Nico Van Cleemput

Contact Information

Nico Van Cleemput
Ghent University
Department of Applied Mathematics, Computer Science and Statistics
Krijgslaan 281 - S9 - WE02
B-9000 Gent
Belgium
nico.vancleemput@gmail.com

Valencia

Curriculum Vitae

Studies

  • 2001 - 2006: Master of Science in Mathematics, Ghent University, Belgium.
  • 2007 - 2012: PhD in Computer Science, Ghent University, Belgium

Work

  • August 2006 - September 2007: co-worker of GrInvIn-project at Ghent University
  • October 2007 - September 2013: Research assistant at Ghent University
  • November 2013 - December 2014: Research Assistant (postdoc) at University of West Bohemia
  • September 2014 - September 2020: Post-doctoral assistant at Ghent University
  • October 2020 - present: Affiliated researcher at Ghent University (employed outside of academia)

Teaching

I teach / have taught the following courses:

  • Programming (I) (Java) (exercises for the bachelors computer science, mathematics, physics and geography) (2007 - 2012)
  • Programming (II) (Java) (exercises for the bachelors computer science) (2007 - 2013)
  • Computer science (VBA and use of MS Office) (exercises for the bachelors biochemistry/biotechnology, chemistry, geology and geography) (2007 - 2011)
  • Programming (Python) (exercises for the bachelors biochemistry/biotechnology, chemistry, geology and geography) (2011 - 2013)
  • Programming (I) (Java) (exercises for the bachelors computer science, mathematics and physics) (2014 - 2015)
  • Analysis I (for the bachelors computer science) (2015 - 2016)
  • Algorithms and Data-structures 2 (exercises for the bachelors computer science) (2015 - 2020)
  • Calculus (for the bachelors computer science) (2017 - 2020)
  • Structure generation: a four-part course on structure generation taught at University of West-Bohemia during 2014-2015.

Thesis Students

Students I supervised or co-supervised:

Students for whom I assisted the thesis:

Research Interests

  • Generation of structures in chemistry and mathematics
  • Combinatorial geometry
  • Tilings
  • Mathematical conjecturing
  • Development of tools for graph theory
  • General (graph) generation algorithms
  • Graph theory
  • Hamiltonicity and related properties
  • Plane and embedded graphs

