- From: Luciano, Joanne S. <jluciano@mitre.org>
- Date: Mon, 1 Oct 2007 12:54:21 -0400
- To: "Michael Schneider" <schneid@fzi.de>, "Emanuele D'Arrigo" <manu3d@gmail.com>
- Cc: "Semantic Web Interest Group" <semantic-web@w3.org>, "public-owl-dev-request@w3.org" <public-owl-dev@w3.org>
Can anyone suggest a non-Jena / non-Java alternative? And for RDF (without OWL) also? Thanks, Joanne >-----Original Message----- >From: public-owl-dev-request@w3.org >[mailto:public-owl-dev-request@w3.org] On Behalf Of Michael Schneider >Sent: Wednesday, September 26, 2007 1:37 PM >To: Emanuele D'Arrigo >Cc: Semantic Web Interest Group; public-owl-dev-request@w3.org >Subject: RE: Is the ontology structure stored seamlessly with its data? > > >Hi, Emanuele! > >Emanuele D'Arrigo wrote at September 26, 2007: > >>Another thing that is not quite clear in my mind right now is this: >>are the sets of triplets describing the class and property hierarchies >>of an ontology normally stored seamlessly alongside the data that >>is classified and characterized by those classes and properties? > >With OWL, for which an RDF mapping exists, this is technically possible >without a problem. And when you, for instance, use JENA [1], a >well known >RDF framework for Java, you generally /work/ with ontology >based knowledge >bases in such a way (at least in principle). > >With JENA, you typically build a view to your knowledge base in the >following way: > > 1) Create a so called "Model", which is empty at the beginning > > 2) Read into this Model the RDF statements representing the >axioms of your >OWL ontology > > 3) Read into this Model the RDF statements of your knowledge base > >A "Model" in Jena represents an RDF graph, i.e. a set of RDF >triples. Now, >as long as you use a pure "Model", this only gives you a view to the >combined set of RDF triples, which come from both your OWL >ontology and your >knowledge base. But if you instead use an "OntModel" (which stands for >"Ontology Model"), you get an extended view to your RDF graph: >Suddenly, you >have additional API functionality to access all your OWL classes and >properties, and the (explicit) sub-relationships between them (and many >other ontology specific features). The magic behind this is that the >OntModel internally separates out all those triple subsets within the >combind RDF graph, which are RDF mappings for OWL axioms. > >So this is the situation (or at least a possible and perfectly working >situation), when you /work/ with knowledge data. This does >not, however, >mean that you should also /store/ ontological and assertional >data together >in the same RDF graph. I think, in most cases it will be a >better strategy >to have them separately stored. Then, you can easily reuse the >ontology for >different knowledge bases, and combine them /on the fly/, >whenever you want >to work with them. > >Cheers, >Michael > >[1] http://jena.sourceforge.net/ (JENA project page) > >-- >Dipl.-Inform. Michael Schneider >FZI Forschungszentrum Informatik Karlsruhe >Abtl. Information Process Engineering (IPE) >Tel : +49-721-9654-726 >Fax : +49-721-9654-727 >Email: Michael.Schneider@fzi.de >Web : http://www.fzi.de/ipe/eng/mitarbeiter.php?id=555 > >FZI Forschungszentrum Informatik an der Universität Karlsruhe >Haid-und-Neu-Str. 10-14, D-76131 Karlsruhe >Tel.: +49-721-9654-0, Fax: +49-721-9654-959 >Stiftung des bürgerlichen Rechts >Az: 14-0563.1 Regierungspräsidium Karlsruhe >Vorstand: Rüdiger Dillmann, Michael Flor, Jivka Ovtcharova, Rudi Studer >Vorsitzender des Kuratoriums: Ministerialdirigent Günther Leßnerkraus > >
Received on Monday, 1 October 2007 16:54:52 UTC