Results 11 - 20 of 1,218

Description Logics in Data Management

by Alexander Borgida , 1995
"... Description logics and reasoners, which are descendants of the kl-one language, have been studied in depth in Artificial Intelligence. After a brief introduction, we survey in this paper their application to the problems of information management, using the framework of an abstract information serve ..."
Abstract - Cited by 188 (13 self) - Add to MetaCart
Description logics and reasoners, which are descendants of the kl-one language, have been studied in depth in Artificial Intelligence. After a brief introduction, we survey in this paper their application to the problems of information management, using the framework of an abstract information server equipped with several operations -- each involving one or more languages. Specifically, we indicate how one can achieve enhanced access to data and knowledge by using descriptions in languages for schema design and integration, queries, answers, updates, rules, and constraints.
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Semantic and schematic similarities between database objects: A context-based approach

by Vipul Kashyap, Amit Sheth - VLDB Journal , 1996
"... Inamultidatabase system, schematic con icts between two objects are usually of interest only when the objects have some semantic similarity. We use the concept of semantic proximity, which is essentially an abstraction/mapping between the domains of the two objects associated with the context of com ..."
Abstract - Cited by 182 (16 self) - Add to MetaCart
Inamultidatabase system, schematic con icts between two objects are usually of interest only when the objects have some semantic similarity. We use the concept of semantic proximity, which is essentially an abstraction/mapping between the domains of the two objects associated with the context of comparison. An explicit though partial context representation is proposed and the speci city relationship between contexts is de ned. The contexts are organized as a meet semi-lattice and associated operations like the greatest lower bound (glb) are de ned. The context of comparison and the type of abstractions used to relate the two objects form the basis of a semantic taxonomy. Atthesemantic level, the intensional description of database objects provided by the context is expressed in a description logic language. Schema correspondences are used to store mappings from the semantic level to the data level and are associated with the respective contexts. Inferences about database content at the federation level are modeled as changes in the context and the associated schema correspondences. We try to reconcile the dual (schematic and semantic) perspecitves by: enumerating possible semantic similarities between objects having schema and data conicts, and modeling schema correspondences as the projection of semantic proximity wrt context. 1

Ontology-Driven Geographic Information Systems

by Frederico T. Fonseca, Max J. Egenhofer , 1999
"... This paper introduces a geographic information system architecture based on ontologies. Ontology plays a central role in the definition of all aspects and components of an information system in the so-called ontology-driven information systems. The system presented here uses a container of interoper ..."
Abstract - Cited by 175 (23 self) - Add to MetaCart
This paper introduces a geographic information system architecture based on ontologies. Ontology plays a central role in the definition of all aspects and components of an information system in the so-called ontology-driven information systems. The system presented here uses a container of interoperable geographic objects. The objects are extracted from multiple independent data sources and are derived from a strongly typed mapping of classes from multiple ontologies. This approach provides a great level of interoperability and allows partial integration of information when completeness is impossible.

Semantic E-Workflow Composition

by Jorge Cardoso, Amit Sheth - Journal of Intelligent Information Systems , 2003
"... Systems and infrastructures are currently being developed to support Web services. The main idea is to encapsulate an organization’s functionality within an appropriate interface and advertise it as Web services. While in some cases Web services may be utilized in an isolated form, it is normal to e ..."
Abstract - Cited by 171 (28 self) - Add to MetaCart
Systems and infrastructures are currently being developed to support Web services. The main idea is to encapsulate an organization’s functionality within an appropriate interface and advertise it as Web services. While in some cases Web services may be utilized in an isolated form, it is normal to expect Web services to be integrated as part of workflow processes. The composition of workflow processes that model e-service applications differs from the design of traditional workflows, in terms of the number of tasks (Web services) available to the composition process, in their heterogeneity, and in their autonomy. Therefore, two problems need to be solved: how to efficiently discover Web services – based on functional and operational requirements – and how to facilitate the interoperability of heterogeneous Web services. In this paper, we present a solution within the context of the emerging Semantic Web, that includes use of ontologies to overcome some of the problems. We start by illustrating the steps involved in the composition of a workflow. Two of these steps are the discovery of Web services and their posterior integration into a workflow. To assist designers with those two steps, we have devised an algorithm to simultaneously discover Web services and resolve heterogeneity among their interfaces and the workflow host. Finally, we describe a prototype that has been implemented to illustrate how discovery and interoperability functions are achieved.
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SEMINT: A tool for identifying attribute correspondences in heterogeneous databases using neural networks

by Wen-Syan Li, Chris Clifton - DATA & KNOWLEDGE ENGINEERING , 2000
"... ..."
Abstract - Cited by 166 (5 self) - Add to MetaCart
Abstract not found

