Formal concept analysis in hybrid relational databases

Relational Database Model (RDM) has been proven to be a very useful data-storage technique. As information is stored as data in relational databases, the induction of concepts from data is a pivotal topic in the data mining field. Formal Concept Analysis (FCA) turns out to be a perfect instrument for a meaningful and conceptual exploration of the stored data. However, many databases in practice are often hybrid ones. This paper proposes an approach towards extracting concepts from hybrid relations, which preserve the RDM and allow complex values such as relations in columns for relations. The method can be described as follows: the sub-tuples/subattributes pairs are regard as new attributes and inserted into a main relation, and we further obtain a new complex relation called a target relation from which concepts can be extracted. The insertion operation is semantics-preserving and extent-preserving. In addition, this paper analyzed the structural connections among concept lattices in detail, which can be used to construct a complex concept lattice from simple ones. The method may reduce time complexity of constructing the concept lattice of a complex relation. © 2012 Praise Worthy Prize S.r.l. - All rights reserved.