The Reduction Of The Multi - Valued Background And The Reduction Of The Dominant Background

In recent years, with the development of database technology, large amounts of data are accumulated. Formal concept analysis, which takes concept lattice as the core data structure, has become an effective tool for data analysis and data processing. At present, the studies of formal concept analysis mainly focus on single-valued formal context, but in our real life the formal context needed to be addressed is often with multi-value. Therefore, the study of many-valued formal context is one of the important research areas in formal concept analysis.In this thesis, the attribute reduction of many-valued formal context is studied. We mainly study the attribute reduction of many-valued formal context which is based on the equivalence relations and the attribute reduction of many-valued ordered formal context which is based on the dominance relations.The content can be summarized as follows:1. For a discrete numerical many-valued formal context, the many-valued division consistent set and many-valued division reduction based on equivalence relations are proposed. Furthermore, the approach to many-valued division reduction and the judgment theorem of the attribute characters are presented and the relation between the division reduction of many-valued formal context and the division reduction of information systems division reduction is obtained.2. For the ordered formal context, the dominance consistent set and dominance attribute reduction which are based on dominance relations are proposed. Then a method to finding the dominance reduction and the theorem of attribute characters are presented. Finally the relation between dominance reduction of ordered formal context and the reduction of ordered information systems is obtained.