α-Dominance relation and rough sets in interval-valued information systems

Though rough set has been widely used to study systems characterized by insufficient and incomplete information, its performance in dealing with initial interval-valued data needs to be seriously considered for improving the suitability and scalability. The aim of this paper is to present a parameterized dominance-based rough set approach to interval-valued information systems. First, by considering the degree that an interval-valued data is dominating another one, we propose the concept of alpha-dominance relation. Second, we present the alpha-dominance based rough set model in interval-valued decision systems. Finally, we introduce lower and upper approximate reducts into alpha-dominance based rough set for simplifying decision rules, we also present the judgement theorems and discernibility functions, which describe how lower and upper approximate reducts can be calculated. This study suggests potential application areas and new research trends concerning rough set approach to interval-valued information systems. (C) 2014 Elsevier Inc. All rights reserved.