Generalized Bitemporal Constructors for A Fuzzily-Bounded Time Interval Model

摘要

Bitemporal constructors are important operators to be processed in queries against a temporal database. In our recent work [7], their processing has been proposed in the context of a fuzzy interval-based temporal model [6]. However, such a method can be carried out only under a restriction known as the definability of the operations. This constraint limits their expressive power as well as the scope of their applicability. Therefore, in this paper, we will present a generalization of the bitemporal constructors by relaxing such a restriction. This can be achieved by introducing the concept of a null interval for the case of the intersection operation and the notion of a conjunctive specification for the union operation.