Stefano GualandiUniversity of Pavia

Research

Computational methods for AI and hard (NP-hard) problems, based on mathematical optimization, machine learning and constraint programming.

The most complete and up-to-date list of my publications, with citation metrics, is on Google Scholar and ORCID. The list below is a curated selection; green labels (arXiv, PDF, open access, preprint) point to freely available versions. My research group’s projects are on compopt.it.

Recent preprints

  • A. Sacilotto, A. M. Bernardelli, S. Gualandi. Comparative analysis of linear battery models for carbon emission optimization in solar energy systems arXiv:2606.26648, 2026. arXiv
  • G. Riccardi, A. M. Bernardelli, S. Gualandi. Theoretical perspectives on Jabr-type convex relaxations for AC optimal power flow arXiv:2604.00664, 2026. arXiv

Journal articles

  1. V. Ranjan, J. Park, S. Gualandi, A. Lodi, B. Stellato. Exact verification of first-order methods via mixed-integer linear programming SIAM Journal on Optimization, accepted for publication, 2026. arXiv
  2. A. Sosso, A. M. Bernardelli, S. Gualandi. The cloven traveling salesman: cycle covers and the integrality gap of small ATSP instances Optimization Letters, pp. 1–36, 2026. doiarXiv
  3. G. Maggiorano, S. Gualandi, P. Avella, M. Mele. Enhancing the separation of rank-1 Chvátal–Gomory cuts from knapsack sets Operations Research Letters, 67, 107451, 2026. doi
  4. G. Riccardi, B. Urso, S. Gualandi. A constraint disaggregation method for structure-preserving aggregations in LP problems: application to renewable energy grids with hydrogen storage Optimization and Engineering, 27(3), pp. 2193–2237, 2026. doipreprint
  5. G. Auricchio, M. Ghiotto, S. Gualandi, G. Toscani. Generalized Galton’s boards explain social phenomena via statistical physics Scientific Reports, 16(1), 93, 2025. doiopen access
  6. E. Vercesi, J. Barta, L. M. Gambardella, S. Gualandi, M. Mastrolilli. On the integrality gap of small asymmetric traveling salesman problems: a polyhedral and computational approach Discrete Optimization, 57, 100901, 2025. doiarXiv
  7. A. M. Bernardelli, S. Gualandi, S. Milanesi, H. C. Lau, N. Yorke-Smith. Multiobjective linear ensembles for robust and sparse training of few-bit neural networks INFORMS Journal on Computing, 37(3), pp. 623–643, 2025. doiarXiv
  8. L. Bonasera, S. Gualandi. Optimal shapelets tree for time series interpretable classification EURO Journal on Computational Optimization, 12, 100091, 2024. doiopen access
  9. F. Ricciato, S. Gualandi. The Kantorovich–Wasserstein distance for spatial statistics: the Spatial-KWD library Statistical Journal of the IAOS, 40(1), pp. 109–123, 2024. doiopen access
  10. G. Auricchio, L. Ferrarini, S. Gualandi, G. Lanzarotto, L. Pernazza. Computing aperiodic tiling rhythmic canons via SAT models Constraints, 29(3–4), pp. 215–233, 2024. doi
  11. E. Vercesi, S. Gualandi, M. Mastrolilli, L. M. Gambardella. On the generation of metric TSP instances with a large integrality gap by branch-and-cut Mathematical Programming Computation, 15(2), pp. 389–416, 2023. doiarXiv
  12. G. Auricchio, A. Codegoni, S. Gualandi, L. Zambon. The Fourier discrepancy function Communications in Mathematical Sciences, 21(3), pp. 627–639, 2023. doiarXiv
  13. S. Gualandi, G. Toscani, E. Vercesi. A kinetic description of the body size distributions of species Mathematical Models and Methods in Applied Sciences, 32(14), pp. 2853–2885, 2022. doi
  14. L. Ferrarini, S. Gualandi. Total coloring and total matching: polyhedra and facets European Journal of Operational Research, 303(1), pp. 129–142, 2022. doiarXiv
  15. S. Coniglio, S. Gualandi. Optimizing over the closure of rank inequalities with a small right-hand side for the maximum stable set problem via bilevel programming INFORMS Journal on Computing, 34(2), pp. 1006–1023, 2022. doi
  16. F. Bassetti, S. Gualandi, M. Veneroni. On the computation of Kantorovich–Wasserstein distances between two-dimensional histograms by uncapacitated minimum cost flows SIAM Journal on Optimization, 30(3), pp. 2441–2469, 2020. doiarXiv
  17. G. Auricchio, A. Codegoni, S. Gualandi, G. Toscani, M. Veneroni. The equivalence of Fourier-based and Wasserstein metrics on imaging problems Rendiconti Lincei, Matematica e Applicazioni, 31(3), pp. 627–649, 2020. doiarXiv
