DESIGNING OPERATORS FOR AN OBJECT - ORIENTED SPATIO - TEMPORAL DATA MODEL Ale RAZA

A spatio-temporal data model consists of data structure, operations and consistency rules. Designing and implementing such model has been a challenging task because of its complexity. This paper focuses on operators for a spatio-temporal model. Two types of operators can be contemplated in this model, i.e., static and dynamic operators. Dynamic operators such as create, kill, destroy and reincarnate, which change the system status are identified. These operators are based on author’s previous work on an object oriented approach to design a unified cell tuple based spatio-temporal data model. Unified Modeling Language (UML) and Object Constraints Language (OCL) are used to design this model. Operations governing the SpatioTemporalClass of this model are discussed here. SpatioTemporalClass is a super-class of ZeroTCellClass, OneTCellClass and TwoTCellClass. Topological notions of point set approach are employed to analyze the various intersections of objects of SpatioTemporalClass. It is demonstrated how the create and kill operators for ZeroTCellClass and OneTCellClass can be constructed in a consistent fashion. Designing these operators may pave the way to design and implement a generic temporal GIS.