nonconvex optimization; exact linear programming; cutting planes; branch-and-bound; SCIP Optimization Suite

Ksenia Bestuzheva

We develop theory and solution methodologies for linear and nonlinear mixed-integer optimization programs (MIPs). Our primary focus lies in enhancing the efficiency of integer and spatial branch-and-bound algorithms, which provide a general-purpose approach to finding provable global optima and coordinate within one framework components such as relaxations, cutting planes, primal heuristics, presolving procedures, and other solving techniques. Our group works on all these aspects and their interaction within the constraint integer programming solver SCIP. We also work on algorithms combining satisfiability and MIP techniques such as conflict analysis and domain propagation; on exact MIP and linear programming, guaranteeing that solutions are not invalidated by floating-point arithmetic errors; and on polynomial optimization problems.

Members

Ksenia Bestuzheva
bestuzheva (at) zib.de
Alexander Hoen
hoen (at) zib.de
Antonia Chmiela
chmiela (at) zib.de
Deborah Hendrych
hendrych (at) zib.de
Gabriele Iommazzo
iommazzo (at) zib.de
Gioni Mexi
mexi (at) zib.de
Hannah Troppens
troppens (at) zib.de
Julian Manns
manns (at) zib.de
Kilian Runnwerth
runnwerth (at) zib.de
Lara Glessen
glessen (at) zib.de
Leon Eifler
eifler (at) zib.de
Matea Miskovic
miskovic (at) zib.de
Mohammed Ghannam
ghannam (at) zib.de
Patricia Ebert
ebert (at) zib.de
Stefan Vigerske
vigerske (at) zib.de
Suresh Bolusani
bolusani (at) zib.de

Projects

Publications

  1. Bolusani, S., Besançon, M., Bestuzheva, K., Chmiela, A., Dionísio, J., Donkiewicz, T., van Doornmalen, J., Eifler, L., Ghannam, M., Gleixner, A., Graczyk, C., Halbig, K., Hedtke, I., Hoen, A., Hojny, C., van der Hulst, R., Kamp, D., Koch, T., Kofler, K., … Xu, L. (2024). The SCIP Optimization Suite 9.0 (ZIB Report No. 24-02-29). Zuse Institute Berlin. [URL] [arXiv] [code]
    [BibTeX]
    @techreport{BolusaniEtal2024,
  year = {2024},
  institution = {Zuse Institute Berlin},
  type = {ZIB Report},
  month = feb,
  number = {24-02-29},
  url = {https://nbn-resolving.org/urn:nbn:de:0297-zib-95528},
  archiveprefix = {arXiv},
  eprint = {2402.17702},
  primaryclass = {math.OC},
  author = {Bolusani, Suresh and Besançon, Mathieu and Bestuzheva, Ksenia and Chmiela, Antonia and Dionísio, João and Donkiewicz, Tim and van Doornmalen, Jasper and Eifler, Leon and Ghannam, Mohammed and Gleixner, Ambros and Graczyk, Christoph and Halbig, Katrin and Hedtke, Ivo and Hoen, Alexander and Hojny, Christopher and van der Hulst, Rolf and Kamp, Dominik and Koch, Thorsten and Kofler, Kevin and Lentz, Jurgen and Manns, Julian and Mexi, Gioni and Mühmer, Erik and Pfetsch, Marc and Schlösser, Franziska and Serrano, Felipe and Shinano, Yuji and Turner, Mark and Vigerske, Stefan and Weninger, Dieter and Xu, Liding},
  title = {The SCIP Optimization Suite 9.0},
  code = {https://scipopt.org}
}
  2. Borst, S., Eifler, L., and Gleixner, A. (2024). Certified Constraint Propagation and Dual Proof Analysis in a Numerically Exact MIP Solver. [arXiv]
    [BibTeX]
    @misc{BorstEiflerGleixner2024_CertifiedConstraintPropagation,
  archiveprefix = {arXiv},
  eprint = {2403.13567},
  primaryclass = {math.OC},
  year = {2024},
  author = {Borst, Sander and Eifler, Leon and Gleixner, Ambros},
  title = {Certified Constraint Propagation and Dual Proof Analysis in a Numerically Exact MIP Solver}
}
  3. Eifler, L., and Gleixner, A. (2024). Safe and Verified Gomory Mixed Integer Cuts in a Rational MIP Framework. SIAM Journal on Optimization, 34(1), 742–763. DOI: 10.1137/23M156046X [URL]
    [BibTeX]
    @article{EiflerGleixner2023_Safeandverified,
  year = {2024},
  journal = {SIAM Journal on Optimization},
  volume = {34},
  number = {1},
  pages = {742-763},
  doi = {10.1137/23M156046X},
  note = {ZIB report 23-09},
  url = {https://nbn-resolving.org/urn:nbn:de:0297-zib-90159},
  author = {Eifler, Leon and Gleixner, Ambros},
  title = {Safe and Verified Gomory Mixed Integer Cuts in a Rational MIP Framework}
}
  4. Eifler, L., Witzig, J., and Gleixner, A. (2024). Branch and Cut for Partitioning a Graph Into a Cycle of Clusters. Proceedings of International Symposium on Combinatorial Optimization. [arXiv]
    [BibTeX]
    @inproceedings{EiflerWitzigGleixner2024,
  year = {2024},
  booktitle = {Proceedings of International Symposium on Combinatorial Optimization},
  archiveprefix = {arXiv},
  eprint = {2401.08412},
