Computer Science – Artificial Intelligence
Scientific paper
2011-06-30
Journal Of Artificial Intelligence Research, Volume 21, pages 357-391, 2004
Computer Science
Artificial Intelligence
Scientific paper
10.1613/jair.1351
When writing a constraint program, we have to choose which variables should be the decision variables, and how to represent the constraints on these variables. In many cases, there is considerable choice for the decision variables. Consider, for example, permutation problems in which we have as many values as variables, and each variable takes an unique value. In such problems, we can choose between a primal and a dual viewpoint. In the dual viewpoint, each dual variable represents one of the primal values, whilst each dual value represents one of the primal variables. Alternatively, by means of channelling constraints to link the primal and dual variables, we can have a combined model with both sets of variables. In this paper, we perform an extensive theoretical and empirical study of such primal, dual and combined models for two classes of problems: permutation problems and injection problems. Our results show that it often be advantageous to use multiple viewpoints, and to have constraints which channel between them to maintain consistency. They also illustrate a general methodology for comparing different constraint models.
Hnich Brahim
Smith Barbara M.
Walsh Toby
No associations
LandOfFree
Dual Modelling of Permutation and Injection Problems does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Dual Modelling of Permutation and Injection Problems, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dual Modelling of Permutation and Injection Problems will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-479989