  18. S. Gualandi, G. Toscani. Size distribution of cities: A kinetic explanation Physica A: Statistical Mechanics and its Applications, 524, pp. 221–234, 2019. doiarXiv
  19. S. Gualandi, G. Toscani. Human behavior and lognormal distribution. A kinetic description Mathematical Models and Methods in Applied Sciences, 29(4), pp. 717–753, 2019. doiarXiv
  20. M. Chiarandini, R. Fagerberg, S. Gualandi. Handling preferences in student-project allocation Annals of Operations Research, 275(1), pp. 39–78, 2019. doiPDF
  21. S. Gualandi, G. Toscani. Pareto tails in socio-economic phenomena: a kinetic description Economics: The Open-Access, Open-Assessment E-Journal, 12(1), 2018-31, 2018. doiopen access
  22. S. Gualandi, G. Toscani. Call center service times are lognormal: A Fokker–Planck description Mathematical Models and Methods in Applied Sciences, 28(8), pp. 1513–1527, 2018. doiarXiv
  23. B. Rostami, F. Malucelli, P. Belotti, S. Gualandi. Lower bounding procedure for the asymmetric quadratic traveling salesman problem European Journal of Operational Research, 253(3), pp. 584–592, 2016. doiPDF
  24. M. Lombardi, S. Gualandi. A Lagrangian propagator for artificial neural networks in constraint programming Constraints, 21(4), pp. 435–462, 2016. doi
  25. S. Carosi, S. Gualandi, F. Malucelli, E. Tresoldi. Delay management in public transportation: service regularity issues and crew re-scheduling Transportation Research Procedia, 10, pp. 483–492, 2015. doiopen access
  26. G. Galbiati, S. Gualandi, F. Maffioli. On minimum reload cost cycle cover Discrete Applied Mathematics, 164(1), pp. 112–120, 2014. doiopen access
  27. E. Amaldi, S. Coniglio, S. Gualandi. Coordinated cutting plane generation via multi-objective separation Mathematical Programming, 143(1), pp. 87–110, 2014. doipreprint
  28. S. Gualandi, F. Maffioli, C. Magni. Branch-and-price approach to the k-clustering minimum biclique completion problem International Transactions in Operational Research, 20(1), pp. 101–117, 2013. doi
  29. S. Gualandi, F. Malucelli. Constraint programming-based column generation Annals of Operations Research, 204(1), pp. 11–32, 2013. doi
  30. M. Chiarandini, L. Di Gaspero, S. Gualandi, A. Schaerf. The balanced academic curriculum problem revisited Journal of Heuristics, 18(1), pp. 119–148, 2012. doi
  31. S. Gualandi, F. Malucelli. A simple branching scheme for vertex coloring problems Discrete Applied Mathematics, 160(1–2), pp. 192–196, 2012. doiopen access
  32. S. Gualandi, F. Malucelli. Exact solution of graph coloring problems via constraint programming and column generation INFORMS Journal on Computing, 24(1), pp. 81–100, 2012. doi
  33. A. Capone, S. Gualandi, D. Yuan. Joint routing and scheduling optimization in arbitrary ad hoc networks: comparison of cooperative and hop-by-hop forwarding Ad Hoc Networks, 9(7), pp. 1256–1269, 2011. doiPDF
  34. A. Capone, L. Chen, S. Gualandi, D. Yuan. A new computational approach for maximum link activation in wireless networks under the SINR model IEEE Transactions on Wireless Communications, 10(5), pp. 1368–1372, 2011. doiPDF
  35. F. Amigoni, S. Gualandi, D. Menotti, G. Sangiovanni. A multiagent architecture for controlling the Palamede satellite Web Intelligence and Agent Systems, 8(3), pp. 269–289, 2010. doi
  36. A. Capone, G. Carello, I. Filippini, S. Gualandi, F. Malucelli. Routing, scheduling and channel assignment in wireless mesh networks: optimization models and algorithms Ad Hoc Networks, 8(6), pp. 545–563, 2010. doi
  37. A. Capone, G. Carello, I. Filippini, S. Gualandi, F. Malucelli. Solving a resource allocation problem in wireless mesh networks: a comparison between a CP-based and a classical column generation Networks, 55(3), pp. 221–233, 2010. doi
  38. G. Galbiati, S. Gualandi, F. Maffioli. Computational experience with a SDP-based algorithm for maximum cut with limited unbalance Networks, 55(3), pp. 247–255, 2010. doi
  39. S. Gualandi. Enhancing CP-based column generation for integer programs 4OR – A Quarterly Journal of Operations Research, 7(3), pp. 289–292, 2009. doi
  40. S. Gualandi, F. Malucelli. Constraint programming-based column generation: a survey (invited survey) 4OR – A Quarterly Journal of Operations Research, 7(2), pp. 113–137, 2009. doi

