Feedback Extension-enveloping in Factor Spaces and Its Improvements
Wang Hua-don · Mohu xitong yu shuxue · 2015
This paper aims to study the two approximate methods about the extension of concept,i.e.,outer-enveloping and inner-enveloping of feedback extension.First,we construct the two approximations at the sight of the concept itself and its inverse concept.Then we discuss the relationship between the approximations and upper and lower approximations in the rough set theory.It reveals that they have consistency.Some related properties existing between the two envelopes are showed.Subsequently,we also discuss the precision problems of the envelopes in approximating the extension of concept and then four improve methods are proposed.