- From: Jos De_Roo <jos.deroo@agfa.com>
- Date: Sun, 15 Jun 2003 14:28:14 +0200
- To: "Monika Solanki <monika" <monika@dmu.ac.uk>
- Cc: semanticweb <semanticweb@yahoogroups.com>, www-rdf-interest@w3.org, www-ws@w3.org, www-ws-request@w3.org
Hi Monika, conceptually there should be no problem to mix RDF instance data and OWL ontologies. In my experience I even mix it with log: and math: formulae (using N3) to find proofs etc... -- Jos De Roo, AGFA http://www.agfa.com/w3c/jdroo/ Monika Solanki <monika@dmu.ac To: www-ws@w3.org, www-rdf-interest@w3.org, semanticweb .uk> <semanticweb@yahoogroups.com> Sent by: cc: www-ws-request Subject: A problem with OWL Validator @w3.org 2003-06-15 12:56 PM Hi, I have an OWL file, in which I have included some instances as well. When I parse the file without the instances, it does not give me any error, however when I do it with instances, it gives me loads of warning like, Implicit Property, Undefined Resource, Invalid namespace. I fail to understand if my ontology is wrongly written or is it wrong to include instances in the same file. Has anyone come across such errors before. Please Help. Thanks Monika Roger L. Costello wrote: Jos De_Roo wrote: we tend to use RDF interpretation properties for that and math: properties and N3 conversion rules such as eg {?X eg:length-in ?Y} => {?X eg:length-cm (?Y 2.54).math:product}. {?X eg:length-cm ?Y} => {?X eg:length-in (?Y 2.54).math:quotient}. [snip] Hi Jos, Does this have an XML syntax? My interest is in how to express the mathematical relationships using an XML syntax. /Roger "Roger L. Costello" <costello@mitre.org> To: www-rdf-interest@w3.org Sent by: cc: robin.berjon@expway.fr, "Costello,Roger L." <costello@mitre.org> www-rdf-interest-requ Subject: Proposed extensions to OWL? est@w3.org 2003-06-14 01:20 PM Hi Folks, Yesterday I sent out a message asking about technologies to express mathematical relationships. Robin Berjon responded with a very inte resting idea. I would like to get your thoughts on it, and see if collectively we can come up with something cool. First I will show you a slightly modified version of Robin's proposal, then I will show Robin's original proposal. Robin's Idea Slightly Modified The idea is to extend OWL and base the solution on xPath. Suppose that I would like to state that these two properties are equivalent via a conversion factor: length-in, length-cm i.e., length in inches, and length in centimeters The conversion factor is: length-in = length-cm / 2.54 length-cm = length-in * 2.54 With today's OWL here is how you would define these properties: <owl:DatatypeProperty rdf:ID="length-in"> <rdfs:range rdf:resourse="&xsd;decimal"/> </owl:DatatypeProperty> <owl:DatatypeProperty rdf:ID="length-cm"> <rdfs:range rdf:resourse="&xsd;de cimal"/> </owl:DatatypeProperty> The proposal is to extend OWL to allow you to assert that these two properties are equivalent by the above conversion factor. Here's how it might look: <owl:DatatypeProperty rdf:ID="length-in"> <owl:equivalentProperty rdf:resource="#length-cm" owl-x:conversionFactor="current() * 2.54"/> <rdfs:range rdf:resourse="&xsd;decimal"/> </owl:DatatypeProperty> <owl:DatatypeProperty rdf:ID="length-cm"> <owl:equivalentProperty rdf:resource="#length-in" owl-x:conversionFactor="current() / 2.54"/> <rdfs:range rdf:resourse="&xsd;decimal"/> </owl:DatatypeProperty> where: owl-x is an OWL eXtension namespace, current() is the xPath function referring to the current node. Now let me show you Robin's idea: Robin's idea is also to base the solution on xPath. Here's what Robin said: "For instance: <foo:PropertyEquivalence from='measure:inch' to='measure:cm' convert='$in_1 * 2.54'/> <foo:PropertyEquivalence from='measure:cm' to='measure:in' convert='$in_1 div 2.54'/> would allow you to declare that the following are equivalent: <geo:Distance> <measure:inch>2</measure:inch> </geo:Distance> <geo:Distance> <measure:cm>5.08</measure:cm> </geo:Distance> You could allow for multiple inputs to your binding: <foo:PropertyEquivalence from='size:width/measure:meter size:length/measure:meter' to='size:surface/measure:squareMeter' convert='$in_1 * $in_2'/> and perhaps equivalentize, dep ending on whether it makes sense in that context: <flat:Bedroom> <size:width><measure:meter>4</measure:meter></size:width> <size:length><measure:meter>5</measure:meter></size:length> </flat:Bedroom> <flat:Bedroom> <size:surface> <measure:squareMeter>20</measure:squareMeter> </size:surface> </flat:Bedroom> so that given the first you could still query for flat:Bedrooms that are larger than 20sqm. You may need to throw in stuff from EXSLT Math if you want more than XPath provides." .... Okay, those are the two ideas thus far. What do you think? Feel free to add your own ideas. If this whole approach is bad, feel free to say so. The intent here is to brainstorm. If these conversion rules are better stated using another technology (e.g., RuleML) please say so. /Roger -- >**<>**<>**<>**<>**<>**<>**<>**<>**<>**< Monika Solanki De Montfort University Software Technology Research Laboratory Hawthorn building, H00.18 The Gateway. Leicester LE1 9BH, UK phone: +44 (0)116 250 6170 intern: 6170 email: monika@dmu.ac.uk web: http://www.cse.dmu.ac.uk/~monika/ >**<>**<>**<>**<>**<>**<>**<>**<>**<>**< "NOTE: The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. 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Received on Sunday, 15 June 2003 08:28:32 UTC