Fuzzy types: A new concept of type for managing vague structures

The requirements of complex applications in the world of object-oriented da tabases have motivated the study of the addition of vagueness to the existi ng models, giving rise to different approaches. The presence of vagueness c an be considered in the type associated to a class, parallel to and indepen dently from a fuzzy view of the set of objects that belong to the class (ex tent of the class). This paper offers a new perspective for representing th e type associated to a class, tackling the problem of vagueness in the data base schema and defining the concept of fuzzy type. Two different component s of these types are defined: the structural component and the behavior com ponent. An adaptation of the mechanism of instantiation and inheritance is presented by considering adequate union operators. A new criterion for hand ling the redefinition capability of the object-oriented data model is expla ined. The description is accompanied by some illustrative examples. (C) 200 0 John Wiley & Sons, Inc.