三支类背景上的规则获取

Rules Acquisition on Three-way Class Contexts

规则提取是三支概念分析中的一个重要问题。首先,基于属性导出三支概念,定义了两种三支类背景,即三支条件类背景和三支决策类背景,给出了类背景上的类概念并且研究了类概念的结构。其次,讨论了三支决策类背景上的类概念与三支弱协调决策形式背景上的属性导出三支概念之间的关系。然后,提出了三支决策类背景上的规则获取方法,并且通过比较证明了基于三支类背景获取的规则优于基于三支弱协调决策形式背景获取的规则。最后,利用三支条件类背景给出了反向规则与双向规则的获取方法。

Rules acquisition is an important problem in three-way concept analysis.Based on attribute-induced three-way concepts,two kinds of three-way class contexts were defined,namely three-way condition class contexts and three-way decision class contexts.The class concepts in these two different three-way class contexts were defined and the structures of class concepts were studied.Moreover,the relationships between the class concepts in three-way decision class contexts and the attribute-induced three-way concepts in three-way weakly consistent formal decision contexts were discussed.Then the rules based on three-way decision class concepts were presented,and the way to acquire them was shown.Furthermore,compared to the rules acquired from the three-way weakly consistent formal decision contexts,the class context based rules were proved to be superior than three-way weakly consistent context based rules.Specifically,the number of class context based rules is smaller than the number of three-way weakly consistent context based rules,but for each three-way weakly consistent context based rule,there exists a class context based rule containing more know-ledge.Finally,considering the three-way condition class context,the reverse rules were defined.Considering both three-way condition class contexts and three-way decision class contexts,the double directed rules were presented.