FUZZY OBJECT-ORIENTED DATA MODEL AND FUZZY ASSOCIATION ALGEBRA

The complexity of real world applications in the fields of intelligent information systems has required fuzzy data models for the representation and the processing of uncertain and imprecise data. In this paper, we propose a new Fuzzy Object Oriented Data model (F-model) and a Fuzzy Association algebra (FA-algebra) for the F-model as a query algebra. The F-model is investigated as a fuzzy extension of an Object Oriented data model which allows fuzzy classes and fuzzy associations. Databases are represented by a fuzzy schema graph at schema level and a fuzzy object graph at object instance level. The FA-algebra operators can operate on the fuzzy association patterns of homogeneous and heterogeneous structures. As the results of fuzzy association operations, the truth values of patterns are returned with the patterns. The completeness of the FA-algebra is shown. In the F-model, we describe the management of fuzzy objects with fuzzy attribute values. Objects representing linguistic terms are proposed for the representation of fuzzy attribute values. The fuzzy objects and the linguistic term objects are uniformly represented by the fuzzy association patterns which are manipulated by the FA-algebra operators. By the FA-algebra, the fuzzy queries involving fuzzy values can be processed easily.