拟单层覆盖上的覆盖粗糙集族

Cover rough sets on a semi-monolayer cover

拟单层覆盖是形式化表示包含缺省值的离散信息表一种有效的方式,同时它也是离散化连续值时,包容误分类对象的理想的数学模型。因为拟单层覆盖是极小且精确的,所以拟单层覆盖上的近似算子较一般的覆盖粗糙近似算子更为特殊。从集合及点集两个角度定义了四种近似算子,并在讨论其性质的基础上,也讨论了这四种近似算子之间的关系。

Semi-monolayer cover is an efficient way to formalize the missing value in information table with discrete values.When system discrete the continuous attribute-values,it is a perfect mathematic model to content the misclassifi-cation object.Because a semi-monolayer cover is the minimal and precise cover,and the approximation operator on the cover is more special than the standard cover rough approximation operator.In this paper,four pairs of approximation operators are defined from two ways.One way starts with the subset of U,other way bases on the set of dot in U. Based on the discussion of their properties,the relations of the four pairs of approximation operators are discussed.