Fuzzy information modeling in UML class diagram and relational database models

Computer applications in non-traditional area have put requirement on conceptual data modeling. Some conceptual data models, being the tool of design databases, have been proposed. On one hand, the Unified Modeling Language (UML) can be applied for many areas of software and knowledge engineering, and is being applied to data modeling. On the other hand, information in real world application is often vague or ambiguous. Currently, less research has been done in modeling imprecision and uncertainty in conceptual data model and design of databases with imprecision and uncertainty. In this paper, based on fuzzy set and possibility distribution theory, different levels of fuzziness are introduced into the UML class diagram model and the corresponding formal representations are given. The UML class diagram model is then extended to fuzzy UML data model. The formal mapping of the fuzzy UML data model into the fuzzy relational database schema is proposed in the paper.