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Integration of Heterogeneous Databases Without Common Domains Using Queries Based on Textual Similarity
, 1998
"... Most databases contain "name constants" like course numbers, personal names, and place names that correspond to entities in the real world. Previous work in integration of heterogeneous databases has assumed that local name constants can be mapped into an appropriate global domain by norma ..."
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Cited by 246 (13 self)
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Most databases contain "name constants" like course numbers, personal names, and place names that correspond to entities in the real world. Previous work in integration of heterogeneous databases has assumed that local name constants can be mapped into an appropriate global domain by normalization. However, in many cases, this assumption does not hold; determining if two name constants should be considered identical can require detailed knowledge of the world, the purpose of the user's query, or both. In this paper, we reject the assumption that global domains can be easily constructed, and assume instead that the names are given in natural language text. We then propose a logic called WHIRL which reasons explicitly about the similarity of local names, as measured using the vectorspace model commonly adopted in statistical information retrieval. We describe an efficient implementation of WHIRL and evaluate it experimentally on data extracted from the World Wide Web. We show that WHIR...
Logic Programming and Knowledge Representation
 Journal of Logic Programming
, 1994
"... In this paper, we review recent work aimed at the application of declarative logic programming to knowledge representation in artificial intelligence. We consider exten sions of the language of definite logic programs by classical (strong) negation, disjunc tion, and some modal operators and sh ..."
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Cited by 242 (20 self)
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In this paper, we review recent work aimed at the application of declarative logic programming to knowledge representation in artificial intelligence. We consider exten sions of the language of definite logic programs by classical (strong) negation, disjunc tion, and some modal operators and show how each of the added features extends the representational power of the language.
Answering queries using templates with binding patterns
 In Proc. of the 14th ACM SIGACT SIGMOD SIGART Symp. on Principles of Database Systems (PODSâ€™95
, 1995
"... When integrating heterogeneous information resources, it is often the case that the source is rather limited in the kinds of queries it can answer. If a query is asked of the entire system, we have a new kind of optimization problem, in which we must try to express the given query in terms of the l ..."
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Cited by 216 (14 self)
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When integrating heterogeneous information resources, it is often the case that the source is rather limited in the kinds of queries it can answer. If a query is asked of the entire system, we have a new kind of optimization problem, in which we must try to express the given query in terms of the limited query templates that this source can answer. For the case of conjunctive queries, we show how to decide with a nondeterministic polynomialtime algorithm whether the given query can be answered. We then extend our results to allow arithmetic comparisons in the given query and in the templates.
What you always wanted to know about Datalog (and never dared to ask)
 IEEE TRANSACTIONS KNOWLEDGE AND DATA ENGINEERING
, 1989
"... Datalog is a database query language based on the logic programming paradigm; it has been designed and intensively studied over the last five years. We present the syntax and semantics of Datalog and its use for querying a relational database. Then, we classify optimization methods for achieving eff ..."
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Cited by 196 (3 self)
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Datalog is a database query language based on the logic programming paradigm; it has been designed and intensively studied over the last five years. We present the syntax and semantics of Datalog and its use for querying a relational database. Then, we classify optimization methods for achieving efficient evaluations of Datalog queries, and present the most relevant methods. Finally, we discuss various exhancements of Datalog, currently under study, and indicate what is still needed in order to extend Datalogâ€™s applicability to the solution of reallife problems. The aim of this paper is to provide a survey of research performed on Datalog, also addressed to those members of the database community who are not too familiar with logic programming concepts.
GraphLog: a Visual Formalism for Real Life Recursion
 In Proceedings of the Ninth ACM SIGACTSIGMOD Symposium on Principles of Database Systems
, 1990
"... We present a query language called GraphLog, based on a graph representation of both data and queries. Queries are graph patterns. Edges in queries represent edges or paths in the database. Regular expressions are used to qualify these paths. We characterize the expressive power of the language a ..."
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Cited by 201 (18 self)
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We present a query language called GraphLog, based on a graph representation of both data and queries. Queries are graph patterns. Edges in queries represent edges or paths in the database. Regular expressions are used to qualify these paths. We characterize the expressive power of the language and show that it is equivalent to stratified linear Datalog, first order logic with transitive closure, and nondeterministic logarithmic space (assuming ordering on the domain). The fact that the latter three classes coincide was not previously known. We show how GraphLog can be extended to incorporate aggregates and path summarization, and describe briefly our current prototype implementation. 1 Introduction The literature on theoretical and computational aspects of deductive databases, and the additional power they provide in defining and querying data, has grown rapidly in recent years. Much less work has gone into the design of languages and interfaces that make this additional pow...
Provenance semirings
 PODS'07
, 2007
"... We show that relational algebra calculations for incomplete databases, probabilistic databases, bag semantics and whyprovenance are particular cases of the same general algorithms involving semirings. This further suggests a comprehensive provenance representation that uses semirings of polynomials. ..."
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Cited by 197 (30 self)
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We show that relational algebra calculations for incomplete databases, probabilistic databases, bag semantics and whyprovenance are particular cases of the same general algorithms involving semirings. This further suggests a comprehensive provenance representation that uses semirings of polynomials. We extend these considerations to datalog and semirings of formal power series. We give algorithms for datalog provenance calculation as well as datalog evaluation for incomplete and probabilistic databases. Finally, we show that for some semirings containment of conjunctive queries is the same as for standard set semantics.
An Optimal Predicate Locking Scheduler
"... The paper presents a predicate locking scheduler that maximizes concurrency by locking as many of the database entities as possible without compromising the correctness of execution of the database transactions. The scheduling strategy that guarantees the maximal concurrency is first identified, the ..."
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The paper presents a predicate locking scheduler that maximizes concurrency by locking as many of the database entities as possible without compromising the correctness of execution of the database transactions. The scheduling strategy that guarantees the maximal concurrency is first identified
Pose estimation from corresponding point data
 IEEE Transactions on Systems, Man and Cybernetics
, 1989
"... AbstracrSolutions for four different pose estimation problems are presented. Closed form leastsquares solutions are given to the over constrained ZDZD and 3D3D pose estimation problems. A globally convergent iterative technique is given for the 2D perspective projection3D pose estimation ..."
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Cited by 198 (2 self)
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AbstracrSolutions for four different pose estimation problems are presented. Closed form leastsquares solutions are given to the over constrained ZDZD and 3D3D pose estimation problems. A globally convergent iterative technique is given for the 2D perspective projection3D pose estimation problem. A simplified linear solution and a robust solution to the 2D perspective projectionZD perspective projection pose estimation problem are also given. Simulation experiments consisting of millions of hia ls having varying numbers of pairs of corresponding points, varying signal to noise ratio (SNR) with either Gaussian or uniform noise provide data suggesting that accurate inference of rotation and translation with noisy data may require corresponding point data sets having hundreds of corresponding point pairs when the SNR is less than 40 dB. The experiment results also show that robust technique can suppress the effect of blunder data that come from outliers or mismatched points. I.
Concurrency control in advanced database applications
 ACM Computing Surveys
, 1991
"... Concurrency control has been thoroughly studied in the context of traditional database applications such as banking and airline reservations systems. There are relatively few studies, however, that address the concurrency control issues of advanced database applications such as CAD/CAM and software ..."
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Cited by 180 (15 self)
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Concurrency control has been thoroughly studied in the context of traditional database applications such as banking and airline reservations systems. There are relatively few studies, however, that address the concurrency control issues of advanced database applications such as CAD/CAM and software development environments. The
Results 11  20
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1,744