Geographic information systems gis have become important tools in public planning activities (e.g, in environmental or utility management). This type of activity requires the creation and management of alternative scenarios, as well as analysis of temporal data evolution. Existing systems provide limited support for these operations, and appropriate tools are yet to be developed. This paper pre...

In data grid, using reservation is accepted to provide scheduling and service quality. Users need to have an access to the stored data in geographical environment, which can be solved by using replication, and an action taken to reach certainty. As a result, users are directed toward the nearest version to access information. The most important point is to know in which sites and distributed sy...

In this paper, we propose a model of versions which manages simple and composite objects. In our model, we have identified two types of versions : class versions [ 101 [24] and instance versions [6] [8]. These different versions are linked to each other by different relationships. A mechanism for the automatic propagation of versions [13] [24] for composite objects is proposed in order to propa...