CIRCA Report 2012


CIRCA students
Promotions and New Appointments
Research visits


Steve Linton
Ian Gent
Kevin Hammond
Sophie Huczynska
Ian Miguel
James Mitchell
Martyn Quick
Colva Roney-Dougal
Nik Ruškuc
Max Neunhöffer
Tom Kelsey
Collin Bleak

Senior Research Fellows

Alexander Konovalov
Chris Jefferson
Richard Parker

Research Fellows/Teaching Fellows

Peter Nightingale
Chris Brown
Vladimir Janic
Yann Peresse
Reimer Behrends
Tara Brough
Mikael Vejdemo-Johansson
Jeffrey Burdges


John McDermott
Angela Miguel

Honorary Research Staff

Edmund Robertson
Colin Campbell
John J O’Connor
Roy Dyckhoff

CIRCA Students


Vladimir Janjic
Arthur Geddes 
Jillian McPhee (nee Ferguson)
Lars Kotthoff 
Simon Craik 
Nina Menezes 
Markus Pfeiffer 
Nabilah Abu-Ghazalh 
Ozgur Akgun 
Jennifer Awang
Samuel Baynes
Ruth Hoffmann
Rachael Carey
Alexander McLeman
Anna Schroeder
Arunas Prokopas
Bilal Hussain

Promotions and New Appointments

Bilal Hussain


Markus Pfeiffer
Mikael Vejdemo-Johansson
Lars Kotthoff
Jillian McPhee


Major New Grants in 2011:

  1. Working Together: Constraint Programming and Cloud Computing IJ Miguel, M Dominik, A Barker: EPSRC EP/K015745/1, £630,232, 01/04/2013-31/03/2016.


Complete List of Current CIRCA Grants

  1. Working Together: Constraint Programming and Cloud Computing (2013-2016)
  2. The Structure of Permutation Classes, N Ruskuc (2011-2014)
  3. Solving Word Problems via Generalisations of Small Cancellation, CM Roney-Dougal, M Neunhoeffer, SA Linton (2011-2014).
  4. Representation Theory of Groups, N Ruskuc, (2011-2015)
  5. HPC-GAP: High Performance Computational Algebra and Discrete Mathematics, EPSRC: Linton SA, Gent IP and Hammond K. (2009-2013)
  6. A Constraint Solver Synthesiser, EPSRC: Miguel IJ, Balasubramaniam D, Dent IP, Kelsey T and Linton SA (2009-2014)
  7. Automata, Languages, Decidability in Algebra, EPSRC: Ruskuc N and Quick MR (2010-2013)
  8. EC: SCIEnce: Symbolic Computation Infrastructure for Europe. Linton, S. Hammond, K. (2006-2011)

Research Visits/Invited Talks

  • Nik Ruškuc: research visit to University of Otago in Dunedin, New Zealand; invited speaker at AAA83 conference in Novi Sad, Serbia, 15-18 March; visit to Robert Brignall at Open University 17-20 October; research visit to Lisbon, May
  • Colva Roney-Dougal: visit to University of Padua for 10 days (29th Feb – March 10th); Groups2012 conference in Bielefeld, March 12th – 16th; invited talk at the AMS sectional meeting in Tucson Arizona (October); “Distinguished Visiting Professor” at Bucknell University, visiting Peter Brooksbank (November); QMUL; Warwick; Southampton
  • Nina Menezes: visit to University of Padua for 10 days (29th Feb – March 10th)
  • Max Neunhöffer: Computeralgebra Schwerpunkttagung 2012, Hannover (27.2. – 1. 3.2012)
  • Collin Bleak: Visited New York, USA from 6th – 16th September 2012. Gave a talk at Binghamton University on 13th September and at Cornell University on 11th September.
  • Mikael Vejdemo-Johansson: “Applied and Computational Topology: ATMCS 5” at ICMS (International Centre for Mathematical Sciences), 2th-6th July; Minneapolis/St Paul for the SIAM Annual Meeting (8-14 July); Philadelphia. Visiting collaborators at the University of Pennsylvania (14-18 July); Stanford, Carlsson-Cohen-Madsen-fest (23-27 July); meeting at Schloss Dagstuhl (March 18-23); AMS-MAA Joint Mathematics Meetings in Boston (2-7 Jan); visit to  Colorado State University (8-15 Jan); visit to Stanford and Lawrence/Berkeley National Lab (10 – 15 June)
  • Ian Miguel: Invited talk at 21st International Symposium on Mathematical Programming (ISMP) in Berlin (19-24 August)
  • Peter Nightingale: 21st International Symposium on Mathematical Programming (ISMP) in Berlin (19-24 August)
  • Markus Pfeiffer: invited talk in York
  • Sophie Huczynska: invited speaker at the RICAM-Workshop on Finite Fields and Their Applications: Character Sums and Polynomials, Strobl, Austria, 2-7 September
  • James Mitchell: visit to Saharon Shelah at Rutgers (19-27 October)
  • Tara Brough: visit and invited talk, Aukland, New Zealand (December); invited talk at the 12th NBSAN Meeting, Edinburgh, 23 July; Invited participant in the ICMS workshop on Cubical Complexes and Applications, Edinburgh, 16-20 July; Visited Derek Holt at the University of Warwick, 2 November; Visited Victoria Gould at the University of York and gave a seminar in the York Semigroup, 7 November.


