关键词: 变精度, 覆盖, 决策信息系统, 约简

Abstract: The variable precision method is introduced into the covering decision information system. Definitions of the variable precision covering lower and upper approximations are given. Some properties and reductions of them are discussed. Their relationships with the covering distribution’s reduction, the largest covering distribution’s reduction and the covering lower and upper approximations’ reduction are analyzed. Examples are given to illustrate the conclusions.

Key words: variable precision, covering, decision information system, reduction