  primaryclass = {math.OC},
  author = {Eifler, Leon and Witzig, Jakob and Gleixner, Ambros},
  title = {Branch and Cut for Partitioning a Graph Into a Cycle of Clusters}
}
  5. Ghannam, M., Mexi, G., Lam, E., and Gleixner, A. (2024). Branch and Price for the Length-constrained Cycle Partition Problem. Proceedings of INFORMS Optimization Society Conference. [URL] [arXiv]
    [BibTeX]
    @inproceedings{GhannamMexiLamGleixner2024,
  year = {2024},
  booktitle = {Proceedings of INFORMS Optimization Society Conference},
  url = {https://sites.google.com/view/ios2024refereed},
  archiveprefix = {arXiv},
  eprint = {2401.17937},
  primaryclass = {math.OC},
  author = {Ghannam, Mohammed and Mexi, Gioni and Lam, Edward and Gleixner, Ambros},
  title = {Branch and Price for the Length-constrained Cycle Partition Problem}
}
  6. Halbig, K., Hoen, A., Gleixner, A., Witzig, J., and Weninger, D. (2024). A Diving Heuristic for Mixed-integer Problems with Unbounded Semi-continuous Variables. [arXiv]
    [BibTeX]
    @misc{HalbigHoenGleixnerWitzigWeninger2024_Adivingheuristic,
  archiveprefix = {arXiv},
  eprint = {2403.19411},
  primaryclass = {math.OC},
  year = {2024},
  author = {Halbig, Katrin and Hoen, Alexander and Gleixner, Ambros and Witzig, Jakob and Weninger, Dieter},
  title = {A Diving Heuristic for Mixed-integer Problems with Unbounded Semi-continuous Variables}
}
  7. Hoen, A., Oertel, A., Gleixner, A., and Nordström, J. (2024). Certifying MIP-based Presolve Reductions for 0-1 Integer Linear Programs. Proceedings of International Conference on the Integration of Constraint Programming, Artificial Intelligence, and Operations Research. [arXiv]
    [BibTeX]
    @inproceedings{HoenOertelGleixnerNordstroem2024,
  year = {2024},
  booktitle = {Proceedings of International Conference on the Integration of Constraint Programming, Artificial Intelligence, and Operations Research},
  archiveprefix = {arXiv},
  eprint = {2401.09277},
  primaryclass = {math.OC},
  author = {Hoen, Alexander and Oertel, Andy and Gleixner, Ambros and Nordström, Jakob},
  title = {Certifying MIP-based Presolve Reductions for 0-1 Integer Linear Programs}
}
  8. Sharma, K., Hendrych, D., Besançon, M., and Pokutta, S. (2024). Network Design for the Traffic Assignment Problem with Mixed-Integer Frank-Wolfe. Proceedings of INFORMS Optimization Society Conference. [arXiv]
    [BibTeX]
    @inproceedings{SharmaNetworkDesignTrafficFrankWolfe24,
  year = {2024},
  booktitle = {Proceedings of INFORMS Optimization Society Conference},
  archiveprefix = {arXiv},
  eprint = {2402.00166},
  primaryclass = {math.OC},
  author = {Sharma, Kartikey and Hendrych, Deborah and Besançon, Mathieu and Pokutta, Sebastian},
  title = {Network Design for the Traffic Assignment Problem with Mixed-Integer Frank-Wolfe}
}
  9. Hendrych, D., Besançon, M., and Pokutta, S. (2024). Solving the Optimal Experiment Design Problem with Mixed-integer Convex Methods. Proceedings of Symposium on Experimental Algorithms. [arXiv]
    [BibTeX]
    @inproceedings{design_of_experiments_boscia_23,
  year = {2024},
  booktitle = {Proceedings of Symposium on Experimental Algorithms},
  archiveprefix = {arXiv},
  eprint = {2312.11200},
  primaryclass = {math.OC},
  author = {Hendrych, Deborah and Besançon, Mathieu and Pokutta, Sebastian},
  title = {Solving the Optimal Experiment Design Problem with Mixed-integer Convex Methods}
}
  10. Göß, A., Martin, A., Pokutta, S., and Sharma, K. (2024). Norm-induced Cuts: Optimization with Lipschitzian Black-box Functions. [URL] [arXiv]
    [BibTeX]
    @misc{gmps_nic_23,
  url = {https://opus4.kobv.de/opus4-trr154/files/518/nic_preprint.pdf},
  archiveprefix = {arXiv},
  eprint = {2403.11546},
  primaryclass = {math.OC},
  year = {2024},
  author = {Göß, Adrian and Martin, Alexander and Pokutta, Sebastian and Sharma, Kartikey},
  title = {Norm-induced Cuts: Optimization with Lipschitzian Black-box Functions}
}
  11. Mexi, G., Shamsi, S., Besançon, M., and le Bodic, P. (2024). Probabilistic Lookahead Strong Branching Via a Stochastic Abstract Branching Model. Proceedings of International Conference on the Integration of Constraint Programming, Artificial Intelligence, and Operations Research. [arXiv]
    [BibTeX]
    @inproceedings{probabilistic_lookahead_23,
  year = {2024},
  booktitle = {Proceedings of International Conference on the Integration of Constraint Programming, Artificial Intelligence, and Operations Research},
  archiveprefix = {arXiv},
  eprint = {2312.07041},
