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SPARQL Beyond Subgraph Matching

by Birte Glimm, Markus Krötzsch
"... Abstract. We extend the Semantic Web query language SPARQL by defining the semantics of SPARQL queries under the entailment regimes of RDF, RDFS, and OWL. The proposed extensions are part of the SPARQL 1.1 Entailment Regimes working draft which is currently being developed as part of the W3C standar ..."
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Abstract. We extend the Semantic Web query language SPARQL by defining the semantics of SPARQL queries under the entailment regimes of RDF, RDFS, and OWL. The proposed extensions are part of the SPARQL 1.1 Entailment Regimes working draft which is currently being developed as part of the W3C

gStore: Answering SPARQL Queries via Subgraph Matching

by Lei Zou, Jinghui Mo, Lei Chen, M. Tamer Özsu, Dongyan Zhao - , 2011
"... Due to the increasing use of RDF data, efficient processing of SPA-RQL queries over RDF datasets has become an important issue. However, existing solutions suffer from two limitations: 1) they cannot answer SPARQL queries with wildcards in a scalable manner; and 2) they cannot handle frequent update ..."
Abstract - Cited by 25 (3 self) - Add to MetaCart
. A SPARQL query is then converted into a corresponding subgraph matching query. In order to speed up query processing, we develop a novel index, together with some effective pruning rules and efficient search algorithms. Our method can answer exact SPARQL queries and queries with wildcards in a

Optimizing SPARQL Query Answering over OWL Ontologies

by Ilianna Kollia, Birte Glimm
"... The SPARQL query language is currently being extended by the World Wide Web Consortium (W3C) with so-called entailment regimes. An entailment regime defines how queries are evaluated under more expressive semantics than SPARQL’s standard simple entailment, which is based on subgraph matching. The qu ..."
Abstract - Cited by 13 (4 self) - Add to MetaCart
The SPARQL query language is currently being extended by the World Wide Web Consortium (W3C) with so-called entailment regimes. An entailment regime defines how queries are evaluated under more expressive semantics than SPARQL’s standard simple entailment, which is based on subgraph matching

Implementing Iterative Algorithms with SPARQL

by Robert W. Techentin, Barry K. Gilbert, Adam Lugowski Kevin, Deweese John Gilbert, Eric Dull, Mike Hinchey, Steven P. Reinhardt
"... The SPARQL declarative query language includes innovative capabilities to match subgraph patterns within a semantic graph database, providing a powerful base upon which to implement complex graph algorithms for very large data. Iterative algorithms are useful in a wide variety of domains, in particu ..."
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The SPARQL declarative query language includes innovative capabilities to match subgraph patterns within a semantic graph database, providing a powerful base upon which to implement complex graph algorithms for very large data. Iterative algorithms are useful in a wide variety of domains

Index Support for SPARQL

by Ralf Heese, Ulf Leser, Bastian Quilitz, Christian Rothe
"... Abstract. The Resource Description Framework (RDF) is the fundamental data model underlying the Semantic Web. Recently, SPARQL has been proposed as W3C standard for querying RDF repositories. As RDF is a graph-based data model, the core problem of evaluating SPARQL queries is matching query graph pa ..."
Abstract - Cited by 3 (1 self) - Add to MetaCart
Abstract. The Resource Description Framework (RDF) is the fundamental data model underlying the Semantic Web. Recently, SPARQL has been proposed as W3C standard for querying RDF repositories. As RDF is a graph-based data model, the core problem of evaluating SPARQL queries is matching query graph

The Complexity of Finding Subgraphs Whose Matching Number Equals the Vertex Cover Number

by Sounaka Mishra, Venkatesh Raman, Saket Saurabh, Somnath Sikdar, C. R. Subramanian - IN PROCEEDINGS OF THE 18TH INTERNATIONAL SYMPOSIUM ON ALGORITHMS AND COMPUTATION (ISAAC 2007), SPRINGER LNCS , 2007
"... The class of graphs where the size of a minimum vertex cover equals that of a maximum matching is known as König-Egerváry graphs. König-Egerváry graphs have been studied extensively from a graph theoretic point of view. In this paper, we introduce and study the algorithmic complexity of finding ..."
Abstract - Cited by 7 (3 self) - Add to MetaCart
The class of graphs where the size of a minimum vertex cover equals that of a maximum matching is known as König-Egerváry graphs. König-Egerváry graphs have been studied extensively from a graph theoretic point of view. In this paper, we introduce and study the algorithmic complexity

gStore: A Graph-based SPARQL Query Engine

by Lei Zou, M. Tamer Özsu , Lei Chen , Xuchuan Shen, Ruizhe Huang, Dongyan Zhao
"... We address efficient processing of SPARQL queries over RDF datasets. The proposed techniques, incorporated into the gStore system, handle, in a uniform and scalable manner, SPARQL queries with wildcards and aggregate operators over dynamic RDF datasets. Our approach is graph-based. We store RDF dat ..."
Abstract - Cited by 4 (3 self) - Add to MetaCart
data as a large graph, and also represent a SPARQL query as a query graph. Thus the query answering problem is converted into a subgraph matching problem. To achieve efficient and scalable query processing, we develop an index, together with effective pruning rules and efficient search algorithms. We

The Complexity of König Subgraph Problems and Above-Guarantee Vertex Cover

by Sounaka Mishra, Venkatesh Raman, Saket Saurabh, Somnath Sikdar, C. R. Subramanian
"... A graph is König-Egerváry if the size of a minimum vertex cover equals that of a maximum matching in the graph. These graphs have been studied extensively from a graph-theoretic point of view. In this paper, we introduce and study the algorithmic complexity of finding König-Egerváry subgraphs of a g ..."
Abstract - Cited by 6 (2 self) - Add to MetaCart
A graph is König-Egerváry if the size of a minimum vertex cover equals that of a maximum matching in the graph. These graphs have been studied extensively from a graph-theoretic point of view. In this paper, we introduce and study the algorithmic complexity of finding König-Egerváry subgraphs of a

Detecting High Log-Densities – an O(n 1/4) Approximation for Densest k-Subgraph

by Aditya Bhaskara, Moses Charikar, Eden Chlamtac, Uriel Feige, Aravindan Vijayaraghavan
"... In the Densest k-Subgraph problem, given a graph G and a parameter k, one needs to find a subgraph of G induced on k vertices that contains the largest number of edges. There is a significant gap between the best known upper and lower bounds for this problem. It is NP-hard, and does not have a PTAS ..."
Abstract - Cited by 23 (1 self) - Add to MetaCart
random graphs with planted dense subgraphs – the approximation ratio we achieve for the general case matches the “distinguishing ratio ” we obtain for this planted problem. Achieving a distinguishing ratio of o(n1/4) for the planted problem (in polynomial time) is beyond the reach of our current

Unifying Graph Matching Problems with a Practical Solution

by Chao-wen Kevin Chen, David Y. Y. Yun - In Proc. of International Conference on Systems, Signals, Control, Computers , 1998
"... Recent advances in computer vision, information retrieval, and molecular biology amply demonstrate the value and importance of graph matching. However, graph matching algorithms developed to date are either application domainspecific or severely limited by the problem size. This paper presents a uni ..."
Abstract - Cited by 9 (0 self) - Add to MetaCart
unified solution for the broad range of major graph matching problems. Particularly, the new algorithm goes beyond matching given pattern graphs and effectively tackles two very difficult graph matching problems -- Maximal Common Subgraph and Maximal Overlap Sets. By mathematical proofs, these graph
Results 1 - 10 of 28