【摘要】 覆盖粗糙集是经典粗糙集的推广,从不同的角度研究覆盖粗糙上近似,就有不同的上近似定义方法。本文将同一覆盖元中的元素理解为相关,从元素相关性角度研究覆盖粗糙集上近似,从点与集合的依赖关系入手,提出覆盖粗糙集阶的概念及覆盖粗糙集依赖上近似的概念,并对覆盖粗糙集的依赖上近似进行分析。从覆盖意义上说,相对于其它上近似,依赖上近似具有覆盖元数量较少的特点,而且具有上近似可定义的特点。更多还原

【Abstract】 Covering rough sets theory is an extension to classical rough sets.There are many ways to define covering rough upper approximation.Different points of view lead to different definitions in studying covering upper approximation.This paper proposes a concept called elements relationship,and by using the concept it defines covering rough sets upper approximation named element-dependent upper approximation.Different from other upper approximation,a dependency upper approximation is a definable set,and from the view of covering,it has the property of less covering-element numbers compared with other covering upper approximation.更多还原