  primaryclass = {math.OC},
  author = {Mexi, Gioni and Shamsi, Somayeh and Besançon, Mathieu and le Bodic, Pierre},
  title = {Probabilistic Lookahead Strong Branching Via a Stochastic Abstract Branching Model}
}
  12. Tjusila, G., Besançon, M., Turner, M., and Koch, T. (2024). How Many Clues To Give? A Bilevel Formulation For The Minimum Sudoku Clue Problem. Operations Research Letters. DOI: 10.1016/j.orl.2024.107105 [URL] [arXiv]
    [BibTeX]
    @article{sudoku_clues_23,
  year = {2024},
  journal = {Operations Research Letters},
  doi = {10.1016/j.orl.2024.107105},
  url = {https://sciencedirect.com/science/article/abs/pii/S0167637724000415},
  archiveprefix = {arXiv},
  eprint = {2305.01697},
  primaryclass = {math.OC},
  author = {Tjusila, Gennesaret and Besançon, Mathieu and Turner, Mark and Koch, Thorsten},
  title = {How Many Clues To Give? A Bilevel Formulation For The Minimum Sudoku Clue Problem.}
}
  13. Berthold, T., Mexi, G., and Salvagnin, D. (2023). Using Multiple Reference Vectors and Objective Scaling in the Feasibility Pump. EURO Journal on Computational Optimization, 11. DOI: 10.1016/j.ejco.2023.100066
    [BibTeX]
    @article{BertholdMexiSalvagnin2023,
  year = {2023},
  journal = {EURO Journal on Computational Optimization},
  volume = {11},
  doi = {10.1016/j.ejco.2023.100066},
  author = {Berthold, Timo and Mexi, Gioni and Salvagnin, Domenico},
  title = {Using Multiple Reference Vectors and Objective Scaling in the Feasibility Pump}
}
  14. Bestuzheva, K., Besançon, M., Chen, W.-K., Chmiela, A., Donkiewicz, T., van Doornmalen, J., Eifler, L., Gaul, O., Gamrath, G., Gleixner, A., Gottwald, L., Graczyk, C., Halbig, K., Hoen, A., Hojny, C., van der Hulst, R., Koch, T., Lübbecke, M., Maher, S. J., … Witzig, J. (2023). Enabling Research Through the SCIP Optimization Suite 8.0. ACM Transactions on Mathematical Software. DOI: 10.1145/3585516 [arXiv]
    [BibTeX]
    @article{BestuzhevaBesanconEtal2023,
  year = {2023},
  journal = {ACM Transactions on Mathematical Software},
  doi = {10.1145/3585516},
  archiveprefix = {arXiv},
  eprint = {2303.07101},
  primaryclass = {math.OC},
  author = {Bestuzheva, Ksenia and Besançon, Mathieu and Chen, Wei-Kun and Chmiela, Antonia and Donkiewicz, Tim and van Doornmalen, Jasper and Eifler, Leon and Gaul, Oliver and Gamrath, Gerald and Gleixner, Ambros and Gottwald, Leona and Graczyk, Christoph and Halbig, Katrin and Hoen, Alexander and Hojny, Christopher and van der Hulst, Rolf and Koch, Thorsten and Lübbecke, Marco and Maher, Stephen J. and Matter, Frederic and Mühmer, Erik and Müller, Benjamin and Pfetsch, Marc and Rehfeldt, Daniel and Schlein, Steffan and Schlösser, Franziska and Serrano, Felipe and Shinano, Yuji and Sofranac, Boro and Turner, Mark and Vigerske, Stefan and Wegscheider, Fabian and Wellner, Philipp and Weninger, Dieter and Witzig, Jakob},
  title = {Enabling Research Through the SCIP Optimization Suite 8.0}
}
  15. Bestuzheva, K., Chmiela, A., Müller, B., Serrano, F., Vigerske, S., and Wegscheider, F. (2023). Global Optimization of Mixed-integer Nonlinear Programs with SCIP 8.0. Journal of Global Optimization. DOI: 10.1007/s10898-023-01345-1 [URL] [arXiv]
    [BibTeX]
    @article{BestuzhevaChmielaMueller2023_GlobalOptimizationOfMixedInteger,
  year = {2023},
  journal = {Journal of Global Optimization},
  doi = {10.1007/s10898-023-01345-1},
  note = {ZIB report 23-01},
  url = {https://nbn-resolving.org/urn:nbn:de:0297-zib-89348},
  archiveprefix = {arXiv},
  eprint = {2301.00587},
  primaryclass = {math.OC},
  author = {Bestuzheva, Ksenia and Chmiela, Antonia and Müller, Benjamin and Serrano, Felipe and Vigerske, Stefan and Wegscheider, Fabian},
  title = {Global Optimization of Mixed-integer Nonlinear Programs with SCIP 8.0}
}
  16. Bestuzheva, K., Gleixner, A., and Achterberg, T. (2023). Efficient Separation of RLT Cuts for Implicit and Explicit Bilinear Products. Proceedings of Conference on Integer Programming and Combinatorial Optimization, 14–28. DOI: 10.1007/978-3-031-32726-1_2 [arXiv]
    [BibTeX]
    @inproceedings{BestuzhevaGleixnerAchterberg2023_EfficientSeparationOfRLT,
  year = {2023},
  booktitle = {Proceedings of Conference on Integer Programming and Combinatorial Optimization},
  pages = {14-28},
  doi = {10.1007/978-3-031-32726-1_2},
  archiveprefix = {arXiv},
  eprint = {2211.13545},
  primaryclass = {math.OC},
  author = {Bestuzheva, Ksenia and Gleixner, Ambros and Achterberg, Tobias},
