- From: Uschold, Michael F <michael.f.uschold@boeing.com>
- Date: Fri, 30 Apr 2004 15:33:47 -0700
- To: "Alan Rector" <rector@cs.man.ac.uk>
- Cc: <public-swbp-wg@w3.org>
Deborah may know for sure, but I think that the Ontolingua version of ther Gruber physical dimensions and units of measure ontology already has been translated to DAML+OIL and thus should be an easy matter to translate into OWL. It is another matter to look at the 'mess' the translators may have made :-). It might need a re-think as to how best it might be done in OWL. Mike -----Original Message----- From: Alan Rector [mailto:rector@cs.man.ac.uk] Sent: Friday, April 30, 2004 8:00 AM To: Uschold, Michael F Subject: Re: [OEP] a Quantity pattern? [was: Re: [UNITS] FAQ : Constraints on data values range] Mike I agree that Gruber's ontology is the place to start. A useful task would be to render it into OWL in a way most could agree on and post it. I'm not volunteering for that, although I'd happily comment. The sort of compromise you suggest seems sane to me and just in need of a tidy up. Regards Alan "Uschold, Michael F" wrote: > In cases where units and dimensions are important, then this may be a good guideline to work with. In most other cases, it may be extra baggage. I worked with Gruber's physical quantities ontology and on the whole thought it to be very high quality, well thought out and w/ few if any errors. > > Mike > > -----Original Message----- > From: public-swbp-wg-request@w3.org [mailto:public-swbp-wg-request@w3.org] On Behalf Of Guus Schreiber > Sent: Wednesday, April 14, 2004 7:38 AM > To: Bernard Vatant > Cc: SWBPD > Subject: [OEP] a Quantity pattern? [was: Re: [UNITS] FAQ : Constraints on data values range] > > Bernard Vatant wrote: > > > > I have not noticed any activity under [UNITS] so far ... this is a first bait :)) > > > > A FAQ in Protégé-OWL list, I'll give here the latest variant sent yesterday (summed up) > > > > "I have defined a class 'Wheel' > > and a DatatypeProperty 'diameterValue' > > on Domain 'Wheel' > > and Range 'Integer' > > Is this an opportunity for a modelling pattern? > Guideline: for numeric values, always use the "quantity" pattern > [Fowler, Gruber] > > For example (in a sloppy fashion, other have done this better) > ObjectProperty(diameterValue > domain(Wheel) range(LengthQuantity)) > Class(Quantity) > DatatypeProperty(value > domain(Quantity) > range(xsd:decimal)) > DatatypeProperty(unit > domain(Quantity) range(Unit)) > Class(LenthQuantity > subClassOf(Quantity) > Retriction(unit, allValuesFrom(LengthQuantity)) > Individual(myWheel > type(Wheel) diameterValue(type(LengthQuantity) value(15) unit(cm))) > [the middle part is general and could come out of some units-and-dimensions ontology] > Guus > > > > I want to create a class 'BigWheel' with a restriction on the property > > 'diameterValue', for instance 'diameterValue => 10'. > > > > How do I do that in OWL?" > > > > I had answered that basically you can't express that kind of 'quantitative restriction' in > > OWL, although there are workarounds, like using a 'minDiameterValue' property and so on. > > > > I guess every other user wanting to include units in one's ontology will hit that kind of > > wall. > > > > It figures we should come out with clear explanations why OWL does not support > > quantitative restrictions on DatatypeProperty with numerical Range, and more generally > > restrictions linked to the very nature of data themselves, like defining the class > > 'WellDescribedThing' by restriction on a 'description' value to 'over 1000 words'. > > > > [Seems to me that there are many ways to work around declaration of those kinds of > > restrictions, but that OWL internally makes no provision to check their consistency, but > > can be used to pass them as black boxes to external applications that can make sense of > > them. IOW, I can declare an instance of 'BigWheel' with 'diameterValue' set to 9.7, no > > inconsistency will be detected by pure logical tools with 'minDiameterValue = 10', but > > external applications able to deal with quantities will make sense of it.] > > > > Bernard Vatant > > Senior Consultant > > Knowledge Engineering > > Mondeca - www.mondeca.com > > bernard.vatant@mondeca.com > > > > > > > > -- > Free University Amsterdam, Computer Science > De Boelelaan 1081a, 1081 HV Amsterdam, The Netherlands > Tel: +31 20 444 7739/7718 > E-mail: schreiber@cs.vu.nl > Home page: http://www.cs.vu.nl/~guus/ -- Alan L Rector Professor of Medical Informatics Department of Computer Science University of Manchester Manchester M13 9PL, UK TEL: +44-161-275-6188/6149/7183 FAX: +44-161-275-6236/6204 Room: 2.88a, Kilburn Building email: rector@cs.man.ac.uk web: www.cs.man.ac.uk/mig www.opengalen.org www.clinical-escience.org
Received on Friday, 30 April 2004 18:35:13 UTC