Magic Rewritings for Efficiently Processing Reactivity on Web Ontologies
OTM '08 Proceedings of the OTM 2008 Confederated International Conferences, CoopIS, DOA, GADA, IS, and ODBASE 2008. Part II on On the Move to Meaningful Internet Systems
Engineering parallel in-place random generation of integer permutations
WEA'08 Proceedings of the 7th international conference on Experimental algorithms
Expressing and managing reactivity in the semantic web
OTM'10 Proceedings of the 2010 international conference on On the move to meaningful internet systems: Part II
Expressing and managing reactivity in the semantic web
OTM'10 Proceedings of the 2010 international conference on On the move to meaningful internet systems: Part II
A comparison of three algorithms for approximating the distance distribution in real-world graphs
TAPAS'11 Proceedings of the First international ICST conference on Theory and practice of algorithms in (computer) systems
Index design and query processing for graph conductance search
The VLDB Journal — The International Journal on Very Large Data Bases
Finding top-k shortest path distance changes in an evolutionary network
SSTD'11 Proceedings of the 12th international conference on Advances in spatial and temporal databases
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Computing transitive closure and reachability information in directed graphs is a fundamental graph problem with many applications. The fastest known algorithms run in O(sm) time for computing all nodes reachable from each of 1/spl les/s/spl les/n source nodes, or, using fast matrix multiplication, in O(n/sup 2.38/) time for computing the transitive closure, where n is the number of nodes and m the number of edges in the graph. In query optimization in database applications it is often the case that only estimates on the size of the transitive closure and on the number of nodes reachable from certain nodes are needed. We present an O(m) time randomized algorithm that estimates the number of nodes reachable from every node and the size of the transitive closure. We also obtain a O/spl tilde/(m) time algorithm for estimating sizes of neighborhoods in directed graphs with nonnegative weights, avoiding the O/spl tilde/(mn) time bound of explicitly computing these neighborhoods. Our size-estimation algorithms are much faster than performing the actual computations and improve significantly over previous estimation methods.