Showing papers by "Christian Bizer published in 2004"

D2R Server - Publishing Relational Databases on the Semantic Web

Abstract: D2R Server is a tool for publishing the content of relational databases on the Semantic Web. Database content is mapped to RDF by a declarative mapping which specifies how resources are identified and how property values are generated from database content. Based on this mapping, D2R Server allows Web agents to retrieve RDF and XHTML representations of resources and to query non-RDF databases using the SPARQL query language over the SPARQL protocol. The generated representations are richly interlinked on RDF and XHTML level in order to enable browsers and crawlers to navigate database content.

Using context- and content-based trust policies on the semantic web

Abstract: The current discussion about a future Semantic Web trust architecture is focused on reputational trust mechanisms based on explicit trust ratings. What is often overlooked is the fact that, besides of ratings, huge parts of the application-specific data published on the Semantic Web are also trust relevant and therefore can be used for flexible, fine-grained trust evaluations. In this poster we propose the usage of context- and content-based trust mechanisms and outline a trust architecture which allows the formulation of subjective and task-specific trust policies as a combination of reputation-, context- and content-based trust mechanisms.

Semantic web publishing using named graphs

Abstract: The Semantic Web consists of many RDF graphs nameable by URIs. This paper extends the syntax and semantics of RDF to cover such Named Graphs. This enables RDF statements that describe graphs, which is beneficial in many Semantic Web application areas. In this paper, we explore the application area of Semantic Web publishing: Named Graphs allow publishers to communicate assertional intent, and to sign their graphs; information consumers can evaluate specific graphs using task-specific trust policies, and act on information from those Named Graphs that they accept. Graphs are trusted depending on: their content; information about the graph; and the task the user is performing. The extension of RDF to Named Graphs provides a formally defined framework to be a foundation for the Semantic Web trust layer.

Trustable B2C markets on the Semantic Web

Abstract: Semantic Web technologies will deeply influence the further development of the Internet Economy. A major challenge is, however, to find a practical solution for trust problems arising from their deployment in real-world scenarios. In this paper we develop a concrete application scenario based on Semantic Web technologies for the domain of business to consumer electronic commerce to illustrate these problems. A possible underlying technical architecture can well be realized building on todays standards. The resulting scenario is used for a preliminary analysis of the potential impacts of Semantic Web applications on market participants. Specific to the scenario we describe trust requirements and outline a Semantic Web trust architecture which fulfils them. The architecture focuses on the allowing subjective and task-specific trust policies as a combination of reputation-, contextand content-based trust mechanisms.