  title = {Efficient Separation of RLT Cuts for Implicit and Explicit Bilinear Products}
}
  17. Bestuzheva, K., Gleixner, A., and Vigerske, S. (2023). A Computational Study of Perspective Cuts. Mathematical Programming Computation, 15, 703–731. DOI: 10.1007/s12532-023-00246-4 [URL] [arXiv]
    [BibTeX]
    @article{BestuzhevaGleixnerVigerske2023,
  year = {2023},
  journal = {Mathematical Programming Computation},
  volume = {15},
  pages = {703-731},
  doi = {10.1007/s12532-023-00246-4},
  note = {ZIB report 21-07},
  url = {https://nbn-resolving.org/urn:nbn:de:0297-zib-81821},
  archiveprefix = {arXiv},
  eprint = {2103.09573},
  primaryclass = {math.OC},
  author = {Bestuzheva, Ksenia and Gleixner, Ambros and Vigerske, Stefan},
  title = {A Computational Study of Perspective Cuts}
}
  18. Bolusani, S., Besançon, M., Gleixner, A., Berthold, T., D’Ambrosio, C., Muñoz, G., Paat, J., and Thomopulos, D. (2023). The MIP Workshop 2023 Computational Competition on Reoptimization. [arXiv]
    [BibTeX]
    @misc{BolusaniEtal2023_TheMIP,
  archiveprefix = {arXiv},
  eprint = {2311.14834},
  primaryclass = {math.OC},
  year = {2023},
  author = {Bolusani, Suresh and Besançon, Mathieu and Gleixner, Ambros and Berthold, Timo and D'Ambrosio, Claudia and Muñoz, Gonzalo and Paat, Joseph and Thomopulos, Dimitri},
  title = {The MIP Workshop 2023 Computational Competition on Reoptimization}
}
  19. Chmiela, A., Gleixner, A., Lichocki, P., and Pokutta, S. (2023). Online Learning for Scheduling MIP Heuristics. Proceedings of International Conference on the Integration of Constraint Programming, Artificial Intelligence, and Operations Research, 114–123. DOI: 10.1007/978-3-031-33271-5_8
    [BibTeX]
    @inproceedings{ChmielaGleixnerLichockiPokutta2023_OnlineLearning,
  year = {2023},
  booktitle = {Proceedings of International Conference on the Integration of Constraint Programming, Artificial Intelligence, and Operations Research},
  pages = {114-123},
  doi = {10.1007/978-3-031-33271-5_8},
  author = {Chmiela, Antonia and Gleixner, Ambros and Lichocki, Pawel and Pokutta, Sebastian},
  title = {Online Learning for Scheduling MIP Heuristics}
}
  20. Chmiela, A., Muñoz, G., and Serrano, F. (2023). Monoidal Strengthening and Unique Lifting in MIQCPs. Proceedings of Conference on Integer Programming and Combinatorial Optimization. [URL]
    [BibTeX]
    @inproceedings{ChmielaMunozSerrano2023_Monoidal,
  year = {2023},
  booktitle = {Proceedings of Conference on Integer Programming and Combinatorial Optimization},
  url = {https://gonzalomunoz.org/monoidalforMIQCP.pdf},
  author = {Chmiela, Antonia and Muñoz, Gonzalo and Serrano, Felipe},
  title = {Monoidal Strengthening and Unique Lifting in MIQCPs}
}
  21. Eifler, L., and Gleixner, A. (2023). A Computational Status Update for Exact Rational Mixed Integer Programming. Mathematical Programming, 197, 793–812. DOI: 10.1007/s10107-021-01749-5
    [BibTeX]
    @article{EiflerGleixner2023_Acomputational,
  year = {2023},
  journal = {Mathematical Programming},
  volume = {197},
  pages = {793-812},
  doi = {10.1007/s10107-021-01749-5},
  author = {Eifler, Leon and Gleixner, Ambros},
  title = {A Computational Status Update for Exact Rational Mixed Integer Programming}
}
  22. Ghannam, M., and Gleixner, A. (2023). Hybrid Genetic Search for Dynamic Vehicle Routing with Time Windows. Proceedings of Conference of the Society for Operations Research in Germany. [arXiv]
    [BibTeX]
    @inproceedings{HGSforDVRPTW,
  year = {2023},
  booktitle = {Proceedings of Conference of the Society for Operations Research in Germany},
  archiveprefix = {arXiv},
  eprint = {2307.11800},
  primaryclass = {cs.NE},
  author = {Ghannam, Mohammed and Gleixner, Ambros},
  title = {Hybrid Genetic Search for Dynamic Vehicle Routing with Time Windows}
}
  23. Gleixner, A., Gottwald, L., and Hoen, A. (2023). PaPILO: a Parallel Presolving Library for Integer and Linear Programming with Multiprecision Support. INFORMS Journal on Computing. DOI: 10.1287/ijoc.2022.0171 [arXiv]
    [BibTeX]
    @article{HoenGottwaldGleixner2023_PaPILO,
  year = {2023},
  journal = {INFORMS Journal on Computing},
  doi = {10.1287/ijoc.2022.0171},
  archiveprefix = {arXiv},
  eprint = {2206.10709},
  primaryclass = {math.OC},
  author = {Gleixner, Ambros and Gottwald, Leona and Hoen, Alexander},
  title = {PaPILO: a Parallel Presolving Library for Integer and Linear Programming with Multiprecision Support}
}
