13 citations · 35 across the 12 of their papers we have counts for
13 papers
Athanor: Local Search over Abstract Constraint Specifications
Saad Attieh, Nguyen Dang, Christopher Jefferson +2
Local search is a common method for solving combinatorial optimisation problems. We focus on general-purpose local search solvers that accept as input a constraint model - a declar…
Towards a Model of Puzznic
Joan Espasa, Ian P. Gent, Ian Miguel +3
We report on progress in modelling and solving Puzznic, a video game requiring the player to plan sequences of moves to clear a grid by matching blocks. We focus here on levels wit…
Challenges in Modelling and Solving Plotting with PDDL
Joan Espasa, Ian Miguel, Peter Nightingale +2
We study a planning problem based on Plotting, a tile-matching puzzle video game published by Taito in 1989. The objective of this game is to remove a target number of coloured blo…
Learning to Select SAT Encodings for Pseudo-Boolean and Linear Integer Constraints
Felix Ulrich-Oltean, Peter Nightingale, James Alfred Walker
Many constraint satisfaction and optimisation problems can be solved effectively by encoding them as instances of the Boolean Satisfiability problem (SAT). However, even the simple…
A Framework for Generating Informative Benchmark Instances
Nguyen Dang, Özgür Akgün, Joan Espasa +2
Benchmarking is an important tool for assessing the relative performance of alternative solving approaches. However, the utility of benchmarking is limited by the quantity and qual…
TabID: Automatic Identification and Tabulation of Subproblems in Constraint Models
Özgür Akgün, Ian P. Gent, Christopher Jefferson +5
The performance of a constraint model can often be improved by converting a subproblem into a single table constraint (referred to as tabulation). Finding subproblems to tabulate i…
Towards Reformulating Essence Specifications for Robustness
Özgür Akgün, Alan M. Frisch, Ian P. Gent +4
The Essence language allows a user to specify a constraint problem at a level of abstraction above that at which constraint modelling decisions are made. Essence specifications are…
SAT Encodings for Pseudo-Boolean Constraints Together With At-Most-One Constraints
Miquel Bofill, Jordi Coll, Peter Nightingale +3
When solving a combinatorial problem using propositional satisfiability (SAT), the encoding of the problem is of vital importance. We study encodings of Pseudo-Boolean (PB) constra…
A Review of Literature on Parallel Constraint Solving
Ian P. Gent, Ciaran McCreesh, Ian Miguel +4
As multicore computing is now standard, it seems irresponsible for constraints researchers to ignore the implications of it. Researchers need to address a number of issues to explo…
Generalized Support and Formal Development of Constraint Propagators
James Caldwell, Ian P. Gent, Peter Nightingale
Constraint programming is a family of techniques for solving combinatorial problems, where the problem is modelled as a set of decision variables (typically with finite domains) an…
S-crucial and bicrucial permutations with respect to squares
Ian Gent, Sergey Kitaev, Alexander Konovalov +2
A permutation is square-free if it does not contain two consecutive factors of length two or more that are order-isomorphic. A permutation is bicrucial with respect to squares if i…
Qualitative Modelling via Constraint Programming: Past, Present and Future
Thomas W. Kelsey, Lars Kotthoff, Christoffer A. Jefferson +4
Qualitative modelling is a technique integrating the fields of theoretical computer science, artificial intelligence and the physical and biological sciences. The aim is to be able…
Machine learning for constraint solver design -- A case study for the alldifferent constraint
Ian Gent, Lars Kotthoff, Ian Miguel +1
Constraint solvers are complex pieces of software which require many design decisions to be made by the implementer based on limited information. These decisions affect the perform…