Publications

  1. G. Abrishami, F. Rahbarnia, N. Van Cleemput, On non-traceable 3-connected planar cubic graphs of minimum order, Discrete Mathematics, 349 (6) 2026 (DOI).
  2. O.-H. S. Lo, J. M. Schmidt, N. Van Cleemput, C. T. Zamfirescu, Shortness parameters of polyhedral graphs with few distinct vertex degrees, Discrete Mathematics, 348 (8) 2025 (DOI).
  3. N. Bushaw, C. E. Larson, Nico Van Cleemput, Automated Conjecturing for Mathematics Teaching and Research Projects, PRIMUS - Problems, Resources, and Issues in Mathematics Undergraduate Studies, 35 (6) 2025, pp. 636-653 (DOI).
  4. N. Bushaw, V. Gupta, C. E. Larson, S. Loeb, M. Norge, J. Parrish, N. Van Cleemput, J. Yirka and G. Wu, New conditions for graph Hamiltonicity, Involve, 18 (1) 2025, pp. 79-89 (DOI).
  5. P. Brooks, D. Edwards, C.E. Larson, and N. Van Cleemput, Conjecturing-Based Computational Discovery of Patterns in Data, INFORMS Journal on Data Science, 3 (2) 2024, pp. 179-202 (DOI/arXiv).
    • VCU News article
    • INFORMS award: This paper was runner-up for the 2022 INFORMS SAS Data Mining Best Paper Award
    • Podcast: A Google AI-generated podcast describing this research
    • Code Ocean: The Code Ocean capsule of the code for this paper
  6. N. Van Cleemput, C. T. Zamfirescu, Hamiltonian cycles and 1-factors in 5-regular graphs, Journal of Combinatorial Theory, Series B (154), May 2022, pp. 239-261 (DOI/arXiv).
    • Related software: The programs and scripts to reproduce the results of this paper are available on GitHub.
  7. E. Van Nieuwenhuyse, T. Strisciuglio, G. Lorenzo, M. El Haddad, J. Goedgebeur, N. Van Cleemput, C. Ley, A. V. Panfilov, J. de Pooter, Y. Vandekerckhove, R. Tavernier, M. Duytschaever, S. Knecht, N. Vandersickel, Evaluation of Directed Graph-Mapping in Complex Atrial Tachycardias, JACC: Clinical Electrophysiology, 7 (7), July 2021, pp. 936-949 (DOI).
  8. G. Brinkmann, N. Van Cleemput, 4-connected polyhedra have at least a linear number of hamiltonian cycles, European Journal of Combinatorics, 97 2021, 103395 (DOI).
  9. A. P. Burger, J. P. de Wet, M. Frick, N. Van Cleemput, C. T. Zamfirescu, Planar Hypohamiltonian Oriented Graphs, Journal of Graph Theory, 100 (1) 2022, pp. 50-68 (DOI).
    • Related software: The programs and scripts to reproduce the results of this paper are available on GitHub.
  10. I. Fabrici, M. Timkov, T. Madaras, N. Van Cleemput, C. T. Zamfirescu, Non-hamiltonian graphs in which every edge-contracted subgraph is hamiltonian, Applied Mathematics and Computation, 392, 1 March 2021, 125714 (DOI).
    • Related software: The programs to reproduce the results of this paper are available in the perihamiltonian software package.
    • Graphs: The graphs constructed in this paper are available in the Perihamiltonian Graphs section of the House of Graphs.
  11. G. Brinkmann, T. Tucker, N. Van Cleemput, On the genera of polyhedral embeddings of cubic graphs, Discrete Mathematics & Theoretical Computer Science, 23:3 2021, #13 (link).
  12. K. Coolsaet, P. Goetschalckx, N. Van Cleemput, Local Orientation-Preserving Symmetry Preserving Operations on Polyhedra, Discrete Mathematics, 344 (1) 2021 (DOI).
  13. P. Goetschalckx, N. Van Cleemput, K. Coolsaet, Generation of Local Symmetry-Preserving Operations on Polyhedra, Ars Mathematica Contemporanea, 18 (2) 2020, pp. 223-239 (DOI/link).
  14. A. Bradford, J. K. Day, L. Hutchinson, B. Kaperick, C. E. Larson, M. Mills, D. Muncy, N. Van Cleemput, Automated Conjecturing II: Chomp and Reasoned Game Play, Journal of Artificial Intelligence Research (JAIR), 68 2020, pp. 447-461 (DOI).
  15. O.-H. S. Lo, J. M. Schmidt, N. Van Cleemput, C. T. Zamfirescu, Shortness Coefficient of Cyclically 4-Edge-Connected Cubic Graphs, The Electronic Journal of Combinatorics, 27 (1) 2020, P1.43.
  16. N. Vandersickel, E. Van Nieuwenhuyse, N. Van Cleemput, J. Goedgebeur, M. El Haddad, J. De Neve, A. Demolder, T. Strisciuglio, M. Duytschaever and A.V. Panfilov, Directed Networks as a Novel Way to Describe and Analyze Cardiac Excitation: Directed Graph Mapping, Frontiers in Physiology, 10:1138 2019, pp. 14 pages (DOI).
  17. J. Goedgebeur, K. Ozeki, N. Van Cleemput, G. Wiener, On the minimum leaf number of cubic graphs, Discrete Mathematics, 342 (11) 2019, pp. 3000-3005 (DOI/arXiv).
  18. N. Van Cleemput, Hamiltonian-connectedness of triangulations with few separating triangles, Contributions to Discrete Mathematics, 14 (1) 2019, pp. 71-79 (DOI/link).
  19. G. Brinkmann, K. Ozeki, N. Van Cleemput, Types of triangle in plane Hamiltonian triangulations and applications to domination and k-walks, Ars Mathematica Contemporanea, 17 (1) 2019, pp. 51-66 (link).