  24. Liberti, L., Iommazzo, G., Lavor, C., and Maculan, N. (2023). Cycle-based Formulations in Distance Geometry. Open Journal of Mathematical Optimization, 4(1). DOI: 10.5802/ojmo.18 [arXiv]
    [BibTeX]
    @article{LIL+23,
  year = {2023},
  journal = {Open Journal of Mathematical Optimization},
  volume = {4},
  number = {1},
  doi = {10.5802/ojmo.18},
  archiveprefix = {arXiv},
  eprint = {2006.11523},
  primaryclass = {math.OC},
  author = {Liberti, Leo and Iommazzo, Gabriele and Lavor, Carlile and Maculan, Nelson},
  title = {Cycle-based Formulations in Distance Geometry}
}
  25. Turner, M., Chmiela, A., Koch, T., and Winkler, M. (2023). PySCIPOpt-ML: Embedding Trained Machine Learning Models Into Mixed-integer Programs. [arXiv]
    [BibTeX]
    @misc{TurnerChmielaKochWinkler2023_EmbeddingMLinMIPs,
  archiveprefix = {arXiv},
  eprint = {2312.08074},
  primaryclass = {math.OC},
  year = {2023},
  author = {Turner, Mark and Chmiela, Antonia and Koch, Thorsten and Winkler, Michael},
  title = {PySCIPOpt-ML: Embedding Trained Machine Learning Models Into Mixed-integer Programs}
}
  26. Eifler, L., Nicolas-Thouvenin, J., and Gleixner, A. (2023). Combining Precision Boosting with LP Iterative Refinement for Exact Linear Optimization. [arXiv]
    [BibTeX]
    @misc{arXiv:2311.08037,
  archiveprefix = {arXiv},
  eprint = {2311.08037},
  primaryclass = {math.OC},
  year = {2023},
  author = {Eifler, Leon and Nicolas-Thouvenin, Jules and Gleixner, Ambros},
  title = {Combining Precision Boosting with LP Iterative Refinement for Exact Linear Optimization}
}
  27. Turner, M., Berthold, T., and Besançon, M. (2023). A Context-Aware Cutting Plane Selection Algorithm for Mixed-Integer Programming. Proceedings of Conference of the Society for Operations Research in Germany. [arXiv]
    [BibTeX]
    @inproceedings{context_cutsel_23,
  year = {2023},
  booktitle = {Proceedings of Conference of the Society for Operations Research in Germany},
  archiveprefix = {arXiv},
  eprint = {2307.07322},
  primaryclass = {math.OC},
  author = {Turner, Mark and Berthold, Timo and Besançon, Mathieu},
  title = {A Context-Aware Cutting Plane Selection Algorithm for Mixed-Integer Programming}
}
  28. Turner, M., Berthold, T., Besançon, M., and Koch, T. (2023). Cutting Plane Selection with Analytic Centers and Multiregression. Proceedings of International Conference on the Integration of Constraint Programming, Artificial Intelligence, and Operations Research.
    [BibTeX]
    @inproceedings{cutsel_acenter_22,
  year = {2023},
  booktitle = {Proceedings of International Conference on the Integration of Constraint Programming, Artificial Intelligence, and Operations Research},
  author = {Turner, Mark and Berthold, Timo and Besançon, Mathieu and Koch, Thorsten},
  title = {Cutting Plane Selection with Analytic Centers and Multiregression}
}
  29. Mexi, G., Berthold, T., Gleixner, A., and Nordström, J. (2023). Improving Conflict Analysis in MIP Solvers by Pseudo-Boolean Reasoning. Proceedings of 29th International Conference on Principles and Practice of Constraint Programming (CP 2023), 280, 27:1–27:19, DOI: 10.4230/LIPIcs.CP.2023.27
    [BibTeX]
    @inproceedings{mexi2023improving,
  year = {2023},
  booktitle = {Proceedings of 29th International Conference on Principles and Practice of Constraint Programming (CP 2023)},
  volume = {280},
  pages = {27:1-27:19,},
  doi = {10.4230/LIPIcs.CP.2023.27},
  author = {Mexi, Gioni and Berthold, Timo and Gleixner, Ambros and Nordström, Jakob},
  title = {Improving Conflict Analysis in MIP Solvers by Pseudo-Boolean Reasoning}
}
  30. Mexi, G., Besançon, M., Bolusani, S., Chmiela, A., Hoen, A., and Gleixner, A. (2023). Scylla: a Matrix-free Fix-propagate-and-project Heuristic for Mixed-integer Optimization. Proceedings of Conference of the Society for Operations Research in Germany. [arXiv]
    [BibTeX]
    @inproceedings{scyllaheuristic,
  year = {2023},
  booktitle = {Proceedings of Conference of the Society for Operations Research in Germany},
  archiveprefix = {arXiv},
  eprint = {2307.03466},
  primaryclass = {math.OC},
  author = {Mexi, Gioni and Besançon, Mathieu and Bolusani, Suresh and Chmiela, Antonia and Hoen, Alexander and Gleixner, Ambros},
  title = {Scylla: a Matrix-free Fix-propagate-and-project Heuristic for Mixed-integer Optimization}
}
  31. van Doornmalen, J., Eifler, L., Gleixner, A., and Hojny, C. (2023). A Proof System for Certifying Symmetry and Optimality Reasoning in Integer Programming. [arXiv]
    [BibTeX]
    @misc{vanDoornmalenEiflerGleixnerHojny2023,
