Dr William Pettersson

  • Research Software Engineer (School of Computing Science)

telephone: 0141 330 5456
email: William.Pettersson@glasgow.ac.uk

Room F132, Lilybank Gardens

Import to contacts

ORCID iDhttps://orcid.org/0000-0003-0040-2088

Biography

I am a Research Associate at the School of Computing Science, University of Glasgow. I am working on the IP-MATCH EPSRC project, under the supervision of Dr David Manlove. The goal of such research is to allow the best possible allocation of resources. For instance, one outcome of the project is an allocation of kidney donors to patients, or the allocation of student doctors to hospitals.

Prior to coming to Glasgow, I have lived in various cities in Australia working on parallel exact integer multi-objective optimisation algorithms. I am also an accomplished graph theorist and topologist, specialising in algorithms in graph decompositions and combinatorial topology respectively.

Research interests

Very broadly, I am interested in solving problems with computers. This includes both complexity theory, the theoretical efficiency of an algorithm, as well as the practical running-time efficiency of an algorithm or approach.

Currently I am using integer programming to solve large and complex matching problems under the guidance of Dr David Manlove, and funded by EPSRC grant IP-MATCH. The goal of such research is to allow the best possible allocation of resources. For instance, one outcome of the project is an allocation of kidney donors to patients, or the allocation of student doctors to hospitals.

I have also spent significant time working on a software package called Regina. Regina is a mathematical software suite for combinatorial topologists. This work includes new algorithms, implementation of existing algorithms, and also various user-interface and user-experience updates.

My pet research projects are finding graph decompositions, often through computing. In this, I have researched various theoretical IP and LP techniques (such as constraint generation, Bender's decompositions) as well as more practical issues such as parallelisation techniques and even micro-optimisations in software. My big breakthrough in this area was the completion of the cycle decomposition problem, and I am currently, albeit slowly, working away on the Oberwolfach problem.

To aid various search engines, I here include some key research words and topics that interest me:

  • Parameterised complexity and fixed-parameter tractability
  • Graph algorithms, in particular colourings and decompositions
  • Exact multi-objective integer programming
  • Parallel algorithms
  • Graph decompositions
  • High performance computing

Publications

List by: Type | Date

Jump to: 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2017 | 2015 | 2014
Number of items: 24.

2025

Enright, J. , Meeks, K. , Pettersson, W. and Sylvester, J. (2025) Tangled paths: a random graph model from mallows permutations. Electronic Journal of Combinatorics, (Accepted for Publication)

2024

Enright, J. , Larios-Jones, L., Meeks, K. and Pettersson, W. (2024) Reachability in Temporal Graphs under Perturbation. In: 50th International Conference on Current Trends in Theory and Practice of Computer Science (SOFSEM 2025), Bratislava, Slovakia, 20-23 Jan 2025, (Accepted for Publication)

Ashlagi, I., Cseh, Á., Manlove, D. , Ockenfels, A. and Pettersson, W. (2024) Designing a kidney exchange program in Germany: simulations and recommendations. Central European Journal of Operations Research, (doi: 10.1007/s10100-024-00933-0) (Early Online Publication)

Enright, J. , Lee, D. , Meeks, K. , Sylvester, J. and Pettersson, W. (2024) The complexity of finding and enumerating optimal subgraphs to represent spatial correlation. Algorithmica, (doi: 10.1007/s00453-024-01256-x) (Early Online Publication)

Delorme, M., García, S., Gondzio, J., Kalcsics, J., Manlove, D. and Pettersson, W. (2024) New algorithms for hierarchical optimization in kidney exchange programs. Operations Research, 72(4), pp. 1654-1673. (doi: 10.1287/opre.2022.2374)

2023

Pettersson, W. and Sylvester, J. (2023) Bounds on the twin-width of product graphs. Discrete Mathematics and Theoretical Computer Science, 25(1), 18. (doi: 10.46298/dmtcs.10091)

Enright, J. , Meeks, K. , Pettersson, W. and Sylvester, J. (2023) Cops and robbers on multi-layer graphs. In: Graph-Theoretic Concepts in Computer Science:49th International Workshop, WG 2023, Fribourg, Switzerland, June 28–30, 2023, Revised Selected Papers. Series: Lecture notes in computer science (14093). Springer: Cham. ISBN 9783031433795 (Accepted for Publication)

2022

Pettersson, W. (2022) kep_solver: a Python package for kidney exchange programme exploration. Journal of Open Source Software, 7(80), 4881. (doi: 10.21105/joss.04881)

Delorme, M., García, S., Gondzio, J., Kalcsics, J., Manlove, D. , Pettersson, W. and Trimble, J. (2022) Improved instance generation for kidney exchange programmes. Computers and Operations Research, 141, 105707. (doi: 10.1016/j.cor.2022.105707)