  20. N. Van Cleemput, C. T. Zamfirescu, Regular Non-Hamiltonian Polyhedral Graphs, Applied Mathematics and Computation, 338 2018, pp. 192-206 (DOI).
    • Pretty as a Picture (Part II): The main finding of this paper was mentioned in the September 2019 Feature Column of the American Mathematical Society, written by Joseph Malkevitch.
  21. K. Ozeki, N. Van Cleemput, C. T. Zamfirescu, Hamiltonian properties in plane graphs with few 3-cuts - a survey, Discrete Mathematics, 341 (9) 2018, pp. 2646-2660 (DOI).
  22. L. Hutchinson, V. Kamat, C. E. Larson, S. Mehta, D. Muncy, and N. Van Cleemput, Automated Conjecturing VI: Domination Number of Benzenoids, MATCH Commun. Math. Comput. Chem., 80 (3) 2018, pp. 821-834 (link).
  23. G. Brinkmann, J. Souffriau, N. Van Cleemput, On the number of hamiltonian cycles in triangulations with few separating triangles, Journal of Graph Theory, 87 (2) 2018, pp. 164-175 (DOI).
  24. C.E. Larson, N. Van Cleemput, Automated Conjecturing I: Fajtlowicz's Dalmatian Heuristic Revisited (Extended Abstract), Proceedings of the 2017 International Joint Conference on Artificial Intelligence (IJCAI-17) 2017, Melbourne.
  25. C.E. Larson, N. Van Cleemput, Automated Conjecturing III: Property-relations conjectures, Annals of Mathematics and Artificial Intelligence, 81 (3) 2017, pp. 315-327 (DOI).
  26. N. Bašić, G. Brinkmann, P.W. Fowler, T. Pisanski, N. Van Cleemput, Sizes of Pentagonal Clusters in Fullerenes, Journal of Mathematical Chemistry, 55 (8) 2017, pp. 1669-1682 (DOI).
  27. G. Brinkmann, J. Souffriau, N. Van Cleemput, On the strongest form of a theorem of Whitney for hamiltonian cycles in plane triangulations, Journal of Graph Theory, 83 (1) 2016, pp. 78-91 (DOI).
  28. C.E. Larson, N. Van Cleemput, Automated Conjecturing I: Fajtlowicz's Dalmatian Heuristic Revisited, Artificial Intelligence, 231 2016, pp. 17-38.
  29. T. Kaiser, M. Saumell, N. Van Cleemput, 10-Gabriel graphs are Hamiltonian, Information Processing Letters, 115 2015, pp. 877-881 (DOI).
  30. G. Brinkmann, C.E. Larson, J. Souffriau, N. Van Cleemput, Construction of planar 4-connected triangulations, Ars Mathematica Contemporanea, 9 (2) 2015, pp. 145-159 (link).
  31. I. Althöfer, J.K. Haugland, K. Scherer, F. Schneider, N. Van Cleemput, Alternating Plane Graphs, Ars Mathematica Contemporanea, 8 (2) 2015, pp. 337-363 (link).
    • Related software: The programs to reproduce the results of this paper are available in the alternating software package.
    • Graphs: The graphs constructed in this paper are available in the Alternating Plane Graphs section of the House of Graphs.
  32. Y. Akama, N. Van Cleemput, Spherical tilings by congruent quadrangles: Forbidden cases and substructures, Ars Mathematica Contemporanea, 8 (2) 2015, pp. 297-318 (link).
  33. G. Brinkmann, J. Goedgebeur, N. Van Cleemput, The history of the generation of cubic graphs, International Journal of Chemical Modeling, 5 (2-3) 2013, pp. 67-89.
  34. C.E. Larson, N. Van Cleemput, Forcing independence, Croat. Chem. Acta, 86 (4) 2013, pp. 469-475 (DOI/link/direct link).
  35. G. Brinkmann, N. Van Cleemput, T. Pisanski, Generation of various classes of trivalent graphs, Theoretical Computer Science, 502 2013, pp. 16-29 (DOI).
    • Related software: The programs to reproduce the results of this paper are available in the pregraphs software package.
  36. G. Brinkmann, N. Van Cleemput, Classification and Generation of Nanocones, Discrete Applied Mathematics, 159 (15) 2011, pp. 1528-1539.
    • Related software: The programs to reproduce the results of this paper are available in the cone software package.
  37. G. Brinkmann, O. Delgado Friedrichs, S. Lisken, A. Peeters, N. Van Cleemput, CaGe - a Virtual Environment for Studying Some Special Classes of Plane Graphs - an Update, MATCH Commun. Math. Comput. Chem., 63 (3) 2010, pp. 533-552 (link).
    • CaGe software: The software described in this paper is available in the CaGe software package.
  38. G. Brinkmann, O. Delgado-Friedrichs, E.C. Kirby, N. Van Cleemput, A Catalogue of Periodic Fully-Resonant Azulene-Transitive Azulenoid Tilings Analogous to Clar Structures, Croat. Chem. Acta, 82 (4) 2009, pp. 781-789 (link/direct link).
    • Related software: The programs to reproduce the results of this paper are available in the azul software package.
  39. A. Peeters, K. Coolsaet, G. Brinkmann, N. Van Cleemput, V. Fack, GrInvIn in a Nutshell, Journal of Mathematical Chemistry, 45 2009, pp. 471-477 (DOI).
PhD Dissertation Cover