  archiveprefix = {arXiv},
  eprint = {2311.03877},
  primaryclass = {math.OC},
  year = {2023},
  author = {van Doornmalen, Jasper and Eifler, Leon and Gleixner, Ambros and Hojny, Christopher},
  title = {A Proof System for Certifying Symmetry and Optimality Reasoning in Integer Programming}
}
  32. Gasse, M., Bowly, S., Cappart, Q., Charfreitag, J., Charlin, L., Chételat, D., Chmiela, A., Dumouchelle, J., Gleixner, A., Kazachkov, A. M., Khalil, E., Lichocki, P., Lodi, A., Lubin, M., Maddison, C. J., Christopher, M., Papageorgiou, D. J., Parjadis, A., Pokutta, S., … Kun, M. (2022). The Machine Learning for Combinatorial Optimization Competition (ML4CO): Results and Insights. Proceedings of Conference on Neural Information Processing Systems, 176, 220–231. [URL] [arXiv]
    [BibTeX]
    @inproceedings{GasseEtal2022_ML4CO,
  year = {2022},
  booktitle = {Proceedings of Conference on Neural Information Processing Systems},
  month = jun,
  volume = {176},
  pages = {220–231},
  url = {https://proceedings.mlr.press/v176/gasse22a.html},
  archiveprefix = {arXiv},
  eprint = {2203.02433},
  primaryclass = {cs.LG},
  author = {Gasse, Maxime and Bowly, Simon and Cappart, Quentin and Charfreitag, Jonas and Charlin, Laurent and Chételat, Didier and Chmiela, Antonia and Dumouchelle, Justin and Gleixner, Ambros and Kazachkov, Aleksandr M. and Khalil, Elias and Lichocki, Pawel and Lodi, Andrea and Lubin, Miles and Maddison, Chris J. and Christopher, Morris and Papageorgiou, Dimitri J. and Parjadis, Augustin and Pokutta, Sebastian and Prouvost, Antoine and Scavuzzo, Lara and Zarpellon, Giulia and Yang, Linxin and Lai, Sha and Wang, Akang and Luo, Xiaodong and Zhou, Xiang and Huang, Haohan and Shao, Shengcheng and Zhu, Yuanming and Zhang, Dong and Quan, Tao and Cao, Zixuan and Xu, Yang and Huang, Zhewei and Zhou, Shuchang and Binbin, Chen and Minggui, He and Hao, Hao and Zhiyu, Zhang and Zhiwu, An and Kun, Mao},
  title = {The Machine Learning for Combinatorial Optimization Competition (ML4CO): Results and Insights}
}
  33. Bestuzheva, K., Gleixner, A., and Völker, H. (2022). Strengthening SONC Relaxations with Constraints Derived From Variable Bounds. Proceedings of Proceedings of the Hungarian Global Optimization Workshop HUGO 2022, 41–44. [URL] [arXiv]
    [BibTeX]
    @inproceedings{BestuzhevaGleixnerVoelker2022_StrengtheningSONC,
  year = {2022},
  booktitle = {Proceedings of Proceedings of the Hungarian Global Optimization Workshop HUGO 2022},
  pages = {41-44},
  url = {https://inf.u-szeged.hu/hugo/},
  archiveprefix = {arXiv},
  eprint = {2304.12145},
  primaryclass = {math.OC},
  author = {Bestuzheva, Ksenia and Gleixner, Ambros and Völker, Helena},
  title = {Strengthening SONC Relaxations with Constraints Derived From Variable Bounds}
}
  34. Bolusani, S., and Ralphs, T. K. (2022). A Framework for Generalized Benders’ Decomposition and Its Applications to Multilevel Optimization. Mathematical Programming, 196, 389–426. DOI: 10.1007/s10107-021-01763-7 [arXiv]
    [BibTeX]
    @article{BolRal22,
  year = {2022},
  journal = {Mathematical Programming},
  volume = {196},
  pages = {389-426},
  doi = {10.1007/s10107-021-01763-7},
  archiveprefix = {arXiv},
  eprint = {2104.06496},
  primaryclass = {math.OC},
  author = {Bolusani, Suresh and Ralphs, Ted K.},
  title = {A Framework for Generalized Benders' Decomposition and Its Applications to Multilevel Optimization}
}
  35. Chmiela, A., Muñoz, G., and Serrano, F. (2022). On the Implementation and Strengthening of Intersection Cuts for QCQPs. Mathematical Programming B, 197, 549–586. DOI: 10.1007/s10107-022-01808-5
    [BibTeX]
    @article{ChmielaMunozSerrano2021_Onimplementation,
  year = {2022},
  journal = {Mathematical Programming B},
  volume = {197},
  pages = {549-586},
  doi = {10.1007/s10107-022-01808-5},
  author = {Chmiela, Antonia and Muñoz, Gonzalo and Serrano, Felipe},
  title = {On the Implementation and Strengthening of Intersection Cuts for QCQPs}
}
  36. Eifler, L., Gleixner, A., and Pulaj, J. (2022). A Safe Computational Framework for Integer Programming Applied to Chvátal’s Conjecture. ACM Transactions on Mathematical Software, 48(2), 1–12. DOI: 10.1145/3485630
    [BibTeX]
    @article{EiflerGleixnerPulaj2022_Asafecomputational,
  year = {2022},
  journal = {ACM Transactions on Mathematical Software},
  volume = {48},
  number = {2},
  pages = {1-12},
  doi = {10.1145/3485630},
  author = {Eifler, Leon and Gleixner, Ambros and Pulaj, Jonad},