Piazza: Data Management Infrastructure for Semantic Web

by Alon Halevy, Zachary Ives, Peter Mork, Igor Tatarinov , 2003
"... The Semantic Web envisions a World Wide Web in which data is described with rich semantics and applications can pose complex queries. To this point, researchers have defined new languages for specifying meanings for concepts and developed techniques for reasoning about them, using RDF as the data mo ..."
Abstract - Cited by 166 (12 self) - Add to MetaCart
The Semantic Web envisions a World Wide Web in which data is described with rich semantics and applications can pose complex queries. To this point, researchers have defined new languages for specifying meanings for concepts and developed techniques for reasoning about them, using RDF as the data model. To flourish, the Semantic Web needs to be able to accommodate the huge amounts of existing data and the applications operating on them. To achieve this, we are faced with two problems. First, most of the world's data is available not in RDF but in XML; XML and the applications consuming it rely not only on the domain structure of the data, but also on its document structure. Hence, to provide interoperability between such sources, we must map between both their domain structures and their document structures. Second, data management practitioners often prefer to exchange data through local point-to-point data translations, rather than mapping to common mediated schemas or ontologies.
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A graph-oriented model for articulation of ontology interdependencies

by Prasenjit Mitra, Gio Wiederhold, Martin L. Kersten - In Proceedings, 7th International Conference on Extending Database Technology , 2000
"... Abstract: Ontologies are knowledge structures to explicate the contents, essential properties, and relationships between terms in a knowledge source. Many sources are now accessible with associated ontologies. Most prior work on use of ontologies relies on the construction of a single global ontolog ..."
Abstract - Cited by 159 (4 self) - Add to MetaCart
Abstract: Ontologies are knowledge structures to explicate the contents, essential properties, and relationships between terms in a knowledge source. Many sources are now accessible with associated ontologies. Most prior work on use of ontologies relies on the construction of a single global ontology covering all sources. Such an approach is not scalable and maintainable especially when the sources change frequently. Wepropose a scalable and easily maintainable approach based on the interoperation of ontologies. To handle user queries crossing the boundaries of the underlying information systems, the interoperation between the ontologies should be precisely de ned. Our approach is to use rules that cross the semantic gap by creating an articulation or linkage between the systems. The rules are generated using a semi-automatic articulation tool with the help of a domain expert. To make the ontologies amenable for automatic composition based on the accumulated knowledge rules, we represent them using a graph-oriented model extended with a small algebraic operator set. ONION, a user-friendly toolkit, aids the experts in bridging the semantic gap in real-life settings. Our framework provides a sound foundation to simplify the work of do-This work was partially supported by a grant from the Air Force O ce of Scienti c Research (AFOSR).main experts, enables integration with public semantic dictionaries, like Wordnet, and will derive ODMG-compliant mediators automatically.
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Model Independent Assertions for Integration of Heterogeneous Schemas

by Stefano Spaccapietra, Christine Parent, Yann Dupont , 1991
"... Due to the proliferation of database applications, the integration of existing databases into a distributed or federated system is one of the major challenges in responding to enterprises' information requirements. Some proposed integration techniques aim at providing database administrators (D ..."
Abstract - Cited by 146 (8 self) - Add to MetaCart
Due to the proliferation of database applications, the integration of existing databases into a distributed or federated system is one of the major challenges in responding to enterprises' information requirements. Some proposed integration techniques aim at providing database administrators (DBAs) with a view definition language they can use to build the desired integrated schema. These techniques leave to the DBA the responsibility of appropriately restructuring schema elements from existing local schemas and of solving inter-schema conflicts. This paper investigates the assertion-based approach, in which the DB~s action is limited to pointing out corresponding elements in the schemas and to defining the nature of the correspondence in between. This methodology is capable of: en-suring better integration by taking into account additional semantic information (assertions about links); automatically solving structural conflicts; building the integrated schema without requiring conforming of initial schemas; applying inte-gration rules to a variety of data models; and performing view as well as database integration. This paper presents the basic ideas underlying our approach and focuses on resolution of structural conflicts.

Semantic integration research in the database community: A brief survey

by Anhai Doan, Alon Y. Halevy - AI Magazine , 2005
"... Semantic integration has been a long-standing challenge for the database community. It has received steady attention over the past two decades, and has now become a prominent area of database research. In this article, we first review database applications that require semantic integration, and disc ..."
Abstract - Cited by 145 (4 self) - Add to MetaCart
Semantic integration has been a long-standing challenge for the database community. It has received steady attention over the past two decades, and has now become a prominent area of database research. In this article, we first review database applications that require semantic integration, and discuss the difficulties underlying the integration process. We then describe recent progress and identify open research issues. We will focus in particular on schema matching, a topic that has received much attention in the database community, but will also discuss data matching (e.g., tuple deduplication), and open issues beyond the match discovery context (e.g., reasoning with matches, match verification and repair, and reconciling inconsistent data values). For previous surveys of database research on semantic integration, see (Rahm & Bernstein 2001;
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Composing Mappings among Data Sources

by Jayant Madhavan, Alon Y. Halevy - In VLDB , 2003
"... Semantic mappings between data sources play a key role in several data sharing architectures. Mappings provide the relationships between data stored in different sources, and therefore enable answering queries that require data from other nodes in a data sharing network. Composing mappings is one of ..."
Abstract - Cited by 140 (9 self) - Add to MetaCart
Semantic mappings between data sources play a key role in several data sharing architectures. Mappings provide the relationships between data stored in different sources, and therefore enable answering queries that require data from other nodes in a data sharing network. Composing mappings is one of the core problems that lies at the heart of several optimization methods in data sharing networks, such as caching frequently traversed paths and redundancy analysis.