64 citations · 134 across the 24 of their papers we have counts for
26 papers
Distilling Models of Bounded-Rational Choice: A Constraint Programming Approach
Özgür Akgün, Georgios Gerasimou
We provide an analytical framework that allows for distilling the full explanatory and welfare-relevant content of influential yet computationally hard models of bounded-rational g…
Faster Symmetry Breaking Constraints for Abstract Structures
Özgür Akgün, Mun See Chang, Ian P. Gent +1
In constraint programming and related paradigms, a modeller specifies their problem in a modelling language for a solver to search and return its solution(s). Using high-level mode…
Solver-Aided Expansion of Loops to Avoid Generate-and-Test
Niklas Dewally, Özgür Akgün
Constraint modelling languages like MiniZinc and Essence rely on unrolling loops (in the form of quantified expressions and comprehensions) during compilation. Standard approaches…
Toward Cyclic A.I. Modelling of Self-Regulated Learning: A Case Study with E-Learning Trace Data
Andrew Schwabe, Özgür Akgün, Ella Haig
Many e-learning platforms assert their ability or potential to improve students' self-regulated learning (SRL), however the cyclical and undirected nature of SRL theoretical models…
Breaking the Symmetries of Indistinguishable Objects
Ozgur Akgun, Mun See Chang, Ian P. Gent +1
Indistinguishable objects often occur when modelling problems in constraint programming, as well as in other related paradigms. They occur when objects can be viewed as being drawn…
Automatic Feature Learning for Essence: a Case Study on Car Sequencing
Alessio Pellegrino, Özgür Akgün, Nguyen Dang +2
Constraint modelling languages such as Essence offer a means to describe combinatorial problems at a high-level, i.e., without committing to detailed modelling decisions for a part…
Frugal Algorithm Selection
Erdem Kuş, Özgür Akgün, Nguyen Dang +1
When solving decision and optimisation problems, many competing algorithms (model and solver choices) have complementary strengths. Typically, there is no single algorithm that wor…
Composable Constraint Models for Permutation Enumeration
Ruth Hoffmann, Özgür Akgün, Christopher Jefferson
Constraint programming (CP) is a powerful tool for modeling mathematical concepts and objects and finding both solutions or counter examples. One of the major strengths of CP is th…
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…
Efficient Incremental Modelling and Solving
Gökberk Koçak, Özgür Akgün, Nguyen Dang +1
In various scenarios, a single phase of modelling and solving is either not sufficient or not feasible to solve the problem at hand. A standard approach to solving AI planning prob…
Exploring Instance Generation for Automated Planning
Özgür Akgün, Nguyen Dang, Joan Espasa +3
Many of the core disciplines of artificial intelligence have sets of standard benchmark problems well known and widely used by the community when developing new algorithms. Constra…
Towards Portfolios of Streamlined Constraint Models: A Case Study with the Balanced Academic Curriculum Problem
Patrick Spracklen, Nguyen Dang, Özgür Akgün +1
Augmenting a base constraint model with additional constraints can strengthen the inferences made by a solver and therefore reduce search effort. We focus on the automatic addition…
Enumeration of set-theoretic solutions to the Yang-Baxter equation
Ö. Akgün, M. Mereb, L. Vendramin
We use Constraint Satisfaction methods to enumerate and construct set-theoretic solutions to the Yang-Baxter equation of small size. We show that there are 321931 involutive soluti…
Conjure Documentation, Release 2.3.0
Özgür Akgün, András Salamon
Conjure is an automated modelling tool for Constraint Programming. In this documentation, you will find the following: A brief introduction to Conjure, installation instructions, a…
Towards Improving Solution Dominance with Incomparability Conditions: A case-study using Generator Itemset Mining
Gökberk Koçak, Özgür Akgün, Tias Guns +1
Finding interesting patterns is a challenging task in data mining. Constraint based mining is a well-known approach to this, and one for which constraint programming has been shown…
Memory Consistency Models using Constraints
Ruth Hoffmann, Özgür Akgün, Susmit Sarkar
Memory consistency models (MCMs) are at the heart of concurrent programming. They represent the behaviour of concurrent programs at the chip level. To test these models small progr…
Modelling Langford's Problem: A Viewpoint for Search
Özgür Akgün, Ian Miguel
The performance of enumerating all solutions to an instance of Langford's Problem is sensitive to the model and the search strategy. In this paper we compare the performance of a l…
Solving computational problems in the theory of word-representable graphs
Özgür Akgün, Ian P. Gent, Sergey Kitaev +1
A simple graph is word-representable if there exists a word over the alphabet such that letters and alternate in iff . Word-representable gra…
Declarative Statistics
Roberto Rossi, Özgür Akgün, Steven Prestwich +1
In this work we introduce declarative statistics, a suite of declarative modelling tools for statistical analysis. Statistical constraints represent the key building block of decla…
The BIN_COUNTS Constraint: Filtering and Applications
Roberto Rossi, Özgür Akgün, Steven Prestwich +1
We introduce the BIN_COUNTS constraint, which deals with the problem of counting the number of decision variables in a set which are assigned values that lie in given bins. We illu…
Cloud Benchmarking For Maximising Performance of Scientific Applications
Blesson Varghese, Ozgur Akgun, Ian Miguel +2
How can applications be deployed on the cloud to achieve maximum performance? This question is challenging to address with the availability of a wide variety of cloud Virtual Machi…
Cloud Benchmarking for Performance
Blesson Varghese, Ozgur Akgun, Ian Miguel +2
How can applications be deployed on the cloud to achieve maximum performance? This question has become significant and challenging with the availability of a wide variety of Virtua…