  title = {A Safe Computational Framework for Integer Programming Applied to Chvátal's Conjecture}
}
  37. Hoppmann-Baum, K., Burdakov, O., Mexi, G., Casselgren, C. J., and Koch, T. (2022). Length-Constrained Cycle Partition with an Application to UAV Routing. Optimization Methods and Software. DOI: 10.1080/10556788.2022.2053972
    [BibTeX]
    @article{HoppmannBaumBurdakovMexietal.2022,
  year = {2022},
  journal = {Optimization Methods and Software},
  doi = {10.1080/10556788.2022.2053972},
  author = {Hoppmann-Baum, Kai and Burdakov, Oleg and Mexi, Gioni and Casselgren, Carl Johan and Koch, Thorsten},
  title = {Length-Constrained Cycle Partition with an Application to UAV Routing}
}
  38. Iommazzo, G., D’Ambrosio, C., Frangioni, A., and Liberti, L. (2022). Algorithm Configuration Problem. In Encyclopedia of Optimization (pp. 1–8). DOI: 10.1007/978-3-030-54621-2_749-1
    [BibTeX]
    @incollection{IDF+22,
  year = {2022},
  booktitle = {Encyclopedia of Optimization},
  pages = {1-8},
  doi = {10.1007/978-3-030-54621-2_749-1},
  author = {Iommazzo, Gabriele and D'Ambrosio, Claudia and Frangioni, Antonio and Liberti, Leo},
  title = {Algorithm Configuration Problem}
}
  39. Sofranac, B., Gleixner, A., and Pokutta, S. (2022). Accelerating Domain Propagation: An Efficient GPU-parallel Algorithm Over Sparse Matrices. Parallel Computing, 109, 102874. DOI: 10.1016/j.parco.2021.102874 [arXiv] [summary]
    [BibTeX]
    @article{SofranacGleixnerPokutta2022_Accelerating,
  year = {2022},
  journal = {Parallel Computing},
  volume = {109},
  pages = {102874},
  doi = {10.1016/j.parco.2021.102874},
  archiveprefix = {arXiv},
  eprint = {2009.07785},
  primaryclass = {cs.DC},
  author = {Sofranac, Boro and Gleixner, Ambros and Pokutta, Sebastian},
  title = {Accelerating Domain Propagation: An Efficient GPU-parallel Algorithm Over Sparse Matrices},
  summary = {https://pokutta.com/blog/research/2020/09/20/gpu-prob.html}
}
  40. Sofranac, B., Gleixner, A., and Pokutta, S. (2022). An Algorithm-independent Measure of Progress for Linear Constraint Propagation. Constraints, 27, 432–455. DOI: 10.1007/s10601-022-09338-9 [arXiv]
    [BibTeX]
    @article{SofranacGleixnerPokutta2022_AnAlgorithm-IndependentMeasure,
  year = {2022},
  journal = {Constraints},
  volume = {27},
  pages = {432-455},
  doi = {10.1007/s10601-022-09338-9},
  archiveprefix = {arXiv},
  eprint = {2106.07573},
  primaryclass = {math.OC},
  author = {Sofranac, Boro and Gleixner, Ambros and Pokutta, Sebastian},
  title = {An Algorithm-independent Measure of Progress for Linear Constraint Propagation}
}
  41. Hendrych, D., Troppens, H., Besançon, M., and Pokutta, S. (2022). Convex Integer Optimization with Frank-Wolfe Methods. [arXiv] [slides] [code]
    [BibTeX]
    @misc{htbp_cio_22,
  archiveprefix = {arXiv},
  eprint = {2208.11010},
  primaryclass = {math.OC},
  year = {2022},
  author = {Hendrych, Deborah and Troppens, Hannah and Besançon, Mathieu and Pokutta, Sebastian},
  title = {Convex Integer Optimization with Frank-Wolfe Methods},
  code = {https://github.com/ZIB-IOL/Boscia.jl},
  slides = {https://pokutta.com/slides/20220915_boscia.pdf}
}
  42. Kossen, T., Hirzel, M. A., Madai, V. I., Boenisch, F., Hennemuth, A., Hildebrand, K., Pokutta, S., Sharma, K., Hilbert, A., Sobesky, J., Galinovic, I., Khalil, A. A., Fiebach, J. B., and Frey, D. (2022). Towards Sharing Brain Images: Differentially Private TOF-MRA Images with Segmentation Labels Using Generative Adversarial Networks. Frontiers in Artificial Intelligence. DOI: 10.3389/frai.2022.813842
    [BibTeX]
    @article{khmbhhpshsgkff_22,
  year = {2022},
  journal = {Frontiers in Artificial Intelligence},
  doi = {10.3389/frai.2022.813842},
  author = {Kossen, Tabea and Hirzel, Manuel A. and Madai, Vince I. and Boenisch, Franziska and Hennemuth, Anja and Hildebrand, Kristian and Pokutta, Sebastian and Sharma, Kartikey and Hilbert, Adam and Sobesky, Jan and Galinovic, Ivana and Khalil, Ahmed A. and Fiebach, Jochen B. and Frey, Dietmar},
  title = {Towards Sharing Brain Images: Differentially Private TOF-MRA Images with Segmentation Labels Using Generative Adversarial Networks}
}
  43. Bestuzheva, K., Besançon, M., Chen, W.-K., Chmiela, A., Donkiewicz, T., van Doornmalen, J., Eifler, L., Gaul, O., Gamrath, G., Gleixner, A., Gottwald, L., Graczyk, C., Halbig, K., Hoen, A., Hojny, C., van der Hulst, R., Koch, T., Lübbecke, M., Maher, S. J., … Witzig, J. (2021). The SCIP Optimization Suite 8.0 (ZIB Report No. 21-41). Zuse Institute Berlin. [URL] [code]
