- From: Wolfgang Nejdl <nejdl@kbs.uni-hannover.de>
- Date: Tue, 21 Aug 2001 00:22:52 +0200
- To: www-rdf-logic@w3.org
Somehow I did not manage to post this article successfully to rdf-logic from my Stanford account last week. Maybe it works directly from my Hannover account ... I would love to get feedback from the rdf-logic discussion group. ================================================================ To: www-rdf-logic@w3.org cc: Wolfgang Nejdl <nejdl@stanford.edu>, "Manfred A. Jeusfeld" <Manfred.Jeusfeld@kub.nl>, Martin Wolpers <wolpers@kbs.uni-hannover.de>, Hadhami Dhraief <dhraief@kbs.uni-hannover.de> Reply-To: nejdl@stanford.edu Subject: Metamodeling and Reification Mime-Version: 1.0 (generated by tm-edit 1.5) Date: Tue, 14 Aug 2001 23:53:17 -0700 From: Wolfgang Nejdl <nejdl@liszt-n.kbs.uni-hannover.de> As this list has recently discussed several formalizations of RDF(S)-like languages, as well as the use of RDF(S) as base language for defining other languages, I am posting a reference to a recent report (finished one month ago) http://www.kbs.uni-hannover.de/Arbeiten/Publikationen/2001/kcap01-workshop.pdf which might be useful in this context. In this report we describe the formalization of an RDF(S) variant called O-Telos-RDF, which provides enhanced functionalities for meta-modeling and reified statements, both aspects relevant in using RDF(S) as the base semantic language of the Web. The formalization is based very closely on the formalization of the modeling language O-Telos, which is based on a semantic network model similar to RDF(S), and which has been used as a (meta) modeling language in various application areas during the last 10 years. Axioms and constraints of O-Telos-RDF are clearly defined and contrasted with both the RDF(S) and the original O-Telos language. This exact formalization will hopefully contribute to an understanding of both O-Telos-RDF and (in this context) the current RDF(S) formalization and its constraints. Our main goal in describing O-Telos-RDF was to show how expressive a resource description framework based on simple semantic networks (like RDF graphs) and a basic formalization of type and subclass relations can be, therefore exploiting and advancing features already present in the current RDF(S) formalization, without introducing additional features not present in the current RDF(S) framework. Compared with RDF(S), O-Telos-RDF shows its advantages in allowing easier reification of statements, and in metamodelling applications, where more than the three abstraction hierarchies provided in RDF(S) are needed. Furthermore, the class centric approach to property definition allows the definition of properties with the same name for different domains, which have different ranges (not possible in RDF(S)). These properties seem to make O-Telos-RDF more similar to DAML+OIL than RDF(S) is (in the sense that DAML+OIL is more easily/naturally represented in O-Telos-RDF than in RDF(S)), but our report does not yet include a comparison of O-Telos-RDF with DAML+OIL concepts. Further online references: Short description of O-Telos: http://www-i5.informatik.rwth-aachen.de/CBdoc/O-Telos.html Selected O-Telos-Papers: http://www-i5.informatik.rwth-aachen.de/CBdoc/cblit.html Wolfgang Nejdl -- Prof. Dr. Wolfgang Nejdl tel. +49 511 762-19710 Institut für Technische Informatik fax. +49 511 762-19712 Rechnergestützte Wissensverarbeitung http://www.kbs.uni-hannover.de/ Educational Technology Lab http://www.etl.uni-hannover.de/ Learning Lab Lower Saxony http://www.learninglab.de/ Universität Hannover, Appelstraße 4, 30167 Hannover, Deutschland
Received on Monday, 20 August 2001 18:23:17 UTC