2021

Delorme, M., García, S., Gondzio, J., Kalcsics, J., Manlove, D. and Pettersson, W. (2021) Stability in the hospitals/residents problem with couples and ties: mathematical models and computational studies. Omega, 103, 102386. (doi: 10.1016/j.omega.2020.102386)

Lee, D. , Meeks, K. and Pettersson, W. (2021) Improved inference for areal unit count data using graph-based optimisation. Statistics and Computing, 31(4), 51. (doi: 10.1007/s11222-021-10025-7)

Biró, P. et al. (2021) Modelling and optimisation in European kidney exchange programmes. European Journal of Operational Research, 291(2), pp. 447-456. (doi: 10.1016/j.ejor.2019.09.006)

Pettersson, W. , Delorme, M., García, S., Gondzio, J., Kalcsics, J. and Manlove, D. (2021) Improving solution times of stable matching problems through preprocessing. Computers and Operations Research, 128, 105128. (doi: 10.1016/j.cor.2020.105128)

Smeulders, B. et al. (2021) Data and optimization requirements for Kidney Exchange Programs. Health Informatics Journal, 27(2), pp. 1-15. (doi: 10.1177/14604582211009918) (PMID:33878984)

Enright, J. , Lee, D. , Meeks, K. , Pettersson, W. and Sylvester, J. (2021) The complexity of finding optimal subgraphs to represent spatial correlation. In: Du, Ding-Zhu, Du, Donglei, Wu, Chenchen and Xu, Dachuan (eds.) Combinatorial Optimization and Applications. Series: Lecture Notes in Computer Science (13135). Springer, pp. 152-166. ISBN 9783030926809 (doi: 10.1007/978-3-030-92681-6_13)

2020

Pettersson, W. and Ozlen, M. (2020) Multi-objective integer programming: synergistic parallel approaches. INFORMS Journal on Computing, 32(2), pp. 461-472. (doi: 10.1287/ijoc.2018.0875)

2019

Delorme, M., Garcia, S., Gondzio, J., Kalcsics, J., Manlove, D. and Pettersson, W. (2019) Mathematical models for stable matching problems with ties and incomplete lists. European Journal of Operational Research, 277(2), pp. 426-441. (doi: 10.1016/j.ejor.2019.03.017)

McCreesh, C. , Pettersson, W. and Prosser, P. (2019) Understanding the empirical hardness of random optimisation problems. In: 25th International Conference on Principles and Practice of Constraint Programming, Stamford, CT, USA, 30 Sep - 04 Oct 2019, pp. 333-349. (doi: 10.1007/978-3-030-30048-7_20)

2017

Pettersson, W. and Ozlen, M. (2017) A parallel approach to bi-objective integer programming. ANZIAM Journal, 58, C69-C81. (doi: 10.21914/anziamj.v58i0.11724)

Burton, B., Cabello, S., Kratsch, S. and Pettersson, W. (2017) The Parameterized Complexity of Finding a 2-Sphere in a Simplicial Complex. In: 34th Symposium on Theoretical Aspects of Computer Science (STACS 2017), Hannover, Germany, 8-11 March 2017, 18:1-18:14. ISBN 9783959770286 (doi: 10.4230/LIPIcs.STACS.2017.18)

2015

Bryant, D., Danziger, P. and Pettersson, W. (2015) Bipartite 2-ractorizations of complete multipartite graphs. Journal of Graph Theory, 78(4), pp. 287-294. (doi: 10.1002/jgt.21806)

Burton, B. A. and Pettersson, W. (2015) An Edge-Based Framework for Enumerating 3-Manifold Triangulations. In: 31st International Symposium on Computational Geometry (SoCG 2015), Eindhoven, The Netherlands, 22-25 June 2015, pp. 270-284. ISBN 9783939897835 (doi: 10.4230/LIPIcs.SOCG.2015.270)

2014

Bryant, D., Horsley, D. and Pettersson, W. (2014) Cycle decompositions V: Complete graphs into cycles of arbitrary lengths. Proceedings of the London Mathematical Society, 108(5), pp. 1153-1192. (doi: 10.1112/plms/pdt051)

Burton, B. A. and Pettersson, W. (2014) Fixed Parameter Tractable Algorithms in Combinatorial Topology. In: International Computing and Combinatorics Conference (COCOON 2014), Atlanta, GA, USA, 4-6 Aug 2014, pp. 300-311. ISBN 9783319087825 (doi: 10.1007/978-3-319-08783-2_26)

This list was generated on Thu Apr 24 20:07:18 2025 BST.
Jump to: Articles | Book Sections | Conference Proceedings
Number of items: 24.

