Modelling fuzzy interval-based temporal information: a temporal database perspective

This paper discusses fundamental issues on temporal information in the fuzzy environment and proposes a fuzzy temporal model from a temporal database perspective. Its major aim is to be used as a basic framework to incorporate fuzzy time in temporal databases. The approach is based on Zadeh´s fuzzy set and possibility theories, and discrete time and interval-based concepts. A construction called a temporal specification is introduced to represent temporal knowledge. Information in such a structure can be extracted by six primitive functions. The issue of incompleteness in temporal data is discussed. Allen´s temporal relations and some properties are also studied in the domain of fuzzy temporal knowledge. Finally the author investigates the concepts of union and intersection operations on fuzzy time intervals modelled in the new framework