Biography
I am a Lecturer at the University of St Andrews. My research interests lie in computational combinatorics, graph theory, permutation classes, computational group theory and formal verification.
During my PhD I've investigated the regular language of permutation pattern classes and identified the encodings of sets of permutations with certain properties.
While a researcher I worked on verifying UAV scenarios, memory consistency models, and cache coherence protocols using formal methods, such as model checking. In addition, I have used constraint programming to generate litmus tests for MCMs and CCPs.
More recently, and in line with my main research interests I have been working on improving combinatorial search for graph problems.
Teaching
I teach modules which involve theoretical computer science:
- CS2001 -- Foundations of Computation
- CS1003 -- Programming with Data
Past Teaching:
I used to oversee the Graduate Apprenticeship degree (BSc Data Science) and taught:
- CS3052 -- Computational Complexity
- IS5104 -- Information Security Management
Research areas
My research interests lie in computational combinatorics and group theory, graph theory, permutation classes and formal verification.
In particular, I am interested in engineering efficient algorithms (such as combinatorial search) for graph problems (e.g. subgraph isomorphism problem), group problems (e.g. finding stabiliser chains) and permutation classes (e.g. language of simple permutations).
PhD supervision
- Joseph Loughney
Selected publications
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Open access
Composable constraint models for permutation enumeration
Hoffmann, R., Akgun, O. & Jefferson, C., 22 Jan 2025, In: Discrete Mathematics & Theoretical Computer Science. 26, 1, 25 p.Research output: Contribution to journal › Article › peer-review
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Towards Understanding Differences Between Modelling Pipelines: a Modelers Perspective
Balogh, C., Hoffmann, R. & Espasa Arxer, J., 2 Sept 2024.Research output: Contribution to conference › Paper › peer-review
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Open access
Towards automatic design of factorio blueprints
Patterson, S., Espasa Arxer, J., Chang, M. S. & Hoffmann, R., 27 Aug 2023. 16 p.Research output: Contribution to conference › Paper › peer-review
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Open access
Understanding how people approach constraint modelling and solving
Hoffmann, R., Zhu, X., Akgun, O. & Nacenta, M., 23 Jul 2022, 28th International conference on principles and practice of constraint programming (CP 2022). Solnon, C. (ed.). Dagstuhl: Schloss Dagstuhl- Leibniz-Zentrum fur Informatik GmbH, Dagstuhl Publishing, 18 p. 28. (Leibniz International Proceedings in Informatics (LIPIcs); vol. 235).Research output: Chapter in Book/Report/Conference proceeding › Conference contribution
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Open access
Towards generic explanations for pen and paper puzzles with MUSes
Espasa Arxer, J., Gent, I. P., Hoffmann, R., Jefferson, C., McIlree, M. J. & Lynch, A. M., 2 Jul 2021, Proceedings of the SICSA eXplainable Artifical Intelligence Workshop 2021. Martin, K., Wiratunga, N. & Wijekoon, A. (eds.). p. 56-63 8 p. (CEUR Workshop Proceedings; vol. 2894).Research output: Chapter in Book/Report/Conference proceeding › Conference contribution
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Open access
Using small MUSes to explain how to solve pen and paper puzzles
Espasa Arxer, J., Gent, I. P., Hoffmann, R., Jefferson, C. & Lynch, A. M., 30 Apr 2021.Research output: Working paper › Preprint
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Open access
Collaborative models for autonomous systems controller synthesis
Fraser, D., Giaquinta, R., Hoffmann, R., Ireland, M., Miller, A. & Norman, G., Jul 2020, In: Formal Aspects of Computing. 32, 2-3, p. 157–186 30 p.Research output: Contribution to journal › Article › peer-review
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Open access
Sequential and parallel solution-biased search for subgraph algorithms
Archibald, B., Dunlop, F., Hoffmann, R., McCreesh, C., Prosser, P. & Trimble, J., 2019, Integration of Constraint Programming, Artificial Intelligence, and Operations Research: 16th International Conference, CPAIOR 2019, Thessaloniki, Greece, June 4–7, 2019, Proceedings. Rousseau, L.-M. & Stergiou, K. (eds.). Cham: Springer, p. 20-38 19 p. (Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics); vol. 11494 LNCS).Research output: Chapter in Book/Report/Conference proceeding › Conference contribution
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A continuous-time model of an autonomous aerial vehicle to inform and validate formal verification methods
Ireland, M. L., Hoffmann, R., Miller, A., Norman, G. & Veres, S. M., 19 Mar 2018, (E-pub ahead of print) In: ArXiv e-prints.Research output: Contribution to journal › Article
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Open access
Memory consistency models using constraints
Akgün, Ö., Hoffmann, R. & Sarkar, S., 27 Aug 2018, The Seventeenth Workshop on Constraint Modelling and Reformulation (ModRef 2018), Proceedings. 16 p.Research output: Chapter in Book/Report/Conference proceeding › Conference contribution