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26
Content Metrics for Products and Services Categorization Standards
- PROC. OF THE IEEE INTERNATIONAL CONFERENCE ON E-TECHNOLOGY, E-COMMERCE AND E-SERVICE (EEE-05), HONG KONG, 2005
, 2005
"... Products and services categorization standards, such as ..."
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Products and services categorization standards, such as
The ICS-FORTH Semantic Web Integration Middleware (SWIM)
- SWIM), IEEE Data Engineering Bulletine
, 2003
"... This paper presents the fundamental ideas for devising a comprehensive framework that allows user communities to 1. specify XML RDF and RDB RDF mappings; 2. verify that these mappings conform to the semantics of the employed SW ontologies; 3. compose RQL queries with these mappings and prod ..."
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Cited by 6 (0 self)
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This paper presents the fundamental ideas for devising a comprehensive framework that allows user communities to 1. specify XML RDF and RDB RDF mappings; 2. verify that these mappings conform to the semantics of the employed SW ontologies; 3. compose RQL queries with these mappings and produce XML or RDB queries; 4. specify further levels of abstraction as RDF RDF views; 5. compose RQL queries with such views; 6. perform query optimizations
Petrakis: Semantic Similarity Measures: A Comparison StudyTechnical (Intelligent systems laboratory
, 2005
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Enhancing Semantic Web Data Access
, 2006
"... The Semantic Web was invented by Tim Berners-Lee in 1998 as a web of data for machine consumption. Its applicability in supporting real world applications on the World Wide Web, however, remains unclear to this day because most existing works treat the Semantic Web as one universal RDF graph and ign ..."
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Cited by 4 (3 self)
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The Semantic Web was invented by Tim Berners-Lee in 1998 as a web of data for machine consumption. Its applicability in supporting real world applications on the World Wide Web, however, remains unclear to this day because most existing works treat the Semantic Web as one universal RDF graph and ignore the Web aspect. In fact, the Semantic Web is distributed on the Web as a web of belief: each piece of Semantic Web data is independently published on the Web as a certain agent’s belief instead of the universal truth. Therefore, we enhance the current conceptual model of the Semantic Web to characterize both the content and the context of Semantic Web data. A significant sample dataset is harvested to demonstrate the non-trivial presence and the global properties of the Semantic Web on the Web. Based on the enhanced conceptual model, we introduce a novel search and navigation model for the unique behaviors in Web-scale Semantic Web data access, and develop an enabling tool – the Swoogle Semantic Web search engine. To evaluate the data quality of Semantic Web data, we also (i) develop an explainable ranking schema that orders the popularity of Semantic Web documents and terms, and (ii) introduce a new level of granularity of Semantic Web data – RDF molecule that supports lossless RDF graph decomposition and effective provenance tracking. This dissertation systematically investigates the Web aspect of the Semantic Web. Its primary contribu-tions are the enhanced conceptual model of the Semantic Web, the novel Semantic Web search and navigation model, and the Swoogle Semantic Web search engine.
Inheritance in Rule-Based Frame Systems: Semantics and Inference
- Journal on Data Semantics VII
"... Knowledge representation languages that combine rules with object-oriented features akin to frame systems have recently attracted a lot of research interest, and F-logic is widely seen as a basis to achieve this integration. In this paper we extend the original F-logic formalism with an array of sa ..."
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Knowledge representation languages that combine rules with object-oriented features akin to frame systems have recently attracted a lot of research interest, and F-logic is widely seen as a basis to achieve this integration. In this paper we extend the original F-logic formalism with an array of salient features that are essential for representing and reasoning with commonsense knowledge. In particular, we extend the syntax and semantics of F-logic to incorporate nonmonotonic multiple inheritance of class and instance methods in the presentence of class hierarchies defined via rules. The new semantics is completely model-theoretic and is free of the defects that caused the original F-logic to produce unintuitive results due to the unusual interaction between default inheritance and inference via rules. Moreover, we provide a computational framework for the new F-logic semantics which can be implemented by inference engines using either forward or backward chaining mechanisms.
Efficient Query Routing in RDF/S Schema-based P2P Systems
- In Fourth Hellenic Data Management Symposium (HDMS’05
, 2005
"... P2P computing gains increasing attention lately, since it provides the means for realizing computing systems that scale to very large numbers of participating peers, while ensuring high autonomy and fault-tolerance. However, existing P2P systems o#er poor data management facilities, limited to IR-st ..."
