文摘
Formal concept analysis is an effective tool for data analysis and knowledge discovery. Corresponding to concept lattice in a formal context, object-oriented concept lattice is introduced based on rough set. Obtaining object-oriented concepts is important but difficult because of the higher time complexity. In order to solve this question, we first divide the power set of the attribute set into the layered sets in this paper. Since for any object-oriented concept, the object-oriented concept extension and object-oriented concept intension determine each other uniquely, we introduce the layered extension sets. By discussing the properties of layered extension sets, the approach to acquire object-oriented concepts is investigated, and related concept acquirement algorithm is also depicted. Examples prove that the concept acquirement approach is valid.