PhD Dissertation

On 21 September 2012 I defended my PhD with the title "Generation of structures in chemistry and mathematics". You can find the dissertation on the website of Ghent University at this link.

Conferences & Talks

Talks

  • Educational innovation day of Ghent University (Ghent, Belgium, 10/05/2007): Educational innovation (Dutch): Abstract/Slides
  • 6th Cologne-Twente Workshop on Graphs and Combinatorial Optimization (Enschede, Netherlands, 29-31/05/2007): Plenary talk (with Gunnar Brinkmann): Abstract/Slides
  • MATH / CHEM / COMP (Verbania, Italy, 10-13/06/2008): Toroidal Azulenoids: Abstract/Slides
  • (Informal) Workshop on Structural and Computational Graph Theory (Ghent, Belgium, 20/06/2008): Toroidal Azulenoids: Abstract/Slides
  • Colloquium on Combinatorics (Magdeburg, Germany, 13-14/11/2008): Toroidal Azulenoids: Abstract/Slides
  • 8th Cologne-Twente Workshop on Graphs and Combinatorial Optimization (Paris, France, 02-04/06/2009): Nanocones: A classification result in chemistry: Abstract/Slides
  • MATH / CHEM / COMP (Dubrovnik, Croatia, 08-13/06/2009): Nanocones: A classification result in chemistry: Abstract/Slides
  • Colloquium on Combinatorics (Magdeburg, Germany, 13-14/11/2009): Nanocones: A classification result in chemistry: Abstract/Slides
  • MATH / CHEM / COMP (Dubrovnik, Croatia, 07-12/06/2010): CaGe: A virtual environment for studying some special classes of plane graphs: Abstract/Slides
  • 8th French Combinatorial Conference (Orsay, France, 28/06/2010 - 02/07/2010): Generation of generalized 3-regular graphs: Abstract/Slides
  • Computers in Scientific Discovery 5 (Sheffield, UK, 20-23/07/2010): Generation of generalized 3-regular graphs: Abstract/Slides
  • Colloquium on Combinatorics (Saarbrücken, Germany, 11-13/11/2010): Generation of generalized 3-regular graphs: Abstract/Slides
  • CanaDAM (Victoria, Canada, 31/05/2011-03/06/2011): CaGe: A virtual environment for studying some special classes of plane graphs: Abstract/Slides
  • Informal mini-workshop (Ghent, Belgium, 08/09/2011): Generation of Delaney-Dress symbols: Slides
  • Colloquium on Combinatorics (Magdeburg, Germany, 11-12/11/2011): Generation of Delaney-Dress symbols: Abstract/Slides
  • ICCAM 2012 - International Congress on Computational and Applied Mathematics (Ghent, Belgium, 09-13/07/2012): Nanocones: A classification result in chemistry: Abstract/Slides
  • Computers in Scientific Discovery 6 (Portoroz, Slovenia, 21-25/08/2012): Generation of Delaney-Dress symbols: Abstract/Slides
  • Informal workshop (Ghent, Belgium, 30-31/08/2012): Spherical tilings by congruent quadrangles (black board presentation)
  • PhD defense (Ghent, Belgium, 21/09/2012): : Slides
  • Colloquium on Combinatorics (Berlin, Germany, 16-17/11/2012): Spherical tilings by congruent quadrangles: Abstract/Slides
  • CanaDAM (St.-John's, Canada, 10/06/2013-13/06/2013): Spherical tilings by congruent quadrangles: Abstract/Slides
  • GraphDay@ULB (Brussels, Belgium, 02/10/2013): Hamiltonian cycles in triangulations: Abstract/Slides
  • Graph theory seminar (Pilsen, Czech Republic, 19/11/2013): Hamiltonian cycles in triangulations: Slides
