Extension for Explicit Specification of Semantic Generalization

The semantic generalization and the semantic specialization have been proposed. The semantic generalization makes it possible for a shape graph, which corresponds to a relation schema in the relational data model, to have elements by considering the semantics of the elements of the original shape graphs even if there is no common element in the original ones. The element is the lowest common ancestor of the elements of original shape graphs in a hierarchy of concepts rather than their common element. The semantic specialization enables a shape graph to have elements which are different from those of the original shape graphs, but are semantically related to them. This paper extends the semantic generalization in order that the generalized shape graph can be created according to the user´s specification. This enables users to create the generalized shape graphs that users want as in the sematic specialization. This extension also brings us unification of the definitions of the semantic generalization and the semantic specialization.