Articles

Enright, J. , Meeks, K. , Pettersson, W. and Sylvester, J. (2025) Tangled paths: a random graph model from mallows permutations. Electronic Journal of Combinatorics, (Accepted for Publication)

Ashlagi, I., Cseh, Á., Manlove, D. , Ockenfels, A. and Pettersson, W. (2024) Designing a kidney exchange program in Germany: simulations and recommendations. Central European Journal of Operations Research, (doi: 10.1007/s10100-024-00933-0) (Early Online Publication)

Enright, J. , Lee, D. , Meeks, K. , Sylvester, J. and Pettersson, W. (2024) The complexity of finding and enumerating optimal subgraphs to represent spatial correlation. Algorithmica, (doi: 10.1007/s00453-024-01256-x) (Early Online Publication)

Delorme, M., García, S., Gondzio, J., Kalcsics, J., Manlove, D. and Pettersson, W. (2024) New algorithms for hierarchical optimization in kidney exchange programs. Operations Research, 72(4), pp. 1654-1673. (doi: 10.1287/opre.2022.2374)

Pettersson, W. and Sylvester, J. (2023) Bounds on the twin-width of product graphs. Discrete Mathematics and Theoretical Computer Science, 25(1), 18. (doi: 10.46298/dmtcs.10091)

Pettersson, W. (2022) kep_solver: a Python package for kidney exchange programme exploration. Journal of Open Source Software, 7(80), 4881. (doi: 10.21105/joss.04881)

Delorme, M., García, S., Gondzio, J., Kalcsics, J., Manlove, D. , Pettersson, W. and Trimble, J. (2022) Improved instance generation for kidney exchange programmes. Computers and Operations Research, 141, 105707. (doi: 10.1016/j.cor.2022.105707)

Delorme, M., García, S., Gondzio, J., Kalcsics, J., Manlove, D. and Pettersson, W. (2021) Stability in the hospitals/residents problem with couples and ties: mathematical models and computational studies. Omega, 103, 102386. (doi: 10.1016/j.omega.2020.102386)

Lee, D. , Meeks, K. and Pettersson, W. (2021) Improved inference for areal unit count data using graph-based optimisation. Statistics and Computing, 31(4), 51. (doi: 10.1007/s11222-021-10025-7)

Biró, P. et al. (2021) Modelling and optimisation in European kidney exchange programmes. European Journal of Operational Research, 291(2), pp. 447-456. (doi: 10.1016/j.ejor.2019.09.006)

Pettersson, W. , Delorme, M., García, S., Gondzio, J., Kalcsics, J. and Manlove, D. (2021) Improving solution times of stable matching problems through preprocessing. Computers and Operations Research, 128, 105128. (doi: 10.1016/j.cor.2020.105128)

Smeulders, B. et al. (2021) Data and optimization requirements for Kidney Exchange Programs. Health Informatics Journal, 27(2), pp. 1-15. (doi: 10.1177/14604582211009918) (PMID:33878984)

Pettersson, W. and Ozlen, M. (2020) Multi-objective integer programming: synergistic parallel approaches. INFORMS Journal on Computing, 32(2), pp. 461-472. (doi: 10.1287/ijoc.2018.0875)

Delorme, M., Garcia, S., Gondzio, J., Kalcsics, J., Manlove, D. and Pettersson, W. (2019) Mathematical models for stable matching problems with ties and incomplete lists. European Journal of Operational Research, 277(2), pp. 426-441. (doi: 10.1016/j.ejor.2019.03.017)

Pettersson, W. and Ozlen, M. (2017) A parallel approach to bi-objective integer programming. ANZIAM Journal, 58, C69-C81. (doi: 10.21914/anziamj.v58i0.11724)

Bryant, D., Danziger, P. and Pettersson, W. (2015) Bipartite 2-ractorizations of complete multipartite graphs. Journal of Graph Theory, 78(4), pp. 287-294. (doi: 10.1002/jgt.21806)

Bryant, D., Horsley, D. and Pettersson, W. (2014) Cycle decompositions V: Complete graphs into cycles of arbitrary lengths. Proceedings of the London Mathematical Society, 108(5), pp. 1153-1192. (doi: 10.1112/plms/pdt051)

Book Sections

Enright, J. , Meeks, K. , Pettersson, W. and Sylvester, J. (2023) Cops and robbers on multi-layer graphs. In: Graph-Theoretic Concepts in Computer Science:49th International Workshop, WG 2023, Fribourg, Switzerland, June 28–30, 2023, Revised Selected Papers. Series: Lecture notes in computer science (14093). Springer: Cham. ISBN 9783031433795 (Accepted for Publication)

Enright, J. , Lee, D. , Meeks, K. , Pettersson, W. and Sylvester, J. (2021) The complexity of finding optimal subgraphs to represent spatial correlation. In: Du, Ding-Zhu, Du, Donglei, Wu, Chenchen and Xu, Dachuan (eds.) Combinatorial Optimization and Applications. Series: Lecture Notes in Computer Science (13135). Springer, pp. 152-166. ISBN 9783030926809 (doi: 10.1007/978-3-030-92681-6_13)