Peer-reviewed conference proceedings

  1. G. Auricchio, M. Ghiotto, S. Gualandi. A grid efficient transport optimization model for the Wasserstein barycenter problem Advances in Neural Information Processing Systems (NeurIPS 2026), to appear, 2026. NeurIPS
  2. N. Blin, S. Gualandi, C. M. Maes, A. Lodi, B. Stellato. Batched first-order methods for parallel LP solving in MIP Proc. 43rd International Conference on Machine Learning (ICML 2026), 2026. Honorable mention, Harvey J. Greenberg Research Award. arXiv
  3. L. Ferrarini, S. Gualandi, L. Moro, A. Parmentier. Learning primal heuristics for 0–1 knapsack interdiction problems Proc. CPAIOR 2025, LNCS, pp. 222–238, 2025. doi
  4. L. Bonasera, D. Duma, S. Gualandi. Learning sparse-lets for interpretable classification of event-interval sequences Proc. Metaheuristics International Conference (MIC 2024), LNCS, pp. 3–18, 2024. doi
  5. A. M. Bernardelli, S. Gualandi, H. C. Lau, S. Milanesi. The BeMi stardust: a structured ensemble of binarized neural networks Proc. Learning and Intelligent Optimization (LION 17), LNCS, pp. 443–458, 2023. doi
  6. S. Gualandi, F. Ricciato, C. Tomasi. Wasserstein distances for spatial statistics: the Spatial-KWD library Proc. New Techniques and Technologies for Statistics (NTTS 2023), European Commission, Brussels, 2023.
  7. A. Codegoni, S. Gualandi, F. Ricciato. On the application of the Fourier-based distance to spatial statistics Proc. New Techniques and Technologies for Statistics (NTTS 2023), European Commission, Brussels, 2023.
  8. E. Vercesi, S. Gualandi, M. Mastrolilli, L. M. Gambardella. Predicting the empirical hardness of metric TSP instances Operations Research and Data Science in Public Services (AIROYoung 2023), AIRO Springer Series, pp. 1–16, 2023. doi
  9. G. Auricchio, L. Ferrarini, S. Gualandi, G. Lanzarotto, L. Pernazza. A SAT encoding to compute aperiodic tiling rhythmic canons Proc. CPAIOR 2022, LNCS, pp. 14–23, 2022. doiarXiv
  10. P.-Y. Bouchet, S. Gualandi, L.-M. Rousseau. Primal heuristics for Wasserstein barycenters Proc. CPAIOR 2020, LNCS, pp. 239–255, 2020. Distinguished Paper Award. doi
  11. G. Auricchio, F. Bassetti, S. Gualandi, M. Veneroni. Computing Wasserstein barycenters via linear programming Proc. CPAIOR 2019, LNCS, pp. 355–363, 2019. doi
  12. G. Auricchio, S. Gualandi, M. Veneroni. The maximum nearby flow problem Advances in Optimization and Decision Science for Society, Services and Enterprises (ODS 2019), AIRO Springer Series 3, pp. 23–33, 2019. doi
  13. G. Auricchio, F. Bassetti, S. Gualandi, M. Veneroni. Computing Kantorovich–Wasserstein distances on d-dimensional histograms using (d+1)-partite graphs Advances in Neural Information Processing Systems (NeurIPS 2018), vol. 31, 2018. arXiv
  14. M. Fiasché, D. E. Liberati, S. Gualandi, M. Taisch. Quantum-inspired evolutionary multiobjective optimization for a dynamic production scheduling approach Multidisciplinary Approaches to Neural Computing, Smart Innovation, Systems and Technologies 69, Springer, pp. 191–201, 2018. doi
  15. S. Coniglio, S. Gualandi. On the separation of topology-free rank inequalities for the max stable set problem Proc. International Symposium on Experimental Algorithms (SEA 2017), LIPIcs 75, 29:1–29:13, 2017. doiopen access
  16. G. Galbiati, S. Gualandi. Coloring of paths into forests Proc. Cologne-Twente Workshop on Graphs and Combinatorial Optimization (CTW), pp. 113–116, 2013.
  17. S. Gualandi, M. Lombardi. A simple and effective decomposition for the multidimensional binpacking constraint Proc. Principles and Practice of Constraint Programming (CP 2013), LNCS 8124, pp. 356–364, 2013. doi