Manuel Delgado (Porto)
Vince Vatter (Florida)
Michael Albert (Otago, New Zealand)
Igor Dolinka (Novi Sad)
James East (Sydney University)
Hayrullah Ayik (Cukurova University, Turkey)
Gonca Ayik (Cukurova University, Turkey)
Frank Luebeck (Aachen)
Daria Policzew (Aberdeen)
Juan-Luis García Zapata
Victoria Gould (York)
Peter Mayr (Linz)
Gracinda Gomes (Lisbon)
Alan Frisch (York)
Andreas Distler (Lisbon)
Andreas Distler (Braunschweig)
George Havas (Queensland)
Alan Cain (Lisbon)
Patrick Prosser (Glasgow)


  1. Albert, M., Atkinson, M., Bouvel, M., Ruskuc, N. & Vatter, V. (2012) Geometric grid classes of permutations In : Transactions of the American Mathematical Society.
  2. Beratarbide, E. & Kelsey, T. (2012) eHealth Governance in Scotland: a cross-sectoral and cross-national comparison In: eHealth: Ethical, Legal and Governance Challenges. Springer, p. 299.
  3. Balasubramaniam, D., Gent, I.P., Jefferson, C., Kotthoff, L., Miguel, I.J. & Nightingale, P. (2012)An Automated Approach to Generating Efficient Constraint Solvers, 34th International Conference on Software Engineering, Zurich, Switzerland, June 2012
  4. Cain, A. J., Ruskuc, N. & Thomas, R. (2012)Unary FA-presentable semigroups In : International Journal of Algebra and Computation.
  5. Distler, A. , Jefferson, C. A. , Kelsey, T. & Kotthoff, L. (2012) The semigroups of order 10 In: Principles and Practice of Constraint Programming: 18th International Conference, CP 2012, Québec City, QC, Canada, October 8-12, 2012. Proceedings. Milano, M. (ed.). Springer, p. 883-899. (Lecture Notes in Computer Science).
  6. Fleming, R. , Kelsey, T. , Anderson, R. , Wallace, H. & Nelson, S. (2012) Interpreting human follicular recruitment and antimullerian hormone concentrations throughout life In : Fertility and Sterility. 98, 5, p. 1097-1102.
  7. Gray, R. & Ruskuc, N. (2012) Maximal subgroups of free idempotent generated semigroups over the full transformation monoid In : Proceedings of the London Mathematical Society.
  8. Gray, R. & Ruskuc, N. (2012) On maximal subgroups of free idempotent generated semigroups In : Israel Journal of Mathematics.
  9. Hyde, J. T., Loughlin, N., Quick, M., Ruskuc, N. & Wallis, A. (2012) On the growth of generating sets for direct powers of semigroups In : Semigroup Forum. 84, 1, p. 116-130.
  10. Kelsey, T. W., Anderson, R. A., Wright, P., Nelson, S. M. & Wallace, W. H. B. (2012) Data-driven assessment of the human ovarian reserve In : Molecular Human Reproduction. 18, 2, p. 79-87.
  11. Kelsey, T. & Wallace, W. H. B. (2012) Ovarian volume correlates strongly with the number of non-growing follicles in the human ovary In : Obstetrics and Gynecology International. 2012
  12. Neunhoeffer, M. & Seress, A. (2012) Constructive Recognition of Classical Groups in their Natural Representation Submitted.
  13. Wallace, H. , Kelsey, T. & Anderson, R. (2012) Ovarian cryopreservation: Experimental or established and a cure for the menopause? In : Reproductive BioMedicine Online. 25, 2, p. 93-95.


CIRCA Preprints

Ian Gent, An Optimality Result on Maintaining List Pointers During Backtracking Search
Peter Nightingale, Ian Gent, Chris Jefferson and Ian Miguel Short and Long Supports for Constraint Propagation