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Re: (Round 2) Proposed Extensions to OWL

From: Thomas B. Passin <tpassin@comcast.net>
Date: Tue, 8 Jul 2003 18:01:36 -0400
Message-ID: <001801c3459c$808f8550$6401a8c0@tbp1>
To: <www-rdf-interest@w3.org>
Cc: "Costello,Roger L." <costello@mitre.org>

[Roger L. Costello" <costello@mitre.org>
To: <www-rdf-interest@w3.org>
Cc: <tpassin@comcast.net>; "Costello,Roger L." <costello@mitre.org>
Sent: Tuesday, July 08, 2003 1:17 PM
Subject: Re: (Round 2) Proposed Extensions to OWL


> Tom, I have read your latest proposal several times.  Let me see if I
> understand it.
>
> The idea is to define an ontology of standard functions.  For example,
> this defines how to transform miles into kilometers:
>
> Standard Functions Ontology:
>
> <owlx:Transform rdf:ID="MilesToKilometers">
>       <owlx:tolerance>5%</owlx:tolerance>
>       <owlx:inputValue>miles</owlx:inputValue>
>       <owlx:outputValue>kilometers</owlx:outputValue>
>       <owlx:inputUnits rdf:resource="#Miles"/>
>       <owlx:outputUnits rdf:resource="#Kilometers"/>
>       <owlx:transform>miles = kilometers * 0.62</owlx:transform>
> </owlx:Transform>
>

This is not quite what I was thinking about. The example I gave was for a
specific instance of a Transform.  In the instance, the inputValue and
outputValue properties would actually contain the URIs for the corresponding
resources.  So it would not be

<owlx:outputValue>kilometers</owlx:outputValue>

but

<owlx:outputValue>SomeInstanceOfaLengthValue</owlx:outputValue>

Of course, with OWL and RDFS you would be able to constrain what kind of
things are allowed to go into those slots, but I only showed an example of
an actual instance.

Furthermore,

<owlx:transform>miles = kilometers * 0.62</owlx:transform>

is not quite what I had.   I referred to an (so far imaginary) transform
resource that I called "G", which was unspecified since I am not clear yet
how to specify it.  I seriously doubt that we would want to use an unparsed
string for this.  Anyway, I am fairly sure that we should make the
transform - or maybe its type -  a resource on its own, so that it can be
properly characterized.

> Suppose an application were to receive this document:
>
> <River rdf:ID="Yangtze">
>    <length>
>       <Length>
>          <measurement>
>             <LengthMeasurement>
>                 <measurementValue>
>                    <LengthValue>
>                       <numericalValue>3914</numericalValue>
>                       <unitSpecification rdf:resource="#Miles"/>
>                    </LengthValue>
>                </measurementValue>
>                <precision>...</precision>
>                <source>...</source>
>             </LengthMeasurement>
>          </measurement>
>       </Length>
>    </length>
> </River>
>
> And suppose the application wanted to convert the length data in the
> document to a value with units of kilometers.
>
> The application would "consult" the Standard Functions Ontology for a
> Transform which has inputUnits = Miles and outputUnits = Kilometers.
> The transform property then details how to convert the numerical miles
> value into a numerical kilometers value.
>
> Is this an accurate summary of your proposal?  /Roger
>

More or less.  The app would have to look up the transform (type) for a
LengthValue that matched the input and output units.  I say a "LengthValue"
because maybe for some other kind of measurement, a different transform
would be more appropriate.  that remains for a more detailed analysis, I
would say.

 In addition to computing the conversion, the app would be able to create an
instance of the transform, similar to my example, and also of the resulting
LengthValue, and stick those sets of statements back into the data store.

Everything should be specifiable in OWL except for the actual math part.

Cheers,

Tom P
Received on Tuesday, 8 July 2003 17:57:32 GMT

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