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P2P computing gains increasing attention lately, since it provides the means for realizing computing systems that scale to very large numbers of participating peers, while ensuring high autonomy and fault-tolerance. However, existing P2P systems o#er poor data management facilities, limited to IR-style keyword search using eventually a fixed set of document attributes. Schema-based P2P systems have been proposed to support richer facilities in exchanging, querying and integrating structured and semi-structured data hosted by peers. In this paper, we address routing issues for expressive queries in schema-based P2P systems, where peers advertise their local bases using fragments of a community RDF/S schema (i.e., views). We then introduce an original encoding of RDF/S schema fragments, allowing to e#ciently check whether a peer view is subsumed by a query. We rely on this encoding to design an RDF/S view lookup service featuring a centralized and distributed execution over a DHT-based P2P system. We finally evaluate experimentally the proposed framework to demonstrate its scalability for large P2P networks and arbitrary RDF/S schema fragments, as well as, to estimate the number of routing hops required by the two versions of our lookup service.
G.: The ICS-FORTH SWIM: A Powerful Semantic Web Integration Middleware. Submitted for publication (2003
"... Abstract. Semantic Web (SW) technology aims to facilitate the integration of legacy data sources spread worldwide. Despite the plethora of SW languages (e.g., RDF/S, DAML+OIL, OWL) recently proposed for capturing data semantics, the vast majority of legacy sources still rely on relational databases ..."
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Abstract. Semantic Web (SW) technology aims to facilitate the integration of legacy data sources spread worldwide. Despite the plethora of SW languages (e.g., RDF/S, DAML+OIL, OWL) recently proposed for capturing data semantics, the vast majority of legacy sources still rely on relational databases (RDB) published on the Web or corporate intranets as virtual XML. In this paper, we advocate a Datalog framework for mediating high-level queries to relational and/or XML sources using community ontologies expressed in a SW language such as RDF/S. We describe the architecture and the reasoning services of our SW integration middleware, called SWIM, and we present the main design choices and techniques for supporting powerful mappings between di erent data models, as well as, reformulation and optimization of queries expressed against mediation schemas and views. 1
Ontology-based Infrastructure for Intelligent Applications
, 2004
"... Ontologies currently are a hot topic in the areas of knowledge management and enterprise application integration. In this thesis, we investigate how ontologies can also be used as an infrastructure for developing applications that intelligently support a user with various tasks. Based on recent deve ..."
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Ontologies currently are a hot topic in the areas of knowledge management and enterprise application integration. In this thesis, we investigate how ontologies can also be used as an infrastructure for developing applications that intelligently support a user with various tasks. Based on recent developments in the area of the Semantic Web, we provide three major contributions. We introduce inference engines, which allow the execution of business logic that is speci ed in a declarative way, while putting strong emphasis on scalability and ease of use. Secondly, we suggest various solutions for interfacing applications that are developed under this new paradigm with existing IT infrastructure. This includes the rst running solution, to our knowledge, for combining the emerging areas of the Semantic Web and Web Services. Finally, we introduce a set of intelligent applications, which is built on top of ontologies and Semantic Web standards, providing a proof of concept that the engineering eort can largely be based on standard components.
Indexing views to route queries in a PDMS
, 2008
"... Indexing views to route queries in a PDMS ..."
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Distributed and Parallel Databases manuscript No. (will be inserted by the editor) Indexing Views to Route Queries in a PDMS
"... Abstract P2P computing gains increasing attention lately, since it pro-vides the means for realizing computing systems that scale to very large numbers of participating peers, while ensuring high autonomy and fault-tolerance. Peer Data Management Systems (PDMS) have been proposed to support sophisti ..."
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Abstract P2P computing gains increasing attention lately, since it pro-vides the means for realizing computing systems that scale to very large numbers of participating peers, while ensuring high autonomy and fault-tolerance. Peer Data Management Systems (PDMS) have been proposed to support sophisticated facilities in exchanging, querying and integrating (semi-) structured data hosted by peers. In this paper, we are interested in routing graph queries in a very large PDMS, where peers advertise their local bases using fragments of community RDF/S schemas (i.e., views). We introduce an original encoding for these fragments, in order to efficiently check whether a peer view is subsumed by a query. We rely on this en-coding to design an RDF/S view lookup service featuring a statefull and a 2 Lefteris Sidirourgos et al. stateless execution over a DHT-based P2P infrastructure. We finally evalu-ate experimentally our system to demonstrate its scalability for very large P2P networks and arbitrary RDF/S schema fragments, and to estimate the number of routing hops required by the two versions of our lookup service. 1
