Dynamic maintenance of three-way decision rules

Abstract

Decision-theoretic rough sets provide a three-way decision framework for approximating a target concept, with an error-tolerance capability to handle uncertainty problems by using a pair of thresholds on probability. The three-way decision rules of acceptance, rejection and deferment decisions can be derived directly from the three regions implied by rough set approximations. The decision environment is prone to dynamic instead of static in reality. With the data changed continuously, the three regions of a target decision will be changed inevitably, while the induced three-way decision rules will be changed avoidably. In this paper, we discuss the dynamic maintenance principles of three-way decision rules based on the variation of three regions with an incremental object. Decision rules can be updated incrementally without re-computing rule sets from the very beginning when a new object is added up to an information system.