关键词: 决策粗糙集, 多粒度粗糙集, 决策代价, 代价认可度

Abstract: Decision-theoretic rough sets and multi-granulation rough sets are two important mechanisms of data processing. On the basis of decision-theoretic rough sets based on multi-cost and multi-granulation rough sets, by considering multi-cost matrix and multi-granularity thought, this paper introduces a weighted mean-cost strategy   into decision-theoretic rough set models, and proposes a multi-granulation decision-theoretic rough set model based on weighted multi-cost. In the incomplete information system, this paper discusses the pessimistic cost decision-theretic rough sets, optimistic cost decision-theoretic rough sets and weighted multi-cost multi-granulation decision-theoretic rough set models respectively, and describes the formulas of the whole decision costs for the above models. Finally, taking the pessimistic multi-granulation decision-theoretic rough set model based on weighted multi-cost for example, this paper analyzes the monotonicity of the decision positive region with respect to knowledge granularity sets, and proposes a definition of the granularity reduction based on the minimum decision cost. The model combines the decision-theoretic rough set model and multi-granulation rough set model with a more suitable method, which can solve the problems from multiple perspectives in the decision-theoretic rough set model.

Key words: decision-theoretic rough set, multi-granulation rough set, decision cost, reliability of cost