不完备系统中基于特征相容块的粗糙集

Characteristic consistent blocks based rough set in incomplete system

以同时具有遗漏型和缺席型未知属性值的不完备信息系统为研究对象,分析了由特征关系所得到的特征类中并非任意两个元素都满足容差关系这一不足,将最大相容块技术引入到特征类中,提出了特征相容块的概念,不仅对基于特征相容块的粗糙集的基本性质进行了讨论,而且将特征相容块粗糙集与特征关系粗糙集进行了对比分析,研究结果表明,相比于特征关系,采用特征相容块的方法,可以得到更大的下近似和更小的上近似。

The incomplete information system with both absent and missing unknown values was studied. The limitation of characteristic class, was pointed out such that not any two elements in a characteristic class were mutually tolerant. The technique of maximal consistent blocks was introduced into characteristic class, and then the concept of characteris- tic consistent block was proposed. Not only the basic properties about characteristic consistent blocks based rough set were discussed, but also the relationship between characteristic consistent blocks and characteristic relation based rough sets was analyzed. The results showed that by comparing with the characteristic relation, the greater lower approxima- tion and smaller upper approximation could be obtained by characteristic consistent block approach.