Roland H. C. Yap

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The use of constraint propagation is the main feature of any constraint solver. It is thus of prime importance to manage the propagation in an efficient and effective fashion. There are two classes of propagation algorithms for general constraints: fine-grained algorithms where the removal of a value for a variable will be propagated to the corresponding(More)
A table constraint is explicitly represented as its set of solutions or non-solutions. This ad hoc (or extensional) representation may require space exponential to the arity of the constraint, making enforcing GAC expensive. In this paper, we address the space and time inefficiencies simultaneously by presenting the mddc constraint. mddc is a global(More)
The AC-3 algorithm is a basic and widely used arc consistency enforcing algorithm in Constraint Satisfaction Problems (CSP). Its strength lies in that it is simple, empirically efficient and extensible. However its worst case time complexity was not considered optimal since the first complexity result for AC-3 [Mackworth and Freuder, 1985] with the(More)
In many real-life problems, constraints are explicitly defined as a set of solutions. This ad hoc (table) representation uses exponential memory and makes support checking (for enforcing GAC) difficult. In this paper, we address both problems simultaneously by representing an ad hoc constraint with a multi-valued decision diagram (MDD), a memory efficient(More)
Correct prediction of the translation initiation site (TIS) is an important issue in genomic research. We show that feature generation together with correlation based feature selection can be used with a variety of machine learning algorithms to give highly accurate translation initiation site prediction. Only very few features are needed and the results(More)
An abstract machine is described for the CLP(<inline-equation> <f><sc>R</sc></f> </inline-equation>) programming language. It is intended as a first step toward enabling CLP(<inline-equation> <f><sc>R</sc></f> </inline-equation>) programs to be executed with efficiency approaching that of conventional languages. The core Constraint Logic Arithmetic Machine(More)
A general n-ary constraint is usually represented explicitly as a set of its solution tuples, which may need exponential space. In this paper, we introduce a new representation for general n-ary constraints called Constrained Decision Diagram (CDD). CDD generalizes BDD-style representations and the main feature is that it combines constraint(More)