  • Graph theory seminar (Pilsen, Czech Republic, 25/02/2014): Structure generation: Slides
  • ICGT 2014 (Grenoble, France, 30/06/2014 - 04/07/2014): On the strongest form of a theorem of Whitney for hamiltonian cycles in plane triangulations: Slides
  • VCU Discrete Mathematics Seminar (Richmond, USA, 02/09/2014): On the strongest form of a theorem of Whitney for hamiltonian cycles in plane triangulations: Abstract/Slides/Handouts
  • VCU Discrete Mathematics Seminar (Richmond, USA, 09/09/2014): Structure generation - a case study: Abstract/Slides/Handouts
  • CAAGT seminar (Ghent, Belgium, 08/12/2014): Conway's Thrackle Conjecture (black board talk)
  • CAAGT seminar (Ghent, Belgium, 27/03/2015, 03/04/2015, 17/04/2015): Generation of Delaney-Dress symbols (black board talk in three parts)
  • Computers in Scientific Discovery 7 (Richmond, USA, 19-23/07/2015): Classification and generation of nanocones (invited talk): Slides
  • Cycles and Colourings 2015 (Novy Smokovec, Slovakia, 07-11/09/2015): On the number of hamiltonian cycles in triangulations with few separating triangles: Slides
  • Colloquium on Combinatorics (Ilmenau, Germany, 6-7/11/2015): On the strongest form of a theorem of Whitney for hamiltonian cycles in plane triangulations: Abstract/Slides/Handouts
  • VCU Discrete Mathematics Seminar (Richmond, USA, 05/04/2016): On the number of hamiltonian cycles in triangulations with few separating triangles: Abstract/Slides/Handouts
  • Ghent Graph Theory Workshop on Longest Paths and Longest Cycles (Ghent, Belgium, 1-2/08/2016): Connections between decomposition trees of 3-connected plane triangulations and hamiltonian properties (invited talk): Slides/Handouts
  • Colloquium on Combinatorics (Paderborn, Germany, 4-5/11/2016): On the number of hamiltonian cycles in triangulations with few separating triangles: Abstract/Slides/Handouts
  • CAAGT seminar (Ghent, Belgium, 28/04/2017): Type-0 triangles: Slides/Handouts
  • Computers in Scientific Discovery 8 (Mons, Belgium, 23-25/08/2017): Non-hamiltonian and non-traceable regular 3-connected planar graphs: Abstract/Slides/Handouts
  • Colloquium on Combinatorics (Paderborn, Germany, 24-25/11/2017): Non-hamiltonian and non-traceable regular 3-connected planar graphs: Abstract/Slides/Handouts
  • Bucharest Graph Theory Workshop 2018 (Bucharest, Roumania, 15-17/08/2018): Non-hamiltonian and non-traceable regular 3-connected planar graphs (invited talk): Abstract/Slides/Handouts
  • Colloquium on Combinatorics (Paderborn, Germany, 23-24/11/2018): Shortness coefficient of cyclically 4-edge-connected cubic graphs: Abstract/Slides/Handouts
  • 10th Workshop on the Matthews-Sumner Conjecture and related Problems (Pilsen, Czech Republic, 14-19/04/2019): Shortness coefficient of cyclically 4-edge-connected cubic graphs: Abstract/Slides/Handouts
  • Colloquium on Combinatorics (Paderborn, Germany, 20-21/11/2019): 4-connected polyhedra have at least a linear number of hamiltonian cycles: Abstract/Slides/Handouts
  • CAAGT seminar (Ghent, Belgium, 28/10/2019): Hamiltonian cycles and 1-factors in 5-regular graphs (black board talk)
  • CAAGT seminar (Ghent, Belgium, 17/01/2020): 10-Gabriel graphs are hamiltonian (black board talk)

