- From: Minsu Jang <minsu@etri.re.kr>
- Date: Thu, 20 Nov 2003 13:58:34 +0900
- To: "'Jim Hendler'" <hendler@cs.umd.edu>, <public-webont-comments@w3.org>
Hi, This is our experience of implementing Bossam rule engine and applying it for OWL inference. First, the overall story of implementation. The inference engine we use, Bossam, is a production rule engine we developed in this year. We tried to design Bossam so that it can be comfortably used for reasoning on the web. After finishing the first phase of Bossam development, we started to write inference rules for OWL. At first, we did not understand well the differences among OWL species, but now we've just begun to understand. We're reorganizing a rulebase for OWL. We're currently working on OWL DL inference. And here're some numbers: - 1 month for understanding ontology and OWL *in general*. We had no prior knowledge on description logics, then. But we knew about RDF, frames, FOL and AI in general. It was and still is difficult for us, non-experts in logics and computational theory, to catch exactly what the differences and meanings imposed on different OWL species are. OWL AS&S is a notorious document among developers in here. - 5 months for implementing the first (quasi-)stable version of Bossam - 1 month for designing Buchingae, a rule language for Bossam, and implementing a parser for it. We used ANTLR for writing syntax rules and generating a parser. - 1/4 month for implementing an OWL importing feature for Bossam. We used Jena2 to produce RDF triples from OWL documents. The triples are transformed into a series of facts, which are finally loaded into Bossam's working memory. This was quite straight and simple. - 1/2 month for writing inference rules for OWL. We began from OWL test cases one by one and wrote rules for each test case. We soon realized that it was not a proper process of working out inference rules for OWL. - 1/4 month for writing inference rules for OWL DL. Still far from complete, and there're still many things to be learned. Currently, Bossam has passed 50 tests out of 88 approved positive entailment tests. There are 15 facts and 55 rules defined in the rulebase for OWL DL inference. It took about 6 minutes to load W3C's wine ontology and derive all the facts derivable by the rulebase. Hope it helps. Best, Minsu -------------------------------------------------- Minsu Jang Senior Member of Engineering Staff Business Knowledge Research Team Electronics and Telecommunications Research Institute Phone: +82-42-860-1250 Fax: +82-42-860-6790
Received on Wednesday, 19 November 2003 23:58:47 UTC