  18. M. Lombardi, S. Gualandi. A new propagator for two-layer neural networks in empirical model learning Proc. Principles and Practice of Constraint Programming (CP 2013), LNCS 8124, pp. 448–463, 2013. doi
  19. B. Rostami, F. Malucelli, P. Belotti, S. Gualandi. Quadratic TSP: a lower bounding procedure and a column generation approach Proc. Federated Conference on Computer Science and Information Systems (FedCSIS), pp. 377–384, 2013.
  20. S. Gualandi, F. Malucelli. Resource constrained shortest paths with a super additive objective function Proc. Principles and Practice of Constraint Programming (CP 2012), LNCS 7514, pp. 299–315, 2012. doi
  21. P. Cremonesi, A. Sansottera, S. Gualandi. On the cooling-aware workload placement problem Proc. AAAI Workshop on AI for Data Center Management and Cloud Computing (AIDC), pp. 2–7, 2011.
  22. P. Cremonesi, A. Sansottera, S. Gualandi. Optimizing cooling and server power consumption Proc. IEEE Intl. Conference on Intelligent Computer Communication and Processing (ICCP), pp. 455–462, 2011. doi
  23. M. Chiarandini, G. Galbiati, S. Gualandi. Efficiency issues in the RLF heuristic for graph coloring Proc. Metaheuristics International Conference (MIC 2011), pp. 461–469, 2011.
  24. F. Maffioli, G. Galbiati, S. Gualandi. On minimum changeover cost arborescences Proc. International Symposium on Experimental Algorithms (SEA 2011), LNCS 6630, pp. 112–123, 2011. doi
  25. G. Sangiovanni, F. Amigoni, S. Gualandi. A multiagent system for efficient electrical energy management on the Palamede satellite Proc. International Power Electronics and Motion Control Conference (EPE-PEMC), pp. 39–46, 2010. doi
  26. S. Gualandi, F. Malucelli. Weighted biclique completion via CP-SDP randomized rounding Proc. European Workshop on Mixed Integer Nonlinear Programming (EWMINLP), pp. 223–230, 2010.
  27. S. Gualandi, F. Maffioli, C. Magni. A branch-and-price approach to the k-clustering minimum biclique completion problem Proc. Cologne-Twente Workshop on Graphs and Combinatorial Optimization (CTW), pp. 69–72, 2010.
  28. S. Gualandi, F. Malucelli, D. Sozzi. On the design of the fiber to the home networks Proc. Cologne-Twente Workshop on Graphs and Combinatorial Optimization (CTW), pp. 65–68, 2010.
  29. G. Galbiati, S. Gualandi, F. Maffioli. On minimum reload cost cycle cover Proc. International Symposium on Combinatorial Optimization (ISCO), Electronic Notes in Discrete Mathematics, 36, pp. 81–88, 2010. doi
  30. K. Dhyani, S. Gualandi, P. Cremonesi. A constraint programming approach for the service consolidation problem Proc. CPAIOR 2010, LNCS 6140, pp. 97–101, 2010. doi
  31. S. Gualandi, F. Malucelli, D. Sozzi. On the design of the next generation access networks Proc. CPAIOR 2010, LNCS 6140, pp. 162–175, 2010. doi
  32. E. Amaldi, S. Coniglio, S. Gualandi. Improving cutting plane generation with 0-1 inequalities by bi-criteria separation Proc. International Symposium on Experimental Algorithms (SEA 2010), LNCS 6049, pp. 266–275, 2010. doi
  33. S. Gualandi, F. Malucelli. Graph coloring via constraint programming-based column generation Proc. International Network Optimization Conference (INOC), pp. 1–6, 2009.
  34. S. Gualandi. k-clustering minimum biclique completion via a hybrid CP and SDP approach Proc. CPAIOR 2009, LNCS 5547, pp. 87–101, 2009. doi

Book chapters

  1. A. Capone, I. Filippini, S. Gualandi, D. Yuan. Resource optimization in multiradio multichannel wireless mesh networks In S. Basagni, M. Conti, S. Giordano, I. Stojmenovic (eds.), Mobile Ad Hoc Networking: The Cutting Edge Directions, Wiley, pp. 241–274, 2013. doi

Book translation

  • B. Korte, J. Vygen. Ottimizzazione Combinatoria: Teoria e Algoritmi Italian translation by S. Gualandi of Combinatorial Optimization: Theory and Algorithms. Springer Milano, UNITEXT, 2011. ISBN 978-88-470-1522-7. doi