Conference Proceedings

Enright, J. , Larios-Jones, L., Meeks, K. and Pettersson, W. (2024) Reachability in Temporal Graphs under Perturbation. In: 50th International Conference on Current Trends in Theory and Practice of Computer Science (SOFSEM 2025), Bratislava, Slovakia, 20-23 Jan 2025, (Accepted for Publication)

McCreesh, C. , Pettersson, W. and Prosser, P. (2019) Understanding the empirical hardness of random optimisation problems. In: 25th International Conference on Principles and Practice of Constraint Programming, Stamford, CT, USA, 30 Sep - 04 Oct 2019, pp. 333-349. (doi: 10.1007/978-3-030-30048-7_20)

Burton, B., Cabello, S., Kratsch, S. and Pettersson, W. (2017) The Parameterized Complexity of Finding a 2-Sphere in a Simplicial Complex. In: 34th Symposium on Theoretical Aspects of Computer Science (STACS 2017), Hannover, Germany, 8-11 March 2017, 18:1-18:14. ISBN 9783959770286 (doi: 10.4230/LIPIcs.STACS.2017.18)

Burton, B. A. and Pettersson, W. (2015) An Edge-Based Framework for Enumerating 3-Manifold Triangulations. In: 31st International Symposium on Computational Geometry (SoCG 2015), Eindhoven, The Netherlands, 22-25 June 2015, pp. 270-284. ISBN 9783939897835 (doi: 10.4230/LIPIcs.SOCG.2015.270)

Burton, B. A. and Pettersson, W. (2014) Fixed Parameter Tractable Algorithms in Combinatorial Topology. In: International Computing and Combinatorics Conference (COCOON 2014), Atlanta, GA, USA, 4-6 Aug 2014, pp. 300-311. ISBN 9783319087825 (doi: 10.1007/978-3-319-08783-2_26)

This list was generated on Thu Apr 24 20:07:18 2025 BST.

Research datasets

Jump to: 2025 | 2024 | 2021 | 2020 | 2019 | 2018
Number of items: 9.

2025

Pettersson, W. (2025) Operational research approaches and mathematical models for kidney exchange: A literature survey and empirical evaluation. [Data Collection]

2024

Pettersson, W. (2024) Designing a Kidney Exchange Program in Germany: Simulations and Recommendations. [Data Collection]

2021

Delorme, M., Garcia, S., Gondzio, J., Kalcsics, J., Manlove, D. , Pettersson, W. and Trimble, J. (2021) Improved instance generation for kidney exchange programmes. [Data Collection]

Delorme, M., García, S., Gondzio, J., Kalcsics, J., Manlove, D. , Pettersson, W. and Trimble, J. (2021) A new matheuristic and improved instance generation for kidney exchange programmes. [Data Collection]

2020

Pettersson, W. , Delorme, M., García, S., Gondzio, J., Kalcsics, J. and Manlove, D. (2020) Enhanced mathematical models for hierarchical optimisation in kidney exchange programmes. [Data Collection]

Pettersson, W. , Delorme, M., García, S., Gondzio, J., Kalcsics, J. and Manlove, D. (2020) Stability definitions for the Hospitals / Residents problem with Couples and Ties: Mathematical models and computational studies. [Data Collection]

2019

Pettersson, W. , Delorme, M., García, S., Gondzio, J., Kalcsics, J. and Manlove, D. (2019) Improving solution times of stable matching problems through preprocessing. [Data Collection]

2018

Pettersson, W. (2018) Multi-objective integer programming: Synergistic parallel approaches. [Data Collection]

Delorme, M., García, S., Gondzio, J., Kalcsics, J., Pettersson, W. and Manlove, D. (2018) Mathematical models for stable matching problems with ties and incomplete lists. [Data Collection]

This list was generated on Fri Apr 25 12:46:05 2025 BST.

Additional information

I have previously worked on parallel algorithms for exact multi-objective integer optimisation with A.Prof Melih Ozlen. In this work, I implemented the following parallel algorithms

moip_aira - An implementation of EPP, SPREAD and CLUSTER, as detailed in <forthcoming>

boxfinder - An implementation of the algorithm from Kerstin Dächert, Kathrin Klamroth (2015). A linear bound on the number of scalarizations needed to solve discrete tricriteria optimization problems. Journal of Global Optimization, 61(4), 643--676

kppm - An implementation of the algorithm from C. Dhaenens, , J. Lemesre, E.G. Talbi (2008). K-PPM: A new exact method to solve multi-objective combinatorial optimization problems. European Journal of Operational Research, 200(1), 45-53.

I am also a developer of Regina, a suite of mathematical software for combinatorial topologists.


A photo of William Pettersson