    [BibTeX]
    @techreport{BestuzhevaBesanconEtal2021,
  year = {2021},
  institution = {Zuse Institute Berlin},
  type = {ZIB Report},
  month = dec,
  number = {21-41},
  url = {https://nbn-resolving.org/urn:nbn:de:0297-zib-85309},
  author = {Bestuzheva, Ksenia and Besançon, Mathieu and Chen, Wei-Kun and Chmiela, Antonia and Donkiewicz, Tim and van Doornmalen, Jasper and Eifler, Leon and Gaul, Oliver and Gamrath, Gerald and Gleixner, Ambros and Gottwald, Leona and Graczyk, Christoph and Halbig, Katrin and Hoen, Alexander and Hojny, Christopher and van der Hulst, Rolf and Koch, Thorsten and Lübbecke, Marco and Maher, Stephen J. and Matter, Frederic and Mühmer, Erik and Müller, Benjamin and Pfetsch, Marc and Rehfeldt, Daniel and Schlein, Steffan and Schlösser, Franziska and Serrano, Felipe and Shinano, Yuji and Sofranac, Boro and Turner, Mark and Vigerske, Stefan and Wegscheider, Fabian and Wellner, Philipp and Weninger, Dieter and Witzig, Jakob},
  title = {The SCIP Optimization Suite 8.0},
  code = {https://scipopt.org}
}
  44. Chmiela, A., Khalil, E. B., Gleixner, A., Lodi, A., and Pokutta, S. (2021). Learning to Schedule Heuristics in Branch-and-bound. Proceedings of Conference on Neural Information Processing Systems, 34, 24235–24246. [URL] [arXiv] [poster]
    [BibTeX]
    @inproceedings{CKGLP2021,
  year = {2021},
  booktitle = {Proceedings of Conference on Neural Information Processing Systems},
  month = mar,
  volume = {34},
  pages = {24235–24246},
  url = {https://proceedings.neurips.cc/paper_files/paper/2021/file/cb7c403aa312160380010ee3dd4bfc53-Paper.pdf},
  archiveprefix = {arXiv},
  eprint = {2103.10294},
  primaryclass = {cs.LG},
  author = {Chmiela, Antonia and Khalil, Elias B. and Gleixner, Ambros and Lodi, Andrea and Pokutta, Sebastian},
  title = {Learning to Schedule Heuristics in Branch-and-bound},
  poster = {https://pokutta.com/slides/20211120_poster_NeurIPS21_learningheuristics.pdf}
}
  45. Bolusani, S., Coniglio, S., Ralphs, T. K., and Tahernejad, S. (2021). A Unified Framework for Multistage Mixed Integer Linear Optimization. [arXiv]
    [BibTeX]
    @misc{BolConRalTah20,
  archiveprefix = {arXiv},
  eprint = {2104.09003},
  primaryclass = {math.OC},
  year = {2021},
  author = {Bolusani, Suresh and Coniglio, Stefano and Ralphs, Ted K. and Tahernejad, Sahar},
  title = {A Unified Framework for Multistage Mixed Integer Linear Optimization}
}
  46. Ramin, E., Bestuzheva, K., Gargalo, C., Ramin, D., Schneider, C., Ramin, P., Flores-Alsina, X., Andersen, M., and Gernaey, K. (2021). Incremental Design of Water Symbiosis Networks with Prior Knowledge: the Case of an Industrial Park in Kenya. Science of the Total Environment, 751. DOI: 10.1016/j.scitotenv.2020.141706
    [BibTeX]
    @article{RaminBestuzhevaGargalo2021_IncrementalDesignOfWater,
  year = {2021},
  journal = {Science of the Total Environment},
  volume = {751},
  doi = {10.1016/j.scitotenv.2020.141706},
  author = {Ramin, Elham and Bestuzheva, Ksenia and Gargalo, Carina and Ramin, Danial and Schneider, Carina and Ramin, Pedram and Flores-Alsina, Xavier and Andersen, Maj and Gernaey, Krist},
  title = {Incremental Design of Water Symbiosis Networks with Prior Knowledge: the Case of an Industrial Park in Kenya}
}
  47. Hoppmann-Baum, K., Mexi, G., Burdakov, O., Casselgren, C. J., and Koch, T. (2020). Minimum Cycle Partition with Length Requirements. Proceedings of International Conference on the Integration of Constraint Programming, Artificial Intelligence, and Operations Research, 12296, 273–282. DOI: 10.1007/978-3-030-58942-4_18
    [BibTeX]
    @inproceedings{HoppmannBaumMexiBurdakovetal.2020,
  year = {2020},
  booktitle = {Proceedings of International Conference on the Integration of Constraint Programming, Artificial Intelligence, and Operations Research},
  volume = {12296},
  pages = {273-282},
  doi = {10.1007/978-3-030-58942-4_18},
  author = {Hoppmann-Baum, Kai and Mexi, Gioni and Burdakov, Oleg and Casselgren, Carl Johan and Koch, Thorsten},
  title = {Minimum Cycle Partition with Length Requirements}
}
  48. Turner, M., Berthold, T., Besançon, M., and Koch, T. Branching Via Cutting Plane Selection: Improving Hybrid Branching. [arXiv]
    [BibTeX]
    @misc{branching_cutsel_23,
  archiveprefix = {arXiv},
  eprint = {2306.06050},
  primaryclass = {math.OC},
  author = {Turner, Mark and Berthold, Timo and Besançon, Mathieu and Koch, Thorsten},
  title = {Branching Via Cutting Plane Selection: Improving Hybrid Branching}
}