【摘要】 在集值决策信息系统中定义了一种相容关系,利用最大相容类定义了两类上下近似算子;分别利用两类下近似算子,定义了属性的A-相对约简和E-相对约简,以获取确定性决策规则的优化规则;分别定义了两种区分函数,相应地给出了A-相对约简和E-相对约简的区分函数求法,并证明了该方法的正确性。更多还原

【Abstract】 In set-valued decision information systems,some objects may possess more than one attribute values for an attribute.A tolerance relation and two kinds of lower and upper approximation operators are defined by use of maximal tolerance classes,and two kinds of attribute reduction are derived accordingly,that is,A-relative reduction and E-relative reduction,so as to get the optimal definite decision rules.In order to compute A-relative reduction and E-relative reduction,two discernibility functions are defined respectively,and the computation approaches of these two kinds of attribute reduction are proved and exemplified.更多还原