403 search results - page 70 / 81 » Constraint Databases and Geographic Information Systems |
144
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CCS
2007
ACM
15 years 10 months ago
2007
ACM
In this paper, we study the maintenance of role-based access control (RBAC) models in database environments using transitive closure relations. In particular, the algorithms that ...
118
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ICDT
1995
ACM
15 years 8 months ago
1995
ACM
A tuple t1 of relation R subsumes tuple t2 of R, with respect to a query Q if for every database, tuple t1 derives all, and possibly more, answers to query Q than derived by tuple ...
221
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GIS
2008
ACM
16 years 5 months ago
2008
ACM
We introduce a parallel approximation of an Over-determined Laplacian Partial Differential Equation solver (ODETLAP) applied to the compression and restoration of terrain data use...
150
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GEOINFORMATICA
2008
15 years 4 months ago
2008
Topological relationships like overlap, inside, meet, and disjoint uniquely characterize the relative position between objects in space. For a long time, they have been a focus of...
172
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ARGMAS
2004
Springer
15 years 9 months ago
2004
Springer
Abstract. One of the most difficult problems in multiagent systems involves representing knowledge and beliefs of agents in dynamic environments. New perceptions modify an agent’...