1039 search results - page 158 / 208 » Query reformulation with constraints |
171
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PODS
2012
ACM
13 years 8 months ago
2012
ACM
Over the past several decades, the study of conjunctive queries has occupied a central place in the theory and practice of database systems. In recent years, conjunctive queries h...
192
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CIKM
2009
Springer
16 years 1 days ago
2009
Springer
Background: Finding relevant articles from PubMed is challenging because it is hard to express the user’s specific intention in the given query interface, and a keyword query ty...
172
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STOC
2006
ACM
16 years 5 months ago
2006
ACM
The PCP theorem [3, 2] says that every language in NP has a witness format that can be checked probabilistically by reading only a constant number of bits from the proof. The cele...
161
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CSL
2009
Springer
15 years 9 months ago
2009
Springer
We introduce tree-width for first order formulae , fotw(). We show that computing fotw is fixed-parameter tractable with parameter fotw. Moreover, we show that on classes of formul...
156
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CSFW
2004
IEEE
15 years 9 months ago
2004
IEEE
We study the specification of access control policy in large-scale distributed systems. We present Cassandra, a language and system for expressing policy, and the results of a sub...