Posters

  • Educational innovation day of Ghent University (10/05/2007) (Dutch): Poster
  • 9th PhD Symposium FirW (04/12/2008): Abstract/Poster
  • Educational innovation day of Ghent University (16/11/2009) (Dutch): Poster

Attended Conferences

Only the conferences where I did not give a presentation:

  • JavaPolis 2007 (Antwerp, Belgium, 12-14/12/2007)
  • Devoxx 2008 (Antwerp, Belgium, 10-12/12/2008)
  • FOSDEM 2009 (Brussels, Belgium, 7-8/02/2009)
  • 5th meeting of the IAMC (Dubrovnik, Croatia, 13-16/06/2009)
  • Devoxx 2009 (Antwerp, Belgium, 18-20/11/2009)
  • FOSDEM 2010 (Brussels, Belgium, 6-7/02/2010)
  • 6th meeting of the IAMC (Dubrovnik, Croatia, 5-6/06/2010)
  • FOSDEM 2011 (Brussels, Belgium, 5-6/02/2011)
  • FOSDEM 2012 (Brussels, Belgium, 4-5/02/2012)
  • FOSDEM 2013 (Brussels, Belgium, 2-3/02/2013)
  • GraphDay@Mons (Mons, Belgium, 5/03/2013)
  • Winter school on Algorithm Design (Beroun, Czech Republic, 12/12/2013 - 15/12/2013)
  • Mathematics in Chemistry meeting (Leipzig, Germany, 26/10/2016 - 28/10/2016)
  • 9th Workshop on the Matthews-Sumner Conjecture and related Problems (Pilsen, Czech Republic, 09/04/2017 - 14/04/2017)
  • Computers in Scientific Discovery 9 (Montreal, Canada, 19/08/2019 - 25/08/2019)
  • Computers in Scientific Discovery 10 (Kortrijk, Belgium, 28/05/2024 - 30/05/2024)
  • Computers in Scientific Discovery 11 (Kranjska Gora, Slovenia, 4/05/2026 - 8/05/2026)

Organised Conferences

Research Visits

  • visit to VCU to work with Craig Larson (Richmond, VA, United States, 22/08/2014 - 15/09/2014)
  • visit to UCLA to work with Stan Schein (Los Angeles, CA, United States, 23/01/2016 - 05/02/2016)
  • visit to VCU to work with Craig Larson (Richmond, VA, United States, 25/03/2016 - 15/03/2016)
  • visit to UCLA to work with Stan Schein (Los Angeles, CA, United States, 19/01/2017 - 27/01/2017)
  • visit to VCU to work with Craig Larson (Richmond, VA, United States, 03/09/2017 - 14/09/2017)
  • visit to UCLA to work with Stan Schein (Los Angeles, CA, United States, 05/04/2018 - 18/04/2018)
  • visit to Salt Rock workshop to work on planar hypohamiltonian oriented graphs (Salt Rock, South-Africa, 26/01/2019 - 05/02/2019)
  • visit to GERAD to work with Gilles Caporossi and Eglantine Camby (Montréal, Canada, 19/08/2019 - 25/08/2019)

Software

Software in which I played a significant role:

CaGe

CaGe

A virtual environment for studying special classes of plane graphs with powerful visualization and generation capabilities.

 CONJECTURING

CONJECTURING

An automated conjecturing system that discovers mathematical relationships and generates conjectures from data.

 Grinvin

Grinvin

Graph invariants tool for exploring and analyzing structural properties of graphs through interactive computation.

 azul

azul

Tools for generating and visualizing toroidal azulenoids.

 cone

cone

Tools for generating and analyzing pseudoconvex polyhedra and nanocone structures in computational chemistry.

 pregraphs

pregraphs

A specialized toolkit for working with pregraph structures in graph theory and combinatorial generation.