Abstract: This paper introduces covering rough sets and Ziarko’s variable precision rough model. Ziarko’s variable precision rough approximation operators are applied to covering approximation space. The concepts of β upper approximation, β lower approximation, β boundary region and β negative region of two kinds of variable precision covering rough set models are given by means of the error parameter β(0≤β<0.5). The basic properties of β upper approximation operator and β lower approximation operator in these two models are discussed. The relation of these two kinds of variable precision covering rough set model and the relation of these two models and other rough sets models are investigated.

Key words: covering, approximation spaces, neighbor region, variable precision covering rough set models

摘要： 介绍覆盖粗糙集和Ziarko变精度粗糙集模型，将Ziarko变精度粗糙近似算子应用于覆盖近似空间，借助引入的误差参数β (0 ≤β<0.5)，给出2种变精度覆盖粗糙集模型的β上近似、β下近似、β边界和β负域的定义。讨论2种模型中β上、下近似算子的基本性质、2种模型之间的关系以及变精度覆盖粗糙集模型与其他粗糙集模型的关系。

关键词: 覆盖, 近似空间, 邻域, 变精度覆盖粗糙集模型

CLC Number: 

• TP18