Rules Acquisition And Attribute Reduction Of Ordered Formal Decision Contexts

With the data growth in the database,formal concept analysis theory provides an important theoretical basis for data mining and knowledge acquisition.The formal decision context is one of the main research subjects of formal concept analysis,rules acquisition and attribute reduction based on a formal decision context can obtain information quickly and efficiently.Therefore,rules acquisition and attribute reduction are two important research topics of formal concept analysis theory.On the basis of the formal decision contexts that contain multi-valued decision information,the concept of the ordered formal decision context is proposed by this paper,and the correlation theory of the ordered decision concept lattice is proposed as well.Main contents of the thesis include:1.Based on the multi-valued formal decision context,the formal context and information system are combined to construct the ordered formal decision context,then the ordered decision concept and the ordered decision concept lattice are defined by this paper,furthermore,the properties of the ordered formal decision context are studied;2.Rules acquisition on the ordered formal decision context are conducted,the confidence level and the support degree are used as the reference to obtaine effective information,then the practical significance of rule’s confidence level is analyzed through a concrete example;3.Based on the ordered formal decision contexts,the attribute reduction is conducted,and the definition of the rule-preserved attribute reduction as well as the lattice structure-preserved reduction are proposed,meanwhile the relationship between the two reducts is discussed;4.The relationship between the ordered decision concept lattices and the classical concept lattices is studied.