Christoph Tempich

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This paper describes the design and implementation of Bibster, a Peer-to-Peer system for exchanging bibliographic data among researchers. Bibster exploits ontologies in data-storage, query formulation, query-routing and answer presentation: When bibliographic entries are made available for use in Bibster, they are structured and classified according to two(More)
Ontology engineering processes in truly distributed settings like the Semantic Web or global peer-to-peer systems may not be adequately supported by conventional, centralized ontology engineering methodologies. In this paper, we present our work towards the DILIGENT methodology, which is intended to support domain experts in a distributed setting to(More)
A prerequisite to the success of the Semantic Web are shared ontologies which enable the seamless exchange of information between different parties. Engineering a shared ontology is a social process. Since its participants have slightly different views on the world, a harmonization effort requires discussing the resulting ontology. During the discussion,(More)
In peer-to-peer networks, finding the appropriate answer for an information request, such as the answer to a query for RDF(S) data, depends on selecting the right peer in the network. We hereinvestigate how social metaphors can be exploited effectively andefficiently to solve this task. To this end, we define a method for query routing, REMINDIN', that lets(More)
Peer selection for query routing is a core task in peer-to-peer networks. Unstructured peer-to-peer systems (like Gnutella) ignore this problem, leading to an abundance of network traffic. Structured peer-to-peer systems (like Chord) enforce a particular, global way of distributing data among the peers in order to solve this problem, but then encounter(More)
Case Study Purpose: The ontology engineering methodology DILIGENT is presented, a methodology focussing on the evolution of ontologies instead of the initial design, thus recognizing that knowledge is a tangible and moving target. Approach: First we describe the methodology as a whole, then detailing one of the five main steps of DILIGENT. The second part(More)
Peer-to-Peer systems are a new paradigm for information sharing and some systems have successfully been deployed. It has been argued that current Peer-to-Peer systems suffer from the lack of semantics. The SWAP project (Semantic Web and Peer-to-Peer) aims at overcoming this problem by combining the Peer-to-Peer paradigm with Semantic Web technologies. In(More)
Existing mature ontology engineering approaches are based on some basic assumptions that are often neglected in practice. Ontologies often need to be built in a decentralized way, ontologies must be given to a community in a way such that individuals have partial autonomy over them, ontologies have a life cycle that involves an iteration back and forth(More)
The theoretical results achieved in the ontology engineering field in the last fifteen years are of incontestable value for the prospected large scale take-up of semantic technologies. Their range of application in real-world projects is, however, so far comparatively limited, despite the growing number of ontologies online available. This restricted impact(More)
Benchmarks are one important aspect of performance evaluation. This paper concentrates on the development of a representative benchmark for Semantic Web-type ontologies. To this extent we perform a statistical analysis of available Semantic Web ontologies, in our case the DAML ontology library, and derive parameters that can be used for the generation of(More)