Re: DIWG Requests Guidance on Ontologies for Units

Hi Rhys,

Please allow me to introduce myself.  I have recently been added as  
co-chair of the SWBP and am trying my best to fill Guus' shoes while he  
is on holiday.

The SWBP discussed your requirement for finding existing ontologies for  
units during its telecon yesterday, 22 July.  Some URLs you may wish to  
see are:

   The SWEET ontology is at http://sweet.jpl.nasa.gov/ontology/units.owl
    
http://www.scadaonweb.com/publications/ontologies_v2/ 
ontologies_list.html includes quantity and units ontologies in OWL.

Although no formal decision was reached, there was substantial interest  
in assisting your WG on this important topic.  It would help us if you  
could more fully define your requirements.  Could you please review the  
above URLs (and suggest others if you have found good ones) and let us  
know how close they are to what you would like to see?  Thanks.  It is  
important for us to determine whether we should be looking at finding,  
using, modifying or creating an ontology to suit.

Regards,
Dave
--
David Wood
CTO, Tucana Technologies, Inc.
http://www.tucanatech.com
--------------------> Information Fusion. Tucana. <--------------------

On Jul 2, 2004, at 05:42, Rhys Lewis wrote:

>
> Hello Guus,
>
> One of the areas of interest of the Device Independence Working Group  
> relates to the physical characteristics of devices used to access web  
> sites. In trying to specify these characteristics we find that we have  
> a need to define the physical units in which they may be represented.  
> For consistency with other W3C specifications, such as CSS, we need to  
> represent a reasonably wide range of units. For example, in length  
> measurements we need to represent inches, centimeters, picas, points  
> and so on.
>
> We view the information we are trying to represent as metadata, and  
> hence we are using RDF as the underlying technology. In addition, we  
> would like to be able to represent the units associated with these  
> characteristics as URIs.
>
> At the risk of exposing to public scrutiny just what an RDF neophyte I  
> am, I believe we'd like to be able to construct statements such as:
>
>   <dc:UsableDisplayWidth rdf:ID="cpcUW">
>       <dc:lengthValue rdf:datatype="&xs;decimal">0.152</dc:lengthValue>
>       <dc:lengthUnit  
> rdf:resource="http://sweet.jpl.nasa.gov/ontology/units.owl#meter"/>
>   </dc:UsableDisplayWidth>
>
> In this example, UsableDisplayWidth is a class for the particular  
> characteristic, lengthValue the value of the length and lengthUnit the  
> physical units associated with lengthValue. The particular  
> rdf:resource value is the definition of meter in the SWEET units  
> ontology. &xs; is an entity containing the base URI of the XML schema  
> datatypes.
>
> On the assumption that this approach is appropriate, we are interested  
> in finding existing Ontologies that we could reference using URIs and  
> that would provide identification for additional units.
>
> Stuart Williams from the TAG pointed us to the SWEET ontologies, but  
> suggested that we contact SWBP-WG to see if you had any additional  
> recommendations.
>
> Any guidance you could give on associating units with values or or  
> pointers to appropriate ontologies would be very much appreciated.
>
> Best wishes
> Rhys Lewis, Chair DIWG
>

Received on Friday, 23 July 2004 16:17:23 UTC