分级粗糙集和分级知识约简

Pawlak 粗糙集模型认为一个元素要么属于一个集合,要么不属于该集合,要么可能属于该集合,把可能属于该集合的元素的全体称为边界.Pawlak 粗糙集模型对边界的研究较少.文章认为对边界的隶属度差别较小的元素以同一个量级属于边界,从而可按一个对象对边界的隶属量级对边界进行划分.基于这一思想提出了分级粗糙集模型和分级最大分布约简、分级分布约简的概念.给出了这两种约简的判定定理及辨识矩阵以及相应的核属性的等价条件.分级粗糙集模型推广了Pawlak粗糙集及变精度粗糙集模型.

Band Rough Set and Band Knowledge Reduction

In Pawlak rough set model,an element is in a set,or not in the set,or possibly in the set.A subset of objects,possibly in the set is called boundary of the set.In the research on Pawlak rough set model,less is paid to the research of the boundary issue.In this paper,two objects with a few minor differences in the degree of membership in a set are viewed in the same level.From this view a partition of the boundary of a rough set is obtained and the concepts of band rough set and band distribution reduction a...